1 # SOME DESCRIPTIVE TITLE
2 # Copyright (C) YEAR Free Software Foundation, Inc.
3 # This file is distributed under the same license as the PACKAGE package.
4 # FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
9 "Project-Id-Version: PACKAGE VERSION\n"
10 "POT-Creation-Date: 2015-01-04 23:49+0900\n"
11 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
12 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
13 "Language-Team: LANGUAGE <LL@li.org>\n"
16 "Content-Type: text/plain; charset=UTF-8\n"
17 "Content-Transfer-Encoding: 8bit\n"
20 #: build/C/man3/bsd_signal.3:25
26 #: build/C/man3/bsd_signal.3:25
32 #: build/C/man3/bsd_signal.3:25 build/C/man2/eventfd.2:22 build/C/man2/getitimer.2:12 build/C/man3/gsignal.3:27 build/C/man2/kill.2:44 build/C/man2/killpg.2:42 build/C/man2/pause.2:30 build/C/man2/prctl.2:52 build/C/man3/profil.3:28 build/C/man3/psignal.3:30 build/C/man3/raise.3:29 build/C/man2/restart_syscall.2:33 build/C/man2/rt_sigqueueinfo.2:25 build/C/man2/s390_runtime_instr.2:25 build/C/man2/sgetmask.2:26 build/C/man2/sigaction.2:47 build/C/man2/sigaltstack.2:27 build/C/man7/sigevent.7:26 build/C/man3/siginterrupt.3:31 build/C/man2/signal.2:36 build/C/man7/signal.7:46 build/C/man2/signalfd.2:20 build/C/man3/sigpause.3:25 build/C/man2/sigpending.2:29 build/C/man2/sigprocmask.2:29 build/C/man3/sigqueue.3:28 build/C/man2/sigreturn.2:30 build/C/man3/sigset.3:26 build/C/man3/sigsetops.3:31 build/C/man2/sigsuspend.2:29 build/C/man3/sigvec.3:26 build/C/man3/sigwait.3:26 build/C/man2/sigwaitinfo.2:25 build/C/man3/sysv_signal.3:25 build/C/man2/timer_create.2:33 build/C/man2/timer_delete.2:26 build/C/man2/timer_getoverrun.2:26 build/C/man2/timer_settime.2:26 build/C/man2/timerfd_create.2:22 build/C/man2/tkill.2:29 build/C/man2/wait.2:49 build/C/man2/wait4.2:33
34 msgid "Linux Programmer's Manual"
38 #: build/C/man3/bsd_signal.3:26 build/C/man2/eventfd.2:23 build/C/man2/getitimer.2:13 build/C/man3/gsignal.3:28 build/C/man2/kill.2:45 build/C/man2/killpg.2:43 build/C/man2/pause.2:31 build/C/man2/prctl.2:53 build/C/man3/profil.3:29 build/C/man3/psignal.3:31 build/C/man3/raise.3:30 build/C/man2/restart_syscall.2:34 build/C/man2/rt_sigqueueinfo.2:26 build/C/man2/s390_runtime_instr.2:26 build/C/man2/sgetmask.2:27 build/C/man2/sigaction.2:48 build/C/man2/sigaltstack.2:28 build/C/man7/sigevent.7:27 build/C/man3/siginterrupt.3:32 build/C/man2/signal.2:37 build/C/man7/signal.7:47 build/C/man2/signalfd.2:21 build/C/man3/sigpause.3:26 build/C/man2/sigpending.2:30 build/C/man2/sigprocmask.2:30 build/C/man3/sigqueue.3:29 build/C/man2/sigreturn.2:31 build/C/man3/sigset.3:27 build/C/man3/sigsetops.3:32 build/C/man2/sigsuspend.2:30 build/C/man3/sigvec.3:27 build/C/man3/sigwait.3:27 build/C/man2/sigwaitinfo.2:26 build/C/man3/sysv_signal.3:26 build/C/man2/timer_create.2:34 build/C/man2/timer_delete.2:27 build/C/man2/timer_getoverrun.2:27 build/C/man2/timer_settime.2:27 build/C/man2/timerfd_create.2:23 build/C/man2/tkill.2:30 build/C/man2/wait.2:50 build/C/man2/wait4.2:34
44 #: build/C/man3/bsd_signal.3:28
45 msgid "bsd_signal - signal handling with BSD semantics"
49 #: build/C/man3/bsd_signal.3:28 build/C/man2/eventfd.2:25 build/C/man2/getitimer.2:15 build/C/man3/gsignal.3:30 build/C/man2/kill.2:47 build/C/man2/killpg.2:45 build/C/man2/pause.2:33 build/C/man2/prctl.2:55 build/C/man3/profil.3:31 build/C/man3/psignal.3:33 build/C/man3/raise.3:32 build/C/man2/restart_syscall.2:36 build/C/man2/rt_sigqueueinfo.2:28 build/C/man2/s390_runtime_instr.2:28 build/C/man2/sgetmask.2:29 build/C/man2/sigaction.2:50 build/C/man2/sigaltstack.2:30 build/C/man7/sigevent.7:29 build/C/man3/siginterrupt.3:34 build/C/man2/signal.2:39 build/C/man2/signalfd.2:23 build/C/man3/sigpause.3:28 build/C/man2/sigpending.2:32 build/C/man2/sigprocmask.2:32 build/C/man3/sigqueue.3:31 build/C/man2/sigreturn.2:33 build/C/man3/sigset.3:29 build/C/man3/sigsetops.3:35 build/C/man2/sigsuspend.2:32 build/C/man3/sigvec.3:29 build/C/man3/sigwait.3:29 build/C/man2/sigwaitinfo.2:28 build/C/man3/sysv_signal.3:28 build/C/man2/timer_create.2:36 build/C/man2/timer_delete.2:29 build/C/man2/timer_getoverrun.2:29 build/C/man2/timer_settime.2:30 build/C/man2/timerfd_create.2:26 build/C/man2/tkill.2:32 build/C/man2/wait.2:52 build/C/man2/wait4.2:36
55 #: build/C/man3/bsd_signal.3:30
56 msgid "B<#define _XOPEN_SOURCE> /* See feature_test_macros(7) */"
60 #: build/C/man3/bsd_signal.3:32 build/C/man2/killpg.2:47 build/C/man2/sigaltstack.2:32 build/C/man2/signal.2:41 build/C/man2/sigpending.2:34 build/C/man2/sigprocmask.2:34 build/C/man3/sigqueue.3:33 build/C/man3/sigset.3:31 build/C/man3/sigsetops.3:37 build/C/man2/sigsuspend.2:34 build/C/man3/sigvec.3:31 build/C/man3/sysv_signal.3:32
61 msgid "B<#include E<lt>signal.hE<gt>>"
65 #: build/C/man3/bsd_signal.3:34 build/C/man2/signal.2:43 build/C/man3/sigset.3:33 build/C/man3/sysv_signal.3:34
66 msgid "B<typedef void (*sighandler_t)(int);>"
70 #: build/C/man3/bsd_signal.3:36
71 msgid "B<sighandler_t bsd_signal(int >I<signum>B<, sighandler_t >I<handler>B<);>"
75 #: build/C/man3/bsd_signal.3:36 build/C/man2/eventfd.2:29 build/C/man2/getitimer.2:24 build/C/man3/gsignal.3:49 build/C/man2/kill.2:65 build/C/man2/killpg.2:60 build/C/man2/pause.2:37 build/C/man2/prctl.2:62 build/C/man3/profil.3:46 build/C/man3/psignal.3:56 build/C/man3/raise.3:38 build/C/man2/restart_syscall.2:41 build/C/man2/rt_sigqueueinfo.2:38 build/C/man2/s390_runtime_instr.2:34 build/C/man2/sgetmask.2:36 build/C/man2/sigaction.2:70 build/C/man2/sigaltstack.2:51 build/C/man7/sigevent.7:52 build/C/man3/siginterrupt.3:55 build/C/man2/signal.2:45 build/C/man7/signal.7:49 build/C/man2/signalfd.2:27 build/C/man3/sigpause.3:36 build/C/man2/sigpending.2:46 build/C/man2/sigprocmask.2:47 build/C/man3/sigqueue.3:43 build/C/man2/sigreturn.2:35 build/C/man3/sigset.3:58 build/C/man3/sigsetops.3:63 build/C/man2/sigsuspend.2:46 build/C/man3/sigvec.3:49 build/C/man3/sigwait.3:45 build/C/man2/sigwaitinfo.2:46 build/C/man3/sysv_signal.3:36 build/C/man2/timer_create.2:54 build/C/man2/timer_delete.2:45 build/C/man2/timer_getoverrun.2:45 build/C/man2/timer_settime.2:50 build/C/man2/timerfd_create.2:38 build/C/man2/tkill.2:41 build/C/man2/wait.2:83 build/C/man2/wait4.2:67
81 #: build/C/man3/bsd_signal.3:41
83 "The B<bsd_signal>() function takes the same arguments, and performs the "
84 "same task, as B<signal>(2)."
88 #: build/C/man3/bsd_signal.3:54
90 "The difference between the two is that B<bsd_signal>() is guaranteed to "
91 "provide reliable signal semantics, that is: a) the disposition of the signal "
92 "is not reset to the default when the handler is invoked; b) delivery of "
93 "further instances of the signal is blocked while the signal handler is "
94 "executing; and c) if the handler interrupts a blocking system call, then the "
95 "system call is automatically restarted. A portable application cannot rely "
96 "on B<signal>(2) to provide these guarantees."
100 #: build/C/man3/bsd_signal.3:54 build/C/man2/eventfd.2:222 build/C/man2/getitimer.2:129 build/C/man2/kill.2:100 build/C/man2/killpg.2:89 build/C/man2/pause.2:42 build/C/man2/prctl.2:804 build/C/man3/profil.3:68 build/C/man3/psignal.3:89 build/C/man3/raise.3:61 build/C/man2/restart_syscall.2:88 build/C/man2/rt_sigqueueinfo.2:129 build/C/man2/s390_runtime_instr.2:54 build/C/man2/sgetmask.2:59 build/C/man2/sigaction.2:671 build/C/man2/sigaltstack.2:133 build/C/man3/siginterrupt.3:73 build/C/man2/signal.2:97 build/C/man2/signalfd.2:251 build/C/man3/sigpause.3:48 build/C/man2/sigpending.2:53 build/C/man2/sigprocmask.2:93 build/C/man3/sigqueue.3:83 build/C/man2/sigreturn.2:65 build/C/man3/sigset.3:129 build/C/man3/sigsetops.3:107 build/C/man2/sigsuspend.2:70 build/C/man3/sigvec.3:199 build/C/man3/sigwait.3:69 build/C/man2/sigwaitinfo.2:105 build/C/man3/sysv_signal.3:51 build/C/man2/timer_create.2:169 build/C/man2/timer_delete.2:53 build/C/man2/timer_getoverrun.2:82 build/C/man2/timer_settime.2:173 build/C/man2/timerfd_create.2:294 build/C/man2/tkill.2:88 build/C/man2/wait.2:355 build/C/man2/wait4.2:132
106 #: build/C/man3/bsd_signal.3:60
108 "The B<bsd_signal>() function returns the previous value of the signal "
109 "handler, or B<SIG_ERR> on error."
113 #: build/C/man3/bsd_signal.3:60 build/C/man2/eventfd.2:229 build/C/man2/getitimer.2:134 build/C/man2/kill.2:105 build/C/man2/killpg.2:94 build/C/man2/pause.2:53 build/C/man2/prctl.2:824 build/C/man2/restart_syscall.2:92 build/C/man2/rt_sigqueueinfo.2:134 build/C/man2/s390_runtime_instr.2:65 build/C/man2/sgetmask.2:64 build/C/man2/sigaction.2:676 build/C/man2/sigaltstack.2:137 build/C/man3/siginterrupt.3:83 build/C/man2/signal.2:105 build/C/man2/signalfd.2:265 build/C/man2/sigpending.2:59 build/C/man2/sigprocmask.2:99 build/C/man3/sigqueue.3:91 build/C/man3/sigset.3:154 build/C/man3/sigsetops.3:127 build/C/man2/sigsuspend.2:76 build/C/man3/sigvec.3:216 build/C/man3/sigwait.3:74 build/C/man2/sigwaitinfo.2:114 build/C/man3/sysv_signal.3:57 build/C/man2/timer_create.2:177 build/C/man2/timer_delete.2:60 build/C/man2/timer_getoverrun.2:90 build/C/man2/timer_settime.2:182 build/C/man2/timerfd_create.2:309 build/C/man2/tkill.2:92 build/C/man2/wait.2:385 build/C/man2/wait4.2:135
119 #: build/C/man3/bsd_signal.3:63 build/C/man3/sysv_signal.3:60
120 msgid "As for B<signal>(2)."
124 #: build/C/man3/bsd_signal.3:63 build/C/man3/raise.3:64 build/C/man3/siginterrupt.3:87 build/C/man3/sigpause.3:56 build/C/man3/sigqueue.3:114 build/C/man3/sigsetops.3:132 build/C/man3/sigvec.3:221 build/C/man3/sigwait.3:80 build/C/man3/sysv_signal.3:60
130 #: build/C/man3/bsd_signal.3:64 build/C/man3/raise.3:65 build/C/man3/siginterrupt.3:88 build/C/man3/sigpause.3:57 build/C/man3/sigqueue.3:115 build/C/man3/sigsetops.3:133 build/C/man3/sigvec.3:222 build/C/man3/sigwait.3:81 build/C/man3/sysv_signal.3:61
132 msgid "Multithreading (see pthreads(7))"
136 #: build/C/man3/bsd_signal.3:68
137 msgid "The B<bsd_signal>() function is thread-safe."
141 #: build/C/man3/bsd_signal.3:68 build/C/man2/eventfd.2:266 build/C/man2/getitimer.2:155 build/C/man3/gsignal.3:95 build/C/man2/kill.2:121 build/C/man2/killpg.2:111 build/C/man2/pause.2:57 build/C/man2/prctl.2:1070 build/C/man3/profil.3:70 build/C/man3/psignal.3:99 build/C/man3/raise.3:69 build/C/man2/restart_syscall.2:100 build/C/man2/rt_sigqueueinfo.2:176 build/C/man2/s390_runtime_instr.2:81 build/C/man2/sgetmask.2:73 build/C/man2/sigaction.2:688 build/C/man2/sigaltstack.2:158 build/C/man7/sigevent.7:130 build/C/man3/siginterrupt.3:93 build/C/man2/signal.2:110 build/C/man7/signal.7:872 build/C/man2/signalfd.2:307 build/C/man3/sigpause.3:61 build/C/man2/sigpending.2:64 build/C/man2/sigprocmask.2:112 build/C/man3/sigqueue.3:119 build/C/man2/sigreturn.2:68 build/C/man3/sigset.3:173 build/C/man3/sigsetops.3:145 build/C/man2/sigsuspend.2:84 build/C/man3/sigvec.3:241 build/C/man3/sigwait.3:85 build/C/man2/sigwaitinfo.2:133 build/C/man3/sysv_signal.3:65 build/C/man2/timer_create.2:195 build/C/man2/timer_delete.2:67 build/C/man2/timer_getoverrun.2:97 build/C/man2/timer_settime.2:207 build/C/man2/timerfd_create.2:378 build/C/man2/tkill.2:109 build/C/man2/wait.2:423 build/C/man2/wait4.2:138
143 msgid "CONFORMING TO"
147 #: build/C/man3/bsd_signal.3:75
149 "4.2BSD, POSIX.1-2001. POSIX.1-2008 removes the specification of "
150 "B<bsd_signal>(), recommending the use of B<sigaction>(2) instead."
154 #: build/C/man3/bsd_signal.3:75 build/C/man2/eventfd.2:271 build/C/man2/getitimer.2:165 build/C/man2/kill.2:123 build/C/man2/killpg.2:115 build/C/man3/raise.3:71 build/C/man2/restart_syscall.2:102 build/C/man2/rt_sigqueueinfo.2:178 build/C/man2/s390_runtime_instr.2:84 build/C/man2/sgetmask.2:75 build/C/man2/sigaction.2:691 build/C/man2/sigaltstack.2:160 build/C/man2/signal.2:112 build/C/man2/signalfd.2:312 build/C/man3/sigpause.3:65 build/C/man2/sigpending.2:66 build/C/man2/sigprocmask.2:114 build/C/man3/sigqueue.3:121 build/C/man2/sigreturn.2:74 build/C/man3/sigset.3:190 build/C/man3/sigsetops.3:147 build/C/man2/sigsuspend.2:86 build/C/man3/sigvec.3:247 build/C/man3/sigwait.3:87 build/C/man2/sigwaitinfo.2:135 build/C/man3/sysv_signal.3:67 build/C/man2/timer_create.2:197 build/C/man2/timer_getoverrun.2:99 build/C/man2/tkill.2:115 build/C/man2/wait.2:425 build/C/man2/wait4.2:147
160 #: build/C/man3/bsd_signal.3:81
161 msgid "Use of B<bsd_signal>() should be avoided; use B<sigaction>(2) instead."
165 #: build/C/man3/bsd_signal.3:92
167 "On modern Linux systems, B<bsd_signal>() and B<signal>(2) are equivalent. "
168 "But on older systems, B<signal>(2) provided unreliable signal semantics; "
169 "see B<signal>(2) for details."
173 #: build/C/man3/bsd_signal.3:99 build/C/man3/sysv_signal.3:92
175 "The use of I<sighandler_t> is a GNU extension; this type is defined only if "
176 "the B<_GNU_SOURCE> feature test macro is defined."
180 #: build/C/man3/bsd_signal.3:99 build/C/man2/eventfd.2:417 build/C/man2/getitimer.2:246 build/C/man3/gsignal.3:103 build/C/man2/kill.2:171 build/C/man2/killpg.2:134 build/C/man2/pause.2:59 build/C/man2/prctl.2:1084 build/C/man3/profil.3:81 build/C/man3/psignal.3:113 build/C/man3/raise.3:82 build/C/man2/restart_syscall.2:135 build/C/man2/rt_sigqueueinfo.2:188 build/C/man2/s390_runtime_instr.2:88 build/C/man2/sgetmask.2:89 build/C/man2/sigaction.2:804 build/C/man2/sigaltstack.2:234 build/C/man7/sigevent.7:132 build/C/man3/siginterrupt.3:102 build/C/man2/signal.2:278 build/C/man7/signal.7:884 build/C/man2/signalfd.2:433 build/C/man3/sigpause.3:111 build/C/man2/sigpending.2:91 build/C/man2/sigprocmask.2:144 build/C/man3/sigqueue.3:154 build/C/man2/sigreturn.2:123 build/C/man3/sigset.3:266 build/C/man3/sigsetops.3:186 build/C/man2/sigsuspend.2:108 build/C/man3/sigvec.3:272 build/C/man3/sigwait.3:94 build/C/man2/sigwaitinfo.2:201 build/C/man3/sysv_signal.3:92 build/C/man2/timer_create.2:410 build/C/man2/timer_delete.2:69 build/C/man2/timer_getoverrun.2:131 build/C/man2/timer_settime.2:212 build/C/man2/timerfd_create.2:548 build/C/man2/tkill.2:124 build/C/man2/wait.2:635 build/C/man2/wait4.2:165
186 #: build/C/man3/bsd_signal.3:104
187 msgid "B<sigaction>(2), B<signal>(2), B<sysv_signal>(3), B<signal>(7)"
191 #: build/C/man3/bsd_signal.3:104 build/C/man2/eventfd.2:428 build/C/man2/getitimer.2:253 build/C/man3/gsignal.3:107 build/C/man2/kill.2:181 build/C/man2/killpg.2:140 build/C/man2/pause.2:64 build/C/man2/prctl.2:1087 build/C/man3/profil.3:87 build/C/man3/psignal.3:118 build/C/man3/raise.3:89 build/C/man2/restart_syscall.2:144 build/C/man2/rt_sigqueueinfo.2:196 build/C/man2/s390_runtime_instr.2:91 build/C/man2/sgetmask.2:92 build/C/man2/sigaction.2:825 build/C/man2/sigaltstack.2:241 build/C/man7/sigevent.7:142 build/C/man3/siginterrupt.3:104 build/C/man2/signal.2:297 build/C/man7/signal.7:919 build/C/man2/signalfd.2:446 build/C/man3/sigpause.3:119 build/C/man2/sigpending.2:99 build/C/man2/sigprocmask.2:155 build/C/man3/sigqueue.3:162 build/C/man2/sigreturn.2:130 build/C/man3/sigset.3:276 build/C/man3/sigsetops.3:191 build/C/man2/sigsuspend.2:118 build/C/man3/sigvec.3:282 build/C/man3/sigwait.3:102 build/C/man2/sigwaitinfo.2:213 build/C/man3/sysv_signal.3:97 build/C/man2/timer_create.2:425 build/C/man2/timer_delete.2:75 build/C/man2/timer_getoverrun.2:141 build/C/man2/timer_settime.2:216 build/C/man2/timerfd_create.2:560 build/C/man2/tkill.2:129 build/C/man2/wait.2:647 build/C/man2/wait4.2:172
197 #: build/C/man3/bsd_signal.3:112 build/C/man2/eventfd.2:436 build/C/man2/getitimer.2:261 build/C/man3/gsignal.3:115 build/C/man2/kill.2:189 build/C/man2/killpg.2:148 build/C/man2/pause.2:72 build/C/man2/prctl.2:1095 build/C/man3/profil.3:95 build/C/man3/psignal.3:126 build/C/man3/raise.3:97 build/C/man2/restart_syscall.2:152 build/C/man2/rt_sigqueueinfo.2:204 build/C/man2/s390_runtime_instr.2:99 build/C/man2/sgetmask.2:100 build/C/man2/sigaction.2:833 build/C/man2/sigaltstack.2:249 build/C/man7/sigevent.7:150 build/C/man3/siginterrupt.3:112 build/C/man2/signal.2:305 build/C/man7/signal.7:927 build/C/man2/signalfd.2:454 build/C/man3/sigpause.3:127 build/C/man2/sigpending.2:107 build/C/man2/sigprocmask.2:163 build/C/man3/sigqueue.3:170 build/C/man2/sigreturn.2:138 build/C/man3/sigset.3:284 build/C/man3/sigsetops.3:199 build/C/man2/sigsuspend.2:126 build/C/man3/sigvec.3:290 build/C/man3/sigwait.3:110 build/C/man2/sigwaitinfo.2:221 build/C/man3/sysv_signal.3:105 build/C/man2/timer_create.2:433 build/C/man2/timer_delete.2:83 build/C/man2/timer_getoverrun.2:149 build/C/man2/timer_settime.2:224 build/C/man2/timerfd_create.2:568 build/C/man2/tkill.2:137 build/C/man2/wait.2:655 build/C/man2/wait4.2:180
199 "This page is part of release 3.76 of the Linux I<man-pages> project. A "
200 "description of the project, information about reporting bugs, and the latest "
201 "version of this page, can be found at "
202 "\\%http://www.kernel.org/doc/man-pages/."
206 #: build/C/man2/eventfd.2:22
212 #: build/C/man2/eventfd.2:22 build/C/man2/getitimer.2:12 build/C/man3/profil.3:28 build/C/man2/signalfd.2:20
218 #: build/C/man2/eventfd.2:22 build/C/man2/getitimer.2:12 build/C/man2/kill.2:44 build/C/man2/killpg.2:42 build/C/man2/pause.2:30 build/C/man2/prctl.2:52 build/C/man3/profil.3:28 build/C/man2/restart_syscall.2:33 build/C/man2/rt_sigqueueinfo.2:25 build/C/man2/sgetmask.2:26 build/C/man2/sigaction.2:47 build/C/man2/sigaltstack.2:27 build/C/man2/signal.2:36 build/C/man7/signal.7:46 build/C/man2/signalfd.2:20 build/C/man3/sigpause.3:25 build/C/man2/sigpending.2:29 build/C/man2/sigprocmask.2:29 build/C/man3/sigqueue.3:28 build/C/man2/sigreturn.2:30 build/C/man3/sigset.3:26 build/C/man3/sigsetops.3:31 build/C/man2/sigsuspend.2:29 build/C/man3/sigvec.3:26 build/C/man3/sigwait.3:26 build/C/man2/sigwaitinfo.2:25 build/C/man2/timer_create.2:33 build/C/man2/timer_delete.2:26 build/C/man2/timer_getoverrun.2:26 build/C/man2/timer_settime.2:26 build/C/man2/timerfd_create.2:22 build/C/man2/tkill.2:29 build/C/man2/wait.2:49 build/C/man2/wait4.2:33
224 #: build/C/man2/eventfd.2:25
225 msgid "eventfd - create a file descriptor for event notification"
229 #: build/C/man2/eventfd.2:27
230 msgid "B<#include E<lt>sys/eventfd.hE<gt>>"
234 #: build/C/man2/eventfd.2:29
235 msgid "B<int eventfd(unsigned int >I<initval>B<, int >I<flags>B<);>"
239 #: build/C/man2/eventfd.2:39
241 "B<eventfd>() creates an \"eventfd object\" that can be used as an event "
242 "wait/notify mechanism by user-space applications, and by the kernel to "
243 "notify user-space applications of events. The object contains an unsigned "
244 "64-bit integer (I<uint64_t>) counter that is maintained by the kernel. "
245 "This counter is initialized with the value specified in the argument "
250 #: build/C/man2/eventfd.2:44
252 "The following values may be bitwise ORed in I<flags> to change the behavior "
257 #: build/C/man2/eventfd.2:44
259 msgid "B<EFD_CLOEXEC> (since Linux 2.6.27)"
263 #: build/C/man2/eventfd.2:54 build/C/man2/signalfd.2:95 build/C/man2/timerfd_create.2:110
265 "Set the close-on-exec (B<FD_CLOEXEC>) flag on the new file descriptor. See "
266 "the description of the B<O_CLOEXEC> flag in B<open>(2) for reasons why this "
271 #: build/C/man2/eventfd.2:54
273 msgid "B<EFD_NONBLOCK> (since Linux 2.6.27)"
277 #: build/C/man2/eventfd.2:62 build/C/man2/signalfd.2:85 build/C/man2/timerfd_create.2:100
279 "Set the B<O_NONBLOCK> file status flag on the new open file description. "
280 "Using this flag saves extra calls to B<fcntl>(2) to achieve the same "
285 #: build/C/man2/eventfd.2:62
287 msgid "B<EFD_SEMAPHORE> (since Linux 2.6.30)"
291 #: build/C/man2/eventfd.2:66
293 "Provide semaphore-like semantics for reads from the new file descriptor. "
298 #: build/C/man2/eventfd.2:70 build/C/man2/signalfd.2:99
300 "In Linux up to version 2.6.26, the I<flags> argument is unused, and must be "
305 #: build/C/man2/eventfd.2:76
307 "As its return value, B<eventfd>() returns a new file descriptor that can be "
308 "used to refer to the eventfd object. The following operations can be "
309 "performed on the file descriptor:"
313 #: build/C/man2/eventfd.2:76 build/C/man2/signalfd.2:102 build/C/man2/timerfd_create.2:218
319 #: build/C/man2/eventfd.2:86
321 "Each successful B<read>(2) returns an 8-byte integer. A B<read>(2) will "
322 "fail with the error B<EINVAL> if the size of the supplied buffer is less "
327 #: build/C/man2/eventfd.2:91
329 "The value returned by B<read>(2) is in host byte order\\(emthat is, the "
330 "native byte order for integers on the host machine."
334 #: build/C/man2/eventfd.2:98
336 "The semantics of B<read>(2) depend on whether the eventfd counter currently "
337 "has a nonzero value and whether the B<EFD_SEMAPHORE> flag was specified when "
338 "creating the eventfd file descriptor:"
342 #: build/C/man2/eventfd.2:99 build/C/man2/eventfd.2:106 build/C/man2/eventfd.2:113 build/C/man2/eventfd.2:158 build/C/man2/eventfd.2:168 build/C/man2/eventfd.2:178 build/C/man2/prctl.2:867 build/C/man2/prctl.2:872 build/C/man2/prctl.2:877 build/C/man2/prctl.2:887 build/C/man3/psignal.3:105 build/C/man3/psignal.3:109 build/C/man2/sigaction.2:309 build/C/man2/sigaction.2:324 build/C/man2/sigaction.2:340 build/C/man2/sigaction.2:355 build/C/man2/sigaction.2:402 build/C/man2/sigaction.2:438 build/C/man2/signal.2:68 build/C/man2/signal.2:73 build/C/man2/signal.2:80 build/C/man2/signal.2:224 build/C/man2/signal.2:228 build/C/man2/signal.2:244 build/C/man7/signal.7:149 build/C/man7/signal.7:157 build/C/man7/signal.7:615 build/C/man7/signal.7:617 build/C/man7/signal.7:638 build/C/man7/signal.7:672 build/C/man7/signal.7:676 build/C/man7/signal.7:683 build/C/man7/signal.7:701 build/C/man7/signal.7:707 build/C/man7/signal.7:714 build/C/man7/signal.7:719 build/C/man7/signal.7:723 build/C/man7/signal.7:742 build/C/man7/signal.7:756 build/C/man7/signal.7:767 build/C/man7/signal.7:774 build/C/man7/signal.7:783 build/C/man7/signal.7:791 build/C/man7/signal.7:797 build/C/man7/signal.7:817 build/C/man7/signal.7:831 build/C/man7/signal.7:842 build/C/man7/signal.7:845 build/C/man7/signal.7:848 build/C/man7/signal.7:851 build/C/man7/signal.7:858 build/C/man7/signal.7:864 build/C/man7/signal.7:868 build/C/man3/sigwait.3:62 build/C/man3/sigwait.3:67 build/C/man2/timer_create.2:218 build/C/man2/timer_create.2:221 build/C/man2/timer_create.2:224 build/C/man2/timer_create.2:228 build/C/man2/timer_create.2:231 build/C/man2/timer_create.2:246 build/C/man2/timer_create.2:250
348 #: build/C/man2/eventfd.2:106
350 "If B<EFD_SEMAPHORE> was not specified and the eventfd counter has a nonzero "
351 "value, then a B<read>(2) returns 8 bytes containing that value, and the "
352 "counter's value is reset to zero."
356 #: build/C/man2/eventfd.2:113
358 "If B<EFD_SEMAPHORE> was specified and the eventfd counter has a nonzero "
359 "value, then a B<read>(2) returns 8 bytes containing the value 1, and the "
360 "counter's value is decremented by 1."
364 #: build/C/man2/eventfd.2:123
366 "If the eventfd counter is zero at the time of the call to B<read>(2), then "
367 "the call either blocks until the counter becomes nonzero (at which time, the "
368 "B<read>(2) proceeds as described above) or fails with the error B<EAGAIN> "
369 "if the file descriptor has been made nonblocking."
373 #: build/C/man2/eventfd.2:124
379 #: build/C/man2/eventfd.2:141
381 "A B<write>(2) call adds the 8-byte integer value supplied in its buffer to "
382 "the counter. The maximum value that may be stored in the counter is the "
383 "largest unsigned 64-bit value minus 1 (i.e., 0xfffffffffffffffe). If the "
384 "addition would cause the counter's value to exceed the maximum, then the "
385 "B<write>(2) either blocks until a B<read>(2) is performed on the file "
386 "descriptor, or fails with the error B<EAGAIN> if the file descriptor has "
387 "been made nonblocking."
391 #: build/C/man2/eventfd.2:148
393 "A B<write>(2) will fail with the error B<EINVAL> if the size of the "
394 "supplied buffer is less than 8 bytes, or if an attempt is made to write the "
395 "value 0xffffffffffffffff."
399 #: build/C/man2/eventfd.2:148 build/C/man2/signalfd.2:140 build/C/man2/timerfd_create.2:251
401 msgid "B<poll>(2), B<select>(2) (and similar)"
405 #: build/C/man2/eventfd.2:157
407 "The returned file descriptor supports B<poll>(2) (and analogously "
408 "B<epoll>(7)) and B<select>(2), as follows:"
412 #: build/C/man2/eventfd.2:168
414 "The file descriptor is readable (the B<select>(2) I<readfds> argument; the "
415 "B<poll>(2) B<POLLIN> flag) if the counter has a value greater than 0."
419 #: build/C/man2/eventfd.2:178
421 "The file descriptor is writable (the B<select>(2) I<writefds> argument; the "
422 "B<poll>(2) B<POLLOUT> flag) if it is possible to write a value of at least "
423 "\"1\" without blocking."
427 #: build/C/man2/eventfd.2:198
429 "If an overflow of the counter value was detected, then B<select>(2) "
430 "indicates the file descriptor as being both readable and writable, and "
431 "B<poll>(2) returns a B<POLLERR> event. As noted above, B<write>(2) can "
432 "never overflow the counter. However an overflow can occur if 2^64 eventfd "
433 "\"signal posts\" were performed by the KAIO subsystem (theoretically "
434 "possible, but practically unlikely). If an overflow has occurred, then "
435 "B<read>(2) will return that maximum I<uint64_t> value (i.e., "
436 "0xffffffffffffffff)."
440 #: build/C/man2/eventfd.2:205
442 "The eventfd file descriptor also supports the other file-descriptor "
443 "multiplexing APIs: B<pselect>(2) and B<ppoll>(2)."
447 #: build/C/man2/eventfd.2:205 build/C/man2/signalfd.2:160 build/C/man2/timerfd_create.2:269
453 #: build/C/man2/eventfd.2:210
455 "When the file descriptor is no longer required it should be closed. When "
456 "all file descriptors associated with the same eventfd object have been "
457 "closed, the resources for object are freed by the kernel."
461 #: build/C/man2/eventfd.2:222
463 "A copy of the file descriptor created by B<eventfd>() is inherited by the "
464 "child produced by B<fork>(2). The duplicate file descriptor is associated "
465 "with the same eventfd object. File descriptors created by B<eventfd>() are "
466 "preserved across B<execve>(2), unless the close-on-exec flag has been set."
470 #: build/C/man2/eventfd.2:229
472 "On success, B<eventfd>() returns a new eventfd file descriptor. On error, "
473 "-1 is returned and I<errno> is set to indicate the error."
477 #: build/C/man2/eventfd.2:230 build/C/man2/getitimer.2:142 build/C/man2/kill.2:106 build/C/man2/killpg.2:95 build/C/man2/prctl.2:829 build/C/man2/prctl.2:834 build/C/man2/prctl.2:846 build/C/man2/prctl.2:851 build/C/man2/prctl.2:860 build/C/man2/prctl.2:900 build/C/man2/prctl.2:910 build/C/man2/prctl.2:918 build/C/man2/prctl.2:929 build/C/man2/prctl.2:938 build/C/man2/prctl.2:952 build/C/man2/prctl.2:964 build/C/man2/prctl.2:975 build/C/man2/rt_sigqueueinfo.2:141 build/C/man2/s390_runtime_instr.2:66 build/C/man2/sigaction.2:681 build/C/man2/sigaltstack.2:142 build/C/man3/siginterrupt.3:84 build/C/man2/signal.2:106 build/C/man2/signalfd.2:271 build/C/man2/signalfd.2:279 build/C/man2/sigprocmask.2:107 build/C/man3/sigqueue.3:98 build/C/man3/sigsetops.3:128 build/C/man3/sigwait.3:75 build/C/man2/sigwaitinfo.2:129 build/C/man2/timer_create.2:181 build/C/man2/timer_delete.2:61 build/C/man2/timer_getoverrun.2:91 build/C/man2/timer_settime.2:191 build/C/man2/timer_settime.2:199 build/C/man2/timerfd_create.2:312 build/C/man2/timerfd_create.2:320 build/C/man2/timerfd_create.2:356 build/C/man2/timerfd_create.2:363 build/C/man2/timerfd_create.2:369 build/C/man2/tkill.2:93 build/C/man2/wait.2:418
483 #: build/C/man2/eventfd.2:234
484 msgid "An unsupported value was specified in I<flags>."
488 #: build/C/man2/eventfd.2:234 build/C/man2/signalfd.2:286 build/C/man2/timerfd_create.2:327
494 #: build/C/man2/eventfd.2:237
495 msgid "The per-process limit on open file descriptors has been reached."
499 #: build/C/man2/eventfd.2:237 build/C/man2/signalfd.2:289 build/C/man2/timerfd_create.2:330
505 #: build/C/man2/eventfd.2:241 build/C/man2/signalfd.2:293 build/C/man2/timerfd_create.2:334
506 msgid "The system-wide limit on the total number of open files has been reached."
510 #: build/C/man2/eventfd.2:241 build/C/man2/signalfd.2:293 build/C/man2/timerfd_create.2:334
516 #: build/C/man2/eventfd.2:249 build/C/man2/signalfd.2:296 build/C/man2/timerfd_create.2:337
517 msgid "Could not mount (internal) anonymous inode device."
521 #: build/C/man2/eventfd.2:249 build/C/man2/s390_runtime_instr.2:73 build/C/man2/sigaltstack.2:147 build/C/man2/signalfd.2:296 build/C/man2/timer_create.2:189 build/C/man2/timerfd_create.2:337
527 #: build/C/man2/eventfd.2:253
528 msgid "There was insufficient memory to create a new eventfd file descriptor."
532 #: build/C/man2/eventfd.2:253 build/C/man2/prctl.2:1065 build/C/man3/psignal.3:95 build/C/man2/restart_syscall.2:96 build/C/man2/rt_sigqueueinfo.2:169 build/C/man2/s390_runtime_instr.2:79 build/C/man2/sgetmask.2:66 build/C/man2/signalfd.2:299 build/C/man3/sigqueue.3:112 build/C/man3/sigvec.3:234 build/C/man2/timer_create.2:193 build/C/man2/timer_delete.2:65 build/C/man2/timer_getoverrun.2:95 build/C/man2/timer_settime.2:205 build/C/man2/timerfd_create.2:375 build/C/man2/tkill.2:104
537 #. eventfd() is in glibc 2.7, but reportedly does not build
539 #: build/C/man2/eventfd.2:266
541 "B<eventfd>() is available on Linux since kernel 2.6.22. Working support is "
542 "provided in glibc since version 2.8. The B<eventfd2>() system call (see "
543 "NOTES) is available on Linux since kernel 2.6.27. Since version 2.9, the "
544 "glibc B<eventfd>() wrapper will employ the B<eventfd2>() system call, if "
545 "it is supported by the kernel."
549 #: build/C/man2/eventfd.2:271
550 msgid "B<eventfd>() and B<eventfd2>() are Linux-specific."
554 #: build/C/man2/eventfd.2:279
556 "Applications can use an eventfd file descriptor instead of a pipe (see "
557 "B<pipe>(2)) in all cases where a pipe is used simply to signal events. The "
558 "kernel overhead of an eventfd file descriptor is much lower than that of a "
559 "pipe, and only one file descriptor is required (versus the two required for "
563 #. or eventually syslets/threadlets
565 #: build/C/man2/eventfd.2:285
567 "When used in the kernel, an eventfd file descriptor can provide a bridge "
568 "from kernel to user space, allowing, for example, functionalities like KAIO "
569 "(kernel AIO) to signal to a file descriptor that some operation is "
574 #: build/C/man2/eventfd.2:302
576 "A key point about an eventfd file descriptor is that it can be monitored "
577 "just like any other file descriptor using B<select>(2), B<poll>(2), or "
578 "B<epoll>(7). This means that an application can simultaneously monitor the "
579 "readiness of \"traditional\" files and the readiness of other kernel "
580 "mechanisms that support the eventfd interface. (Without the B<eventfd>() "
581 "interface, these mechanisms could not be multiplexed via B<select>(2), "
582 "B<poll>(2), or B<epoll>(7).)"
586 #: build/C/man2/eventfd.2:302 build/C/man2/signalfd.2:326 build/C/man2/sigwaitinfo.2:183 build/C/man2/timer_create.2:243 build/C/man2/wait.2:525
588 msgid "C library/kernel ABI differences"
592 #: build/C/man2/eventfd.2:316
594 "There are two underlying Linux system calls: B<eventfd>() and the more "
595 "recent B<eventfd2>(). The former system call does not implement a I<flags> "
596 "argument. The latter system call implements the I<flags> values described "
597 "above. The glibc wrapper function will use B<eventfd2>() where it is "
602 #: build/C/man2/eventfd.2:316
604 msgid "Additional glibc features"
608 #: build/C/man2/eventfd.2:320
610 "The GNU C library defines an additional type, and two functions that attempt "
611 "to abstract some of the details of reading and writing on an eventfd file "
616 #: build/C/man2/eventfd.2:324
618 msgid "typedef uint64_t eventfd_t;\n"
622 #: build/C/man2/eventfd.2:327
625 "int eventfd_read(int fd, eventfd_t *value);\n"
626 "int eventfd_write(int fd, eventfd_t value);\n"
630 #: build/C/man2/eventfd.2:334
632 "The functions perform the read and write operations on an eventfd file "
633 "descriptor, returning 0 if the correct number of bytes was transferred, or "
638 #: build/C/man2/eventfd.2:334 build/C/man2/sigaction.2:801 build/C/man2/sigaltstack.2:217 build/C/man2/signalfd.2:360 build/C/man3/sigwait.3:91 build/C/man2/timer_create.2:264 build/C/man2/timer_getoverrun.2:128 build/C/man2/timer_settime.2:209 build/C/man2/timerfd_create.2:386 build/C/man2/wait.2:552
644 #: build/C/man2/eventfd.2:343
646 "The following program creates an eventfd file descriptor and then forks to "
647 "create a child process. While the parent briefly sleeps, the child writes "
648 "each of the integers supplied in the program's command-line arguments to the "
649 "eventfd file descriptor. When the parent has finished sleeping, it reads "
650 "from the eventfd file descriptor."
654 #: build/C/man2/eventfd.2:345
655 msgid "The following shell session shows a sample run of the program:"
659 #: build/C/man2/eventfd.2:357
662 "$B< ./a.out 1 2 4 7 14>\n"
663 "Child writing 1 to efd\n"
664 "Child writing 2 to efd\n"
665 "Child writing 4 to efd\n"
666 "Child writing 7 to efd\n"
667 "Child writing 14 to efd\n"
668 "Child completed write loop\n"
669 "Parent about to read\n"
670 "Parent read 28 (0x1c) from efd\n"
674 #: build/C/man2/eventfd.2:359 build/C/man2/signalfd.2:383 build/C/man2/timer_create.2:295 build/C/man2/timerfd_create.2:414 build/C/man2/wait.2:587
676 msgid "Program source"
680 #: build/C/man2/eventfd.2:367
683 "#include E<lt>sys/eventfd.hE<gt>\n"
684 "#include E<lt>unistd.hE<gt>\n"
685 "#include E<lt>stdlib.hE<gt>\n"
686 "#include E<lt>stdio.hE<gt>\n"
687 "#include E<lt>stdint.hE<gt> /* Definition of uint64_t */\n"
691 #: build/C/man2/eventfd.2:370 build/C/man2/signalfd.2:394
694 "#define handle_error(msg) \\e\n"
695 " do { perror(msg); exit(EXIT_FAILURE); } while (0)\n"
699 #: build/C/man2/eventfd.2:377
703 "main(int argc, char *argv[])\n"
711 #: build/C/man2/eventfd.2:382
714 " if (argc E<lt> 2) {\n"
715 " fprintf(stderr, \"Usage: %s E<lt>numE<gt>...\\en\", argv[0]);\n"
716 " exit(EXIT_FAILURE);\n"
721 #: build/C/man2/eventfd.2:386
724 " efd = eventfd(0, 0);\n"
726 " handle_error(\"eventfd\");\n"
730 #: build/C/man2/eventfd.2:398
733 " switch (fork()) {\n"
735 " for (j = 1; j E<lt> argc; j++) {\n"
736 " printf(\"Child writing %s to efd\\en\", argv[j]);\n"
737 " u = strtoull(argv[j], NULL, 0);\n"
738 " /* strtoull() allows various bases */\n"
739 " s = write(efd, &u, sizeof(uint64_t));\n"
740 " if (s != sizeof(uint64_t))\n"
741 " handle_error(\"write\");\n"
743 " printf(\"Child completed write loop\\en\");\n"
747 #: build/C/man2/eventfd.2:400
749 msgid " exit(EXIT_SUCCESS);\n"
753 #: build/C/man2/eventfd.2:403
761 #: build/C/man2/eventfd.2:411
764 " printf(\"Parent about to read\\en\");\n"
765 " s = read(efd, &u, sizeof(uint64_t));\n"
766 " if (s != sizeof(uint64_t))\n"
767 " handle_error(\"read\");\n"
768 " printf(\"Parent read %llu (0x%llx) from efd\\en\",\n"
769 " (unsigned long long) u, (unsigned long long) u);\n"
770 " exit(EXIT_SUCCESS);\n"
774 #: build/C/man2/eventfd.2:416
778 " handle_error(\"fork\");\n"
784 #: build/C/man2/eventfd.2:428
786 "B<futex>(2), B<pipe>(2), B<poll>(2), B<read>(2), B<select>(2), "
787 "B<signalfd>(2), B<timerfd_create>(2), B<write>(2), B<epoll>(7), "
792 #: build/C/man2/getitimer.2:12
798 #: build/C/man2/getitimer.2:15
799 msgid "getitimer, setitimer - get or set value of an interval timer"
803 #: build/C/man2/getitimer.2:18
805 msgid "B<#include E<lt>sys/time.hE<gt>>\n"
809 #: build/C/man2/getitimer.2:20
811 msgid "B<int getitimer(int >I<which>B<, struct itimerval *>I<curr_value>B<);>\n"
815 #: build/C/man2/getitimer.2:23
818 "B<int setitimer(int >I<which>B<, const struct itimerval *>I<new_value>B<,>\n"
819 "B< struct itimerval *>I<old_value>B<);>\n"
823 #: build/C/man2/getitimer.2:29
825 "The system provides each process with three interval timers, each "
826 "decrementing in a distinct time domain. When a timer expires, a signal is "
827 "sent to the process, and the timer is reset to the specified interval (if "
832 #: build/C/man2/getitimer.2:29
834 msgid "B<ITIMER_REAL>"
838 #: build/C/man2/getitimer.2:34
839 msgid "decrements in real time, and delivers B<SIGALRM> upon expiration."
843 #: build/C/man2/getitimer.2:34
845 msgid "B<ITIMER_VIRTUAL>"
849 #: build/C/man2/getitimer.2:39
851 "decrements only when the process is executing, and delivers B<SIGVTALRM> "
856 #: build/C/man2/getitimer.2:39
858 msgid "B<ITIMER_PROF>"
862 #: build/C/man2/getitimer.2:49
864 "decrements both when the process executes and when the system is executing "
865 "on behalf of the process. Coupled with B<ITIMER_VIRTUAL>, this timer is "
866 "usually used to profile the time spent by the application in user and kernel "
867 "space. B<SIGPROF> is delivered upon expiration."
871 #: build/C/man2/getitimer.2:51
872 msgid "Timer values are defined by the following structures:"
876 #: build/C/man2/getitimer.2:59
879 "struct itimerval {\n"
880 " struct timeval it_interval; /* Interval for periodic timer */\n"
881 " struct timeval it_value; /* Time until next expiration */\n"
886 #: build/C/man2/getitimer.2:64
890 " time_t tv_sec; /* seconds */\n"
891 " suseconds_t tv_usec; /* microseconds */\n"
896 #: build/C/man2/getitimer.2:90
898 "The function B<getitimer>() fills the structure pointed to by I<curr_value> "
899 "with the current value (i.e., the amount of time remaining until the next "
900 "expiration) of the timer specified by I<which> (one of B<ITIMER_REAL>, "
901 "B<ITIMER_VIRTUAL>, or B<ITIMER_PROF>). The subfields of the field "
902 "I<it_value> are set to the amount of time remaining on the timer, or zero if "
903 "the timer is disabled. The I<it_interval> field is set to the timer "
904 "interval (period); a value of zero returned in (both subfields of) this "
905 "field indicates that this is a single-shot timer."
909 #: build/C/man2/getitimer.2:101
911 "The function B<setitimer>() sets the specified timer to the value in "
912 "I<new_value>. If I<old_value> is non-NULL, the old value of the timer "
913 "(i.e., the same information as returned by B<getitimer>()) is stored there."
917 #: build/C/man2/getitimer.2:111
919 "Timers decrement from I<it_value> to zero, generate a signal, and reset to "
920 "I<it_interval>. A timer which is set to zero (I<it_value> is zero or the "
921 "timer expires and I<it_interval> is zero) stops."
925 #: build/C/man2/getitimer.2:117
927 "Both I<tv_sec> and I<tv_usec> are significant in determining the duration of "
932 #: build/C/man2/getitimer.2:129
934 "Timers will never expire before the requested time, but may expire some "
935 "(short) time afterward, which depends on the system timer resolution and on "
936 "the system load; see B<time>(7). (But see BUGS below.) Upon expiration, a "
937 "signal will be generated and the timer reset. If the timer expires while "
938 "the process is active (always true for B<ITIMER_VIRTUAL>), the signal will "
939 "be delivered immediately when generated. Otherwise, the delivery will be "
940 "offset by a small time dependent on the system loading."
944 #: build/C/man2/getitimer.2:134 build/C/man2/killpg.2:94 build/C/man2/tkill.2:92
946 "On success, zero is returned. On error, -1 is returned, and I<errno> is set "
951 #: build/C/man2/getitimer.2:135 build/C/man2/prctl.2:825 build/C/man2/sigaction.2:677 build/C/man2/sigaltstack.2:138 build/C/man2/sigpending.2:60 build/C/man2/sigprocmask.2:100 build/C/man2/sigsuspend.2:77 build/C/man2/timer_settime.2:184 build/C/man2/timerfd_create.2:349
957 #: build/C/man2/getitimer.2:142 build/C/man2/timerfd_create.2:356
958 msgid "I<new_value>, I<old_value>, or I<curr_value> is not valid a pointer."
962 #: build/C/man2/getitimer.2:155
964 "I<which> is not one of B<ITIMER_REAL>, B<ITIMER_VIRTUAL>, or B<ITIMER_PROF>; "
965 "or (since Linux 2.6.22) one of the I<tv_usec> fields in the structure "
966 "pointed to by I<new_value> contains a value outside the range 0 to 999999."
970 #: build/C/man2/getitimer.2:165
972 "POSIX.1-2001, SVr4, 4.4BSD (this call first appeared in 4.2BSD). "
973 "POSIX.1-2008 marks B<getitimer>() and B<setitimer>() obsolete, "
974 "recommending the use of the POSIX timers API (B<timer_gettime>(2), "
975 "B<timer_settime>(2), etc.) instead."
979 #: build/C/man2/getitimer.2:171
981 "A child created via B<fork>(2) does not inherit its parent's interval "
982 "timers. Interval timers are preserved across an B<execve>(2)."
986 #: build/C/man2/getitimer.2:181
988 "POSIX.1 leaves the interaction between B<setitimer>() and the three "
989 "interfaces B<alarm>(2), B<sleep>(3), and B<usleep>(3) unspecified."
993 #: build/C/man2/getitimer.2:183
994 msgid "The standards are silent on the meaning of the call:"
998 #: build/C/man2/getitimer.2:185
1000 msgid " setitimer(which, NULL, &old_value);\n"
1004 #: build/C/man2/getitimer.2:188
1006 "Many systems (Solaris, the BSDs, and perhaps others) treat this as "
1011 #: build/C/man2/getitimer.2:190
1013 msgid " getitimer(which, &old_value);\n"
1017 #: build/C/man2/getitimer.2:196
1019 "In Linux, this is treated as being equivalent to a call in which the "
1020 "I<new_value> fields are zero; that is, the timer is disabled. I<Don't use "
1021 "this Linux misfeature>: it is nonportable and unnecessary."
1025 #: build/C/man2/getitimer.2:196 build/C/man2/kill.2:161 build/C/man3/profil.3:72 build/C/man3/psignal.3:101 build/C/man2/sigaction.2:792 build/C/man2/signalfd.2:352 build/C/man2/sigpending.2:85 build/C/man3/sigset.3:232 build/C/man2/timer_getoverrun.2:115 build/C/man2/timerfd_create.2:380 build/C/man2/wait.2:537
1031 #: build/C/man2/getitimer.2:205
1033 "The generation and delivery of a signal are distinct, and only one instance "
1034 "of each of the signals listed above may be pending for a process. Under "
1035 "very heavy loading, an B<ITIMER_REAL> timer may expire before the signal "
1036 "from a previous expiration has been delivered. The second signal in such an "
1037 "event will be lost."
1041 #: build/C/man2/getitimer.2:220
1043 "On Linux kernels before 2.6.16, timer values are represented in jiffies. If "
1044 "a request is made set a timer with a value whose jiffies representation "
1045 "exceeds B<MAX_SEC_IN_JIFFIES> (defined in I<include/linux/jiffies.h>), then "
1046 "the timer is silently truncated to this ceiling value. On Linux/i386 "
1047 "(where, since Linux 2.6.13, the default jiffy is 0.004 seconds), this means "
1048 "that the ceiling value for a timer is approximately 99.42 days. Since Linux "
1049 "2.6.16, the kernel uses a different internal representation for times, and "
1050 "this ceiling is removed."
1053 #. 4 Jul 2005: It looks like this bug may remain in 2.4.x.
1054 #. http://lkml.org/lkml/2005/7/1/165
1056 #: build/C/man2/getitimer.2:227
1058 "On certain systems (including i386), Linux kernels before version 2.6.12 "
1059 "have a bug which will produce premature timer expirations of up to one jiffy "
1060 "under some circumstances. This bug is fixed in kernel 2.6.12."
1063 #. Bugzilla report 25 Apr 2006:
1064 #. http://bugzilla.kernel.org/show_bug.cgi?id=6443
1065 #. "setitimer() should reject noncanonical arguments"
1067 #: build/C/man2/getitimer.2:246
1069 "POSIX.1-2001 says that B<setitimer>() should fail if a I<tv_usec> value is "
1070 "specified that is outside of the range 0 to 999999. However, in kernels up "
1071 "to and including 2.6.21, Linux does not give an error, but instead silently "
1072 "adjusts the corresponding seconds value for the timer. From kernel 2.6.22 "
1073 "onward, this nonconformance has been repaired: an improper I<tv_usec> value "
1074 "results in an B<EINVAL> error."
1078 #: build/C/man2/getitimer.2:253
1080 "B<gettimeofday>(2), B<sigaction>(2), B<signal>(2), B<timer_create>(2), "
1081 "B<timerfd_create>(2), B<time>(7)"
1085 #: build/C/man3/gsignal.3:27
1091 #: build/C/man3/gsignal.3:27
1097 #: build/C/man3/gsignal.3:30
1098 msgid "gsignal, ssignal - software signal facility"
1102 #: build/C/man3/gsignal.3:33 build/C/man2/kill.2:52 build/C/man3/psignal.3:36 build/C/man3/raise.3:35 build/C/man2/sigaction.2:53 build/C/man3/siginterrupt.3:37 build/C/man3/sigpause.3:31 build/C/man3/sigwait.3:32 build/C/man2/sigwaitinfo.2:31
1104 msgid "B<#include E<lt>signal.hE<gt>>\n"
1108 #: build/C/man3/gsignal.3:35
1110 msgid "B<typedef void (*sighandler_t)(int);>\n"
1114 #: build/C/man3/gsignal.3:37
1116 msgid "B<int gsignal(int >I<signum>B<);>\n"
1120 #: build/C/man3/gsignal.3:39
1122 msgid "B<sighandler_t ssignal(int >I<signum>B<, sighandler_t >I<action>B<);>\n"
1126 #: build/C/man3/gsignal.3:44 build/C/man2/kill.2:59 build/C/man2/killpg.2:53 build/C/man3/profil.3:42 build/C/man3/psignal.3:46 build/C/man2/sigaction.2:61 build/C/man2/sigaltstack.2:38 build/C/man3/siginterrupt.3:44 build/C/man2/sigpending.2:40 build/C/man2/sigprocmask.2:41 build/C/man3/sigqueue.3:39 build/C/man3/sigset.3:45 build/C/man3/sigsetops.3:51 build/C/man2/sigsuspend.2:40 build/C/man3/sigvec.3:45 build/C/man3/sigwait.3:39 build/C/man2/sigwaitinfo.2:41 build/C/man2/timer_create.2:50 build/C/man2/timer_delete.2:41 build/C/man2/timer_getoverrun.2:41 build/C/man2/timer_settime.2:45 build/C/man2/wait.2:69 build/C/man2/wait4.2:53
1127 msgid "Feature Test Macro Requirements for glibc (see B<feature_test_macros>(7)):"
1131 #: build/C/man3/gsignal.3:49
1132 msgid "B<gsignal>(), B<ssignal>(): _SVID_SOURCE"
1136 #: build/C/man3/gsignal.3:57
1138 "Don't use these functions under Linux. Due to a historical mistake, under "
1139 "Linux these functions are aliases for B<raise>(3) and B<signal>(2), "
1144 #: build/C/man3/gsignal.3:95
1146 "Elsewhere, on System V-like systems, these functions implement software "
1147 "signaling, entirely independent of the classical B<signal>(2) and "
1148 "B<kill>(2) functions. The function B<ssignal>() defines the action to "
1149 "take when the software signal with number I<signum> is raised using the "
1150 "function B<gsignal>(), and returns the previous such action or B<SIG_DFL>. "
1151 "The function B<gsignal>() does the following: if no action (or the action "
1152 "B<SIG_DFL>) was specified for I<signum>, then it does nothing and returns "
1153 "0. If the action B<SIG_IGN> was specified for I<signum>, then it does "
1154 "nothing and returns 1. Otherwise, it resets the action to B<SIG_DFL> and "
1155 "calls the action function with argument I<signum>, and returns the value "
1156 "returned by that function. The range of possible values I<signum> varies "
1157 "(often 1-15 or 1-17)."
1161 #: build/C/man3/gsignal.3:103
1163 "These functions are available under AIX, DG/UX, HP-UX, SCO, Solaris, Tru64. "
1164 "They are called obsolete under most of these systems, and are broken under "
1165 "Linux libc and glibc. Some systems also have B<gsignal_r>() and "
1170 #: build/C/man3/gsignal.3:107
1171 msgid "B<kill>(2), B<signal>(2), B<raise>(3)"
1175 #: build/C/man2/kill.2:44
1181 #: build/C/man2/kill.2:44
1187 #: build/C/man2/kill.2:47
1188 msgid "kill - send signal to a process"
1192 #: build/C/man2/kill.2:50
1194 msgid "B<#include E<lt>sys/types.hE<gt>>\n"
1198 #: build/C/man2/kill.2:54
1200 msgid "B<int kill(pid_t >I<pid>B<, int >I<sig>B<);>\n"
1204 #: build/C/man2/kill.2:64
1205 msgid "B<kill>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE"
1209 #: build/C/man2/kill.2:70
1211 "The B<kill>() system call can be used to send any signal to any process "
1216 #: build/C/man2/kill.2:73
1218 "If I<pid> is positive, then signal I<sig> is sent to the process with the ID "
1219 "specified by I<pid>."
1223 #: build/C/man2/kill.2:76
1225 "If I<pid> equals 0, then I<sig> is sent to every process in the process "
1226 "group of the calling process."
1230 #: build/C/man2/kill.2:80
1232 "If I<pid> equals -1, then I<sig> is sent to every process for which the "
1233 "calling process has permission to send signals, except for process 1 "
1234 "(I<init>), but see below."
1238 #: build/C/man2/kill.2:83
1240 "If I<pid> is less than -1, then I<sig> is sent to every process in the "
1241 "process group whose ID is I<-pid>."
1245 #: build/C/man2/kill.2:88
1247 "If I<sig> is 0, then no signal is sent, but error checking is still "
1248 "performed; this can be used to check for the existence of a process ID or "
1253 #: build/C/man2/kill.2:100
1255 "For a process to have permission to send a signal it must either be "
1256 "privileged (under Linux: have the B<CAP_KILL> capability), or the real or "
1257 "effective user ID of the sending process must equal the real or saved "
1258 "set-user-ID of the target process. In the case of B<SIGCONT> it suffices "
1259 "when the sending and receiving processes belong to the same session. "
1260 "(Historically, the rules were different; see NOTES.)"
1264 #: build/C/man2/kill.2:105
1266 "On success (at least one signal was sent), zero is returned. On error, -1 "
1267 "is returned, and I<errno> is set appropriately."
1271 #: build/C/man2/kill.2:109
1272 msgid "An invalid signal was specified."
1276 #: build/C/man2/kill.2:109 build/C/man2/killpg.2:99 build/C/man2/prctl.2:987 build/C/man2/prctl.2:999 build/C/man2/prctl.2:1009 build/C/man2/prctl.2:1017 build/C/man2/rt_sigqueueinfo.2:148 build/C/man2/sigaltstack.2:153 build/C/man3/sigqueue.3:102 build/C/man2/tkill.2:96
1282 #: build/C/man2/kill.2:113 build/C/man2/killpg.2:103
1284 "The process does not have permission to send the signal to any of the target "
1289 #: build/C/man2/kill.2:113 build/C/man2/killpg.2:103 build/C/man2/killpg.2:107 build/C/man2/rt_sigqueueinfo.2:156 build/C/man3/sigqueue.3:108 build/C/man2/tkill.2:101
1295 #: build/C/man2/kill.2:121
1297 "The pid or process group does not exist. Note that an existing process "
1298 "might be a zombie, a process which already committed termination, but has "
1299 "not yet been B<wait>(2)ed for."
1303 #: build/C/man2/kill.2:123 build/C/man2/pause.2:59 build/C/man2/wait.2:425
1304 msgid "SVr4, 4.3BSD, POSIX.1-2001."
1308 #: build/C/man2/kill.2:131
1310 "The only signals that can be sent to process ID 1, the I<init> process, are "
1311 "those for which I<init> has explicitly installed signal handlers. This is "
1312 "done to assure the system is not brought down accidentally."
1316 #: build/C/man2/kill.2:137
1318 "POSIX.1-2001 requires that I<kill(-1,sig)> send I<sig> to all processes that "
1319 "the calling process may send signals to, except possibly for some "
1320 "implementation-defined system processes. Linux allows a process to signal "
1321 "itself, but on Linux the call I<kill(-1,sig)> does not signal the calling "
1326 #: build/C/man2/kill.2:147
1328 "POSIX.1-2001 requires that if a process sends a signal to itself, and the "
1329 "sending thread does not have the signal blocked, and no other thread has it "
1330 "unblocked or is waiting for it in B<sigwait>(3), at least one unblocked "
1331 "signal must be delivered to the sending thread before the B<kill>() "
1336 #: build/C/man2/kill.2:147 build/C/man3/sigpause.3:82 build/C/man2/wait.2:480
1341 #. In the 0.* kernels things chopped and changed quite
1342 #. a bit - MTK, 24 Jul 02
1344 #: build/C/man2/kill.2:161
1346 "Across different kernel versions, Linux has enforced different rules for the "
1347 "permissions required for an unprivileged process to send a signal to another "
1348 "process. In kernels 1.0 to 1.2.2, a signal could be sent if the effective "
1349 "user ID of the sender matched effective user ID of the target, or the real "
1350 "user ID of the sender matched the real user ID of the target. From kernel "
1351 "1.2.3 until 1.3.77, a signal could be sent if the effective user ID of the "
1352 "sender matched either the real or effective user ID of the target. The "
1353 "current rules, which conform to POSIX.1-2001, were adopted in kernel 1.3.78."
1357 #: build/C/man2/kill.2:171
1359 "In 2.6 kernels up to and including 2.6.7, there was a bug that meant that "
1360 "when sending signals to a process group, B<kill>() failed with the error "
1361 "B<EPERM> if the caller did not have permission to send the signal to I<any> "
1362 "(rather than I<all>) of the members of the process group. Notwithstanding "
1363 "this error return, the signal was still delivered to all of the processes "
1364 "for which the caller had permission to signal."
1368 #: build/C/man2/kill.2:181
1370 "B<_exit>(2), B<killpg>(2), B<signal>(2), B<tkill>(2), B<exit>(3), "
1371 "B<sigqueue>(3), B<capabilities>(7), B<credentials>(7), B<signal>(7)"
1375 #: build/C/man2/killpg.2:42
1381 #: build/C/man2/killpg.2:42 build/C/man3/sigset.3:26
1387 #: build/C/man2/killpg.2:45
1388 msgid "killpg - send signal to a process group"
1392 #: build/C/man2/killpg.2:49
1393 msgid "B<int killpg(int >I<pgrp>B<, int >I<sig>B<);>"
1397 #: build/C/man2/killpg.2:55
1399 msgid "B<killpg>():"
1403 #: build/C/man2/killpg.2:59 build/C/man2/sigaltstack.2:46 build/C/man3/siginterrupt.3:51 build/C/man2/wait4.2:60
1405 "_BSD_SOURCE || _XOPEN_SOURCE\\ E<gt>=\\ 500 || _XOPEN_SOURCE\\ &&\\ "
1406 "_XOPEN_SOURCE_EXTENDED"
1410 #: build/C/man2/killpg.2:69
1412 "B<killpg>() sends the signal I<sig> to the process group I<pgrp>. See "
1413 "B<signal>(7) for a list of signals."
1417 #: build/C/man2/killpg.2:78
1419 "If I<pgrp> is 0, B<killpg>() sends the signal to the calling process's "
1420 "process group. (POSIX says: If I<pgrp> is less than or equal to 1, the "
1421 "behavior is undefined.)"
1425 #: build/C/man2/killpg.2:89
1427 "For a process to have permission to send a signal it must either be "
1428 "privileged (under Linux: have the B<CAP_KILL> capability), or the real or "
1429 "effective user ID of the sending process must equal the real or saved "
1430 "set-user-ID of the target process. In the case of B<SIGCONT> it suffices "
1431 "when the sending and receiving processes belong to the same session."
1435 #: build/C/man2/killpg.2:99
1436 msgid "I<sig> is not a valid signal number."
1440 #: build/C/man2/killpg.2:107
1441 msgid "No process can be found in the process group specified by I<pgrp>."
1445 #: build/C/man2/killpg.2:111
1447 "The process group was given as 0 but the sending process does not have a "
1452 #: build/C/man2/killpg.2:115
1454 "SVr4, 4.4BSD (the B<killpg>() function call first appeared in 4BSD), "
1459 #: build/C/man2/killpg.2:129
1461 "There are various differences between the permission checking in BSD-type "
1462 "systems and System\\ V-type systems. See the POSIX rationale for "
1463 "B<kill>(). A difference not mentioned by POSIX concerns the return value "
1464 "B<EPERM>: BSD documents that no signal is sent and B<EPERM> returned when "
1465 "the permission check failed for at least one target process, while POSIX "
1466 "documents B<EPERM> only when the permission check failed for all target "
1471 #: build/C/man2/killpg.2:134
1473 "On Linux, B<killpg>() is implemented as a library function that makes the "
1474 "call I<kill(-pgrp,\\ sig)>."
1478 #: build/C/man2/killpg.2:140
1480 "B<getpgrp>(2), B<kill>(2), B<signal>(2), B<capabilities>(7), "
1485 #: build/C/man2/pause.2:30
1491 #: build/C/man2/pause.2:30
1497 #: build/C/man2/pause.2:33
1498 msgid "pause - wait for signal"
1502 #: build/C/man2/pause.2:35
1503 msgid "B<#include E<lt>unistd.hE<gt>>"
1507 #: build/C/man2/pause.2:37
1508 msgid "B<int pause(void);>"
1512 #: build/C/man2/pause.2:42
1514 "B<pause>() causes the calling process (or thread) to sleep until a signal "
1515 "is delivered that either terminates the process or causes the invocation of "
1516 "a signal-catching function."
1519 #. .BR ERESTARTNOHAND .
1521 #: build/C/man2/pause.2:53
1523 "B<pause>() returns only when a signal was caught and the signal-catching "
1524 "function returned. In this case, B<pause>() returns -1, and I<errno> is "
1529 #: build/C/man2/pause.2:54 build/C/man2/sigsuspend.2:81 build/C/man2/sigwaitinfo.2:123 build/C/man2/wait.2:411
1535 #: build/C/man2/pause.2:57
1536 msgid "a signal was caught and the signal-catching function returned."
1540 #: build/C/man2/pause.2:64
1541 msgid "B<kill>(2), B<select>(2), B<signal>(2), B<sigsuspend>(2)"
1545 #: build/C/man2/prctl.2:52
1551 #: build/C/man2/prctl.2:52 build/C/man2/restart_syscall.2:33 build/C/man2/sgetmask.2:26 build/C/man2/sigaction.2:47 build/C/man7/signal.7:46 build/C/man2/sigreturn.2:30 build/C/man3/sigvec.3:26 build/C/man2/tkill.2:29
1557 #: build/C/man2/prctl.2:55
1558 msgid "prctl - operations on a process"
1562 #: build/C/man2/prctl.2:58
1564 msgid "B<#include E<lt>sys/prctl.hE<gt>>\n"
1568 #: build/C/man2/prctl.2:61
1571 "B<int prctl(int >I<option>B<, unsigned long >I<arg2>B<, unsigned long "
1573 "B< unsigned long >I<arg4>B<, unsigned long >I<arg5>B<);>\n"
1577 #: build/C/man2/prctl.2:68
1579 "B<prctl>() is called with a first argument describing what to do (with "
1580 "values defined in I<E<lt>linux/prctl.hE<gt>>), and further arguments with a "
1581 "significance depending on the first one. The first argument can be:"
1585 #: build/C/man2/prctl.2:68
1587 msgid "B<PR_CAPBSET_READ> (since Linux 2.6.25)"
1591 #: build/C/man2/prctl.2:80
1593 "Return (as the function result) 1 if the capability specified in I<arg2> is "
1594 "in the calling thread's capability bounding set, or 0 if it is not. (The "
1595 "capability constants are defined in I<E<lt>linux/capability.hE<gt>>.) The "
1596 "capability bounding set dictates whether the process can receive the "
1597 "capability through a file's permitted capability set on a subsequent call to "
1602 #: build/C/man2/prctl.2:85
1604 "If the capability specified in I<arg2> is not valid, then the call fails "
1605 "with the error B<EINVAL>."
1609 #: build/C/man2/prctl.2:85
1611 msgid "B<PR_CAPBSET_DROP> (since Linux 2.6.25)"
1615 #: build/C/man2/prctl.2:94
1617 "If the calling thread has the B<CAP_SETPCAP> capability, then drop the "
1618 "capability specified by I<arg2> from the calling thread's capability "
1619 "bounding set. Any children of the calling thread will inherit the newly "
1620 "reduced bounding set."
1624 #: build/C/man2/prctl.2:106
1626 "The call fails with the error: B<EPERM> if the calling thread does not have "
1627 "the B<CAP_SETPCAP>; B<EINVAL> if I<arg2> does not represent a valid "
1628 "capability; or B<EINVAL> if file capabilities are not enabled in the kernel, "
1629 "in which case bounding sets are not supported."
1633 #: build/C/man2/prctl.2:106
1635 msgid "B<PR_SET_CHILD_SUBREAPER> (since Linux 3.4)"
1638 #. commit ebec18a6d3aa1e7d84aab16225e87fd25170ec2b
1640 #: build/C/man2/prctl.2:131
1642 "If I<arg2> is nonzero, set the \"child subreaper\" attribute of the calling "
1643 "process; if I<arg2> is zero, unset the attribute. When a process is marked "
1644 "as a child subreaper, all of the children that it creates, and their "
1645 "descendants, will be marked as having a subreaper. In effect, a subreaper "
1646 "fulfills the role of B<init>(1) for its descendant processes. Upon "
1647 "termination of a process that is orphaned (i.e., its immediate parent has "
1648 "already terminated) and marked as having a subreaper, the nearest still "
1649 "living ancestor subreaper will receive a B<SIGCHLD> signal and be able to "
1650 "B<wait>(2) on the process to discover its termination status."
1654 #: build/C/man2/prctl.2:131
1656 msgid "B<PR_GET_CHILD_SUBREAPER> (since Linux 3.4)"
1660 #: build/C/man2/prctl.2:136
1662 "Return the \"child subreaper\" setting of the caller, in the location "
1663 "pointed to by I<(int\\ *) arg2>."
1667 #: build/C/man2/prctl.2:136
1669 msgid "B<PR_SET_DUMPABLE> (since Linux 2.3.20)"
1672 #. See http://marc.theaimsgroup.com/?l=linux-kernel&m=115270289030630&w=2
1673 #. Subject: Fix prctl privilege escalation (CVE-2006-2451)
1674 #. From: Marcel Holtmann <marcel () holtmann ! org>
1675 #. Date: 2006-07-12 11:12:00
1677 #: build/C/man2/prctl.2:162
1679 "Set the state of the flag determining whether core dumps are produced for "
1680 "the calling process upon delivery of a signal whose default behavior is to "
1681 "produce a core dump. (Normally, this flag is set for a process by default, "
1682 "but it is cleared when a set-user-ID or set-group-ID program is executed and "
1683 "also by various system calls that manipulate process UIDs and GIDs). In "
1684 "kernels up to and including 2.6.12, I<arg2> must be either 0 (process is not "
1685 "dumpable) or 1 (process is dumpable). Between kernels 2.6.13 and 2.6.17, "
1686 "the value 2 was also permitted, which caused any binary which normally would "
1687 "not be dumped to be dumped readable by root only; for security reasons, this "
1688 "feature has been removed. (See also the description of "
1689 "I</proc/sys/fs/suid_dumpable> in B<proc>(5).) Processes that are not "
1690 "dumpable can not be attached via B<ptrace>(2) B<PTRACE_ATTACH>."
1694 #: build/C/man2/prctl.2:162
1696 msgid "B<PR_GET_DUMPABLE> (since Linux 2.3.20)"
1699 #. Since Linux 2.6.13, the dumpable flag can have the value 2,
1700 #. but in 2.6.13 PR_GET_DUMPABLE simply returns 1 if the dumpable
1701 #. flags has a nonzero value. This was fixed in 2.6.14.
1703 #: build/C/man2/prctl.2:169
1705 "Return (as the function result) the current state of the calling process's "
1710 #: build/C/man2/prctl.2:169
1712 msgid "B<PR_SET_ENDIAN> (since Linux 2.6.18, PowerPC only)"
1715 #. Respectively 0, 1, 2
1717 #: build/C/man2/prctl.2:179
1719 "Set the endian-ness of the calling process to the value given in I<arg2>, "
1720 "which should be one of the following: B<PR_ENDIAN_BIG>, B<PR_ENDIAN_LITTLE>, "
1721 "or B<PR_ENDIAN_PPC_LITTLE> (PowerPC pseudo little endian)."
1725 #: build/C/man2/prctl.2:179
1727 msgid "B<PR_GET_ENDIAN> (since Linux 2.6.18, PowerPC only)"
1731 #: build/C/man2/prctl.2:184
1733 "Return the endian-ness of the calling process, in the location pointed to by "
1734 "I<(int\\ *) arg2>."
1738 #: build/C/man2/prctl.2:184
1740 msgid "B<PR_SET_FPEMU> (since Linux 2.4.18, 2.5.9, only on ia64)"
1744 #: build/C/man2/prctl.2:191
1746 "Set floating-point emulation control bits to I<arg2>. Pass "
1747 "B<PR_FPEMU_NOPRINT> to silently emulate fp operations accesses, or "
1748 "B<PR_FPEMU_SIGFPE> to not emulate fp operations and send B<SIGFPE> instead."
1752 #: build/C/man2/prctl.2:191
1754 msgid "B<PR_GET_FPEMU> (since Linux 2.4.18, 2.5.9, only on ia64)"
1758 #: build/C/man2/prctl.2:196
1760 "Return floating-point emulation control bits, in the location pointed to by "
1761 "I<(int\\ *) arg2>."
1765 #: build/C/man2/prctl.2:196
1767 msgid "B<PR_SET_FPEXC> (since Linux 2.4.21, 2.5.32, only on PowerPC)"
1771 #: build/C/man2/prctl.2:209
1773 "Set floating-point exception mode to I<arg2>. Pass B<PR_FP_EXC_SW_ENABLE> "
1774 "to use FPEXC for FP exception enables, B<PR_FP_EXC_DIV> for floating-point "
1775 "divide by zero, B<PR_FP_EXC_OVF> for floating-point overflow, "
1776 "B<PR_FP_EXC_UND> for floating-point underflow, B<PR_FP_EXC_RES> for "
1777 "floating-point inexact result, B<PR_FP_EXC_INV> for floating-point invalid "
1778 "operation, B<PR_FP_EXC_DISABLED> for FP exceptions disabled, "
1779 "B<PR_FP_EXC_NONRECOV> for async nonrecoverable exception mode, "
1780 "B<PR_FP_EXC_ASYNC> for async recoverable exception mode, "
1781 "B<PR_FP_EXC_PRECISE> for precise exception mode."
1785 #: build/C/man2/prctl.2:209
1787 msgid "B<PR_GET_FPEXC> (since Linux 2.4.21, 2.5.32, only on PowerPC)"
1791 #: build/C/man2/prctl.2:214
1793 "Return floating-point exception mode, in the location pointed to by I<(int\\ "
1798 #: build/C/man2/prctl.2:214
1800 msgid "B<PR_SET_KEEPCAPS> (since Linux 2.2.18)"
1804 #: build/C/man2/prctl.2:232
1806 "Set the state of the thread's \"keep capabilities\" flag, which determines "
1807 "whether the threads's permitted capability set is cleared when a change is "
1808 "made to the threads's user IDs such that the threads's real UID, effective "
1809 "UID, and saved set-user-ID all become nonzero when at least one of them "
1810 "previously had the value 0. By default, the permitted capability set is "
1811 "cleared when such a change is made; setting the \"keep capabilities\" flag "
1812 "prevents it from being cleared. I<arg2> must be either 0 (permitted "
1813 "capabilities are cleared) or 1 (permitted capabilities are kept). (A "
1814 "thread's I<effective> capability set is always cleared when such a "
1815 "credential change is made, regardless of the setting of the \"keep "
1816 "capabilities\" flag.) The \"keep capabilities\" value will be reset to 0 on "
1817 "subsequent calls to B<execve>(2)."
1821 #: build/C/man2/prctl.2:232
1823 msgid "B<PR_GET_KEEPCAPS> (since Linux 2.2.18)"
1827 #: build/C/man2/prctl.2:236
1829 "Return (as the function result) the current state of the calling threads's "
1830 "\"keep capabilities\" flag."
1834 #: build/C/man2/prctl.2:236
1836 msgid "B<PR_SET_NAME> (since Linux 2.6.9)"
1839 #. TASK_COMM_LEN in include/linux/sched.h
1841 #: build/C/man2/prctl.2:255
1843 "Set the name of the calling thread, using the value in the location pointed "
1844 "to by I<(char\\ *) arg2>. The name can be up to 16 bytes long, including "
1845 "the terminating null byte. (If the length of the string, including the "
1846 "terminating null byte, exceeds 16 bytes, the string is silently truncated.) "
1847 "This is the same attribute that can be set via B<pthread_setname_np>(3) and "
1848 "retrieved using B<pthread_getname_np>(3). The attribute is likewise "
1849 "accessible via I</proc/self/task/[tid]/comm>, where I<tid> is the name of "
1850 "the calling thread."
1854 #: build/C/man2/prctl.2:255
1856 msgid "B<PR_GET_NAME> (since Linux 2.6.11)"
1860 #: build/C/man2/prctl.2:262
1862 "Return the name of the calling thread, in the buffer pointed to by I<(char\\ "
1863 "*) arg2>. The buffer should allow space for up to 16 bytes; the returned "
1864 "string will be null-terminated."
1868 #: build/C/man2/prctl.2:262
1870 msgid "B<PR_SET_NO_NEW_PRIVS> (since Linux 3.5)"
1874 #: build/C/man2/prctl.2:285
1876 "Set the calling process's I<no_new_privs> bit to the value in I<arg2>. With "
1877 "I<no_new_privs> set to 1, B<execve>(2) promises not to grant privileges to "
1878 "do anything that could not have been done without the B<execve>(2) call "
1879 "(for example, rendering the set-user-ID and set-group-ID permission bits, "
1880 "and file capabilities non-functional). Once set, this bit cannot be unset. "
1881 "The setting of this bit is inherited by children created by B<fork>(2) and "
1882 "B<clone>(2), and preserved across B<execve>(2)."
1886 #: build/C/man2/prctl.2:288
1888 "For more information, see the kernel source file "
1889 "I<Documentation/prctl/no_new_privs.txt>."
1893 #: build/C/man2/prctl.2:288
1895 msgid "B<PR_GET_NO_NEW_PRIVS> (since Linux 3.5)"
1899 #: build/C/man2/prctl.2:299
1901 "Return (as the function result) the value of the I<no_new_privs> bit for the "
1902 "current process. A value of 0 indicates the regular B<execve>(2) "
1903 "behavior. A value of 1 indicates B<execve>(2) will operate in the "
1904 "privilege-restricting mode described above."
1908 #: build/C/man2/prctl.2:299
1910 msgid "B<PR_SET_PDEATHSIG> (since Linux 2.1.57)"
1914 #: build/C/man2/prctl.2:312
1916 "Set the parent process death signal of the calling process to I<arg2> "
1917 "(either a signal value in the range 1..maxsig, or 0 to clear). This is the "
1918 "signal that the calling process will get when its parent dies. This value "
1919 "is cleared for the child of a B<fork>(2) and (since Linux 2.4.36 / 2.6.23) "
1920 "when executing a set-user-ID or set-group-ID binary. This value is "
1921 "preserved across B<execve>(2)."
1925 #: build/C/man2/prctl.2:312
1927 msgid "B<PR_GET_PDEATHSIG> (since Linux 2.3.15)"
1931 #: build/C/man2/prctl.2:317
1933 "Return the current value of the parent process death signal, in the location "
1934 "pointed to by I<(int\\ *) arg2>."
1938 #: build/C/man2/prctl.2:317
1940 msgid "B<PR_SET_PTRACER> (since Linux 3.4)"
1943 #. commit 2d514487faf188938a4ee4fb3464eeecfbdcf8eb
1944 #. commit bf06189e4d14641c0148bea16e9dd24943862215
1946 #: build/C/man2/prctl.2:342
1948 "This is meaningful only when the Yama LSM is enabled and in mode 1 "
1949 "(\"restricted ptrace\", visible via I</proc/sys/kernel/yama/ptrace_scope>). "
1950 "When a \"ptracer process ID\" is passed in I<arg2>, the caller is declaring "
1951 "that the ptracer process can B<ptrace>(2) the calling process as if it were "
1952 "a direct process ancestor. Each B<PR_SET_PTRACER> operation replaces the "
1953 "previous \"ptracer process ID\". Employing B<PR_SET_PTRACER> with I<arg2> "
1954 "set to 0 clears the caller's \"ptracer process ID\". If I<arg2> is "
1955 "B<PR_SET_PTRACER_ANY>, the ptrace restrictions introduced by Yama are "
1956 "effectively disabled for the calling process."
1960 #: build/C/man2/prctl.2:345
1962 "For further information, see the kernel source file "
1963 "I<Documentation/security/Yama.txt>."
1967 #: build/C/man2/prctl.2:345
1969 msgid "B<PR_SET_SECCOMP> (since Linux 2.6.23)"
1972 #. See http://thread.gmane.org/gmane.linux.kernel/542632
1973 #. [PATCH 0 of 2] seccomp updates
1974 #. andrea@cpushare.com
1976 #: build/C/man2/prctl.2:356
1978 "Set the secure computing (seccomp) mode for the calling thread, to limit the "
1979 "available system calls. The seccomp mode is selected via I<arg2>. (The "
1980 "seccomp constants are defined in I<E<lt>linux/seccomp.hE<gt>>.)"
1984 #: build/C/man2/prctl.2:377
1986 "With I<arg2> set to B<SECCOMP_MODE_STRICT> the only system calls that the "
1987 "thread is permitted to make are B<read>(2), B<write>(2), B<_exit>(2), and "
1988 "B<sigreturn>(2). Other system calls result in the delivery of a B<SIGKILL> "
1989 "signal. Strict secure computing mode is useful for number-crunching "
1990 "applications that may need to execute untrusted byte code, perhaps obtained "
1991 "by reading from a pipe or socket. This operation is available only if the "
1992 "kernel is configured with B<CONFIG_SECCOMP> enabled."
1996 #: build/C/man2/prctl.2:392
1998 "With I<arg2> set to B<SECCOMP_MODE_FILTER> (since Linux 3.5) the system "
1999 "calls allowed are defined by a pointer to a Berkeley Packet Filter passed in "
2000 "I<arg3>. This argument is a pointer to I<struct sock_fprog>; it can be "
2001 "designed to filter arbitrary system calls and system call arguments. This "
2002 "mode is available only if the kernel is configured with "
2003 "B<CONFIG_SECCOMP_FILTER> enabled."
2007 #: build/C/man2/prctl.2:407
2009 "If B<SECCOMP_MODE_FILTER> filters permit B<fork>(2), then the seccomp mode "
2010 "is inherited by children created by B<fork>(2); if B<execve>(2) is "
2011 "permitted, then the seccomp mode is preserved across B<execve>(2). If the "
2012 "filters permit B<prctl>() calls, then additional filters can be added; they "
2013 "are run in order until the first non-allow result is seen."
2017 #: build/C/man2/prctl.2:410
2019 "For further information, see the kernel source file "
2020 "I<Documentation/prctl/seccomp_filter.txt>."
2024 #: build/C/man2/prctl.2:410
2026 msgid "B<PR_GET_SECCOMP> (since Linux 2.6.23)"
2030 #: build/C/man2/prctl.2:426
2032 "Return (as the function result) the secure computing mode of the calling "
2033 "thread. If the caller is not in secure computing mode, this operation "
2034 "returns 0; if the caller is in strict secure computing mode, then the "
2035 "B<prctl>() call will cause a B<SIGKILL> signal to be sent to the process. "
2036 "If the caller is in filter mode, and this system call is allowed by the "
2037 "seccomp filters, it returns 2. This operation is available only if the "
2038 "kernel is configured with B<CONFIG_SECCOMP> enabled."
2042 #: build/C/man2/prctl.2:426
2044 msgid "B<PR_SET_SECUREBITS> (since Linux 2.6.26)"
2048 #: build/C/man2/prctl.2:432
2050 "Set the \"securebits\" flags of the calling thread to the value supplied in "
2051 "I<arg2>. See B<capabilities>(7)."
2055 #: build/C/man2/prctl.2:432
2057 msgid "B<PR_GET_SECUREBITS> (since Linux 2.6.26)"
2061 #: build/C/man2/prctl.2:438
2063 "Return (as the function result) the \"securebits\" flags of the calling "
2064 "thread. See B<capabilities>(7)."
2068 #: build/C/man2/prctl.2:438
2070 msgid "B<PR_SET_THP_DISABLE> (since Linux 3.15)"
2073 #. commit a0715cc22601e8830ace98366c0c2bd8da52af52
2075 #: build/C/man2/prctl.2:454
2077 "Set the state of the \"THP disable\" flag for the calling thread. If "
2078 "I<arg2> has a nonzero value, the flag is set, otherwise it is cleared. "
2079 "Setting this flag provides a method for disabling transparent huge pages for "
2080 "jobs where the code cannot be modified, and using a malloc hook with "
2081 "B<madvise>(2) is not an option (i.e., statically allocated data). The "
2082 "setting of the \"THP disable\" flag is inherited by a child created via "
2083 "B<fork>(2) and is preserved across B<execve>(2)."
2087 #: build/C/man2/prctl.2:454
2089 msgid "B<PR_GET_THP_DISABLE> (since Linux 3.15)"
2093 #: build/C/man2/prctl.2:459
2095 "Return (via the function result) the current setting of the \"THP disable\" "
2096 "flag for the calling thread: either 1, if the flag is set, or 0, if it is "
2101 #: build/C/man2/prctl.2:459
2103 msgid "B<PR_GET_TID_ADDRESS> (since Linux 3.5)"
2106 #. commit 300f786b2683f8bb1ec0afb6e1851183a479c86d
2108 #: build/C/man2/prctl.2:474
2110 "Retrieve the I<clear_child_tid> address set by B<set_tid_address>(2) and "
2111 "the B<clone>(2) B<CLONE_CHILD_CLEARTID> flag, in the location pointed to by "
2112 "I<(int\\ **)\\ arg2>. This feature is available only if the kernel is built "
2113 "with the B<CONFIG_CHECKPOINT_RESTORE> option enabled."
2117 #: build/C/man2/prctl.2:474
2119 msgid "B<PR_SET_TIMERSLACK> (since Linux 2.6.28)"
2122 #. See https://lwn.net/Articles/369549/
2123 #. commit 6976675d94042fbd446231d1bd8b7de71a980ada
2124 #. It seems that it's not possible to set the timer slack to zero;
2125 #. The minimum value is 1? Seems a little strange.
2127 #: build/C/man2/prctl.2:493
2129 "Set the current timer slack for the calling thread to the nanosecond value "
2130 "supplied in I<arg2>. If I<arg2> is less than or equal to zero, reset the "
2131 "current timer slack to the thread's default timer slack value. The timer "
2132 "slack is used by the kernel to group timer expirations for the calling "
2133 "thread that are close to one another; as a consequence, timer expirations "
2134 "for the thread may be up to the specified number of nanoseconds late (but "
2135 "will never expire early). Grouping timer expirations can help reduce system "
2136 "power consumption by minimizing CPU wake-ups."
2139 #. List obtained by grepping for futex usage in glibc source
2141 #: build/C/man2/prctl.2:513
2143 "The timer expirations affected by timer slack are those set by B<select>(2), "
2144 "B<pselect>(2), B<poll>(2), B<ppoll>(2), B<epoll_wait>(2), B<epoll_pwait>(2), "
2145 "B<clock_nanosleep>(2), B<nanosleep>(2), and B<futex>(2) (and thus the "
2146 "library functions implemented via futexes, including "
2147 "B<pthread_cond_timedwait>(3), B<pthread_mutex_timedlock>(3), "
2148 "B<pthread_rwlock_timedrdlock>(3), B<pthread_rwlock_timedwrlock>(3), and "
2149 "B<sem_timedwait>(3))."
2153 #: build/C/man2/prctl.2:517
2155 "Timer slack is not applied to threads that are scheduled under a real-time "
2156 "scheduling policy (see B<sched_setscheduler>(2))."
2160 #: build/C/man2/prctl.2:534
2162 "Each thread has two associated timer slack values: a \"default\" value, and "
2163 "a \"current\" value. The current value is the one that governs grouping of "
2164 "timer expirations. When a new thread is created, the two timer slack values "
2165 "are made the same as the current value of the creating thread. Thereafter, "
2166 "a thread can adjust its current timer slack value via B<PR_SET_TIMERSLACK> "
2167 "(the default value can't be changed). The timer slack values of I<init> "
2168 "(PID 1), the ancestor of all processes, are 50,000 nanoseconds (50 "
2169 "microseconds). The timer slack values are preserved across B<execve>(2)."
2173 #: build/C/man2/prctl.2:534
2175 msgid "B<PR_GET_TIMERSLACK> (since Linux 2.6.28)"
2179 #: build/C/man2/prctl.2:538
2181 "Return (as the function result) the current timer slack value of the "
2186 #: build/C/man2/prctl.2:538
2188 msgid "B<PR_SET_TIMING> (since Linux 2.6.0-test4)"
2193 #. PR_TIMING_TIMESTAMP doesn't do anything in 2.6.26-rc8,
2194 #. and looking at the patch history, it appears
2195 #. that it never did anything.
2197 #: build/C/man2/prctl.2:555
2199 "Set whether to use (normal, traditional) statistical process timing or "
2200 "accurate timestamp-based process timing, by passing B<PR_TIMING_STATISTICAL> "
2201 "or B<PR_TIMING_TIMESTAMP> to I<arg2>. B<PR_TIMING_TIMESTAMP> is not "
2202 "currently implemented (attempting to set this mode will yield the error "
2207 #: build/C/man2/prctl.2:555
2209 msgid "B<PR_GET_TIMING> (since Linux 2.6.0-test4)"
2213 #: build/C/man2/prctl.2:559
2215 "Return (as the function result) which process timing method is currently in "
2220 #: build/C/man2/prctl.2:559
2222 msgid "B<PR_TASK_PERF_EVENTS_DISABLE> (since Linux 2.6.31)"
2226 #: build/C/man2/prctl.2:568
2228 "Disable all performance counters attached to the calling process, regardless "
2229 "of whether the counters were created by this process or another process. "
2230 "Performance counters created by the calling process for other processes are "
2231 "unaffected. For more information on performance counters, see the Linux "
2232 "kernel source file I<tools/perf/design.txt>."
2235 #. commit 1d1c7ddbfab358445a542715551301b7fc363e28
2237 #: build/C/man2/prctl.2:574
2239 "Originally called B<PR_TASK_PERF_COUNTERS_DISABLE>; renamed (with same "
2240 "numerical value) in Linux 2.6.32."
2244 #: build/C/man2/prctl.2:574
2246 msgid "B<PR_TASK_PERF_EVENTS_ENABLE> (since Linux 2.6.31)"
2250 #: build/C/man2/prctl.2:579
2252 "The converse of B<PR_TASK_PERF_EVENTS_DISABLE>; enable performance counters "
2253 "attached to the calling process."
2256 #. commit 1d1c7ddbfab358445a542715551301b7fc363e28
2257 #. commit cdd6c482c9ff9c55475ee7392ec8f672eddb7be6
2259 #: build/C/man2/prctl.2:586
2260 msgid "Originally called B<PR_TASK_PERF_COUNTERS_ENABLE>; renamed in Linux 2.6.32."
2264 #: build/C/man2/prctl.2:586
2266 msgid "B<PR_SET_TSC> (since Linux 2.6.26, x86 only)"
2270 #: build/C/man2/prctl.2:599
2272 "Set the state of the flag determining whether the timestamp counter can be "
2273 "read by the process. Pass B<PR_TSC_ENABLE> to I<arg2> to allow it to be "
2274 "read, or B<PR_TSC_SIGSEGV> to generate a B<SIGSEGV> when the process tries "
2275 "to read the timestamp counter."
2279 #: build/C/man2/prctl.2:599
2281 msgid "B<PR_GET_TSC> (since Linux 2.6.26, x86 only)"
2285 #: build/C/man2/prctl.2:605
2287 "Return the state of the flag determining whether the timestamp counter can "
2288 "be read, in the location pointed to by I<(int\\ *) arg2>."
2292 #: build/C/man2/prctl.2:605
2294 msgid "B<PR_SET_UNALIGN>"
2298 #: build/C/man2/prctl.2:615
2300 "(Only on: ia64, since Linux 2.3.48; parisc, since Linux 2.6.15; PowerPC, "
2301 "since Linux 2.6.18; Alpha, since Linux 2.6.22) Set unaligned access control "
2302 "bits to I<arg2>. Pass B<PR_UNALIGN_NOPRINT> to silently fix up unaligned "
2303 "user accesses, or B<PR_UNALIGN_SIGBUS> to generate B<SIGBUS> on unaligned "
2308 #: build/C/man2/prctl.2:615
2310 msgid "B<PR_GET_UNALIGN>"
2314 #: build/C/man2/prctl.2:622
2316 "(see B<PR_SET_UNALIGN> for information on versions and architectures) "
2317 "Return unaligned access control bits, in the location pointed to by I<(int\\ "
2322 #: build/C/man2/prctl.2:622
2324 msgid "B<PR_MCE_KILL> (since Linux 2.6.32)"
2328 #: build/C/man2/prctl.2:662
2330 "Set the machine check memory corruption kill policy for the current thread. "
2331 "If I<arg2> is B<PR_MCE_KILL_CLEAR>, clear the thread memory corruption kill "
2332 "policy and use the system-wide default. (The system-wide default is defined "
2333 "by I</proc/sys/vm/memory_failure_early_kill>; see B<proc>(5).) If I<arg2> "
2334 "is B<PR_MCE_KILL_SET>, use a thread-specific memory corruption kill policy. "
2335 "In this case, I<arg3> defines whether the policy is I<early kill> "
2336 "(B<PR_MCE_KILL_EARLY>), I<late kill> (B<PR_MCE_KILL_LATE>), or the "
2337 "system-wide default (B<PR_MCE_KILL_DEFAULT>). Early kill means that the "
2338 "thread receives a B<SIGBUS> signal as soon as hardware memory corruption is "
2339 "detected inside its address space. In late kill mode, the process is killed "
2340 "only when it accesses a corrupted page. See B<sigaction>(2) for more "
2341 "information on the B<SIGBUS> signal. The policy is inherited by children. "
2342 "The remaining unused B<prctl>() arguments must be zero for future "
2347 #: build/C/man2/prctl.2:662
2349 msgid "B<PR_MCE_KILL_GET> (since Linux 2.6.32)"
2353 #: build/C/man2/prctl.2:668
2355 "Return the current per-process machine check kill policy. All unused "
2356 "B<prctl>() arguments must be zero."
2360 #: build/C/man2/prctl.2:668
2362 msgid "B<PR_SET_MM> (since Linux 3.3)"
2365 #. commit 028ee4be34a09a6d48bdf30ab991ae933a7bc036
2367 #: build/C/man2/prctl.2:689
2369 "Modify certain kernel memory map descriptor fields of the calling process. "
2370 "Usually these fields are set by the kernel and dynamic loader (see "
2371 "B<ld.so>(8) for more information) and a regular application should not use "
2372 "this feature. However, there are cases, such as self-modifying programs, "
2373 "where a program might find it useful to change its own memory map. This "
2374 "feature is available only if the kernel is built with the "
2375 "B<CONFIG_CHECKPOINT_RESTORE> option enabled. The calling process must have "
2376 "the B<CAP_SYS_RESOURCE> capability. The value in I<arg2> is one of the "
2377 "options below, while I<arg3> provides a new value for the option."
2381 #: build/C/man2/prctl.2:690
2383 msgid "B<PR_SET_MM_START_CODE>"
2387 #: build/C/man2/prctl.2:699
2389 "Set the address above which the program text can run. The corresponding "
2390 "memory area must be readable and executable, but not writable or sharable "
2391 "(see B<mprotect>(2) and B<mmap>(2) for more information)."
2395 #: build/C/man2/prctl.2:699
2397 msgid "B<PR_SET_MM_END_CODE>"
2401 #: build/C/man2/prctl.2:704
2403 "Set the address below which the program text can run. The corresponding "
2404 "memory area must be readable and executable, but not writable or sharable."
2408 #: build/C/man2/prctl.2:704
2410 msgid "B<PR_SET_MM_START_DATA>"
2414 #: build/C/man2/prctl.2:710
2416 "Set the address above which initialized and uninitialized (bss) data are "
2417 "placed. The corresponding memory area must be readable and writable, but "
2418 "not executable or sharable."
2422 #: build/C/man2/prctl.2:710
2424 msgid "B<PR_SET_MM_END_DATA>"
2428 #: build/C/man2/prctl.2:716
2430 "Set the address below which initialized and uninitialized (bss) data are "
2431 "placed. The corresponding memory area must be readable and writable, but "
2432 "not executable or sharable."
2436 #: build/C/man2/prctl.2:716
2438 msgid "B<PR_SET_MM_START_STACK>"
2442 #: build/C/man2/prctl.2:720
2444 "Set the start address of the stack. The corresponding memory area must be "
2445 "readable and writable."
2449 #: build/C/man2/prctl.2:720
2451 msgid "B<PR_SET_MM_START_BRK>"
2455 #: build/C/man2/prctl.2:732
2457 "Set the address above which the program heap can be expanded with B<brk>(2) "
2458 "call. The address must be greater than the ending address of the current "
2459 "program data segment. In addition, the combined size of the resulting heap "
2460 "and the size of the data segment can't exceed the B<RLIMIT_DATA> resource "
2461 "limit (see B<setrlimit>(2))."
2465 #: build/C/man2/prctl.2:732
2467 msgid "B<PR_SET_MM_BRK>"
2471 #: build/C/man2/prctl.2:740
2473 "Set the current B<brk>(2) value. The requirements for the address are the "
2474 "same as for the B<PR_SET_MM_START_BRK> option."
2477 #. commit fe8c7f5cbf91124987106faa3bdf0c8b955c4cf7
2479 #: build/C/man2/prctl.2:743
2480 msgid "The following options are available since Linux 3.5."
2484 #: build/C/man2/prctl.2:743
2486 msgid "B<PR_SET_MM_ARG_START>"
2490 #: build/C/man2/prctl.2:746
2491 msgid "Set the address above which the program command line is placed."
2495 #: build/C/man2/prctl.2:746
2497 msgid "B<PR_SET_MM_ARG_END>"
2501 #: build/C/man2/prctl.2:749
2502 msgid "Set the address below which the program command line is placed."
2506 #: build/C/man2/prctl.2:749
2508 msgid "B<PR_SET_MM_ENV_START>"
2512 #: build/C/man2/prctl.2:752
2513 msgid "Set the address above which the program environment is placed."
2517 #: build/C/man2/prctl.2:752
2519 msgid "B<PR_SET_MM_ENV_END>"
2523 #: build/C/man2/prctl.2:755
2524 msgid "Set the address below which the program environment is placed."
2528 #: build/C/man2/prctl.2:768
2530 "The address passed with B<PR_SET_MM_ARG_START>, B<PR_SET_MM_ARG_END>, "
2531 "B<PR_SET_MM_ENV_START>, and B<PR_SET_MM_ENV_END> should belong to a process "
2532 "stack area. Thus, the corresponding memory area must be readable, writable, "
2533 "and (depending on the kernel configuration) have the B<MAP_GROWSDOWN> "
2534 "attribute set (see B<mmap>(2))."
2538 #: build/C/man2/prctl.2:768
2540 msgid "B<PR_SET_MM_AUXV>"
2544 #: build/C/man2/prctl.2:777
2546 "Set a new auxiliary vector. The I<arg3> argument should provide the address "
2547 "of the vector. The I<arg4> is the size of the vector."
2551 #: build/C/man2/prctl.2:777
2553 msgid "B<PR_SET_MM_EXE_FILE>"
2556 #. commit b32dfe377102ce668775f8b6b1461f7ad428f8b6
2558 #: build/C/man2/prctl.2:789
2560 "Supersede the I</proc/pid/exe> symbolic link with a new one pointing to a "
2561 "new executable file identified by the file descriptor provided in I<arg3> "
2562 "argument. The file descriptor should be obtained with a regular B<open>(2) "
2567 #: build/C/man2/prctl.2:796
2569 "To change the symbolic link, one needs to unmap all existing executable "
2570 "memory areas, including those created by the kernel itself (for example the "
2571 "kernel usually creates at least one executable memory area for the ELF "
2572 "I<.text> section)."
2576 #: build/C/man2/prctl.2:802
2578 "The second limitation is that such transitions can be done only once in a "
2579 "process life time. Any further attempts will be rejected. This should help "
2580 "system administrators monitor unusual symbolic-link transitions over all "
2581 "processes running on a system."
2585 #: build/C/man2/prctl.2:824
2587 "On success, B<PR_GET_DUMPABLE>, B<PR_GET_KEEPCAPS>, B<PR_GET_NO_NEW_PRIVS>, "
2588 "B<PR_GET_THP_DISABLE>, B<PR_CAPBSET_READ>, B<PR_GET_TIMING>, "
2589 "B<PR_GET_TIMERSLACK>, B<PR_GET_SECUREBITS>, B<PR_MCE_KILL_GET>, and (if it "
2590 "returns) B<PR_GET_SECCOMP> return the nonnegative values described above. "
2591 "All other I<option> values return 0 on success. On error, -1 is returned, "
2592 "and I<errno> is set appropriately."
2596 #: build/C/man2/prctl.2:829
2597 msgid "I<arg2> is an invalid address."
2601 #: build/C/man2/prctl.2:834
2602 msgid "The value of I<option> is not recognized."
2606 #: build/C/man2/prctl.2:846
2608 "I<option> is B<PR_MCE_KILL> or B<PR_MCE_KILL_GET> or B<PR_SET_MM>, and "
2609 "unused B<prctl>() arguments were not specified as zero."
2613 #: build/C/man2/prctl.2:851
2614 msgid "I<arg2> is not valid value for this I<option>."
2618 #: build/C/man2/prctl.2:860
2620 "I<option> is B<PR_SET_SECCOMP> or B<PR_GET_SECCOMP>, and the kernel was not "
2621 "configured with B<CONFIG_SECCOMP>."
2625 #: build/C/man2/prctl.2:866
2626 msgid "I<option> is B<PR_SET_MM>, and one of the following is true"
2630 #: build/C/man2/prctl.2:872
2631 msgid "I<arg4> or I<arg5> is nonzero;"
2635 #: build/C/man2/prctl.2:877
2637 "I<arg3> is greater than B<TASK_SIZE> (the limit on the size of the user "
2638 "address space for this architecture);"
2642 #: build/C/man2/prctl.2:887
2644 "I<arg2> is B<PR_SET_MM_START_CODE>, B<PR_SET_MM_END_CODE>, "
2645 "B<PR_SET_MM_START_DATA>, B<PR_SET_MM_END_DATA>, or B<PR_SET_MM_START_STACK>, "
2646 "and the permissions of the corresponding memory area are not as required;"
2650 #: build/C/man2/prctl.2:899
2652 "I<arg2> is B<PR_SET_MM_START_BRK> or B<PR_SET_MM_BRK>, and I<arg3> is less "
2653 "than or equal to the end of the data segment or specifies a value that would "
2654 "cause the B<RLIMIT_DATA> resource limit to be exceeded."
2658 #: build/C/man2/prctl.2:910
2660 "I<option> is B<PR_SET_PTRACER> and I<arg2> is not 0, B<PR_SET_PTRACER_ANY>, "
2661 "or the PID of an existing process."
2665 #: build/C/man2/prctl.2:918
2666 msgid "I<option> is B<PR_SET_PDEATHSIG> and I<arg2> is not a valid signal number."
2670 #: build/C/man2/prctl.2:929
2672 "I<option> is B<PR_SET_DUMPABLE> and I<arg2> is neither B<SUID_DUMP_DISABLE> "
2673 "nor B<SUID_DUMP_USER>."
2677 #: build/C/man2/prctl.2:938
2678 msgid "I<option> is B<PR_SET_TIMING> and I<arg2> is not B<PR_TIMING_STATISTICAL>."
2682 #: build/C/man2/prctl.2:952
2684 "I<option> is B<PR_SET_NO_NEW_PRIVS> and I<arg2> is not equal to 1 or "
2685 "I<arg3>, I<arg4>, or I<arg5> is nonzero."
2689 #: build/C/man2/prctl.2:964
2691 "I<option> is B<PR_GET_NO_NEW_PRIVS> and I<arg2>, I<arg3>, I<arg4>, or "
2692 "I<arg5> is nonzero."
2696 #: build/C/man2/prctl.2:975
2698 "I<option> is B<PR_SET_THP_DISABLE> and I<arg3>, I<arg4>, or I<arg5> is "
2703 #: build/C/man2/prctl.2:987
2705 "I<option> is B<PR_GET_THP_DISABLE> and I<arg2>, I<arg3>, I<arg4>, or I<arg5> "
2710 #: build/C/man2/prctl.2:999
2712 "I<option> is B<PR_SET_SECUREBITS>, and the caller does not have the "
2713 "B<CAP_SETPCAP> capability, or tried to unset a \"locked\" flag, or tried to "
2714 "set a flag whose corresponding locked flag was set (see B<capabilities>(7))."
2718 #: build/C/man2/prctl.2:1009
2720 "I<option> is B<PR_SET_KEEPCAPS>, and the callers's "
2721 "B<SECURE_KEEP_CAPS_LOCKED> flag is set (see B<capabilities>(7))."
2725 #: build/C/man2/prctl.2:1017
2727 "I<option> is B<PR_CAPBSET_DROP>, and the caller does not have the "
2728 "B<CAP_SETPCAP> capability."
2732 #: build/C/man2/prctl.2:1025
2734 "I<option> is B<PR_SET_MM>, and the caller does not have the "
2735 "B<CAP_SYS_RESOURCE> capability."
2739 #: build/C/man2/prctl.2:1025
2745 #: build/C/man2/prctl.2:1035
2747 "I<option> is B<PR_SET_MM>, and I<arg3> is B<PR_SET_MM_EXE_FILE>, the file is "
2752 #: build/C/man2/prctl.2:1035
2758 #: build/C/man2/prctl.2:1046
2760 "I<option> is B<PR_SET_MM>, I<arg3> is B<PR_SET_MM_EXE_FILE>, and this the "
2761 "second attempt to change the I</proc/pid/exe> symbolic link, which is "
2766 #: build/C/man2/prctl.2:1046 build/C/man2/signalfd.2:266 build/C/man2/timerfd_create.2:345
2771 #. The following can't actually happen, because prctl() in
2772 #. seccomp mode will cause SIGKILL.
2777 #. .BR PR_SET_SECCOMP ,
2778 #. and secure computing mode is already 1.
2780 #: build/C/man2/prctl.2:1065
2782 "I<option> is B<PR_SET_MM>, I<arg3> is B<PR_SET_MM_EXE_FILE>, and the file "
2783 "descriptor passed in I<arg4> is not valid."
2786 #. The library interface was added in glibc 2.0.6
2788 #: build/C/man2/prctl.2:1070
2789 msgid "The B<prctl>() system call was introduced in Linux 2.1.57."
2793 #: build/C/man2/prctl.2:1077
2795 "This call is Linux-specific. IRIX has a B<prctl>() system call (also "
2796 "introduced in Linux 2.1.44 as irix_prctl on the MIPS architecture), with "
2801 #: build/C/man2/prctl.2:1079
2802 msgid "B<ptrdiff_t prctl(int >I<option>B<, int >I<arg2>B<, int >I<arg3>B<);>"
2806 #: build/C/man2/prctl.2:1084
2808 "and options to get the maximum number of processes per user, get the maximum "
2809 "number of processors the calling process can use, find out whether a "
2810 "specified process is currently blocked, get or set the maximum stack size, "
2815 #: build/C/man2/prctl.2:1087
2816 msgid "B<signal>(2), B<core>(5)"
2820 #: build/C/man3/profil.3:28
2826 #: build/C/man3/profil.3:31
2827 msgid "profil - execution time profile"
2831 #: build/C/man3/profil.3:34
2833 msgid "B<#include E<lt>unistd.hE<gt>>\n"
2837 #: build/C/man3/profil.3:37
2840 "B<int profil(unsigned short *>I<buf>B<, size_t >I<bufsiz>B<,>\n"
2841 "B< size_t >I<offset>B<, unsigned int >I<scale>B<);>\n"
2845 #: build/C/man3/profil.3:46
2846 msgid "B<profil>(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE\\ E<lt>\\ 500)"
2850 #: build/C/man3/profil.3:68
2852 "This routine provides a means to find out in what areas your program spends "
2853 "most of its time. The argument I<buf> points to I<bufsiz> bytes of core. "
2854 "Every virtual 10 milliseconds, the user's program counter (PC) is examined: "
2855 "I<offset> is subtracted and the result is multiplied by I<scale> and divided "
2856 "by 65536. If the resulting value is less than I<bufsiz>, then the "
2857 "corresponding entry in I<buf> is incremented. If I<buf> is NULL, profiling "
2862 #: build/C/man3/profil.3:70
2863 msgid "Zero is always returned."
2867 #: build/C/man3/profil.3:72
2868 msgid "Similar to a call in SVr4 (but not POSIX.1-2001)."
2872 #: build/C/man3/profil.3:78
2874 "B<profil>() cannot be used on a program that also uses B<ITIMER_PROF> "
2875 "interval timers (see B<setitimer>(2))."
2879 #: build/C/man3/profil.3:81
2881 "True kernel profiling provides more accurate results. Libc 4.4 contained a "
2882 "kernel patch providing a system call profil."
2886 #: build/C/man3/profil.3:87
2887 msgid "B<gprof>(1), B<sprof>(1), B<setitimer>(2), B<sigaction>(2), B<signal>(2)"
2891 #: build/C/man3/psignal.3:30
2897 #: build/C/man3/psignal.3:30
2903 #: build/C/man3/psignal.3:30 build/C/man3/raise.3:29 build/C/man7/sigevent.7:26
2909 #: build/C/man3/psignal.3:33
2910 msgid "psignal, psiginfo - print signal message"
2914 #: build/C/man3/psignal.3:39
2917 "B<void psignal(int >I<sig>B<, const char *>I<s>B<);>\n"
2918 "B<void psiginfo(const siginfo_t *>I<pinfo>B<, const char *>I<s>B<);>\n"
2922 #: build/C/man3/psignal.3:41
2924 msgid "B<extern const char *const >I<sys_siglist>B<[];>\n"
2928 #: build/C/man3/psignal.3:50
2929 msgid "B<psignal>(): _SVID_SOURCE || _BSD_SOURCE"
2933 #: build/C/man3/psignal.3:53
2935 "B<psiginfo>(): _XOPEN_SOURCE\\ E<gt>=\\ 700 || _POSIX_C_SOURCE\\ E<gt>=\\ "
2940 #: build/C/man3/psignal.3:56
2941 msgid "I<sys_siglist>: _BSD_SOURCE"
2945 #: build/C/man3/psignal.3:65
2947 "The B<psignal>() function displays a message on I<stderr> consisting of the "
2948 "string I<s>, a colon, a space, a string describing the signal number I<sig>, "
2949 "and a trailing newline. If the string I<s> is NULL or empty, the colon and "
2950 "space are omitted. If I<sig> is invalid, the message displayed will "
2951 "indicate an unknown signal."
2955 #: build/C/man3/psignal.3:86
2957 "The B<psiginfo>() function is like B<psignal>(), except that it displays "
2958 "information about the signal described by I<pinfo>, which should point to a "
2959 "valid I<siginfo_t> structure. As well as the signal description, "
2960 "B<psiginfo>() displays information about the origin of the signal, and "
2961 "other information relevant to the signal (e.g., the relevant memory address "
2962 "for hardware-generated signals, the child process ID for B<SIGCHLD>, and the "
2963 "user ID and process ID of the sender, for signals set using B<kill>(2) or "
2968 #: build/C/man3/psignal.3:89
2970 "The array I<sys_siglist> holds the signal description strings indexed by "
2975 #: build/C/man3/psignal.3:95
2976 msgid "The B<psignal>() and B<psiginfo>() functions return no value."
2980 #: build/C/man3/psignal.3:99
2981 msgid "The B<psiginfo>() function was added to glibc in version 2.10."
2985 #: build/C/man3/psignal.3:101
2986 msgid "POSIX.1-2008, 4.3BSD."
2990 #: build/C/man3/psignal.3:105
2991 msgid "In glibc versions up to 2.12, B<psiginfo>() had the following bugs:"
2994 #. FIXME . http://sourceware.org/bugzilla/show_bug.cgi?id=12107
2995 #. Reportedly now fixed; check glibc 2.13
2997 #: build/C/man3/psignal.3:109
2998 msgid "In some circumstances, a trailing newline is not printed."
3001 #. FIXME . http://sourceware.org/bugzilla/show_bug.cgi?id=12108
3002 #. Reportedly now fixed; check glibc 2.13
3004 #: build/C/man3/psignal.3:113
3005 msgid "Additional details are not displayed for real-time signals."
3009 #: build/C/man3/psignal.3:118
3010 msgid "B<sigaction>(2), B<perror>(3), B<strsignal>(3), B<signal>(7)"
3014 #: build/C/man3/raise.3:29
3020 #: build/C/man3/raise.3:29
3026 #: build/C/man3/raise.3:32
3027 msgid "raise - send a signal to the caller"
3031 #: build/C/man3/raise.3:37
3033 msgid "B<int raise(int >I<sig>B<);>\n"
3037 #: build/C/man3/raise.3:43
3039 "The B<raise>() function sends a signal to the calling process or thread. "
3040 "In a single-threaded program it is equivalent to"
3044 #: build/C/man3/raise.3:47
3046 msgid "kill(getpid(), sig);\n"
3050 #: build/C/man3/raise.3:51
3051 msgid "In a multithreaded program it is equivalent to"
3055 #: build/C/man3/raise.3:55
3057 msgid "pthread_kill(pthread_self(), sig);\n"
3061 #: build/C/man3/raise.3:61
3063 "If the signal causes a handler to be called, B<raise>() will return only "
3064 "after the signal handler has returned."
3068 #: build/C/man3/raise.3:64
3069 msgid "B<raise>() returns 0 on success, and nonzero for failure."
3073 #: build/C/man3/raise.3:69
3074 msgid "The B<raise>() function is thread-safe."
3078 #: build/C/man3/raise.3:71 build/C/man2/signal.2:112
3079 msgid "C89, C99, POSIX.1-2001."
3082 #. 2.3.2 used the obsolete tkill(), if available.
3084 #: build/C/man3/raise.3:82
3086 "Since version 2.3.3, glibc implements B<raise>() by calling B<tgkill>(2), "
3087 "if the kernel supports that system call. Older glibc versions implemented "
3088 "B<raise>() using B<kill>(2)."
3092 #: build/C/man3/raise.3:89
3094 "B<getpid>(2), B<kill>(2), B<sigaction>(2), B<signal>(2), B<pthread_kill>(3), "
3099 #: build/C/man2/restart_syscall.2:33
3101 msgid "RESTART_SYSCALL"
3105 #: build/C/man2/restart_syscall.2:36
3106 msgid "restart_syscall - restart a system call after interruption by a stop signal"
3110 #: build/C/man2/restart_syscall.2:38
3111 msgid "B<int restart_syscall(void);>"
3115 #: build/C/man2/restart_syscall.2:41
3116 msgid "I<Note>: There is no glibc wrapper for this system call; see NOTES."
3120 #: build/C/man2/restart_syscall.2:53
3122 "The B<restart_syscall>() system call is used to restart certain system "
3123 "calls after a process that was stopped by a signal (e.g., B<SIGSTOP> or "
3124 "B<SIGTSTP>) is later resumed after receiving a B<SIGCONT> signal. This "
3125 "system call is designed only for internal use by the kernel."
3128 #. These system calls correspond to the special internal errno value
3129 #. ERESTART_RESTARTBLOCK. Each of the system calls has a "restart"
3130 #. helper function that is invoked by restart_syscall().
3131 #. Notable (as at Linux 3.17) is that poll() has such a "restart"
3132 #. function, but ppoll(), select(), and pselect() do not.
3133 #. This means that the latter system calls do not take account of the
3134 #. time spent in the stopped state when restarting.
3136 #: build/C/man2/restart_syscall.2:88
3138 "B<restart_syscall>() is used for restarting only those system calls that, "
3139 "when restarted, should adjust their time-related parameters\\(emnamely "
3140 "B<poll>(2) (since Linux 2.6.24), B<nanosleep>(2) (since Linux 2.6), "
3141 "B<clock_nanosleep>(2) (since Linux 2.6), and B<futex>(2), when employed "
3142 "with the B<FUTEX_WAIT> (since Linux 2.6.22) and B<FUTEX_WAIT_BITSET> (since "
3143 "Linux 2.6.31) operations. B<restart_syscall>() restarts the interrupted "
3144 "system call with a time argument that is suitably adjusted to account for "
3145 "the time that has already elapsed (including the time where the process was "
3146 "stopped by a signal). Without the B<restart_syscall>() mechanism, "
3147 "restarting these system calls would not correctly deduct the already elapsed "
3148 "time when the process continued execution."
3152 #: build/C/man2/restart_syscall.2:92
3154 "The return value of B<restart_syscall>() is the return value of whatever "
3155 "system call is being restarted."
3159 #: build/C/man2/restart_syscall.2:96
3161 "I<errno> is set as per the errors for whatever system call is being "
3162 "restarted by B<restart_syscall>()."
3166 #: build/C/man2/restart_syscall.2:100
3167 msgid "The B<restart_syscall>() system call is present since Linux 2.6."
3171 #: build/C/man2/restart_syscall.2:102
3172 msgid "This system call is Linux-specific."
3176 #: build/C/man2/restart_syscall.2:106
3178 "There is no glibc wrapper for this system call, because it is intended for "
3179 "use only by the kernel and should never be called by applications."
3183 #: build/C/man2/restart_syscall.2:128
3185 "The kernel uses B<restart_syscall>() to ensure that when a system call is "
3186 "restarted after a process has been stopped by a signal and then resumed by "
3187 "B<SIGCONT>, then the time that the process spent in the stopped state is "
3188 "counted against the timeout interval specified in the original system call. "
3189 "In the case of system calls that take a timeout argument and automatically "
3190 "restart after a stop signal plus B<SIGCONT>, but which do not have the "
3191 "B<restart_syscall>(2) mechanism built in, then, after the process resumes "
3192 "execution, the time that the process spent in the stop state is I<not> "
3193 "counted against the timeout value. Notable examples of system calls that "
3194 "suffer this problem are B<ppoll>(2), B<select>(2), and B<pselect>(2)."
3198 #: build/C/man2/restart_syscall.2:135
3200 "From user space, the operation of B<restart_syscall>(2) is largely "
3201 "invisible: to the process that made the system call that is restarted, it "
3202 "appears as though that system call executed and returned in the usual "
3206 #. FIXME . ppoll(2), select(2), and pselect(2)
3207 #. should probably get the restart_syscall() treatment:
3208 #. If a select() call is suspended by stop-sig+SIGCONT, the time
3209 #. spent suspended is *not* deducted when the select() is restarted.
3210 #. FIXME . check whether recvmmsg() handles stop-sig+SIGCONT properly.
3212 #: build/C/man2/restart_syscall.2:144
3213 msgid "B<sigaction>(2), B<sigreturn>(2), B<signal>(7)"
3217 #: build/C/man2/rt_sigqueueinfo.2:25
3219 msgid "RT_SIGQUEUEINFO"
3223 #: build/C/man2/rt_sigqueueinfo.2:25
3229 #: build/C/man2/rt_sigqueueinfo.2:28
3230 msgid "rt_sigqueueinfo, rt_tgsigqueueinfo - queue a signal and data"
3234 #: build/C/man2/rt_sigqueueinfo.2:31
3237 "B<int rt_sigqueueinfo(pid_t >I<tgid>B<, int >I<sig>B<, siginfo_t "
3242 #: build/C/man2/rt_sigqueueinfo.2:34
3245 "B<int rt_tgsigqueueinfo(pid_t >I<tgid>B<, pid_t >I<tid>B<, int >I<sig>B<,>\n"
3246 "B< siginfo_t *>I<uinfo>B<);>\n"
3250 #: build/C/man2/rt_sigqueueinfo.2:38 build/C/man2/sgetmask.2:36 build/C/man2/tkill.2:41
3251 msgid "I<Note>: There are no glibc wrappers for these system calls; see NOTES."
3255 #: build/C/man2/rt_sigqueueinfo.2:50
3257 "The B<rt_sigqueueinfo>() and B<rt_tgsigqueueinfo>() system calls are the "
3258 "low-level interfaces used to send a signal plus data to a process or "
3259 "thread. The receiver of the signal can obtain the accompanying data by "
3260 "establishing a signal handler with the B<sigaction>(2) B<SA_SIGINFO> flag."
3264 #: build/C/man2/rt_sigqueueinfo.2:56
3266 "These system calls are not intended for direct application use; they are "
3267 "provided to allow the implementation of B<sigqueue>(3) and "
3268 "B<pthread_sigqueue>(3)."
3272 #: build/C/man2/rt_sigqueueinfo.2:68
3274 "The B<rt_sigqueueinfo>() system call sends the signal I<sig> to the thread "
3275 "group with the ID I<tgid>. (The term \"thread group\" is synonymous with "
3276 "\"process\", and I<tid> corresponds to the traditional UNIX process ID.) "
3277 "The signal will be delivered to an arbitrary member of the thread group "
3278 "(i.e., one of the threads that is not currently blocking the signal)."
3282 #: build/C/man2/rt_sigqueueinfo.2:79
3284 "The I<uinfo> argument specifies the data to accompany the signal. This "
3285 "argument is a pointer to a structure of type I<siginfo_t>, described in "
3286 "B<sigaction>(2) (and defined by including I<E<lt>sigaction.hE<gt>>). The "
3287 "caller should set the following fields in this structure:"
3291 #: build/C/man2/rt_sigqueueinfo.2:79 build/C/man7/sigevent.7:88 build/C/man2/wait.2:316
3298 #: build/C/man2/rt_sigqueueinfo.2:95
3300 "This must be one of the B<SI_*> codes in the Linux kernel source file "
3301 "I<include/asm-generic/siginfo.h>, with the restriction that the code must be "
3302 "negative (i.e., cannot be B<SI_USER>, which is used by the kernel to "
3303 "indicate a signal sent by B<kill>(2)) and cannot (since Linux 2.6.39) be "
3304 "B<SI_TKILL> (which is used by the kernel to indicate a signal sent using "
3309 #: build/C/man2/rt_sigqueueinfo.2:95 build/C/man2/wait.2:295
3315 #: build/C/man2/rt_sigqueueinfo.2:99
3316 msgid "This should be set to a process ID, typically the process ID of the sender."
3320 #: build/C/man2/rt_sigqueueinfo.2:99 build/C/man2/wait.2:298
3326 #: build/C/man2/rt_sigqueueinfo.2:103
3327 msgid "This should be set to a user ID, typically the real user ID of the sender."
3331 #: build/C/man2/rt_sigqueueinfo.2:103 build/C/man7/sigevent.7:96
3337 #: build/C/man2/rt_sigqueueinfo.2:110
3339 "This field contains the user data to accompany the signal. For more "
3340 "information, see the description of the last (I<union sigval>) argument of "
3345 #: build/C/man2/rt_sigqueueinfo.2:117
3347 "Internally, the kernel sets the I<si_signo> field to the value specified in "
3348 "I<sig>, so that the receiver of the signal can also obtain the signal number "
3353 #: build/C/man2/rt_sigqueueinfo.2:129
3355 "The B<rt_tgsigqueueinfo>() system call is like B<rt_sigqueueinfo>(), but "
3356 "sends the signal and data to the single thread specified by the combination "
3357 "of I<tgid>, a thread group ID, and I<tid>, a thread in that thread group."
3361 #: build/C/man2/rt_sigqueueinfo.2:134
3363 "On success, these system calls return 0. On error, they return -1 and "
3364 "I<errno> is set to indicate the error."
3368 #: build/C/man2/rt_sigqueueinfo.2:135 build/C/man3/sigqueue.3:92 build/C/man2/sigwaitinfo.2:115 build/C/man2/timer_create.2:178
3374 #: build/C/man2/rt_sigqueueinfo.2:141 build/C/man3/sigqueue.3:98
3376 "The limit of signals which may be queued has been reached. (See "
3377 "B<signal>(7) for further information.)"
3381 #: build/C/man2/rt_sigqueueinfo.2:148
3382 msgid "I<sig>, I<tgid>, or I<tid> was invalid."
3386 #: build/C/man2/rt_sigqueueinfo.2:156
3388 "The caller does not have permission to send the signal to the target. For "
3389 "the required permissions, see B<kill>(2). Or: I<uinfo-E<gt>si_code> is "
3394 #: build/C/man2/rt_sigqueueinfo.2:162
3395 msgid "B<rt_sigqueueinfo>(): No thread group matching I<tgid> was found."
3399 #: build/C/man2/rt_sigqueueinfo.2:169
3400 msgid "B<rt_tgsigqueinfo>(): No thread matching I<tgid> and I<tid> was found."
3404 #: build/C/man2/rt_sigqueueinfo.2:176
3406 "The B<rt_sigqueueinfo>() system call was added to Linux in version 2.2. "
3407 "The B<rt_tgsigqueueinfo>() system call was added to Linux in version "
3412 #: build/C/man2/rt_sigqueueinfo.2:178 build/C/man2/sgetmask.2:75 build/C/man2/timerfd_create.2:380
3413 msgid "These system calls are Linux-specific."
3417 #: build/C/man2/rt_sigqueueinfo.2:183
3419 "Since these system calls are not intended for application use, there are no "
3420 "glibc wrapper functions; use B<syscall>(2) in the unlikely case that you "
3421 "want to call them directly."
3425 #: build/C/man2/rt_sigqueueinfo.2:188
3427 "As with B<kill>(2), the null signal (0) can be used to check if the "
3428 "specified process or thread exists."
3432 #: build/C/man2/rt_sigqueueinfo.2:196
3434 "B<kill>(2), B<sigaction>(2), B<sigprocmask>(2), B<tgkill>(2), "
3435 "B<pthread_sigqueue>(3), B<sigqueue>(3), B<signal>(7)"
3439 #: build/C/man2/s390_runtime_instr.2:25
3441 msgid "S390_RUNTIME_INSTR"
3445 #: build/C/man2/s390_runtime_instr.2:25
3451 #: build/C/man2/s390_runtime_instr.2:28
3452 msgid "s390_runtime_instr - enable/disable s390 CPU run-time instrumentation"
3456 #: build/C/man2/s390_runtime_instr.2:31
3458 msgid "B<#include E<lt>asm/runtime_instr.hE<gt>>\n"
3462 #: build/C/man2/s390_runtime_instr.2:33
3464 msgid "B<int s390_runtime_instr(int >I<command>B<, int >I<signum>B<);>\n"
3468 #: build/C/man2/s390_runtime_instr.2:39
3470 "The B<s390_runtime_instr>() system call starts or stops CPU run-time "
3471 "instrumentation for the calling thread."
3475 #: build/C/man2/s390_runtime_instr.2:47
3477 "The I<command> argument controls whether run-time instrumentation is started "
3478 "(B<S390_RUNTIME_INSTR_START>, 1) or stopped (B<S390_RUNTIME_INSTR_STOP>, 2) "
3479 "for the calling thread."
3483 #: build/C/man2/s390_runtime_instr.2:54
3485 "The I<signum> argument specifies the number of a real-time signal. The "
3486 "real-time signal is sent to the thread if the run-time instrumentation "
3487 "buffer is full or if the run-time-instrumentation-halted interrupt occurred."
3491 #: build/C/man2/s390_runtime_instr.2:65
3493 "On success, B<s390_runtime_instr>() returns 0 and enables the thread for "
3494 "run-time instrumentation by assigning the thread a default run-time "
3495 "instrumentation control block. The caller can then read and modify the "
3496 "control block and start the run-time instrumentation. On error, -1 is "
3497 "returned and I<errno> is set to one of the error codes listed below."
3501 #: build/C/man2/s390_runtime_instr.2:73
3503 "The value specified in I<command> is not a valid command or the value "
3504 "specified in I<signum> is not a real-time signal number."
3508 #: build/C/man2/s390_runtime_instr.2:76
3509 msgid "Allocating memory for the run-time instrumentation control block failed."
3513 #: build/C/man2/s390_runtime_instr.2:76
3515 msgid "B<EOPNOTSUPP>"
3519 #: build/C/man2/s390_runtime_instr.2:79
3520 msgid "The run-time instrumentation facility is not available."
3524 #: build/C/man2/s390_runtime_instr.2:81
3525 msgid "This system call is available since Linux 3.7."
3529 #: build/C/man2/s390_runtime_instr.2:84
3531 "This Linux-specific system call is available only on the s390 architecture. "
3532 "The run-time instrumentation facility is available beginning with System z "
3537 #: build/C/man2/s390_runtime_instr.2:88
3539 "Glibc does not provide a wrapper for this system call, use B<syscall>(2) to "
3544 #: build/C/man2/s390_runtime_instr.2:91
3545 msgid "B<syscall>(2), B<signal>(7)"
3549 #: build/C/man2/sgetmask.2:26
3555 #: build/C/man2/sgetmask.2:29
3556 msgid "sgetmask, ssetmask - manipulation of signal mask (obsolete)"
3560 #: build/C/man2/sgetmask.2:31
3561 msgid "B<long sgetmask(void);>"
3565 #: build/C/man2/sgetmask.2:33
3566 msgid "B<long ssetmask(long >I<newmask>B<);>"
3570 #: build/C/man2/sgetmask.2:42
3572 "These system calls are obsolete. I<Do not use them>; use B<sigprocmask>(2) "
3577 #: build/C/man2/sgetmask.2:45
3578 msgid "B<sgetmask>() returns the signal mask of the calling process."
3582 #: build/C/man2/sgetmask.2:50
3584 "B<ssetmask>() sets the signal mask of the calling process to the value "
3585 "given in I<newmask>. The previous signal mask is returned."
3589 #: build/C/man2/sgetmask.2:59
3591 "The signal masks dealt with by these two system calls are plain bit masks "
3592 "(unlike the I<sigset_t> used by B<sigprocmask>(2)); use B<sigmask>(3) to "
3593 "create and inspect these masks."
3597 #: build/C/man2/sgetmask.2:64
3599 "B<sgetmask>() always successfully returns the signal mask. B<ssetmask>() "
3600 "always succeeds, and returns the previous signal mask."
3604 #: build/C/man2/sgetmask.2:66
3605 msgid "These system calls always succeed."
3608 #. f6187769dae48234f3877df3c4d99294cc2254fa
3610 #: build/C/man2/sgetmask.2:73
3612 "Since Linux 3.16, support for these system calls is optional, depending on "
3613 "whether the kernel was built with the B<CONFIG_SGETMASK_SYSCALL> option."
3617 #: build/C/man2/sgetmask.2:79
3619 "Glibc does not provide wrappers for these obsolete system calls; in the "
3620 "unlikely event that you want to call them, use B<syscall>(2)."
3624 #: build/C/man2/sgetmask.2:82
3626 "These system calls are unaware of signal numbers greater than 31 (i.e., "
3627 "real-time signals)."
3631 #: build/C/man2/sgetmask.2:84
3632 msgid "These system calls do not exist on x86-64."
3636 #: build/C/man2/sgetmask.2:89
3637 msgid "It is not possible to block B<SIGSTOP> or B<SIGKILL>."
3641 #: build/C/man2/sgetmask.2:92
3642 msgid "B<sigprocmask>(2), B<signal>(7)"
3646 #: build/C/man2/sigaction.2:47
3652 #: build/C/man2/sigaction.2:50
3653 msgid "sigaction - examine and change a signal action"
3657 #: build/C/man2/sigaction.2:56
3660 "B<int sigaction(int >I<signum>B<, const struct sigaction *>I<act>B<,>\n"
3661 "B< struct sigaction *>I<oldact>B<);>\n"
3665 #: build/C/man2/sigaction.2:66
3667 "B<sigaction>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
3672 #: build/C/man2/sigaction.2:69
3673 msgid "I<siginfo_t>: _POSIX_C_SOURCE E<gt>= 199309L"
3677 #: build/C/man2/sigaction.2:78
3679 "The B<sigaction>() system call is used to change the action taken by a "
3680 "process on receipt of a specific signal. (See B<signal>(7) for an overview "
3685 #: build/C/man2/sigaction.2:84
3687 "I<signum> specifies the signal and can be any valid signal except B<SIGKILL> "
3692 #: build/C/man2/sigaction.2:95
3694 "If I<act> is non-NULL, the new action for signal I<signum> is installed from "
3695 "I<act>. If I<oldact> is non-NULL, the previous action is saved in "
3700 #: build/C/man2/sigaction.2:99
3701 msgid "The I<sigaction> structure is defined as something like:"
3705 #: build/C/man2/sigaction.2:109
3708 "struct sigaction {\n"
3709 " void (*sa_handler)(int);\n"
3710 " void (*sa_sigaction)(int, siginfo_t *, void *);\n"
3711 " sigset_t sa_mask;\n"
3713 " void (*sa_restorer)(void);\n"
3718 #: build/C/man2/sigaction.2:116
3720 "On some architectures a union is involved: do not assign to both "
3721 "I<sa_handler> and I<sa_sigaction>."
3725 #: build/C/man2/sigaction.2:125
3727 "The I<sa_restorer> field is not intended for application use. (POSIX does "
3728 "not specify a I<sa_restorer> field.) Some further details of purpose of "
3729 "this field can be found in B<sigreturn>(2)."
3733 #: build/C/man2/sigaction.2:135
3735 "I<sa_handler> specifies the action to be associated with I<signum> and may "
3736 "be B<SIG_DFL> for the default action, B<SIG_IGN> to ignore this signal, or a "
3737 "pointer to a signal handling function. This function receives the signal "
3738 "number as its only argument."
3742 #: build/C/man2/sigaction.2:157
3744 "If B<SA_SIGINFO> is specified in I<sa_flags>, then I<sa_sigaction> (instead "
3745 "of I<sa_handler>) specifies the signal-handling function for I<signum>. "
3746 "This function receives the signal number as its first argument, a pointer to "
3747 "a I<siginfo_t> as its second argument and a pointer to a I<ucontext_t> (cast "
3748 "to I<void\\ *>) as its third argument. (Commonly, the handler function "
3749 "doesn't make any use of the third argument. See B<getcontext>(3) for "
3750 "further information about I<ucontext_t>.)"
3754 #: build/C/man2/sigaction.2:167
3756 "I<sa_mask> specifies a mask of signals which should be blocked (i.e., added "
3757 "to the signal mask of the thread in which the signal handler is invoked) "
3758 "during execution of the signal handler. In addition, the signal which "
3759 "triggered the handler will be blocked, unless the B<SA_NODEFER> flag is "
3764 #: build/C/man2/sigaction.2:171
3766 "I<sa_flags> specifies a set of flags which modify the behavior of the "
3767 "signal. It is formed by the bitwise OR of zero or more of the following:"
3771 #: build/C/man2/sigaction.2:172
3773 msgid "B<SA_NOCLDSTOP>"
3777 #: build/C/man2/sigaction.2:189
3779 "If I<signum> is B<SIGCHLD>, do not receive notification when child processes "
3780 "stop (i.e., when they receive one of B<SIGSTOP>, B<SIGTSTP>, B<SIGTTIN>, or "
3781 "B<SIGTTOU>) or resume (i.e., they receive B<SIGCONT>) (see B<wait>(2)). "
3782 "This flag is meaningful only when establishing a handler for B<SIGCHLD>."
3786 #: build/C/man2/sigaction.2:189
3788 msgid "B<SA_NOCLDWAIT> (since Linux 2.6)"
3791 #. To be precise: Linux 2.5.60 -- MTK
3793 #: build/C/man2/sigaction.2:203
3795 "If I<signum> is B<SIGCHLD>, do not transform children into zombies when they "
3796 "terminate. See also B<waitpid>(2). This flag is meaningful only when "
3797 "establishing a handler for B<SIGCHLD>, or when setting that signal's "
3798 "disposition to B<SIG_DFL>."
3802 #: build/C/man2/sigaction.2:215
3804 "If the B<SA_NOCLDWAIT> flag is set when establishing a handler for "
3805 "B<SIGCHLD>, POSIX.1 leaves it unspecified whether a B<SIGCHLD> signal is "
3806 "generated when a child process terminates. On Linux, a B<SIGCHLD> signal is "
3807 "generated in this case; on some other implementations, it is not."
3811 #: build/C/man2/sigaction.2:215
3813 msgid "B<SA_NODEFER>"
3817 #: build/C/man2/sigaction.2:222
3819 "Do not prevent the signal from being received from within its own signal "
3820 "handler. This flag is meaningful only when establishing a signal handler. "
3821 "B<SA_NOMASK> is an obsolete, nonstandard synonym for this flag."
3825 #: build/C/man2/sigaction.2:222
3827 msgid "B<SA_ONSTACK>"
3831 #: build/C/man2/sigaction.2:228
3833 "Call the signal handler on an alternate signal stack provided by "
3834 "B<sigaltstack>(2). If an alternate stack is not available, the default "
3835 "stack will be used. This flag is meaningful only when establishing a signal "
3840 #: build/C/man2/sigaction.2:228
3842 msgid "B<SA_RESETHAND>"
3846 #: build/C/man2/sigaction.2:234
3848 "Restore the signal action to the default upon entry to the signal handler. "
3849 "This flag is meaningful only when establishing a signal handler. "
3850 "B<SA_ONESHOT> is an obsolete, nonstandard synonym for this flag."
3854 #: build/C/man2/sigaction.2:234
3856 msgid "B<SA_RESTART>"
3860 #: build/C/man2/sigaction.2:242
3862 "Provide behavior compatible with BSD signal semantics by making certain "
3863 "system calls restartable across signals. This flag is meaningful only when "
3864 "establishing a signal handler. See B<signal>(7) for a discussion of system "
3869 #: build/C/man2/sigaction.2:242
3871 msgid "B<SA_RESTORER>"
3875 #: build/C/man2/sigaction.2:251
3877 "I<Not intended for application use>. This flag is used by C libraries to "
3878 "indicate that the I<sa_restorer> field contains the address of a \"signal "
3879 "trampoline\". See B<sigreturn>(2) for more details."
3883 #: build/C/man2/sigaction.2:251
3885 msgid "B<SA_SIGINFO> (since Linux 2.2)"
3890 #. field was added in Linux 2.1.86.)
3892 #: build/C/man2/sigaction.2:262
3894 "The signal handler takes three arguments, not one. In this case, "
3895 "I<sa_sigaction> should be set instead of I<sa_handler>. This flag is "
3896 "meaningful only when establishing a signal handler."
3900 #: build/C/man2/sigaction.2:269
3902 "The I<siginfo_t> argument to I<sa_sigaction> is a struct with the following "
3907 #. The siginfo_t 'si_trapno' field seems to be used only on SPARC and Alpha;
3908 #. this page could use a little more detail on its purpose there.
3909 #. In the kernel: si_tid
3911 #: build/C/man2/sigaction.2:300
3915 " int si_signo; /* Signal number */\n"
3916 " int si_errno; /* An errno value */\n"
3917 " int si_code; /* Signal code */\n"
3918 " int si_trapno; /* Trap number that caused\n"
3919 " hardware-generated signal\n"
3920 " (unused on most architectures) */\n"
3921 " pid_t si_pid; /* Sending process ID */\n"
3922 " uid_t si_uid; /* Real user ID of sending process */\n"
3923 " int si_status; /* Exit value or signal */\n"
3924 " clock_t si_utime; /* User time consumed */\n"
3925 " clock_t si_stime; /* System time consumed */\n"
3926 " sigval_t si_value; /* Signal value */\n"
3927 " int si_int; /* POSIX.1b signal */\n"
3928 " void *si_ptr; /* POSIX.1b signal */\n"
3929 " int si_overrun; /* Timer overrun count; POSIX.1b timers */\n"
3930 " int si_timerid; /* Timer ID; POSIX.1b timers */\n"
3931 " void *si_addr; /* Memory location which caused fault */\n"
3932 " long si_band; /* Band event (was I<int> in\n"
3933 " glibc 2.3.2 and earlier) */\n"
3934 " int si_fd; /* File descriptor */\n"
3935 " short si_addr_lsb; /* Least significant bit of address\n"
3936 " (since Linux 2.6.32) */\n"
3941 #: build/C/man2/sigaction.2:309
3943 "I<si_signo>, I<si_errno> and I<si_code> are defined for all signals. "
3944 "(I<si_errno> is generally unused on Linux.) The rest of the struct may be a "
3945 "union, so that one should read only the fields that are meaningful for the "
3950 #: build/C/man2/sigaction.2:324
3952 "Signals sent with B<kill>(2) and B<sigqueue>(3) fill in I<si_pid> and "
3953 "I<si_uid>. In addition, signals sent with B<sigqueue>(3) fill in I<si_int> "
3954 "and I<si_ptr> with the values specified by the sender of the signal; see "
3955 "B<sigqueue>(3) for more details."
3959 #: build/C/man2/sigaction.2:340
3961 "Signals sent by POSIX.1b timers (since Linux 2.6) fill in I<si_overrun> and "
3962 "I<si_timerid>. The I<si_timerid> field is an internal ID used by the kernel "
3963 "to identify the timer; it is not the same as the timer ID returned by "
3964 "B<timer_create>(2). The I<si_overrun> field is the timer overrun count; "
3965 "this is the same information as is obtained by a call to "
3966 "B<timer_getoverrun>(2). These fields are nonstandard Linux extensions."
3970 #: build/C/man2/sigaction.2:355
3972 "Signals sent for message queue notification (see the description of "
3973 "B<SIGEV_SIGNAL> in B<mq_notify>(3)) fill in I<si_int>/I<si_ptr>, with the "
3974 "I<sigev_value> supplied to B<mq_notify>(3); I<si_pid>, with the process ID "
3975 "of the message sender; and I<si_uid>, with the real user ID of the message "
3980 #. When si_utime and si_stime where originally implemented, the
3981 #. measurement unit was HZ, which was the same as clock ticks
3982 #. (sysconf(_SC_CLK_TCK)). In 2.6, HZ became configurable, and
3983 #. was *still* used as the unit to return the info these fields,
3984 #. with the result that the field values depended on the the
3985 #. configured HZ. Of course, the should have been measured in
3986 #. USER_HZ instead, so that sysconf(_SC_CLK_TCK) could be used to
3987 #. convert to seconds. I have a queued patch to fix this:
3988 #. http://thread.gmane.org/gmane.linux.kernel/698061/ .
3989 #. This patch made it into 2.6.27.
3990 #. But note that these fields still don't return the times of
3991 #. waited-for children (as is done by getrusage() and times()
3992 #. and wait4()). Solaris 8 does include child times.
3994 #: build/C/man2/sigaction.2:402
3996 "B<SIGCHLD> fills in I<si_pid>, I<si_uid>, I<si_status>, I<si_utime>, and "
3997 "I<si_stime>, providing information about the child. The I<si_pid> field is "
3998 "the process ID of the child; I<si_uid> is the child's real user ID. The "
3999 "I<si_status> field contains the exit status of the child (if I<si_code> is "
4000 "B<CLD_EXITED>), or the signal number that caused the process to change "
4001 "state. The I<si_utime> and I<si_stime> contain the user and system CPU time "
4002 "used by the child process; these fields do not include the times used by "
4003 "waited-for children (unlike B<getrusage>(2) and B<times>(2)). In kernels "
4004 "up to 2.6, and since 2.6.27, these fields report CPU time in units of "
4005 "I<sysconf(_SC_CLK_TCK)>. In 2.6 kernels before 2.6.27, a bug meant that "
4006 "these fields reported time in units of the (configurable) system jiffy (see "
4010 #. FIXME . SIGTRAP also sets the following for ptrace_notify() ?
4011 #. info.si_code = exit_code;
4012 #. info.si_pid = task_pid_vnr(current);
4013 #. info.si_uid = current_uid(); /* Real UID */
4015 #: build/C/man2/sigaction.2:438
4017 "B<SIGILL>, B<SIGFPE>, B<SIGSEGV>, B<SIGBUS>, and B<SIGTRAP> fill in "
4018 "I<si_addr> with the address of the fault. On some architectures, these "
4019 "signals also fill in the I<si_trapno> field. Some suberrors of B<SIGBUS>, "
4020 "in particular B<BUS_MCEERR_AO> and B<BUS_MCEERR_AR>, also fill in "
4021 "I<si_addr_lsb>. This field indicates the least significant bit of the "
4022 "reported address and therefore the extent of the corruption. For example, "
4023 "if a full page was corrupted, I<si_addr_lsb> contains "
4024 "I<log2(sysconf(_SC_PAGESIZE))>. B<BUS_MCERR_*> and I<si_addr_lsb> are "
4025 "Linux-specific extensions."
4029 #: build/C/man2/sigaction.2:452
4031 "B<SIGIO>/B<SIGPOLL> (the two names are synonyms on Linux) fills in "
4032 "I<si_band> and I<si_fd>. The I<si_band> event is a bit mask containing the "
4033 "same values as are filled in the I<revents> field by B<poll>(2). The "
4034 "I<si_fd> field indicates the file descriptor for which the I/O event "
4039 #: build/C/man2/sigaction.2:459
4041 "I<si_code> is a value (not a bit mask) indicating why this signal was "
4042 "sent. The following list shows the values which can be placed in I<si_code> "
4043 "for any signal, along with reason that the signal was generated."
4047 #: build/C/man2/sigaction.2:460
4053 #: build/C/man2/sigaction.2:463 build/C/man7/signal.7:111
4059 #: build/C/man2/sigaction.2:463
4061 msgid "B<SI_KERNEL>"
4065 #: build/C/man2/sigaction.2:466
4066 msgid "Sent by the kernel."
4070 #: build/C/man2/sigaction.2:466
4076 #: build/C/man2/sigaction.2:469 build/C/man7/signal.7:128
4078 msgid "B<sigqueue>(3)"
4082 #: build/C/man2/sigaction.2:469
4088 #: build/C/man2/sigaction.2:472
4089 msgid "POSIX timer expired"
4093 #: build/C/man2/sigaction.2:472
4099 #: build/C/man2/sigaction.2:476
4100 msgid "POSIX message queue state changed (since Linux 2.6.6); see B<mq_notify>(3)"
4104 #: build/C/man2/sigaction.2:476
4106 msgid "B<SI_ASYNCIO>"
4110 #: build/C/man2/sigaction.2:479
4111 msgid "AIO completed"
4115 #: build/C/man2/sigaction.2:479
4121 #: build/C/man2/sigaction.2:488
4123 "Queued B<SIGIO> (only in kernels up to Linux 2.2; from Linux 2.4 onward "
4124 "B<SIGIO>/B<SIGPOLL> fills in I<si_code> as described below)."
4128 #: build/C/man2/sigaction.2:488
4133 #. SI_DETHREAD is defined in 2.6.9 sources, but isn't implemented
4134 #. It appears to have been an idea that was tried during 2.5.6
4135 #. through to 2.5.24 and then was backed out.
4137 #: build/C/man2/sigaction.2:497
4138 msgid "B<tkill>(2) or B<tgkill>(2) (since Linux 2.4.19)"
4142 #: build/C/man2/sigaction.2:504
4143 msgid "The following values can be placed in I<si_code> for a B<SIGILL> signal:"
4147 #: build/C/man2/sigaction.2:505
4149 msgid "B<ILL_ILLOPC>"
4153 #: build/C/man2/sigaction.2:508
4154 msgid "illegal opcode"
4158 #: build/C/man2/sigaction.2:508
4160 msgid "B<ILL_ILLOPN>"
4164 #: build/C/man2/sigaction.2:511
4165 msgid "illegal operand"
4169 #: build/C/man2/sigaction.2:511
4171 msgid "B<ILL_ILLADR>"
4175 #: build/C/man2/sigaction.2:514
4176 msgid "illegal addressing mode"
4180 #: build/C/man2/sigaction.2:514
4182 msgid "B<ILL_ILLTRP>"
4186 #: build/C/man2/sigaction.2:517
4187 msgid "illegal trap"
4191 #: build/C/man2/sigaction.2:517
4193 msgid "B<ILL_PRVOPC>"
4197 #: build/C/man2/sigaction.2:520
4198 msgid "privileged opcode"
4202 #: build/C/man2/sigaction.2:520
4204 msgid "B<ILL_PRVREG>"
4208 #: build/C/man2/sigaction.2:523
4209 msgid "privileged register"
4213 #: build/C/man2/sigaction.2:523
4215 msgid "B<ILL_COPROC>"
4219 #: build/C/man2/sigaction.2:526
4220 msgid "coprocessor error"
4224 #: build/C/man2/sigaction.2:526
4226 msgid "B<ILL_BADSTK>"
4230 #: build/C/man2/sigaction.2:529
4231 msgid "internal stack error"
4235 #: build/C/man2/sigaction.2:536
4236 msgid "The following values can be placed in I<si_code> for a B<SIGFPE> signal:"
4240 #: build/C/man2/sigaction.2:537
4242 msgid "B<FPE_INTDIV>"
4246 #: build/C/man2/sigaction.2:540
4247 msgid "integer divide by zero"
4251 #: build/C/man2/sigaction.2:540
4253 msgid "B<FPE_INTOVF>"
4257 #: build/C/man2/sigaction.2:543
4258 msgid "integer overflow"
4262 #: build/C/man2/sigaction.2:543
4264 msgid "B<FPE_FLTDIV>"
4268 #: build/C/man2/sigaction.2:546
4269 msgid "floating-point divide by zero"
4273 #: build/C/man2/sigaction.2:546
4275 msgid "B<FPE_FLTOVF>"
4279 #: build/C/man2/sigaction.2:549
4280 msgid "floating-point overflow"
4284 #: build/C/man2/sigaction.2:549
4286 msgid "B<FPE_FLTUND>"
4290 #: build/C/man2/sigaction.2:552
4291 msgid "floating-point underflow"
4295 #: build/C/man2/sigaction.2:552
4297 msgid "B<FPE_FLTRES>"
4301 #: build/C/man2/sigaction.2:555
4302 msgid "floating-point inexact result"
4306 #: build/C/man2/sigaction.2:555
4308 msgid "B<FPE_FLTINV>"
4312 #: build/C/man2/sigaction.2:558
4313 msgid "floating-point invalid operation"
4317 #: build/C/man2/sigaction.2:558
4319 msgid "B<FPE_FLTSUB>"
4323 #: build/C/man2/sigaction.2:561
4324 msgid "subscript out of range"
4328 #: build/C/man2/sigaction.2:568
4329 msgid "The following values can be placed in I<si_code> for a B<SIGSEGV> signal:"
4333 #: build/C/man2/sigaction.2:569
4335 msgid "B<SEGV_MAPERR>"
4339 #: build/C/man2/sigaction.2:572
4340 msgid "address not mapped to object"
4344 #: build/C/man2/sigaction.2:572
4346 msgid "B<SEGV_ACCERR>"
4350 #: build/C/man2/sigaction.2:575
4351 msgid "invalid permissions for mapped object"
4355 #: build/C/man2/sigaction.2:582
4356 msgid "The following values can be placed in I<si_code> for a B<SIGBUS> signal:"
4360 #: build/C/man2/sigaction.2:583
4362 msgid "B<BUS_ADRALN>"
4366 #: build/C/man2/sigaction.2:586
4367 msgid "invalid address alignment"
4371 #: build/C/man2/sigaction.2:586
4373 msgid "B<BUS_ADRERR>"
4377 #: build/C/man2/sigaction.2:589
4378 msgid "nonexistent physical address"
4382 #: build/C/man2/sigaction.2:589
4384 msgid "B<BUS_OBJERR>"
4388 #: build/C/man2/sigaction.2:592
4389 msgid "object-specific hardware error"
4393 #: build/C/man2/sigaction.2:592
4395 msgid "B<BUS_MCEERR_AR> (since Linux 2.6.32)"
4399 #: build/C/man2/sigaction.2:595
4400 msgid "Hardware memory error consumed on a machine check; action required."
4404 #: build/C/man2/sigaction.2:595
4406 msgid "B<BUS_MCEERR_AO> (since Linux 2.6.32)"
4410 #: build/C/man2/sigaction.2:598
4411 msgid "Hardware memory error detected in process but not consumed; action optional."
4415 #: build/C/man2/sigaction.2:605
4416 msgid "The following values can be placed in I<si_code> for a B<SIGTRAP> signal:"
4420 #: build/C/man2/sigaction.2:606
4422 msgid "B<TRAP_BRKPT>"
4426 #: build/C/man2/sigaction.2:609
4427 msgid "process breakpoint"
4431 #: build/C/man2/sigaction.2:609
4433 msgid "B<TRAP_TRACE>"
4437 #: build/C/man2/sigaction.2:612
4438 msgid "process trace trap"
4442 #: build/C/man2/sigaction.2:612
4444 msgid "B<TRAP_BRANCH> (since Linux 2.4)"
4448 #: build/C/man2/sigaction.2:615
4449 msgid "process taken branch trap"
4453 #: build/C/man2/sigaction.2:615
4455 msgid "B<TRAP_HWBKPT> (since Linux 2.4)"
4459 #: build/C/man2/sigaction.2:618
4460 msgid "hardware breakpoint/watchpoint"
4464 #: build/C/man2/sigaction.2:625
4465 msgid "The following values can be placed in I<si_code> for a B<SIGCHLD> signal:"
4469 #: build/C/man2/sigaction.2:626
4471 msgid "B<CLD_EXITED>"
4475 #: build/C/man2/sigaction.2:629
4476 msgid "child has exited"
4480 #: build/C/man2/sigaction.2:629
4482 msgid "B<CLD_KILLED>"
4486 #: build/C/man2/sigaction.2:632
4487 msgid "child was killed"
4491 #: build/C/man2/sigaction.2:632
4493 msgid "B<CLD_DUMPED>"
4497 #: build/C/man2/sigaction.2:635
4498 msgid "child terminated abnormally"
4502 #: build/C/man2/sigaction.2:635
4504 msgid "B<CLD_TRAPPED>"
4508 #: build/C/man2/sigaction.2:638
4509 msgid "traced child has trapped"
4513 #: build/C/man2/sigaction.2:638
4515 msgid "B<CLD_STOPPED>"
4519 #: build/C/man2/sigaction.2:641
4520 msgid "child has stopped"
4524 #: build/C/man2/sigaction.2:641
4526 msgid "B<CLD_CONTINUED>"
4530 #: build/C/man2/sigaction.2:644
4531 msgid "stopped child has continued (since Linux 2.6.9)"
4535 #: build/C/man2/sigaction.2:651
4537 "The following values can be placed in I<si_code> for a B<SIGIO>/B<SIGPOLL> "
4542 #: build/C/man2/sigaction.2:652
4548 #: build/C/man2/sigaction.2:655
4549 msgid "data input available"
4553 #: build/C/man2/sigaction.2:655
4559 #: build/C/man2/sigaction.2:658
4560 msgid "output buffers available"
4564 #: build/C/man2/sigaction.2:658
4570 #: build/C/man2/sigaction.2:661
4571 msgid "input message available"
4575 #: build/C/man2/sigaction.2:661
4581 #: build/C/man2/sigaction.2:664
4586 #: build/C/man2/sigaction.2:664
4592 #: build/C/man2/sigaction.2:667
4593 msgid "high priority input available"
4597 #: build/C/man2/sigaction.2:667
4603 #: build/C/man2/sigaction.2:670
4604 msgid "device disconnected"
4608 #: build/C/man2/sigaction.2:676
4610 "B<sigaction>() returns 0 on success; on error, -1 is returned, and I<errno> "
4611 "is set to indicate the error."
4615 #: build/C/man2/sigaction.2:681
4617 "I<act> or I<oldact> points to memory which is not a valid part of the "
4618 "process address space."
4622 #: build/C/man2/sigaction.2:688
4624 "An invalid signal was specified. This will also be generated if an attempt "
4625 "is made to change the action for B<SIGKILL> or B<SIGSTOP>, which cannot be "
4626 "caught or ignored."
4629 #. SVr4 does not document the EINTR condition.
4631 #: build/C/man2/sigaction.2:691
4632 msgid "POSIX.1-2001, SVr4."
4636 #: build/C/man2/sigaction.2:699 build/C/man7/signal.7:105
4638 "A child created via B<fork>(2) inherits a copy of its parent's signal "
4639 "dispositions. During an B<execve>(2), the dispositions of handled signals "
4640 "are reset to the default; the dispositions of ignored signals are left "
4645 #: build/C/man2/sigaction.2:717 build/C/man2/signal.2:134
4647 "According to POSIX, the behavior of a process is undefined after it ignores "
4648 "a B<SIGFPE>, B<SIGILL>, or B<SIGSEGV> signal that was not generated by "
4649 "B<kill>(2) or B<raise>(3). Integer division by zero has undefined result. "
4650 "On some architectures it will generate a B<SIGFPE> signal. (Also dividing "
4651 "the most negative integer by -1 may generate B<SIGFPE>.) Ignoring this "
4652 "signal might lead to an endless loop."
4656 #: build/C/man2/sigaction.2:734
4658 "POSIX.1-1990 disallowed setting the action for B<SIGCHLD> to B<SIG_IGN>. "
4659 "POSIX.1-2001 allows this possibility, so that ignoring B<SIGCHLD> can be "
4660 "used to prevent the creation of zombies (see B<wait>(2)). Nevertheless, the "
4661 "historical BSD and System\\ V behaviors for ignoring B<SIGCHLD> differ, so "
4662 "that the only completely portable method of ensuring that terminated "
4663 "children do not become zombies is to catch the B<SIGCHLD> signal and perform "
4664 "a B<wait>(2) or similar."
4668 #: build/C/man2/sigaction.2:747
4670 "POSIX.1-1990 specified only B<SA_NOCLDSTOP>. POSIX.1-2001 added "
4671 "B<SA_NOCLDWAIT>, B<SA_RESETHAND>, B<SA_NODEFER>, and B<SA_SIGINFO>. Use of "
4672 "these latter values in I<sa_flags> may be less portable in applications "
4673 "intended for older UNIX implementations."
4677 #: build/C/man2/sigaction.2:751
4678 msgid "The B<SA_RESETHAND> flag is compatible with the SVr4 flag of the same name."
4682 #: build/C/man2/sigaction.2:761
4684 "The B<SA_NODEFER> flag is compatible with the SVr4 flag of the same name "
4685 "under kernels 1.3.9 and newer. On older kernels the Linux implementation "
4686 "allowed the receipt of any signal, not just the one we are installing "
4687 "(effectively overriding any I<sa_mask> settings)."
4691 #: build/C/man2/sigaction.2:767
4693 "B<sigaction>() can be called with a NULL second argument to query the "
4694 "current signal handler. It can also be used to check whether a given signal "
4695 "is valid for the current machine by calling it with NULL second and third "
4700 #: build/C/man2/sigaction.2:773
4702 "It is not possible to block B<SIGKILL> or B<SIGSTOP> (by specifying them in "
4703 "I<sa_mask>). Attempts to do so are silently ignored."
4707 #: build/C/man2/sigaction.2:777 build/C/man2/sigpending.2:70 build/C/man2/sigprocmask.2:144 build/C/man2/sigsuspend.2:108
4708 msgid "See B<sigsetops>(3) for details on manipulating signal sets."
4712 #: build/C/man2/sigaction.2:782
4714 "See B<signal>(7) for a list of the async-signal-safe functions that can be "
4715 "safely called inside from inside a signal handler."
4719 #: build/C/man2/sigaction.2:782
4721 msgid "Undocumented"
4725 #: build/C/man2/sigaction.2:792
4727 "Before the introduction of B<SA_SIGINFO> it was also possible to get some "
4728 "additional information, namely by using a I<sa_handler> with second argument "
4729 "of type I<struct sigcontext>. See the relevant Linux kernel sources for "
4730 "details. This use is obsolete now."
4734 #: build/C/man2/sigaction.2:801
4736 "In kernels up to and including 2.6.13, specifying B<SA_NODEFER> in "
4737 "I<sa_flags> prevents not only the delivered signal from being masked during "
4738 "execution of the handler, but also the signals specified in I<sa_mask>. "
4739 "This bug was fixed in kernel 2.6.14."
4743 #: build/C/man2/sigaction.2:804
4744 msgid "See B<mprotect>(2)."
4748 #: build/C/man2/sigaction.2:825
4750 "B<kill>(1), B<kill>(2), B<killpg>(2), B<pause>(2), B<restart_syscall>(2), "
4751 "B<sigaltstack>(2), B<signal>(2), B<signalfd>(2), B<sigpending>(2), "
4752 "B<sigreturn>(2), B<sigprocmask>(2), B<sigsuspend>(2), B<wait>(2), "
4753 "B<raise>(3), B<siginterrupt>(3), B<sigqueue>(3), B<sigsetops>(3), "
4754 "B<sigvec>(3), B<core>(5), B<signal>(7)"
4758 #: build/C/man2/sigaltstack.2:27
4764 #: build/C/man2/sigaltstack.2:27
4770 #: build/C/man2/sigaltstack.2:30
4771 msgid "sigaltstack - set and/or get signal stack context"
4775 #: build/C/man2/sigaltstack.2:34
4776 msgid "B<int sigaltstack(const stack_t *>I<ss>B<, stack_t *>I<oss>B<);>"
4780 #: build/C/man2/sigaltstack.2:41
4781 msgid "B<sigaltstack>():"
4785 #: build/C/man2/sigaltstack.2:48 build/C/man3/siginterrupt.3:53 build/C/man2/wait.2:80
4786 msgid "|| /* Since glibc 2.12: */ _POSIX_C_SOURCE\\ E<gt>=\\ 200809L"
4790 #: build/C/man2/sigaltstack.2:60
4792 "B<sigaltstack>() allows a process to define a new alternate signal stack "
4793 "and/or retrieve the state of an existing alternate signal stack. An "
4794 "alternate signal stack is used during the execution of a signal handler if "
4795 "the establishment of that handler (see B<sigaction>(2)) requested it."
4799 #: build/C/man2/sigaltstack.2:63
4801 "The normal sequence of events for using an alternate signal stack is the "
4806 #: build/C/man2/sigaltstack.2:63 build/C/man7/signal.7:387
4812 #: build/C/man2/sigaltstack.2:67
4813 msgid "Allocate an area of memory to be used for the alternate signal stack."
4817 #: build/C/man2/sigaltstack.2:67 build/C/man7/signal.7:391
4823 #: build/C/man2/sigaltstack.2:73
4825 "Use B<sigaltstack>() to inform the system of the existence and location of "
4826 "the alternate signal stack."
4830 #: build/C/man2/sigaltstack.2:73 build/C/man7/signal.7:411
4836 #: build/C/man2/sigaltstack.2:80
4838 "When establishing a signal handler using B<sigaction>(2), inform the system "
4839 "that the signal handler should be executed on the alternate signal stack by "
4840 "specifying the B<SA_ONSTACK> flag."
4844 #: build/C/man2/sigaltstack.2:88
4846 "The I<ss> argument is used to specify a new alternate signal stack, while "
4847 "the I<oss> argument is used to retrieve information about the currently "
4848 "established signal stack. If we are interested in performing just one of "
4849 "these tasks, then the other argument can be specified as NULL. Each of "
4850 "these arguments is a structure of the following type:"
4854 #: build/C/man2/sigaltstack.2:96
4857 "typedef struct {\n"
4858 " void *ss_sp; /* Base address of stack */\n"
4859 " int ss_flags; /* Flags */\n"
4860 " size_t ss_size; /* Number of bytes in stack */\n"
4865 #: build/C/man2/sigaltstack.2:107
4867 "To establish a new alternate signal stack, I<ss.ss_flags> is set to zero, "
4868 "and I<ss.ss_sp> and I<ss.ss_size> specify the starting address and size of "
4869 "the stack. The constant B<SIGSTKSZ> is defined to be large enough to cover "
4870 "the usual size requirements for an alternate signal stack, and the constant "
4871 "B<MINSIGSTKSZ> defines the minimum size required to execute a signal "
4876 #: build/C/man2/sigaltstack.2:111
4878 "When a signal handler is invoked on the alternate stack, the kernel "
4879 "automatically aligns the address given in I<ss.ss_sp> to a suitable address "
4880 "boundary for the underlying hardware architecture."
4884 #: build/C/man2/sigaltstack.2:116
4886 "To disable an existing stack, specify I<ss.ss_flags> as B<SS_DISABLE>. In "
4887 "this case, the remaining fields in I<ss> are ignored."
4891 #: build/C/man2/sigaltstack.2:124
4893 "If I<oss> is not NULL, then it is used to return information about the "
4894 "alternate signal stack which was in effect prior to the call to "
4895 "B<sigaltstack>(). The I<oss.ss_sp> and I<oss.ss_size> fields return the "
4896 "starting address and size of that stack. The I<oss.ss_flags> may return "
4897 "either of the following values:"
4901 #: build/C/man2/sigaltstack.2:124
4903 msgid "B<SS_ONSTACK>"
4907 #: build/C/man2/sigaltstack.2:130
4909 "The process is currently executing on the alternate signal stack. (Note "
4910 "that it is not possible to change the alternate signal stack if the process "
4911 "is currently executing on it.)"
4915 #: build/C/man2/sigaltstack.2:130
4917 msgid "B<SS_DISABLE>"
4921 #: build/C/man2/sigaltstack.2:133
4922 msgid "The alternate signal stack is currently disabled."
4926 #: build/C/man2/sigaltstack.2:137
4928 "B<sigaltstack>() returns 0 on success, or -1 on failure with I<errno> set "
4929 "to indicate the error."
4933 #: build/C/man2/sigaltstack.2:142
4935 "Either I<ss> or I<oss> is not NULL and points to an area outside of the "
4936 "process's address space."
4940 #: build/C/man2/sigaltstack.2:147
4942 "I<ss> is not NULL and the I<ss_flags> field contains a nonzero value other "
4943 "than B<SS_DISABLE>."
4947 #: build/C/man2/sigaltstack.2:153
4949 "The specified size of the new alternate signal stack I<ss.ss_size> was less "
4954 #: build/C/man2/sigaltstack.2:158
4956 "An attempt was made to change the alternate signal stack while it was active "
4957 "(i.e., the process was already executing on the current alternate signal "
4962 #: build/C/man2/sigaltstack.2:160
4963 msgid "SUSv2, SVr4, POSIX.1-2001."
4967 #: build/C/man2/sigaltstack.2:168
4969 "The most common usage of an alternate signal stack is to handle the "
4970 "B<SIGSEGV> signal that is generated if the space available for the normal "
4971 "process stack is exhausted: in this case, a signal handler for B<SIGSEGV> "
4972 "cannot be invoked on the process stack; if we wish to handle it, we must use "
4973 "an alternate signal stack."
4977 #: build/C/man2/sigaltstack.2:178
4979 "Establishing an alternate signal stack is useful if a process expects that "
4980 "it may exhaust its standard stack. This may occur, for example, because the "
4981 "stack grows so large that it encounters the upwardly growing heap, or it "
4982 "reaches a limit established by a call to B<setrlimit(RLIMIT_STACK, &rlim)>. "
4983 "If the standard stack is exhausted, the kernel sends the process a "
4984 "B<SIGSEGV> signal. In these circumstances the only way to catch this signal "
4985 "is on an alternate signal stack."
4989 #: build/C/man2/sigaltstack.2:184
4991 "On most hardware architectures supported by Linux, stacks grow downward. "
4992 "B<sigaltstack>() automatically takes account of the direction of stack "
4997 #: build/C/man2/sigaltstack.2:193
4999 "Functions called from a signal handler executing on an alternate signal "
5000 "stack will also use the alternate signal stack. (This also applies to any "
5001 "handlers invoked for other signals while the process is executing on the "
5002 "alternate signal stack.) Unlike the standard stack, the system does not "
5003 "automatically extend the alternate signal stack. Exceeding the allocated "
5004 "size of the alternate signal stack will lead to unpredictable results."
5008 #: build/C/man2/sigaltstack.2:201
5010 "A successful call to B<execve>(2) removes any existing alternate signal "
5011 "stack. A child process created via B<fork>(2) inherits a copy of its "
5012 "parent's alternate signal stack settings."
5016 #: build/C/man2/sigaltstack.2:210
5018 "B<sigaltstack>() supersedes the older B<sigstack>() call. For backward "
5019 "compatibility, glibc also provides B<sigstack>(). All new applications "
5020 "should be written using B<sigaltstack>()."
5024 #: build/C/man2/sigaltstack.2:210 build/C/man3/sigpause.3:66
5030 #: build/C/man2/sigaltstack.2:217
5032 "4.2BSD had a B<sigstack>() system call. It used a slightly different "
5033 "struct, and had the major disadvantage that the caller had to know the "
5034 "direction of stack growth."
5038 #: build/C/man2/sigaltstack.2:220
5039 msgid "The following code segment demonstrates the use of B<sigaltstack>():"
5043 #: build/C/man2/sigaltstack.2:224
5045 msgid "stack_t ss;\n"
5049 #: build/C/man2/sigaltstack.2:232
5052 "ss.ss_sp = malloc(SIGSTKSZ);\n"
5053 "if (ss.ss_sp == NULL)\n"
5054 " /* Handle error */;\n"
5055 "ss.ss_size = SIGSTKSZ;\n"
5056 "ss.ss_flags = 0;\n"
5057 "if (sigaltstack(&ss, NULL) == -1)\n"
5058 " /* Handle error */;\n"
5062 #: build/C/man2/sigaltstack.2:241
5064 "B<execve>(2), B<setrlimit>(2), B<sigaction>(2), B<siglongjmp>(3), "
5065 "B<sigsetjmp>(3), B<signal>(7)"
5069 #: build/C/man7/sigevent.7:26
5075 #: build/C/man7/sigevent.7:26
5081 #: build/C/man7/sigevent.7:29
5082 msgid "sigevent - structure for notification from asynchronous routines"
5086 #: build/C/man7/sigevent.7:36
5089 "union sigval { /* Data passed with notification */\n"
5090 " int sival_int; /* Integer value */\n"
5091 " void *sival_ptr; /* Pointer value */\n"
5096 #: build/C/man7/sigevent.7:51
5099 "struct sigevent {\n"
5100 " int sigev_notify; /* Notification method */\n"
5101 " int sigev_signo; /* Notification signal */\n"
5102 " union sigval sigev_value; /* Data passed with\n"
5103 " notification */\n"
5104 " void (*sigev_notify_function) (union sigval);\n"
5105 " /* Function used for thread\n"
5106 " notification (SIGEV_THREAD) */\n"
5107 " void *sigev_notify_attributes;\n"
5108 " /* Attributes for notification thread\n"
5109 " (SIGEV_THREAD) */\n"
5110 " pid_t sigev_notify_thread_id;\n"
5111 " /* ID of thread to signal (SIGEV_THREAD_ID) */\n"
5116 #: build/C/man7/sigevent.7:60
5118 "The I<sigevent> structure is used by various APIs to describe the way a "
5119 "process is to be notified about an event (e.g., completion of an "
5120 "asynchronous request, expiration of a timer, or the arrival of a message)."
5124 #: build/C/man7/sigevent.7:68
5126 "The definition shown in the SYNOPSIS is approximate: some of the fields in "
5127 "the I<sigevent> structure may be defined as part of a union. Programs "
5128 "should employ only those fields relevant to the value specified in "
5133 #: build/C/man7/sigevent.7:73
5135 "The I<sigev_notify> field specifies how notification is to be performed. "
5136 "This field can have one of the following values:"
5140 #: build/C/man7/sigevent.7:73 build/C/man2/timer_create.2:109
5142 msgid "B<SIGEV_NONE>"
5146 #: build/C/man7/sigevent.7:76
5147 msgid "A \"null\" notification: don't do anything when the event occurs."
5151 #: build/C/man7/sigevent.7:76 build/C/man2/timer_create.2:114
5153 msgid "B<SIGEV_SIGNAL>"
5157 #: build/C/man7/sigevent.7:80
5158 msgid "Notify the process by sending the signal specified in I<sigev_signo>."
5162 #: build/C/man7/sigevent.7:87
5164 "If the signal is caught with a signal handler that was registered using the "
5165 "B<sigaction>(2) B<SA_SIGINFO> flag, then the following fields are set in "
5166 "the I<siginfo_t> structure that is passed as the second argument of the "
5171 #: build/C/man7/sigevent.7:92
5173 "This field is set to a value that depends on the API delivering the "
5178 #: build/C/man7/sigevent.7:92 build/C/man2/wait.2:302
5184 #: build/C/man7/sigevent.7:96
5186 "This field is set to the signal number (i.e., the same value as in "
5191 #: build/C/man7/sigevent.7:100
5192 msgid "This field is set to the value specified in I<sigev_value>."
5196 #: build/C/man7/sigevent.7:105
5198 "Depending on the API, other fields may also be set in the I<siginfo_t> "
5203 #: build/C/man7/sigevent.7:108
5205 "The same information is also available if the signal is accepted using "
5206 "B<sigwaitinfo>(2)."
5210 #: build/C/man7/sigevent.7:108 build/C/man2/timer_create.2:132
5212 msgid "B<SIGEV_THREAD>"
5216 #: build/C/man7/sigevent.7:125
5218 "Notify the process by invoking I<sigev_notify_function> \"as if\" it were "
5219 "the start function of a new thread. (Among the implementation possibilities "
5220 "here are that each timer notification could result in the creation of a new "
5221 "thread, or that a single thread is created to receive all notifications.) "
5222 "The function is invoked with I<sigev_value> as its sole argument. If "
5223 "I<sigev_notify_attributes> is not NULL, it should point to a "
5224 "I<pthread_attr_t> structure that defines attributes for the new thread (see "
5225 "B<pthread_attr_init>(3))."
5229 #: build/C/man7/sigevent.7:125 build/C/man2/timer_create.2:140
5231 msgid "B<SIGEV_THREAD_ID> (Linux-specific)"
5234 #. | SIGEV_SIGNAL vs not?
5236 #: build/C/man7/sigevent.7:130
5237 msgid "Currently used only by POSIX timers; see B<timer_create>(2)."
5241 #: build/C/man7/sigevent.7:132 build/C/man2/sigpending.2:66 build/C/man2/sigprocmask.2:114 build/C/man3/sigqueue.3:121 build/C/man3/sigsetops.3:147 build/C/man2/sigsuspend.2:86 build/C/man3/sigwait.3:87 build/C/man2/sigwaitinfo.2:135 build/C/man2/timer_create.2:197 build/C/man2/timer_delete.2:69 build/C/man2/timer_getoverrun.2:99 build/C/man2/timer_settime.2:209
5242 msgid "POSIX.1-2001."
5246 #: build/C/man7/sigevent.7:142
5248 "B<timer_create>(2), B<aio_fsync>(3), B<aio_read>(3), B<aio_write>(3), "
5249 "B<getaddrinfo_a>(3), B<lio_listio>(3), B<mq_notify>(3), B<aio>(7), "
5254 #: build/C/man3/siginterrupt.3:31
5256 msgid "SIGINTERRUPT"
5260 #: build/C/man3/siginterrupt.3:31
5266 #: build/C/man3/siginterrupt.3:34
5267 msgid "siginterrupt - allow signals to interrupt system calls"
5271 #: build/C/man3/siginterrupt.3:39
5273 msgid "B<int siginterrupt(int >I<sig>B<, int >I<flag>B<);>\n"
5277 #: build/C/man3/siginterrupt.3:47
5278 msgid "B<siginterrupt>():"
5282 #: build/C/man3/siginterrupt.3:64
5284 "The B<siginterrupt>() function changes the restart behavior when a system "
5285 "call is interrupted by the signal I<sig>. If the I<flag> argument is false "
5286 "(0), then system calls will be restarted if interrupted by the specified "
5287 "signal I<sig>. This is the default behavior in Linux."
5291 #: build/C/man3/siginterrupt.3:69
5293 "If the I<flag> argument is true (1) and no data has been transferred, then a "
5294 "system call interrupted by the signal I<sig> will return -1 and I<errno> "
5295 "will be set to B<EINTR>."
5299 #: build/C/man3/siginterrupt.3:73
5301 "If the I<flag> argument is true (1) and data transfer has started, then the "
5302 "system call will be interrupted and will return the actual amount of data "
5307 #: build/C/man3/siginterrupt.3:83
5309 "The B<siginterrupt>() function returns 0 on success. It returns -1 if the "
5310 "signal number I<sig> is invalid, with I<errno> set to indicate the cause of "
5315 #: build/C/man3/siginterrupt.3:87
5316 msgid "The specified signal number is invalid."
5320 #: build/C/man3/siginterrupt.3:93
5322 "The B<siginterrupt>() function uses a global variable that is not "
5323 "protected, so it is not thread-safe."
5327 #: build/C/man3/siginterrupt.3:102
5329 "4.3BSD, POSIX.1-2001. POSIX.1-2008 marks B<siginterrupt>() as obsolete, "
5330 "recommending the use of B<sigaction>(2) with the B<SA_RESTART> flag "
5335 #: build/C/man3/siginterrupt.3:104
5336 msgid "B<signal>(2)"
5340 #: build/C/man2/signal.2:36 build/C/man7/signal.7:46
5346 #: build/C/man2/signal.2:36 build/C/man3/sigpause.3:25 build/C/man2/sigwaitinfo.2:25 build/C/man2/timer_create.2:33 build/C/man2/wait.2:49
5352 #: build/C/man2/signal.2:39
5353 msgid "signal - ANSI C signal handling"
5357 #: build/C/man2/signal.2:45
5358 msgid "B<sighandler_t signal(int >I<signum>B<, sighandler_t >I<handler>B<);>"
5362 #: build/C/man2/signal.2:54
5364 "The behavior of B<signal>() varies across UNIX versions, and has also "
5365 "varied historically across different versions of Linux. B<Avoid its use>: "
5366 "use B<sigaction>(2) instead. See I<Portability> below."
5370 #: build/C/man2/signal.2:64
5372 "B<signal>() sets the disposition of the signal I<signum> to I<handler>, "
5373 "which is either B<SIG_IGN>, B<SIG_DFL>, or the address of a "
5374 "programmer-defined function (a \"signal handler\")."
5378 #: build/C/man2/signal.2:68
5380 "If the signal I<signum> is delivered to the process, then one of the "
5381 "following happens:"
5385 #: build/C/man2/signal.2:73
5386 msgid "If the disposition is set to B<SIG_IGN>, then the signal is ignored."
5390 #: build/C/man2/signal.2:80
5392 "If the disposition is set to B<SIG_DFL>, then the default action associated "
5393 "with the signal (see B<signal>(7)) occurs."
5397 #: build/C/man2/signal.2:91
5399 "If the disposition is set to a function, then first either the disposition "
5400 "is reset to B<SIG_DFL>, or the signal is blocked (see I<Portability> below), "
5401 "and then I<handler> is called with argument I<signum>. If invocation of the "
5402 "handler caused the signal to be blocked, then the signal is unblocked upon "
5403 "return from the handler."
5407 #: build/C/man2/signal.2:97
5408 msgid "The signals B<SIGKILL> and B<SIGSTOP> cannot be caught or ignored."
5412 #: build/C/man2/signal.2:105
5414 "B<signal>() returns the previous value of the signal handler, or B<SIG_ERR> "
5415 "on error. In the event of an error, I<errno> is set to indicate the cause."
5419 #: build/C/man2/signal.2:110
5420 msgid "I<signum> is invalid."
5424 #: build/C/man2/signal.2:116
5425 msgid "The effects of B<signal>() in a multithreaded process are unspecified."
5429 #: build/C/man2/signal.2:141
5431 "See B<sigaction>(2) for details on what happens when B<SIGCHLD> is set to "
5436 #: build/C/man2/signal.2:146
5438 "See B<signal>(7) for a list of the async-signal-safe functions that can be "
5439 "safely called from inside a signal handler."
5442 #. libc4 and libc5 define
5443 #. .IR SignalHandler ;
5445 #: build/C/man2/signal.2:162
5447 "The use of I<sighandler_t> is a GNU extension, exposed if B<_GNU_SOURCE> is "
5448 "defined; glibc also defines (the BSD-derived) I<sig_t> if B<_BSD_SOURCE> is "
5449 "defined. Without use of such a type, the declaration of B<signal>() is the "
5450 "somewhat harder to read:"
5454 #: build/C/man2/signal.2:166
5457 "B<void ( *>I<signal>B<(int >I<signum>B<, void (*>I<handler>B<)(int)) ) "
5462 #: build/C/man2/signal.2:168
5468 #: build/C/man2/signal.2:180
5470 "The only portable use of B<signal>() is to set a signal's disposition to "
5471 "B<SIG_DFL> or B<SIG_IGN>. The semantics when using B<signal>() to "
5472 "establish a signal handler vary across systems (and POSIX.1 explicitly "
5473 "permits this variation); B<do not use it for this purpose.>"
5477 #: build/C/man2/signal.2:186
5479 "POSIX.1 solved the portability mess by specifying B<sigaction>(2), which "
5480 "provides explicit control of the semantics when a signal handler is invoked; "
5481 "use that interface instead of B<signal>()."
5485 #: build/C/man2/signal.2:196
5487 "In the original UNIX systems, when a handler that was established using "
5488 "B<signal>() was invoked by the delivery of a signal, the disposition of the "
5489 "signal would be reset to B<SIG_DFL>, and the system did not block delivery "
5490 "of further instances of the signal. This is equivalent to calling "
5491 "B<sigaction>(2) with the following flags:"
5495 #: build/C/man2/signal.2:198
5497 msgid " sa.sa_flags = SA_RESETHAND | SA_NODEFER;\n"
5501 #: build/C/man2/signal.2:205
5503 "System\\ V also provides these semantics for B<signal>(). This was bad "
5504 "because the signal might be delivered again before the handler had a chance "
5505 "to reestablish itself. Furthermore, rapid deliveries of the same signal "
5506 "could result in recursive invocations of the handler."
5510 #: build/C/man2/signal.2:220
5512 "BSD improved on this situation, but unfortunately also changed the semantics "
5513 "of the existing B<signal>() interface while doing so. On BSD, when a "
5514 "signal handler is invoked, the signal disposition is not reset, and further "
5515 "instances of the signal are blocked from being delivered while the handler "
5516 "is executing. Furthermore, certain blocking system calls are automatically "
5517 "restarted if interrupted by a signal handler (see B<signal>(7)). The BSD "
5518 "semantics are equivalent to calling B<sigaction>(2) with the following "
5523 #: build/C/man2/signal.2:222
5525 msgid " sa.sa_flags = SA_RESTART;\n"
5529 #: build/C/man2/signal.2:224
5530 msgid "The situation on Linux is as follows:"
5534 #: build/C/man2/signal.2:228
5535 msgid "The kernel's B<signal>() system call provides System\\ V semantics."
5539 #: build/C/man2/signal.2:244
5541 "By default, in glibc 2 and later, the B<signal>() wrapper function does not "
5542 "invoke the kernel system call. Instead, it calls B<sigaction>(2) using "
5543 "flags that supply BSD semantics. This default behavior is provided as long "
5544 "as the B<_BSD_SOURCE> feature test macro is defined. By default, "
5545 "B<_BSD_SOURCE> is defined; it is also implicitly defined if one defines "
5546 "B<_GNU_SOURCE>, and can of course be explicitly defined."
5550 #. System V semantics are also provided if one uses the separate
5551 #. .BR sysv_signal (3)
5556 #. function in Linux libc4 and libc5 provide System\ V semantics.
5557 #. If one on a libc5 system includes
5558 #. .I <bsd/signal.h>
5563 #. provides BSD semantics.
5565 #: build/C/man2/signal.2:278
5567 "On glibc 2 and later, if the B<_BSD_SOURCE> feature test macro is not "
5568 "defined, then B<signal>() provides System\\ V semantics. (The default "
5569 "implicit definition of B<_BSD_SOURCE> is not provided if one invokes "
5570 "B<gcc>(1) in one of its standard modes (I<-std=xxx> or I<-ansi>) or "
5571 "defines various other feature test macros such as B<_POSIX_SOURCE>, "
5572 "B<_XOPEN_SOURCE>, or B<_SVID_SOURCE>; see B<feature_test_macros>(7).)"
5576 #: build/C/man2/signal.2:297
5578 "B<kill>(1), B<alarm>(2), B<kill>(2), B<killpg>(2), B<pause>(2), "
5579 "B<sigaction>(2), B<signalfd>(2), B<sigpending>(2), B<sigprocmask>(2), "
5580 "B<sigsuspend>(2), B<bsd_signal>(3), B<raise>(3), B<siginterrupt>(3), "
5581 "B<sigqueue>(3), B<sigsetops>(3), B<sigvec>(3), B<sysv_signal>(3), "
5586 #: build/C/man7/signal.7:49
5587 msgid "signal - overview of signals"
5591 #: build/C/man7/signal.7:52
5593 "Linux supports both POSIX reliable signals (hereinafter \"standard "
5594 "signals\") and POSIX real-time signals."
5598 #: build/C/man7/signal.7:52
5600 msgid "Signal dispositions"
5604 #: build/C/man7/signal.7:57
5606 "Each signal has a current I<disposition>, which determines how the process "
5607 "behaves when it is delivered the signal."
5611 #: build/C/man7/signal.7:60
5613 "The entries in the \"Action\" column of the tables below specify the default "
5614 "disposition for each signal, as follows:"
5618 #: build/C/man7/signal.7:60
5624 #: build/C/man7/signal.7:62
5625 msgid "Default action is to terminate the process."
5629 #: build/C/man7/signal.7:62
5635 #: build/C/man7/signal.7:64
5636 msgid "Default action is to ignore the signal."
5640 #: build/C/man7/signal.7:64
5646 #: build/C/man7/signal.7:67
5647 msgid "Default action is to terminate the process and dump core (see B<core>(5))."
5651 #: build/C/man7/signal.7:67
5657 #: build/C/man7/signal.7:69
5658 msgid "Default action is to stop the process."
5662 #: build/C/man7/signal.7:69
5668 #: build/C/man7/signal.7:71
5669 msgid "Default action is to continue the process if it is currently stopped."
5673 #: build/C/man7/signal.7:93
5675 "A process can change the disposition of a signal using B<sigaction>(2) or "
5676 "B<signal>(2). (The latter is less portable when establishing a signal "
5677 "handler; see B<signal>(2) for details.) Using these system calls, a "
5678 "process can elect one of the following behaviors to occur on delivery of the "
5679 "signal: perform the default action; ignore the signal; or catch the signal "
5680 "with a I<signal handler>, a programmer-defined function that is "
5681 "automatically invoked when the signal is delivered. (By default, the signal "
5682 "handler is invoked on the normal process stack. It is possible to arrange "
5683 "that the signal handler uses an alternate stack; see B<sigaltstack>(2) for "
5684 "a discussion of how to do this and when it might be useful.)"
5688 #: build/C/man7/signal.7:97
5690 "The signal disposition is a per-process attribute: in a multithreaded "
5691 "application, the disposition of a particular signal is the same for all "
5696 #: build/C/man7/signal.7:105
5698 msgid "Sending a signal"
5702 #: build/C/man7/signal.7:108
5704 "The following system calls and library functions allow the caller to send a "
5709 #: build/C/man7/signal.7:108
5715 #: build/C/man7/signal.7:111
5716 msgid "Sends a signal to the calling thread."
5720 #: build/C/man7/signal.7:116
5722 "Sends a signal to a specified process, to all members of a specified process "
5723 "group, or to all processes on the system."
5727 #: build/C/man7/signal.7:116
5729 msgid "B<killpg>(2)"
5733 #: build/C/man7/signal.7:119
5734 msgid "Sends a signal to all of the members of a specified process group."
5738 #: build/C/man7/signal.7:119
5740 msgid "B<pthread_kill>(3)"
5744 #: build/C/man7/signal.7:123
5746 "Sends a signal to a specified POSIX thread in the same process as the "
5751 #: build/C/man7/signal.7:123
5753 msgid "B<tgkill>(2)"
5757 #: build/C/man7/signal.7:128
5759 "Sends a signal to a specified thread within a specific process. (This is "
5760 "the system call used to implement B<pthread_kill>(3).)"
5764 #: build/C/man7/signal.7:131
5765 msgid "Sends a real-time signal with accompanying data to a specified process."
5769 #: build/C/man7/signal.7:131
5771 msgid "Waiting for a signal to be caught"
5775 #: build/C/man7/signal.7:135
5777 "The following system calls suspend execution of the calling process or "
5778 "thread until a signal is caught (or an unhandled signal terminates the "
5783 #: build/C/man7/signal.7:135
5789 #: build/C/man7/signal.7:138
5790 msgid "Suspends execution until any signal is caught."
5794 #: build/C/man7/signal.7:138
5796 msgid "B<sigsuspend>(2)"
5800 #: build/C/man7/signal.7:142
5802 "Temporarily changes the signal mask (see below) and suspends execution until "
5803 "one of the unmasked signals is caught."
5807 #: build/C/man7/signal.7:142
5809 msgid "Synchronously accepting a signal"
5813 #: build/C/man7/signal.7:149
5815 "Rather than asynchronously catching a signal via a signal handler, it is "
5816 "possible to synchronously accept the signal, that is, to block execution "
5817 "until the signal is delivered, at which point the kernel returns information "
5818 "about the signal to the caller. There are two general ways to do this:"
5822 #: build/C/man7/signal.7:157
5824 "B<sigwaitinfo>(2), B<sigtimedwait>(2), and B<sigwait>(3) suspend execution "
5825 "until one of the signals in a specified set is delivered. Each of these "
5826 "calls returns information about the delivered signal."
5830 #: build/C/man7/signal.7:170
5832 "B<signalfd>(2) returns a file descriptor that can be used to read "
5833 "information about signals that are delivered to the caller. Each B<read>(2) "
5834 "from this file descriptor blocks until one of the signals in the set "
5835 "specified in the B<signalfd>(2) call is delivered to the caller. The "
5836 "buffer returned by B<read>(2) contains a structure describing the signal."
5840 #: build/C/man7/signal.7:170
5842 msgid "Signal mask and pending signals"
5846 #: build/C/man7/signal.7:177
5848 "A signal may be I<blocked>, which means that it will not be delivered until "
5849 "it is later unblocked. Between the time when it is generated and when it is "
5850 "delivered a signal is said to be I<pending>."
5854 #: build/C/man7/signal.7:186
5856 "Each thread in a process has an independent I<signal mask>, which indicates "
5857 "the set of signals that the thread is currently blocking. A thread can "
5858 "manipulate its signal mask using B<pthread_sigmask>(3). In a traditional "
5859 "single-threaded application, B<sigprocmask>(2) can be used to manipulate "
5864 #: build/C/man7/signal.7:192 build/C/man2/sigprocmask.2:126
5866 "A child created via B<fork>(2) inherits a copy of its parent's signal mask; "
5867 "the signal mask is preserved across B<execve>(2)."
5871 #: build/C/man7/signal.7:209
5873 "A signal may be generated (and thus pending) for a process as a whole "
5874 "(e.g., when sent using B<kill>(2)) or for a specific thread (e.g., certain "
5875 "signals, such as B<SIGSEGV> and B<SIGFPE>, generated as a consequence of "
5876 "executing a specific machine-language instruction are thread directed, as "
5877 "are signals targeted at a specific thread using B<pthread_kill>(3)). A "
5878 "process-directed signal may be delivered to any one of the threads that does "
5879 "not currently have the signal blocked. If more than one of the threads has "
5880 "the signal unblocked, then the kernel chooses an arbitrary thread to which "
5881 "to deliver the signal."
5885 #: build/C/man7/signal.7:216
5887 "A thread can obtain the set of signals that it currently has pending using "
5888 "B<sigpending>(2). This set will consist of the union of the set of pending "
5889 "process-directed signals and the set of signals pending for the calling "
5894 #: build/C/man7/signal.7:222 build/C/man2/sigpending.2:85
5896 "A child created via B<fork>(2) initially has an empty pending signal set; "
5897 "the pending signal set is preserved across an B<execve>(2)."
5901 #: build/C/man7/signal.7:222
5903 msgid "Standard signals"
5907 #: build/C/man7/signal.7:234
5909 "Linux supports the standard signals listed below. Several signal numbers "
5910 "are architecture-dependent, as indicated in the \"Value\" column. (Where "
5911 "three values are given, the first one is usually valid for alpha and sparc, "
5912 "the middle one for x86, arm, and most other architectures, and the last one "
5913 "for mips. (Values for parisc are I<not> shown; see the Linux kernel source "
5914 "for signal numbering on that architecture.) A - denotes that a signal is "
5915 "absent on the corresponding architecture.)"
5919 #: build/C/man7/signal.7:236
5920 msgid "First the signals described in the original POSIX.1-1990 standard."
5924 #: build/C/man7/signal.7:240 build/C/man7/signal.7:276 build/C/man7/signal.7:305
5926 msgid "Signal\tValue\tAction\tComment\n"
5930 #: build/C/man7/signal.7:241
5932 msgid "SIGHUP\t\\01\tTerm\tHangup detected on controlling terminal\n"
5936 #: build/C/man7/signal.7:242
5938 msgid "\t\t\tor death of controlling process\n"
5942 #: build/C/man7/signal.7:243
5944 msgid "SIGINT\t\\02\tTerm\tInterrupt from keyboard\n"
5948 #: build/C/man7/signal.7:244
5950 msgid "SIGQUIT\t\\03\tCore\tQuit from keyboard\n"
5954 #: build/C/man7/signal.7:245
5956 msgid "SIGILL\t\\04\tCore\tIllegal Instruction\n"
5960 #: build/C/man7/signal.7:246
5962 msgid "SIGABRT\t\\06\tCore\tAbort signal from B<abort>(3)\n"
5966 #: build/C/man7/signal.7:247
5968 msgid "SIGFPE\t\\08\tCore\tFloating point exception\n"
5972 #: build/C/man7/signal.7:248
5974 msgid "SIGKILL\t\\09\tTerm\tKill signal\n"
5978 #: build/C/man7/signal.7:249
5980 msgid "SIGSEGV\t11\tCore\tInvalid memory reference\n"
5984 #: build/C/man7/signal.7:250
5986 msgid "SIGPIPE\t13\tTerm\tBroken pipe: write to pipe with no\n"
5990 #: build/C/man7/signal.7:251
5992 msgid "\t\t\treaders\n"
5996 #: build/C/man7/signal.7:252
5998 msgid "SIGALRM\t14\tTerm\tTimer signal from B<alarm>(2)\n"
6002 #: build/C/man7/signal.7:253
6004 msgid "SIGTERM\t15\tTerm\tTermination signal\n"
6008 #: build/C/man7/signal.7:254
6010 msgid "SIGUSR1\t30,10,16\tTerm\tUser-defined signal 1\n"
6014 #: build/C/man7/signal.7:255
6016 msgid "SIGUSR2\t31,12,17\tTerm\tUser-defined signal 2\n"
6020 #: build/C/man7/signal.7:256
6022 msgid "SIGCHLD\t20,17,18\tIgn\tChild stopped or terminated\n"
6026 #: build/C/man7/signal.7:257
6028 msgid "SIGCONT\t19,18,25\tCont\tContinue if stopped\n"
6032 #: build/C/man7/signal.7:258
6034 msgid "SIGSTOP\t17,19,23\tStop\tStop process\n"
6038 #: build/C/man7/signal.7:259
6040 msgid "SIGTSTP\t18,20,24\tStop\tStop typed at terminal\n"
6044 #: build/C/man7/signal.7:260
6046 msgid "SIGTTIN\t21,21,26\tStop\tTerminal input for background process\n"
6050 #: build/C/man7/signal.7:261
6052 msgid "SIGTTOU\t22,22,27\tStop\tTerminal output for background process\n"
6056 #: build/C/man7/signal.7:269
6057 msgid "The signals B<SIGKILL> and B<SIGSTOP> cannot be caught, blocked, or ignored."
6061 #: build/C/man7/signal.7:272
6063 "Next the signals not in the POSIX.1-1990 standard but described in SUSv2 and "
6068 #: build/C/man7/signal.7:277
6070 msgid "SIGBUS\t10,7,10\tCore\tBus error (bad memory access)\n"
6074 #: build/C/man7/signal.7:278
6076 msgid "SIGPOLL\t\tTerm\tPollable event (Sys V).\n"
6080 #: build/C/man7/signal.7:279
6082 msgid "\t\t\tSynonym for B<SIGIO>\n"
6086 #: build/C/man7/signal.7:280
6088 msgid "SIGPROF\t27,27,29\tTerm\tProfiling timer expired\n"
6092 #: build/C/man7/signal.7:281
6094 msgid "SIGSYS\t12,31,12\tCore\tBad argument to routine (SVr4)\n"
6098 #: build/C/man7/signal.7:282
6100 msgid "SIGTRAP\t5\tCore\tTrace/breakpoint trap\n"
6104 #: build/C/man7/signal.7:283
6106 msgid "SIGURG\t16,23,21\tIgn\tUrgent condition on socket (4.2BSD)\n"
6110 #: build/C/man7/signal.7:284
6112 msgid "SIGVTALRM\t26,26,28\tTerm\tVirtual alarm clock (4.2BSD)\n"
6116 #: build/C/man7/signal.7:285
6118 msgid "SIGXCPU\t24,24,30\tCore\tCPU time limit exceeded (4.2BSD)\n"
6122 #: build/C/man7/signal.7:286
6124 msgid "SIGXFSZ\t25,25,31\tCore\tFile size limit exceeded (4.2BSD)\n"
6128 #: build/C/man7/signal.7:299
6130 "Up to and including Linux 2.2, the default behavior for B<SIGSYS>, "
6131 "B<SIGXCPU>, B<SIGXFSZ>, and (on architectures other than SPARC and MIPS) "
6132 "B<SIGBUS> was to terminate the process (without a core dump). (On some "
6133 "other UNIX systems the default action for B<SIGXCPU> and B<SIGXFSZ> is to "
6134 "terminate the process without a core dump.) Linux 2.4 conforms to the "
6135 "POSIX.1-2001 requirements for these signals, terminating the process with a "
6140 #: build/C/man7/signal.7:301
6141 msgid "Next various other signals."
6145 #: build/C/man7/signal.7:306
6147 msgid "SIGIOT\t6\tCore\tIOT trap. A synonym for B<SIGABRT>\n"
6151 #: build/C/man7/signal.7:307
6153 msgid "SIGEMT\t7,-,7\tTerm\n"
6157 #: build/C/man7/signal.7:308
6159 msgid "SIGSTKFLT\t-,16,-\tTerm\tStack fault on coprocessor (unused)\n"
6163 #: build/C/man7/signal.7:309
6165 msgid "SIGIO\t23,29,22\tTerm\tI/O now possible (4.2BSD)\n"
6169 #: build/C/man7/signal.7:310
6171 msgid "SIGCLD\t-,-,18\tIgn\tA synonym for B<SIGCHLD>\n"
6175 #: build/C/man7/signal.7:311
6177 msgid "SIGPWR\t29,30,19\tTerm\tPower failure (System V)\n"
6181 #: build/C/man7/signal.7:312
6183 msgid "SIGINFO\t29,-,-\t\tA synonym for B<SIGPWR>\n"
6187 #: build/C/man7/signal.7:313
6189 msgid "SIGLOST\t-,-,-\tTerm\tFile lock lost (unused)\n"
6193 #: build/C/man7/signal.7:314
6195 msgid "SIGWINCH\t28,28,20\tIgn\tWindow resize signal (4.3BSD, Sun)\n"
6199 #: build/C/man7/signal.7:315
6201 msgid "SIGUNUSED\t-,31,-\tCore\tSynonymous with B<SIGSYS>\n"
6205 #: build/C/man7/signal.7:325
6206 msgid "(Signal 29 is B<SIGINFO> / B<SIGPWR> on an alpha but B<SIGLOST> on a sparc.)"
6210 #: build/C/man7/signal.7:331
6212 "B<SIGEMT> is not specified in POSIX.1-2001, but nevertheless appears on most "
6213 "other UNIX systems, where its default action is typically to terminate the "
6214 "process with a core dump."
6218 #: build/C/man7/signal.7:335
6220 "B<SIGPWR> (which is not specified in POSIX.1-2001) is typically ignored by "
6221 "default on those other UNIX systems where it appears."
6225 #: build/C/man7/signal.7:339
6227 "B<SIGIO> (which is not specified in POSIX.1-2001) is ignored by default on "
6228 "several other UNIX systems."
6231 #. parisc is the only exception: SIGSYS is 12, SIGUNUSED is 31
6233 #: build/C/man7/signal.7:346
6235 "Where defined, B<SIGUNUSED> is synonymous with B<SIGSYS> on most "
6240 #: build/C/man7/signal.7:346
6242 msgid "Real-time signals"
6246 #: build/C/man7/signal.7:356
6248 "Linux supports real-time signals as originally defined in the POSIX.1b "
6249 "real-time extensions (and now included in POSIX.1-2001). The range of "
6250 "supported real-time signals is defined by the macros B<SIGRTMIN> and "
6251 "B<SIGRTMAX>. POSIX.1-2001 requires that an implementation support at least "
6252 "B<_POSIX_RTSIG_MAX> (8) real-time signals."
6256 #: build/C/man7/signal.7:378
6258 "The Linux kernel supports a range of 32 different real-time signals, "
6259 "numbered 33 to 64. However, the glibc POSIX threads implementation "
6260 "internally uses two (for NPTL) or three (for LinuxThreads) real-time signals "
6261 "(see B<pthreads>(7)), and adjusts the value of B<SIGRTMIN> suitably (to 34 "
6262 "or 35). Because the range of available real-time signals varies according "
6263 "to the glibc threading implementation (and this variation can occur at run "
6264 "time according to the available kernel and glibc), and indeed the range of "
6265 "real-time signals varies across UNIX systems, programs should I<never refer "
6266 "to real-time signals using hard-coded numbers>, but instead should always "
6267 "refer to real-time signals using the notation B<SIGRTMIN>+n, and include "
6268 "suitable (run-time) checks that B<SIGRTMIN>+n does not exceed B<SIGRTMAX>."
6272 #: build/C/man7/signal.7:382
6274 "Unlike standard signals, real-time signals have no predefined meanings: the "
6275 "entire set of real-time signals can be used for application-defined "
6280 #: build/C/man7/signal.7:385
6282 "The default action for an unhandled real-time signal is to terminate the "
6283 "receiving process."
6287 #: build/C/man7/signal.7:387
6288 msgid "Real-time signals are distinguished by the following:"
6292 #: build/C/man7/signal.7:391
6294 "Multiple instances of real-time signals can be queued. By contrast, if "
6295 "multiple instances of a standard signal are delivered while that signal is "
6296 "currently blocked, then only one instance is queued."
6300 #: build/C/man7/signal.7:411
6302 "If the signal is sent using B<sigqueue>(3), an accompanying value (either an "
6303 "integer or a pointer) can be sent with the signal. If the receiving process "
6304 "establishes a handler for this signal using the B<SA_SIGINFO> flag to "
6305 "B<sigaction>(2), then it can obtain this data via the I<si_value> field of "
6306 "the I<siginfo_t> structure passed as the second argument to the handler. "
6307 "Furthermore, the I<si_pid> and I<si_uid> fields of this structure can be "
6308 "used to obtain the PID and real user ID of the process sending the signal."
6312 #: build/C/man7/signal.7:420
6314 "Real-time signals are delivered in a guaranteed order. Multiple real-time "
6315 "signals of the same type are delivered in the order they were sent. If "
6316 "different real-time signals are sent to a process, they are delivered "
6317 "starting with the lowest-numbered signal. (I.e., low-numbered signals have "
6318 "highest priority.) By contrast, if multiple standard signals are pending "
6319 "for a process, the order in which they are delivered is unspecified."
6323 #: build/C/man7/signal.7:425
6325 "If both standard and real-time signals are pending for a process, POSIX "
6326 "leaves it unspecified which is delivered first. Linux, like many other "
6327 "implementations, gives priority to standard signals in this case."
6331 #: build/C/man7/signal.7:448
6333 "According to POSIX, an implementation should permit at least "
6334 "B<_POSIX_SIGQUEUE_MAX> (32) real-time signals to be queued to a process. "
6335 "However, Linux does things differently. In kernels up to and including "
6336 "2.6.7, Linux imposes a system-wide limit on the number of queued real-time "
6337 "signals for all processes. This limit can be viewed and (with privilege) "
6338 "changed via the I</proc/sys/kernel/rtsig-max> file. A related file, "
6339 "I</proc/sys/kernel/rtsig-nr>, can be used to find out how many real-time "
6340 "signals are currently queued. In Linux 2.6.8, these I</proc> interfaces "
6341 "were replaced by the B<RLIMIT_SIGPENDING> resource limit, which specifies a "
6342 "per-user limit for queued signals; see B<setrlimit>(2) for further details."
6346 #: build/C/man7/signal.7:448
6348 msgid "Async-signal-safe functions"
6352 #: build/C/man7/signal.7:457
6354 "A signal handler function must be very careful, since processing elsewhere "
6355 "may be interrupted at some arbitrary point in the execution of the program. "
6356 "POSIX has the concept of \"safe function\". If a signal interrupts the "
6357 "execution of an unsafe function, and I<handler> calls an unsafe function, "
6358 "then the behavior of the program is undefined."
6362 #: build/C/man7/signal.7:461
6364 "POSIX.1-2004 (also known as POSIX.1-2001 Technical Corrigendum 2) requires "
6365 "an implementation to guarantee that the following functions can be safely "
6366 "called inside a signal handler:"
6370 #: build/C/man7/signal.7:582
6430 "posix_trace_event()\n"
6480 "timer_getoverrun()\n"
6494 #: build/C/man7/signal.7:587
6496 "POSIX.1-2008 removes fpathconf(), pathconf(), and sysconf() from the above "
6497 "list, and adds the following functions:"
6501 #: build/C/man7/signal.7:610
6527 #: build/C/man7/signal.7:612
6529 msgid "Interruption of system calls and library functions by signal handlers"
6533 #: build/C/man7/signal.7:615
6535 "If a signal handler is invoked while a system call or library function call "
6536 "is blocked, then either:"
6540 #: build/C/man7/signal.7:617
6541 msgid "the call is automatically restarted after the signal handler returns; or"
6545 #: build/C/man7/signal.7:620
6546 msgid "the call fails with the error B<EINTR>."
6550 #: build/C/man7/signal.7:628
6552 "Which of these two behaviors occurs depends on the interface and whether or "
6553 "not the signal handler was established using the B<SA_RESTART> flag (see "
6554 "B<sigaction>(2)). The details vary across UNIX systems; below, the details "
6558 #. The following system calls use ERESTARTSYS,
6559 #. so that they are restartable
6561 #: build/C/man7/signal.7:637
6563 "If a blocked call to one of the following interfaces is interrupted by a "
6564 "signal handler, then the call will be automatically restarted after the "
6565 "signal handler returns if the B<SA_RESTART> flag was used; otherwise the "
6566 "call will fail with the error B<EINTR>:"
6569 #. commit 1ca39ab9d21ac93f94b9e3eb364ea9a5cf2aba06
6571 #: build/C/man7/signal.7:672
6573 "B<read>(2), B<readv>(2), B<write>(2), B<writev>(2), and B<ioctl>(2) calls "
6574 "on \"slow\" devices. A \"slow\" device is one where the I/O call may block "
6575 "for an indefinite time, for example, a terminal, pipe, or socket. (A disk "
6576 "is not a slow device according to this definition.) A B<read>(2) on an "
6577 "B<eventfd>(2), B<signalfd>(2), B<timerfd>(2), B<fanotify>(7), or "
6578 "B<inotify>(7) file descriptor is also considered to be a \"slow\" "
6579 "operation. (Before Linux 3.8, reads from an B<inotify>(7) file descriptor "
6580 "were not restartable; when interrupted by a signal handler, B<read>(2) "
6581 "always failed with the error B<EINTR>.) If an I/O call on a slow device has "
6582 "already transferred some data by the time it is interrupted by a signal "
6583 "handler, then the call will return a success status (normally, the number of "
6584 "bytes transferred)."
6588 #: build/C/man7/signal.7:676
6589 msgid "B<open>(2), if it can block (e.g., when opening a FIFO; see B<fifo>(7))."
6593 #: build/C/man7/signal.7:683
6594 msgid "B<wait>(2), B<wait3>(2), B<wait4>(2), B<waitid>(2), and B<waitpid>(2)."
6597 #. If a timeout (setsockopt()) is in effect on the socket, then these
6598 #. system calls switch to using EINTR. Consequently, they and are not
6599 #. automatically restarted, and they show the stop/cont behavior
6600 #. described below. (Verified from 2.6.26 source, and by experiment; mtk)
6601 #. FIXME . What about sendmmsg()?
6603 #: build/C/man7/signal.7:701
6605 "Socket interfaces: B<accept>(2), B<connect>(2), B<recv>(2), B<recvfrom>(2), "
6606 "B<recvmmsg>(2), B<recvmsg>(2), B<send>(2), B<sendto>(2), and B<sendmsg>(2), "
6607 "unless a timeout has been set on the socket (see below)."
6611 #: build/C/man7/signal.7:707
6612 msgid "File locking interfaces: B<flock>(2) and B<fcntl>(2) B<F_SETLKW>."
6616 #: build/C/man7/signal.7:714
6618 "POSIX message queue interfaces: B<mq_receive>(3), B<mq_timedreceive>(3), "
6619 "B<mq_send>(3), and B<mq_timedsend>(3)."
6623 #: build/C/man7/signal.7:719
6625 "B<futex>(2) B<FUTEX_WAIT> (since Linux 2.6.22; beforehand, always failed "
6630 #: build/C/man7/signal.7:723
6631 msgid "B<pthread_mutex_lock>(3), B<pthread_cond_wait>(3), and related APIs."
6635 #: build/C/man7/signal.7:730
6637 "POSIX semaphore interfaces: B<sem_wait>(3) and B<sem_timedwait>(3) (since "
6638 "Linux 2.6.22; beforehand, always failed with B<EINTR>)."
6641 #. These are the system calls that give EINTR or ERESTARTNOHAND
6642 #. on interruption by a signal handler.
6644 #: build/C/man7/signal.7:741
6646 "The following interfaces are never restarted after being interrupted by a "
6647 "signal handler, regardless of the use of B<SA_RESTART>; they always fail "
6648 "with the error B<EINTR> when interrupted by a signal handler:"
6652 #: build/C/man7/signal.7:756 build/C/man7/signal.7:831
6654 "\"Input\" socket interfaces, when a timeout (B<SO_RCVTIMEO>) has been set "
6655 "on the socket using B<setsockopt>(2): B<accept>(2), B<recv>(2), "
6656 "B<recvfrom>(2), B<recvmmsg>(2) (also with a non-NULL I<timeout> argument), "
6657 "and B<recvmsg>(2)."
6660 #. FIXME . What about sendmmsg()?
6662 #: build/C/man7/signal.7:767 build/C/man7/signal.7:842
6664 "\"Output\" socket interfaces, when a timeout (B<SO_SNDTIMEO>) has been set "
6665 "on the socket using B<setsockopt>(2): B<connect>(2), B<send>(2), "
6666 "B<sendto>(2), and B<sendmsg>(2)."
6670 #: build/C/man7/signal.7:774
6672 "Interfaces used to wait for signals: B<pause>(2), B<sigsuspend>(2), "
6673 "B<sigtimedwait>(2), and B<sigwaitinfo>(2)."
6677 #: build/C/man7/signal.7:783
6679 "File descriptor multiplexing interfaces: B<epoll_wait>(2), "
6680 "B<epoll_pwait>(2), B<poll>(2), B<ppoll>(2), B<select>(2), and B<pselect>(2)."
6683 #. On some other systems, SA_RESTART does restart these system calls
6685 #: build/C/man7/signal.7:791
6687 "System V IPC interfaces: B<msgrcv>(2), B<msgsnd>(2), B<semop>(2), and "
6692 #: build/C/man7/signal.7:797
6693 msgid "Sleep interfaces: B<clock_nanosleep>(2), B<nanosleep>(2), and B<usleep>(3)."
6697 #: build/C/man7/signal.7:799
6698 msgid "B<io_getevents>(2)."
6702 #: build/C/man7/signal.7:805
6704 "The B<sleep>(3) function is also never restarted if interrupted by a "
6705 "handler, but gives a success return: the number of seconds remaining to "
6710 #: build/C/man7/signal.7:805
6712 msgid "Interruption of system calls and library functions by stop signals"
6716 #: build/C/man7/signal.7:814
6718 "On Linux, even in the absence of signal handlers, certain blocking "
6719 "interfaces can fail with the error B<EINTR> after the process is stopped by "
6720 "one of the stop signals and then resumed via B<SIGCONT>. This behavior is "
6721 "not sanctioned by POSIX.1, and doesn't occur on other systems."
6725 #: build/C/man7/signal.7:816
6726 msgid "The Linux interfaces that display this behavior are:"
6730 #: build/C/man7/signal.7:845
6731 msgid "B<epoll_wait>(2), B<epoll_pwait>(2)."
6735 #: build/C/man7/signal.7:848
6736 msgid "B<semop>(2), B<semtimedop>(2)."
6740 #: build/C/man7/signal.7:851
6741 msgid "B<sigtimedwait>(2), B<sigwaitinfo>(2)."
6744 #. commit 1ca39ab9d21ac93f94b9e3eb364ea9a5cf2aba06
6746 #: build/C/man7/signal.7:858
6747 msgid "Linux 3.7 and earlier: B<read>(2) from an B<inotify>(7) file descriptor."
6751 #: build/C/man7/signal.7:864
6753 "Linux 2.6.21 and earlier: B<futex>(2) B<FUTEX_WAIT>, B<sem_timedwait>(3), "
6758 #: build/C/man7/signal.7:868
6759 msgid "Linux 2.6.8 and earlier: B<msgrcv>(2), B<msgsnd>(2)."
6763 #: build/C/man7/signal.7:871
6764 msgid "Linux 2.4 and earlier: B<nanosleep>(2)."
6767 #. It must be a *very* long time since this was true:
6772 #. have the same value.
6773 #. The latter is commented out in the kernel source, but
6774 #. the build process of some software still thinks that
6778 #: build/C/man7/signal.7:884
6779 msgid "POSIX.1, except as noted."
6783 #: build/C/man7/signal.7:919
6785 "B<kill>(1), B<getrlimit>(2), B<kill>(2), B<killpg>(2), "
6786 "B<restart_syscall>(2), B<rt_sigqueueinfo>(2), B<setitimer>(2), "
6787 "B<setrlimit>(2), B<sgetmask>(2), B<sigaction>(2), B<sigaltstack>(2), "
6788 "B<signal>(2), B<signalfd>(2), B<sigpending>(2), B<sigprocmask>(2), "
6789 "B<sigreturn>(2), B<sigsuspend>(2), B<sigwaitinfo>(2), B<abort>(3), "
6790 "B<bsd_signal>(3), B<longjmp>(3), B<raise>(3), B<pthread_sigqueue>(3), "
6791 "B<sigqueue>(3), B<sigset>(3), B<sigsetops>(3), B<sigvec>(3), B<sigwait>(3), "
6792 "B<strsignal>(3), B<sysv_signal>(3), B<core>(5), B<proc>(5), B<pthreads>(7), "
6797 #: build/C/man2/signalfd.2:20
6803 #: build/C/man2/signalfd.2:23
6804 msgid "signalfd - create a file descriptor for accepting signals"
6808 #: build/C/man2/signalfd.2:25
6809 msgid "B<#include E<lt>sys/signalfd.hE<gt>>"
6813 #: build/C/man2/signalfd.2:27
6814 msgid "B<int signalfd(int >I<fd>B<, const sigset_t *>I<mask>B<, int >I<flags>B<);>"
6818 #: build/C/man2/signalfd.2:38
6820 "B<signalfd>() creates a file descriptor that can be used to accept signals "
6821 "targeted at the caller. This provides an alternative to the use of a signal "
6822 "handler or B<sigwaitinfo>(2), and has the advantage that the file descriptor "
6823 "may be monitored by B<select>(2), B<poll>(2), and B<epoll>(7)."
6827 #: build/C/man2/signalfd.2:58
6829 "The I<mask> argument specifies the set of signals that the caller wishes to "
6830 "accept via the file descriptor. This argument is a signal set whose "
6831 "contents can be initialized using the macros described in B<sigsetops>(3). "
6832 "Normally, the set of signals to be received via the file descriptor should "
6833 "be blocked using B<sigprocmask>(2), to prevent the signals being handled "
6834 "according to their default dispositions. It is not possible to receive "
6835 "B<SIGKILL> or B<SIGSTOP> signals via a signalfd file descriptor; these "
6836 "signals are silently ignored if specified in I<mask>."
6840 #: build/C/man2/signalfd.2:72
6842 "If the I<fd> argument is -1, then the call creates a new file descriptor and "
6843 "associates the signal set specified in I<mask> with that descriptor. If "
6844 "I<fd> is not -1, then it must specify a valid existing signalfd file "
6845 "descriptor, and I<mask> is used to replace the signal set associated with "
6850 #: build/C/man2/signalfd.2:77
6852 "Starting with Linux 2.6.27, the following values may be bitwise ORed in "
6853 "I<flags> to change the behavior of B<signalfd>():"
6857 #: build/C/man2/signalfd.2:77
6859 msgid "B<SFD_NONBLOCK>"
6863 #: build/C/man2/signalfd.2:85
6865 msgid "B<SFD_CLOEXEC>"
6869 #: build/C/man2/signalfd.2:102
6871 "B<signalfd>() returns a file descriptor that supports the following "
6876 #: build/C/man2/signalfd.2:121
6878 "If one or more of the signals specified in I<mask> is pending for the "
6879 "process, then the buffer supplied to B<read>(2) is used to return one or "
6880 "more I<signalfd_siginfo> structures (see below) that describe the signals. "
6881 "The B<read>(2) returns information for as many signals as are pending and "
6882 "will fit in the supplied buffer. The buffer must be at least "
6883 "I<sizeof(struct signalfd_siginfo)> bytes. The return value of the "
6884 "B<read>(2) is the total number of bytes read."
6888 #: build/C/man2/signalfd.2:129
6890 "As a consequence of the B<read>(2), the signals are consumed, so that they "
6891 "are no longer pending for the process (i.e., will not be caught by signal "
6892 "handlers, and cannot be accepted using B<sigwaitinfo>(2))."
6896 #: build/C/man2/signalfd.2:140
6898 "If none of the signals in I<mask> is pending for the process, then the "
6899 "B<read>(2) either blocks until one of the signals in I<mask> is generated "
6900 "for the process, or fails with the error B<EAGAIN> if the file descriptor "
6901 "has been made nonblocking."
6905 #: build/C/man2/signalfd.2:153
6907 "The file descriptor is readable (the B<select>(2) I<readfds> argument; the "
6908 "B<poll>(2) B<POLLIN> flag) if one or more of the signals in I<mask> is "
6909 "pending for the process."
6913 #: build/C/man2/signalfd.2:160
6915 "The signalfd file descriptor also supports the other file-descriptor "
6916 "multiplexing APIs: B<pselect>(2), B<ppoll>(2), and B<epoll>(7)."
6920 #: build/C/man2/signalfd.2:165
6922 "When the file descriptor is no longer required it should be closed. When "
6923 "all file descriptors associated with the same signalfd object have been "
6924 "closed, the resources for object are freed by the kernel."
6928 #: build/C/man2/signalfd.2:165
6930 msgid "The signalfd_siginfo structure"
6934 #: build/C/man2/signalfd.2:171
6936 "The format of the I<signalfd_siginfo> structure(s) returned by B<read>(2)s "
6937 "from a signalfd file descriptor is as follows:"
6940 #. ssi_trapno is unused on most arches
6941 #. FIXME Since Linux 2.6.37 there is 'uint16_t ssi_addr_lsb'
6942 #. in the signalfd_siginfo structure. This needs to be documented.
6944 #: build/C/man2/signalfd.2:198
6947 "struct signalfd_siginfo {\n"
6948 " uint32_t ssi_signo; /* Signal number */\n"
6949 " int32_t ssi_errno; /* Error number (unused) */\n"
6950 " int32_t ssi_code; /* Signal code */\n"
6951 " uint32_t ssi_pid; /* PID of sender */\n"
6952 " uint32_t ssi_uid; /* Real UID of sender */\n"
6953 " int32_t ssi_fd; /* File descriptor (SIGIO) */\n"
6954 " uint32_t ssi_tid; /* Kernel timer ID (POSIX timers)\n"
6955 " uint32_t ssi_band; /* Band event (SIGIO) */\n"
6956 " uint32_t ssi_overrun; /* POSIX timer overrun count */\n"
6957 " uint32_t ssi_trapno; /* Trap number that caused signal */\n"
6958 " int32_t ssi_status; /* Exit status or signal (SIGCHLD) */\n"
6959 " int32_t ssi_int; /* Integer sent by sigqueue(3) */\n"
6960 " uint64_t ssi_ptr; /* Pointer sent by sigqueue(3) */\n"
6961 " uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */\n"
6962 " uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */\n"
6963 " uint64_t ssi_addr; /* Address that generated signal\n"
6964 " (for hardware-generated signals) */\n"
6965 " uint8_t pad[I<X>]; /* Pad size to 128 bytes (allow for\n"
6966 " additional fields in the future) */\n"
6971 #: build/C/man2/signalfd.2:221
6973 "Each of the fields in this structure is analogous to the similarly named "
6974 "field in the I<siginfo_t> structure. The I<siginfo_t> structure is "
6975 "described in B<sigaction>(2). Not all fields in the returned "
6976 "I<signalfd_siginfo> structure will be valid for a specific signal; the set "
6977 "of valid fields can be determined from the value returned in the I<ssi_code> "
6978 "field. This field is the analog of the I<siginfo_t> I<si_code> field; see "
6979 "B<sigaction>(2) for details."
6983 #: build/C/man2/signalfd.2:221 build/C/man2/timerfd_create.2:276
6985 msgid "fork(2) semantics"
6989 #: build/C/man2/signalfd.2:229
6991 "After a B<fork>(2), the child inherits a copy of the signalfd file "
6992 "descriptor. A B<read>(2) from the file descriptor in the child will return "
6993 "information about signals queued to the child."
6997 #: build/C/man2/signalfd.2:229 build/C/man2/timerfd_create.2:288
6999 msgid "execve(2) semantics"
7003 #: build/C/man2/signalfd.2:241
7005 "Just like any other file descriptor, a signalfd file descriptor remains open "
7006 "across an B<execve>(2), unless it has been marked for close-on-exec (see "
7007 "B<fcntl>(2)). Any signals that were available for reading before the "
7008 "B<execve>(2) remain available to the newly loaded program. (This is "
7009 "analogous to traditional signal semantics, where a blocked signal that is "
7010 "pending remains pending across an B<execve>(2).)"
7014 #: build/C/man2/signalfd.2:241
7016 msgid "Thread semantics"
7020 #: build/C/man2/signalfd.2:251
7022 "The semantics of signalfd file descriptors in a multithreaded program mirror "
7023 "the standard semantics for signals. In other words, when a thread reads "
7024 "from a signalfd file descriptor, it will read the signals that are directed "
7025 "to the thread itself and the signals that are directed to the process (i.e., "
7026 "the entire thread group). (A thread will not be able to read signals that "
7027 "are directed to other threads in the process.)"
7031 #: build/C/man2/signalfd.2:265
7033 "On success, B<signalfd>() returns a signalfd file descriptor; this is "
7034 "either a new file descriptor (if I<fd> was -1), or I<fd> if I<fd> was a "
7035 "valid signalfd file descriptor. On error, -1 is returned and I<errno> is "
7036 "set to indicate the error."
7040 #: build/C/man2/signalfd.2:271
7041 msgid "The I<fd> file descriptor is not a valid file descriptor."
7046 #. argument is not equal to
7047 #. .IR sizeof(sigset_t) ;
7049 #: build/C/man2/signalfd.2:279
7050 msgid "I<fd> is not a valid signalfd file descriptor."
7054 #: build/C/man2/signalfd.2:286 build/C/man2/timerfd_create.2:327
7055 msgid "I<flags> is invalid; or, in Linux 2.6.26 or earlier, I<flags> is nonzero."
7059 #: build/C/man2/signalfd.2:289 build/C/man2/timerfd_create.2:330
7060 msgid "The per-process limit of open file descriptors has been reached."
7064 #: build/C/man2/signalfd.2:299
7065 msgid "There was insufficient memory to create a new signalfd file descriptor."
7068 #. signalfd() is in glibc 2.7, but reportedly does not build
7070 #: build/C/man2/signalfd.2:307
7072 "B<signalfd>() is available on Linux since kernel 2.6.22. Working support "
7073 "is provided in glibc since version 2.8. The B<signalfd4>() system call "
7074 "(see NOTES) is available on Linux since kernel 2.6.27."
7078 #: build/C/man2/signalfd.2:312
7079 msgid "B<signalfd>() and B<signalfd4>() are Linux-specific."
7083 #: build/C/man2/signalfd.2:326
7085 "A process can create multiple signalfd file descriptors. This makes it "
7086 "possible to accept different signals on different file descriptors. (This "
7087 "may be useful if monitoring the file descriptors using B<select>(2), "
7088 "B<poll>(2), or B<epoll>(7): the arrival of different signals will make "
7089 "different descriptors ready.) If a signal appears in the I<mask> of more "
7090 "than one of the file descriptors, then occurrences of that signal can be "
7091 "read (once) from any one of the descriptors."
7095 #: build/C/man2/signalfd.2:336
7097 "The underlying Linux system call requires an additional argument, I<size_t "
7098 "sizemask>, which specifies the size of the I<mask> argument. The glibc "
7099 "B<signalfd>() wrapper function does not include this argument, since it "
7100 "provides the required value for the underlying system call."
7104 #: build/C/man2/signalfd.2:352
7106 "There are two underlying Linux system calls: B<signalfd>() and the more "
7107 "recent B<signalfd4>(). The former system call does not implement a I<flags> "
7108 "argument. The latter system call implements the I<flags> values described "
7109 "above. Starting with glibc 2.9, the B<signalfd>() wrapper function will "
7110 "use B<signalfd4>() where it is available."
7113 #. The fix also was put into 2.6.24.5
7115 #: build/C/man2/signalfd.2:360
7117 "In kernels before 2.6.25, the I<ssi_ptr> and I<ssi_int> fields are not "
7118 "filled in with the data accompanying a signal sent by B<sigqueue>(3)."
7122 #: build/C/man2/signalfd.2:370
7124 "The program below accepts the signals B<SIGINT> and B<SIGQUIT> via a "
7125 "signalfd file descriptor. The program terminates after accepting a "
7126 "B<SIGQUIT> signal. The following shell session demonstrates the use of the "
7131 #: build/C/man2/signalfd.2:381
7134 "$B< ./signalfd_demo>\n"
7135 "B<^C> # Control-C generates SIGINT\n"
7139 "B<^\\e> # Control-\\e generates SIGQUIT\n"
7145 #: build/C/man2/signalfd.2:391
7148 "#include E<lt>sys/signalfd.hE<gt>\n"
7149 "#include E<lt>signal.hE<gt>\n"
7150 "#include E<lt>unistd.hE<gt>\n"
7151 "#include E<lt>stdlib.hE<gt>\n"
7152 "#include E<lt>stdio.hE<gt>\n"
7156 #: build/C/man2/signalfd.2:402
7160 "main(int argc, char *argv[])\n"
7164 " struct signalfd_siginfo fdsi;\n"
7169 #: build/C/man2/signalfd.2:406
7172 " sigemptyset(&mask);\n"
7173 " sigaddset(&mask, SIGINT);\n"
7174 " sigaddset(&mask, SIGQUIT);\n"
7178 #: build/C/man2/signalfd.2:409
7181 " /* Block signals so that they aren\\(aqt handled\n"
7182 " according to their default dispositions */\n"
7186 #: build/C/man2/signalfd.2:412
7189 " if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)\n"
7190 " handle_error(\"sigprocmask\");\n"
7194 #: build/C/man2/signalfd.2:416
7197 " sfd = signalfd(-1, &mask, 0);\n"
7199 " handle_error(\"signalfd\");\n"
7203 #: build/C/man2/signalfd.2:421
7207 " s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));\n"
7208 " if (s != sizeof(struct signalfd_siginfo))\n"
7209 " handle_error(\"read\");\n"
7213 #: build/C/man2/signalfd.2:432
7216 " if (fdsi.ssi_signo == SIGINT) {\n"
7217 " printf(\"Got SIGINT\\en\");\n"
7218 " } else if (fdsi.ssi_signo == SIGQUIT) {\n"
7219 " printf(\"Got SIGQUIT\\en\");\n"
7220 " exit(EXIT_SUCCESS);\n"
7222 " printf(\"Read unexpected signal\\en\");\n"
7229 #: build/C/man2/signalfd.2:446
7231 "B<eventfd>(2), B<poll>(2), B<read>(2), B<select>(2), B<sigaction>(2), "
7232 "B<sigprocmask>(2), B<sigwaitinfo>(2), B<timerfd_create>(2), B<sigsetops>(3), "
7233 "B<sigwait>(3), B<epoll>(7), B<signal>(7)"
7237 #: build/C/man3/sigpause.3:25
7243 #: build/C/man3/sigpause.3:28
7244 msgid "sigpause - atomically release blocked signals and wait for interrupt"
7248 #: build/C/man3/sigpause.3:33
7250 msgid "B<int sigpause(int >I<sigmask>B<); /* BSD (but see NOTES) */>\n"
7254 #: build/C/man3/sigpause.3:35
7256 msgid "B<int sigpause(int >I<sig>B<); /* System V / UNIX 95 */>\n"
7260 #: build/C/man3/sigpause.3:41
7261 msgid "Don't use this function. Use B<sigsuspend>(2) instead."
7265 #: build/C/man3/sigpause.3:48
7267 "The function B<sigpause>() is designed to wait for some signal. It changes "
7268 "the process's signal mask (set of blocked signals), and then waits for a "
7269 "signal to arrive. Upon arrival of a signal, the original signal mask is "
7274 #: build/C/man3/sigpause.3:56
7276 "If B<sigpause>() returns, it was interrupted by a signal and the return "
7277 "value is -1 with I<errno> set to B<EINTR>."
7281 #: build/C/man3/sigpause.3:61
7282 msgid "The B<sigpause>() function is thread-safe."
7286 #: build/C/man3/sigpause.3:65
7287 msgid "The System V version of B<sigpause>() is standardized in POSIX.1-2001."
7290 #. __xpg_sigpause: UNIX 95, spec 1170, SVID, SVr4, XPG
7292 #: build/C/man3/sigpause.3:82
7294 "The classical BSD version of this function appeared in 4.2BSD. It sets the "
7295 "process's signal mask to I<sigmask>. UNIX 95 standardized the incompatible "
7296 "System V version of this function, which removes only the specified signal "
7297 "I<sig> from the process's signal mask. The unfortunate situation with two "
7298 "incompatible functions with the same name was solved by the "
7299 "B<\\%sigsuspend>(2) function, that takes a I<sigset_t\\ *> argument "
7300 "(instead of an I<int>)."
7304 #: build/C/man3/sigpause.3:85
7306 "On Linux, this routine is a system call only on the Sparc (sparc64) "
7310 #. Libc4 and libc5 know only about the BSD version.
7313 #. For the BSD version, one usually uses a zero
7315 #. to indicate that no signals are to be blocked.
7317 #: build/C/man3/sigpause.3:111
7319 "Glibc uses the BSD version if the B<_BSD_SOURCE> feature test macro is "
7320 "defined and none of B<_POSIX_SOURCE>, B<_POSIX_C_SOURCE>, B<_XOPEN_SOURCE>, "
7321 "B<_GNU_SOURCE>, or B<_SVID_SOURCE> is defined. Otherwise, the System V "
7322 "version is used (and B<_XOPEN_SOURCE> must be defined to obtain the "
7323 "declaration). Since glibc 2.19, only the System V version is exposed by "
7324 "I<E<lt>signal.hE<gt>>; applications that formerly used the BSD B<sigpause>() "
7325 "should be amended to use B<sigsuspend>(2)."
7329 #: build/C/man3/sigpause.3:119
7331 "B<kill>(2), B<sigaction>(2), B<sigprocmask>(2), B<sigsuspend>(2), "
7332 "B<sigblock>(3), B<sigvec>(3), B<feature_test_macros>(7)"
7336 #: build/C/man2/sigpending.2:29
7342 #: build/C/man2/sigpending.2:29
7348 #: build/C/man2/sigpending.2:32
7349 msgid "sigpending - examine pending signals"
7353 #: build/C/man2/sigpending.2:36
7354 msgid "B<int sigpending(sigset_t *>I<set>B<);>"
7358 #: build/C/man2/sigpending.2:45
7360 "B<sigpending>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
7365 #: build/C/man2/sigpending.2:53
7367 "B<sigpending>() returns the set of signals that are pending for delivery to "
7368 "the calling thread (i.e., the signals which have been raised while "
7369 "blocked). The mask of pending signals is returned in I<set>."
7373 #: build/C/man2/sigpending.2:59
7375 "B<sigpending>() returns 0 on success and -1 on error. In the event of an "
7376 "error, I<errno> is set to indicate the cause."
7380 #: build/C/man2/sigpending.2:64
7382 "I<set> points to memory which is not a valid part of the process address "
7387 #: build/C/man2/sigpending.2:74
7389 "If a signal is both blocked and has a disposition of \"ignored\", it is "
7390 "I<not> added to the mask of pending signals when generated."
7394 #: build/C/man2/sigpending.2:79
7396 "The set of signals that is pending for a thread is the union of the set of "
7397 "signals that is pending for that thread and the set of signals that is "
7398 "pending for the process as a whole; see B<signal>(7)."
7402 #: build/C/man2/sigpending.2:91
7404 "In versions of glibc up to and including 2.2.1, there is a bug in the "
7405 "wrapper function for B<sigpending>() which means that information about "
7406 "pending real-time signals is not correctly returned."
7410 #: build/C/man2/sigpending.2:99
7412 "B<kill>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
7413 "B<sigsuspend>(2), B<sigsetops>(3), B<signal>(7)"
7417 #: build/C/man2/sigprocmask.2:29
7423 #: build/C/man2/sigprocmask.2:29 build/C/man2/sigsuspend.2:29
7429 #: build/C/man2/sigprocmask.2:32
7430 msgid "sigprocmask - examine and change blocked signals"
7434 #: build/C/man2/sigprocmask.2:37
7436 "B<int sigprocmask(int >I<how>B<, const sigset_t *>I<set>B<,> B<sigset_t "
7441 #: build/C/man2/sigprocmask.2:46
7443 "B<sigprocmask>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
7448 #: build/C/man2/sigprocmask.2:55
7450 "B<sigprocmask>() is used to fetch and/or change the signal mask of the "
7451 "calling thread. The signal mask is the set of signals whose delivery is "
7452 "currently blocked for the caller (see also B<signal>(7) for more details)."
7456 #: build/C/man2/sigprocmask.2:59
7457 msgid "The behavior of the call is dependent on the value of I<how>, as follows."
7461 #: build/C/man2/sigprocmask.2:59
7463 msgid "B<SIG_BLOCK>"
7467 #: build/C/man2/sigprocmask.2:64
7469 "The set of blocked signals is the union of the current set and the I<set> "
7474 #: build/C/man2/sigprocmask.2:64
7476 msgid "B<SIG_UNBLOCK>"
7480 #: build/C/man2/sigprocmask.2:70
7482 "The signals in I<set> are removed from the current set of blocked signals. "
7483 "It is permissible to attempt to unblock a signal which is not blocked."
7487 #: build/C/man2/sigprocmask.2:70
7489 msgid "B<SIG_SETMASK>"
7493 #: build/C/man2/sigprocmask.2:74
7494 msgid "The set of blocked signals is set to the argument I<set>."
7498 #: build/C/man2/sigprocmask.2:79
7500 "If I<oldset> is non-NULL, the previous value of the signal mask is stored in "
7505 #: build/C/man2/sigprocmask.2:88
7507 "If I<set> is NULL, then the signal mask is unchanged (i.e., I<how> is "
7508 "ignored), but the current value of the signal mask is nevertheless returned "
7509 "in I<oldset> (if it is not NULL)."
7513 #: build/C/man2/sigprocmask.2:93
7515 "The use of B<sigprocmask>() is unspecified in a multithreaded process; see "
7516 "B<pthread_sigmask>(3)."
7520 #: build/C/man2/sigprocmask.2:99
7522 "B<sigprocmask>() returns 0 on success and -1 on error. In the event of an "
7523 "error, I<errno> is set to indicate the cause."
7527 #: build/C/man2/sigprocmask.2:107
7529 "the I<set> or I<oldset> argument points outside the process's allocated "
7534 #: build/C/man2/sigprocmask.2:112
7535 msgid "The value specified in I<how> was invalid."
7539 #: build/C/man2/sigprocmask.2:118
7541 "It is not possible to block B<SIGKILL> or B<SIGSTOP>. Attempts to do so are "
7546 #: build/C/man2/sigprocmask.2:120
7547 msgid "Each of the threads in a process has its own signal mask."
7551 #: build/C/man2/sigprocmask.2:140
7553 "If B<SIGBUS>, B<SIGFPE>, B<SIGILL>, or B<SIGSEGV> are generated while they "
7554 "are blocked, the result is undefined, unless the signal was generated by "
7555 "B<kill>(2), B<sigqueue>(3), or B<raise>(3)."
7559 #: build/C/man2/sigprocmask.2:155
7561 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigpending>(2), "
7562 "B<sigsuspend>(2), B<pthread_sigmask>(3), B<sigqueue>(3), B<sigsetops>(3), "
7567 #: build/C/man3/sigqueue.3:28
7573 #: build/C/man3/sigqueue.3:28 build/C/man3/sigwait.3:26
7579 #: build/C/man3/sigqueue.3:31
7580 msgid "sigqueue - queue a signal and data to a process"
7584 #: build/C/man3/sigqueue.3:35
7586 "B<int sigqueue(pid_t >I<pid>B<, int >I<sig>B<, const union sigval "
7591 #: build/C/man3/sigqueue.3:43
7592 msgid "B<sigqueue>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
7596 #: build/C/man3/sigqueue.3:55
7598 "B<sigqueue>() sends the signal specified in I<sig> to the process whose PID "
7599 "is given in I<pid>. The permissions required to send a signal are the same "
7600 "as for B<kill>(2). As with B<kill>(2), the null signal (0) can be used to "
7601 "check if a process with a given PID exists."
7605 #: build/C/man3/sigqueue.3:60
7607 "The I<value> argument is used to specify an accompanying item of data "
7608 "(either an integer or a pointer value) to be sent with the signal, and has "
7609 "the following type:"
7613 #: build/C/man3/sigqueue.3:67
7618 " void *sival_ptr;\n"
7623 #: build/C/man3/sigqueue.3:83
7625 "If the receiving process has installed a handler for this signal using the "
7626 "B<SA_SIGINFO> flag to B<sigaction>(2), then it can obtain this data via the "
7627 "I<si_value> field of the I<siginfo_t> structure passed as the second "
7628 "argument to the handler. Furthermore, the I<si_code> field of that "
7629 "structure will be set to B<SI_QUEUE>."
7633 #: build/C/man3/sigqueue.3:91
7635 "On success, B<sigqueue>() returns 0, indicating that the signal was "
7636 "successfully queued to the receiving process. Otherwise, -1 is returned and "
7637 "I<errno> is set to indicate the error."
7641 #: build/C/man3/sigqueue.3:102
7642 msgid "I<sig> was invalid."
7646 #: build/C/man3/sigqueue.3:108
7648 "The process does not have permission to send the signal to the receiving "
7649 "process. For the required permissions, see B<kill>(2)."
7653 #: build/C/man3/sigqueue.3:112
7654 msgid "No process has a PID matching I<pid>."
7658 #: build/C/man3/sigqueue.3:114
7659 msgid "This system call first appeared in Linux 2.2."
7663 #: build/C/man3/sigqueue.3:119
7664 msgid "The B<sigqueue>() function is thread-safe."
7668 #: build/C/man3/sigqueue.3:129
7670 "If this function results in the sending of a signal to the process that "
7671 "invoked it, and that signal was not blocked by the calling thread, and no "
7672 "other threads were willing to handle this signal (either by having it "
7673 "unblocked, or by waiting for it using B<sigwait>(3)), then at least some "
7674 "signal must be delivered to this thread before this function returns."
7678 #: build/C/man3/sigqueue.3:144
7680 "On Linux, this function is implemented using the B<rt_sigqueueinfo>(2) "
7681 "system call. The system call differs in its third argument, which is the "
7682 "I<siginfo_t> structure that will be supplied to the receiving process's "
7683 "signal handler or returned by the receiving process's B<sigtimedwait>(2) "
7684 "call. Inside the glibc B<sigqueue>() wrapper, this argument, I<uinfo>, is "
7685 "initialized as follows:"
7689 #: build/C/man3/sigqueue.3:152
7692 "uinfo.si_signo = sig; /* Argument supplied to sigqueue() */\n"
7693 "uinfo.si_code = SI_QUEUE;\n"
7694 "uinfo.si_pid = getpid(); /* Process ID of sender */\n"
7695 "uinfo.si_uid = getuid(); /* Real UID of sender */\n"
7696 "uinfo.si_value = val; /* Argument supplied to sigqueue() */\n"
7700 #: build/C/man3/sigqueue.3:162
7702 "B<kill>(2), B<rt_sigqueueinfo>(2), B<sigaction>(2), B<signal>(2), "
7703 "B<pthread_sigqueue>(3), B<sigwait>(3), B<signal>(7)"
7707 #: build/C/man2/sigreturn.2:30
7713 #: build/C/man2/sigreturn.2:33
7714 msgid "sigreturn - return from signal handler and cleanup stack frame"
7718 #: build/C/man2/sigreturn.2:35
7719 msgid "B<int sigreturn(...);>"
7722 #. See arch/x86/kernel/signal.c::__setup_frame() [in 3.17 source code]
7724 #: build/C/man2/sigreturn.2:45
7726 "If the Linux kernel determines that an unblocked signal is pending for a "
7727 "process, then, at the next transition back to user mode in that process "
7728 "(e.g., upon return from a system call or when the process is rescheduled "
7729 "onto the CPU), it saves various pieces of process context (processor status "
7730 "word, registers, signal mask, and signal stack settings) into the "
7735 #: build/C/man2/sigreturn.2:52
7737 "The kernel also arranges that, during the transition back to user mode, the "
7738 "signal handler is called, and that, upon return from the handler, control "
7739 "passes to a piece of user-space code commonly called the \"signal "
7740 "trampoline\". The signal trampoline code in turn calls B<sigreturn>()."
7744 #: build/C/man2/sigreturn.2:65
7746 "This B<sigreturn>() call undoes everything that was done\\(emchanging the "
7747 "process's signal mask, switching signal stacks (see "
7748 "B<sigaltstack>(2))\\(emin order to invoke the signal handler. It restores "
7749 "the process's signal mask, switches stacks, and restores the process's "
7750 "context (processor flags and registers, including the stack pointer and "
7751 "instruction pointer), so that the process resumes execution at the point "
7752 "where it was interrupted by the signal."
7756 #: build/C/man2/sigreturn.2:68
7757 msgid "B<sigreturn>() never returns."
7761 #: build/C/man2/sigreturn.2:74
7763 "Many UNIX-type systems have a B<sigreturn>() system call or near "
7764 "equivalent. However, this call is not specified in POSIX, and details of "
7765 "its behavior vary across systems."
7769 #: build/C/man2/sigreturn.2:83
7771 "B<sigreturn>() exists only to allow the implementation of signal handlers. "
7772 "It should B<never> be called directly. Details of the arguments (if any) "
7773 "passed to B<sigreturn>() vary depending on the architecture."
7776 #. See, for example, sysdeps/unix/sysv/linux/i386/sigaction.c and
7777 #. sysdeps/unix/sysv/linux/x86_64/sigaction.c in the glibc (2.20) source.
7779 #: build/C/man2/sigreturn.2:106
7781 "Once upon a time, UNIX systems placed the signal trampoline code onto the "
7782 "user stack. Nowadays, pages of the user stack are protected so as to "
7783 "disallow code execution. Thus, on contemporary Linux systems, depending on "
7784 "the architecture, the signal trampoline code lives either in the B<vdso>(7) "
7785 "or in the C library. In the latter case, the C library supplies the "
7786 "location of the trampoline code using the I<sa_restorer> field of the "
7787 "I<sigaction> structure that is passed to B<sigaction>(2), and sets the "
7788 "B<SA_RESTORER> flag in the I<sa_flags> field."
7792 #: build/C/man2/sigreturn.2:115
7794 "The saved process context information is placed in a I<ucontext_t> structure "
7795 "(see I<E<lt>sys/ucontext.hE<gt>>). That structure is visible within the "
7796 "signal handler as the third argument of a handler established with the "
7797 "B<SA_SIGINFO> flag."
7801 #: build/C/man2/sigreturn.2:123
7803 "On some other UNIX systems, the operation of the signal trampoline differs a "
7804 "little. In particular, on some systems, upon transitioning back to user "
7805 "mode, the kernel passes control to the trampoline (rather than the signal "
7806 "handler), and the trampoline code calls the signal handler (and then calls "
7807 "B<sigreturn>() once the handler returns)."
7811 #: build/C/man2/sigreturn.2:130
7813 "B<kill>(2), B<restart_syscall>(2), B<sigaltstack>(2), B<signal>(2), "
7814 "B<getcontext>(3), B<signal>(7)"
7818 #: build/C/man3/sigset.3:26
7824 #: build/C/man3/sigset.3:29
7825 msgid "sigset, sighold, sigrelse, sigignore - System V signal API"
7829 #: build/C/man3/sigset.3:35
7830 msgid "B<sighandler_t sigset(int >I<sig>B<, sighandler_t >I<disp>B<);>"
7834 #: build/C/man3/sigset.3:37
7835 msgid "B<int sighold(int >I<sig>B<);>"
7839 #: build/C/man3/sigset.3:39
7840 msgid "B<int sigrelse(int >I<sig>B<);>"
7844 #: build/C/man3/sigset.3:41
7845 msgid "B<int sigignore(int >I<sig>B<);>"
7849 #: build/C/man3/sigset.3:52
7850 msgid "B<sigset>(), B<sighold>(), B<sigrelse>(), B<sigignore>():"
7854 #: build/C/man3/sigset.3:56
7855 msgid "_XOPEN_SOURCE\\ E<gt>=\\ 500 || _XOPEN_SOURCE\\ &&\\ _XOPEN_SOURCE_EXTENDED"
7859 #: build/C/man3/sigset.3:65
7861 "These functions are provided in glibc as a compatibility interface for "
7862 "programs that make use of the historical System V signal API. This API is "
7863 "obsolete: new applications should use the POSIX signal API (B<sigaction>(2), "
7864 "B<sigprocmask>(2), etc.)"
7868 #: build/C/man3/sigset.3:74
7870 "The B<sigset>() function modifies the disposition of the signal I<sig>. "
7871 "The I<disp> argument can be the address of a signal handler function, or one "
7872 "of the following constants:"
7876 #: build/C/man3/sigset.3:74
7882 #: build/C/man3/sigset.3:79
7883 msgid "Reset the disposition of I<sig> to the default."
7887 #: build/C/man3/sigset.3:79
7893 #: build/C/man3/sigset.3:83
7894 msgid "Ignore I<sig>."
7898 #: build/C/man3/sigset.3:83
7904 #: build/C/man3/sigset.3:90
7906 "Add I<sig> to the process's signal mask, but leave the disposition of I<sig> "
7911 #: build/C/man3/sigset.3:96
7913 "If I<disp> specifies the address of a signal handler, then I<sig> is added "
7914 "to the process's signal mask during execution of the handler."
7918 #: build/C/man3/sigset.3:104
7920 "If I<disp> was specified as a value other than B<SIG_HOLD>, then I<sig> is "
7921 "removed from the process's signal mask."
7925 #: build/C/man3/sigset.3:110 build/C/man3/sigvec.3:87
7926 msgid "The dispositions for B<SIGKILL> and B<SIGSTOP> cannot be changed."
7930 #: build/C/man3/sigset.3:116
7931 msgid "The B<sighold>() function adds I<sig> to the calling process's signal mask."
7935 #: build/C/man3/sigset.3:122
7937 "The B<sigrelse>() function removes I<sig> from the calling process's signal "
7942 #: build/C/man3/sigset.3:129
7943 msgid "The B<sigignore>() function sets the disposition of I<sig> to B<SIG_IGN>."
7947 #: build/C/man3/sigset.3:145
7949 "On success, B<sigset>() returns B<SIG_HOLD> if I<sig> was blocked before "
7950 "the call, or the signal's previous disposition if it was not blocked before "
7951 "the call. On error, B<sigset>() returns -1, with I<errno> set to indicate "
7952 "the error. (But see BUGS below.)"
7956 #: build/C/man3/sigset.3:154
7958 "The B<sighold>(), B<sigrelse>(), and B<sigignore>() functions return 0 on "
7959 "success; on error, these functions return -1 and set I<errno> to indicate "
7964 #: build/C/man3/sigset.3:161
7966 "For B<sigset>() see the ERRORS under B<sigaction>(2) and "
7967 "B<sigprocmask>(2)."
7971 #: build/C/man3/sigset.3:168
7972 msgid "For B<sighold>() and B<sigrelse>() see the ERRORS under B<sigprocmask>(2)."
7976 #: build/C/man3/sigset.3:173
7977 msgid "For B<sigignore>(), see the errors under B<sigaction>(2)."
7981 #: build/C/man3/sigset.3:190
7983 "SVr4, POSIX.1-2001. These functions are obsolete: do not use them in new "
7984 "programs. POSIX.1-2008 marks B<sighold>(), B<sigignore>(), B<sigpause>(), "
7985 "B<sigrelse>(), and B<sigset>() as obsolete, recommending the use of "
7986 "B<sigaction>(2), B<sigprocmask>(2), B<pthread_sigmask>(3), and "
7987 "B<sigsuspend>(2) instead."
7991 #: build/C/man3/sigset.3:192
7992 msgid "These functions appeared in glibc version 2.1."
7996 #: build/C/man3/sigset.3:198
7998 "The I<sighandler_t> type is a GNU extension; it is used on this page only to "
7999 "make the B<sigset>() prototype more easily readable."
8003 #: build/C/man3/sigset.3:206
8005 "The B<sigset>() function provides reliable signal handling semantics (as "
8006 "when calling B<sigaction>(2) with I<sa_mask> equal to 0)."
8010 #: build/C/man3/sigset.3:224
8012 "On System V, the B<signal>() function provides unreliable semantics (as "
8013 "when calling B<sigaction>(2) with I<sa_mask> equal to I<SA_RESETHAND | "
8014 "SA_NODEFER>). On BSD, B<signal>() provides reliable semantics. "
8015 "POSIX.1-2001 leaves these aspects of B<signal>() unspecified. See "
8016 "B<signal>(2) for further details."
8020 #: build/C/man3/sigset.3:232 build/C/man3/sigvec.3:272
8022 "In order to wait for a signal, BSD and System V both provided a function "
8023 "named B<sigpause>(3), but this function has a different argument on the two "
8024 "systems. See B<sigpause>(3) for details."
8028 #: build/C/man3/sigset.3:241
8030 "In versions of glibc before 2.2, B<sigset>() did not unblock I<sig> if "
8031 "I<disp> was specified as a value other than B<SIG_HOLD>."
8034 #. See http://sourceware.org/bugzilla/show_bug.cgi?id=1951
8036 #: build/C/man3/sigset.3:266
8038 "In versions of glibc before 2.5, B<sigset>() does not correctly return the "
8039 "previous disposition of the signal in two cases. First, if I<disp> is "
8040 "specified as B<SIG_HOLD>, then a successful B<sigset>() always returns "
8041 "B<SIG_HOLD>. Instead, it should return the previous disposition of the "
8042 "signal (unless the signal was blocked, in which case B<SIG_HOLD> should be "
8043 "returned). Second, if the signal is currently blocked, then the return "
8044 "value of a successful B<sigset>() should be B<SIG_HOLD>. Instead, the "
8045 "previous disposition of the signal is returned. These problems have been "
8046 "fixed since glibc 2.5."
8050 #: build/C/man3/sigset.3:276
8052 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
8053 "B<raise>(3), B<sigpause>(3), B<sigvec>(3), B<signal>(7)"
8057 #: build/C/man3/sigsetops.3:31
8063 #: build/C/man3/sigsetops.3:31
8069 #: build/C/man3/sigsetops.3:35
8071 "sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX signal "
8076 #: build/C/man3/sigsetops.3:39
8077 msgid "B<int sigemptyset(sigset_t *>I<set>B<);>"
8081 #: build/C/man3/sigsetops.3:41
8082 msgid "B<int sigfillset(sigset_t *>I<set>B<);>"
8086 #: build/C/man3/sigsetops.3:43
8087 msgid "B<int sigaddset(sigset_t *>I<set>B<, int >I<signum>B<);>"
8091 #: build/C/man3/sigsetops.3:45
8092 msgid "B<int sigdelset(sigset_t *>I<set>B<, int >I<signum>B<);>"
8096 #: build/C/man3/sigsetops.3:47
8097 msgid "B<int sigismember(const sigset_t *>I<set>B<, int >I<signum>B<);>"
8101 #: build/C/man3/sigsetops.3:59
8103 "B<sigemptyset>(), B<sigfillset>(), B<sigaddset>(), B<sigdelset>(), "
8108 #: build/C/man3/sigsetops.3:61
8109 msgid "_POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE"
8113 #: build/C/man3/sigsetops.3:65
8114 msgid "These functions allow the manipulation of POSIX signal sets."
8118 #: build/C/man3/sigsetops.3:70
8120 "B<sigemptyset>() initializes the signal set given by I<set> to empty, with "
8121 "all signals excluded from the set."
8125 #: build/C/man3/sigsetops.3:75
8126 msgid "B<sigfillset>() initializes I<set> to full, including all signals."
8130 #: build/C/man3/sigsetops.3:83
8132 "B<sigaddset>() and B<sigdelset>() add and delete respectively signal "
8133 "I<signum> from I<set>."
8137 #: build/C/man3/sigsetops.3:89
8138 msgid "B<sigismember>() tests whether I<signum> is a member of I<set>."
8142 #: build/C/man3/sigsetops.3:107
8144 "Objects of type I<sigset_t> must be initialized by a call to either "
8145 "B<sigemptyset>() or B<sigfillset>() before being passed to the functions "
8146 "B<sigaddset>(), B<sigdelset>() and B<sigismember>() or the additional "
8147 "glibc functions described below (B<sigisemptyset>(), B<sigandset>(), and "
8148 "B<sigorset>()). The results are undefined if this is not done."
8152 #: build/C/man3/sigsetops.3:114
8154 "B<sigemptyset>(), B<sigfillset>(), B<sigaddset>(), and B<sigdelset>() "
8155 "return 0 on success and -1 on error."
8159 #: build/C/man3/sigsetops.3:123
8161 "B<sigismember>() returns 1 if I<signum> is a member of I<set>, 0 if "
8162 "I<signum> is not a member, and -1 on error."
8166 #: build/C/man3/sigsetops.3:127
8167 msgid "On error, these functions set I<errno> to indicate the cause of the error."
8171 #: build/C/man3/sigsetops.3:132
8172 msgid "I<sig> is not a valid signal."
8176 #: build/C/man3/sigsetops.3:145
8178 "The B<sigemptyset>(), B<sigfillset>(), B<sigaddset>(), B<sigdelset>(), "
8179 "B<sigismember>(), B<sigisemptyset>(), B<sigorset>(), and B<sigandset>() "
8180 "functions are thread-safe."
8184 #: build/C/man3/sigsetops.3:148
8190 #: build/C/man3/sigsetops.3:154
8192 "If the B<_GNU_SOURCE> feature test macro is defined, then "
8193 "I<E<lt>signal.hE<gt>> exposes three other functions for manipulating signal "
8198 #: build/C/man3/sigsetops.3:161
8201 "B<int sigisemptyset(const sigset_t *>I<set>B<);>\n"
8202 "B<int sigorset(sigset_t *>I<dest>B<, const sigset_t *>I<left>B<,>\n"
8203 "B< const sigset_t *>I<right>B<);>\n"
8204 "B<int sigandset(sigset_t *>I<dest>B<, const sigset_t *>I<left>B<,>\n"
8205 "B< const sigset_t *>I<right>B<);>\n"
8209 #: build/C/man3/sigsetops.3:167
8211 "B<sigisemptyset>() returns 1 if I<set> contains no signals, and 0 "
8216 #: build/C/man3/sigsetops.3:183
8218 "B<sigorset>() places the union of the sets I<left> and I<right> in "
8219 "I<dest>. B<sigandset>() places the intersection of the sets I<left> and "
8220 "I<right> in I<dest>. Both functions return 0 on success, and -1 on failure."
8224 #: build/C/man3/sigsetops.3:186
8226 "These functions are nonstandard (a few other systems provide similar "
8227 "functions) and their use should be avoided in portable applications."
8231 #: build/C/man3/sigsetops.3:191
8232 msgid "B<sigaction>(2), B<sigpending>(2), B<sigprocmask>(2), B<sigsuspend>(2)"
8236 #: build/C/man2/sigsuspend.2:29
8242 #: build/C/man2/sigsuspend.2:32
8243 msgid "sigsuspend - wait for a signal"
8247 #: build/C/man2/sigsuspend.2:36
8248 msgid "B<int sigsuspend(const sigset_t *>I<mask>B<);>"
8252 #: build/C/man2/sigsuspend.2:45
8254 "B<sigsuspend>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
8259 #: build/C/man2/sigsuspend.2:53
8261 "B<sigsuspend>() temporarily replaces the signal mask of the calling process "
8262 "with the mask given by I<mask> and then suspends the process until delivery "
8263 "of a signal whose action is to invoke a signal handler or to terminate a "
8268 #: build/C/man2/sigsuspend.2:62
8270 "If the signal terminates the process, then B<sigsuspend>() does not "
8271 "return. If the signal is caught, then B<sigsuspend>() returns after the "
8272 "signal handler returns, and the signal mask is restored to the state before "
8273 "the call to B<sigsuspend>()."
8277 #: build/C/man2/sigsuspend.2:70
8279 "It is not possible to block B<SIGKILL> or B<SIGSTOP>; specifying these "
8280 "signals in I<mask>, has no effect on the process's signal mask."
8284 #: build/C/man2/sigsuspend.2:76
8286 "B<sigsuspend>() always returns -1, with I<errno> set to indicate the error "
8287 "(normally, B<EINTR>)."
8291 #: build/C/man2/sigsuspend.2:81
8293 "I<mask> points to memory which is not a valid part of the process address "
8298 #: build/C/man2/sigsuspend.2:84
8299 msgid "The call was interrupted by a signal."
8303 #: build/C/man2/sigsuspend.2:104
8305 "Normally, B<sigsuspend>() is used in conjunction with B<sigprocmask>(2) in "
8306 "order to prevent delivery of a signal during the execution of a critical "
8307 "code section. The caller first blocks the signals with B<sigprocmask>(2). "
8308 "When the critical code has completed, the caller then waits for the signals "
8309 "by calling B<sigsuspend>() with the signal mask that was returned by "
8310 "B<sigprocmask>(2) (in the I<oldset> argument)."
8314 #: build/C/man2/sigsuspend.2:118
8316 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
8317 "B<sigwaitinfo>(2), B<sigsetops>(3), B<sigwait>(3), B<signal>(7)"
8321 #: build/C/man3/sigvec.3:26
8327 #: build/C/man3/sigvec.3:29
8328 msgid "sigvec, sigblock, sigsetmask, siggetmask, sigmask - BSD signal API"
8332 #: build/C/man3/sigvec.3:33
8334 "B<int sigvec(int >I<sig>B<, const struct sigvec *>I<vec>B<, struct sigvec "
8339 #: build/C/man3/sigvec.3:35
8340 msgid "B<int sigmask(int >I<signum>B<);>"
8344 #: build/C/man3/sigvec.3:37
8345 msgid "B<int sigblock(int >I<mask>B<);>"
8349 #: build/C/man3/sigvec.3:39
8350 msgid "B<int sigsetmask(int >I<mask>B<);>"
8354 #: build/C/man3/sigvec.3:41
8355 msgid "B<int siggetmask(void);>"
8359 #: build/C/man3/sigvec.3:49
8360 msgid "All functions shown above: _BSD_SOURCE"
8364 #: build/C/man3/sigvec.3:56
8366 "These functions are provided in glibc as a compatibility interface for "
8367 "programs that make use of the historical BSD signal API. This API is "
8368 "obsolete: new applications should use the POSIX signal API (B<sigaction>(2), "
8369 "B<sigprocmask>(2), etc.)."
8373 #: build/C/man3/sigvec.3:81
8375 "The B<sigvec>() function sets and/or gets the disposition of the signal "
8376 "I<sig> (like the POSIX B<sigaction>(2)). If I<vec> is not NULL, it points "
8377 "to a I<sigvec> structure that defines the new disposition for I<sig>. If "
8378 "I<ovec> is not NULL, it points to a I<sigvec> structure that is used to "
8379 "return the previous disposition of I<sig>. To obtain the current "
8380 "disposition of I<sig> without changing it, specify NULL for I<vec>, and a "
8381 "non-null pointer for I<ovec>."
8385 #: build/C/man3/sigvec.3:91
8386 msgid "The I<sigvec> structure has the following form:"
8390 #: build/C/man3/sigvec.3:99
8394 " void (*sv_handler)(int); /* Signal disposition */\n"
8395 " int sv_mask; /* Signals to be blocked in handler */\n"
8396 " int sv_flags; /* Flags */\n"
8401 #: build/C/man3/sigvec.3:110
8403 "The I<sv_handler> field specifies the disposition of the signal, and is "
8404 "either: the address of a signal handler function; B<SIG_DFL>, meaning the "
8405 "default disposition applies for the signal; or B<SIG_IGN>, meaning that the "
8406 "signal is ignored."
8410 #: build/C/man3/sigvec.3:124
8412 "If I<sv_handler> specifies the address of a signal handler, then I<sv_mask> "
8413 "specifies a mask of signals that are to be blocked while the handler is "
8414 "executing. In addition, the signal for which the handler is invoked is also "
8415 "blocked. Attempts to block B<SIGKILL> or B<SIGSTOP> are silently ignored."
8419 #: build/C/man3/sigvec.3:131
8421 "If I<sv_handler> specifies the address of a signal handler, then the "
8422 "I<sv_flags> field specifies flags controlling what happens when the handler "
8423 "is called. This field may contain zero or more of the following flags:"
8427 #: build/C/man3/sigvec.3:131
8429 msgid "B<SV_INTERRUPT>"
8433 #: build/C/man3/sigvec.3:139
8435 "If the signal handler interrupts a blocking system call, then upon return "
8436 "from the handler the system call will not be restarted: instead it will fail "
8437 "with the error B<EINTR>. If this flag is not specified, then system calls "
8438 "are restarted by default."
8442 #: build/C/man3/sigvec.3:139
8444 msgid "B<SV_RESETHAND>"
8448 #: build/C/man3/sigvec.3:148
8450 "Reset the disposition of the signal to the default before calling the signal "
8451 "handler. If this flag is not specified, then the handler remains "
8452 "established until explicitly removed by a later call to B<sigvec>() or "
8453 "until the process performs an B<execve>(2)."
8457 #: build/C/man3/sigvec.3:148
8459 msgid "B<SV_ONSTACK>"
8463 #: build/C/man3/sigvec.3:155
8465 "Handle the signal on the alternate signal stack (historically established "
8466 "under BSD using the obsolete B<sigstack>() function; the POSIX replacement "
8467 "is B<sigaltstack>(2))."
8471 #: build/C/man3/sigvec.3:165
8473 "The B<sigmask>() macro constructs and returns a \"signal mask\" for "
8474 "I<signum>. For example, we can initialize the I<vec.sv_mask> field given to "
8475 "B<sigvec>() using code such as the following:"
8479 #: build/C/man3/sigvec.3:170
8482 " vec.sv_mask = sigmask(SIGQUIT) | sigmask(SIGABRT);\n"
8483 " /* Block SIGQUIT and SIGABRT during\n"
8484 " handler execution */\n"
8488 #: build/C/man3/sigvec.3:185
8490 "The B<sigblock>() function adds the signals in I<mask> to the process's "
8491 "signal mask (like POSIX I<sigprocmask(SIG_BLOCK)>), and returns the "
8492 "process's previous signal mask. Attempts to block B<SIGKILL> or B<SIGSTOP> "
8493 "are silently ignored."
8497 #: build/C/man3/sigvec.3:193
8499 "The B<sigsetmask>() function sets the process's signal mask to the value "
8500 "given in I<mask> (like POSIX I<sigprocmask(SIG_SETMASK)>), and returns the "
8501 "process's previous signal mask."
8505 #: build/C/man3/sigvec.3:199
8507 "The B<siggetmask>() function returns the process's current signal mask. "
8508 "This call is equivalent to I<sigblock(0)>."
8512 #: build/C/man3/sigvec.3:205
8514 "The B<sigvec>() function returns 0 on success; on error, it returns -1 and "
8515 "sets I<errno> to indicate the error."
8519 #: build/C/man3/sigvec.3:211
8521 "The B<sigblock>() and B<sigsetmask>() functions return the previous signal "
8526 #: build/C/man3/sigvec.3:216
8527 msgid "The B<sigmask>() macro returns the signal mask for I<signum>."
8531 #: build/C/man3/sigvec.3:221
8532 msgid "See the ERRORS under B<sigaction>(2) and B<sigprocmask>(2)."
8536 #: build/C/man3/sigvec.3:230
8538 "The B<sigvec>(), B<sigblock>(), B<sigsetmask>(), and B<siggetmask>() "
8539 "functions are thread-safe."
8543 #: build/C/man3/sigvec.3:234
8544 msgid "The B<sigmask>() macro is thread-safe."
8548 #: build/C/man3/sigvec.3:241
8550 "Starting with version 2.21, the GNU C library no longer exports the "
8551 "B<sigvec>() function as part of the ABI. (To ensure backward "
8552 "compatibility, the glibc symbol versioning scheme continues to export the "
8553 "interface to binaries linked against older versions of the library.)"
8557 #: build/C/man3/sigvec.3:247
8559 "All of these functions were in 4.3BSD, except B<siggetmask>(), whose origin "
8560 "is unclear. These functions are obsolete: do not use them in new programs."
8564 #: build/C/man3/sigvec.3:264
8566 "On 4.3BSD, the B<signal>() function provided reliable semantics (as when "
8567 "calling B<sigvec>() with I<vec.sv_mask> equal to 0). On System V, "
8568 "B<signal>() provides unreliable semantics. POSIX.1-2001 leaves these "
8569 "aspects of B<signal>() unspecified. See B<signal>(2) for further details."
8573 #: build/C/man3/sigvec.3:282
8575 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
8576 "B<raise>(3), B<sigpause>(3), B<sigset>(3), B<signal>(7)"
8580 #: build/C/man3/sigwait.3:26
8586 #: build/C/man3/sigwait.3:29
8587 msgid "sigwait - wait for a signal"
8591 #: build/C/man3/sigwait.3:34
8593 msgid "B< int sigwait(const sigset_t *>I<set>B<, int *>I<sig>B<);>\n"
8597 #: build/C/man3/sigwait.3:44
8598 msgid "B<sigwait>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE"
8602 #: build/C/man3/sigwait.3:56
8604 "The B<sigwait>() function suspends execution of the calling thread until "
8605 "one of the signals specified in the signal set I<set> becomes pending. The "
8606 "function accepts the signal (removes it from the pending list of signals), "
8607 "and returns the signal number in I<sig>."
8611 #: build/C/man3/sigwait.3:62
8613 "The operation of B<sigwait>() is the same as B<sigwaitinfo>(2), except "
8618 #: build/C/man3/sigwait.3:67
8620 "B<sigwait>() returns only the signal number, rather than a I<siginfo_t> "
8621 "structure describing the signal."
8625 #: build/C/man3/sigwait.3:69
8626 msgid "The return values of the two functions are different."
8630 #: build/C/man3/sigwait.3:74
8632 "On success, B<sigwait>() returns 0. On error, it returns a positive error "
8633 "number (listed in ERRORS)."
8636 #. Does not occur for glibc.
8638 #: build/C/man3/sigwait.3:80
8639 msgid "I<set> contains an invalid signal number."
8643 #: build/C/man3/sigwait.3:85
8644 msgid "The B<sigwait>() function is thread-safe."
8648 #: build/C/man3/sigwait.3:91
8649 msgid "B<sigwait>() is implemented using B<sigtimedwait>(2)."
8653 #: build/C/man3/sigwait.3:94
8654 msgid "See B<pthread_sigmask>(3)."
8658 #: build/C/man3/sigwait.3:102
8660 "B<sigaction>(2), B<signalfd>(2), B<sigpending>(2), B<sigsuspend>(2), "
8661 "B<sigwaitinfo>(2), B<sigsetops>(3), B<signal>(7)"
8665 #: build/C/man2/sigwaitinfo.2:25
8671 #: build/C/man2/sigwaitinfo.2:28
8672 msgid "sigwaitinfo, sigtimedwait - synchronously wait for queued signals"
8676 #: build/C/man2/sigwaitinfo.2:33
8678 msgid "B<int sigwaitinfo(const sigset_t *>I<set>B<, siginfo_t *>I<info>B<);>\n"
8682 #: build/C/man2/sigwaitinfo.2:36
8685 "B<int sigtimedwait(const sigset_t *>I<set>B<, siginfo_t *>I<info>B<, >\n"
8686 "B< const struct timespec *>I<timeout>B<);>\n"
8690 #: build/C/man2/sigwaitinfo.2:46
8691 msgid "B<sigwaitinfo>(), B<sigtimedwait>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
8695 #: build/C/man2/sigwaitinfo.2:56
8697 "B<sigwaitinfo>() suspends execution of the calling thread until one of the "
8698 "signals in I<set> is pending (If one of the signals in I<set> is already "
8699 "pending for the calling thread, B<sigwaitinfo>() will return immediately.)"
8703 #: build/C/man2/sigwaitinfo.2:68
8705 "B<sigwaitinfo>() removes the signal from the set of pending signals and "
8706 "returns the signal number as its function result. If the I<info> argument "
8707 "is not NULL, then the buffer that it points to is used to return a structure "
8708 "of type I<siginfo_t> (see B<sigaction>(2)) containing information about the "
8713 #: build/C/man2/sigwaitinfo.2:76
8715 "If multiple signals in I<set> are pending for the caller, the signal that is "
8716 "retrieved by B<sigwaitinfo>() is determined according to the usual ordering "
8717 "rules; see B<signal>(7) for further details."
8721 #: build/C/man2/sigwaitinfo.2:88
8723 "B<sigtimedwait>() operates in exactly the same way as B<sigwaitinfo>() "
8724 "except that it has an additional argument, I<timeout>, which specifies the "
8725 "interval for which the thread is suspended waiting for a signal. (This "
8726 "interval will be rounded up to the system clock granularity, and kernel "
8727 "scheduling delays mean that the interval may overrun by a small amount.) "
8728 "This argument is of the following type:"
8732 #: build/C/man2/sigwaitinfo.2:95
8735 "struct timespec {\n"
8736 " long tv_sec; /* seconds */\n"
8737 " long tv_nsec; /* nanoseconds */\n"
8742 #: build/C/man2/sigwaitinfo.2:105
8744 "If both fields of this structure are specified as 0, a poll is performed: "
8745 "B<sigtimedwait>() returns immediately, either with information about a "
8746 "signal that was pending for the caller, or with an error if none of the "
8747 "signals in I<set> was pending."
8751 #: build/C/man2/sigwaitinfo.2:114
8753 "On success, both B<sigwaitinfo>() and B<sigtimedwait>() return a signal "
8754 "number (i.e., a value greater than zero). On failure both calls return -1, "
8755 "with I<errno> set to indicate the error."
8759 #: build/C/man2/sigwaitinfo.2:123
8761 "No signal in I<set> was became pending within the I<timeout> period "
8762 "specified to B<sigtimedwait>()."
8766 #: build/C/man2/sigwaitinfo.2:129
8768 "The wait was interrupted by a signal handler; see B<signal>(7). (This "
8769 "handler was for a signal other than one of those in I<set>.)"
8773 #: build/C/man2/sigwaitinfo.2:133
8774 msgid "I<timeout> was invalid."
8778 #: build/C/man2/sigwaitinfo.2:153
8780 "In normal usage, the calling program blocks the signals in I<set> via a "
8781 "prior call to B<sigprocmask>(2) (so that the default disposition for these "
8782 "signals does not occur if they become pending between successive calls to "
8783 "B<sigwaitinfo>() or B<sigtimedwait>()) and does not establish handlers for "
8784 "these signals. In a multithreaded program, the signal should be blocked in "
8785 "all threads, in order to prevent the signal being treated according to its "
8786 "default disposition in a thread other than the one calling B<sigwaitinfo>() "
8787 "or B<sigtimedwait>())."
8791 #: build/C/man2/sigwaitinfo.2:158
8793 "The set of signals that is pending for a given thread is the union of the "
8794 "set of signals that is pending specifically for that thread and the set of "
8795 "signals that is pending for the process as a whole (see B<signal>(7))."
8799 #: build/C/man2/sigwaitinfo.2:164
8800 msgid "Attempts to wait for B<SIGKILL> and B<SIGSTOP> are silently ignored."
8804 #: build/C/man2/sigwaitinfo.2:173
8806 "If multiple threads of a process are blocked waiting for the same signal(s) "
8807 "in B<sigwaitinfo>() or B<sigtimedwait>(), then exactly one of the threads "
8808 "will actually receive the signal if it becomes pending for the process as a "
8809 "whole; which of the threads receives the signal is indeterminate."
8813 #: build/C/man2/sigwaitinfo.2:183
8815 "POSIX leaves the meaning of a NULL value for the I<timeout> argument of "
8816 "B<sigtimedwait>() unspecified, permitting the possibility that this has the "
8817 "same meaning as a call to B<sigwaitinfo>(), and indeed this is what is done "
8822 #: build/C/man2/sigwaitinfo.2:188
8824 "On Linux, B<sigwaitinfo>() is a library function implemented on top of "
8825 "B<sigtimedwait>()."
8829 #: build/C/man2/sigwaitinfo.2:201
8831 "The raw B<sigtimedwait>() system call has a fifth argument, I<size_t "
8832 "sigsetsize>, which specifies the size in bytes of the I<set> argument. The "
8833 "glibc B<sigtimedwait>() wrapper function specifies this argument as a fixed "
8834 "value (equal to I<sizeof(sigset_t)>)."
8838 #: build/C/man2/sigwaitinfo.2:213
8840 "B<kill>(2), B<sigaction>(2), B<signal>(2), B<signalfd>(2), B<sigpending>(2), "
8841 "B<sigprocmask>(2), B<sigqueue>(3), B<sigsetops>(3), B<sigwait>(3), "
8842 "B<signal>(7), B<time>(7)"
8846 #: build/C/man3/sysv_signal.3:25
8852 #: build/C/man3/sysv_signal.3:25
8858 #: build/C/man3/sysv_signal.3:28
8859 msgid "sysv_signal - signal handling with System V semantics"
8863 #: build/C/man3/sysv_signal.3:30
8864 msgid "B<#define _GNU_SOURCE> /* See feature_test_macros(7) */"
8868 #: build/C/man3/sysv_signal.3:36
8869 msgid "B<sighandler_t sysv_signal(int >I<signum>B<, sighandler_t >I<handler>B<);>"
8873 #: build/C/man3/sysv_signal.3:41
8875 "The B<sysv_signal>() function takes the same arguments, and performs the "
8876 "same task, as B<signal>(2)."
8880 #: build/C/man3/sysv_signal.3:51
8882 "However B<sysv_signal>() provides the System V unreliable signal semantics, "
8883 "that is: a) the disposition of the signal is reset to the default when the "
8884 "handler is invoked; b) delivery of further instances of the signal is not "
8885 "blocked while the signal handler is executing; and c) if the handler "
8886 "interrupts (certain) blocking system calls, then the system call is not "
8887 "automatically restarted."
8891 #: build/C/man3/sysv_signal.3:57
8893 "The B<sysv_signal>() function returns the previous value of the signal "
8894 "handler, or B<SIG_ERR> on error."
8898 #: build/C/man3/sysv_signal.3:65
8899 msgid "The B<sysv_signal>() function is thread-safe."
8903 #: build/C/man3/sysv_signal.3:67
8904 msgid "This function is nonstandard."
8908 #: build/C/man3/sysv_signal.3:73
8909 msgid "Use of B<sysv_signal>() should be avoided; use B<sigaction>(2) instead."
8913 #: build/C/man3/sysv_signal.3:84
8915 "On older Linux systems, B<sysv_signal>() and B<signal>(2) were "
8916 "equivalent. But on newer systems, B<signal>(2) provides reliable signal "
8917 "semantics; see B<signal>(2) for details."
8921 #: build/C/man3/sysv_signal.3:97
8922 msgid "B<sigaction>(2), B<signal>(2), B<bsd_signal>(3), B<signal>(7)"
8926 #: build/C/man2/timer_create.2:33
8928 msgid "TIMER_CREATE"
8932 #: build/C/man2/timer_create.2:36
8933 msgid "timer_create - create a POSIX per-process timer"
8937 #: build/C/man2/timer_create.2:40
8940 "B<#include E<lt>signal.hE<gt>>\n"
8941 "B<#include E<lt>time.hE<gt>>\n"
8945 #: build/C/man2/timer_create.2:43
8948 "B<int timer_create(clockid_t >I<clockid>B<, struct sigevent *>I<sevp>B<,>\n"
8949 "B< timer_t *>I<timerid>B<);>\n"
8953 #: build/C/man2/timer_create.2:46 build/C/man2/timer_delete.2:37 build/C/man2/timer_getoverrun.2:37 build/C/man2/timer_settime.2:41
8954 msgid "Link with I<-lrt>."
8958 #: build/C/man2/timer_create.2:54
8959 msgid "B<timer_create>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
8963 #: build/C/man2/timer_create.2:62
8965 "B<timer_create>() creates a new per-process interval timer. The ID of the "
8966 "new timer is returned in the buffer pointed to by I<timerid>, which must be "
8967 "a non-null pointer. This ID is unique within the process, until the timer "
8968 "is deleted. The new timer is initially disarmed."
8972 #: build/C/man2/timer_create.2:67
8974 "The I<clockid> argument specifies the clock that the new timer uses to "
8975 "measure time. It can be specified as one of the following values:"
8979 #: build/C/man2/timer_create.2:67
8981 msgid "B<CLOCK_REALTIME>"
8985 #: build/C/man2/timer_create.2:70
8986 msgid "A settable system-wide real-time clock."
8990 #: build/C/man2/timer_create.2:70
8992 msgid "B<CLOCK_MONOTONIC>"
8995 #. Note: the CLOCK_MONOTONIC_RAW clock added for clock_gettime()
8996 #. in 2.6.28 is not supported for POSIX timers -- mtk, Feb 2009
8998 #: build/C/man2/timer_create.2:77
9000 "A nonsettable monotonically increasing clock that measures time from some "
9001 "unspecified point in the past that does not change after system startup."
9005 #: build/C/man2/timer_create.2:77
9007 msgid "B<CLOCK_PROCESS_CPUTIME_ID> (since Linux 2.6.12)"
9011 #: build/C/man2/timer_create.2:81
9013 "A clock that measures (user and system) CPU time consumed by (all of the "
9014 "threads in) the calling process."
9018 #: build/C/man2/timer_create.2:81
9020 msgid "B<CLOCK_THREAD_CPUTIME_ID> (since Linux 2.6.12)"
9023 #. The CLOCK_MONOTONIC_RAW that was added in 2.6.28 can't be used
9024 #. to create a timer -- mtk, Feb 2009
9026 #: build/C/man2/timer_create.2:87
9028 "A clock that measures (user and system) CPU time consumed by the calling "
9033 #: build/C/man2/timer_create.2:96
9035 "As well as the above values, I<clockid> can be specified as the I<clockid> "
9036 "returned by a call to B<clock_getcpuclockid>(3) or "
9037 "B<pthread_getcpuclockid>(3)."
9041 #: build/C/man2/timer_create.2:105
9043 "The I<sevp> argument points to a I<sigevent> structure that specifies how "
9044 "the caller should be notified when the timer expires. For the definition "
9045 "and general details of this structure, see B<sigevent>(7)."
9049 #: build/C/man2/timer_create.2:109
9050 msgid "The I<sevp.sigev_notify> field can have the following values:"
9054 #: build/C/man2/timer_create.2:114
9056 "Don't asynchronously notify when the timer expires. Progress of the timer "
9057 "can be monitored using B<timer_gettime>(2)."
9061 #: build/C/man2/timer_create.2:132
9063 "Upon timer expiration, generate the signal I<sigev_signo> for the process. "
9064 "See B<sigevent>(7) for general details. The I<si_code> field of the "
9065 "I<siginfo_t> structure will be set to B<SI_TIMER>. At any point in time, at "
9066 "most one signal is queued to the process for a given timer; see "
9067 "B<timer_getoverrun>(2) for more details."
9071 #: build/C/man2/timer_create.2:140
9073 "Upon timer expiration, invoke I<sigev_notify_function> as if it were the "
9074 "start function of a new thread. See B<sigevent>(7) for details."
9078 #: build/C/man2/timer_create.2:154
9080 "As for B<SIGEV_SIGNAL>, but the signal is targeted at the thread whose ID is "
9081 "given in I<sigev_notify_thread_id>, which must be a thread in the same "
9082 "process as the caller. The I<sigev_notify_thread_id> field specifies a "
9083 "kernel thread ID, that is, the value returned by B<clone>(2) or "
9084 "B<gettid>(2). This flag is intended only for use by threading libraries."
9088 #: build/C/man2/timer_create.2:169
9090 "Specifying I<sevp> as NULL is equivalent to specifying a pointer to a "
9091 "I<sigevent> structure in which I<sigev_notify> is B<SIGEV_SIGNAL>, "
9092 "I<sigev_signo> is B<SIGALRM>, and I<sigev_value.sival_int> is the timer ID."
9096 #: build/C/man2/timer_create.2:177
9098 "On success, B<timer_create>() returns 0, and the ID of the new timer is "
9099 "placed in I<*timerid>. On failure, -1 is returned, and I<errno> is set to "
9100 "indicate the error."
9104 #: build/C/man2/timer_create.2:181
9105 msgid "Temporary error during kernel allocation of timer structures."
9109 #: build/C/man2/timer_create.2:189
9111 "Clock ID, I<sigev_notify>, I<sigev_signo>, or I<sigev_notify_thread_id> is "
9115 #. glibc layer: malloc()
9117 #: build/C/man2/timer_create.2:193
9118 msgid "Could not allocate memory."
9122 #: build/C/man2/timer_create.2:195 build/C/man2/timer_delete.2:67 build/C/man2/timer_getoverrun.2:97
9123 msgid "This system call is available since Linux 2.6."
9127 #: build/C/man2/timer_create.2:200
9128 msgid "A program may create multiple interval timers using B<timer_create>()."
9132 #: build/C/man2/timer_create.2:205
9134 "Timers are not inherited by the child of a B<fork>(2), and are disarmed and "
9135 "deleted during an B<execve>(2)."
9139 #: build/C/man2/timer_create.2:213
9141 "The kernel preallocates a \"queued real-time signal\" for each timer created "
9142 "using B<timer_create>(). Consequently, the number of timers is limited by "
9143 "the B<RLIMIT_SIGPENDING> resource limit (see B<setrlimit>(2))."
9147 #: build/C/man2/timer_create.2:218
9149 "The timers created by B<timer_create>() are commonly known as \"POSIX "
9150 "(interval) timers\". The POSIX timers API consists of the following "
9155 #: build/C/man2/timer_create.2:221
9156 msgid "B<timer_create>(): Create a timer."
9160 #: build/C/man2/timer_create.2:224
9161 msgid "B<timer_settime>(2): Arm (start) or disarm (stop) a timer."
9165 #: build/C/man2/timer_create.2:228
9167 "B<timer_gettime>(2): Fetch the time remaining until the next expiration of a "
9168 "timer, along with the interval setting of the timer."
9172 #: build/C/man2/timer_create.2:231
9174 "B<timer_getoverrun>(2): Return the overrun count for the last timer "
9179 #: build/C/man2/timer_create.2:234
9180 msgid "B<timer_delete>(2): Disarm and delete a timer."
9184 #: build/C/man2/timer_create.2:243
9186 "Since Linux 3.10, the I</proc/[pid]/timers> file can be used to list the "
9187 "POSIX timers for the process with PID I<pid>. See B<proc>(5) for further "
9192 #: build/C/man2/timer_create.2:246
9194 "Part of the implementation of the POSIX timers API is provided by glibc. In "
9199 #: build/C/man2/timer_create.2:250
9201 "The functionality for B<SIGEV_THREAD> is implemented within glibc, rather "
9205 #. See the glibc source file kernel-posix-timers.h for the structure
9206 #. that glibc uses to map user-space timer IDs to kernel timer IDs
9207 #. The kernel-level timer ID is exposed via siginfo.si_tid.
9209 #: build/C/man2/timer_create.2:256
9211 "The timer IDs presented at user level are maintained by glibc, which maps "
9212 "these IDs to the timer IDs employed by the kernel."
9216 #: build/C/man2/timer_create.2:264
9218 "The POSIX timers system calls first appeared in Linux 2.6. Prior to this, "
9219 "glibc provided an incomplete user-space implementation (B<CLOCK_REALTIME> "
9220 "timers only) using POSIX threads, and current glibc falls back to this "
9221 "implementation on systems running pre-2.6 Linux kernels."
9225 #: build/C/man2/timer_create.2:276
9227 "The program below takes two arguments: a sleep period in seconds, and a "
9228 "timer frequency in nanoseconds. The program establishes a handler for the "
9229 "signal it uses for the timer, blocks that signal, creates and arms a timer "
9230 "that expires with the given frequency, sleeps for the specified number of "
9231 "seconds, and then unblocks the timer signal. Assuming that the timer "
9232 "expired at least once while the program slept, the signal handler will be "
9233 "invoked, and the handler displays some information about the timer "
9234 "notification. The program terminates after one invocation of the signal "
9239 #: build/C/man2/timer_create.2:281
9241 "In the following example run, the program sleeps for 1 second, after "
9242 "creating a timer that has a frequency of 100 nanoseconds. By the time the "
9243 "signal is unblocked and delivered, there have been around ten million "
9248 #: build/C/man2/timer_create.2:293
9251 "$ B<./a.out 1 100>\n"
9252 "Establishing handler for signal 34\n"
9253 "Blocking signal 34\n"
9254 "timer ID is 0x804c008\n"
9255 "Sleeping for 1 seconds\n"
9256 "Unblocking signal 34\n"
9257 "Caught signal 34\n"
9258 " sival_ptr = 0xbfb174f4; *sival_ptr = 0x804c008\n"
9259 " overrun count = 10004886\n"
9263 #: build/C/man2/timer_create.2:303
9266 "#include E<lt>stdlib.hE<gt>\n"
9267 "#include E<lt>unistd.hE<gt>\n"
9268 "#include E<lt>stdio.hE<gt>\n"
9269 "#include E<lt>signal.hE<gt>\n"
9270 "#include E<lt>time.hE<gt>\n"
9274 #: build/C/man2/timer_create.2:306
9277 "#define CLOCKID CLOCK_REALTIME\n"
9278 "#define SIG SIGRTMIN\n"
9282 #: build/C/man2/timer_create.2:309
9285 "#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \\e\n"
9290 #: build/C/man2/timer_create.2:315
9294 "print_siginfo(siginfo_t *si)\n"
9301 #: build/C/man2/timer_create.2:317
9303 msgid " tidp = si-E<gt>si_value.sival_ptr;\n"
9307 #: build/C/man2/timer_create.2:320
9310 " printf(\" sival_ptr = %p; \", si-E<gt>si_value.sival_ptr);\n"
9311 " printf(\" *sival_ptr = 0x%lx\\en\", (long) *tidp);\n"
9315 #: build/C/man2/timer_create.2:327
9318 " or = timer_getoverrun(*tidp);\n"
9320 " errExit(\"timer_getoverrun\");\n"
9322 " printf(\" overrun count = %d\\en\", or);\n"
9327 #: build/C/man2/timer_create.2:334
9331 "handler(int sig, siginfo_t *si, void *uc)\n"
9333 " /* Note: calling printf() from a signal handler is not\n"
9334 " strictly correct, since printf() is not async-signal-safe;\n"
9335 " see signal(7) */\n"
9339 #: build/C/man2/timer_create.2:339
9342 " printf(\"Caught signal %d\\en\", sig);\n"
9343 " print_siginfo(si);\n"
9344 " signal(sig, SIG_IGN);\n"
9349 #: build/C/man2/timer_create.2:349
9353 "main(int argc, char *argv[])\n"
9355 " timer_t timerid;\n"
9356 " struct sigevent sev;\n"
9357 " struct itimerspec its;\n"
9358 " long long freq_nanosecs;\n"
9360 " struct sigaction sa;\n"
9364 #: build/C/man2/timer_create.2:355
9367 " if (argc != 3) {\n"
9368 " fprintf(stderr, \"Usage: %s E<lt>sleep-secsE<gt> "
9369 "E<lt>freq-nanosecsE<gt>\\en\",\n"
9371 " exit(EXIT_FAILURE);\n"
9376 #: build/C/man2/timer_create.2:357
9378 msgid " /* Establish handler for timer signal */\n"
9382 #: build/C/man2/timer_create.2:364
9385 " printf(\"Establishing handler for signal %d\\en\", SIG);\n"
9386 " sa.sa_flags = SA_SIGINFO;\n"
9387 " sa.sa_sigaction = handler;\n"
9388 " sigemptyset(&sa.sa_mask);\n"
9389 " if (sigaction(SIG, &sa, NULL) == -1)\n"
9390 " errExit(\"sigaction\");\n"
9394 #: build/C/man2/timer_create.2:366
9396 msgid " /* Block timer signal temporarily */\n"
9400 #: build/C/man2/timer_create.2:372
9403 " printf(\"Blocking signal %d\\en\", SIG);\n"
9404 " sigemptyset(&mask);\n"
9405 " sigaddset(&mask, SIG);\n"
9406 " if (sigprocmask(SIG_SETMASK, &mask, NULL) == -1)\n"
9407 " errExit(\"sigprocmask\");\n"
9411 #: build/C/man2/timer_create.2:374
9413 msgid " /* Create the timer */\n"
9417 #: build/C/man2/timer_create.2:380
9420 " sev.sigev_notify = SIGEV_SIGNAL;\n"
9421 " sev.sigev_signo = SIG;\n"
9422 " sev.sigev_value.sival_ptr = &timerid;\n"
9423 " if (timer_create(CLOCKID, &sev, &timerid) == -1)\n"
9424 " errExit(\"timer_create\");\n"
9428 #: build/C/man2/timer_create.2:382
9430 msgid " printf(\"timer ID is 0x%lx\\en\", (long) timerid);\n"
9434 #: build/C/man2/timer_create.2:384
9436 msgid " /* Start the timer */\n"
9440 #: build/C/man2/timer_create.2:390
9443 " freq_nanosecs = atoll(argv[2]);\n"
9444 " its.it_value.tv_sec = freq_nanosecs / 1000000000;\n"
9445 " its.it_value.tv_nsec = freq_nanosecs % 1000000000;\n"
9446 " its.it_interval.tv_sec = its.it_value.tv_sec;\n"
9447 " its.it_interval.tv_nsec = its.it_value.tv_nsec;\n"
9451 #: build/C/man2/timer_create.2:393
9454 " if (timer_settime(timerid, 0, &its, NULL) == -1)\n"
9455 " errExit(\"timer_settime\");\n"
9459 #: build/C/man2/timer_create.2:396
9462 " /* Sleep for a while; meanwhile, the timer may expire\n"
9463 " multiple times */\n"
9467 #: build/C/man2/timer_create.2:399
9470 " printf(\"Sleeping for %d seconds\\en\", atoi(argv[1]));\n"
9471 " sleep(atoi(argv[1]));\n"
9475 #: build/C/man2/timer_create.2:402
9478 " /* Unlock the timer signal, so that timer notification\n"
9479 " can be delivered */\n"
9483 #: build/C/man2/timer_create.2:406
9486 " printf(\"Unblocking signal %d\\en\", SIG);\n"
9487 " if (sigprocmask(SIG_UNBLOCK, &mask, NULL) == -1)\n"
9488 " errExit(\"sigprocmask\");\n"
9492 #: build/C/man2/timer_create.2:409 build/C/man2/timerfd_create.2:547
9495 " exit(EXIT_SUCCESS);\n"
9500 #: build/C/man2/timer_create.2:425
9502 "B<clock_gettime>(2), B<setitimer>(2), B<timer_delete>(2), "
9503 "B<timer_getoverrun>(2), B<timer_settime>(2), B<timerfd_create>(2), "
9504 "B<clock_getcpuclockid>(3), B<pthread_getcpuclockid>(3), B<pthreads>(7), "
9505 "B<sigevent>(7), B<signal>(7), B<time>(7)"
9509 #: build/C/man2/timer_delete.2:26
9511 msgid "TIMER_DELETE"
9515 #: build/C/man2/timer_delete.2:26 build/C/man2/timer_getoverrun.2:26
9521 #: build/C/man2/timer_delete.2:29
9522 msgid "timer_delete - delete a POSIX per-process timer"
9526 #: build/C/man2/timer_delete.2:32 build/C/man2/timer_getoverrun.2:32 build/C/man2/timer_settime.2:33
9528 msgid "B<#include E<lt>time.hE<gt>>\n"
9532 #: build/C/man2/timer_delete.2:34
9534 msgid "B<int timer_delete(timer_t >I<timerid>B<);>\n"
9538 #: build/C/man2/timer_delete.2:45
9539 msgid "B<timer_delete>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
9543 #: build/C/man2/timer_delete.2:53
9545 "B<timer_delete>() deletes the timer whose ID is given in I<timerid>. If "
9546 "the timer was armed at the time of this call, it is disarmed before being "
9547 "deleted. The treatment of any pending signal generated by the deleted timer "
9552 #: build/C/man2/timer_delete.2:60
9554 "On success, B<timer_delete>() returns 0. On failure, -1 is returned, and "
9555 "I<errno> is set to indicate the error."
9559 #: build/C/man2/timer_delete.2:65 build/C/man2/timer_getoverrun.2:95
9560 msgid "I<timerid> is not a valid timer ID."
9564 #: build/C/man2/timer_delete.2:75
9566 "B<clock_gettime>(2), B<timer_create>(2), B<timer_getoverrun>(2), "
9567 "B<timer_settime>(2), B<time>(7)"
9571 #: build/C/man2/timer_getoverrun.2:26
9573 msgid "TIMER_GETOVERRUN"
9577 #: build/C/man2/timer_getoverrun.2:29
9578 msgid "timer_getoverrun - get overrun count for a POSIX per-process timer"
9582 #: build/C/man2/timer_getoverrun.2:34
9584 msgid "B<int timer_getoverrun(timer_t >I<timerid>B<);>\n"
9588 #: build/C/man2/timer_getoverrun.2:45
9589 msgid "B<timer_getoverrun>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
9593 #: build/C/man2/timer_getoverrun.2:56
9595 "B<timer_getoverrun>() returns the \"overrun count\" for the timer referred "
9596 "to by I<timerid>. An application can use the overrun count to accurately "
9597 "calculate the number of timer expirations that would have occurred over a "
9598 "given time interval. Timer overruns can occur both when receiving "
9599 "expiration notifications via signals (B<SIGEV_SIGNAL>), and via threads "
9600 "(B<SIGEV_THREAD>)."
9604 #: build/C/man2/timer_getoverrun.2:76
9606 "When expiration notifications are delivered via a signal, overruns can occur "
9607 "as follows. Regardless of whether or not a real-time signal is used for "
9608 "timer notifications, the system queues at most one signal per timer. (This "
9609 "is the behavior specified by POSIX.1-2001. The alternative, queuing one "
9610 "signal for each timer expiration, could easily result in overflowing the "
9611 "allowed limits for queued signals on the system.) Because of system "
9612 "scheduling delays, or because the signal may be temporarily blocked, there "
9613 "can be a delay between the time when the notification signal is generated "
9614 "and the time when it is delivered (e.g., caught by a signal handler) or "
9615 "accepted (e.g., using B<sigwaitinfo>(2)). In this interval, further timer "
9616 "expirations may occur. The timer overrun count is the number of additional "
9617 "timer expirations that occurred between the time when the signal was "
9618 "generated and when it was delivered or accepted."
9622 #: build/C/man2/timer_getoverrun.2:82
9624 "Timer overruns can also occur when expiration notifications are delivered "
9625 "via invocation of a thread, since there may be an arbitrary delay between an "
9626 "expiration of the timer and the invocation of the notification thread, and "
9627 "in that delay interval, additional timer expirations may occur."
9631 #: build/C/man2/timer_getoverrun.2:90
9633 "On success, B<timer_getoverrun>() returns the overrun count of the "
9634 "specified timer; this count may be 0 if no overruns have occurred. On "
9635 "failure, -1 is returned, and I<errno> is set to indicate the error."
9639 #: build/C/man2/timer_getoverrun.2:111
9641 "When timer notifications are delivered via signals (B<SIGEV_SIGNAL>), on "
9642 "Linux it is also possible to obtain the overrun count via the I<si_overrun> "
9643 "field of the I<siginfo_t> structure (see B<sigaction>(2)). This allows an "
9644 "application to avoid the overhead of making a system call to obtain the "
9645 "overrun count, but is a nonportable extension to POSIX.1-2001."
9648 #. FIXME . Austin bug filed, 11 Feb 09
9650 #: build/C/man2/timer_getoverrun.2:115
9652 "POSIX.1-2001 discusses timer overruns only in the context of timer "
9653 "notifications using signals."
9656 #. Bug filed: http://bugzilla.kernel.org/show_bug.cgi?id=12665
9657 #. http://thread.gmane.org/gmane.linux.kernel/113276/
9659 #: build/C/man2/timer_getoverrun.2:128
9661 "POSIX.1-2001 specifies that if the timer overrun count is equal to or "
9662 "greater than an implementation-defined maximum, B<DELAYTIMER_MAX>, then "
9663 "B<timer_getoverrun>() should return B<DELAYTIMER_MAX>. However, Linux does "
9664 "not implement this feature: instead, if the timer overrun value exceeds the "
9665 "maximum representable integer, the counter cycles, starting once more from "
9670 #: build/C/man2/timer_getoverrun.2:131 build/C/man2/timer_settime.2:212
9671 msgid "See B<timer_create>(2)."
9675 #: build/C/man2/timer_getoverrun.2:141
9677 "B<clock_gettime>(2), B<sigaction>(2), B<signalfd>(2), B<sigwaitinfo>(2), "
9678 "B<timer_create>(2), B<timer_delete>(2), B<timer_settime>(2), B<signal>(7), "
9683 #: build/C/man2/timer_settime.2:26
9685 msgid "TIMER_SETTIME"
9689 #: build/C/man2/timer_settime.2:26
9695 #: build/C/man2/timer_settime.2:30
9697 "timer_settime, timer_gettime - arm/disarm and fetch state of POSIX "
9702 #: build/C/man2/timer_settime.2:38
9705 "B<int timer_settime(timer_t >I<timerid>B<, int >I<flags>B<,>\n"
9706 "B< const struct itimerspec *>I<new_value>B<,>\n"
9707 "B< struct itimerspec *>I<old_value>B<);>\n"
9708 "B<int timer_gettime(timer_t >I<timerid>B<, struct itimerspec "
9709 "*>I<curr_value>B<);>\n"
9713 #: build/C/man2/timer_settime.2:50
9714 msgid "B<timer_settime>(), B<timer_gettime>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
9718 #: build/C/man2/timer_settime.2:63
9720 "B<timer_settime>() arms or disarms the timer identified by I<timerid>. The "
9721 "I<new_value> argument is pointer to an I<itimerspec> structure that "
9722 "specifies the new initial value and the new interval for the timer. The "
9723 "I<itimerspec> structure is defined as follows:"
9727 #: build/C/man2/timer_settime.2:70 build/C/man2/timerfd_create.2:135
9730 "struct timespec {\n"
9731 " time_t tv_sec; /* Seconds */\n"
9732 " long tv_nsec; /* Nanoseconds */\n"
9737 #: build/C/man2/timer_settime.2:75
9740 "struct itimerspec {\n"
9741 " struct timespec it_interval; /* Timer interval */\n"
9742 " struct timespec it_value; /* Initial expiration */\n"
9747 #: build/C/man2/timer_settime.2:87
9749 "Each of the substructures of the I<itimerspec> structure is a I<timespec> "
9750 "structure that allows a time value to be specified in seconds and "
9751 "nanoseconds. These time values are measured according to the clock that was "
9752 "specified when the timer was created by B<timer_create>(2)."
9756 #: build/C/man2/timer_settime.2:101
9758 "If I<new_value-E<gt>it_value> specifies a nonzero value (i.e., either "
9759 "subfield is nonzero), then B<timer_settime>() arms (starts) the timer, "
9760 "setting it to initially expire at the given time. (If the timer was already "
9761 "armed, then the previous settings are overwritten.) If "
9762 "I<new_value-E<gt>it_value> specifies a zero value (i.e., both subfields are "
9763 "zero), then the timer is disarmed."
9767 #: build/C/man2/timer_settime.2:113
9769 "The I<new_value-E<gt>it_interval> field specifies the period of the timer, "
9770 "in seconds and nanoseconds. If this field is nonzero, then each time that "
9771 "an armed timer expires, the timer is reloaded from the value specified in "
9772 "I<new_value-E<gt>it_interval>. If I<new_value-E<gt>it_interval> specifies a "
9773 "zero value, then the timer expires just once, at the time specified by "
9777 #. By experiment: the overrun count is set correctly, for CLOCK_REALTIME.
9779 #: build/C/man2/timer_settime.2:134
9781 "By default, the initial expiration time specified in "
9782 "I<new_value-E<gt>it_value> is interpreted relative to the current time on "
9783 "the timer's clock at the time of the call. This can be modified by "
9784 "specifying B<TIMER_ABSTIME> in I<flags>, in which case "
9785 "I<new_value-E<gt>it_value> is interpreted as an absolute value as measured "
9786 "on the timer's clock; that is, the timer will expire when the clock value "
9787 "reaches the value specified by I<new_value-E<gt>it_value>. If the specified "
9788 "absolute time has already passed, then the timer expires immediately, and "
9789 "the overrun count (see B<timer_getoverrun>(2)) will be set correctly."
9792 #. Similar remarks might apply with respect to process and thread CPU time
9793 #. clocks, but these clocks are not currently (2.6.28) settable on Linux.
9795 #: build/C/man2/timer_settime.2:144
9797 "If the value of the B<CLOCK_REALTIME> clock is adjusted while an absolute "
9798 "timer based on that clock is armed, then the expiration of the timer will be "
9799 "appropriately adjusted. Adjustments to the B<CLOCK_REALTIME> clock have no "
9800 "effect on relative timers based on that clock."
9804 #: build/C/man2/timer_settime.2:153
9806 "If I<old_value> is not NULL, then it points to a buffer that is used to "
9807 "return the previous interval of the timer (in I<old_value-E<gt>it_interval>) "
9808 "and the amount of time until the timer would previously have next expired "
9809 "(in I<old_value-E<gt>it_value>)."
9813 #: build/C/man2/timer_settime.2:173
9815 "B<timer_gettime>() returns the time until next expiration, and the "
9816 "interval, for the timer specified by I<timerid>, in the buffer pointed to by "
9817 "I<curr_value>. The time remaining until the next timer expiration is "
9818 "returned in I<curr_value-E<gt>it_value>; this is always a relative value, "
9819 "regardless of whether the B<TIMER_ABSTIME> flag was used when arming the "
9820 "timer. If the value returned in I<curr_value-E<gt>it_value> is zero, then "
9821 "the timer is currently disarmed. The timer interval is returned in "
9822 "I<curr_value-E<gt>it_interval>. If the value returned in "
9823 "I<curr_value-E<gt>it_interval> is zero, then this is a \"one-shot\" timer."
9827 #: build/C/man2/timer_settime.2:182
9829 "On success, B<timer_settime>() and B<timer_gettime>() return 0. On error, "
9830 "-1 is returned, and I<errno> is set to indicate the error."
9834 #: build/C/man2/timer_settime.2:184
9835 msgid "These functions may fail with the following errors:"
9839 #: build/C/man2/timer_settime.2:191
9840 msgid "I<new_value>, I<old_value>, or I<curr_value> is not a valid pointer."
9843 #. FIXME . eventually: invalid value in flags
9845 #: build/C/man2/timer_settime.2:196
9846 msgid "I<timerid> is invalid."
9850 #: build/C/man2/timer_settime.2:199
9851 msgid "B<timer_settime>() may fail with the following errors:"
9855 #: build/C/man2/timer_settime.2:205
9857 "I<new_value.it_value> is negative; or I<new_value.it_value.tv_nsec> is "
9858 "negative or greater than 999,999,999."
9862 #: build/C/man2/timer_settime.2:207
9863 msgid "These system calls are available since Linux 2.6."
9867 #: build/C/man2/timer_settime.2:216
9868 msgid "B<timer_create>(2), B<timer_getoverrun>(2), B<time>(7)"
9872 #: build/C/man2/timerfd_create.2:22
9874 msgid "TIMERFD_CREATE"
9878 #: build/C/man2/timerfd_create.2:22
9884 #: build/C/man2/timerfd_create.2:26
9886 "timerfd_create, timerfd_settime, timerfd_gettime - timers that notify via "
9891 #: build/C/man2/timerfd_create.2:29
9893 msgid "B<#include E<lt>sys/timerfd.hE<gt>>\n"
9897 #: build/C/man2/timerfd_create.2:31
9899 msgid "B<int timerfd_create(int >I<clockid>B<, int >I<flags>B<);>\n"
9903 #: build/C/man2/timerfd_create.2:35
9906 "B<int timerfd_settime(int >I<fd>B<, int >I<flags>B<,>\n"
9907 "B< const struct itimerspec *>I<new_value>B<,>\n"
9908 "B< struct itimerspec *>I<old_value>B<);>\n"
9912 #: build/C/man2/timerfd_create.2:37
9914 msgid "B<int timerfd_gettime(int >I<fd>B<, struct itimerspec *>I<curr_value>B<);>\n"
9918 #: build/C/man2/timerfd_create.2:50
9920 "These system calls create and operate on a timer that delivers timer "
9921 "expiration notifications via a file descriptor. They provide an alternative "
9922 "to the use of B<setitimer>(2) or B<timer_create>(2), with the advantage "
9923 "that the file descriptor may be monitored by B<select>(2), B<poll>(2), and "
9928 #: build/C/man2/timerfd_create.2:62
9930 "The use of these three system calls is analogous to the use of "
9931 "B<timer_create>(2), B<timer_settime>(2), and B<timer_gettime>(2). (There is "
9932 "no analog of B<timer_getoverrun>(2), since that functionality is provided by "
9933 "B<read>(2), as described below.)"
9937 #: build/C/man2/timerfd_create.2:62
9939 msgid "timerfd_create()"
9943 #. Additional clocks are now supported:
9944 #. CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM
9945 #. Since Linux 3.11, commit 11ffa9d6065f344a9bd769a2452f26f2f671e5f8
9947 #. Since Linux 3.15, commit 4a2378a943f09907fb1ae35c15de917f60289c14
9949 #: build/C/man2/timerfd_create.2:87
9951 "B<timerfd_create>() creates a new timer object, and returns a file "
9952 "descriptor that refers to that timer. The I<clockid> argument specifies the "
9953 "clock that is used to mark the progress of the timer, and must be either "
9954 "B<CLOCK_REALTIME> or B<CLOCK_MONOTONIC>. B<CLOCK_REALTIME> is a settable "
9955 "system-wide clock. B<CLOCK_MONOTONIC> is a nonsettable clock that is not "
9956 "affected by discontinuous changes in the system clock (e.g., manual changes "
9957 "to system time). The current value of each of these clocks can be retrieved "
9958 "using B<clock_gettime>(2)."
9962 #: build/C/man2/timerfd_create.2:92
9964 "Starting with Linux 2.6.27, the following values may be bitwise ORed in "
9965 "I<flags> to change the behavior of B<timerfd_create>():"
9969 #: build/C/man2/timerfd_create.2:92
9971 msgid "B<TFD_NONBLOCK>"
9975 #: build/C/man2/timerfd_create.2:100
9977 msgid "B<TFD_CLOEXEC>"
9981 #: build/C/man2/timerfd_create.2:114
9983 "In Linux versions up to and including 2.6.26, I<flags> must be specified as "
9988 #: build/C/man2/timerfd_create.2:114
9990 msgid "timerfd_settime()"
9994 #: build/C/man2/timerfd_create.2:119
9996 "B<timerfd_settime>() arms (starts) or disarms (stops) the timer referred "
9997 "to by the file descriptor I<fd>."
10000 #. type: Plain text
10001 #: build/C/man2/timerfd_create.2:128
10003 "The I<new_value> argument specifies the initial expiration and interval for "
10004 "the timer. The I<itimer> structure used for this argument contains two "
10005 "fields, each of which is in turn a structure of type I<timespec>:"
10008 #. type: Plain text
10009 #: build/C/man2/timerfd_create.2:140
10012 "struct itimerspec {\n"
10013 " struct timespec it_interval; /* Interval for periodic timer */\n"
10014 " struct timespec it_value; /* Initial expiration */\n"
10018 #. type: Plain text
10019 #: build/C/man2/timerfd_create.2:152
10021 "I<new_value.it_value> specifies the initial expiration of the timer, in "
10022 "seconds and nanoseconds. Setting either field of I<new_value.it_value> to a "
10023 "nonzero value arms the timer. Setting both fields of I<new_value.it_value> "
10024 "to zero disarms the timer."
10027 #. type: Plain text
10028 #: build/C/man2/timerfd_create.2:161
10030 "Setting one or both fields of I<new_value.it_interval> to nonzero values "
10031 "specifies the period, in seconds and nanoseconds, for repeated timer "
10032 "expirations after the initial expiration. If both fields of "
10033 "I<new_value.it_interval> are zero, the timer expires just once, at the time "
10034 "specified by I<new_value.it_value>."
10037 #. type: Plain text
10038 #: build/C/man2/timerfd_create.2:177
10040 "The I<flags> argument is either 0, to start a relative timer "
10041 "(I<new_value.it_value> specifies a time relative to the current value of the "
10042 "clock specified by I<clockid>), or B<TFD_TIMER_ABSTIME>, to start an "
10043 "absolute timer (I<new_value.it_value> specifies an absolute time for the "
10044 "clock specified by I<clockid>; that is, the timer will expire when the value "
10045 "of that clock reaches the value specified in I<new_value.it_value>)."
10048 #. type: Plain text
10049 #: build/C/man2/timerfd_create.2:188
10051 "If the I<old_value> argument is not NULL, then the I<itimerspec> structure "
10052 "that it points to is used to return the setting of the timer that was "
10053 "current at the time of the call; see the description of B<timerfd_gettime>() "
10058 #: build/C/man2/timerfd_create.2:188
10060 msgid "timerfd_gettime()"
10063 #. type: Plain text
10064 #: build/C/man2/timerfd_create.2:197
10066 "B<timerfd_gettime>() returns, in I<curr_value>, an I<itimerspec> structure "
10067 "that contains the current setting of the timer referred to by the file "
10068 "descriptor I<fd>."
10071 #. type: Plain text
10072 #: build/C/man2/timerfd_create.2:207
10074 "The I<it_value> field returns the amount of time until the timer will next "
10075 "expire. If both fields of this structure are zero, then the timer is "
10076 "currently disarmed. This field always contains a relative value, regardless "
10077 "of whether the B<TFD_TIMER_ABSTIME> flag was specified when setting the "
10081 #. type: Plain text
10082 #: build/C/man2/timerfd_create.2:214
10084 "The I<it_interval> field returns the interval of the timer. If both fields "
10085 "of this structure are zero, then the timer is set to expire just once, at "
10086 "the time specified by I<curr_value.it_value>."
10090 #: build/C/man2/timerfd_create.2:214
10092 msgid "Operating on a timer file descriptor"
10095 #. type: Plain text
10096 #: build/C/man2/timerfd_create.2:218
10098 "The file descriptor returned by B<timerfd_create>() supports the following "
10102 #. type: Plain text
10103 #: build/C/man2/timerfd_create.2:232
10105 "If the timer has already expired one or more times since its settings were "
10106 "last modified using B<timerfd_settime>(), or since the last successful "
10107 "B<read>(2), then the buffer given to B<read>(2) returns an unsigned 8-byte "
10108 "integer (I<uint64_t>) containing the number of expirations that have "
10109 "occurred. (The returned value is in host byte order\\(emthat is, the native "
10110 "byte order for integers on the host machine.)"
10113 #. type: Plain text
10114 #: build/C/man2/timerfd_create.2:245
10116 "If no timer expirations have occurred at the time of the B<read>(2), then "
10117 "the call either blocks until the next timer expiration, or fails with the "
10118 "error B<EAGAIN> if the file descriptor has been made nonblocking (via the "
10119 "use of the B<fcntl>(2) B<F_SETFL> operation to set the B<O_NONBLOCK> flag)."
10122 #. type: Plain text
10123 #: build/C/man2/timerfd_create.2:251
10125 "A B<read>(2) will fail with the error B<EINVAL> if the size of the supplied "
10126 "buffer is less than 8 bytes."
10129 #. type: Plain text
10130 #: build/C/man2/timerfd_create.2:262
10132 "The file descriptor is readable (the B<select>(2) I<readfds> argument; the "
10133 "B<poll>(2) B<POLLIN> flag) if one or more timer expirations have occurred."
10136 #. type: Plain text
10137 #: build/C/man2/timerfd_create.2:269
10139 "The file descriptor also supports the other file-descriptor multiplexing "
10140 "APIs: B<pselect>(2), B<ppoll>(2), and B<epoll>(7)."
10143 #. type: Plain text
10144 #: build/C/man2/timerfd_create.2:276
10146 "When the file descriptor is no longer required it should be closed. When "
10147 "all file descriptors associated with the same timer object have been closed, "
10148 "the timer is disarmed and its resources are freed by the kernel."
10151 #. type: Plain text
10152 #: build/C/man2/timerfd_create.2:288
10154 "After a B<fork>(2), the child inherits a copy of the file descriptor created "
10155 "by B<timerfd_create>(). The file descriptor refers to the same underlying "
10156 "timer object as the corresponding file descriptor in the parent, and "
10157 "B<read>(2)s in the child will return information about expirations of the "
10161 #. type: Plain text
10162 #: build/C/man2/timerfd_create.2:294
10164 "A file descriptor created by B<timerfd_create>() is preserved across "
10165 "B<execve>(2), and continues to generate timer expirations if the timer was "
10169 #. type: Plain text
10170 #: build/C/man2/timerfd_create.2:301
10172 "On success, B<timerfd_create>() returns a new file descriptor. On error, "
10173 "-1 is returned and I<errno> is set to indicate the error."
10176 #. type: Plain text
10177 #: build/C/man2/timerfd_create.2:309
10179 "B<timerfd_settime>() and B<timerfd_gettime>() return 0 on success; on "
10180 "error they return -1, and set I<errno> to indicate the error."
10183 #. type: Plain text
10184 #: build/C/man2/timerfd_create.2:312
10185 msgid "B<timerfd_create>() can fail with the following errors:"
10188 #. type: Plain text
10189 #: build/C/man2/timerfd_create.2:320
10190 msgid "The I<clockid> argument is neither B<CLOCK_MONOTONIC> nor B<CLOCK_REALTIME>;"
10193 #. type: Plain text
10194 #: build/C/man2/timerfd_create.2:340
10195 msgid "There was insufficient kernel memory to create the timer."
10198 #. type: Plain text
10199 #: build/C/man2/timerfd_create.2:345
10201 "B<timerfd_settime>() and B<timerfd_gettime>() can fail with the following "
10205 #. type: Plain text
10206 #: build/C/man2/timerfd_create.2:349
10207 msgid "I<fd> is not a valid file descriptor."
10210 #. type: Plain text
10211 #: build/C/man2/timerfd_create.2:360
10212 msgid "I<fd> is not a valid timerfd file descriptor."
10215 #. type: Plain text
10216 #: build/C/man2/timerfd_create.2:363
10217 msgid "B<timerfd_settime>() can also fail with the following errors:"
10220 #. type: Plain text
10221 #: build/C/man2/timerfd_create.2:369
10223 "I<new_value> is not properly initialized (one of the I<tv_nsec> falls "
10224 "outside the range zero to 999,999,999)."
10227 #. This case only checked since 2.6.29, and 2.2.2[78].some-stable-version.
10228 #. In older kernel versions, no check was made for invalid flags.
10229 #. type: Plain text
10230 #: build/C/man2/timerfd_create.2:375
10231 msgid "I<flags> is invalid."
10234 #. type: Plain text
10235 #: build/C/man2/timerfd_create.2:378
10237 "These system calls are available on Linux since kernel 2.6.25. Library "
10238 "support is provided by glibc since version 2.8."
10242 #. type: Plain text
10243 #: build/C/man2/timerfd_create.2:386
10245 "Currently, B<timerfd_create>() supports fewer types of clock IDs than "
10246 "B<timer_create>(2)."
10249 #. type: Plain text
10250 #: build/C/man2/timerfd_create.2:395
10252 "The following program creates a timer and then monitors its progress. The "
10253 "program accepts up to three command-line arguments. The first argument "
10254 "specifies the number of seconds for the initial expiration of the timer. "
10255 "The second argument specifies the interval for the timer, in seconds. The "
10256 "third argument specifies the number of times the program should allow the "
10257 "timer to expire before terminating. The second and third command-line "
10258 "arguments are optional."
10261 #. type: Plain text
10262 #: build/C/man2/timerfd_create.2:397 build/C/man2/wait.2:571
10263 msgid "The following shell session demonstrates the use of the program:"
10266 #. type: Plain text
10267 #: build/C/man2/timerfd_create.2:412
10270 "$B< a.out 3 1 100>\n"
10271 "0.000: timer started\n"
10272 "3.000: read: 1; total=1\n"
10273 "4.000: read: 1; total=2\n"
10274 "B<^Z > # type control-Z to suspend the program\n"
10275 "[1]+ Stopped ./timerfd3_demo 3 1 100\n"
10276 "$ B<fg> # Resume execution after a few seconds\n"
10278 "9.660: read: 5; total=7\n"
10279 "10.000: read: 1; total=8\n"
10280 "11.000: read: 1; total=9\n"
10281 "B<^C > # type control-C to suspend the program\n"
10284 #. The commented out code here is what we currently need until
10285 #. the required stuff is in glibc
10288 #. /* Link with -lrt */
10289 #. #define _GNU_SOURCE
10290 #. #include <sys/syscall.h>
10291 #. #include <unistd.h>
10292 #. #include <time.h>
10293 #. #if defined(__i386__)
10294 #. #define __NR_timerfd_create 322
10295 #. #define __NR_timerfd_settime 325
10296 #. #define __NR_timerfd_gettime 326
10300 #. timerfd_create(int clockid, int flags)
10302 #. return syscall(__NR_timerfd_create, clockid, flags);
10306 #. timerfd_settime(int fd, int flags, struct itimerspec *new_value,
10307 #. struct itimerspec *curr_value)
10309 #. return syscall(__NR_timerfd_settime, fd, flags, new_value,
10314 #. timerfd_gettime(int fd, struct itimerspec *curr_value)
10316 #. return syscall(__NR_timerfd_gettime, fd, curr_value);
10319 #. #define TFD_TIMER_ABSTIME (1 << 0)
10321 #. ////////////////////////////////////////////////////////////
10322 #. type: Plain text
10323 #: build/C/man2/timerfd_create.2:461
10326 "#include E<lt>sys/timerfd.hE<gt>\n"
10327 "#include E<lt>time.hE<gt>\n"
10328 "#include E<lt>unistd.hE<gt>\n"
10329 "#include E<lt>stdlib.hE<gt>\n"
10330 "#include E<lt>stdio.hE<gt>\n"
10331 "#include E<lt>stdint.hE<gt> /* Definition of uint64_t */\n"
10334 #. type: Plain text
10335 #: build/C/man2/timerfd_create.2:464
10338 "#define handle_error(msg) \\e\n"
10339 " do { perror(msg); exit(EXIT_FAILURE); } while (0)\n"
10342 #. type: Plain text
10343 #: build/C/man2/timerfd_create.2:472
10347 "print_elapsed_time(void)\n"
10349 " static struct timespec start;\n"
10350 " struct timespec curr;\n"
10351 " static int first_call = 1;\n"
10352 " int secs, nsecs;\n"
10355 #. type: Plain text
10356 #: build/C/man2/timerfd_create.2:478
10359 " if (first_call) {\n"
10360 " first_call = 0;\n"
10361 " if (clock_gettime(CLOCK_MONOTONIC, &start) == -1)\n"
10362 " handle_error(\"clock_gettime\");\n"
10366 #. type: Plain text
10367 #: build/C/man2/timerfd_create.2:481
10370 " if (clock_gettime(CLOCK_MONOTONIC, &curr) == -1)\n"
10371 " handle_error(\"clock_gettime\");\n"
10374 #. type: Plain text
10375 #: build/C/man2/timerfd_create.2:490
10378 " secs = curr.tv_sec - start.tv_sec;\n"
10379 " nsecs = curr.tv_nsec - start.tv_nsec;\n"
10380 " if (nsecs E<lt> 0) {\n"
10382 " nsecs += 1000000000;\n"
10384 " printf(\"%d.%03d: \", secs, (nsecs + 500000) / 1000000);\n"
10388 #. type: Plain text
10389 #: build/C/man2/timerfd_create.2:499
10393 "main(int argc, char *argv[])\n"
10395 " struct itimerspec new_value;\n"
10396 " int max_exp, fd;\n"
10397 " struct timespec now;\n"
10398 " uint64_t exp, tot_exp;\n"
10402 #. type: Plain text
10403 #: build/C/man2/timerfd_create.2:505
10406 " if ((argc != 2) && (argc != 4)) {\n"
10407 " fprintf(stderr, \"%s init-secs [interval-secs max-exp]\\en\",\n"
10409 " exit(EXIT_FAILURE);\n"
10413 #. type: Plain text
10414 #: build/C/man2/timerfd_create.2:508
10417 " if (clock_gettime(CLOCK_REALTIME, &now) == -1)\n"
10418 " handle_error(\"clock_gettime\");\n"
10421 #. type: Plain text
10422 #: build/C/man2/timerfd_create.2:511
10425 " /* Create a CLOCK_REALTIME absolute timer with initial\n"
10426 " expiration and interval as specified in command line */\n"
10429 #. type: Plain text
10430 #: build/C/man2/timerfd_create.2:522
10433 " new_value.it_value.tv_sec = now.tv_sec + atoi(argv[1]);\n"
10434 " new_value.it_value.tv_nsec = now.tv_nsec;\n"
10435 " if (argc == 2) {\n"
10436 " new_value.it_interval.tv_sec = 0;\n"
10439 " new_value.it_interval.tv_sec = atoi(argv[2]);\n"
10440 " max_exp = atoi(argv[3]);\n"
10442 " new_value.it_interval.tv_nsec = 0;\n"
10445 #. type: Plain text
10446 #: build/C/man2/timerfd_create.2:526
10449 " fd = timerfd_create(CLOCK_REALTIME, 0);\n"
10451 " handle_error(\"timerfd_create\");\n"
10454 #. type: Plain text
10455 #: build/C/man2/timerfd_create.2:529
10458 " if (timerfd_settime(fd, TFD_TIMER_ABSTIME, &new_value, NULL) == -1)\n"
10459 " handle_error(\"timerfd_settime\");\n"
10462 #. type: Plain text
10463 #: build/C/man2/timerfd_create.2:532
10466 " print_elapsed_time();\n"
10467 " printf(\"timer started\\en\");\n"
10470 #. type: Plain text
10471 #: build/C/man2/timerfd_create.2:537
10474 " for (tot_exp = 0; tot_exp E<lt> max_exp;) {\n"
10475 " s = read(fd, &exp, sizeof(uint64_t));\n"
10476 " if (s != sizeof(uint64_t))\n"
10477 " handle_error(\"read\");\n"
10480 #. type: Plain text
10481 #: build/C/man2/timerfd_create.2:544
10484 " tot_exp += exp;\n"
10485 " print_elapsed_time();\n"
10486 " printf(\"read: %llu; total=%llu\\en\",\n"
10487 " (unsigned long long) exp,\n"
10488 " (unsigned long long) tot_exp);\n"
10492 #. type: Plain text
10493 #: build/C/man2/timerfd_create.2:560
10495 "B<eventfd>(2), B<poll>(2), B<read>(2), B<select>(2), B<setitimer>(2), "
10496 "B<signalfd>(2), B<timer_create>(2), B<timer_gettime>(2), "
10497 "B<timer_settime>(2), B<epoll>(7), B<time>(7)"
10501 #: build/C/man2/tkill.2:29
10506 #. type: Plain text
10507 #: build/C/man2/tkill.2:32
10508 msgid "tkill, tgkill - send a signal to a thread"
10511 #. type: Plain text
10512 #: build/C/man2/tkill.2:35
10514 msgid "B<int tkill(int >I<tid>B<, int >I<sig>B<);>\n"
10517 #. type: Plain text
10518 #: build/C/man2/tkill.2:37
10520 msgid "B<int tgkill(int >I<tgid>B<, int >I<tid>B<, int >I<sig>B<);>\n"
10523 #. type: Plain text
10524 #: build/C/man2/tkill.2:54
10526 "B<tgkill>() sends the signal I<sig> to the thread with the thread ID I<tid> "
10527 "in the thread group I<tgid>. (By contrast, B<kill>(2) can be used to send "
10528 "a signal only to a process (i.e., thread group) as a whole, and the signal "
10529 "will be delivered to an arbitrary thread within that process.)"
10532 #. FIXME Maybe say something about the following:
10533 #. http://sourceware.org/bugzilla/show_bug.cgi?id=12889
10534 #. Rich Felker <bugdal@aerifal.cx>
10535 #. There is a race condition in pthread_kill: it is possible that,
10536 #. between the time pthread_kill reads the pid/tid from the target
10537 #. thread descriptor and the time it makes the tgkill syscall,
10538 #. the target thread terminates and the same tid gets assigned
10539 #. to a new thread in the same process.
10541 #. (The tgkill syscall was designed to eliminate a similar race
10542 #. condition in tkill, but it only succeeded in eliminating races
10543 #. where the tid gets reused in a different process, and does not
10544 #. help if the same tid gets assigned to a new thread in the
10547 #. The only solution I can see is to introduce a mutex that ensures
10548 #. that a thread cannot exit while pthread_kill is being called on it.
10550 #. Note that in most real-world situations, like almost all race
10551 #. conditions, this one will be extremely rare. To make it
10552 #. measurable, one could exhaust all but 1-2 available pid values,
10553 #. possibly by lowering the max pid parameter in /proc, forcing
10554 #. the same tid to be reused rapidly.
10555 #. type: Plain text
10556 #: build/C/man2/tkill.2:85
10558 "B<tkill>() is an obsolete predecessor to B<tgkill>(). It allows only the "
10559 "target thread ID to be specified, which may result in the wrong thread being "
10560 "signaled if a thread terminates and its thread ID is recycled. Avoid using "
10561 "this system call."
10564 #. type: Plain text
10565 #: build/C/man2/tkill.2:88
10567 "These are the raw system call interfaces, meant for internal thread library "
10571 #. type: Plain text
10572 #: build/C/man2/tkill.2:96
10573 msgid "An invalid thread ID, thread group ID, or signal was specified."
10576 #. type: Plain text
10577 #: build/C/man2/tkill.2:101
10578 msgid "Permission denied. For the required permissions, see B<kill>(2)."
10581 #. type: Plain text
10582 #: build/C/man2/tkill.2:104
10583 msgid "No process with the specified thread ID (and thread group ID) exists."
10586 #. type: Plain text
10587 #: build/C/man2/tkill.2:109
10589 "B<tkill>() is supported since Linux 2.4.19 / 2.5.4. B<tgkill>() was added "
10593 #. type: Plain text
10594 #: build/C/man2/tkill.2:115
10596 "B<tkill>() and B<tgkill>() are Linux-specific and should not be used in "
10597 "programs that are intended to be portable."
10600 #. type: Plain text
10601 #: build/C/man2/tkill.2:121
10603 "See the description of B<CLONE_THREAD> in B<clone>(2) for an explanation of "
10607 #. type: Plain text
10608 #: build/C/man2/tkill.2:124
10610 "Glibc does not provide wrappers for these system calls; call them using "
10614 #. type: Plain text
10615 #: build/C/man2/tkill.2:129
10616 msgid "B<clone>(2), B<gettid>(2), B<kill>(2), B<rt_sigqueueinfo>(2)"
10620 #: build/C/man2/wait.2:49
10625 #. type: Plain text
10626 #: build/C/man2/wait.2:52
10627 msgid "wait, waitpid, waitid - wait for process to change state"
10630 #. type: Plain text
10631 #: build/C/man2/wait.2:54
10632 msgid "B<#include E<lt>sys/types.hE<gt>>"
10635 #. type: Plain text
10636 #: build/C/man2/wait.2:56
10637 msgid "B<#include E<lt>sys/wait.hE<gt>>"
10640 #. type: Plain text
10641 #: build/C/man2/wait.2:58
10642 msgid "B<pid_t wait(int *>I<status>B<);>"
10645 #. type: Plain text
10646 #: build/C/man2/wait.2:60
10647 msgid "B<pid_t waitpid(pid_t >I<pid>B<, int *>I<status>B<, int >I<options>B<);>"
10650 #. type: Plain text
10651 #: build/C/man2/wait.2:65
10654 "B<int waitid(idtype_t >I<idtype>B<, id_t >I<id>B<, siginfo_t *>I<infop>B<, "
10655 "int >I<options>B<);>\n"
10656 " /* This is the glibc and POSIX interface; see\n"
10657 " NOTES for information on the raw system call. */\n"
10660 #. type: Plain text
10661 #: build/C/man2/wait.2:74
10662 msgid "B<waitid>():"
10665 #. type: Plain text
10666 #: build/C/man2/wait.2:78
10668 "_SVID_SOURCE || _XOPEN_SOURCE\\ E<gt>=\\ 500 || _XOPEN_SOURCE\\ &&\\ "
10669 "_XOPEN_SOURCE_EXTENDED"
10672 #. type: Plain text
10673 #: build/C/man2/wait.2:93
10675 "All of these system calls are used to wait for state changes in a child of "
10676 "the calling process, and obtain information about the child whose state has "
10677 "changed. A state change is considered to be: the child terminated; the "
10678 "child was stopped by a signal; or the child was resumed by a signal. In the "
10679 "case of a terminated child, performing a wait allows the system to release "
10680 "the resources associated with the child; if a wait is not performed, then "
10681 "the terminated child remains in a \"zombie\" state (see NOTES below)."
10684 #. type: Plain text
10685 #: build/C/man2/wait.2:105
10687 "If a child has already changed state, then these calls return immediately. "
10688 "Otherwise, they block until either a child changes state or a signal handler "
10689 "interrupts the call (assuming that system calls are not automatically "
10690 "restarted using the B<SA_RESTART> flag of B<sigaction>(2)). In the "
10691 "remainder of this page, a child whose state has changed and which has not "
10692 "yet been waited upon by one of these system calls is termed I<waitable>."
10696 #: build/C/man2/wait.2:105
10698 msgid "wait() and waitpid()"
10701 #. type: Plain text
10702 #: build/C/man2/wait.2:113
10704 "The B<wait>() system call suspends execution of the calling process until "
10705 "one of its children terminates. The call I<wait(&status)> is equivalent to:"
10708 #. type: Plain text
10709 #: build/C/man2/wait.2:116
10711 msgid " waitpid(-1, &status, 0);\n"
10714 #. type: Plain text
10715 #: build/C/man2/wait.2:130
10717 "The B<waitpid>() system call suspends execution of the calling process "
10718 "until a child specified by I<pid> argument has changed state. By default, "
10719 "B<waitpid>() waits only for terminated children, but this behavior is "
10720 "modifiable via the I<options> argument, as described below."
10723 #. type: Plain text
10724 #: build/C/man2/wait.2:134
10725 msgid "The value of I<pid> can be:"
10729 #: build/C/man2/wait.2:134
10734 #. type: Plain text
10735 #: build/C/man2/wait.2:138
10737 "meaning wait for any child process whose process group ID is equal to the "
10738 "absolute value of I<pid>."
10742 #: build/C/man2/wait.2:138
10747 #. type: Plain text
10748 #: build/C/man2/wait.2:140
10749 msgid "meaning wait for any child process."
10753 #: build/C/man2/wait.2:140
10758 #. type: Plain text
10759 #: build/C/man2/wait.2:143
10761 "meaning wait for any child process whose process group ID is equal to that "
10762 "of the calling process."
10766 #: build/C/man2/wait.2:143
10771 #. type: Plain text
10772 #: build/C/man2/wait.2:147
10773 msgid "meaning wait for the child whose process ID is equal to the value of I<pid>."
10776 #. type: Plain text
10777 #: build/C/man2/wait.2:151
10778 msgid "The value of I<options> is an OR of zero or more of the following constants:"
10782 #: build/C/man2/wait.2:151 build/C/man2/wait.2:280
10787 #. type: Plain text
10788 #: build/C/man2/wait.2:154
10789 msgid "return immediately if no child has exited."
10793 #: build/C/man2/wait.2:154
10795 msgid "B<WUNTRACED>"
10798 #. type: Plain text
10799 #: build/C/man2/wait.2:163
10801 "also return if a child has stopped (but not traced via B<ptrace>(2)). "
10802 "Status for I<traced> children which have stopped is provided even if this "
10803 "option is not specified."
10807 #: build/C/man2/wait.2:163
10809 msgid "B<WCONTINUED> (since Linux 2.6.10)"
10812 #. type: Plain text
10813 #: build/C/man2/wait.2:167
10814 msgid "also return if a stopped child has been resumed by delivery of B<SIGCONT>."
10817 #. type: Plain text
10818 #: build/C/man2/wait.2:169
10819 msgid "(For Linux-only options, see below.)"
10822 #. type: Plain text
10823 #: build/C/man2/wait.2:183
10825 "If I<status> is not NULL, B<wait>() and B<waitpid>() store status "
10826 "information in the I<int> to which it points. This integer can be inspected "
10827 "with the following macros (which take the integer itself as an argument, not "
10828 "a pointer to it, as is done in B<wait>() and B<waitpid>()!):"
10832 #: build/C/man2/wait.2:183
10834 msgid "B<WIFEXITED(>I<status>B<)>"
10837 #. type: Plain text
10838 #: build/C/man2/wait.2:191
10840 "returns true if the child terminated normally, that is, by calling "
10841 "B<exit>(3) or B<_exit>(2), or by returning from main()."
10845 #: build/C/man2/wait.2:191
10847 msgid "B<WEXITSTATUS(>I<status>B<)>"
10850 #. type: Plain text
10851 #: build/C/man2/wait.2:204
10853 "returns the exit status of the child. This consists of the least "
10854 "significant 8 bits of the I<status> argument that the child specified in a "
10855 "call to B<exit>(3) or B<_exit>(2) or as the argument for a return "
10856 "statement in main(). This macro should be employed only if B<WIFEXITED> "
10861 #: build/C/man2/wait.2:204
10863 msgid "B<WIFSIGNALED(>I<status>B<)>"
10866 #. type: Plain text
10867 #: build/C/man2/wait.2:207
10868 msgid "returns true if the child process was terminated by a signal."
10872 #: build/C/man2/wait.2:207
10874 msgid "B<WTERMSIG(>I<status>B<)>"
10877 #. type: Plain text
10878 #: build/C/man2/wait.2:214
10880 "returns the number of the signal that caused the child process to "
10881 "terminate. This macro should be employed only if B<WIFSIGNALED> returned "
10886 #: build/C/man2/wait.2:214
10888 msgid "B<WCOREDUMP(>I<status>B<)>"
10891 #. type: Plain text
10892 #: build/C/man2/wait.2:223
10894 "returns true if the child produced a core dump. This macro should be "
10895 "employed only if B<WIFSIGNALED> returned true. This macro is not specified "
10896 "in POSIX.1-2001 and is not available on some UNIX implementations (e.g., "
10897 "AIX, SunOS). Only use this enclosed in #ifdef WCOREDUMP ... #endif."
10901 #: build/C/man2/wait.2:223
10903 msgid "B<WIFSTOPPED(>I<status>B<)>"
10906 #. type: Plain text
10907 #: build/C/man2/wait.2:230
10909 "returns true if the child process was stopped by delivery of a signal; this "
10910 "is possible only if the call was done using B<WUNTRACED> or when the child "
10911 "is being traced (see B<ptrace>(2))."
10915 #: build/C/man2/wait.2:230
10917 msgid "B<WSTOPSIG(>I<status>B<)>"
10920 #. type: Plain text
10921 #: build/C/man2/wait.2:236
10923 "returns the number of the signal which caused the child to stop. This macro "
10924 "should be employed only if B<WIFSTOPPED> returned true."
10928 #: build/C/man2/wait.2:236
10930 msgid "B<WIFCONTINUED(>I<status>B<)>"
10933 #. type: Plain text
10934 #: build/C/man2/wait.2:241
10936 "(since Linux 2.6.10) returns true if the child process was resumed by "
10937 "delivery of B<SIGCONT>."
10941 #: build/C/man2/wait.2:241
10946 #. type: Plain text
10947 #: build/C/man2/wait.2:246
10949 "The B<waitid>() system call (available since Linux 2.6.9) provides more "
10950 "precise control over which child state changes to wait for."
10953 #. type: Plain text
10954 #: build/C/man2/wait.2:252
10956 "The I<idtype> and I<id> arguments select the child(ren) to wait for, as "
10961 #: build/C/man2/wait.2:252
10963 msgid "I<idtype> == B<P_PID>"
10966 #. type: Plain text
10967 #: build/C/man2/wait.2:255
10968 msgid "Wait for the child whose process ID matches I<id>."
10972 #: build/C/man2/wait.2:255
10974 msgid "I<idtype> == B<P_PGID>"
10977 #. type: Plain text
10978 #: build/C/man2/wait.2:258
10979 msgid "Wait for any child whose process group ID matches I<id>."
10983 #: build/C/man2/wait.2:258
10985 msgid "I<idtype> == B<P_ALL>"
10988 #. type: Plain text
10989 #: build/C/man2/wait.2:262
10990 msgid "Wait for any child; I<id> is ignored."
10993 #. type: Plain text
10994 #: build/C/man2/wait.2:266
10996 "The child state changes to wait for are specified by ORing one or more of "
10997 "the following flags in I<options>:"
11001 #: build/C/man2/wait.2:266
11006 #. type: Plain text
11007 #: build/C/man2/wait.2:269
11008 msgid "Wait for children that have terminated."
11012 #: build/C/man2/wait.2:269
11014 msgid "B<WSTOPPED>"
11017 #. type: Plain text
11018 #: build/C/man2/wait.2:272
11019 msgid "Wait for children that have been stopped by delivery of a signal."
11023 #: build/C/man2/wait.2:272
11025 msgid "B<WCONTINUED>"
11028 #. type: Plain text
11029 #: build/C/man2/wait.2:277
11031 "Wait for (previously stopped) children that have been resumed by delivery of "
11035 #. type: Plain text
11036 #: build/C/man2/wait.2:280
11037 msgid "The following flags may additionally be ORed in I<options>:"
11040 #. type: Plain text
11041 #: build/C/man2/wait.2:284
11042 msgid "As for B<waitpid>()."
11046 #: build/C/man2/wait.2:284
11051 #. type: Plain text
11052 #: build/C/man2/wait.2:288
11054 "Leave the child in a waitable state; a later wait call can be used to again "
11055 "retrieve the child status information."
11058 #. type: Plain text
11059 #: build/C/man2/wait.2:295
11061 "Upon successful return, B<waitid>() fills in the following fields of the "
11062 "I<siginfo_t> structure pointed to by I<infop>:"
11065 #. type: Plain text
11066 #: build/C/man2/wait.2:298
11067 msgid "The process ID of the child."
11070 #. type: Plain text
11071 #: build/C/man2/wait.2:302
11073 "The real user ID of the child. (This field is not set on most other "
11074 "implementations.)"
11077 #. type: Plain text
11078 #: build/C/man2/wait.2:306
11079 msgid "Always set to B<SIGCHLD>."
11083 #: build/C/man2/wait.2:306
11085 msgid "I<si_status>"
11088 #. type: Plain text
11089 #: build/C/man2/wait.2:316
11091 "Either the exit status of the child, as given to B<_exit>(2) (or "
11092 "B<exit>(3)), or the signal that caused the child to terminate, stop, or "
11093 "continue. The I<si_code> field can be used to determine how to interpret "
11097 #. type: Plain text
11098 #: build/C/man2/wait.2:333
11100 "Set to one of: B<CLD_EXITED> (child called B<_exit>(2)); B<CLD_KILLED> "
11101 "(child killed by signal); B<CLD_DUMPED> (child killed by signal, and dumped "
11102 "core); B<CLD_STOPPED> (child stopped by signal); B<CLD_TRAPPED> (traced "
11103 "child has trapped); or B<CLD_CONTINUED> (child continued by B<SIGCONT>)."
11106 #. POSIX.1-2001 leaves this possibility unspecified; most
11107 #. implementations (including Linux) zero out the structure
11108 #. in this case, but at least one implementation (AIX 5.1)
11109 #. does not -- MTK Nov 04
11110 #. type: Plain text
11111 #: build/C/man2/wait.2:355
11113 "If B<WNOHANG> was specified in I<options> and there were no children in a "
11114 "waitable state, then B<waitid>() returns 0 immediately and the state of the "
11115 "I<siginfo_t> structure pointed to by I<infop> is unspecified. To "
11116 "distinguish this case from that where a child was in a waitable state, zero "
11117 "out the I<si_pid> field before the call and check for a nonzero value in "
11118 "this field after the call returns."
11121 #. type: Plain text
11122 #: build/C/man2/wait.2:359
11124 "B<wait>(): on success, returns the process ID of the terminated child; on "
11125 "error, -1 is returned."
11128 #. type: Plain text
11129 #: build/C/man2/wait.2:368
11131 "B<waitpid>(): on success, returns the process ID of the child whose state "
11132 "has changed; if B<WNOHANG> was specified and one or more child(ren) "
11133 "specified by I<pid> exist, but have not yet changed state, then 0 is "
11134 "returned. On error, -1 is returned."
11137 #. FIXME As reported by Vegard Nossum, if infop is NULL, then waitid()
11138 #. returns the PID of the child. Either this is a bug, or it is intended
11139 #. behavior that needs to be documented. See my Jan 2009 LKML mail
11140 #. "waitid() return value strangeness when infop is NULL".
11141 #. type: Plain text
11142 #: build/C/man2/wait.2:381
11144 "B<waitid>(): returns 0 on success or if B<WNOHANG> was specified and no "
11145 "child(ren) specified by I<id> has yet changed state; on error, -1 is "
11149 #. type: Plain text
11150 #: build/C/man2/wait.2:385
11152 "Each of these calls sets I<errno> to an appropriate value in the case of an "
11157 #: build/C/man2/wait.2:386 build/C/man2/wait.2:391
11162 #. type: Plain text
11163 #: build/C/man2/wait.2:391
11165 "(for B<wait>()) The calling process does not have any unwaited-for "
11169 #. type: Plain text
11170 #: build/C/man2/wait.2:411
11172 "(for B<waitpid>() or B<waitid>()) The process specified by I<pid> "
11173 "(B<waitpid>()) or I<idtype> and I<id> (B<waitid>()) does not exist or is "
11174 "not a child of the calling process. (This can happen for one's own child if "
11175 "the action for B<SIGCHLD> is set to B<SIG_IGN>. See also the I<Linux Notes> "
11176 "section about threads.)"
11179 #. type: Plain text
11180 #: build/C/man2/wait.2:418
11182 "B<WNOHANG> was not set and an unblocked signal or a B<SIGCHLD> was caught; "
11183 "see B<signal>(7)."
11186 #. type: Plain text
11187 #: build/C/man2/wait.2:423
11188 msgid "The I<options> argument was invalid."
11191 #. type: Plain text
11192 #: build/C/man2/wait.2:438
11194 "A child that terminates, but has not been waited for becomes a \"zombie\". "
11195 "The kernel maintains a minimal set of information about the zombie process "
11196 "(PID, termination status, resource usage information) in order to allow the "
11197 "parent to later perform a wait to obtain information about the child. As "
11198 "long as a zombie is not removed from the system via a wait, it will consume "
11199 "a slot in the kernel process table, and if this table fills, it will not be "
11200 "possible to create further processes. If a parent process terminates, then "
11201 "its \"zombie\" children (if any) are adopted by B<init>(1), which "
11202 "automatically performs a wait to remove the zombies."
11205 #. type: Plain text
11206 #: build/C/man2/wait.2:467
11208 "POSIX.1-2001 specifies that if the disposition of B<SIGCHLD> is set to "
11209 "B<SIG_IGN> or the B<SA_NOCLDWAIT> flag is set for B<SIGCHLD> (see "
11210 "B<sigaction>(2)), then children that terminate do not become zombies and a "
11211 "call to B<wait>() or B<waitpid>() will block until all children have "
11212 "terminated, and then fail with I<errno> set to B<ECHILD>. (The original "
11213 "POSIX standard left the behavior of setting B<SIGCHLD> to B<SIG_IGN> "
11214 "unspecified. Note that even though the default disposition of B<SIGCHLD> is "
11215 "\"ignore\", explicitly setting the disposition to B<SIG_IGN> results in "
11216 "different treatment of zombie process children.)"
11219 #. type: Plain text
11220 #: build/C/man2/wait.2:480
11222 "Linux 2.6 conforms to the POSIX requirements. However, Linux 2.4 (and "
11223 "earlier) does not: if a B<wait>() or B<waitpid>() call is made while "
11224 "B<SIGCHLD> is being ignored, the call behaves just as though B<SIGCHLD> were "
11225 "not being ignored, that is, the call blocks until the next child terminates "
11226 "and then returns the process ID and status of that child."
11229 #. type: Plain text
11230 #: build/C/man2/wait.2:496
11232 "In the Linux kernel, a kernel-scheduled thread is not a distinct construct "
11233 "from a process. Instead, a thread is simply a process that is created using "
11234 "the Linux-unique B<clone>(2) system call; other routines such as the "
11235 "portable B<pthread_create>(3) call are implemented using B<clone>(2). "
11236 "Before Linux 2.4, a thread was just a special case of a process, and as a "
11237 "consequence one thread could not wait on the children of another thread, "
11238 "even when the latter belongs to the same thread group. However, POSIX "
11239 "prescribes such functionality, and since Linux 2.4 a thread can, and by "
11240 "default will, wait on children of other threads in the same thread group."
11243 #. type: Plain text
11244 #: build/C/man2/wait.2:503
11246 "The following Linux-specific I<options> are for use with children created "
11247 "using B<clone>(2); they cannot be used with B<waitid>():"
11251 #: build/C/man2/wait.2:503
11253 msgid "B<__WCLONE>"
11257 #. type: Plain text
11258 #: build/C/man2/wait.2:514
11260 "Wait for \"clone\" children only. If omitted, then wait for \"non-clone\" "
11261 "children only. (A \"clone\" child is one which delivers no signal, or a "
11262 "signal other than B<SIGCHLD> to its parent upon termination.) This option "
11263 "is ignored if B<__WALL> is also specified."
11267 #: build/C/man2/wait.2:514
11269 msgid "B<__WALL> (since Linux 2.4)"
11272 #. since patch-2.3.48
11273 #. type: Plain text
11274 #: build/C/man2/wait.2:519
11275 msgid "Wait for all children, regardless of type (\"clone\" or \"non-clone\")."
11279 #: build/C/man2/wait.2:519
11281 msgid "B<__WNOTHREAD> (since Linux 2.4)"
11284 #. since patch-2.4.0-test8
11285 #. type: Plain text
11286 #: build/C/man2/wait.2:525
11288 "Do not wait for children of other threads in the same thread group. This "
11289 "was the default before Linux 2.4."
11292 #. type: Plain text
11293 #: build/C/man2/wait.2:537
11295 "The raw B<waitid>() system call takes a fifth argument, of type I<struct "
11296 "rusage\\ *>. If this argument is non-NULL, then it is used to return "
11297 "resource usage information about the child, in the same manner as "
11298 "B<wait4>(2). See B<getrusage>(2) for details."
11301 #. type: Plain text
11302 #: build/C/man2/wait.2:552
11304 "According to POSIX.1-2008, an application calling B<waitid>() must ensure "
11305 "that I<infop> points to a I<siginfo_t> structure (i.e., that it is a "
11306 "non-null pointer). On Linux, if I<infop> is NULL, B<waitid>() succeeds, "
11307 "and returns the process ID of the waited-for child. Applications should "
11308 "avoid relying on this inconsistent, nonstandard, and unnecessary feature."
11311 #. fork.2 refers to this example program.
11312 #. type: Plain text
11313 #: build/C/man2/wait.2:569
11315 "The following program demonstrates the use of B<fork>(2) and B<waitpid>(). "
11316 "The program creates a child process. If no command-line argument is "
11317 "supplied to the program, then the child suspends its execution using "
11318 "B<pause>(2), to allow the user to send signals to the child. Otherwise, if "
11319 "a command-line argument is supplied, then the child exits immediately, using "
11320 "the integer supplied on the command line as the exit status. The parent "
11321 "process executes a loop that monitors the child using B<waitpid>(), and uses "
11322 "the W*() macros described above to analyze the wait status value."
11325 #. type: Plain text
11326 #: build/C/man2/wait.2:585
11330 "Child PID is 32360\n"
11332 "$B< kill -STOP 32360>\n"
11333 "stopped by signal 19\n"
11334 "$B< kill -CONT 32360>\n"
11336 "$B< kill -TERM 32360>\n"
11337 "killed by signal 15\n"
11338 "[1]+ Done ./a.out\n"
11342 #. type: Plain text
11343 #: build/C/man2/wait.2:594
11346 "#include E<lt>sys/wait.hE<gt>\n"
11347 "#include E<lt>stdlib.hE<gt>\n"
11348 "#include E<lt>unistd.hE<gt>\n"
11349 "#include E<lt>stdio.hE<gt>\n"
11352 #. type: Plain text
11353 #: build/C/man2/wait.2:600
11357 "main(int argc, char *argv[])\n"
11359 " pid_t cpid, w;\n"
11363 #. type: Plain text
11364 #: build/C/man2/wait.2:606
11367 " cpid = fork();\n"
11368 " if (cpid == -1) {\n"
11369 " perror(\"fork\");\n"
11370 " exit(EXIT_FAILURE);\n"
11374 #. type: Plain text
11375 #: build/C/man2/wait.2:612
11378 " if (cpid == 0) { /* Code executed by child */\n"
11379 " printf(\"Child PID is %ld\\en\", (long) getpid());\n"
11380 " if (argc == 1)\n"
11381 " pause(); /* Wait for signals */\n"
11382 " _exit(atoi(argv[1]));\n"
11385 #. type: Plain text
11386 #: build/C/man2/wait.2:620
11389 " } else { /* Code executed by parent */\n"
11391 " w = waitpid(cpid, &status, WUNTRACED | WCONTINUED);\n"
11392 " if (w == -1) {\n"
11393 " perror(\"waitpid\");\n"
11394 " exit(EXIT_FAILURE);\n"
11398 #. type: Plain text
11399 #: build/C/man2/wait.2:634
11402 " if (WIFEXITED(status)) {\n"
11403 " printf(\"exited, status=%d\\en\", WEXITSTATUS(status));\n"
11404 " } else if (WIFSIGNALED(status)) {\n"
11405 " printf(\"killed by signal %d\\en\", WTERMSIG(status));\n"
11406 " } else if (WIFSTOPPED(status)) {\n"
11407 " printf(\"stopped by signal %d\\en\", WSTOPSIG(status));\n"
11408 " } else if (WIFCONTINUED(status)) {\n"
11409 " printf(\"continued\\en\");\n"
11411 " } while (!WIFEXITED(status) && !WIFSIGNALED(status));\n"
11412 " exit(EXIT_SUCCESS);\n"
11417 #. type: Plain text
11418 #: build/C/man2/wait.2:647
11420 "B<_exit>(2), B<clone>(2), B<fork>(2), B<kill>(2), B<ptrace>(2), "
11421 "B<sigaction>(2), B<signal>(2), B<wait4>(2), B<pthread_create>(3), "
11422 "B<credentials>(7), B<signal>(7)"
11426 #: build/C/man2/wait4.2:33
11432 #: build/C/man2/wait4.2:33
11437 #. type: Plain text
11438 #: build/C/man2/wait4.2:36
11439 msgid "wait3, wait4 - wait for process to change state, BSD style"
11442 #. type: Plain text
11443 #: build/C/man2/wait4.2:42
11446 "B<#include E<lt>sys/types.hE<gt>>\n"
11447 "B<#include E<lt>sys/time.hE<gt>>\n"
11448 "B<#include E<lt>sys/resource.hE<gt>>\n"
11449 "B<#include E<lt>sys/wait.hE<gt>>\n"
11452 #. type: Plain text
11453 #: build/C/man2/wait4.2:45
11456 "B<pid_t wait3(int *>I<status>B<, int >I<options>B<,>\n"
11457 "B< struct rusage *>I<rusage>B<);>\n"
11460 #. type: Plain text
11461 #: build/C/man2/wait4.2:48
11464 "B<pid_t wait4(pid_t >I<pid>B<, int *>I<status>B<, int >I<options>B<,>\n"
11465 "B< struct rusage *>I<rusage>B<);>\n"
11468 #. type: Plain text
11469 #: build/C/man2/wait4.2:57
11470 msgid "B<wait3>():"
11473 #. type: Plain text
11474 #: build/C/man2/wait4.2:63
11475 msgid "B<wait4>():"
11478 #. type: Plain text
11479 #: build/C/man2/wait4.2:65
11480 msgid "_BSD_SOURCE"
11483 #. type: Plain text
11484 #: build/C/man2/wait4.2:73
11486 "These functions are obsolete; use B<waitpid>(2) or B<waitid>(2) in new "
11490 #. type: Plain text
11491 #: build/C/man2/wait4.2:83
11493 "The B<wait3>() and B<wait4>() system calls are similar to B<waitpid>(2), "
11494 "but additionally return resource usage information about the child in the "
11495 "structure pointed to by I<rusage>."
11498 #. type: Plain text
11499 #: build/C/man2/wait4.2:89
11501 "Other than the use of the I<rusage> argument, the following B<wait3>() "
11505 #. type: Plain text
11506 #: build/C/man2/wait4.2:92
11508 msgid " wait3(status, options, rusage);\n"
11511 #. type: Plain text
11512 #: build/C/man2/wait4.2:95 build/C/man2/wait4.2:109
11513 msgid "is equivalent to:"
11516 #. type: Plain text
11517 #: build/C/man2/wait4.2:98
11519 msgid " waitpid(-1, status, options);\n"
11522 #. type: Plain text
11523 #: build/C/man2/wait4.2:103
11524 msgid "Similarly, the following B<wait4>() call:"
11527 #. type: Plain text
11528 #: build/C/man2/wait4.2:106
11530 msgid " wait4(pid, status, options, rusage);\n"
11533 #. type: Plain text
11534 #: build/C/man2/wait4.2:112
11536 msgid " waitpid(pid, status, options);\n"
11539 #. type: Plain text
11540 #: build/C/man2/wait4.2:122
11542 "In other words, B<wait3>() waits of any child, while B<wait4>() can be "
11543 "used to select a specific child, or children, on which to wait. See "
11544 "B<wait>(2) for further details."
11547 #. type: Plain text
11548 #: build/C/man2/wait4.2:132
11550 "If I<rusage> is not NULL, the I<struct rusage> to which it points will be "
11551 "filled with accounting information about the child. See B<getrusage>(2) "
11555 #. type: Plain text
11556 #: build/C/man2/wait4.2:135 build/C/man2/wait4.2:138
11557 msgid "As for B<waitpid>(2)."
11560 #. type: Plain text
11561 #: build/C/man2/wait4.2:140
11565 #. type: Plain text
11566 #: build/C/man2/wait4.2:147
11568 "SUSv1 included a specification of B<wait3>(); SUSv2 included B<wait3>(), but "
11569 "marked it LEGACY; SUSv3 removed it."
11572 #. type: Plain text
11573 #: build/C/man2/wait4.2:159
11575 "Including I<E<lt>sys/time.hE<gt>> is not required these days, but increases "
11576 "portability. (Indeed, I<E<lt>sys/resource.hE<gt>> defines the I<rusage> "
11577 "structure with fields of type I<struct timeval> defined in "
11578 "I<E<lt>sys/time.hE<gt>>.)"
11581 #. type: Plain text
11582 #: build/C/man2/wait4.2:165
11584 "On Linux, B<wait3>() is a library function implemented on top of the "
11585 "B<wait4>() system call."
11588 #. type: Plain text
11589 #: build/C/man2/wait4.2:172
11591 "B<fork>(2), B<getrusage>(2), B<sigaction>(2), B<signal>(2), B<wait>(2), "