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: 2012-04-25 05:36+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=CHARSET\n"
17 "Content-Transfer-Encoding: 8bit\n"
20 #: build/C/man3/bsd_signal.3:23
26 #: build/C/man3/bsd_signal.3:23 build/C/man2/getitimer.2:7
32 #: build/C/man3/bsd_signal.3:23 build/C/man2/eventfd.2:21 build/C/man2/getitimer.2:7 build/C/man3/gsignal.3:25 build/C/man2/kill.2:44 build/C/man2/killpg.2:40 build/C/man2/pause.2:30 build/C/man2/prctl.2:46 build/C/man3/profil.3:28 build/C/man3/psignal.3:28 build/C/man3/raise.3:27 build/C/man2/rt_sigqueueinfo.2:23 build/C/man2/sgetmask.2:24 build/C/man2/sigaction.2:45 build/C/man2/sigaltstack.2:25 build/C/man7/sigevent.7:24 build/C/man3/siginterrupt.3:29 build/C/man2/signal.2:34 build/C/man7/signal.7:44 build/C/man2/signalfd.2:19 build/C/man3/sigpause.3:23 build/C/man2/sigpending.2:27 build/C/man2/sigprocmask.2:27 build/C/man3/sigqueue.3:26 build/C/man2/sigreturn.2:27 build/C/man3/sigset.3:24 build/C/man3/sigsetops.3:29 build/C/man2/sigsuspend.2:27 build/C/man3/sigvec.3:24 build/C/man3/sigwait.3:24 build/C/man2/sigwaitinfo.2:23 build/C/man3/sysv_signal.3:23 build/C/man2/timer_create.2:29 build/C/man2/timer_delete.2:23 build/C/man2/timer_getoverrun.2:23 build/C/man2/timer_settime.2:23 build/C/man2/timerfd_create.2:20 build/C/man2/tkill.2:29 build/C/man2/wait.2:50 build/C/man2/wait4.2:34
34 msgid "Linux Programmer's Manual"
38 #: build/C/man3/bsd_signal.3:24 build/C/man2/eventfd.2:22 build/C/man2/getitimer.2:8 build/C/man3/gsignal.3:26 build/C/man2/kill.2:45 build/C/man2/killpg.2:41 build/C/man2/pause.2:31 build/C/man2/prctl.2:47 build/C/man3/profil.3:29 build/C/man3/psignal.3:29 build/C/man3/raise.3:28 build/C/man2/rt_sigqueueinfo.2:24 build/C/man2/sgetmask.2:25 build/C/man2/sigaction.2:46 build/C/man2/sigaltstack.2:26 build/C/man7/sigevent.7:25 build/C/man3/siginterrupt.3:30 build/C/man2/signal.2:35 build/C/man7/signal.7:45 build/C/man2/signalfd.2:20 build/C/man3/sigpause.3:24 build/C/man2/sigpending.2:28 build/C/man2/sigprocmask.2:28 build/C/man3/sigqueue.3:27 build/C/man2/sigreturn.2:28 build/C/man3/sigset.3:25 build/C/man3/sigsetops.3:30 build/C/man2/sigsuspend.2:28 build/C/man3/sigvec.3:25 build/C/man3/sigwait.3:25 build/C/man2/sigwaitinfo.2:24 build/C/man3/sysv_signal.3:24 build/C/man2/timer_create.2:30 build/C/man2/timer_delete.2:24 build/C/man2/timer_getoverrun.2:24 build/C/man2/timer_settime.2:24 build/C/man2/timerfd_create.2:21 build/C/man2/tkill.2:30 build/C/man2/wait.2:51 build/C/man2/wait4.2:35
44 #: build/C/man3/bsd_signal.3:26
45 msgid "bsd_signal - signal handling with BSD semantics"
49 #: build/C/man3/bsd_signal.3:26 build/C/man2/eventfd.2:24 build/C/man2/getitimer.2:10 build/C/man3/gsignal.3:28 build/C/man2/kill.2:47 build/C/man2/killpg.2:43 build/C/man2/pause.2:33 build/C/man2/prctl.2:49 build/C/man3/profil.3:31 build/C/man3/psignal.3:31 build/C/man3/raise.3:30 build/C/man2/rt_sigqueueinfo.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/man2/signalfd.2:22 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.2:30 build/C/man3/sigset.3:27 build/C/man3/sigsetops.3:33 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.2:32 build/C/man2/timer_delete.2:26 build/C/man2/timer_getoverrun.2:26 build/C/man2/timer_settime.2:27 build/C/man2/timerfd_create.2:24 build/C/man2/tkill.2:32 build/C/man2/wait.2:53 build/C/man2/wait4.2:37
55 #: build/C/man3/bsd_signal.3:28
56 msgid "B<#define _XOPEN_SOURCE> /* See feature_test_macros(7) */"
60 #: build/C/man3/bsd_signal.3:30 build/C/man2/killpg.2:45 build/C/man2/sigaltstack.2:30 build/C/man2/signal.2:39 build/C/man2/sigpending.2:32 build/C/man2/sigprocmask.2:32 build/C/man3/sigqueue.3:31 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/sysv_signal.3:30
61 msgid "B<#include E<lt>signal.hE<gt>>"
65 #: build/C/man3/bsd_signal.3:32 build/C/man2/signal.2:41 build/C/man3/sigset.3:31 build/C/man3/sysv_signal.3:32
66 msgid "B<typedef void (*sighandler_t)(int);>"
70 #: build/C/man3/bsd_signal.3:34
71 msgid "B<sighandler_t bsd_signal(int >I<signum>B<, sighandler_t >I<handler>B<);>"
75 #: build/C/man3/bsd_signal.3:34 build/C/man2/eventfd.2:28 build/C/man2/getitimer.2:19 build/C/man3/gsignal.3:47 build/C/man2/kill.2:65 build/C/man2/killpg.2:59 build/C/man2/pause.2:37 build/C/man2/prctl.2:56 build/C/man3/profil.3:44 build/C/man3/psignal.3:54 build/C/man3/raise.3:36 build/C/man2/rt_sigqueueinfo.2:33 build/C/man2/sgetmask.2:31 build/C/man2/sigaction.2:65 build/C/man2/sigaltstack.2:49 build/C/man7/sigevent.7:50 build/C/man3/siginterrupt.3:53 build/C/man2/signal.2:43 build/C/man7/signal.7:47 build/C/man2/signalfd.2:26 build/C/man3/sigpause.3:34 build/C/man2/sigpending.2:44 build/C/man2/sigprocmask.2:45 build/C/man3/sigqueue.3:41 build/C/man2/sigreturn.2:32 build/C/man3/sigset.3:56 build/C/man3/sigsetops.3:61 build/C/man2/sigsuspend.2:44 build/C/man3/sigvec.3:47 build/C/man3/sigwait.3:43 build/C/man2/sigwaitinfo.2:44 build/C/man3/sysv_signal.3:34 build/C/man2/timer_create.2:50 build/C/man2/timer_delete.2:42 build/C/man2/timer_getoverrun.2:42 build/C/man2/timer_settime.2:47 build/C/man2/timerfd_create.2:36 build/C/man2/tkill.2:38 build/C/man2/wait.2:82 build/C/man2/wait4.2:68
81 #: build/C/man3/bsd_signal.3:39
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.3:52
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.3:52 build/C/man2/eventfd.2:222 build/C/man2/getitimer.2:117 build/C/man2/kill.2:99 build/C/man2/killpg.2:88 build/C/man2/pause.2:42 build/C/man2/prctl.2:515 build/C/man3/profil.3:66 build/C/man3/psignal.3:87 build/C/man3/raise.3:59 build/C/man2/rt_sigqueueinfo.2:124 build/C/man2/sgetmask.2:54 build/C/man2/sigaction.2:658 build/C/man2/sigaltstack.2:131 build/C/man3/siginterrupt.3:71 build/C/man2/signal.2:95 build/C/man2/signalfd.2:248 build/C/man3/sigpause.3:46 build/C/man2/sigpending.2:51 build/C/man2/sigprocmask.2:91 build/C/man3/sigqueue.3:81 build/C/man2/sigreturn.2:51 build/C/man3/sigset.3:127 build/C/man3/sigsetops.3:105 build/C/man2/sigsuspend.2:68 build/C/man3/sigvec.3:197 build/C/man3/sigwait.3:66 build/C/man2/sigwaitinfo.2:98 build/C/man3/sysv_signal.3:49 build/C/man2/timer_create.2:165 build/C/man2/timer_delete.2:50 build/C/man2/timer_getoverrun.2:79 build/C/man2/timer_settime.2:169 build/C/man2/timerfd_create.2:286 build/C/man2/tkill.2:69 build/C/man2/wait.2:354 build/C/man2/wait4.2:127
106 #: build/C/man3/bsd_signal.3:58
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.3:58 build/C/man2/eventfd.2:229 build/C/man2/getitimer.2:122 build/C/man2/kill.2:104 build/C/man2/killpg.2:93 build/C/man2/pause.2:53 build/C/man2/prctl.2:532 build/C/man2/rt_sigqueueinfo.2:129 build/C/man2/sgetmask.2:59 build/C/man2/sigaction.2:661 build/C/man2/sigaltstack.2:135 build/C/man3/siginterrupt.3:76 build/C/man2/signal.2:100 build/C/man2/signalfd.2:262 build/C/man2/sigpending.2:54 build/C/man2/sigprocmask.2:94 build/C/man3/sigqueue.3:89 build/C/man3/sigset.3:152 build/C/man3/sigsetops.3:121 build/C/man2/sigsuspend.2:72 build/C/man3/sigvec.3:214 build/C/man3/sigwait.3:71 build/C/man2/sigwaitinfo.2:107 build/C/man3/sysv_signal.3:55 build/C/man2/timer_create.2:173 build/C/man2/timer_delete.2:57 build/C/man2/timer_getoverrun.2:87 build/C/man2/timer_settime.2:178 build/C/man2/timerfd_create.2:301 build/C/man2/tkill.2:73 build/C/man2/wait.2:383 build/C/man2/wait4.2:130
119 #: build/C/man3/bsd_signal.3:61 build/C/man3/sysv_signal.3:58
120 msgid "As for B<signal>(2)."
124 #: build/C/man3/bsd_signal.3:61 build/C/man2/eventfd.2:266 build/C/man2/getitimer.2:143 build/C/man3/gsignal.3:93 build/C/man2/kill.2:120 build/C/man2/killpg.2:110 build/C/man2/pause.2:57 build/C/man2/prctl.2:694 build/C/man3/profil.3:68 build/C/man3/psignal.3:97 build/C/man3/raise.3:62 build/C/man2/rt_sigqueueinfo.2:171 build/C/man2/sgetmask.2:61 build/C/man2/sigaction.2:673 build/C/man2/sigaltstack.2:154 build/C/man7/sigevent.7:128 build/C/man3/siginterrupt.3:80 build/C/man2/signal.2:105 build/C/man7/signal.7:834 build/C/man2/signalfd.2:304 build/C/man3/sigpause.3:54 build/C/man2/sigpending.2:59 build/C/man2/sigprocmask.2:107 build/C/man3/sigqueue.3:112 build/C/man2/sigreturn.2:58 build/C/man3/sigset.3:171 build/C/man3/sigsetops.3:126 build/C/man2/sigsuspend.2:80 build/C/man3/sigvec.3:219 build/C/man3/sigwait.3:77 build/C/man2/sigwaitinfo.2:126 build/C/man3/sysv_signal.3:58 build/C/man2/timer_create.2:191 build/C/man2/timer_delete.2:64 build/C/man2/timer_getoverrun.2:94 build/C/man2/timer_settime.2:203 build/C/man2/timerfd_create.2:370 build/C/man2/tkill.2:90 build/C/man2/wait.2:421 build/C/man2/wait4.2:133
126 msgid "CONFORMING TO"
130 #: build/C/man3/bsd_signal.3:68
132 "4.2BSD, POSIX.1-2001. POSIX.1-2008 removes the specification of "
133 "B<bsd_signal>(), recommending the use of B<sigaction>(2) instead."
137 #: build/C/man3/bsd_signal.3:68 build/C/man2/eventfd.2:271 build/C/man2/getitimer.2:153 build/C/man2/kill.2:122 build/C/man2/killpg.2:114 build/C/man2/rt_sigqueueinfo.2:173 build/C/man2/sgetmask.2:63 build/C/man2/sigaction.2:676 build/C/man2/sigaltstack.2:156 build/C/man2/signal.2:107 build/C/man2/signalfd.2:309 build/C/man3/sigpause.3:58 build/C/man2/sigpending.2:61 build/C/man2/sigprocmask.2:109 build/C/man3/sigqueue.3:114 build/C/man2/sigreturn.2:62 build/C/man3/sigset.3:188 build/C/man3/sigsetops.3:128 build/C/man2/sigsuspend.2:82 build/C/man3/sigvec.3:225 build/C/man3/sigwait.3:79 build/C/man2/sigwaitinfo.2:128 build/C/man3/sysv_signal.3:60 build/C/man2/timer_create.2:193 build/C/man2/timer_getoverrun.2:96 build/C/man2/tkill.2:96 build/C/man2/wait.2:423 build/C/man2/wait4.2:135
143 #: build/C/man3/bsd_signal.3:74
144 msgid "Use of B<bsd_signal>() should be avoided; use B<sigaction>(2) instead."
148 #: build/C/man3/bsd_signal.3:85
150 "On modern Linux systems, B<bsd_signal>() and B<signal>(2) are equivalent. "
151 "But on older systems, B<signal>(2) provided unreliable signal semantics; "
152 "see B<signal>(2) for details."
156 #: build/C/man3/bsd_signal.3:92 build/C/man3/sysv_signal.3:85
158 "The use of I<sighandler_t> is a GNU extension; this type is only defined if "
159 "the B<_GNU_SOURCE> feature test macro is defined."
163 #: build/C/man3/bsd_signal.3:92 build/C/man2/eventfd.2:417 build/C/man2/getitimer.2:219 build/C/man3/gsignal.3:101 build/C/man2/kill.2:170 build/C/man2/killpg.2:133 build/C/man2/pause.2:59 build/C/man2/prctl.2:708 build/C/man3/profil.3:79 build/C/man3/psignal.3:111 build/C/man3/raise.3:64 build/C/man2/rt_sigqueueinfo.2:183 build/C/man2/sgetmask.2:74 build/C/man2/sigaction.2:789 build/C/man2/sigaltstack.2:230 build/C/man7/sigevent.7:130 build/C/man3/siginterrupt.3:89 build/C/man2/signal.2:259 build/C/man7/signal.7:845 build/C/man2/signalfd.2:430 build/C/man3/sigpause.3:96 build/C/man2/sigpending.2:82 build/C/man2/sigprocmask.2:139 build/C/man3/sigqueue.3:147 build/C/man2/sigreturn.2:72 build/C/man3/sigset.3:264 build/C/man3/sigsetops.3:166 build/C/man2/sigsuspend.2:104 build/C/man3/sigvec.3:250 build/C/man3/sigwait.3:86 build/C/man2/sigwaitinfo.2:179 build/C/man3/sysv_signal.3:85 build/C/man2/timer_create.2:397 build/C/man2/timer_delete.2:66 build/C/man2/timer_getoverrun.2:128 build/C/man2/timer_settime.2:208 build/C/man2/timerfd_create.2:540 build/C/man2/tkill.2:105 build/C/man2/wait.2:605 build/C/man2/wait4.2:153
169 #: build/C/man3/bsd_signal.3:96
170 msgid "B<sigaction>(2), B<signal>(2), B<sysv_signal>(3), B<signal>(7)"
174 #: build/C/man2/eventfd.2:21
180 #: build/C/man2/eventfd.2:21
186 #: build/C/man2/eventfd.2:21 build/C/man2/getitimer.2:7 build/C/man2/kill.2:44 build/C/man2/killpg.2:40 build/C/man2/pause.2:30 build/C/man2/prctl.2:46 build/C/man3/profil.3:28 build/C/man2/rt_sigqueueinfo.2:23 build/C/man2/sgetmask.2:24 build/C/man2/sigaction.2:45 build/C/man2/sigaltstack.2:25 build/C/man2/signal.2:34 build/C/man7/signal.7:44 build/C/man2/signalfd.2:19 build/C/man3/sigpause.3:23 build/C/man2/sigpending.2:27 build/C/man2/sigprocmask.2:27 build/C/man3/sigqueue.3:26 build/C/man2/sigreturn.2:27 build/C/man3/sigset.3:24 build/C/man3/sigsetops.3:29 build/C/man2/sigsuspend.2:27 build/C/man3/sigvec.3:24 build/C/man3/sigwait.3:24 build/C/man2/sigwaitinfo.2:23 build/C/man2/timer_create.2:29 build/C/man2/timer_delete.2:23 build/C/man2/timer_getoverrun.2:23 build/C/man2/timer_settime.2:23 build/C/man2/timerfd_create.2:20 build/C/man2/tkill.2:29 build/C/man2/wait.2:50 build/C/man2/wait4.2:34
192 #: build/C/man2/eventfd.2:24
193 msgid "eventfd - create a file descriptor for event notification"
197 #: build/C/man2/eventfd.2:26
198 msgid "B<#include E<lt>sys/eventfd.hE<gt>>"
202 #: build/C/man2/eventfd.2:28
203 msgid "B<int eventfd(unsigned int >I<initval>B<, int >I<flags>B<);>"
207 #: build/C/man2/eventfd.2:38
209 "B<eventfd>() creates an \"eventfd object\" that can be used as an event "
210 "wait/notify mechanism by userspace applications, and by the kernel to notify "
211 "userspace applications of events. The object contains an unsigned 64-bit "
212 "integer (I<uint64_t>) counter that is maintained by the kernel. This "
213 "counter is initialized with the value specified in the argument I<initval>."
217 #: build/C/man2/eventfd.2:43
219 "The following values may be bitwise ORed in I<flags> to change the behaviour "
224 #: build/C/man2/eventfd.2:43
226 msgid "B<EFD_CLOEXEC> (since Linux 2.6.27)"
230 #: build/C/man2/eventfd.2:53 build/C/man2/signalfd.2:94 build/C/man2/timerfd_create.2:102
232 "Set the close-on-exec (B<FD_CLOEXEC>) flag on the new file descriptor. See "
233 "the description of the B<O_CLOEXEC> flag in B<open>(2) for reasons why this "
238 #: build/C/man2/eventfd.2:53
240 msgid "B<EFD_NONBLOCK> (since Linux 2.6.27)"
244 #: build/C/man2/eventfd.2:61 build/C/man2/signalfd.2:84 build/C/man2/timerfd_create.2:92
246 "Set the B<O_NONBLOCK> file status flag on the new open file description. "
247 "Using this flag saves extra calls to B<fcntl>(2) to achieve the same "
252 #: build/C/man2/eventfd.2:61
254 msgid "B<EFD_SEMAPHORE> (since Linux 2.6.30)"
258 #: build/C/man2/eventfd.2:65
260 "Provide semaphore-like semantics for reads from the new file descriptor. "
265 #: build/C/man2/eventfd.2:69 build/C/man2/signalfd.2:98
267 "In Linux up to version 2.6.26, the I<flags> argument is unused, and must be "
272 #: build/C/man2/eventfd.2:75
274 "As its return value, B<eventfd>() returns a new file descriptor that can be "
275 "used to refer to the eventfd object. The following operations can be "
276 "performed on the file descriptor:"
280 #: build/C/man2/eventfd.2:75 build/C/man2/signalfd.2:101 build/C/man2/timerfd_create.2:210
286 #: build/C/man2/eventfd.2:85
288 "Each successful B<read>(2) returns an 8-byte integer. A B<read>(2) will "
289 "fail with the error B<EINVAL> if the size of the supplied buffer is less "
294 #: build/C/man2/eventfd.2:90
296 "The value returned by B<read>(2) is in host byte order, i.e., the native "
297 "byte order for integers on the host machine."
301 #: build/C/man2/eventfd.2:97
303 "The semantics of B<read>(2) depend on whether the eventfd counter currently "
304 "has a nonzero value and whether the B<EFD_SEMAPHORE> flag was specified when "
305 "creating the eventfd file descriptor:"
309 #: build/C/man2/eventfd.2:98 build/C/man2/eventfd.2:105 build/C/man2/eventfd.2:112 build/C/man2/eventfd.2:157 build/C/man2/eventfd.2:167 build/C/man2/eventfd.2:177 build/C/man2/prctl.2:575 build/C/man2/prctl.2:580 build/C/man2/prctl.2:585 build/C/man2/prctl.2:595 build/C/man3/psignal.3:103 build/C/man3/psignal.3:107 build/C/man2/sigaction.2:294 build/C/man2/sigaction.2:309 build/C/man2/sigaction.2:325 build/C/man2/sigaction.2:340 build/C/man2/sigaction.2:387 build/C/man2/sigaction.2:423 build/C/man2/signal.2:66 build/C/man2/signal.2:71 build/C/man2/signal.2:78 build/C/man2/signal.2:205 build/C/man2/signal.2:209 build/C/man2/signal.2:248 build/C/man7/signal.7:147 build/C/man7/signal.7:155 build/C/man7/signal.7:611 build/C/man7/signal.7:613 build/C/man7/signal.7:634 build/C/man7/signal.7:649 build/C/man7/signal.7:653 build/C/man7/signal.7:660 build/C/man7/signal.7:676 build/C/man7/signal.7:682 build/C/man7/signal.7:689 build/C/man7/signal.7:694 build/C/man7/signal.7:713 build/C/man7/signal.7:732 build/C/man7/signal.7:739 build/C/man7/signal.7:748 build/C/man7/signal.7:756 build/C/man7/signal.7:762 build/C/man7/signal.7:767 build/C/man7/signal.7:787 build/C/man7/signal.7:806 build/C/man7/signal.7:809 build/C/man7/signal.7:812 build/C/man7/signal.7:815 build/C/man7/signal.7:820 build/C/man7/signal.7:826 build/C/man7/signal.7:830 build/C/man3/sigwait.3:59 build/C/man3/sigwait.3:64 build/C/man2/timer_create.2:214 build/C/man2/timer_create.2:217 build/C/man2/timer_create.2:220 build/C/man2/timer_create.2:224 build/C/man2/timer_create.2:227 build/C/man2/timer_create.2:233 build/C/man2/timer_create.2:237
315 #: build/C/man2/eventfd.2:105
317 "If B<EFD_SEMAPHORE> was not specified and the eventfd counter has a nonzero "
318 "value, then a B<read>(2) returns 8 bytes containing that value, and the "
319 "counter's value is reset to zero."
323 #: build/C/man2/eventfd.2:112
325 "If B<EFD_SEMAPHORE> was specified and the eventfd counter has a nonzero "
326 "value, then a B<read>(2) returns 8 bytes containing the value 1, and the "
327 "counter's value is decremented by 1."
331 #: build/C/man2/eventfd.2:122
333 "If the eventfd counter is zero at the time of the call to B<read>(2), then "
334 "the call either blocks until the counter becomes nonzero (at which time, the "
335 "B<read>(2) proceeds as described above) or fails with the error B<EAGAIN> "
336 "if the file descriptor has been made nonblocking."
340 #: build/C/man2/eventfd.2:123
346 #: build/C/man2/eventfd.2:140
348 "A B<write>(2) call adds the 8-byte integer value supplied in its buffer to "
349 "the counter. The maximum value that may be stored in the counter is the "
350 "largest unsigned 64-bit value minus 1 (i.e., 0xfffffffffffffffe). If the "
351 "addition would cause the counter's value to exceed the maximum, then the "
352 "B<write>(2) either blocks until a B<read>(2) is performed on the file "
353 "descriptor, or fails with the error B<EAGAIN> if the file descriptor has "
354 "been made nonblocking."
358 #: build/C/man2/eventfd.2:147
360 "A B<write>(2) will fail with the error B<EINVAL> if the size of the "
361 "supplied buffer is less than 8 bytes, or if an attempt is made to write the "
362 "value 0xffffffffffffffff."
366 #: build/C/man2/eventfd.2:147 build/C/man2/signalfd.2:139 build/C/man2/timerfd_create.2:243
368 msgid "B<poll>(2), B<select>(2) (and similar)"
372 #: build/C/man2/eventfd.2:156
374 "The returned file descriptor supports B<poll>(2) (and analogously "
375 "B<epoll>(7)) and B<select>(2), as follows:"
379 #: build/C/man2/eventfd.2:167
381 "The file descriptor is readable (the B<select>(2) I<readfds> argument; the "
382 "B<poll>(2) B<POLLIN> flag) if the counter has a value greater than 0."
386 #: build/C/man2/eventfd.2:177
388 "The file descriptor is writable (the B<select>(2) I<writefds> argument; the "
389 "B<poll>(2) B<POLLOUT> flag) if it is possible to write a value of at least "
390 "\"1\" without blocking."
394 #: build/C/man2/eventfd.2:197
396 "If an overflow of the counter value was detected, then B<select>(2) "
397 "indicates the file descriptor as being both readable and writable, and "
398 "B<poll>(2) returns a B<POLLERR> event. As noted above, B<write>(2) can "
399 "never overflow the counter. However an overflow can occur if 2^64 eventfd "
400 "\"signal posts\" were performed by the KAIO subsystem (theoretically "
401 "possible, but practically unlikely). If an overflow has occurred, then "
402 "B<read>(2) will return that maximum I<uint64_t> value (i.e., "
403 "0xffffffffffffffff)."
407 #: build/C/man2/eventfd.2:205
409 "The eventfd file descriptor also supports the other file-descriptor "
410 "multiplexing APIs: B<pselect>(2), B<ppoll>(2), and B<epoll>(7)."
414 #: build/C/man2/eventfd.2:205 build/C/man2/signalfd.2:159 build/C/man2/timerfd_create.2:261
420 #: build/C/man2/eventfd.2:210
422 "When the file descriptor is no longer required it should be closed. When "
423 "all file descriptors associated with the same eventfd object have been "
424 "closed, the resources for object are freed by the kernel."
428 #: build/C/man2/eventfd.2:222
430 "A copy of the file descriptor created by B<eventfd>() is inherited by the "
431 "child produced by B<fork>(2). The duplicate file descriptor is associated "
432 "with the same eventfd object. File descriptors created by B<eventfd>() are "
433 "preserved across B<execve>(2), unless the close-on-exec flag has been set."
437 #: build/C/man2/eventfd.2:229
439 "On success, B<eventfd>() returns a new eventfd file descriptor. On error, "
440 "-1 is returned and I<errno> is set to indicate the error."
444 #: build/C/man2/eventfd.2:230 build/C/man2/getitimer.2:130 build/C/man2/kill.2:105 build/C/man2/killpg.2:94 build/C/man2/prctl.2:537 build/C/man2/prctl.2:542 build/C/man2/prctl.2:554 build/C/man2/prctl.2:559 build/C/man2/prctl.2:568 build/C/man2/rt_sigqueueinfo.2:136 build/C/man2/sigaction.2:666 build/C/man2/sigaltstack.2:140 build/C/man3/siginterrupt.3:77 build/C/man2/signal.2:101 build/C/man2/signalfd.2:268 build/C/man2/signalfd.2:276 build/C/man2/sigprocmask.2:102 build/C/man3/sigqueue.3:96 build/C/man3/sigsetops.3:122 build/C/man3/sigwait.3:72 build/C/man2/sigwaitinfo.2:122 build/C/man2/timer_create.2:177 build/C/man2/timer_delete.2:58 build/C/man2/timer_getoverrun.2:88 build/C/man2/timer_settime.2:187 build/C/man2/timer_settime.2:195 build/C/man2/timerfd_create.2:304 build/C/man2/timerfd_create.2:312 build/C/man2/timerfd_create.2:348 build/C/man2/timerfd_create.2:355 build/C/man2/timerfd_create.2:361 build/C/man2/tkill.2:74 build/C/man2/wait.2:416
450 #: build/C/man2/eventfd.2:234
451 msgid "An unsupported value was specified in I<flags>."
455 #: build/C/man2/eventfd.2:234 build/C/man2/signalfd.2:283 build/C/man2/timerfd_create.2:319
461 #: build/C/man2/eventfd.2:237
462 msgid "The per-process limit on open file descriptors has been reached."
466 #: build/C/man2/eventfd.2:237 build/C/man2/signalfd.2:286 build/C/man2/timerfd_create.2:322
472 #: build/C/man2/eventfd.2:241 build/C/man2/signalfd.2:290 build/C/man2/timerfd_create.2:326
473 msgid "The system-wide limit on the total number of open files has been reached."
477 #: build/C/man2/eventfd.2:241 build/C/man2/signalfd.2:290 build/C/man2/timerfd_create.2:326
483 #: build/C/man2/eventfd.2:249 build/C/man2/signalfd.2:293 build/C/man2/timerfd_create.2:329
484 msgid "Could not mount (internal) anonymous inode device."
488 #: build/C/man2/eventfd.2:249 build/C/man2/sigaltstack.2:145 build/C/man2/signalfd.2:293 build/C/man2/timer_create.2:185 build/C/man2/timerfd_create.2:329
494 #: build/C/man2/eventfd.2:253
495 msgid "There was insufficient memory to create a new eventfd file descriptor."
499 #: build/C/man2/eventfd.2:253 build/C/man2/prctl.2:689 build/C/man3/psignal.3:93 build/C/man2/rt_sigqueueinfo.2:164 build/C/man2/signalfd.2:296 build/C/man3/sigqueue.3:110 build/C/man2/timer_create.2:189 build/C/man2/timer_delete.2:62 build/C/man2/timer_getoverrun.2:92 build/C/man2/timer_settime.2:201 build/C/man2/timerfd_create.2:367 build/C/man2/tkill.2:85
504 #. eventfd() is in glibc 2.7, but reportedly does not build
506 #: build/C/man2/eventfd.2:266
508 "B<eventfd>() is available on Linux since kernel 2.6.22. Working support is "
509 "provided in glibc since version 2.8. The B<eventfd2>() system call (see "
510 "NOTES) is available on Linux since kernel 2.6.27. Since version 2.9, the "
511 "glibc B<eventfd>() wrapper will employ the B<eventfd2>() system call, if "
512 "it is supported by the kernel."
516 #: build/C/man2/eventfd.2:271
517 msgid "B<eventfd>() and B<eventfd2>() are Linux-specific."
521 #: build/C/man2/eventfd.2:279
523 "Applications can use an eventfd file descriptor instead of a pipe (see "
524 "B<pipe>(2)) in all cases where a pipe is used simply to signal events. The "
525 "kernel overhead of an eventfd file descriptor is much lower than that of a "
526 "pipe, and only one file descriptor is required (versus the two required for "
530 #. or eventually syslets/threadlets
532 #: build/C/man2/eventfd.2:285
534 "When used in the kernel, an eventfd file descriptor can provide a "
535 "kernel-userspace bridge allowing, for example, functionalities like KAIO "
536 "(kernel AIO) to signal to a file descriptor that some operation is "
541 #: build/C/man2/eventfd.2:302
543 "A key point about an eventfd file descriptor is that it can be monitored "
544 "just like any other file descriptor using B<select>(2), B<poll>(2), or "
545 "B<epoll>(7). This means that an application can simultaneously monitor the "
546 "readiness of \"traditional\" files and the readiness of other kernel "
547 "mechanisms that support the eventfd interface. (Without the B<eventfd>() "
548 "interface, these mechanisms could not be multiplexed via B<select>(2), "
549 "B<poll>(2), or B<epoll>(7).)"
553 #: build/C/man2/eventfd.2:302 build/C/man2/signalfd.2:333
555 msgid "Underlying Linux system calls"
559 #: build/C/man2/eventfd.2:316
561 "There are two underlying Linux system calls: B<eventfd>() and the more "
562 "recent B<eventfd2>(). The former system call does not implement a I<flags> "
563 "argument. The latter system call implements the I<flags> values described "
564 "above. The glibc wrapper function will use B<eventfd2>() where it is "
569 #: build/C/man2/eventfd.2:316
571 msgid "Additional glibc features"
575 #: build/C/man2/eventfd.2:320
577 "The GNU C library defines an additional type, and two functions that attempt "
578 "to abstract some of the details of reading and writing on an eventfd file "
583 #: build/C/man2/eventfd.2:324
585 msgid "typedef uint64_t eventfd_t;\n"
589 #: build/C/man2/eventfd.2:327
592 "int eventfd_read(int fd, eventfd_t *value);\n"
593 "int eventfd_write(int fd, eventfd_t value);\n"
597 #: build/C/man2/eventfd.2:334
599 "The functions perform the read and write operations on an eventfd file "
600 "descriptor, returning 0 if the correct number of bytes was transferred, or "
605 #: build/C/man2/eventfd.2:334 build/C/man2/sigaction.2:786 build/C/man2/sigaltstack.2:213 build/C/man2/signalfd.2:357 build/C/man3/sigwait.3:83 build/C/man2/timer_create.2:251 build/C/man2/timer_getoverrun.2:125 build/C/man2/timer_settime.2:205 build/C/man2/timerfd_create.2:372 build/C/man2/wait.2:522
611 #: build/C/man2/eventfd.2:343
613 "The following program creates an eventfd file descriptor and then forks to "
614 "create a child process. While the parent briefly sleeps, the child writes "
615 "each of the integers supplied in the program's command-line arguments to the "
616 "eventfd file descriptor. When the parent has finished sleeping, it reads "
617 "from the eventfd file descriptor."
621 #: build/C/man2/eventfd.2:345
622 msgid "The following shell session shows a sample run of the program:"
626 #: build/C/man2/eventfd.2:357
629 "$B< ./a.out 1 2 4 7 14>\n"
630 "Child writing 1 to efd\n"
631 "Child writing 2 to efd\n"
632 "Child writing 4 to efd\n"
633 "Child writing 7 to efd\n"
634 "Child writing 14 to efd\n"
635 "Child completed write loop\n"
636 "Parent about to read\n"
637 "Parent read 28 (0x1c) from efd\n"
641 #: build/C/man2/eventfd.2:359 build/C/man2/signalfd.2:380 build/C/man2/timerfd_create.2:400 build/C/man2/wait.2:557
643 msgid "Program source"
647 #: build/C/man2/eventfd.2:367
650 "#include E<lt>sys/eventfd.hE<gt>\n"
651 "#include E<lt>unistd.hE<gt>\n"
652 "#include E<lt>stdlib.hE<gt>\n"
653 "#include E<lt>stdio.hE<gt>\n"
654 "#include E<lt>stdint.hE<gt> /* Definition of uint64_t */\n"
658 #: build/C/man2/eventfd.2:370 build/C/man2/signalfd.2:391
661 "#define handle_error(msg) \\e\n"
662 " do { perror(msg); exit(EXIT_FAILURE); } while (0)\n"
666 #: build/C/man2/eventfd.2:377
670 "main(int argc, char *argv[])\n"
678 #: build/C/man2/eventfd.2:382
681 " if (argc E<lt> 2) {\n"
682 " fprintf(stderr, \"Usage: %s E<lt>numE<gt>...\\en\", argv[0]);\n"
683 " exit(EXIT_FAILURE);\n"
688 #: build/C/man2/eventfd.2:386
691 " efd = eventfd(0, 0);\n"
693 " handle_error(\"eventfd\");\n"
697 #: build/C/man2/eventfd.2:398
700 " switch (fork()) {\n"
702 " for (j = 1; j E<lt> argc; j++) {\n"
703 " printf(\"Child writing %s to efd\\en\", argv[j]);\n"
704 " u = strtoull(argv[j], NULL, 0);\n"
705 " /* strtoull() allows various bases */\n"
706 " s = write(efd, &u, sizeof(uint64_t));\n"
707 " if (s != sizeof(uint64_t))\n"
708 " handle_error(\"write\");\n"
710 " printf(\"Child completed write loop\\en\");\n"
714 #: build/C/man2/eventfd.2:400
716 msgid " exit(EXIT_SUCCESS);\n"
720 #: build/C/man2/eventfd.2:403
728 #: build/C/man2/eventfd.2:411
731 " printf(\"Parent about to read\\en\");\n"
732 " s = read(efd, &u, sizeof(uint64_t));\n"
733 " if (s != sizeof(uint64_t))\n"
734 " handle_error(\"read\");\n"
735 " printf(\"Parent read %llu (0x%llx) from efd\\en\",\n"
736 " (unsigned long long) u, (unsigned long long) u);\n"
737 " exit(EXIT_SUCCESS);\n"
741 #: build/C/man2/eventfd.2:416
745 " handle_error(\"fork\");\n"
751 #: build/C/man2/eventfd.2:427
753 "B<futex>(2), B<pipe>(2), B<poll>(2), B<read>(2), B<select>(2), "
754 "B<signalfd>(2), B<timerfd_create>(2), B<write>(2), B<epoll>(7), "
759 #: build/C/man2/getitimer.2:7
765 #: build/C/man2/getitimer.2:10
766 msgid "getitimer, setitimer - get or set value of an interval timer"
770 #: build/C/man2/getitimer.2:13
772 msgid "B<#include E<lt>sys/time.hE<gt>>\n"
776 #: build/C/man2/getitimer.2:15
778 msgid "B<int getitimer(int >I<which>B<, struct itimerval *>I<curr_value>B<);>\n"
782 #: build/C/man2/getitimer.2:18
785 "B<int setitimer(int >I<which>B<, const struct itimerval *>I<new_value>B<,>\n"
786 "B< struct itimerval *>I<old_value>B<);>\n"
790 #: build/C/man2/getitimer.2:24
792 "The system provides each process with three interval timers, each "
793 "decrementing in a distinct time domain. When any timer expires, a signal is "
794 "sent to the process, and the timer (potentially) restarts."
798 #: build/C/man2/getitimer.2:24
800 msgid "B<ITIMER_REAL>"
804 #: build/C/man2/getitimer.2:29
805 msgid "decrements in real time, and delivers B<SIGALRM> upon expiration."
809 #: build/C/man2/getitimer.2:29
811 msgid "B<ITIMER_VIRTUAL>"
815 #: build/C/man2/getitimer.2:34
817 "decrements only when the process is executing, and delivers B<SIGVTALRM> "
822 #: build/C/man2/getitimer.2:34
824 msgid "B<ITIMER_PROF>"
828 #: build/C/man2/getitimer.2:44
830 "decrements both when the process executes and when the system is executing "
831 "on behalf of the process. Coupled with B<ITIMER_VIRTUAL>, this timer is "
832 "usually used to profile the time spent by the application in user and kernel "
833 "space. B<SIGPROF> is delivered upon expiration."
837 #: build/C/man2/getitimer.2:46
838 msgid "Timer values are defined by the following structures:"
842 #: build/C/man2/getitimer.2:54
845 "struct itimerval {\n"
846 " struct timeval it_interval; /* next value */\n"
847 " struct timeval it_value; /* current value */\n"
852 #: build/C/man2/getitimer.2:59
856 " long tv_sec; /* seconds */\n"
857 " long tv_usec; /* microseconds */\n"
862 #: build/C/man2/getitimer.2:81
864 "The function B<getitimer>() fills the structure pointed to by I<curr_value> "
865 "with the current setting for the timer specified by I<which> (one of "
866 "B<ITIMER_REAL>, B<ITIMER_VIRTUAL>, or B<ITIMER_PROF>). The element "
867 "I<it_value> is set to the amount of time remaining on the timer, or zero if "
868 "the timer is disabled. Similarly, I<it_interval> is set to the reset value."
872 #: build/C/man2/getitimer.2:89
874 "The function B<setitimer>() sets the specified timer to the value in "
875 "I<new_value>. If I<old_value> is non-NULL, the old value of the timer is "
880 #: build/C/man2/getitimer.2:99
882 "Timers decrement from I<it_value> to zero, generate a signal, and reset to "
883 "I<it_interval>. A timer which is set to zero (I<it_value> is zero or the "
884 "timer expires and I<it_interval> is zero) stops."
888 #: build/C/man2/getitimer.2:105
890 "Both I<tv_sec> and I<tv_usec> are significant in determining the duration of "
895 #: build/C/man2/getitimer.2:117
897 "Timers will never expire before the requested time, but may expire some "
898 "(short) time afterward, which depends on the system timer resolution and on "
899 "the system load; see B<time>(7). (But see BUGS below.) Upon expiration, a "
900 "signal will be generated and the timer reset. If the timer expires while "
901 "the process is active (always true for B<ITIMER_VIRTUAL>) the signal will "
902 "be delivered immediately when generated. Otherwise the delivery will be "
903 "offset by a small time dependent on the system loading."
907 #: build/C/man2/getitimer.2:122 build/C/man2/killpg.2:93 build/C/man2/tkill.2:73
909 "On success, zero is returned. On error, -1 is returned, and I<errno> is set "
914 #: build/C/man2/getitimer.2:123 build/C/man2/prctl.2:533 build/C/man2/sigaction.2:662 build/C/man2/sigaltstack.2:136 build/C/man2/sigpending.2:55 build/C/man2/sigprocmask.2:95 build/C/man2/sigsuspend.2:73 build/C/man2/timer_settime.2:180 build/C/man2/timerfd_create.2:341
920 #: build/C/man2/getitimer.2:130 build/C/man2/timerfd_create.2:348
921 msgid "I<new_value>, I<old_value>, or I<curr_value> is not valid a pointer."
925 #: build/C/man2/getitimer.2:143
927 "I<which> is not one of B<ITIMER_REAL>, B<ITIMER_VIRTUAL>, or B<ITIMER_PROF>; "
928 "or (since Linux 2.6.22) one of the I<tv_usec> fields in the structure "
929 "pointed to by I<new_value> contains a value outside the range 0 to 999999."
933 #: build/C/man2/getitimer.2:153
935 "POSIX.1-2001, SVr4, 4.4BSD (this call first appeared in 4.2BSD). "
936 "POSIX.1-2008 marks B<getitimer>() and B<setitimer>() obsolete, "
937 "recommending the use of the POSIX timers API (B<timer_gettime>(2), "
938 "B<timer_settime>(2), etc.) instead."
942 #: build/C/man2/getitimer.2:159
944 "A child created via B<fork>(2) does not inherit its parent's interval "
945 "timers. Interval timers are preserved across an B<execve>(2)."
949 #: build/C/man2/getitimer.2:169
951 "POSIX.1 leaves the interaction between B<setitimer>() and the three "
952 "interfaces B<alarm>(2), B<sleep>(3), and B<usleep>(3) unspecified."
956 #: build/C/man2/getitimer.2:169 build/C/man2/kill.2:160 build/C/man3/profil.3:70 build/C/man3/psignal.3:99 build/C/man2/sigaction.2:777 build/C/man7/signal.7:836 build/C/man2/signalfd.2:349 build/C/man2/sigpending.2:76 build/C/man3/sigset.3:230 build/C/man2/timer_getoverrun.2:112 build/C/man2/timerfd_create.2:534
962 #: build/C/man2/getitimer.2:178
964 "The generation and delivery of a signal are distinct, and only one instance "
965 "of each of the signals listed above may be pending for a process. Under "
966 "very heavy loading, an B<ITIMER_REAL> timer may expire before the signal "
967 "from a previous expiration has been delivered. The second signal in such an "
968 "event will be lost."
972 #: build/C/man2/getitimer.2:193
974 "On Linux kernels before 2.6.16, timer values are represented in jiffies. If "
975 "a request is made set a timer with a value whose jiffies representation "
976 "exceeds B<MAX_SEC_IN_JIFFIES> (defined in I<include/linux/jiffies.h>), then "
977 "the timer is silently truncated to this ceiling value. On Linux/i386 "
978 "(where, since Linux 2.6.13, the default jiffy is 0.004 seconds), this means "
979 "that the ceiling value for a timer is approximately 99.42 days. Since Linux "
980 "2.6.16, the kernel uses a different internal representation for times, and "
981 "this ceiling is removed."
984 #. 4 Jul 2005: It looks like this bug may remain in 2.4.x.
985 #. http://lkml.org/lkml/2005/7/1/165
987 #: build/C/man2/getitimer.2:200
989 "On certain systems (including i386), Linux kernels before version 2.6.12 "
990 "have a bug which will produce premature timer expirations of up to one jiffy "
991 "under some circumstances. This bug is fixed in kernel 2.6.12."
994 #. Bugzilla report 25 Apr 2006:
995 #. http://bugzilla.kernel.org/show_bug.cgi?id=6443
996 #. "setitimer() should reject noncanonical arguments"
998 #: build/C/man2/getitimer.2:219
1000 "POSIX.1-2001 says that B<setitimer>() should fail if a I<tv_usec> value is "
1001 "specified that is outside of the range 0 to 999999. However, in kernels up "
1002 "to and including 2.6.21, Linux does not give an error, but instead silently "
1003 "adjusts the corresponding seconds value for the timer. From kernel 2.6.22 "
1004 "onward, this nonconformance has been repaired: an improper I<tv_usec> value "
1005 "results in an B<EINVAL> error."
1009 #: build/C/man2/getitimer.2:225
1011 "B<gettimeofday>(2), B<sigaction>(2), B<signal>(2), B<timer_create>(2), "
1012 "B<timerfd_create>(2), B<time>(7)"
1016 #: build/C/man3/gsignal.3:25
1022 #: build/C/man3/gsignal.3:25 build/C/man3/profil.3:28 build/C/man3/sigvec.3:24
1028 #: build/C/man3/gsignal.3:28
1029 msgid "gsignal, ssignal - software signal facility"
1033 #: build/C/man3/gsignal.3:31 build/C/man2/kill.2:52 build/C/man3/psignal.3:34 build/C/man3/raise.3:33 build/C/man2/sigaction.2:51 build/C/man3/siginterrupt.3:35 build/C/man3/sigpause.3:29 build/C/man3/sigwait.3:30 build/C/man2/sigwaitinfo.2:29
1035 msgid "B<#include E<lt>signal.hE<gt>>\n"
1039 #: build/C/man3/gsignal.3:33
1041 msgid "B<typedef void (*sighandler_t)(int);>\n"
1045 #: build/C/man3/gsignal.3:35
1047 msgid "B<int gsignal(int>I<signum>B<);>\n"
1051 #: build/C/man3/gsignal.3:37
1053 msgid "B<sighandler_t ssignal(int >I<signum>B<, sighandler_t >I<action>B<);>\n"
1057 #: build/C/man3/gsignal.3:42 build/C/man2/kill.2:59 build/C/man2/killpg.2:51 build/C/man3/profil.3:40 build/C/man3/psignal.3:44 build/C/man2/sigaction.2:59 build/C/man2/sigaltstack.2:36 build/C/man3/siginterrupt.3:42 build/C/man2/sigpending.2:38 build/C/man2/sigprocmask.2:39 build/C/man3/sigqueue.3:37 build/C/man3/sigset.3:43 build/C/man3/sigsetops.3:49 build/C/man2/sigsuspend.2:38 build/C/man3/sigvec.3:43 build/C/man3/sigwait.3:37 build/C/man2/sigwaitinfo.2:39 build/C/man2/timer_create.2:46 build/C/man2/timer_delete.2:38 build/C/man2/timer_getoverrun.2:38 build/C/man2/timer_settime.2:42 build/C/man2/wait.2:68 build/C/man2/wait4.2:54
1058 msgid "Feature Test Macro Requirements for glibc (see B<feature_test_macros>(7)):"
1062 #: build/C/man3/gsignal.3:47
1063 msgid "B<gsignal>(), B<ssignal>(): _SVID_SOURCE"
1067 #: build/C/man3/gsignal.3:55
1069 "Don't use these functions under Linux. Due to a historical mistake, under "
1070 "Linux these functions are aliases for B<raise>(3) and B<signal>(2), "
1075 #: build/C/man3/gsignal.3:93
1077 "Elsewhere, on System V-like systems, these functions implement software "
1078 "signaling, entirely independent of the classical B<signal>(2) and "
1079 "B<kill>(2) functions. The function B<ssignal>() defines the action to "
1080 "take when the software signal with number I<signum> is raised using the "
1081 "function B<gsignal>(), and returns the previous such action or B<SIG_DFL>. "
1082 "The function B<gsignal>() does the following: if no action (or the action "
1083 "B<SIG_DFL>) was specified for I<signum>, then it does nothing and returns "
1084 "0. If the action B<SIG_IGN> was specified for I<signum>, then it does "
1085 "nothing and returns 1. Otherwise, it resets the action to B<SIG_DFL> and "
1086 "calls the action function with argument I<signum>, and returns the value "
1087 "returned by that function. The range of possible values I<signum> varies "
1088 "(often 1-15 or 1-17)."
1092 #: build/C/man3/gsignal.3:101
1094 "These functions are available under AIX, DG/UX, HP-UX, SCO, Solaris, Tru64. "
1095 "They are called obsolete under most of these systems, and are broken under "
1096 "Linux libc and glibc. Some systems also have B<gsignal_r>() and "
1101 #: build/C/man3/gsignal.3:104
1102 msgid "B<kill>(2), B<signal>(2), B<raise>(3)"
1106 #: build/C/man2/kill.2:44
1112 #: build/C/man2/kill.2:44
1118 #: build/C/man2/kill.2:47
1119 msgid "kill - send signal to a process"
1123 #: build/C/man2/kill.2:50
1125 msgid "B<#include E<lt>sys/types.hE<gt>>\n"
1129 #: build/C/man2/kill.2:54
1131 msgid "B<int kill(pid_t >I<pid>B<, int >I<sig>B<);>\n"
1135 #: build/C/man2/kill.2:64
1136 msgid "B<kill>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE"
1140 #: build/C/man2/kill.2:70
1142 "The B<kill>() system call can be used to send any signal to any process "
1147 #: build/C/man2/kill.2:73
1149 "If I<pid> is positive, then signal I<sig> is sent to the process with the ID "
1150 "specified by I<pid>."
1154 #: build/C/man2/kill.2:76
1156 "If I<pid> equals 0, then I<sig> is sent to every process in the process "
1157 "group of the calling process."
1161 #: build/C/man2/kill.2:80
1163 "If I<pid> equals -1, then I<sig> is sent to every process for which the "
1164 "calling process has permission to send signals, except for process 1 "
1165 "(I<init>), but see below."
1169 #: build/C/man2/kill.2:83
1171 "If I<pid> is less than -1, then I<sig> is sent to every process in the "
1172 "process group whose ID is I<-pid>."
1176 #: build/C/man2/kill.2:88
1178 "If I<sig> is 0, then no signal is sent, but error checking is still "
1179 "performed; this can be used to check for the existence of a process ID or "
1184 #: build/C/man2/kill.2:99 build/C/man2/killpg.2:88
1186 "For a process to have permission to send a signal it must either be "
1187 "privileged (under Linux: have the B<CAP_KILL> capability), or the real or "
1188 "effective user ID of the sending process must equal the real or saved "
1189 "set-user-ID of the target process. In the case of B<SIGCONT> it suffices "
1190 "when the sending and receiving processes belong to the same session."
1194 #: build/C/man2/kill.2:104
1196 "On success (at least one signal was sent), zero is returned. On error, -1 "
1197 "is returned, and I<errno> is set appropriately."
1201 #: build/C/man2/kill.2:108
1202 msgid "An invalid signal was specified."
1206 #: build/C/man2/kill.2:108 build/C/man2/killpg.2:98 build/C/man2/prctl.2:608 build/C/man2/prctl.2:620 build/C/man2/prctl.2:630 build/C/man2/prctl.2:638 build/C/man2/rt_sigqueueinfo.2:143 build/C/man2/sigaltstack.2:149 build/C/man3/sigqueue.3:100 build/C/man2/tkill.2:77
1212 #: build/C/man2/kill.2:112 build/C/man2/killpg.2:102
1214 "The process does not have permission to send the signal to any of the target "
1219 #: build/C/man2/kill.2:112 build/C/man2/killpg.2:102 build/C/man2/killpg.2:106 build/C/man2/rt_sigqueueinfo.2:151 build/C/man3/sigqueue.3:106 build/C/man2/tkill.2:82
1225 #: build/C/man2/kill.2:120
1227 "The pid or process group does not exist. Note that an existing process "
1228 "might be a zombie, a process which already committed termination, but has "
1229 "not yet been B<wait>(2)ed for."
1233 #: build/C/man2/kill.2:122 build/C/man2/pause.2:59 build/C/man2/wait.2:423
1234 msgid "SVr4, 4.3BSD, POSIX.1-2001."
1238 #: build/C/man2/kill.2:130
1240 "The only signals that can be sent to process ID 1, the I<init> process, are "
1241 "those for which I<init> has explicitly installed signal handlers. This is "
1242 "done to assure the system is not brought down accidentally."
1246 #: build/C/man2/kill.2:136
1248 "POSIX.1-2001 requires that I<kill(-1,sig)> send I<sig> to all processes that "
1249 "the calling process may send signals to, except possibly for some "
1250 "implementation-defined system processes. Linux allows a process to signal "
1251 "itself, but on Linux the call I<kill(-1,sig)> does not signal the calling "
1256 #: build/C/man2/kill.2:146
1258 "POSIX.1-2001 requires that if a process sends a signal to itself, and the "
1259 "sending thread does not have the signal blocked, and no other thread has it "
1260 "unblocked or is waiting for it in B<sigwait>(3), at least one unblocked "
1261 "signal must be delivered to the sending thread before the B<kill>() "
1266 #: build/C/man2/kill.2:146 build/C/man3/sigpause.3:75 build/C/man2/wait.2:477
1271 #. In the 0.* kernels things chopped and changed quite
1272 #. a bit - MTK, 24 Jul 02
1274 #: build/C/man2/kill.2:160
1276 "Across different kernel versions, Linux has enforced different rules for the "
1277 "permissions required for an unprivileged process to send a signal to another "
1278 "process. In kernels 1.0 to 1.2.2, a signal could be sent if the effective "
1279 "user ID of the sender matched that of the receiver, or the real user ID of "
1280 "the sender matched that of the receiver. From kernel 1.2.3 until 1.3.77, a "
1281 "signal could be sent if the effective user ID of the sender matched either "
1282 "the real or effective user ID of the receiver. The current rules, which "
1283 "conform to POSIX.1-2001, were adopted in kernel 1.3.78."
1287 #: build/C/man2/kill.2:170
1289 "In 2.6 kernels up to and including 2.6.7, there was a bug that meant that "
1290 "when sending signals to a process group, B<kill>() failed with the error "
1291 "B<EPERM> if the caller did have permission to send the signal to I<any> "
1292 "(rather than I<all>) of the members of the process group. Notwithstanding "
1293 "this error return, the signal was still delivered to all of the processes "
1294 "for which the caller had permission to signal."
1298 #: build/C/man2/kill.2:179
1300 "B<_exit>(2), B<killpg>(2), B<signal>(2), B<tkill>(2), B<exit>(3), "
1301 "B<sigqueue>(3), B<capabilities>(7), B<credentials>(7), B<signal>(7)"
1305 #: build/C/man2/killpg.2:40
1311 #: build/C/man2/killpg.2:40 build/C/man3/sigset.3:24 build/C/man2/wait4.2:34
1317 #: build/C/man2/killpg.2:43
1318 msgid "killpg - send signal to a process group"
1322 #: build/C/man2/killpg.2:47
1323 msgid "B<int killpg(int >I<pgrp>B<, int >I<sig>B<);>"
1327 #: build/C/man2/killpg.2:54
1329 msgid "B<killpg>():"
1333 #: build/C/man2/killpg.2:58 build/C/man2/sigaltstack.2:44 build/C/man3/siginterrupt.3:49 build/C/man2/wait4.2:61
1335 "_BSD_SOURCE || _XOPEN_SOURCE\\ E<gt>=\\ 500 || _XOPEN_SOURCE\\ &&\\ "
1336 "_XOPEN_SOURCE_EXTENDED"
1340 #: build/C/man2/killpg.2:68
1342 "B<killpg>() sends the signal I<sig> to the process group I<pgrp>. See "
1343 "B<signal>(7) for a list of signals."
1347 #: build/C/man2/killpg.2:77
1349 "If I<pgrp> is 0, B<killpg>() sends the signal to the calling process's "
1350 "process group. (POSIX says: If I<pgrp> is less than or equal to 1, the "
1351 "behavior is undefined.)"
1355 #: build/C/man2/killpg.2:98
1356 msgid "I<Sig> is not a valid signal number."
1360 #: build/C/man2/killpg.2:106
1361 msgid "No process can be found in the process group specified by I<pgrp>."
1365 #: build/C/man2/killpg.2:110
1367 "The process group was given as 0 but the sending process does not have a "
1372 #: build/C/man2/killpg.2:114
1374 "SVr4, 4.4BSD (the B<killpg>() function call first appeared in 4BSD), "
1379 #: build/C/man2/killpg.2:128
1381 "There are various differences between the permission checking in BSD-type "
1382 "systems and System V-type systems. See the POSIX rationale for B<kill>(). "
1383 "A difference not mentioned by POSIX concerns the return value B<EPERM>: BSD "
1384 "documents that no signal is sent and B<EPERM> returned when the permission "
1385 "check failed for at least one target process, while POSIX documents B<EPERM> "
1386 "only when the permission check failed for all target processes."
1390 #: build/C/man2/killpg.2:133
1392 "On Linux, B<killpg>() is implemented as a library function that makes the "
1393 "call I<kill(-pgrp,\\ sig)>."
1397 #: build/C/man2/killpg.2:138
1399 "B<getpgrp>(2), B<kill>(2), B<signal>(2), B<capabilities>(7), "
1404 #: build/C/man2/pause.2:30
1410 #: build/C/man2/pause.2:30
1416 #: build/C/man2/pause.2:33
1417 msgid "pause - wait for signal"
1421 #: build/C/man2/pause.2:35 build/C/man3/profil.3:33
1422 msgid "B<#include E<lt>unistd.hE<gt>>"
1426 #: build/C/man2/pause.2:37
1427 msgid "B<int pause(void);>"
1431 #: build/C/man2/pause.2:42
1433 "B<pause>() causes the calling process (or thread) to sleep until a signal "
1434 "is delivered that either terminates the process or causes the invocation of "
1435 "a signal-catching function."
1438 #. .BR ERESTARTNOHAND .
1440 #: build/C/man2/pause.2:53
1442 "B<pause>() only returns when a signal was caught and the signal-catching "
1443 "function returned. In this case B<pause>() returns -1, and I<errno> is set "
1448 #: build/C/man2/pause.2:54 build/C/man2/sigsuspend.2:77 build/C/man2/sigwaitinfo.2:116 build/C/man2/wait.2:409
1454 #: build/C/man2/pause.2:57
1455 msgid "a signal was caught and the signal-catching function returned."
1459 #: build/C/man2/pause.2:63
1460 msgid "B<kill>(2), B<select>(2), B<signal>(2), B<sigsuspend>(2)"
1464 #: build/C/man2/prctl.2:46
1470 #: build/C/man2/prctl.2:46
1476 #: build/C/man2/prctl.2:49
1477 msgid "prctl - operations on a process"
1481 #: build/C/man2/prctl.2:52
1483 msgid "B<#include E<lt>sys/prctl.hE<gt>>\n"
1487 #: build/C/man2/prctl.2:55
1490 "B<int prctl(int >I<option>B<, unsigned long >I<arg2>B<, unsigned long "
1492 "B< unsigned long >I<arg4>B<, unsigned long >I<arg5>B<);>\n"
1496 #: build/C/man2/prctl.2:62
1498 "B<prctl>() is called with a first argument describing what to do (with "
1499 "values defined in I<E<lt>linux/prctl.hE<gt>>), and further arguments with a "
1500 "significance depending on the first one. The first argument can be:"
1504 #: build/C/man2/prctl.2:62
1506 msgid "B<PR_CAPBSET_READ> (since Linux 2.6.25)"
1510 #: build/C/man2/prctl.2:74
1512 "Return (as the function result) 1 if the capability specified in I<arg2> is "
1513 "in the calling thread's capability bounding set, or 0 if it is not. (The "
1514 "capability constants are defined in I<E<lt>linux/capability.hE<gt>>.) The "
1515 "capability bounding set dictates whether the process can receive the "
1516 "capability through a file's permitted capability set on a subsequent call to "
1521 #: build/C/man2/prctl.2:79
1523 "If the capability specified in I<arg2> is not valid, then the call fails "
1524 "with the error B<EINVAL>."
1528 #: build/C/man2/prctl.2:79
1530 msgid "B<PR_CAPBSET_DROP> (since Linux 2.6.25)"
1534 #: build/C/man2/prctl.2:88
1536 "If the calling thread has the B<CAP_SETPCAP> capability, then drop the "
1537 "capability specified by I<arg2> from the calling thread's capability "
1538 "bounding set. Any children of the calling thread will inherit the newly "
1539 "reduced bounding set."
1543 #: build/C/man2/prctl.2:100
1545 "The call fails with the error: B<EPERM> if the calling thread does not have "
1546 "the B<CAP_SETPCAP>; B<EINVAL> if I<arg2> does not represent a valid "
1547 "capability; or B<EINVAL> if file capabilities are not enabled in the kernel, "
1548 "in which case bounding sets are not supported."
1552 #: build/C/man2/prctl.2:100
1554 msgid "B<PR_SET_DUMPABLE> (since Linux 2.3.20)"
1557 #. See http://marc.theaimsgroup.com/?l=linux-kernel&m=115270289030630&w=2
1558 #. Subject: Fix prctl privilege escalation (CVE-2006-2451)
1559 #. From: Marcel Holtmann <marcel () holtmann ! org>
1560 #. Date: 2006-07-12 11:12:00
1562 #: build/C/man2/prctl.2:126
1564 "Set the state of the flag determining whether core dumps are produced for "
1565 "this process upon delivery of a signal whose default behavior is to produce "
1566 "a core dump. (Normally this flag is set for a process by default, but it is "
1567 "cleared when a set-user-ID or set-group-ID program is executed and also by "
1568 "various system calls that manipulate process UIDs and GIDs). In kernels up "
1569 "to and including 2.6.12, I<arg2> must be either 0 (process is not dumpable) "
1570 "or 1 (process is dumpable). Between kernels 2.6.13 and 2.6.17, the value 2 "
1571 "was also permitted, which caused any binary which normally would not be "
1572 "dumped to be dumped readable by root only; for security reasons, this "
1573 "feature has been removed. (See also the description of "
1574 "I</proc/sys/fs/suid_dumpable> in B<proc>(5).) Processes that are not "
1575 "dumpable can not be attached via B<ptrace(2)> B<PTRACE_ATTACH>."
1579 #: build/C/man2/prctl.2:126
1581 msgid "B<PR_GET_DUMPABLE> (since Linux 2.3.20)"
1584 #. Since Linux 2.6.13, the dumpable flag can have the value 2,
1585 #. but in 2.6.13 PR_GET_DUMPABLE simply returns 1 if the dumpable
1586 #. flags has a nonzero value. This was fixed in 2.6.14.
1588 #: build/C/man2/prctl.2:133
1590 "Return (as the function result) the current state of the calling process's "
1595 #: build/C/man2/prctl.2:133
1597 msgid "B<PR_SET_ENDIAN> (since Linux 2.6.18, PowerPC only)"
1600 #. Respectively 0, 1, 2
1602 #: build/C/man2/prctl.2:143
1604 "Set the endian-ness of the calling process to the value given in I<arg2>, "
1605 "which should be one of the following: B<PR_ENDIAN_BIG>, B<PR_ENDIAN_LITTLE>, "
1606 "or B<PR_ENDIAN_PPC_LITTLE> (PowerPC pseudo little endian)."
1610 #: build/C/man2/prctl.2:143
1612 msgid "B<PR_GET_ENDIAN> (since Linux 2.6.18, PowerPC only)"
1616 #: build/C/man2/prctl.2:148
1618 "Return the endian-ness of the calling process, in the location pointed to by "
1619 "I<(int\\ *) arg2>."
1623 #: build/C/man2/prctl.2:148
1625 msgid "B<PR_SET_FPEMU> (since Linux 2.4.18, 2.5.9, only on ia64)"
1629 #: build/C/man2/prctl.2:155
1631 "Set floating-point emulation control bits to I<arg2>. Pass "
1632 "B<PR_FPEMU_NOPRINT> to silently emulate fp operations accesses, or "
1633 "B<PR_FPEMU_SIGFPE> to not emulate fp operations and send B<SIGFPE> instead."
1637 #: build/C/man2/prctl.2:155
1639 msgid "B<PR_GET_FPEMU> (since Linux 2.4.18, 2.5.9, only on ia64)"
1643 #: build/C/man2/prctl.2:160
1645 "Return floating-point emulation control bits, in the location pointed to by "
1646 "I<(int\\ *) arg2>."
1650 #: build/C/man2/prctl.2:160
1652 msgid "B<PR_SET_FPEXC> (since Linux 2.4.21, 2.5.32, only on PowerPC)"
1656 #: build/C/man2/prctl.2:173
1658 "Set floating-point exception mode to I<arg2>. Pass B<PR_FP_EXC_SW_ENABLE> "
1659 "to use FPEXC for FP exception enables, B<PR_FP_EXC_DIV> for floating-point "
1660 "divide by zero, B<PR_FP_EXC_OVF> for floating-point overflow, "
1661 "B<PR_FP_EXC_UND> for floating-point underflow, B<PR_FP_EXC_RES> for "
1662 "floating-point inexact result, B<PR_FP_EXC_INV> for floating-point invalid "
1663 "operation, B<PR_FP_EXC_DISABLED> for FP exceptions disabled, "
1664 "B<PR_FP_EXC_NONRECOV> for async nonrecoverable exception mode, "
1665 "B<PR_FP_EXC_ASYNC> for async recoverable exception mode, "
1666 "B<PR_FP_EXC_PRECISE> for precise exception mode."
1670 #: build/C/man2/prctl.2:173
1672 msgid "B<PR_GET_FPEXC> (since Linux 2.4.21, 2.5.32, only on PowerPC)"
1676 #: build/C/man2/prctl.2:178
1678 "Return floating-point exception mode, in the location pointed to by I<(int\\ "
1683 #: build/C/man2/prctl.2:178
1685 msgid "B<PR_SET_KEEPCAPS> (since Linux 2.2.18)"
1689 #: build/C/man2/prctl.2:196
1691 "Set the state of the thread's \"keep capabilities\" flag, which determines "
1692 "whether the threads's permitted capability set is cleared when a change is "
1693 "made to the threads's user IDs such that the threads's real UID, effective "
1694 "UID, and saved set-user-ID all become nonzero when at least one of them "
1695 "previously had the value 0. By default, the permitted capability set is "
1696 "cleared when such a change is made; setting the \"keep capabilities\" flag "
1697 "prevents it from being cleared. I<arg2> must be either 0 (permitted "
1698 "capabilities are cleared) or 1 (permitted capabilities are kept). (A "
1699 "thread's I<effective> capability set is always cleared when such a "
1700 "credential change is made, regardless of the setting of the \"keep "
1701 "capabilities\" flag.) The \"keep capabilities\" value will be reset to 0 on "
1702 "subsequent calls to B<execve>(2)."
1706 #: build/C/man2/prctl.2:196
1708 msgid "B<PR_GET_KEEPCAPS> (since Linux 2.2.18)"
1712 #: build/C/man2/prctl.2:200
1714 "Return (as the function result) the current state of the calling threads's "
1715 "\"keep capabilities\" flag."
1719 #: build/C/man2/prctl.2:200
1721 msgid "B<PR_SET_NAME> (since Linux 2.6.9)"
1724 #. TASK_COMM_LEN in include/linux/sched.h
1726 #: build/C/man2/prctl.2:208
1728 "Set the process name for the calling process, using the value in the "
1729 "location pointed to by I<(char\\ *) arg2>. The name can be up to 16 bytes "
1730 "long, and should be null-terminated if it contains fewer bytes."
1734 #: build/C/man2/prctl.2:208
1736 msgid "B<PR_GET_NAME> (since Linux 2.6.11)"
1740 #: build/C/man2/prctl.2:215
1742 "Return the process name for the calling process, in the buffer pointed to by "
1743 "I<(char\\ *) arg2>. The buffer should allow space for up to 16 bytes; the "
1744 "returned string will be null-terminated if it is shorter than that."
1748 #: build/C/man2/prctl.2:215
1750 msgid "B<PR_SET_PDEATHSIG> (since Linux 2.1.57)"
1754 #: build/C/man2/prctl.2:224
1756 "Set the parent process death signal of the calling process to I<arg2> "
1757 "(either a signal value in the range 1..maxsig, or 0 to clear). This is the "
1758 "signal that the calling process will get when its parent dies. This value "
1759 "is cleared for the child of a B<fork>(2)."
1763 #: build/C/man2/prctl.2:224
1765 msgid "B<PR_GET_PDEATHSIG> (since Linux 2.3.15)"
1769 #: build/C/man2/prctl.2:229
1771 "Return the current value of the parent process death signal, in the location "
1772 "pointed to by I<(int\\ *) arg2>."
1776 #: build/C/man2/prctl.2:229
1778 msgid "B<PR_SET_SECCOMP> (since Linux 2.6.23)"
1781 #. See http://thread.gmane.org/gmane.linux.kernel/542632
1782 #. [PATCH 0 of 2] seccomp updates
1783 #. andrea@cpushare.com
1785 #: build/C/man2/prctl.2:253
1787 "Set the secure computing mode for the calling thread. In the current "
1788 "implementation, I<arg2> must be 1. After the secure computing mode has been "
1789 "set to 1, the only system calls that the thread is permitted to make are "
1790 "B<read>(2), B<write>(2), B<_exit>(2), and B<sigreturn>(2). Other system "
1791 "calls result in the delivery of a B<SIGKILL> signal. Secure computing mode "
1792 "is useful for number-crunching applications that may need to execute "
1793 "untrusted byte code, perhaps obtained by reading from a pipe or socket. "
1794 "This operation is only available if the kernel is configured with "
1795 "CONFIG_SECCOMP enabled."
1799 #: build/C/man2/prctl.2:253
1801 msgid "B<PR_GET_SECCOMP> (since Linux 2.6.23)"
1805 #: build/C/man2/prctl.2:266
1807 "Return the secure computing mode of the calling thread. Not very useful for "
1808 "the current implementation (mode equals 1), but may be useful for other "
1809 "possible future modes: if the caller is not in secure computing mode, this "
1810 "operation returns 0; if the caller is in secure computing mode, then the "
1811 "B<prctl>() call will cause a B<SIGKILL> signal to be sent to the process. "
1812 "This operation is only available if the kernel is configured with "
1813 "CONFIG_SECCOMP enabled."
1817 #: build/C/man2/prctl.2:266
1819 msgid "B<PR_SET_SECUREBITS> (since Linux 2.6.26)"
1823 #: build/C/man2/prctl.2:272
1825 "Set the \"securebits\" flags of the calling thread to the value supplied in "
1826 "I<arg2>. See B<capabilities>(7)."
1830 #: build/C/man2/prctl.2:272
1832 msgid "B<PR_GET_SECUREBITS> (since Linux 2.6.26)"
1836 #: build/C/man2/prctl.2:278
1838 "Return (as the function result) the \"securebits\" flags of the calling "
1839 "thread. See B<capabilities>(7)."
1843 #: build/C/man2/prctl.2:278
1845 msgid "B<PR_SET_TIMING> (since Linux 2.6.0-test4)"
1850 #. PR_TIMING_TIMESTAMP doesn't do anything in 2.6.26-rc8,
1851 #. and looking at the patch history, it appears
1852 #. that it never did anything.
1854 #: build/C/man2/prctl.2:295
1856 "Set whether to use (normal, traditional) statistical process timing or "
1857 "accurate timestamp-based process timing, by passing B<PR_TIMING_STATISTICAL> "
1858 "or B<PR_TIMING_TIMESTAMP> to I<arg2>. B<PR_TIMING_TIMESTAMP> is not "
1859 "currently implemented (attempting to set this mode will yield the error "
1864 #: build/C/man2/prctl.2:295
1866 msgid "B<PR_GET_TIMING> (since Linux 2.6.0-test4)"
1870 #: build/C/man2/prctl.2:299
1872 "Return (as the function result) which process timing method is currently in "
1877 #: build/C/man2/prctl.2:299
1879 msgid "B<PR_SET_TSC> (since Linux 2.6.26, x86 only)"
1883 #: build/C/man2/prctl.2:312
1885 "Set the state of the flag determining whether the timestamp counter can be "
1886 "read by the process. Pass B<PR_TSC_ENABLE> to I<arg2> to allow it to be "
1887 "read, or B<PR_TSC_SIGSEGV> to generate a B<SIGSEGV> when the process tries "
1888 "to read the timestamp counter."
1892 #: build/C/man2/prctl.2:312
1894 msgid "B<PR_GET_TSC> (since Linux 2.6.26, x86 only)"
1898 #: build/C/man2/prctl.2:318
1900 "Return the state of the flag determining whether the timestamp counter can "
1901 "be read, in the location pointed to by I<(int\\ *) arg2>."
1905 #: build/C/man2/prctl.2:318
1907 msgid "B<PR_SET_UNALIGN>"
1911 #: build/C/man2/prctl.2:328
1913 "(Only on: ia64, since Linux 2.3.48; parisc, since Linux 2.6.15; PowerPC, "
1914 "since Linux 2.6.18; Alpha, since Linux 2.6.22) Set unaligned access control "
1915 "bits to I<arg2>. Pass B<PR_UNALIGN_NOPRINT> to silently fix up unaligned "
1916 "user accesses, or B<PR_UNALIGN_SIGBUS> to generate B<SIGBUS> on unaligned "
1921 #: build/C/man2/prctl.2:328
1923 msgid "B<PR_GET_UNALIGN>"
1927 #: build/C/man2/prctl.2:335
1929 "(see B<PR_SET_UNALIGN> for information on versions and architectures) "
1930 "Return unaligned access control bits, in the location pointed to by I<(int\\ "
1935 #: build/C/man2/prctl.2:335
1937 msgid "B<PR_MCE_KILL> (since Linux 2.6.32)"
1941 #: build/C/man2/prctl.2:375
1943 "Set the machine check memory corruption kill policy for the current thread. "
1944 "If I<arg2> is B<PR_MCE_KILL_CLEAR>, clear the thread memory corruption kill "
1945 "policy and use the system-wide default. (The system-wide default is defined "
1946 "by I</proc/sys/vm/memory_failure_early_kill>; see B<proc>(5).) If I<arg2> "
1947 "is B<PR_MCE_KILL_SET>, use a thread-specific memory corruption kill policy. "
1948 "In this case, I<arg3> defines whether the policy is I<early kill> "
1949 "(B<PR_MCE_KILL_EARLY>), I<late kill> (B<PR_MCE_KILL_LATE>), or the "
1950 "system-wide default (B<PR_MCE_KILL_DEFAULT>). Early kill means that the "
1951 "thread receives a B<SIGBUS> signal as soon as hardware memory corruption is "
1952 "detected inside its address space. In late kill mode, the process is only "
1953 "killed when it accesses a corrupted page. See B<sigaction>(2) for more "
1954 "information on the B<SIGBUS> signal. The policy is inherited by children. "
1955 "The remaining unused B<prctl>() arguments must be zero for future "
1960 #: build/C/man2/prctl.2:375
1962 msgid "B<PR_MCE_KILL_GET> (since Linux 2.6.32)"
1966 #: build/C/man2/prctl.2:381
1968 "Return the current per-process machine check kill policy. All unused "
1969 "B<prctl>() arguments must be zero."
1973 #: build/C/man2/prctl.2:381
1975 msgid "B<PR_SET_MM> (since Linux 3.3)"
1979 #: build/C/man2/prctl.2:401
1981 "Modify certain kernel memory map descriptor fields of the calling process. "
1982 "Usually these fields are set by the kernel and dynamic loader (see "
1983 "B<ld.so>(8) for more information) and a regular application should not use "
1984 "this feature. However, there are cases, such as self-modifying programs, "
1985 "where a program might find it useful to change its own memory map. This "
1986 "feature is available only if the kernel is built with the "
1987 "B<CONFIG_CHECKPOINT_RESTORE> option enabled. The calling process must have "
1988 "the B<CAP_SYS_RESOURCE> capability. The value in I<arg2> is one of the "
1989 "options below, while I<arg3> provides a new value for the option."
1993 #: build/C/man2/prctl.2:402
1995 msgid "B<PR_SET_MM_START_CODE>"
1999 #: build/C/man2/prctl.2:411
2001 "Set the address above which the program text can run. The corresponding "
2002 "memory area must be readable and executable, but not writable or sharable "
2003 "(see B<mprotect>(2) and B<mmap>(2) for more information)."
2007 #: build/C/man2/prctl.2:411
2009 msgid "B<PR_SET_MM_END_CODE>"
2013 #: build/C/man2/prctl.2:416
2015 "Set the address below which the program text can run. The corresponding "
2016 "memory area must be readable and executable, but not writable or sharable."
2020 #: build/C/man2/prctl.2:416
2022 msgid "B<PR_SET_MM_START_DATA>"
2026 #: build/C/man2/prctl.2:422
2028 "Set the address above which initialized and uninitialized (bss) data are "
2029 "placed. The corresponding memory area must be readable and writable, but "
2030 "not executable or sharable."
2034 #: build/C/man2/prctl.2:422
2036 msgid "B<PR_SET_MM_END_DATA>"
2040 #: build/C/man2/prctl.2:428
2042 "Set the address below which initialized and uninitialized (bss) data are "
2043 "placed. The corresponding memory area must be readable and writable, but "
2044 "not executable or sharable."
2048 #: build/C/man2/prctl.2:428
2050 msgid "B<PR_SET_MM_START_STACK>"
2054 #: build/C/man2/prctl.2:432
2056 "Set the start address of the stack. The corresponding memory area must be "
2057 "readable and writable."
2061 #: build/C/man2/prctl.2:432
2063 msgid "B<PR_SET_MM_START_BRK>"
2067 #: build/C/man2/prctl.2:444
2069 "Set the address above which the program heap can be expanded with B<brk>(2) "
2070 "call. The address must be greater than the ending address of the current "
2071 "program data segment. In addition, the combined size of the resulting heap "
2072 "and the size of the data segment can't exceed the B<RLIMIT_DATA> resource "
2073 "limit (see B<setrlimit>(2))."
2077 #: build/C/man2/prctl.2:444
2079 msgid "B<PR_SET_MM_BRK>"
2082 #. FIXME The following (until ========) is not yet in mainline kernel,
2083 #. so commented out for the moment.
2085 #. .BR PR_SET_MM_ARG_START
2086 #. Set the address above which the program command line is placed.
2088 #. .BR PR_SET_MM_ARG_END
2089 #. Set the address below which the program command line is placed.
2091 #. .BR PR_SET_MM_ENV_START
2092 #. Set the address above which the program environment is placed.
2094 #. .BR PR_SET_MM_ENV_END
2095 #. Set the address below which the program environment is placed.
2097 #. The address passed with
2098 #. .BR PR_SET_MM_ARG_START ,
2099 #. .BR PR_SET_MM_ARG_END ,
2100 #. .BR PR_SET_MM_ENV_START ,
2102 #. .BR PR_SET_MM_ENV_END
2103 #. should belong to a process stack area.
2104 #. Thus, the corresponding memory area must be readable, writable, and
2105 #. (depending on the kernel configuration) have the
2106 #. .BR MAP_GROWSDOWN
2107 #. attribute set (see
2110 #. .BR PR_SET_MM_AUXV
2111 #. Set a new auxiliary vector.
2114 #. argument should provide the address of the vector.
2117 #. is the size of the vector.
2119 #. .BR PR_SET_MM_EXE_FILE
2121 #. .IR /proc/pid/exe
2122 #. symbolic link with a new one pointing to a new executable file
2123 #. identified by the file descriptor provided in
2126 #. The file descriptor should be obtained with a regular
2130 #. To change the symbolic link, one needs to unmap all existing
2131 #. executable memory areas, including those created by the kernel itself
2132 #. (for example the kernel usually creates at least one executable
2133 #. memory area for the ELF
2137 #. The second limitation is that such transitions can be done only once
2138 #. in a process life time.
2139 #. Any further attempts will be rejected.
2140 #. This should help system administrators to monitor unusual
2141 #. symbolic-link transitions over all process running in a system.
2142 #. ========== END FIXME
2144 #: build/C/man2/prctl.2:513
2146 "Set the current B<brk>(2) value. The requirements for the address are the "
2147 "same as for the B<PR_SET_MM_START_BRK> option."
2151 #: build/C/man2/prctl.2:532
2153 "On success, B<PR_GET_DUMPABLE>, B<PR_GET_KEEPCAPS>, B<PR_CAPBSET_READ>, "
2154 "B<PR_GET_TIMING>, B<PR_GET_SECUREBITS>, B<PR_MCE_KILL_GET>, and (if it "
2155 "returns) B<PR_GET_SECCOMP> return the nonnegative values described above. "
2156 "All other I<option> values return 0 on success. On error, -1 is returned, "
2157 "and I<errno> is set appropriately."
2161 #: build/C/man2/prctl.2:537
2162 msgid "I<arg2> is an invalid address."
2166 #: build/C/man2/prctl.2:542
2167 msgid "The value of I<option> is not recognized."
2171 #: build/C/man2/prctl.2:554
2173 "I<option> is B<PR_MCE_KILL> or B<PR_MCE_KILL_GET> or B<PR_SET_MM>, and "
2174 "unused B<prctl>() arguments were not specified as zero."
2178 #: build/C/man2/prctl.2:559
2179 msgid "I<arg2> is not valid value for this I<option>."
2183 #: build/C/man2/prctl.2:568
2185 "I<option> is B<PR_SET_SECCOMP> or B<PR_SET_SECCOMP>, and the kernel was not "
2186 "configured with B<CONFIG_SECCOMP>."
2190 #: build/C/man2/prctl.2:574
2191 msgid "I<option> is B<PR_SET_MM>, and one of the following is true"
2195 #: build/C/man2/prctl.2:580
2196 msgid "I<arg4> or I<arg5> is nonzero;"
2200 #: build/C/man2/prctl.2:585
2202 "I<arg3> is greater than B<TASK_SIZE> (the limit on the size of the user "
2203 "address space for this architecture);"
2207 #: build/C/man2/prctl.2:595
2209 "I<arg2> is B<PR_SET_MM_START_CODE>, B<PR_SET_MM_END_CODE>, "
2210 "B<PR_SET_MM_START_DATA>, B<PR_SET_MM_END_DATA>, or B<PR_SET_MM_START_STACK,> "
2211 "and the permissions of the corresponding memory area are not as required;"
2215 #: build/C/man2/prctl.2:607
2217 "I<arg2> is B<PR_SET_MM_START_BRK> or B<PR_SET_MM_BRK>, and I<arg3> is less "
2218 "than or equal to the end of the data segment or specifies a value that would "
2219 "cause the B<RLIMIT_DATA> resource limit to be exceeded."
2223 #: build/C/man2/prctl.2:620
2225 "I<option> is B<PR_SET_SECUREBITS>, and the caller does not have the "
2226 "B<CAP_SETPCAP> capability, or tried to unset a \"locked\" flag, or tried to "
2227 "set a flag whose corresponding locked flag was set (see B<capabilities>(7))."
2231 #: build/C/man2/prctl.2:630
2233 "I<option> is B<PR_SET_KEEPCAPS>, and the callers's "
2234 "B<SECURE_KEEP_CAPS_LOCKED> flag is set (see B<capabilities>(7))."
2238 #: build/C/man2/prctl.2:638
2240 "I<option> is B<PR_CAPBSET_DROP>, and the caller does not have the "
2241 "B<CAP_SETPCAP> capability."
2244 #. FIXME The following (until ========) is not yet in mainline kernel,
2245 #. so commented out for the moment.
2254 #. .BR PR_SET_MM_EXE_FILE ,
2255 #. the file is not executable.
2263 #. .BR PR_SET_MM_EXE_FILE ,
2264 #. and this the second attempt to change the
2266 #. symbolic link, which is prohibited.
2274 #. .BR PR_SET_MM_EXE_FILE ,
2275 #. and the file descriptor passed in
2278 #. ========== END FIXME
2279 #. The following can't actually happen, because prctl() in
2280 #. seccomp mode will cause SIGKILL.
2285 #. .BR PR_SET_SECCOMP ,
2286 #. and secure computing mode is already 1.
2288 #: build/C/man2/prctl.2:689
2290 "I<option> is B<PR_SET_MM>, and the caller does not have the "
2291 "B<CAP_SYS_RESOURCE> capability."
2294 #. The library interface was added in glibc 2.0.6
2296 #: build/C/man2/prctl.2:694
2297 msgid "The B<prctl>() system call was introduced in Linux 2.1.57."
2301 #: build/C/man2/prctl.2:701
2303 "This call is Linux-specific. IRIX has a B<prctl>() system call (also "
2304 "introduced in Linux 2.1.44 as irix_prctl on the MIPS architecture), with "
2309 #: build/C/man2/prctl.2:703
2310 msgid "B<ptrdiff_t prctl(int >I<option>B<, int >I<arg2>B<, int >I<arg3>B<);>"
2314 #: build/C/man2/prctl.2:708
2316 "and options to get the maximum number of processes per user, get the maximum "
2317 "number of processors the calling process can use, find out whether a "
2318 "specified process is currently blocked, get or set the maximum stack size, "
2323 #: build/C/man2/prctl.2:710
2324 msgid "B<signal>(2), B<core>(5)"
2328 #: build/C/man3/profil.3:28
2334 #: build/C/man3/profil.3:31
2335 msgid "profil - execution time profile"
2339 #: build/C/man3/profil.3:36
2341 "B<int profil(unsigned short *>I<buf>B<, size_t >I<bufsiz>B<, size_t "
2342 ">I<offset>B<, unsigned int >I<scale>B<);>"
2346 #: build/C/man3/profil.3:44
2347 msgid "B<profil>(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE\\ E<lt>\\ 500)"
2351 #: build/C/man3/profil.3:66
2353 "This routine provides a means to find out in what areas your program spends "
2354 "most of its time. The argument I<buf> points to I<bufsiz> bytes of core. "
2355 "Every virtual 10 milliseconds, the user's program counter (PC) is examined: "
2356 "I<offset> is subtracted and the result is multiplied by I<scale> and divided "
2357 "by 65536. If the resulting value is less than I<bufsiz>, then the "
2358 "corresponding entry in I<buf> is incremented. If I<buf> is NULL, profiling "
2363 #: build/C/man3/profil.3:68
2364 msgid "Zero is always returned."
2368 #: build/C/man3/profil.3:70
2369 msgid "Similar to a call in SVr4 (but not POSIX.1-2001)."
2373 #: build/C/man3/profil.3:76
2375 "B<profil>() cannot be used on a program that also uses B<ITIMER_PROF> "
2376 "interval timers (see B<setitimer>(2))."
2380 #: build/C/man3/profil.3:79
2382 "True kernel profiling provides more accurate results. Libc 4.4 contained a "
2383 "kernel patch providing a system call profil."
2387 #: build/C/man3/profil.3:83
2388 msgid "B<gprof>(1), B<setitimer>(2), B<sigaction>(2), B<signal>(2)"
2392 #: build/C/man3/psignal.3:28
2398 #: build/C/man3/psignal.3:28
2404 #: build/C/man3/psignal.3:28 build/C/man3/raise.3:27 build/C/man7/sigevent.7:24
2410 #: build/C/man3/psignal.3:31
2411 msgid "psignal, psiginfo - print signal message"
2415 #: build/C/man3/psignal.3:37
2418 "B<void psignal(int >I<sig>B<, const char *>I<s>B<);>\n"
2419 "B<void psiginfo(const siginfo_t *>I<pinfo>B<, const char *>I<s>B<);>\n"
2423 #: build/C/man3/psignal.3:39
2425 msgid "B<extern const char *const >I<sys_siglist>B<[];>\n"
2429 #: build/C/man3/psignal.3:48
2430 msgid "B<psignal>(): _SVID_SOURCE || _BSD_SOURCE"
2434 #: build/C/man3/psignal.3:51
2436 "B<psiginfo>(): _XOPEN_SOURCE\\ E<gt>=\\ 700 || _POSIX_C_SOURCE\\ E<gt>=\\ "
2441 #: build/C/man3/psignal.3:54
2442 msgid "I<sys_siglist>: _BSD_SOURCE"
2446 #: build/C/man3/psignal.3:63
2448 "The B<psignal>() function displays a message on I<stderr> consisting of the "
2449 "string I<s>, a colon, a space, a string describing the signal number I<sig>, "
2450 "and a trailing newline. If the string I<s> is NULL or empty, the colon and "
2451 "space are omitted. If I<sig> is invalid, the message displayed will "
2452 "indicate an unknown signal."
2456 #: build/C/man3/psignal.3:84
2458 "The B<psiginfo>() function is like B<psignal>(), except that it displays "
2459 "information about the signal described by I<pinfo>, which should point to a "
2460 "valid I<siginfo_t> structure. As well as the signal description, "
2461 "B<psiginfo>() displays information about the origin of the signal, and "
2462 "other information relevant to the signal (e.g., the relevant memory address "
2463 "for hardware-generated signals, the child process ID for B<SIGCHLD>, and the "
2464 "user ID and process ID of the sender, for signals set using B<kill>(2) or "
2469 #: build/C/man3/psignal.3:87
2471 "The array I<sys_siglist> holds the signal description strings indexed by "
2476 #: build/C/man3/psignal.3:93
2477 msgid "The B<psignal>() and B<psiginfo>() functions return no value."
2481 #: build/C/man3/psignal.3:97
2482 msgid "The B<psiginfo>() function was added to glibc in version 2.10."
2486 #: build/C/man3/psignal.3:99
2487 msgid "POSIX.1-2008, 4.3BSD."
2491 #: build/C/man3/psignal.3:103
2492 msgid "In glibc versions up to 2.12, B<psiginfo>() had the following bugs:"
2495 #. FIXME http://sourceware.org/bugzilla/show_bug.cgi?id=12107
2496 #. Reportedly now fixed; check glibc 2.13
2498 #: build/C/man3/psignal.3:107
2499 msgid "In some circumstances, a trailing newline is not printed."
2502 #. FIXME http://sourceware.org/bugzilla/show_bug.cgi?id=12108
2503 #. Reportedly now fixed; check glibc 2.13
2505 #: build/C/man3/psignal.3:111
2506 msgid "Additional details are not displayed for real-time signals."
2510 #: build/C/man3/psignal.3:115
2511 msgid "B<sigaction>(2), B<perror>(3), B<strsignal>(3), B<signal>(7)"
2515 #: build/C/man3/raise.3:27
2521 #: build/C/man3/raise.3:27
2527 #: build/C/man3/raise.3:30
2528 msgid "raise - send a signal to the caller"
2532 #: build/C/man3/raise.3:35
2534 msgid "B<int raise(int >I<sig>B<);>\n"
2538 #: build/C/man3/raise.3:41
2540 "The B<raise>() function sends a signal to the calling process or thread. "
2541 "In a single-threaded program it is equivalent to"
2545 #: build/C/man3/raise.3:45
2547 msgid "kill(getpid(), sig);\n"
2551 #: build/C/man3/raise.3:49
2552 msgid "In a multithreaded program it is equivalent to"
2556 #: build/C/man3/raise.3:53
2558 msgid "pthread_kill(pthread_self(), sig);\n"
2562 #: build/C/man3/raise.3:59
2564 "If the signal causes a handler to be called, B<raise>() will only return "
2565 "after the signal handler has returned."
2569 #: build/C/man3/raise.3:62
2570 msgid "B<raise>() returns 0 on success, and nonzero for failure."
2574 #: build/C/man3/raise.3:64 build/C/man2/signal.2:107
2575 msgid "C89, C99, POSIX.1-2001."
2579 #: build/C/man3/raise.3:70
2581 "B<getpid>(2), B<kill>(2), B<sigaction>(2), B<signal>(2), B<pthread_kill>(3), "
2586 #: build/C/man2/rt_sigqueueinfo.2:23
2588 msgid "RT_SIGQUEUEINFO"
2592 #: build/C/man2/rt_sigqueueinfo.2:23 build/C/man7/signal.7:44 build/C/man2/tkill.2:29
2598 #: build/C/man2/rt_sigqueueinfo.2:26
2599 msgid "rt_sigqueueinfo, rt_tgsigqueueinfo - queue a signal and data"
2603 #: build/C/man2/rt_sigqueueinfo.2:29
2606 "B<int rt_sigqueueinfo(pid_t >I<tgid>B<, int >I<sig>B<, siginfo_t "
2611 #: build/C/man2/rt_sigqueueinfo.2:32
2614 "B<int rt_tgsigqueueinfo(pid_t >I<tgid>B<, pid_t >I<tid>B<, int >I<sig>B<,>\n"
2615 "B< siginfo_t *>I<uinfo>B<);>\n"
2619 #: build/C/man2/rt_sigqueueinfo.2:45
2621 "The B<rt_sigqueueinfo>() and B<rt_tgsigqueueinfo>() system calls are the "
2622 "low-level interfaces used to send a signal plus data to a process or "
2623 "thread. The receiver of the signal can obtain the accompanying data by "
2624 "establishing a signal handler with the B<sigaction>(2) B<SA_SIGINFO> flag."
2628 #: build/C/man2/rt_sigqueueinfo.2:51
2630 "These system calls are not intended for direct application use; they are "
2631 "provided to allow the implementation of B<sigqueue>(3) and "
2632 "B<pthread_sigqueue>(3)."
2636 #: build/C/man2/rt_sigqueueinfo.2:63
2638 "The B<rt_sigqueueinfo>() system call sends the signal I<sig> to the thread "
2639 "group with the ID I<tgid>. (The term \"thread group\" is synonymous with "
2640 "\"process\", and I<tid> corresponds to the traditional UNIX process ID.) "
2641 "The signal will be delivered to an arbitrary member of the thread group "
2642 "(i.e., one of the threads that is not currently blocking the signal)."
2646 #: build/C/man2/rt_sigqueueinfo.2:74
2648 "The I<uinfo> argument specifies the data to accompany the signal. This "
2649 "argument is a pointer to a structure of type I<siginfo_t>, described in "
2650 "B<sigaction>(2) (and defined by including I<E<lt>sigaction.hE<gt>>). The "
2651 "caller should set the following fields in this structure:"
2655 #: build/C/man2/rt_sigqueueinfo.2:74 build/C/man7/sigevent.7:86 build/C/man2/wait.2:315
2662 #: build/C/man2/rt_sigqueueinfo.2:90
2664 "This must be one of the B<SI_*> codes in the kernel source file "
2665 "I<include/asm-generic/siginfo.h>, with the restriction that the code must be "
2666 "negative (i.e., cannot be B<SI_USER>, which is used by the kernel to "
2667 "indicate a signal sent by B<kill>(2)) and cannot (since Linux 2.6.39) be "
2668 "B<SI_TKILL> (which is used by the kernel to indicate a signal sent using "
2673 #: build/C/man2/rt_sigqueueinfo.2:90 build/C/man2/wait.2:294
2679 #: build/C/man2/rt_sigqueueinfo.2:94
2680 msgid "This should be set to a process ID, typically the process ID of the sender."
2684 #: build/C/man2/rt_sigqueueinfo.2:94 build/C/man2/wait.2:297
2690 #: build/C/man2/rt_sigqueueinfo.2:98
2691 msgid "This should be set to a user ID, typically the real user ID of the sender."
2695 #: build/C/man2/rt_sigqueueinfo.2:98 build/C/man7/sigevent.7:94
2701 #: build/C/man2/rt_sigqueueinfo.2:105
2703 "This field contains the user data to accompany the signal. For more "
2704 "information, see the description of the last (I<union sigval>) argument of "
2709 #: build/C/man2/rt_sigqueueinfo.2:112
2711 "Internally, the kernel sets the I<si_signo> field to the value specified in "
2712 "I<sig>, so that the receiver of the signal can also obtain the signal number "
2717 #: build/C/man2/rt_sigqueueinfo.2:124
2719 "The B<rt_tgsigqueueinfo>() system call is like B<rt_sigqueueinfo>(), but "
2720 "sends the signal and data to the single thread specified by the combination "
2721 "of I<tgid>, a thread group ID, and I<tid>, a thread in that thread group."
2725 #: build/C/man2/rt_sigqueueinfo.2:129
2727 "On success, these system calls return 0. On error, they return -1 and "
2728 "I<errno> is set to indicate the error."
2732 #: build/C/man2/rt_sigqueueinfo.2:130 build/C/man3/sigqueue.3:90 build/C/man2/sigwaitinfo.2:108 build/C/man2/timer_create.2:174
2738 #: build/C/man2/rt_sigqueueinfo.2:136 build/C/man3/sigqueue.3:96
2740 "The limit of signals which may be queued has been reached. (See "
2741 "B<signal>(7) for further information.)"
2745 #: build/C/man2/rt_sigqueueinfo.2:143
2746 msgid "I<sig>, I<tgid>, or I<tid> was invalid."
2750 #: build/C/man2/rt_sigqueueinfo.2:151
2752 "The caller does not have permission to send the signal to the target. For "
2753 "the required permissions, see B<kill>(2). Or: I<uinfo-E<gt>si_code> is "
2758 #: build/C/man2/rt_sigqueueinfo.2:157
2759 msgid "B<rt_sigqueueinfo>(): No thread group matching I<tgid> was found."
2763 #: build/C/man2/rt_sigqueueinfo.2:164
2764 msgid "B<rt_tgsigqueinfo>(): No thread matching I<tgid> and I<tid> was found."
2768 #: build/C/man2/rt_sigqueueinfo.2:171
2770 "The B<rt_sigqueueinfo>() system call was added to Linux in version 2.2. "
2771 "The B<rt_tgsigqueueinfo>() system call was added to Linux in version "
2776 #: build/C/man2/rt_sigqueueinfo.2:173 build/C/man2/sgetmask.2:63 build/C/man2/timerfd_create.2:372
2777 msgid "These system calls are Linux-specific."
2781 #: build/C/man2/rt_sigqueueinfo.2:178
2783 "Since these system calls are not intended for application use, there are no "
2784 "glibc wrapper functions; use B<syscall>(2) in the unlikely case that you "
2785 "want to call them directly."
2789 #: build/C/man2/rt_sigqueueinfo.2:183
2791 "As with B<kill>(2), the null signal (0) can be used to check if the "
2792 "specified process or thread exists."
2796 #: build/C/man2/rt_sigqueueinfo.2:190
2798 "B<kill>(2), B<sigaction>(2), B<sigprocmask>(2), B<tgkill>(2), "
2799 "B<pthread_sigqueue>(3), B<sigqueue>(3), B<signal>(7)"
2803 #: build/C/man2/sgetmask.2:24
2809 #: build/C/man2/sgetmask.2:24
2815 #: build/C/man2/sgetmask.2:27
2816 msgid "sgetmask, ssetmask - manipulation of signal mask (obsolete)"
2820 #: build/C/man2/sgetmask.2:29
2821 msgid "B<long sgetmask(void);>"
2825 #: build/C/man2/sgetmask.2:31
2826 msgid "B<long ssetmask(long >I<newmask>B<);>"
2830 #: build/C/man2/sgetmask.2:37
2832 "These system calls are obsolete. I<Do not use them>; use B<sigprocmask>(2) "
2837 #: build/C/man2/sgetmask.2:40
2838 msgid "B<sgetmask>() returns the signal mask of the calling process."
2842 #: build/C/man2/sgetmask.2:45
2844 "B<ssetmask>() sets the signal mask of the calling process to the value "
2845 "given in I<newmask>. The previous signal mask is returned."
2849 #: build/C/man2/sgetmask.2:54
2851 "The signal masks dealt with by these two system calls are plain bit masks "
2852 "(unlike the I<sigset_t> used by B<sigprocmask>(2)); use B<sigmask>(3) to "
2853 "create and inspect these masks."
2857 #: build/C/man2/sgetmask.2:59
2859 "B<sgetmask>() always successfully returns the signal mask. B<ssetmask>() "
2860 "always succeeds, and returns the previous signal mask."
2864 #: build/C/man2/sgetmask.2:61
2865 msgid "These system calls always succeed."
2869 #: build/C/man2/sgetmask.2:66
2870 msgid "Glibc does not provide wrappers for these system calls; use B<syscall>(2)."
2874 #: build/C/man2/sgetmask.2:69
2876 "These system calls are unaware of signal numbers greater than 31 (i.e., "
2877 "real-time signals)."
2881 #: build/C/man2/sgetmask.2:74
2882 msgid "It is not possible to block B<SIGSTOP> or B<SIGKILL>."
2886 #: build/C/man2/sgetmask.2:76
2887 msgid "B<sigprocmask>(2), B<signal>(7)"
2891 #: build/C/man2/sigaction.2:45
2897 #: build/C/man2/sigaction.2:45
2903 #: build/C/man2/sigaction.2:48
2904 msgid "sigaction - examine and change a signal action"
2908 #: build/C/man2/sigaction.2:54
2911 "B<int sigaction(int >I<signum>B<, const struct sigaction *>I<act>B<,>\n"
2912 "B< struct sigaction *>I<oldact>B<);>\n"
2916 #: build/C/man2/sigaction.2:64
2918 "B<sigaction>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
2923 #: build/C/man2/sigaction.2:73
2925 "The B<sigaction>() system call is used to change the action taken by a "
2926 "process on receipt of a specific signal. (See B<signal>(7) for an overview "
2931 #: build/C/man2/sigaction.2:79
2933 "I<signum> specifies the signal and can be any valid signal except B<SIGKILL> "
2938 #: build/C/man2/sigaction.2:90
2940 "If I<act> is non-NULL, the new action for signal I<signum> is installed from "
2941 "I<act>. If I<oldact> is non-NULL, the previous action is saved in "
2946 #: build/C/man2/sigaction.2:94
2947 msgid "The I<sigaction> structure is defined as something like:"
2951 #: build/C/man2/sigaction.2:104
2954 "struct sigaction {\n"
2955 " void (*sa_handler)(int);\n"
2956 " void (*sa_sigaction)(int, siginfo_t *, void *);\n"
2957 " sigset_t sa_mask;\n"
2959 " void (*sa_restorer)(void);\n"
2964 #: build/C/man2/sigaction.2:111
2966 "On some architectures a union is involved: do not assign to both "
2967 "I<sa_handler> and I<sa_sigaction>."
2971 #: build/C/man2/sigaction.2:118
2973 "The I<sa_restorer> element is obsolete and should not be used. POSIX does "
2974 "not specify a I<sa_restorer> element."
2978 #: build/C/man2/sigaction.2:128
2980 "I<sa_handler> specifies the action to be associated with I<signum> and may "
2981 "be B<SIG_DFL> for the default action, B<SIG_IGN> to ignore this signal, or a "
2982 "pointer to a signal handling function. This function receives the signal "
2983 "number as its only argument."
2987 #: build/C/man2/sigaction.2:150
2989 "If B<SA_SIGINFO> is specified in I<sa_flags>, then I<sa_sigaction> (instead "
2990 "of I<sa_handler>) specifies the signal-handling function for I<signum>. "
2991 "This function receives the signal number as its first argument, a pointer to "
2992 "a I<siginfo_t> as its second argument and a pointer to a I<ucontext_t> (cast "
2993 "to I<void\\ *>) as its third argument. (Commonly, the handler function "
2994 "doesn't make any use of the third argument. See B<getcontext>(2) for "
2995 "further information about I<ucontext_t>.)"
2999 #: build/C/man2/sigaction.2:160
3001 "I<sa_mask> specifies a mask of signals which should be blocked (i.e., added "
3002 "to the signal mask of the thread in which the signal handler is invoked) "
3003 "during execution of the signal handler. In addition, the signal which "
3004 "triggered the handler will be blocked, unless the B<SA_NODEFER> flag is "
3009 #: build/C/man2/sigaction.2:164
3011 "I<sa_flags> specifies a set of flags which modify the behavior of the "
3012 "signal. It is formed by the bitwise OR of zero or more of the following:"
3016 #: build/C/man2/sigaction.2:165
3018 msgid "B<SA_NOCLDSTOP>"
3022 #: build/C/man2/sigaction.2:182
3024 "If I<signum> is B<SIGCHLD>, do not receive notification when child processes "
3025 "stop (i.e., when they receive one of B<SIGSTOP>, B<SIGTSTP>, B<SIGTTIN> or "
3026 "B<SIGTTOU>) or resume (i.e., they receive B<SIGCONT>) (see B<wait>(2)). "
3027 "This flag is only meaningful when establishing a handler for B<SIGCHLD>."
3031 #: build/C/man2/sigaction.2:182
3033 msgid "B<SA_NOCLDWAIT> (since Linux 2.6)"
3036 #. To be precise: Linux 2.5.60 -- MTK
3038 #: build/C/man2/sigaction.2:196
3040 "If I<signum> is B<SIGCHLD>, do not transform children into zombies when they "
3041 "terminate. See also B<waitpid>(2). This flag is only meaningful when "
3042 "establishing a handler for B<SIGCHLD>, or when setting that signal's "
3043 "disposition to B<SIG_DFL>."
3047 #: build/C/man2/sigaction.2:208
3049 "If the B<SA_NOCLDWAIT> flag is set when establishing a handler for "
3050 "B<SIGCHLD>, POSIX.1 leaves it unspecified whether a B<SIGCHLD> signal is "
3051 "generated when a child process terminates. On Linux, a B<SIGCHLD> signal is "
3052 "generated in this case; on some other implementations, it is not."
3056 #: build/C/man2/sigaction.2:208
3058 msgid "B<SA_NODEFER>"
3062 #: build/C/man2/sigaction.2:215
3064 "Do not prevent the signal from being received from within its own signal "
3065 "handler. This flag is only meaningful when establishing a signal handler. "
3066 "B<SA_NOMASK> is an obsolete, nonstandard synonym for this flag."
3070 #: build/C/man2/sigaction.2:215
3072 msgid "B<SA_ONSTACK>"
3076 #: build/C/man2/sigaction.2:221
3078 "Call the signal handler on an alternate signal stack provided by "
3079 "B<sigaltstack>(2). If an alternate stack is not available, the default "
3080 "stack will be used. This flag is only meaningful when establishing a signal "
3085 #: build/C/man2/sigaction.2:221
3087 msgid "B<SA_RESETHAND>"
3091 #: build/C/man2/sigaction.2:228
3093 "Restore the signal action to the default state once the signal handler has "
3094 "been called. This flag is only meaningful when establishing a signal "
3095 "handler. B<SA_ONESHOT> is an obsolete, nonstandard synonym for this flag."
3099 #: build/C/man2/sigaction.2:228
3101 msgid "B<SA_RESTART>"
3105 #: build/C/man2/sigaction.2:236
3107 "Provide behavior compatible with BSD signal semantics by making certain "
3108 "system calls restartable across signals. This flag is only meaningful when "
3109 "establishing a signal handler. See B<signal>(7) for a discussion of system "
3114 #: build/C/man2/sigaction.2:236
3116 msgid "B<SA_SIGINFO> (since Linux 2.2)"
3121 #. field was added in Linux 2.1.86.)
3123 #: build/C/man2/sigaction.2:247
3125 "The signal handler takes 3 arguments, not one. In this case, "
3126 "I<sa_sigaction> should be set instead of I<sa_handler>. This flag is only "
3127 "meaningful when establishing a signal handler."
3131 #: build/C/man2/sigaction.2:254
3133 "The I<siginfo_t> argument to I<sa_sigaction> is a struct with the following "
3138 #. si_trapno seems to be only used on SPARC and Alpha;
3139 #. this page could use a little more detail on its purpose there.
3140 #. In the kernel: si_tid
3142 #: build/C/man2/sigaction.2:285
3146 " int si_signo; /* Signal number */\n"
3147 " int si_errno; /* An errno value */\n"
3148 " int si_code; /* Signal code */\n"
3149 " int si_trapno; /* Trap number that caused\n"
3150 " hardware-generated signal\n"
3151 " (unused on most architectures) */\n"
3152 " pid_t si_pid; /* Sending process ID */\n"
3153 " uid_t si_uid; /* Real user ID of sending process */\n"
3154 " int si_status; /* Exit value or signal */\n"
3155 " clock_t si_utime; /* User time consumed */\n"
3156 " clock_t si_stime; /* System time consumed */\n"
3157 " sigval_t si_value; /* Signal value */\n"
3158 " int si_int; /* POSIX.1b signal */\n"
3159 " void *si_ptr; /* POSIX.1b signal */\n"
3160 " int si_overrun; /* Timer overrun count; POSIX.1b timers */\n"
3161 " int si_timerid; /* Timer ID; POSIX.1b timers */\n"
3162 " void *si_addr; /* Memory location which caused fault */\n"
3163 " long si_band; /* Band event (was I<int> in\n"
3164 " glibc 2.3.2 and earlier) */\n"
3165 " int si_fd; /* File descriptor */\n"
3166 " short si_addr_lsb; /* Least significant bit of address\n"
3167 " (since kernel 2.6.32) */\n"
3172 #: build/C/man2/sigaction.2:294
3174 "I<si_signo>, I<si_errno> and I<si_code> are defined for all signals. "
3175 "(I<si_errno> is generally unused on Linux.) The rest of the struct may be a "
3176 "union, so that one should only read the fields that are meaningful for the "
3181 #: build/C/man2/sigaction.2:309
3183 "Signals sent with B<kill>(2) and B<sigqueue>(3) fill in I<si_pid> and "
3184 "I<si_uid>. In addition, signals sent with B<sigqueue>(3) fill in I<si_int> "
3185 "and I<si_ptr> with the values specified by the sender of the signal; see "
3186 "B<sigqueue>(3) for more details."
3190 #: build/C/man2/sigaction.2:325
3192 "Signals sent by POSIX.1b timers (since Linux 2.6) fill in I<si_overrun> and "
3193 "I<si_timerid>. The I<si_timerid> field is an internal ID used by the kernel "
3194 "to identify the timer; it is not the same as the timer ID returned by "
3195 "B<timer_create>(2). The I<si_overrun> field is the timer overrun count; "
3196 "this is the same information as is obtained by a call to "
3197 "B<timer_getoverrun>(2). These fields are nonstandard Linux extensions."
3201 #: build/C/man2/sigaction.2:340
3203 "Signals sent for message queue notification (see the description of "
3204 "B<SIGEV_SIGNAL> in B<mq_notify>(3)) fill in I<si_int>/I<si_ptr>, with the "
3205 "I<sigev_value> supplied to B<mq_notify>(3); I<si_pid>, with the process ID "
3206 "of the message sender; and I<si_uid>, with the real user ID of the message "
3211 #. When si_utime and si_stime where originally implemented, the
3212 #. measurement unit was HZ, which was the same as clock ticks
3213 #. (sysconf(_SC_CLK_TCK)). In 2.6, HZ became configurable, and
3214 #. was *still* used as the unit to return the info these fields,
3215 #. with the result that the field values depended on the the
3216 #. configured HZ. Of course, the should have been measured in
3217 #. USER_HZ instead, so that sysconf(_SC_CLK_TCK) could be used to
3218 #. convert to seconds. I have a queued patch to fix this:
3219 #. http://thread.gmane.org/gmane.linux.kernel/698061/ .
3220 #. This patch made it into 2.6.27.
3221 #. But note that these fields still don't return the times of
3222 #. waited-for children (as is done by getrusage() and times()
3223 #. and wait4()). Solaris 8 does include child times.
3225 #: build/C/man2/sigaction.2:387
3227 "B<SIGCHLD> fills in I<si_pid>, I<si_uid>, I<si_status>, I<si_utime> and "
3228 "I<si_stime>, providing information about the child. The I<si_pid> field is "
3229 "the process ID of the child; I<si_uid> is the child's real user ID. The "
3230 "I<si_status> field contains the exit status of the child (if I<si_code> is "
3231 "B<CLD_EXITED>), or the signal number that caused the process to change "
3232 "state. The I<si_utime> and I<si_stime> contain the user and system CPU time "
3233 "used by the child process; these fields do not include the times used by "
3234 "waited-for children (unlike B<getrusage>(2) and B<time>(2)). In kernels up "
3235 "to 2.6, and since 2.6.27, these fields report CPU time in units of "
3236 "I<sysconf(_SC_CLK_TCK)>. In 2.6 kernels before 2.6.27, a bug meant that "
3237 "these fields reported time in units of the (configurable) system jiffy (see "
3241 #. FIXME SIGTRAP also sets the following for ptrace_notify() ?
3242 #. info.si_code = exit_code;
3243 #. info.si_pid = task_pid_vnr(current);
3244 #. info.si_uid = current_uid(); /* Real UID */
3246 #: build/C/man2/sigaction.2:423
3248 "B<SIGILL>, B<SIGFPE>, B<SIGSEGV>, B<SIGBUS>, and B<SIGTRAP> fill in "
3249 "I<si_addr> with the address of the fault. On some architectures, these "
3250 "signals also fill in the I<si_trapno> filed. Some suberrors of B<SIGBUS>, "
3251 "in particular B<BUS_MCEERR_AO> and B<BUS_MCEERR_AR>, also fill in "
3252 "I<si_addr_lsb>. This field indicates the least significant bit of the "
3253 "reported address and therefore the extent of the corruption. For example, "
3254 "if a full page was corrupted, I<si_addr_lsb> contains "
3255 "I<log2(sysconf(_SC_PAGESIZE))>. B<BUS_MCERR_*> and I<si_addr_lsb> are "
3256 "Linux-specific extensions."
3260 #: build/C/man2/sigaction.2:437
3262 "B<SIGIO>/B<SIGPOLL> (the two names are synonyms on Linux) fills in "
3263 "I<si_band> and I<si_fd>. The I<si_band> event is a bit mask containing the "
3264 "same values as are filled in the I<revents> field by B<poll>(2). The "
3265 "I<si_fd> field indicates the file descriptor for which the I/O event "
3270 #: build/C/man2/sigaction.2:444
3272 "I<si_code> is a value (not a bit mask) indicating why this signal was "
3273 "sent. The following list shows the values which can be placed in I<si_code> "
3274 "for any signal, along with reason that the signal was generated."
3278 #: build/C/man2/sigaction.2:445
3284 #: build/C/man2/sigaction.2:450
3285 msgid "B<kill>(2) or B<raise>(3)"
3289 #: build/C/man2/sigaction.2:450
3291 msgid "B<SI_KERNEL>"
3295 #: build/C/man2/sigaction.2:453
3296 msgid "Sent by the kernel."
3300 #: build/C/man2/sigaction.2:453
3306 #: build/C/man2/sigaction.2:456 build/C/man7/signal.7:126
3308 msgid "B<sigqueue>(3)"
3312 #: build/C/man2/sigaction.2:456
3318 #: build/C/man2/sigaction.2:459
3319 msgid "POSIX timer expired"
3323 #: build/C/man2/sigaction.2:459
3329 #: build/C/man2/sigaction.2:463
3330 msgid "POSIX message queue state changed (since Linux 2.6.6); see B<mq_notify>(3)"
3334 #: build/C/man2/sigaction.2:463
3336 msgid "B<SI_ASYNCIO>"
3340 #: build/C/man2/sigaction.2:466
3341 msgid "AIO completed"
3345 #: build/C/man2/sigaction.2:466
3351 #: build/C/man2/sigaction.2:475
3353 "Queued B<SIGIO> (only in kernels up to Linux 2.2; from Linux 2.4 onward "
3354 "B<SIGIO>/B<SIGPOLL> fills in I<si_code> as described below)."
3358 #: build/C/man2/sigaction.2:475
3363 #. SI_DETHREAD is defined in 2.6.9 sources, but isn't implemented
3364 #. It appears to have been an idea that was tried during 2.5.6
3365 #. through to 2.5.24 and then was backed out.
3367 #: build/C/man2/sigaction.2:484
3368 msgid "B<tkill>(2) or B<tgkill>(2) (since Linux 2.4.19)"
3372 #: build/C/man2/sigaction.2:491
3373 msgid "The following values can be placed in I<si_code> for a B<SIGILL> signal:"
3377 #: build/C/man2/sigaction.2:492
3379 msgid "B<ILL_ILLOPC>"
3383 #: build/C/man2/sigaction.2:495
3384 msgid "illegal opcode"
3388 #: build/C/man2/sigaction.2:495
3390 msgid "B<ILL_ILLOPN>"
3394 #: build/C/man2/sigaction.2:498
3395 msgid "illegal operand"
3399 #: build/C/man2/sigaction.2:498
3401 msgid "B<ILL_ILLADR>"
3405 #: build/C/man2/sigaction.2:501
3406 msgid "illegal addressing mode"
3410 #: build/C/man2/sigaction.2:501
3412 msgid "B<ILL_ILLTRP>"
3416 #: build/C/man2/sigaction.2:504
3417 msgid "illegal trap"
3421 #: build/C/man2/sigaction.2:504
3423 msgid "B<ILL_PRVOPC>"
3427 #: build/C/man2/sigaction.2:507
3428 msgid "privileged opcode"
3432 #: build/C/man2/sigaction.2:507
3434 msgid "B<ILL_PRVREG>"
3438 #: build/C/man2/sigaction.2:510
3439 msgid "privileged register"
3443 #: build/C/man2/sigaction.2:510
3445 msgid "B<ILL_COPROC>"
3449 #: build/C/man2/sigaction.2:513
3450 msgid "coprocessor error"
3454 #: build/C/man2/sigaction.2:513
3456 msgid "B<ILL_BADSTK>"
3460 #: build/C/man2/sigaction.2:516
3461 msgid "internal stack error"
3465 #: build/C/man2/sigaction.2:523
3466 msgid "The following values can be placed in I<si_code> for a B<SIGFPE> signal:"
3470 #: build/C/man2/sigaction.2:524
3472 msgid "B<FPE_INTDIV>"
3476 #: build/C/man2/sigaction.2:527
3477 msgid "integer divide by zero"
3481 #: build/C/man2/sigaction.2:527
3483 msgid "B<FPE_INTOVF>"
3487 #: build/C/man2/sigaction.2:530
3488 msgid "integer overflow"
3492 #: build/C/man2/sigaction.2:530
3494 msgid "B<FPE_FLTDIV>"
3498 #: build/C/man2/sigaction.2:533
3499 msgid "floating-point divide by zero"
3503 #: build/C/man2/sigaction.2:533
3505 msgid "B<FPE_FLTOVF>"
3509 #: build/C/man2/sigaction.2:536
3510 msgid "floating-point overflow"
3514 #: build/C/man2/sigaction.2:536
3516 msgid "B<FPE_FLTUND>"
3520 #: build/C/man2/sigaction.2:539
3521 msgid "floating-point underflow"
3525 #: build/C/man2/sigaction.2:539
3527 msgid "B<FPE_FLTRES>"
3531 #: build/C/man2/sigaction.2:542
3532 msgid "floating-point inexact result"
3536 #: build/C/man2/sigaction.2:542
3538 msgid "B<FPE_FLTINV>"
3542 #: build/C/man2/sigaction.2:545
3543 msgid "floating-point invalid operation"
3547 #: build/C/man2/sigaction.2:545
3549 msgid "B<FPE_FLTSUB>"
3553 #: build/C/man2/sigaction.2:548
3554 msgid "subscript out of range"
3558 #: build/C/man2/sigaction.2:555
3559 msgid "The following values can be placed in I<si_code> for a B<SIGSEGV> signal:"
3563 #: build/C/man2/sigaction.2:556
3565 msgid "B<SEGV_MAPERR>"
3569 #: build/C/man2/sigaction.2:559
3570 msgid "address not mapped to object"
3574 #: build/C/man2/sigaction.2:559
3576 msgid "B<SEGV_ACCERR>"
3580 #: build/C/man2/sigaction.2:562
3581 msgid "invalid permissions for mapped object"
3585 #: build/C/man2/sigaction.2:569
3586 msgid "The following values can be placed in I<si_code> for a B<SIGBUS> signal:"
3590 #: build/C/man2/sigaction.2:570
3592 msgid "B<BUS_ADRALN>"
3596 #: build/C/man2/sigaction.2:573
3597 msgid "invalid address alignment"
3601 #: build/C/man2/sigaction.2:573
3603 msgid "B<BUS_ADRERR>"
3607 #: build/C/man2/sigaction.2:576
3608 msgid "nonexistent physical address"
3612 #: build/C/man2/sigaction.2:576
3614 msgid "B<BUS_OBJERR>"
3618 #: build/C/man2/sigaction.2:579
3619 msgid "object-specific hardware error"
3623 #: build/C/man2/sigaction.2:579
3625 msgid "B<BUS_MCEERR_AR> (since Linux 2.6.32)"
3629 #: build/C/man2/sigaction.2:582
3630 msgid "Hardware memory error consumed on a machine check; action required."
3634 #: build/C/man2/sigaction.2:582
3636 msgid "B<BUS_MCEERR_AO> (since Linux 2.6.32)"
3640 #: build/C/man2/sigaction.2:585
3641 msgid "Hardware memory error detected in process but not consumed; action optional."
3645 #: build/C/man2/sigaction.2:592
3646 msgid "The following values can be placed in I<si_code> for a B<SIGTRAP> signal:"
3650 #: build/C/man2/sigaction.2:593
3652 msgid "B<TRAP_BRKPT>"
3656 #: build/C/man2/sigaction.2:596
3657 msgid "process breakpoint"
3661 #: build/C/man2/sigaction.2:596
3663 msgid "B<TRAP_TRACE>"
3667 #: build/C/man2/sigaction.2:599
3668 msgid "process trace trap"
3672 #: build/C/man2/sigaction.2:599
3674 msgid "B<TRAP_BRANCH> (since Linux 2.4)"
3678 #: build/C/man2/sigaction.2:602
3679 msgid "process taken branch trap"
3683 #: build/C/man2/sigaction.2:602
3685 msgid "B<TRAP_HWBKPT> (since Linux 2.4)"
3689 #: build/C/man2/sigaction.2:605
3690 msgid "hardware breakpoint/watchpoint"
3694 #: build/C/man2/sigaction.2:612
3695 msgid "The following values can be placed in I<si_code> for a B<SIGCHLD> signal:"
3699 #: build/C/man2/sigaction.2:613
3701 msgid "B<CLD_EXITED>"
3705 #: build/C/man2/sigaction.2:616
3706 msgid "child has exited"
3710 #: build/C/man2/sigaction.2:616
3712 msgid "B<CLD_KILLED>"
3716 #: build/C/man2/sigaction.2:619
3717 msgid "child was killed"
3721 #: build/C/man2/sigaction.2:619
3723 msgid "B<CLD_DUMPED>"
3727 #: build/C/man2/sigaction.2:622
3728 msgid "child terminated abnormally"
3732 #: build/C/man2/sigaction.2:622
3734 msgid "B<CLD_TRAPPED>"
3738 #: build/C/man2/sigaction.2:625
3739 msgid "traced child has trapped"
3743 #: build/C/man2/sigaction.2:625
3745 msgid "B<CLD_STOPPED>"
3749 #: build/C/man2/sigaction.2:628
3750 msgid "child has stopped"
3754 #: build/C/man2/sigaction.2:628
3756 msgid "B<CLD_CONTINUED>"
3760 #: build/C/man2/sigaction.2:631
3761 msgid "stopped child has continued (since Linux 2.6.9)"
3765 #: build/C/man2/sigaction.2:638
3767 "The following values can be placed in I<si_code> for a B<SIGIO>/B<SIGPOLL> "
3772 #: build/C/man2/sigaction.2:639
3778 #: build/C/man2/sigaction.2:642
3779 msgid "data input available"
3783 #: build/C/man2/sigaction.2:642
3789 #: build/C/man2/sigaction.2:645
3790 msgid "output buffers available"
3794 #: build/C/man2/sigaction.2:645
3800 #: build/C/man2/sigaction.2:648
3801 msgid "input message available"
3805 #: build/C/man2/sigaction.2:648
3811 #: build/C/man2/sigaction.2:651
3816 #: build/C/man2/sigaction.2:651
3822 #: build/C/man2/sigaction.2:654
3823 msgid "high priority input available"
3827 #: build/C/man2/sigaction.2:654
3833 #: build/C/man2/sigaction.2:657
3834 msgid "device disconnected"
3838 #: build/C/man2/sigaction.2:661
3839 msgid "B<sigaction>() returns 0 on success and -1 on error."
3843 #: build/C/man2/sigaction.2:666
3845 "I<act> or I<oldact> points to memory which is not a valid part of the "
3846 "process address space."
3850 #: build/C/man2/sigaction.2:673
3852 "An invalid signal was specified. This will also be generated if an attempt "
3853 "is made to change the action for B<SIGKILL> or B<SIGSTOP>, which cannot be "
3854 "caught or ignored."
3857 #. SVr4 does not document the EINTR condition.
3859 #: build/C/man2/sigaction.2:676
3860 msgid "POSIX.1-2001, SVr4."
3864 #: build/C/man2/sigaction.2:684 build/C/man7/signal.7:103
3866 "A child created via B<fork>(2) inherits a copy of its parent's signal "
3867 "dispositions. During an B<execve>(2), the dispositions of handled signals "
3868 "are reset to the default; the dispositions of ignored signals are left "
3873 #: build/C/man2/sigaction.2:702 build/C/man2/signal.2:129
3875 "According to POSIX, the behavior of a process is undefined after it ignores "
3876 "a B<SIGFPE>, B<SIGILL>, or B<SIGSEGV> signal that was not generated by "
3877 "B<kill>(2) or B<raise>(3). Integer division by zero has undefined result. "
3878 "On some architectures it will generate a B<SIGFPE> signal. (Also dividing "
3879 "the most negative integer by -1 may generate B<SIGFPE>.) Ignoring this "
3880 "signal might lead to an endless loop."
3884 #: build/C/man2/sigaction.2:719
3886 "POSIX.1-1990 disallowed setting the action for B<SIGCHLD> to B<SIG_IGN>. "
3887 "POSIX.1-2001 allows this possibility, so that ignoring B<SIGCHLD> can be "
3888 "used to prevent the creation of zombies (see B<wait>(2)). Nevertheless, the "
3889 "historical BSD and System V behaviors for ignoring B<SIGCHLD> differ, so "
3890 "that the only completely portable method of ensuring that terminated "
3891 "children do not become zombies is to catch the B<SIGCHLD> signal and perform "
3892 "a B<wait>(2) or similar."
3896 #: build/C/man2/sigaction.2:732
3898 "POSIX.1-1990 only specified B<SA_NOCLDSTOP>. POSIX.1-2001 added "
3899 "B<SA_NOCLDWAIT>, B<SA_RESETHAND>, B<SA_NODEFER>, and B<SA_SIGINFO>. Use of "
3900 "these latter values in I<sa_flags> may be less portable in applications "
3901 "intended for older UNIX implementations."
3905 #: build/C/man2/sigaction.2:736
3906 msgid "The B<SA_RESETHAND> flag is compatible with the SVr4 flag of the same name."
3910 #: build/C/man2/sigaction.2:746
3912 "The B<SA_NODEFER> flag is compatible with the SVr4 flag of the same name "
3913 "under kernels 1.3.9 and newer. On older kernels the Linux implementation "
3914 "allowed the receipt of any signal, not just the one we are installing "
3915 "(effectively overriding any I<sa_mask> settings)."
3919 #: build/C/man2/sigaction.2:752
3921 "B<sigaction>() can be called with a NULL second argument to query the "
3922 "current signal handler. It can also be used to check whether a given signal "
3923 "is valid for the current machine by calling it with NULL second and third "
3928 #: build/C/man2/sigaction.2:758
3930 "It is not possible to block B<SIGKILL> or B<SIGSTOP> (by specifying them in "
3931 "I<sa_mask>). Attempts to do so are silently ignored."
3935 #: build/C/man2/sigaction.2:762 build/C/man2/sigpending.2:65 build/C/man2/sigprocmask.2:139 build/C/man2/sigsuspend.2:104
3936 msgid "See B<sigsetops>(3) for details on manipulating signal sets."
3940 #: build/C/man2/sigaction.2:767
3942 "See B<signal>(7) for a list of the async-signal-safe functions that can be "
3943 "safely called inside from inside a signal handler."
3947 #: build/C/man2/sigaction.2:767
3949 msgid "Undocumented"
3953 #: build/C/man2/sigaction.2:777
3955 "Before the introduction of B<SA_SIGINFO> it was also possible to get some "
3956 "additional information, namely by using a I<sa_handler> with second argument "
3957 "of type I<struct sigcontext>. See the relevant kernel sources for details. "
3958 "This use is obsolete now."
3962 #: build/C/man2/sigaction.2:786
3964 "In kernels up to and including 2.6.13, specifying B<SA_NODEFER> in "
3965 "I<sa_flags> prevents not only the delivered signal from being masked during "
3966 "execution of the handler, but also the signals specified in I<sa_mask>. "
3967 "This bug was fixed in kernel 2.6.14."
3971 #: build/C/man2/sigaction.2:789
3972 msgid "See B<mprotect>(2)."
3976 #: build/C/man2/sigaction.2:807
3978 "B<kill>(1), B<kill>(2), B<killpg>(2), B<pause>(2), B<sigaltstack>(2), "
3979 "B<signal>(2), B<signalfd>(2), B<sigpending>(2), B<sigprocmask>(2), "
3980 "B<sigsuspend>(2), B<wait>(2), B<raise>(3), B<siginterrupt>(3), "
3981 "B<sigqueue>(3), B<sigsetops>(3), B<sigvec>(3), B<core>(5), B<signal>(7)"
3985 #: build/C/man2/sigaltstack.2:25
3991 #: build/C/man2/sigaltstack.2:25 build/C/man2/wait.2:50
3997 #: build/C/man2/sigaltstack.2:28
3998 msgid "sigaltstack - set and/or get signal stack context"
4002 #: build/C/man2/sigaltstack.2:32
4003 msgid "B<int sigaltstack(const stack_t *>I<ss>B<, stack_t *>I<oss>B<);>"
4007 #: build/C/man2/sigaltstack.2:39
4008 msgid "B<sigaltstack>():"
4012 #: build/C/man2/sigaltstack.2:46 build/C/man3/siginterrupt.3:51 build/C/man2/wait.2:79
4013 msgid "|| /* Since glibc 2.12: */ _POSIX_C_SOURCE\\ E<gt>=\\ 200809L"
4017 #: build/C/man2/sigaltstack.2:58
4019 "B<sigaltstack>() allows a process to define a new alternate signal stack "
4020 "and/or retrieve the state of an existing alternate signal stack. An "
4021 "alternate signal stack is used during the execution of a signal handler if "
4022 "the establishment of that handler (see B<sigaction>(2)) requested it."
4026 #: build/C/man2/sigaltstack.2:61
4028 "The normal sequence of events for using an alternate signal stack is the "
4033 #: build/C/man2/sigaltstack.2:61 build/C/man7/signal.7:383
4039 #: build/C/man2/sigaltstack.2:65
4040 msgid "Allocate an area of memory to be used for the alternate signal stack."
4044 #: build/C/man2/sigaltstack.2:65 build/C/man7/signal.7:387
4050 #: build/C/man2/sigaltstack.2:71
4052 "Use B<sigaltstack>() to inform the system of the existence and location of "
4053 "the alternate signal stack."
4057 #: build/C/man2/sigaltstack.2:71 build/C/man7/signal.7:407
4063 #: build/C/man2/sigaltstack.2:78
4065 "When establishing a signal handler using B<sigaction>(2), inform the system "
4066 "that the signal handler should be executed on the alternate signal stack by "
4067 "specifying the B<SA_ONSTACK> flag."
4071 #: build/C/man2/sigaltstack.2:86
4073 "The I<ss> argument is used to specify a new alternate signal stack, while "
4074 "the I<oss> argument is used to retrieve information about the currently "
4075 "established signal stack. If we are interested in performing just one of "
4076 "these tasks then the other argument can be specified as NULL. Each of these "
4077 "arguments is a structure of the following type:"
4081 #: build/C/man2/sigaltstack.2:94
4084 "typedef struct {\n"
4085 " void *ss_sp; /* Base address of stack */\n"
4086 " int ss_flags; /* Flags */\n"
4087 " size_t ss_size; /* Number of bytes in stack */\n"
4092 #: build/C/man2/sigaltstack.2:105
4094 "To establish a new alternate signal stack, I<ss.ss_flags> is set to zero, "
4095 "and I<ss.ss_sp> and I<ss.ss_size> specify the starting address and size of "
4096 "the stack. The constant B<SIGSTKSZ> is defined to be large enough to cover "
4097 "the usual size requirements for an alternate signal stack, and the constant "
4098 "B<MINSIGSTKSZ> defines the minimum size required to execute a signal "
4103 #: build/C/man2/sigaltstack.2:109
4105 "When a signal handler is invoked on the alternate stack, the kernel "
4106 "automatically aligns the address given in I<ss.ss_sp> to a suitable address "
4107 "boundary for the underlying hardware architecture."
4111 #: build/C/man2/sigaltstack.2:114
4113 "To disable an existing stack, specify I<ss.ss_flags> as B<SS_DISABLE>. In "
4114 "this case, the remaining fields in I<ss> are ignored."
4118 #: build/C/man2/sigaltstack.2:122
4120 "If I<oss> is not NULL, then it is used to return information about the "
4121 "alternate signal stack which was in effect prior to the call to "
4122 "B<sigaltstack>(). The I<oss.ss_sp> and I<oss.ss_size> fields return the "
4123 "starting address and size of that stack. The I<oss.ss_flags> may return "
4124 "either of the following values:"
4128 #: build/C/man2/sigaltstack.2:122
4130 msgid "B<SS_ONSTACK>"
4134 #: build/C/man2/sigaltstack.2:128
4136 "The process is currently executing on the alternate signal stack. (Note "
4137 "that it is not possible to change the alternate signal stack if the process "
4138 "is currently executing on it.)"
4142 #: build/C/man2/sigaltstack.2:128
4144 msgid "B<SS_DISABLE>"
4148 #: build/C/man2/sigaltstack.2:131
4149 msgid "The alternate signal stack is currently disabled."
4153 #: build/C/man2/sigaltstack.2:135
4155 "B<sigaltstack>() returns 0 on success, or -1 on failure with I<errno> set "
4156 "to indicate the error."
4160 #: build/C/man2/sigaltstack.2:140
4162 "Either I<ss> or I<oss> is not NULL and points to an area outside of the "
4163 "process's address space."
4167 #: build/C/man2/sigaltstack.2:145
4169 "I<ss> is not NULL and the I<ss_flags> field contains a nonzero value other "
4170 "than B<SS_DISABLE>."
4174 #: build/C/man2/sigaltstack.2:149
4176 "The specified size of the new alternate signal stack (I<ss.ss_size>) was "
4177 "less than B<MINSTKSZ>."
4181 #: build/C/man2/sigaltstack.2:154
4183 "An attempt was made to change the alternate signal stack while it was active "
4184 "(i.e., the process was already executing on the current alternate signal "
4189 #: build/C/man2/sigaltstack.2:156
4190 msgid "SUSv2, SVr4, POSIX.1-2001."
4194 #: build/C/man2/sigaltstack.2:164
4196 "The most common usage of an alternate signal stack is to handle the "
4197 "B<SIGSEGV> signal that is generated if the space available for the normal "
4198 "process stack is exhausted: in this case, a signal handler for B<SIGSEGV> "
4199 "cannot be invoked on the process stack; if we wish to handle it, we must use "
4200 "an alternate signal stack."
4204 #: build/C/man2/sigaltstack.2:174
4206 "Establishing an alternate signal stack is useful if a process expects that "
4207 "it may exhaust its standard stack. This may occur, for example, because the "
4208 "stack grows so large that it encounters the upwardly growing heap, or it "
4209 "reaches a limit established by a call to B<setrlimit(RLIMIT_STACK, &rlim)>. "
4210 "If the standard stack is exhausted, the kernel sends the process a "
4211 "B<SIGSEGV> signal. In these circumstances the only way to catch this signal "
4212 "is on an alternate signal stack."
4216 #: build/C/man2/sigaltstack.2:180
4218 "On most hardware architectures supported by Linux, stacks grow downward. "
4219 "B<sigaltstack>() automatically takes account of the direction of stack "
4224 #: build/C/man2/sigaltstack.2:189
4226 "Functions called from a signal handler executing on an alternate signal "
4227 "stack will also use the alternate signal stack. (This also applies to any "
4228 "handlers invoked for other signals while the process is executing on the "
4229 "alternate signal stack.) Unlike the standard stack, the system does not "
4230 "automatically extend the alternate signal stack. Exceeding the allocated "
4231 "size of the alternate signal stack will lead to unpredictable results."
4235 #: build/C/man2/sigaltstack.2:197
4237 "A successful call to B<execve>(2) removes any existing alternate signal "
4238 "stack. A child process created via B<fork>(2) inherits a copy of its "
4239 "parent's alternate signal stack settings."
4243 #: build/C/man2/sigaltstack.2:206
4245 "B<sigaltstack>() supersedes the older B<sigstack>() call. For backward "
4246 "compatibility, glibc also provides B<sigstack>(). All new applications "
4247 "should be written using B<sigaltstack>()."
4251 #: build/C/man2/sigaltstack.2:206 build/C/man3/sigpause.3:59
4257 #: build/C/man2/sigaltstack.2:213
4259 "4.2BSD had a B<sigstack>() system call. It used a slightly different "
4260 "struct, and had the major disadvantage that the caller had to know the "
4261 "direction of stack growth."
4265 #: build/C/man2/sigaltstack.2:216
4266 msgid "The following code segment demonstrates the use of B<sigaltstack>():"
4270 #: build/C/man2/sigaltstack.2:220
4272 msgid "stack_t ss;\n"
4276 #: build/C/man2/sigaltstack.2:228
4279 "ss.ss_sp = malloc(SIGSTKSZ);\n"
4280 "if (ss.ss_sp == NULL)\n"
4281 " /* Handle error */;\n"
4282 "ss.ss_size = SIGSTKSZ;\n"
4283 "ss.ss_flags = 0;\n"
4284 "if (sigaltstack(&ss, NULL) == -1)\n"
4285 " /* Handle error */;\n"
4289 #: build/C/man2/sigaltstack.2:236
4291 "B<execve>(2), B<setrlimit>(2), B<sigaction>(2), B<siglongjmp>(3), "
4292 "B<sigsetjmp>(3), B<signal>(7)"
4296 #: build/C/man7/sigevent.7:24
4302 #: build/C/man7/sigevent.7:24 build/C/man3/siginterrupt.3:29
4308 #: build/C/man7/sigevent.7:27
4309 msgid "sigevent - structure for notification from asynchronous routines"
4313 #: build/C/man7/sigevent.7:34
4316 "union sigval { /* Data passed with notification */\n"
4317 " int sival_int; /* Integer value */\n"
4318 " void *sival_ptr; /* Pointer value */\n"
4323 #: build/C/man7/sigevent.7:49
4326 "struct sigevent {\n"
4327 " int sigev_notify; /* Notification method */\n"
4328 " int sigev_signo; /* Notification signal */\n"
4329 " union sigval sigev_value; /* Data passed with\n"
4330 " notification */\n"
4331 " void (*sigev_notify_function) (union sigval);\n"
4332 " /* Function used for thread\n"
4333 " notification (SIGEV_THREAD) */\n"
4334 " void *sigev_notify_attributes;\n"
4335 " /* Attributes for notification thread\n"
4336 " (SIGEV_THREAD) */\n"
4337 " pid_t sigev_notify_thread_id;\n"
4338 " /* ID of thread to signal (SIGEV_THREAD_ID) */\n"
4343 #: build/C/man7/sigevent.7:58
4345 "The I<sigevent> structure is used by various APIs to describe the way a "
4346 "process is to be notified about an event (e.g., completion of an "
4347 "asynchronous request, expiration of a timer, or the arrival of a message)."
4351 #: build/C/man7/sigevent.7:66
4353 "The definition shown in the SYNOPSIS is approximate: some of the fields in "
4354 "the I<sigevent> structure may be defined as part of a union. Programs "
4355 "should only employ those fields relevant to the value specified in "
4360 #: build/C/man7/sigevent.7:71
4362 "The I<sigev_notify> field specifies how notification is to be performed. "
4363 "This field can have one of the following values:"
4367 #: build/C/man7/sigevent.7:71 build/C/man2/timer_create.2:105
4369 msgid "B<SIGEV_NONE>"
4373 #: build/C/man7/sigevent.7:74
4374 msgid "A \"null\" notification: don't do anything when the event occurs."
4378 #: build/C/man7/sigevent.7:74 build/C/man2/timer_create.2:110
4380 msgid "B<SIGEV_SIGNAL>"
4384 #: build/C/man7/sigevent.7:78
4385 msgid "Notify the process by sending the signal specified in I<sigev_signo>."
4389 #: build/C/man7/sigevent.7:85
4391 "If the signal is caught with a signal handler that was registered using the "
4392 "B<sigaction>(2) B<SA_SIGINFO> flag, then the following fields are set in "
4393 "the I<siginfo_t> structure that is passed as the second argument of the "
4398 #: build/C/man7/sigevent.7:90
4400 "This field is set to a value that depends on the API delivering the "
4405 #: build/C/man7/sigevent.7:90 build/C/man2/wait.2:301
4411 #: build/C/man7/sigevent.7:94
4413 "This field is set to the signal number (i.e., the same value as in "
4418 #: build/C/man7/sigevent.7:98
4419 msgid "This field is set to the value specified in I<sigev_value>."
4423 #: build/C/man7/sigevent.7:103
4425 "Depending on the API, other fields may also be set in the I<siginfo_t> "
4430 #: build/C/man7/sigevent.7:106
4432 "The same information is also available if the signal is accepted using "
4433 "B<sigwaitinfo>(2)."
4437 #: build/C/man7/sigevent.7:106 build/C/man2/timer_create.2:128
4439 msgid "B<SIGEV_THREAD>"
4443 #: build/C/man7/sigevent.7:123
4445 "Notify the process by invoking I<sigev_notify_function> \"as if\" it were "
4446 "the start function of a new thread. (Among the implementation possibilities "
4447 "here are that each timer notification could result in the creation of a new "
4448 "thread, or that a single thread is created to receive all notifications.) "
4449 "The function is invoked with I<sigev_value> as its sole argument. If "
4450 "I<sigev_notify_attributes> is not NULL, it should point to a "
4451 "I<pthread_attr_t> structure that defines attributes for the new thread (see "
4452 "B<pthread_attr_init>(3))."
4456 #: build/C/man7/sigevent.7:123 build/C/man2/timer_create.2:136
4458 msgid "B<SIGEV_THREAD_ID> (Linux-specific)"
4461 #. | SIGEV_SIGNAL vs not?
4463 #: build/C/man7/sigevent.7:128
4464 msgid "Currently used only by POSIX timers; see B<timer_create>(2)."
4468 #: build/C/man7/sigevent.7:130 build/C/man2/sigpending.2:61 build/C/man2/sigprocmask.2:109 build/C/man3/sigqueue.3:114 build/C/man3/sigsetops.3:128 build/C/man2/sigsuspend.2:82 build/C/man3/sigwait.3:79 build/C/man2/sigwaitinfo.2:128 build/C/man2/timer_create.2:193 build/C/man2/timer_delete.2:66 build/C/man2/timer_getoverrun.2:96 build/C/man2/timer_settime.2:205
4469 msgid "POSIX.1-2001."
4473 #: build/C/man7/sigevent.7:139
4475 "B<timer_create>(2), B<aio_fsync>(3), B<aio_read>(3), B<aio_write>(3), "
4476 "B<getaddrinfo_a>(3), B<lio_listio>(3), B<mq_notify>(3), B<aio>(7), "
4481 #: build/C/man3/siginterrupt.3:29
4483 msgid "SIGINTERRUPT"
4487 #: build/C/man3/siginterrupt.3:32
4488 msgid "siginterrupt - allow signals to interrupt system calls"
4492 #: build/C/man3/siginterrupt.3:37
4494 msgid "B<int siginterrupt(int >I<sig>B<, int >I<flag>B<);>\n"
4498 #: build/C/man3/siginterrupt.3:45
4499 msgid "B<siginterrupt>():"
4503 #: build/C/man3/siginterrupt.3:62
4505 "The B<siginterrupt>() function changes the restart behavior when a system "
4506 "call is interrupted by the signal I<sig>. If the I<flag> argument is false "
4507 "(0), then system calls will be restarted if interrupted by the specified "
4508 "signal I<sig>. This is the default behavior in Linux."
4512 #: build/C/man3/siginterrupt.3:67
4514 "If the I<flag> argument is true (1) and no data has been transferred, then a "
4515 "system call interrupted by the signal I<sig> will return -1 and I<errno> "
4516 "will be set to B<EINTR>."
4520 #: build/C/man3/siginterrupt.3:71
4522 "If the I<flag> argument is true (1) and data transfer has started, then the "
4523 "system call will be interrupted and will return the actual amount of data "
4528 #: build/C/man3/siginterrupt.3:76
4530 "The B<siginterrupt>() function returns 0 on success, or -1 if the signal "
4531 "number I<sig> is invalid."
4535 #: build/C/man3/siginterrupt.3:80
4536 msgid "The specified signal number is invalid."
4540 #: build/C/man3/siginterrupt.3:89
4542 "4.3BSD, POSIX.1-2001. POSIX.1-2008 marks B<siginterrupt>() as obsolete, "
4543 "recommending the use of B<sigaction>(2) with the B<SA_RESTART> flag "
4548 #: build/C/man3/siginterrupt.3:90
4549 msgid "B<signal>(2)"
4553 #: build/C/man2/signal.2:34 build/C/man7/signal.7:44
4559 #: build/C/man2/signal.2:34
4565 #: build/C/man2/signal.2:37
4566 msgid "signal - ANSI C signal handling"
4570 #: build/C/man2/signal.2:43
4571 msgid "B<sighandler_t signal(int >I<signum>B<, sighandler_t >I<handler>B<);>"
4575 #: build/C/man2/signal.2:52
4577 "The behavior of B<signal>() varies across UNIX versions, and has also "
4578 "varied historically across different versions of Linux. B<Avoid its use>: "
4579 "use B<sigaction>(2) instead. See I<Portability> below."
4583 #: build/C/man2/signal.2:62
4585 "B<signal>() sets the disposition of the signal I<signum> to I<handler>, "
4586 "which is either B<SIG_IGN>, B<SIG_DFL>, or the address of a "
4587 "programmer-defined function (a \"signal handler\")."
4591 #: build/C/man2/signal.2:66
4593 "If the signal I<signum> is delivered to the process, then one of the "
4594 "following happens:"
4598 #: build/C/man2/signal.2:71
4599 msgid "If the disposition is set to B<SIG_IGN>, then the signal is ignored."
4603 #: build/C/man2/signal.2:78
4605 "If the disposition is set to B<SIG_DFL>, then the default action associated "
4606 "with the signal (see B<signal>(7)) occurs."
4610 #: build/C/man2/signal.2:89
4612 "If the disposition is set to a function, then first either the disposition "
4613 "is reset to B<SIG_DFL>, or the signal is blocked (see I<Portability> below), "
4614 "and then I<handler> is called with argument I<signum>. If invocation of the "
4615 "handler caused the signal to be blocked, then the signal is unblocked upon "
4616 "return from the handler."
4620 #: build/C/man2/signal.2:95
4621 msgid "The signals B<SIGKILL> and B<SIGSTOP> cannot be caught or ignored."
4625 #: build/C/man2/signal.2:100
4627 "B<signal>() returns the previous value of the signal handler, or B<SIG_ERR> "
4632 #: build/C/man2/signal.2:105
4633 msgid "I<signum> is invalid."
4637 #: build/C/man2/signal.2:111
4638 msgid "The effects of B<signal>() in a multithreaded process are unspecified."
4642 #: build/C/man2/signal.2:136
4644 "See B<sigaction>(2) for details on what happens when B<SIGCHLD> is set to "
4649 #: build/C/man2/signal.2:141
4651 "See B<signal>(7) for a list of the async-signal-safe functions that can be "
4652 "safely called from inside a signal handler."
4656 #: build/C/man2/signal.2:156
4658 "The use of I<sighandler_t> is a GNU extension. Various versions of libc "
4659 "predefine this type; libc4 and libc5 define I<SignalHandler>; glibc defines "
4660 "I<sig_t> and, when B<_GNU_SOURCE> is defined, also I<sighandler_t>. Without "
4661 "use of such a type, the declaration of B<signal>() is the somewhat harder "
4666 #: build/C/man2/signal.2:160
4669 "B<void ( *>I<signal>B<(int >I<signum>B<, void (*>I<handler>B<)(int)) ) "
4674 #: build/C/man2/signal.2:162
4680 #: build/C/man2/signal.2:174
4682 "The only portable use of B<signal>() is to set a signal's disposition to "
4683 "B<SIG_DFL> or B<SIG_IGN>. The semantics when using B<signal>() to "
4684 "establish a signal handler vary across systems (and POSIX.1 explicitly "
4685 "permits this variation); B<do not use it for this purpose.>"
4689 #: build/C/man2/signal.2:180
4691 "POSIX.1 solved the portability mess by specifying B<sigaction>(2), which "
4692 "provides explicit control of the semantics when a signal handler is invoked; "
4693 "use that interface instead of B<signal>()."
4697 #: build/C/man2/signal.2:193
4699 "In the original UNIX systems, when a handler that was established using "
4700 "B<signal>() was invoked by the delivery of a signal, the disposition of the "
4701 "signal would be reset to B<SIG_DFL>, and the system did not block delivery "
4702 "of further instances of the signal. System V also provides these semantics "
4703 "for B<signal>(). This was bad because the signal might be delivered again "
4704 "before the handler had a chance to reestablish itself. Furthermore, rapid "
4705 "deliveries of the same signal could result in recursive invocations of the "
4710 #: build/C/man2/signal.2:203
4712 "BSD improved on this situation by changing the semantics of signal handling "
4713 "(but, unfortunately, silently changed the semantics when establishing a "
4714 "handler with B<signal>()). On BSD, when a signal handler is invoked, the "
4715 "signal disposition is not reset, and further instances of the signal are "
4716 "blocked from being delivered while the handler is executing."
4720 #: build/C/man2/signal.2:205
4721 msgid "The situation on Linux is as follows:"
4725 #: build/C/man2/signal.2:209
4726 msgid "The kernel's B<signal>() system call provides System V semantics."
4730 #: build/C/man2/signal.2:225
4732 "By default, in glibc 2 and later, the B<signal>() wrapper function does not "
4733 "invoke the kernel system call. Instead, it calls B<sigaction>(2) using "
4734 "flags that supply BSD semantics. This default behavior is provided as long "
4735 "as the B<_BSD_SOURCE> feature test macro is defined. By default, "
4736 "B<_BSD_SOURCE> is defined; it is also implicitly defined if one defines "
4737 "B<_GNU_SOURCE>, and can of course be explicitly defined."
4741 #. System V semantics are also provided if one uses the separate
4742 #. .BR sysv_signal (3)
4745 #: build/C/man2/signal.2:248
4747 "On glibc 2 and later, if the B<_BSD_SOURCE> feature test macro is not "
4748 "defined, then B<signal>() provides System V semantics. (The default "
4749 "implicit definition of B<_BSD_SOURCE> is not provided if one invokes "
4750 "B<gcc>(1) in one of its standard modes (I<-std=xxx> or I<-ansi>) or "
4751 "defines various other feature test macros such as B<_POSIX_SOURCE>, "
4752 "B<_XOPEN_SOURCE>, or B<_SVID_SOURCE>; see B<feature_test_macros>(7).)"
4756 #: build/C/man2/signal.2:259
4758 "The B<signal>() function in Linux libc4 and libc5 provide System V "
4759 "semantics. If one on a libc5 system includes I<E<lt>bsd/signal.hE<gt>> "
4760 "instead of I<E<lt>signal.hE<gt>>, then B<signal>() provides BSD semantics."
4764 #: build/C/man2/signal.2:277
4766 "B<kill>(1), B<alarm>(2), B<kill>(2), B<killpg>(2), B<pause>(2), "
4767 "B<sigaction>(2), B<signalfd>(2), B<sigpending>(2), B<sigprocmask>(2), "
4768 "B<sigsuspend>(2), B<bsd_signal>(3), B<raise>(3), B<siginterrupt>(3), "
4769 "B<sigqueue>(3), B<sigsetops>(3), B<sigvec>(3), B<sysv_signal>(3), "
4774 #: build/C/man7/signal.7:47
4775 msgid "signal - overview of signals"
4779 #: build/C/man7/signal.7:50
4781 "Linux supports both POSIX reliable signals (hereinafter \"standard "
4782 "signals\") and POSIX real-time signals."
4786 #: build/C/man7/signal.7:50
4788 msgid "Signal Dispositions"
4792 #: build/C/man7/signal.7:55
4794 "Each signal has a current I<disposition>, which determines how the process "
4795 "behaves when it is delivered the signal."
4799 #: build/C/man7/signal.7:58
4801 "The entries in the \"Action\" column of the tables below specify the default "
4802 "disposition for each signal, as follows:"
4806 #: build/C/man7/signal.7:58
4812 #: build/C/man7/signal.7:60
4813 msgid "Default action is to terminate the process."
4817 #: build/C/man7/signal.7:60
4823 #: build/C/man7/signal.7:62
4824 msgid "Default action is to ignore the signal."
4828 #: build/C/man7/signal.7:62
4834 #: build/C/man7/signal.7:65
4835 msgid "Default action is to terminate the process and dump core (see B<core>(5))."
4839 #: build/C/man7/signal.7:65
4845 #: build/C/man7/signal.7:67
4846 msgid "Default action is to stop the process."
4850 #: build/C/man7/signal.7:67
4856 #: build/C/man7/signal.7:69
4857 msgid "Default action is to continue the process if it is currently stopped."
4861 #: build/C/man7/signal.7:91
4863 "A process can change the disposition of a signal using B<sigaction>(2) or "
4864 "B<signal>(2). (The latter is less portable when establishing a signal "
4865 "handler; see B<signal>(2) for details.) Using these system calls, a "
4866 "process can elect one of the following behaviors to occur on delivery of the "
4867 "signal: perform the default action; ignore the signal; or catch the signal "
4868 "with a I<signal handler>, a programmer-defined function that is "
4869 "automatically invoked when the signal is delivered. (By default, the signal "
4870 "handler is invoked on the normal process stack. It is possible to arrange "
4871 "that the signal handler uses an alternate stack; see B<sigaltstack>(2) for "
4872 "a discussion of how to do this and when it might be useful.)"
4876 #: build/C/man7/signal.7:95
4878 "The signal disposition is a per-process attribute: in a multithreaded "
4879 "application, the disposition of a particular signal is the same for all "
4884 #: build/C/man7/signal.7:103
4886 msgid "Sending a Signal"
4890 #: build/C/man7/signal.7:106
4892 "The following system calls and library functions allow the caller to send a "
4897 #: build/C/man7/signal.7:106
4903 #: build/C/man7/signal.7:109
4904 msgid "Sends a signal to the calling thread."
4908 #: build/C/man7/signal.7:109
4914 #: build/C/man7/signal.7:114
4916 "Sends a signal to a specified process, to all members of a specified process "
4917 "group, or to all processes on the system."
4921 #: build/C/man7/signal.7:114
4923 msgid "B<killpg>(2)"
4927 #: build/C/man7/signal.7:117
4928 msgid "Sends a signal to all of the members of a specified process group."
4932 #: build/C/man7/signal.7:117
4934 msgid "B<pthread_kill>(3)"
4938 #: build/C/man7/signal.7:121
4940 "Sends a signal to a specified POSIX thread in the same process as the "
4945 #: build/C/man7/signal.7:121
4947 msgid "B<tgkill>(2)"
4951 #: build/C/man7/signal.7:126
4953 "Sends a signal to a specified thread within a specific process. (This is "
4954 "the system call used to implement B<pthread_kill>(3).)"
4958 #: build/C/man7/signal.7:129
4959 msgid "Sends a real-time signal with accompanying data to a specified process."
4963 #: build/C/man7/signal.7:129
4965 msgid "Waiting for a Signal to be Caught"
4969 #: build/C/man7/signal.7:133
4971 "The following system calls suspend execution of the calling process or "
4972 "thread until a signal is caught (or an unhandled signal terminates the "
4977 #: build/C/man7/signal.7:133
4983 #: build/C/man7/signal.7:136
4984 msgid "Suspends execution until any signal is caught."
4988 #: build/C/man7/signal.7:136
4990 msgid "B<sigsuspend>(2)"
4994 #: build/C/man7/signal.7:140
4996 "Temporarily changes the signal mask (see below) and suspends execution until "
4997 "one of the unmasked signals is caught."
5001 #: build/C/man7/signal.7:140
5003 msgid "Synchronously Accepting a Signal"
5007 #: build/C/man7/signal.7:147
5009 "Rather than asynchronously catching a signal via a signal handler, it is "
5010 "possible to synchronously accept the signal, that is, to block execution "
5011 "until the signal is delivered, at which point the kernel returns information "
5012 "about the signal to the caller. There are two general ways to do this:"
5016 #: build/C/man7/signal.7:155
5018 "B<sigwaitinfo>(2), B<sigtimedwait>(2), and B<sigwait>(3) suspend execution "
5019 "until one of the signals in a specified set is delivered. Each of these "
5020 "calls returns information about the delivered signal."
5024 #: build/C/man7/signal.7:168
5026 "B<signalfd>(2) returns a file descriptor that can be used to read "
5027 "information about signals that are delivered to the caller. Each B<read>(2) "
5028 "from this file descriptor blocks until one of the signals in the set "
5029 "specified in the B<signalfd>(2) call is delivered to the caller. The "
5030 "buffer returned by B<read>(2) contains a structure describing the signal."
5034 #: build/C/man7/signal.7:168
5036 msgid "Signal Mask and Pending Signals"
5040 #: build/C/man7/signal.7:175
5042 "A signal may be I<blocked>, which means that it will not be delivered until "
5043 "it is later unblocked. Between the time when it is generated and when it is "
5044 "delivered a signal is said to be I<pending>."
5048 #: build/C/man7/signal.7:184
5050 "Each thread in a process has an independent I<signal mask>, which indicates "
5051 "the set of signals that the thread is currently blocking. A thread can "
5052 "manipulate its signal mask using B<pthread_sigmask>(3). In a traditional "
5053 "single-threaded application, B<sigprocmask>(2) can be used to manipulate "
5058 #: build/C/man7/signal.7:190 build/C/man2/sigprocmask.2:121
5060 "A child created via B<fork>(2) inherits a copy of its parent's signal mask; "
5061 "the signal mask is preserved across B<execve>(2)."
5065 #: build/C/man7/signal.7:207
5067 "A signal may be generated (and thus pending) for a process as a whole "
5068 "(e.g., when sent using B<kill>(2)) or for a specific thread (e.g., certain "
5069 "signals, such as B<SIGSEGV> and B<SIGFPE>, generated as a consequence of "
5070 "executing a specific machine-language instruction are thread directed, as "
5071 "are signals targeted at a specific thread using B<pthread_kill>(3)). A "
5072 "process-directed signal may be delivered to any one of the threads that does "
5073 "not currently have the signal blocked. If more than one of the threads has "
5074 "the signal unblocked, then the kernel chooses an arbitrary thread to which "
5075 "to deliver the signal."
5079 #: build/C/man7/signal.7:214
5081 "A thread can obtain the set of signals that it currently has pending using "
5082 "B<sigpending>(2). This set will consist of the union of the set of pending "
5083 "process-directed signals and the set of signals pending for the calling "
5088 #: build/C/man7/signal.7:220 build/C/man2/sigpending.2:76
5090 "A child created via B<fork>(2) initially has an empty pending signal set; "
5091 "the pending signal set is preserved across an B<execve>(2)."
5095 #: build/C/man7/signal.7:220
5097 msgid "Standard Signals"
5100 #. parisc is a law unto itself
5102 #: build/C/man7/signal.7:230
5104 "Linux supports the standard signals listed below. Several signal numbers "
5105 "are architecture-dependent, as indicated in the \"Value\" column. (Where "
5106 "three values are given, the first one is usually valid for alpha and sparc, "
5107 "the middle one for ix86, ia64, ppc, s390, arm and sh, and the last one for "
5108 "mips. A - denotes that a signal is absent on the corresponding "
5113 #: build/C/man7/signal.7:232
5114 msgid "First the signals described in the original POSIX.1-1990 standard."
5118 #: build/C/man7/signal.7:236 build/C/man7/signal.7:272 build/C/man7/signal.7:301
5120 msgid "Signal\tValue\tAction\tComment\n"
5124 #: build/C/man7/signal.7:237
5126 msgid "SIGHUP\t\\01\tTerm\tHangup detected on controlling terminal\n"
5130 #: build/C/man7/signal.7:238
5132 msgid "\t\t\tor death of controlling process\n"
5136 #: build/C/man7/signal.7:239
5138 msgid "SIGINT\t\\02\tTerm\tInterrupt from keyboard\n"
5142 #: build/C/man7/signal.7:240
5144 msgid "SIGQUIT\t\\03\tCore\tQuit from keyboard\n"
5148 #: build/C/man7/signal.7:241
5150 msgid "SIGILL\t\\04\tCore\tIllegal Instruction\n"
5154 #: build/C/man7/signal.7:242
5156 msgid "SIGABRT\t\\06\tCore\tAbort signal from B<abort>(3)\n"
5160 #: build/C/man7/signal.7:243
5162 msgid "SIGFPE\t\\08\tCore\tFloating point exception\n"
5166 #: build/C/man7/signal.7:244
5168 msgid "SIGKILL\t\\09\tTerm\tKill signal\n"
5172 #: build/C/man7/signal.7:245
5174 msgid "SIGSEGV\t11\tCore\tInvalid memory reference\n"
5178 #: build/C/man7/signal.7:246
5180 msgid "SIGPIPE\t13\tTerm\tBroken pipe: write to pipe with no\n"
5184 #: build/C/man7/signal.7:247
5186 msgid "\t\t\treaders\n"
5190 #: build/C/man7/signal.7:248
5192 msgid "SIGALRM\t14\tTerm\tTimer signal from B<alarm>(2)\n"
5196 #: build/C/man7/signal.7:249
5198 msgid "SIGTERM\t15\tTerm\tTermination signal\n"
5202 #: build/C/man7/signal.7:250
5204 msgid "SIGUSR1\t30,10,16\tTerm\tUser-defined signal 1\n"
5208 #: build/C/man7/signal.7:251
5210 msgid "SIGUSR2\t31,12,17\tTerm\tUser-defined signal 2\n"
5214 #: build/C/man7/signal.7:252
5216 msgid "SIGCHLD\t20,17,18\tIgn\tChild stopped or terminated\n"
5220 #: build/C/man7/signal.7:253
5222 msgid "SIGCONT\t19,18,25\tCont\tContinue if stopped\n"
5226 #: build/C/man7/signal.7:254
5228 msgid "SIGSTOP\t17,19,23\tStop\tStop process\n"
5232 #: build/C/man7/signal.7:255
5234 msgid "SIGTSTP\t18,20,24\tStop\tStop typed at tty\n"
5238 #: build/C/man7/signal.7:256
5240 msgid "SIGTTIN\t21,21,26\tStop\ttty input for background process\n"
5244 #: build/C/man7/signal.7:257
5246 msgid "SIGTTOU\t22,22,27\tStop\ttty output for background process\n"
5250 #: build/C/man7/signal.7:265
5251 msgid "The signals B<SIGKILL> and B<SIGSTOP> cannot be caught, blocked, or ignored."
5255 #: build/C/man7/signal.7:268
5257 "Next the signals not in the POSIX.1-1990 standard but described in SUSv2 and "
5262 #: build/C/man7/signal.7:273
5264 msgid "SIGBUS\t10,7,10\tCore\tBus error (bad memory access)\n"
5268 #: build/C/man7/signal.7:274
5270 msgid "SIGPOLL\t\tTerm\tPollable event (Sys V).\n"
5274 #: build/C/man7/signal.7:275
5276 msgid "\t\t\tSynonym for B<SIGIO>\n"
5280 #: build/C/man7/signal.7:276
5282 msgid "SIGPROF\t27,27,29\tTerm\tProfiling timer expired\n"
5286 #: build/C/man7/signal.7:277
5288 msgid "SIGSYS\t12,31,12\tCore\tBad argument to routine (SVr4)\n"
5292 #: build/C/man7/signal.7:278
5294 msgid "SIGTRAP\t5\tCore\tTrace/breakpoint trap\n"
5298 #: build/C/man7/signal.7:279
5300 msgid "SIGURG\t16,23,21\tIgn\tUrgent condition on socket (4.2BSD)\n"
5304 #: build/C/man7/signal.7:280
5306 msgid "SIGVTALRM\t26,26,28\tTerm\tVirtual alarm clock (4.2BSD)\n"
5310 #: build/C/man7/signal.7:281
5312 msgid "SIGXCPU\t24,24,30\tCore\tCPU time limit exceeded (4.2BSD)\n"
5316 #: build/C/man7/signal.7:282
5318 msgid "SIGXFSZ\t25,25,31\tCore\tFile size limit exceeded (4.2BSD)\n"
5322 #: build/C/man7/signal.7:295
5324 "Up to and including Linux 2.2, the default behavior for B<SIGSYS>, "
5325 "B<SIGXCPU>, B<SIGXFSZ>, and (on architectures other than SPARC and MIPS) "
5326 "B<SIGBUS> was to terminate the process (without a core dump). (On some "
5327 "other UNIX systems the default action for B<SIGXCPU> and B<SIGXFSZ> is to "
5328 "terminate the process without a core dump.) Linux 2.4 conforms to the "
5329 "POSIX.1-2001 requirements for these signals, terminating the process with a "
5334 #: build/C/man7/signal.7:297
5335 msgid "Next various other signals."
5339 #: build/C/man7/signal.7:302
5341 msgid "SIGIOT\t6\tCore\tIOT trap. A synonym for B<SIGABRT>\n"
5345 #: build/C/man7/signal.7:303
5347 msgid "SIGEMT\t7,-,7\tTerm\n"
5351 #: build/C/man7/signal.7:304
5353 msgid "SIGSTKFLT\t-,16,-\tTerm\tStack fault on coprocessor (unused)\n"
5357 #: build/C/man7/signal.7:305
5359 msgid "SIGIO\t23,29,22\tTerm\tI/O now possible (4.2BSD)\n"
5363 #: build/C/man7/signal.7:306
5365 msgid "SIGCLD\t-,-,18\tIgn\tA synonym for B<SIGCHLD>\n"
5369 #: build/C/man7/signal.7:307
5371 msgid "SIGPWR\t29,30,19\tTerm\tPower failure (System V)\n"
5375 #: build/C/man7/signal.7:308
5377 msgid "SIGINFO\t29,-,-\t\tA synonym for B<SIGPWR>\n"
5381 #: build/C/man7/signal.7:309
5383 msgid "SIGLOST\t-,-,-\tTerm\tFile lock lost\n"
5387 #: build/C/man7/signal.7:310
5389 msgid "SIGWINCH\t28,28,20\tIgn\tWindow resize signal (4.3BSD, Sun)\n"
5393 #: build/C/man7/signal.7:311
5395 msgid "SIGUNUSED\t-,31,-\tCore\tSynonymous with B<SIGSYS>\n"
5399 #: build/C/man7/signal.7:321
5400 msgid "(Signal 29 is B<SIGINFO> / B<SIGPWR> on an alpha but B<SIGLOST> on a sparc.)"
5404 #: build/C/man7/signal.7:327
5406 "B<SIGEMT> is not specified in POSIX.1-2001, but nevertheless appears on most "
5407 "other UNIX systems, where its default action is typically to terminate the "
5408 "process with a core dump."
5412 #: build/C/man7/signal.7:331
5414 "B<SIGPWR> (which is not specified in POSIX.1-2001) is typically ignored by "
5415 "default on those other UNIX systems where it appears."
5419 #: build/C/man7/signal.7:335
5421 "B<SIGIO> (which is not specified in POSIX.1-2001) is ignored by default on "
5422 "several other UNIX systems."
5425 #. parisc is the only exception: SIGSYS is 12, SIGUNUSED is 31
5427 #: build/C/man7/signal.7:342
5429 "Where defined, B<SIGUNUSED> is synonymous with B<SIGSYS> on most "
5434 #: build/C/man7/signal.7:342
5436 msgid "Real-time Signals"
5440 #: build/C/man7/signal.7:352
5442 "Linux supports real-time signals as originally defined in the POSIX.1b "
5443 "real-time extensions (and now included in POSIX.1-2001). The range of "
5444 "supported real-time signals is defined by the macros B<SIGRTMIN> and "
5445 "B<SIGRTMAX>. POSIX.1-2001 requires that an implementation support at least "
5446 "B<_POSIX_RTSIG_MAX> (8) real-time signals."
5450 #: build/C/man7/signal.7:374
5452 "The Linux kernel supports a range of 32 different real-time signals, "
5453 "numbered 33 to 64. However, the glibc POSIX threads implementation "
5454 "internally uses two (for NPTL) or three (for LinuxThreads) real-time signals "
5455 "(see B<pthreads>(7)), and adjusts the value of B<SIGRTMIN> suitably (to 34 "
5456 "or 35). Because the range of available real-time signals varies according "
5457 "to the glibc threading implementation (and this variation can occur at run "
5458 "time according to the available kernel and glibc), and indeed the range of "
5459 "real-time signals varies across UNIX systems, programs should I<never refer "
5460 "to real-time signals using hard-coded numbers>, but instead should always "
5461 "refer to real-time signals using the notation B<SIGRTMIN>+n, and include "
5462 "suitable (run-time) checks that B<SIGRTMIN>+n does not exceed B<SIGRTMAX>."
5466 #: build/C/man7/signal.7:378
5468 "Unlike standard signals, real-time signals have no predefined meanings: the "
5469 "entire set of real-time signals can be used for application-defined "
5474 #: build/C/man7/signal.7:381
5476 "The default action for an unhandled real-time signal is to terminate the "
5477 "receiving process."
5481 #: build/C/man7/signal.7:383
5482 msgid "Real-time signals are distinguished by the following:"
5486 #: build/C/man7/signal.7:387
5488 "Multiple instances of real-time signals can be queued. By contrast, if "
5489 "multiple instances of a standard signal are delivered while that signal is "
5490 "currently blocked, then only one instance is queued."
5494 #: build/C/man7/signal.7:407
5496 "If the signal is sent using B<sigqueue>(3), an accompanying value (either an "
5497 "integer or a pointer) can be sent with the signal. If the receiving process "
5498 "establishes a handler for this signal using the B<SA_SIGINFO> flag to "
5499 "B<sigaction>(2) then it can obtain this data via the I<si_value> field of "
5500 "the I<siginfo_t> structure passed as the second argument to the handler. "
5501 "Furthermore, the I<si_pid> and I<si_uid> fields of this structure can be "
5502 "used to obtain the PID and real user ID of the process sending the signal."
5506 #: build/C/man7/signal.7:416
5508 "Real-time signals are delivered in a guaranteed order. Multiple real-time "
5509 "signals of the same type are delivered in the order they were sent. If "
5510 "different real-time signals are sent to a process, they are delivered "
5511 "starting with the lowest-numbered signal. (I.e., low-numbered signals have "
5512 "highest priority.) By contrast, if multiple standard signals are pending "
5513 "for a process, the order in which they are delivered is unspecified."
5517 #: build/C/man7/signal.7:421
5519 "If both standard and real-time signals are pending for a process, POSIX "
5520 "leaves it unspecified which is delivered first. Linux, like many other "
5521 "implementations, gives priority to standard signals in this case."
5525 #: build/C/man7/signal.7:444
5527 "According to POSIX, an implementation should permit at least "
5528 "B<_POSIX_SIGQUEUE_MAX> (32) real-time signals to be queued to a process. "
5529 "However, Linux does things differently. In kernels up to and including "
5530 "2.6.7, Linux imposes a system-wide limit on the number of queued real-time "
5531 "signals for all processes. This limit can be viewed and (with privilege) "
5532 "changed via the I</proc/sys/kernel/rtsig-max> file. A related file, "
5533 "I</proc/sys/kernel/rtsig-nr>, can be used to find out how many real-time "
5534 "signals are currently queued. In Linux 2.6.8, these I</proc> interfaces "
5535 "were replaced by the B<RLIMIT_SIGPENDING> resource limit, which specifies a "
5536 "per-user limit for queued signals; see B<setrlimit>(2) for further details."
5540 #: build/C/man7/signal.7:444
5542 msgid "Async-signal-safe functions"
5546 #: build/C/man7/signal.7:453
5548 "A signal handler function must be very careful, since processing elsewhere "
5549 "may be interrupted at some arbitrary point in the execution of the program. "
5550 "POSIX has the concept of \"safe function\". If a signal interrupts the "
5551 "execution of an unsafe function, and I<handler> calls an unsafe function, "
5552 "then the behavior of the program is undefined."
5556 #: build/C/man7/signal.7:457
5558 "POSIX.1-2004 (also known as POSIX.1-2001 Technical Corrigendum 2) requires "
5559 "an implementation to guarantee that the following functions can be safely "
5560 "called inside a signal handler:"
5564 #: build/C/man7/signal.7:578
5624 "posix_trace_event()\n"
5674 "timer_getoverrun()\n"
5688 #: build/C/man7/signal.7:583
5690 "POSIX.1-2008 removes fpathconf(), pathconf(), and sysconf() from the above "
5691 "list, and adds the following functions:"
5695 #: build/C/man7/signal.7:606
5721 #: build/C/man7/signal.7:608
5723 msgid "Interruption of System Calls and Library Functions by Signal Handlers"
5727 #: build/C/man7/signal.7:611
5729 "If a signal handler is invoked while a system call or library function call "
5730 "is blocked, then either:"
5734 #: build/C/man7/signal.7:613
5735 msgid "the call is automatically restarted after the signal handler returns; or"
5739 #: build/C/man7/signal.7:616
5740 msgid "the call fails with the error B<EINTR>."
5744 #: build/C/man7/signal.7:624
5746 "Which of these two behaviors occurs depends on the interface and whether or "
5747 "not the signal handler was established using the B<SA_RESTART> flag (see "
5748 "B<sigaction>(2)). The details vary across UNIX systems; below, the details "
5752 #. The following system calls use ERESTARTSYS,
5753 #. so that they are restartable
5755 #: build/C/man7/signal.7:633
5757 "If a blocked call to one of the following interfaces is interrupted by a "
5758 "signal handler, then the call will be automatically restarted after the "
5759 "signal handler returns if the B<SA_RESTART> flag was used; otherwise the "
5760 "call will fail with the error B<EINTR>:"
5764 #: build/C/man7/signal.7:649
5766 "B<read>(2), B<readv>(2), B<write>(2), B<writev>(2), and B<ioctl>(2) calls "
5767 "on \"slow\" devices. A \"slow\" device is one where the I/O call may block "
5768 "for an indefinite time, for example, a terminal, pipe, or socket. (A disk "
5769 "is not a slow device according to this definition.) If an I/O call on a "
5770 "slow device has already transferred some data by the time it is interrupted "
5771 "by a signal handler, then the call will return a success status (normally, "
5772 "the number of bytes transferred)."
5776 #: build/C/man7/signal.7:653
5777 msgid "B<open>(2), if it can block (e.g., when opening a FIFO; see B<fifo>(7))."
5781 #: build/C/man7/signal.7:660
5782 msgid "B<wait>(2), B<wait3>(2), B<wait4>(2), B<waitid>(2), and B<waitpid>(2)."
5785 #. If a timeout (setsockopt()) is in effect on the socket, then these
5786 #. system calls switch to using EINTR. Consequently, they and are not
5787 #. automatically restarted, and they show the stop/cont behavior
5788 #. described below. (Verified from 2.6.26 source, and by experiment; mtk)
5790 #: build/C/man7/signal.7:676
5792 "Socket interfaces: B<accept>(2), B<connect>(2), B<recv>(2), B<recvfrom>(2), "
5793 "B<recvmsg>(2), B<send>(2), B<sendto>(2), and B<sendmsg>(2), unless a timeout "
5794 "has been set on the socket (see below)."
5798 #: build/C/man7/signal.7:682
5799 msgid "File locking interfaces: B<flock>(2) and B<fcntl>(2) B<F_SETLKW>."
5803 #: build/C/man7/signal.7:689
5805 "POSIX message queue interfaces: B<mq_receive>(3), B<mq_timedreceive>(3), "
5806 "B<mq_send>(3), and B<mq_timedsend>(3)."
5810 #: build/C/man7/signal.7:694
5812 "B<futex>(2) B<FUTEX_WAIT> (since Linux 2.6.22; beforehand, always failed "
5817 #: build/C/man7/signal.7:701
5819 "POSIX semaphore interfaces: B<sem_wait>(3) and B<sem_timedwait>(3) (since "
5820 "Linux 2.6.22; beforehand, always failed with B<EINTR>)."
5823 #. These are the system calls that give EINTR or ERESTARTNOHAND
5824 #. on interruption by a signal handler.
5826 #: build/C/man7/signal.7:712
5828 "The following interfaces are never restarted after being interrupted by a "
5829 "signal handler, regardless of the use of B<SA_RESTART>; they always fail "
5830 "with the error B<EINTR> when interrupted by a signal handler:"
5834 #: build/C/man7/signal.7:732 build/C/man7/signal.7:806
5836 "Socket interfaces, when a timeout has been set on the socket using "
5837 "B<setsockopt>(2): B<accept>(2), B<recv>(2), B<recvfrom>(2), and "
5838 "B<recvmsg>(2), if a receive timeout (B<SO_RCVTIMEO>) has been set; "
5839 "B<connect>(2), B<send>(2), B<sendto>(2), and B<sendmsg>(2), if a send "
5840 "timeout (B<SO_SNDTIMEO>) has been set."
5844 #: build/C/man7/signal.7:739
5846 "Interfaces used to wait for signals: B<pause>(2), B<sigsuspend>(2), "
5847 "B<sigtimedwait>(2), and B<sigwaitinfo>(2)."
5851 #: build/C/man7/signal.7:748
5853 "File descriptor multiplexing interfaces: B<epoll_wait>(2), "
5854 "B<epoll_pwait>(2), B<poll>(2), B<ppoll>(2), B<select>(2), and B<pselect>(2)."
5857 #. On some other systems, SA_RESTART does restart these system calls
5859 #: build/C/man7/signal.7:756
5861 "System V IPC interfaces: B<msgrcv>(2), B<msgsnd>(2), B<semop>(2), and "
5866 #: build/C/man7/signal.7:762
5867 msgid "Sleep interfaces: B<clock_nanosleep>(2), B<nanosleep>(2), and B<usleep>(3)."
5871 #: build/C/man7/signal.7:767 build/C/man7/signal.7:820
5872 msgid "B<read>(2) from an B<inotify>(7) file descriptor."
5876 #: build/C/man7/signal.7:769
5877 msgid "B<io_getevents>(2)."
5881 #: build/C/man7/signal.7:775
5883 "The B<sleep>(3) function is also never restarted if interrupted by a "
5884 "handler, but gives a success return: the number of seconds remaining to "
5889 #: build/C/man7/signal.7:775
5891 msgid "Interruption of System Calls and Library Functions by Stop Signals"
5895 #: build/C/man7/signal.7:784
5897 "On Linux, even in the absence of signal handlers, certain blocking "
5898 "interfaces can fail with the error B<EINTR> after the process is stopped by "
5899 "one of the stop signals and then resumed via B<SIGCONT>. This behavior is "
5900 "not sanctioned by POSIX.1, and doesn't occur on other systems."
5904 #: build/C/man7/signal.7:786
5905 msgid "The Linux interfaces that display this behavior are:"
5909 #: build/C/man7/signal.7:809
5910 msgid "B<epoll_wait>(2), B<epoll_pwait>(2)."
5914 #: build/C/man7/signal.7:812
5915 msgid "B<semop>(2), B<semtimedop>(2)."
5919 #: build/C/man7/signal.7:815
5920 msgid "B<sigtimedwait>(2), B<sigwaitinfo>(2)."
5924 #: build/C/man7/signal.7:826
5926 "Linux 2.6.21 and earlier: B<futex>(2) B<FUTEX_WAIT>, B<sem_timedwait>(3), "
5931 #: build/C/man7/signal.7:830
5932 msgid "Linux 2.6.8 and earlier: B<msgrcv>(2), B<msgsnd>(2)."
5936 #: build/C/man7/signal.7:833
5937 msgid "Linux 2.4 and earlier: B<nanosleep>(2)."
5941 #: build/C/man7/signal.7:836
5942 msgid "POSIX.1, except as noted."
5946 #: build/C/man7/signal.7:845
5948 "B<SIGIO> and B<SIGLOST> have the same value. The latter is commented out in "
5949 "the kernel source, but the build process of some software still thinks that "
5950 "signal 29 is B<SIGLOST>."
5954 #: build/C/man7/signal.7:877
5956 "B<kill>(1), B<getrlimit>(2), B<kill>(2), B<killpg>(2), "
5957 "B<rt_sigqueueinfo>(2), B<setitimer>(2), B<setrlimit>(2), B<sgetmask>(2), "
5958 "B<sigaction>(2), B<sigaltstack>(2), B<signal>(2), B<signalfd>(2), "
5959 "B<sigpending>(2), B<sigprocmask>(2), B<sigsuspend>(2), B<sigwaitinfo>(2), "
5960 "B<abort>(3), B<bsd_signal>(3), B<longjmp>(3), B<raise>(3), "
5961 "B<pthread_sigqueue>(3), B<sigqueue>(3), B<sigset>(3), B<sigsetops>(3), "
5962 "B<sigvec>(3), B<sigwait>(3), B<strsignal>(3), B<sysv_signal>(3), B<core>(5), "
5963 "B<proc>(5), B<pthreads>(7), B<sigevent>(7)"
5967 #: build/C/man2/signalfd.2:19
5973 #: build/C/man2/signalfd.2:19
5979 #: build/C/man2/signalfd.2:22
5980 msgid "signalfd - create a file descriptor for accepting signals"
5984 #: build/C/man2/signalfd.2:24
5985 msgid "B<#include E<lt>sys/signalfd.hE<gt>>"
5989 #: build/C/man2/signalfd.2:26
5990 msgid "B<int signalfd(int >I<fd>B<, const sigset_t *>I<mask>B<, int >I<flags>B<);>"
5994 #: build/C/man2/signalfd.2:37
5996 "B<signalfd>() creates a file descriptor that can be used to accept signals "
5997 "targeted at the caller. This provides an alternative to the use of a signal "
5998 "handler or B<sigwaitinfo>(2), and has the advantage that the file descriptor "
5999 "may be monitored by B<select>(2), B<poll>(2), and B<epoll>(7)."
6003 #: build/C/man2/signalfd.2:57
6005 "The I<mask> argument specifies the set of signals that the caller wishes to "
6006 "accept via the file descriptor. This argument is a signal set whose "
6007 "contents can be initialized using the macros described in B<sigsetops>(3). "
6008 "Normally, the set of signals to be received via the file descriptor should "
6009 "be blocked using B<sigprocmask>(2), to prevent the signals being handled "
6010 "according to their default dispositions. It is not possible to receive "
6011 "B<SIGKILL> or B<SIGSTOP> signals via a signalfd file descriptor; these "
6012 "signals are silently ignored if specified in I<mask>."
6016 #: build/C/man2/signalfd.2:71
6018 "If the I<fd> argument is -1, then the call creates a new file descriptor and "
6019 "associates the signal set specified in I<mask> with that descriptor. If "
6020 "I<fd> is not -1, then it must specify a valid existing signalfd file "
6021 "descriptor, and I<mask> is used to replace the signal set associated with "
6026 #: build/C/man2/signalfd.2:76
6028 "Starting with Linux 2.6.27, the following values may be bitwise ORed in "
6029 "I<flags> to change the behaviour of B<signalfd>():"
6033 #: build/C/man2/signalfd.2:76
6035 msgid "B<SFD_NONBLOCK>"
6039 #: build/C/man2/signalfd.2:84
6041 msgid "B<SFD_CLOEXEC>"
6045 #: build/C/man2/signalfd.2:101
6047 "B<signalfd>() returns a file descriptor that supports the following "
6052 #: build/C/man2/signalfd.2:120
6054 "If one or more of the signals specified in I<mask> is pending for the "
6055 "process, then the buffer supplied to B<read>(2) is used to return one or "
6056 "more I<signalfd_siginfo> structures (see below) that describe the signals. "
6057 "The B<read>(2) returns information for as many signals as are pending and "
6058 "will fit in the supplied buffer. The buffer must be at least "
6059 "I<sizeof(struct signalfd_siginfo)> bytes. The return value of the "
6060 "B<read>(2) is the total number of bytes read."
6064 #: build/C/man2/signalfd.2:128
6066 "As a consequence of the B<read>(2), the signals are consumed, so that they "
6067 "are no longer pending for the process (i.e., will not be caught by signal "
6068 "handlers, and cannot be accepted using B<sigwaitinfo>(2))."
6072 #: build/C/man2/signalfd.2:139
6074 "If none of the signals in I<mask> is pending for the process, then the "
6075 "B<read>(2) either blocks until one of the signals in I<mask> is generated "
6076 "for the process, or fails with the error B<EAGAIN> if the file descriptor "
6077 "has been made nonblocking."
6081 #: build/C/man2/signalfd.2:152
6083 "The file descriptor is readable (the B<select>(2) I<readfds> argument; the "
6084 "B<poll>(2) B<POLLIN> flag) if one or more of the signals in I<mask> is "
6085 "pending for the process."
6089 #: build/C/man2/signalfd.2:159
6091 "The signalfd file descriptor also supports the other file-descriptor "
6092 "multiplexing APIs: B<pselect>(2), B<ppoll>(2), and B<epoll>(7)."
6096 #: build/C/man2/signalfd.2:164
6098 "When the file descriptor is no longer required it should be closed. When "
6099 "all file descriptors associated with the same signalfd object have been "
6100 "closed, the resources for object are freed by the kernel."
6104 #: build/C/man2/signalfd.2:164
6106 msgid "The signalfd_siginfo structure"
6110 #: build/C/man2/signalfd.2:170
6112 "The format of the I<signalfd_siginfo> structure(s) returned by B<read>(2)s "
6113 "from a signalfd file descriptor is as follows:"
6116 #. ssi_trapno is unused on most arches
6118 #: build/C/man2/signalfd.2:195
6121 "struct signalfd_siginfo {\n"
6122 " uint32_t ssi_signo; /* Signal number */\n"
6123 " int32_t ssi_errno; /* Error number (unused) */\n"
6124 " int32_t ssi_code; /* Signal code */\n"
6125 " uint32_t ssi_pid; /* PID of sender */\n"
6126 " uint32_t ssi_uid; /* Real UID of sender */\n"
6127 " int32_t ssi_fd; /* File descriptor (SIGIO) */\n"
6128 " uint32_t ssi_tid; /* Kernel timer ID (POSIX timers)\n"
6129 " uint32_t ssi_band; /* Band event (SIGIO) */\n"
6130 " uint32_t ssi_overrun; /* POSIX timer overrun count */\n"
6131 " uint32_t ssi_trapno; /* Trap number that caused signal */\n"
6132 " int32_t ssi_status; /* Exit status or signal (SIGCHLD) */\n"
6133 " int32_t ssi_int; /* Integer sent by sigqueue(3) */\n"
6134 " uint64_t ssi_ptr; /* Pointer sent by sigqueue(3) */\n"
6135 " uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */\n"
6136 " uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */\n"
6137 " uint64_t ssi_addr; /* Address that generated signal\n"
6138 " (for hardware-generated signals) */\n"
6139 " uint8_t pad[I<X>]; /* Pad size to 128 bytes (allow for\n"
6140 " additional fields in the future) */\n"
6145 #: build/C/man2/signalfd.2:218
6147 "Each of the fields in this structure is analogous to the similarly named "
6148 "field in the I<siginfo_t> structure. The I<siginfo_t> structure is "
6149 "described in B<sigaction>(2). Not all fields in the returned "
6150 "I<signalfd_siginfo> structure will be valid for a specific signal; the set "
6151 "of valid fields can be determined from the value returned in the I<ssi_code> "
6152 "field. This field is the analog of the I<siginfo_t> I<si_code> field; see "
6153 "B<sigaction>(2) for details."
6157 #: build/C/man2/signalfd.2:218 build/C/man2/timerfd_create.2:268
6159 msgid "fork(2) semantics"
6163 #: build/C/man2/signalfd.2:226
6165 "After a B<fork>(2), the child inherits a copy of the signalfd file "
6166 "descriptor. A B<read>(2) from the file descriptor in the child will return "
6167 "information about signals queued to the child."
6171 #: build/C/man2/signalfd.2:226 build/C/man2/timerfd_create.2:280
6173 msgid "execve(2) semantics"
6177 #: build/C/man2/signalfd.2:238
6179 "Just like any other file descriptor, a signalfd file descriptor remains open "
6180 "across an B<execve>(2), unless it has been marked for close-on-exec (see "
6181 "B<fcntl>(2)). Any signals that were available for reading before the "
6182 "B<execve>(2) remain available to the newly loaded program. (This is "
6183 "analogous to traditional signal semantics, where a blocked signal that is "
6184 "pending remains pending across an B<execve>(2).)"
6188 #: build/C/man2/signalfd.2:238
6190 msgid "Thread semantics"
6194 #: build/C/man2/signalfd.2:248
6196 "The semantics of signalfd file descriptors in a multithreaded program mirror "
6197 "the standard semantics for signals. In other words, when a thread reads "
6198 "from a signalfd file descriptor, it will read the signals that are directed "
6199 "to the thread itself and the signals that are directed to the process (i.e., "
6200 "the entire thread group). (A thread will not be able to read signals that "
6201 "are directed to other threads in the process.)"
6205 #: build/C/man2/signalfd.2:262
6207 "On success, B<signalfd>() returns a signalfd file descriptor; this is "
6208 "either a new file descriptor (if I<fd> was -1), or I<fd> if I<fd> was a "
6209 "valid signalfd file descriptor. On error, -1 is returned and I<errno> is "
6210 "set to indicate the error."
6214 #: build/C/man2/signalfd.2:263 build/C/man2/timerfd_create.2:337
6220 #: build/C/man2/signalfd.2:268
6221 msgid "The I<fd> file descriptor is not a valid file descriptor."
6226 #. argument is not equal to
6227 #. .IR sizeof(sigset_t) ;
6229 #: build/C/man2/signalfd.2:276
6230 msgid "I<fd> is not a valid signalfd file descriptor."
6234 #: build/C/man2/signalfd.2:283 build/C/man2/timerfd_create.2:319
6235 msgid "I<flags> is invalid; or, in Linux 2.6.26 or earlier, I<flags> is nonzero."
6239 #: build/C/man2/signalfd.2:286 build/C/man2/timerfd_create.2:322
6240 msgid "The per-process limit of open file descriptors has been reached."
6244 #: build/C/man2/signalfd.2:296
6245 msgid "There was insufficient memory to create a new signalfd file descriptor."
6248 #. signalfd() is in glibc 2.7, but reportedly does not build
6250 #: build/C/man2/signalfd.2:304
6252 "B<signalfd>() is available on Linux since kernel 2.6.22. Working support "
6253 "is provided in glibc since version 2.8. The B<signalfd4>() system call "
6254 "(see NOTES) is available on Linux since kernel 2.6.27."
6258 #: build/C/man2/signalfd.2:309
6259 msgid "B<signalfd>() and B<signalfd4>() are Linux-specific."
6263 #: build/C/man2/signalfd.2:319
6265 "The underlying Linux system call requires an additional argument, I<size_t "
6266 "sizemask>, which specifies the size of the I<mask> argument. The glibc "
6267 "B<signalfd>() wrapper function does not include this argument, since it "
6268 "provides the required value for the underlying system call."
6272 #: build/C/man2/signalfd.2:333
6274 "A process can create multiple signalfd file descriptors. This makes it "
6275 "possible to accept different signals on different file descriptors. (This "
6276 "may be useful if monitoring the file descriptors using B<select>(2), "
6277 "B<poll>(2), or B<epoll>(7): the arrival of different signals will make "
6278 "different descriptors ready.) If a signal appears in the I<mask> of more "
6279 "than one of the file descriptors, then occurrences of that signal can be "
6280 "read (once) from any one of the descriptors."
6284 #: build/C/man2/signalfd.2:349
6286 "There are two underlying Linux system calls: B<signalfd>() and the more "
6287 "recent B<signalfd4>(). The former system call does not implement a I<flags> "
6288 "argument. The latter system call implements the I<flags> values described "
6289 "above. Starting with glibc 2.9, the B<signalfd>() wrapper function will "
6290 "use B<signalfd4>() where it is available."
6293 #. The fix also was put into 2.6.24.5
6295 #: build/C/man2/signalfd.2:357
6297 "In kernels before 2.6.25, the I<ssi_ptr> and I<ssi_int> fields are not "
6298 "filled in with the data accompanying a signal sent by B<sigqueue>(3)."
6302 #: build/C/man2/signalfd.2:367
6304 "The program below accepts the signals B<SIGINT> and B<SIGQUIT> via a "
6305 "signalfd file descriptor. The program terminates after accepting a "
6306 "B<SIGQUIT> signal. The following shell session demonstrates the use of the "
6311 #: build/C/man2/signalfd.2:378
6314 "$B< ./signalfd_demo>\n"
6315 "B<^C> # Control-C generates SIGINT\n"
6319 "B<^\\e> # Control-\\e generates SIGQUIT\n"
6325 #: build/C/man2/signalfd.2:388
6328 "#include E<lt>sys/signalfd.hE<gt>\n"
6329 "#include E<lt>signal.hE<gt>\n"
6330 "#include E<lt>unistd.hE<gt>\n"
6331 "#include E<lt>stdlib.hE<gt>\n"
6332 "#include E<lt>stdio.hE<gt>\n"
6336 #: build/C/man2/signalfd.2:399
6340 "main(int argc, char *argv[])\n"
6344 " struct signalfd_siginfo fdsi;\n"
6349 #: build/C/man2/signalfd.2:403
6352 " sigemptyset(&mask);\n"
6353 " sigaddset(&mask, SIGINT);\n"
6354 " sigaddset(&mask, SIGQUIT);\n"
6358 #: build/C/man2/signalfd.2:406
6361 " /* Block signals so that they aren\\(aqt handled\n"
6362 " according to their default dispositions */\n"
6366 #: build/C/man2/signalfd.2:409
6369 " if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)\n"
6370 " handle_error(\"sigprocmask\");\n"
6374 #: build/C/man2/signalfd.2:413
6377 " sfd = signalfd(-1, &mask, 0);\n"
6379 " handle_error(\"signalfd\");\n"
6383 #: build/C/man2/signalfd.2:418
6387 " s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));\n"
6388 " if (s != sizeof(struct signalfd_siginfo))\n"
6389 " handle_error(\"read\");\n"
6393 #: build/C/man2/signalfd.2:429
6396 " if (fdsi.ssi_signo == SIGINT) {\n"
6397 " printf(\"Got SIGINT\\en\");\n"
6398 " } else if (fdsi.ssi_signo == SIGQUIT) {\n"
6399 " printf(\"Got SIGQUIT\\en\");\n"
6400 " exit(EXIT_SUCCESS);\n"
6402 " printf(\"Read unexpected signal\\en\");\n"
6409 #: build/C/man2/signalfd.2:442
6411 "B<eventfd>(2), B<poll>(2), B<read>(2), B<select>(2), B<sigaction>(2), "
6412 "B<sigprocmask>(2), B<sigwaitinfo>(2), B<timerfd_create>(2), B<sigsetops>(3), "
6413 "B<sigwait>(3), B<epoll>(7), B<signal>(7)"
6417 #: build/C/man3/sigpause.3:23
6423 #: build/C/man3/sigpause.3:23
6429 #: build/C/man3/sigpause.3:26
6430 msgid "sigpause - atomically release blocked signals and wait for interrupt"
6434 #: build/C/man3/sigpause.3:31
6436 msgid "B<int sigpause(int >I<sigmask>B<); /* BSD */>\n"
6440 #: build/C/man3/sigpause.3:33
6442 msgid "B<int sigpause(int >I<sig>B<); /* System V / UNIX 95 */>\n"
6446 #: build/C/man3/sigpause.3:39
6447 msgid "Don't use this function. Use B<sigsuspend>(2) instead."
6451 #: build/C/man3/sigpause.3:46
6453 "The function B<sigpause>() is designed to wait for some signal. It changes "
6454 "the process's signal mask (set of blocked signals), and then waits for a "
6455 "signal to arrive. Upon arrival of a signal, the original signal mask is "
6460 #: build/C/man3/sigpause.3:54
6462 "If B<sigpause>() returns, it was interrupted by a signal and the return "
6463 "value is -1 with I<errno> set to B<EINTR>."
6467 #: build/C/man3/sigpause.3:58
6468 msgid "The System V version of B<sigpause>() is standardized in POSIX.1-2001."
6471 #. __xpg_sigpause: UNIX 95, spec 1170, SVID, SVr4, XPG
6473 #: build/C/man3/sigpause.3:75
6475 "The classical BSD version of this function appeared in 4.2BSD. It sets the "
6476 "process's signal mask to I<sigmask>. UNIX 95 standardized the incompatible "
6477 "System V version of this function, which removes only the specified signal "
6478 "I<sig> from the process's signal mask. The unfortunate situation with two "
6479 "incompatible functions with the same name was solved by the "
6480 "B<\\%sigsuspend>(2) function, that takes a I<sigset_t *> argument (instead "
6485 #: build/C/man3/sigpause.3:78
6487 "On Linux, this routine is a system call only on the Sparc (sparc64) "
6492 #: build/C/man3/sigpause.3:80
6493 msgid "Libc4 and libc5 only know about the BSD version."
6497 #. For the BSD version, one usually uses a zero
6499 #. to indicate that no signals are to be blocked.
6501 #: build/C/man3/sigpause.3:96
6503 "Glibc uses the BSD version if the B<_BSD_SOURCE> feature test macro is "
6504 "defined and none of B<_POSIX_SOURCE>, B<_POSIX_C_SOURCE>, B<_XOPEN_SOURCE>, "
6505 "B<_GNU_SOURCE>, or B<_SVID_SOURCE> is defined. Otherwise, the System V "
6510 #: build/C/man3/sigpause.3:103
6512 "B<kill>(2), B<sigaction>(2), B<sigprocmask>(2), B<sigsuspend>(2), "
6513 "B<sigblock>(3), B<sigvec>(3), B<feature_test_macros>(7)"
6517 #: build/C/man2/sigpending.2:27
6523 #: build/C/man2/sigpending.2:27
6529 #: build/C/man2/sigpending.2:30
6530 msgid "sigpending - examine pending signals"
6534 #: build/C/man2/sigpending.2:34
6535 msgid "B<int sigpending(sigset_t *>I<set>B<);>"
6539 #: build/C/man2/sigpending.2:43
6541 "B<sigpending>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
6546 #: build/C/man2/sigpending.2:51
6548 "B<sigpending>() returns the set of signals that are pending for delivery to "
6549 "the calling thread (i.e., the signals which have been raised while "
6550 "blocked). The mask of pending signals is returned in I<set>."
6554 #: build/C/man2/sigpending.2:54
6555 msgid "B<sigpending>() returns 0 on success and -1 on error."
6559 #: build/C/man2/sigpending.2:59
6561 "I<set> points to memory which is not a valid part of the process address "
6566 #: build/C/man2/sigpending.2:70
6568 "The set of signals that is pending for a thread is the union of the set of "
6569 "signals that is pending for that thread and the set of signals that is "
6570 "pending for the process as a whole; see B<signal>(7)."
6574 #: build/C/man2/sigpending.2:82
6576 "In versions of glibc up to and including 2.2.1, there is a bug in the "
6577 "wrapper function for B<sigpending>() which means that information about "
6578 "pending real-time signals is not correctly returned."
6582 #: build/C/man2/sigpending.2:89
6584 "B<kill>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
6585 "B<sigsuspend>(2), B<sigsetops>(3), B<signal>(7)"
6589 #: build/C/man2/sigprocmask.2:27
6595 #: build/C/man2/sigprocmask.2:27
6601 #: build/C/man2/sigprocmask.2:30
6602 msgid "sigprocmask - examine and change blocked signals"
6606 #: build/C/man2/sigprocmask.2:35
6608 "B<int sigprocmask(int >I<how>B<, const sigset_t *>I<set>B<,> B<sigset_t "
6613 #: build/C/man2/sigprocmask.2:44
6615 "B<sigprocmask>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
6620 #: build/C/man2/sigprocmask.2:53
6622 "B<sigprocmask>() is used to fetch and/or change the signal mask of the "
6623 "calling thread. The signal mask is the set of signals whose delivery is "
6624 "currently blocked for the caller (see also B<signal>(7) for more details)."
6628 #: build/C/man2/sigprocmask.2:57
6629 msgid "The behavior of the call is dependent on the value of I<how>, as follows."
6633 #: build/C/man2/sigprocmask.2:57
6635 msgid "B<SIG_BLOCK>"
6639 #: build/C/man2/sigprocmask.2:62
6641 "The set of blocked signals is the union of the current set and the I<set> "
6646 #: build/C/man2/sigprocmask.2:62
6648 msgid "B<SIG_UNBLOCK>"
6652 #: build/C/man2/sigprocmask.2:68
6654 "The signals in I<set> are removed from the current set of blocked signals. "
6655 "It is permissible to attempt to unblock a signal which is not blocked."
6659 #: build/C/man2/sigprocmask.2:68
6661 msgid "B<SIG_SETMASK>"
6665 #: build/C/man2/sigprocmask.2:72
6666 msgid "The set of blocked signals is set to the argument I<set>."
6670 #: build/C/man2/sigprocmask.2:77
6672 "If I<oldset> is non-NULL, the previous value of the signal mask is stored in "
6677 #: build/C/man2/sigprocmask.2:86
6679 "If I<set> is NULL, then the signal mask is unchanged (i.e., I<how> is "
6680 "ignored), but the current value of the signal mask is nevertheless returned "
6681 "in I<oldset> (if it is not NULL)."
6685 #: build/C/man2/sigprocmask.2:91
6687 "The use of B<sigprocmask>() is unspecified in a multithreaded process; see "
6688 "B<pthread_sigmask>(3)."
6692 #: build/C/man2/sigprocmask.2:94
6693 msgid "B<sigprocmask>() returns 0 on success and -1 on error."
6697 #: build/C/man2/sigprocmask.2:102
6699 "the I<set> or I<oldset> argument points outside the process's allocated "
6704 #: build/C/man2/sigprocmask.2:107
6705 msgid "The value specified in I<how> was invalid."
6709 #: build/C/man2/sigprocmask.2:113
6711 "It is not possible to block B<SIGKILL> or B<SIGSTOP>. Attempts to do so are "
6716 #: build/C/man2/sigprocmask.2:115
6717 msgid "Each of the threads in a process has its own signal mask."
6721 #: build/C/man2/sigprocmask.2:135
6723 "If B<SIGBUS>, B<SIGFPE>, B<SIGILL>, or B<SIGSEGV> are generated while they "
6724 "are blocked, the result is undefined, unless the signal was generated by "
6725 "B<kill>(2), B<sigqueue>(3), or B<raise>(3)."
6729 #: build/C/man2/sigprocmask.2:149
6731 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigpending>(2), "
6732 "B<sigsuspend>(2), B<pthread_sigmask>(3), B<sigqueue>(3), B<sigsetops>(3), "
6737 #: build/C/man3/sigqueue.3:26
6743 #: build/C/man3/sigqueue.3:26
6749 #: build/C/man3/sigqueue.3:29
6750 msgid "sigqueue - queue a signal and data to a process"
6754 #: build/C/man3/sigqueue.3:33
6756 "B<int sigqueue(pid_t >I<pid>B<, int >I<sig>B<, const union sigval "
6761 #: build/C/man3/sigqueue.3:41
6762 msgid "B<sigqueue>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
6766 #: build/C/man3/sigqueue.3:53
6768 "B<sigqueue>() sends the signal specified in I<sig> to the process whose PID "
6769 "is given in I<pid>. The permissions required to send a signal are the same "
6770 "as for B<kill>(2). As with B<kill>(2), the null signal (0) can be used to "
6771 "check if a process with a given PID exists."
6775 #: build/C/man3/sigqueue.3:58
6777 "The I<value> argument is used to specify an accompanying item of data "
6778 "(either an integer or a pointer value) to be sent with the signal, and has "
6779 "the following type:"
6783 #: build/C/man3/sigqueue.3:65
6788 " void *sival_ptr;\n"
6793 #: build/C/man3/sigqueue.3:81
6795 "If the receiving process has installed a handler for this signal using the "
6796 "B<SA_SIGINFO> flag to B<sigaction>(2), then it can obtain this data via the "
6797 "I<si_value> field of the I<siginfo_t> structure passed as the second "
6798 "argument to the handler. Furthermore, the I<si_code> field of that "
6799 "structure will be set to B<SI_QUEUE>."
6803 #: build/C/man3/sigqueue.3:89
6805 "On success, B<sigqueue>() returns 0, indicating that the signal was "
6806 "successfully queued to the receiving process. Otherwise -1 is returned and "
6807 "I<errno> is set to indicate the error."
6811 #: build/C/man3/sigqueue.3:100
6812 msgid "I<sig> was invalid."
6816 #: build/C/man3/sigqueue.3:106
6818 "The process does not have permission to send the signal to the receiving "
6819 "process. For the required permissions, see B<kill>(2)."
6823 #: build/C/man3/sigqueue.3:110
6824 msgid "No process has a PID matching I<pid>."
6828 #: build/C/man3/sigqueue.3:112
6829 msgid "This system call first appeared in Linux 2.2."
6833 #: build/C/man3/sigqueue.3:122
6835 "If this function results in the sending of a signal to the process that "
6836 "invoked it, and that signal was not blocked by the calling thread, and no "
6837 "other threads were willing to handle this signal (either by having it "
6838 "unblocked, or by waiting for it using B<sigwait>(3)), then at least some "
6839 "signal must be delivered to this thread before this function returns."
6843 #: build/C/man3/sigqueue.3:137
6845 "On Linux, this function is implemented using the B<rt_sigqueueinfo>(2) "
6846 "system call. The system call differs in its third argument, which is the "
6847 "I<siginfo_t> structure that will be supplied to the receiving process's "
6848 "signal handler or returned by the receiving process's B<sigtimedwait>(2) "
6849 "call. Inside the glibc B<sigqueue>() wrapper, this argument, I<uinfo>, is "
6850 "initialized as follows:"
6854 #: build/C/man3/sigqueue.3:145
6857 "uinfo.si_signo = sig; /* argument supplied to sigqueue() */\n"
6858 "uinfo.si_code = SI_QUEUE;\n"
6859 "uinfo.si_pid = getpid(); /* Process ID of sender */\n"
6860 "uinfo.si_uid = getuid(); /* Real UID of sender */\n"
6861 "uinfo.si_value = val; /* argument supplied to sigqueue() */\n"
6865 #: build/C/man3/sigqueue.3:154
6867 "B<kill>(2), B<rt_sigqueueinfo>(2), B<sigaction>(2), B<signal>(2), "
6868 "B<pthread_sigqueue>(3), B<sigwait>(3), B<signal>(7)"
6872 #: build/C/man2/sigreturn.2:27
6878 #: build/C/man2/sigreturn.2:27
6884 #: build/C/man2/sigreturn.2:30
6885 msgid "sigreturn - return from signal handler and cleanup stack frame"
6889 #: build/C/man2/sigreturn.2:32
6890 msgid "B<int sigreturn(unsigned long >I<__unused>B<);>"
6894 #: build/C/man2/sigreturn.2:40
6896 "When the Linux kernel creates the stack frame for a signal handler, a call "
6897 "to B<sigreturn>() is inserted into the stack frame so that upon return from "
6898 "the signal handler, B<sigreturn>() will be called."
6902 #: build/C/man2/sigreturn.2:51
6904 "This B<sigreturn>() call undoes everything that was done\\(emchanging the "
6905 "process's signal mask, switching stacks (see B<sigaltstack>(2))\\(emin order "
6906 "to invoke the signal handler: it restores the process's signal mask, "
6907 "switches stacks, and restores the process's context (registers, processor "
6908 "flags), so that the process directly resumes execution at the point where it "
6909 "was interrupted by the signal."
6913 #: build/C/man2/sigreturn.2:54
6914 msgid "B<sigreturn>() never returns."
6918 #: build/C/man2/sigreturn.2:54
6924 #: build/C/man2/sigreturn.2:56
6925 msgid "/usr/src/linux/arch/i386/kernel/signal.c"
6929 #: build/C/man2/sigreturn.2:58
6930 msgid "/usr/src/linux/arch/alpha/kernel/entry.S"
6934 #: build/C/man2/sigreturn.2:62
6936 "B<sigreturn>() is specific to Linux and should not be used in programs "
6937 "intended to be portable."
6941 #: build/C/man2/sigreturn.2:72
6943 "The B<sigreturn>() call is used by the kernel to implement signal "
6944 "handlers. It should B<never> be called directly. Better yet, the specific "
6945 "use of the I<__unused> argument varies depending on the architecture."
6949 #: build/C/man2/sigreturn.2:76
6950 msgid "B<kill>(2), B<sigaltstack>(2), B<signal>(2), B<signal>(7)"
6954 #: build/C/man3/sigset.3:24
6960 #: build/C/man3/sigset.3:27
6961 msgid "sigset, sighold, sigrelse, sigignore - System V signal API"
6965 #: build/C/man3/sigset.3:33
6966 msgid "B<sighandler_t sigset(int >I<sig>B<, sighandler_t >I<disp>B<);>"
6970 #: build/C/man3/sigset.3:35
6971 msgid "B<int sighold(int >I<sig>B<);>"
6975 #: build/C/man3/sigset.3:37
6976 msgid "B<int sigrelse(int >I<sig>B<);>"
6980 #: build/C/man3/sigset.3:39
6981 msgid "B<int sigignore(int >I<sig>B<);>"
6985 #: build/C/man3/sigset.3:50
6986 msgid "B<sigset>(), B<sighold>(), B<sigrelse>(), B<sigignore>():"
6990 #: build/C/man3/sigset.3:54
6991 msgid "_XOPEN_SOURCE\\ E<gt>=\\ 500 || _XOPEN_SOURCE\\ &&\\ _XOPEN_SOURCE_EXTENDED"
6995 #: build/C/man3/sigset.3:63
6997 "These functions are provided in glibc as a compatibility interface for "
6998 "programs that make use of the historical System V signal API. This API is "
6999 "obsolete: new applications should use the POSIX signal API (B<sigaction>(2), "
7000 "B<sigprocmask>(2), etc.)"
7004 #: build/C/man3/sigset.3:72
7006 "The B<sigset>() function modifies the disposition of the signal I<sig>. "
7007 "The I<disp> argument can be the address of a signal handler function, or one "
7008 "of the following constants:"
7012 #: build/C/man3/sigset.3:72
7018 #: build/C/man3/sigset.3:77
7019 msgid "Reset the disposition of I<sig> to the default."
7023 #: build/C/man3/sigset.3:77
7029 #: build/C/man3/sigset.3:81
7030 msgid "Ignore I<sig>."
7034 #: build/C/man3/sigset.3:81
7040 #: build/C/man3/sigset.3:88
7042 "Add I<sig> to the process's signal mask, but leave the disposition of I<sig> "
7047 #: build/C/man3/sigset.3:94
7049 "If I<disp> specifies the address of a signal handler, then I<sig> is added "
7050 "to the process's signal mask during execution of the handler."
7054 #: build/C/man3/sigset.3:102
7056 "If I<disp> was specified as a value other than B<SIG_HOLD>, then I<sig> is "
7057 "removed from the process's signal mask."
7061 #: build/C/man3/sigset.3:108 build/C/man3/sigvec.3:85
7062 msgid "The dispositions for B<SIGKILL> and B<SIGSTOP> cannot be changed."
7066 #: build/C/man3/sigset.3:114
7067 msgid "The B<sighold>() function adds I<sig> to the calling process's signal mask."
7071 #: build/C/man3/sigset.3:120
7073 "The B<sigrelse>() function removes I<sig> from the calling process's signal "
7078 #: build/C/man3/sigset.3:127
7079 msgid "The B<sigignore>() function sets the disposition of I<sig> to B<SIG_IGN>."
7083 #: build/C/man3/sigset.3:143
7085 "On success, B<sigset>() returns B<SIG_HOLD> if I<sig> was blocked before "
7086 "the call, or the signal's previous disposition if it was not blocked before "
7087 "the call. On error, B<sigset>() returns -1, with I<errno> set to indicate "
7088 "the error. (But see BUGS below.)"
7092 #: build/C/man3/sigset.3:152
7094 "The B<sighold>(), B<sigrelse>(), and B<sigignore>() functions return 0 on "
7095 "success; on error, these functions return -1 and set I<errno> to indicate "
7100 #: build/C/man3/sigset.3:159
7102 "For B<sigset>() see the ERRORS under B<sigaction>(2) and "
7103 "B<sigprocmask>(2)."
7107 #: build/C/man3/sigset.3:166
7108 msgid "For B<sighold>() and B<sigrelse>() see the ERRORS under B<sigprocmask>(2)."
7112 #: build/C/man3/sigset.3:171
7113 msgid "For B<sigignore>(), see the errors under B<sigaction>(2)."
7117 #: build/C/man3/sigset.3:188
7119 "SVr4, POSIX.1-2001. These functions are obsolete: do not use them in new "
7120 "programs. POSIX.1-2008 marks B<sighold>(), B<sigignore>(), B<sigpause>(), "
7121 "B<sigrelse>(), and B<sigset>() as obsolete, recommending the use of "
7122 "B<sigaction>(2), B<sigprocmask>(2), B<pthread_sigmask>(3), and "
7123 "B<sigsuspend>(2) instead."
7127 #: build/C/man3/sigset.3:190
7128 msgid "These functions appeared in glibc version 2.1."
7132 #: build/C/man3/sigset.3:196
7134 "The I<sighandler_t> type is a GNU extension; it is only used on this page to "
7135 "make the B<sigset>() prototype more easily readable."
7139 #: build/C/man3/sigset.3:204
7141 "The B<sigset>() function provides reliable signal handling semantics (as "
7142 "when calling B<sigaction>(2) with I<sa_mask> equal to 0)."
7146 #: build/C/man3/sigset.3:222
7148 "On System V, the B<signal>() function provides unreliable semantics (as "
7149 "when calling B<sigaction>(2) with I<sa_mask> equal to I<SA_RESETHAND | "
7150 "SA_NODEFER>). On BSD, B<signal>() provides reliable semantics. "
7151 "POSIX.1-2001 leaves these aspects of B<signal>() unspecified. See "
7152 "B<signal>(2) for further details."
7156 #: build/C/man3/sigset.3:230 build/C/man3/sigvec.3:250
7158 "In order to wait for a signal, BSD and System V both provided a function "
7159 "named B<sigpause>(3), but this function has a different argument on the two "
7160 "systems. See B<sigpause>(3) for details."
7164 #: build/C/man3/sigset.3:239
7166 "In versions of glibc before 2.2, B<sigset>() did not unblock I<sig> if "
7167 "I<disp> was specified as a value other than B<SIG_HOLD>."
7170 #. See http://sourceware.org/bugzilla/show_bug.cgi?id=1951
7172 #: build/C/man3/sigset.3:264
7174 "In versions of glibc before 2.5, B<sigset>() does not correctly return the "
7175 "previous disposition of the signal in two cases. First, if I<disp> is "
7176 "specified as B<SIG_HOLD>, then a successful B<sigset>() always returns "
7177 "B<SIG_HOLD>. Instead, it should return the previous disposition of the "
7178 "signal (unless the signal was blocked, in which case B<SIG_HOLD> should be "
7179 "returned). Second, if the signal is currently blocked, then the return "
7180 "value of a successful B<sigset>() should be B<SIG_HOLD>. Instead, the "
7181 "previous disposition of the signal is returned. These problems have been "
7182 "fixed since glibc 2.5."
7186 #: build/C/man3/sigset.3:273
7188 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
7189 "B<raise>(3), B<sigpause>(3), B<sigvec>(3), B<signal>(7)"
7193 #: build/C/man3/sigsetops.3:29
7199 #: build/C/man3/sigsetops.3:29
7205 #: build/C/man3/sigsetops.3:33
7207 "sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX signal "
7212 #: build/C/man3/sigsetops.3:37
7213 msgid "B<int sigemptyset(sigset_t *>I<set>B<);>"
7217 #: build/C/man3/sigsetops.3:39
7218 msgid "B<int sigfillset(sigset_t *>I<set>B<);>"
7222 #: build/C/man3/sigsetops.3:41
7223 msgid "B<int sigaddset(sigset_t *>I<set>B<, int >I<signum>B<);>"
7227 #: build/C/man3/sigsetops.3:43
7228 msgid "B<int sigdelset(sigset_t *>I<set>B<, int >I<signum>B<);>"
7232 #: build/C/man3/sigsetops.3:45
7233 msgid "B<int sigismember(const sigset_t *>I<set>B<, int >I<signum>B<);>"
7237 #: build/C/man3/sigsetops.3:57
7239 "B<sigemptyset>(), B<sigfillset>(), B<sigaddset>(), B<sigdelset>(), "
7244 #: build/C/man3/sigsetops.3:59
7245 msgid "_POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE"
7249 #: build/C/man3/sigsetops.3:63
7250 msgid "These functions allow the manipulation of POSIX signal sets."
7254 #: build/C/man3/sigsetops.3:68
7256 "B<sigemptyset>() initializes the signal set given by I<set> to empty, with "
7257 "all signals excluded from the set."
7261 #: build/C/man3/sigsetops.3:73
7262 msgid "B<sigfillset>() initializes I<set> to full, including all signals."
7266 #: build/C/man3/sigsetops.3:81
7268 "B<sigaddset>() and B<sigdelset>() add and delete respectively signal "
7269 "I<signum> from I<set>."
7273 #: build/C/man3/sigsetops.3:87
7274 msgid "B<sigismember>() tests whether I<signum> is a member of I<set>."
7278 #: build/C/man3/sigsetops.3:105
7280 "Objects of type I<sigset_t> must be initialized by a call to either "
7281 "B<sigemptyset>() or B<sigfillset>() before being passed to the functions "
7282 "B<sigaddset>(), B<sigdelset>() and B<sigismember>() or the additional "
7283 "glibc functions described below (B<sigisemptyset>(), B<sigandset>(), and "
7284 "B<sigorset>()). The results are undefined if this is not done."
7288 #: build/C/man3/sigsetops.3:112
7290 "B<sigemptyset>(), B<sigfillset>(), B<sigaddset>(), and B<sigdelset>() "
7291 "return 0 on success and -1 on error."
7295 #: build/C/man3/sigsetops.3:121
7297 "B<sigismember>() returns 1 if I<signum> is a member of I<set>, 0 if "
7298 "I<signum> is not a member, and -1 on error."
7302 #: build/C/man3/sigsetops.3:126
7303 msgid "I<sig> is not a valid signal."
7307 #: build/C/man3/sigsetops.3:129
7313 #: build/C/man3/sigsetops.3:135
7315 "If the B<_GNU_SOURCE> feature test macro is defined, then "
7316 "I<E<lt>signal.hE<gt>> exposes three other functions for manipulating signal "
7321 #: build/C/man3/sigsetops.3:135
7323 msgid "B<int sigisemptyset(sigset_t *>I<set>B<);>"
7327 #: build/C/man3/sigsetops.3:140
7328 msgid "returns 1 if I<set> contains no signals, and 0 otherwise."
7332 #: build/C/man3/sigsetops.3:140
7335 "B<int sigorset(sigset_t *>I<dest>B<, sigset_t *>I<left>B<, sigset_t "
7340 #: build/C/man3/sigsetops.3:149
7341 msgid "places the union of the sets I<left> and I<right> in I<dest>."
7345 #: build/C/man3/sigsetops.3:149
7348 "B<int sigandset(sigset_t *>I<dest>B<, sigset_t *>I<left>B<, sigset_t "
7353 #: build/C/man3/sigsetops.3:158
7354 msgid "places the intersection of the sets I<left> and I<right> in I<dest>."
7358 #: build/C/man3/sigsetops.3:163
7359 msgid "B<sigorset>() and B<sigandset>() return 0 on success, and -1 on failure."
7363 #: build/C/man3/sigsetops.3:166
7365 "These functions are nonstandard (a few other systems provide similar "
7366 "functions) and their use should be avoided in portable applications."
7370 #: build/C/man3/sigsetops.3:170
7371 msgid "B<sigaction>(2), B<sigpending>(2), B<sigprocmask>(2), B<sigsuspend>(2)"
7375 #: build/C/man2/sigsuspend.2:27
7381 #: build/C/man2/sigsuspend.2:27
7387 #: build/C/man2/sigsuspend.2:30
7388 msgid "sigsuspend - wait for a signal"
7392 #: build/C/man2/sigsuspend.2:34
7393 msgid "B<int sigsuspend(const sigset_t *>I<mask>B<);>"
7397 #: build/C/man2/sigsuspend.2:43
7399 "B<sigsuspend>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
7404 #: build/C/man2/sigsuspend.2:51
7406 "B<sigsuspend>() temporarily replaces the signal mask of the calling process "
7407 "with the mask given by I<mask> and then suspends the process until delivery "
7408 "of a signal whose action is to invoke a signal handler or to terminate a "
7413 #: build/C/man2/sigsuspend.2:60
7415 "If the signal terminates the process, then B<sigsuspend>() does not "
7416 "return. If the signal is caught, then B<sigsuspend>() returns after the "
7417 "signal handler returns, and the signal mask is restored to the state before "
7418 "the call to B<sigsuspend>()."
7422 #: build/C/man2/sigsuspend.2:68
7424 "It is not possible to block B<SIGKILL> or B<SIGSTOP>; specifying these "
7425 "signals in I<mask>, has no effect on the process's signal mask."
7429 #: build/C/man2/sigsuspend.2:72
7430 msgid "B<sigsuspend>() always returns -1, normally with the error B<EINTR>."
7434 #: build/C/man2/sigsuspend.2:77
7436 "I<mask> points to memory which is not a valid part of the process address "
7441 #: build/C/man2/sigsuspend.2:80
7442 msgid "The call was interrupted by a signal."
7446 #: build/C/man2/sigsuspend.2:100
7448 "Normally, B<sigsuspend>() is used in conjunction with B<sigprocmask>(2) in "
7449 "order to prevent delivery of a signal during the execution of a critical "
7450 "code section. The caller first blocks the signals with B<sigprocmask>(2). "
7451 "When the critical code has completed, the caller then waits for the signals "
7452 "by calling B<sigsuspend>() with the signal mask that was returned by "
7453 "B<sigprocmask>(2) (in the I<oldset> argument)."
7457 #: build/C/man2/sigsuspend.2:113
7459 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
7460 "B<sigwaitinfo>(2), B<sigsetops>(3), B<sigwait>(3), B<signal>(7)"
7464 #: build/C/man3/sigvec.3:24
7470 #: build/C/man3/sigvec.3:27
7471 msgid "sigvec, sigblock, sigsetmask, siggetmask, sigmask - BSD signal API"
7475 #: build/C/man3/sigvec.3:31
7477 "B<int sigvec(int >I<sig>B<, struct sigvec *>I<vec>B<, struct sigvec "
7482 #: build/C/man3/sigvec.3:33
7483 msgid "B<int sigmask(int >I<signum>B<);>"
7487 #: build/C/man3/sigvec.3:35
7488 msgid "B<int sigblock(int >I<mask>B<);>"
7492 #: build/C/man3/sigvec.3:37
7493 msgid "B<int sigsetmask(int >I<mask>B<);>"
7497 #: build/C/man3/sigvec.3:39
7498 msgid "B<int siggetmask(void);>"
7502 #: build/C/man3/sigvec.3:47
7503 msgid "All functions shown above: _BSD_SOURCE"
7507 #: build/C/man3/sigvec.3:54
7509 "These functions are provided in glibc as a compatibility interface for "
7510 "programs that make use of the historical BSD signal API. This API is "
7511 "obsolete: new applications should use the POSIX signal API (B<sigaction>(2), "
7512 "B<sigprocmask>(2), etc.)"
7516 #: build/C/man3/sigvec.3:79
7518 "The B<sigvec>() function sets and/or gets the disposition of the signal "
7519 "I<sig> (like the POSIX B<sigaction>(2)). If I<vec> is not NULL, it points "
7520 "to a I<sigvec> structure that defines the new disposition for I<sig>. If "
7521 "I<ovec> is not NULL, it points to a I<sigvec> structure that is used to "
7522 "return the previous disposition of I<sig>. To obtain the current "
7523 "disposition of I<sig> without changing it, specify NULL for I<vec>, and a "
7524 "non-NULL pointer for I<ovec>."
7528 #: build/C/man3/sigvec.3:89
7529 msgid "The I<sigvec> structure has the following form:"
7533 #: build/C/man3/sigvec.3:97
7537 " void (*sv_handler)(); /* Signal disposition */\n"
7538 " int sv_mask; /* Signals to be blocked in handler */\n"
7539 " int sv_flags; /* Flags */\n"
7544 #: build/C/man3/sigvec.3:108
7546 "The I<sv_handler> field specifies the disposition of the signal, and is "
7547 "either: the address of a signal handler function; or B<SIG_DFL> meaning the "
7548 "default disposition applies for the signal; or B<SIG_IGN> meaning that the "
7549 "signal is ignored."
7553 #: build/C/man3/sigvec.3:122
7555 "If I<sv_handler> specifies the address of a signal handler, then I<sv_mask> "
7556 "specifies a mask of signals that are to be blocked while the handler is "
7557 "executing. In addition, the signal for which the handler is invoked is also "
7558 "blocked by default. Attempts to block B<SIGKILL> or B<SIGSTOP> are silently "
7563 #: build/C/man3/sigvec.3:129
7565 "If I<sv_handler> specifies the address of a signal handler, then the "
7566 "I<sv_flags> field specifies flags controlling what happens when the handler "
7567 "is called. This field may contain zero or more of the following flags:"
7571 #: build/C/man3/sigvec.3:129
7573 msgid "B<SV_INTERRUPT>"
7577 #: build/C/man3/sigvec.3:137
7579 "If the signal handler interrupts a blocking system call, then upon return "
7580 "from the handler the system call will not be restarted: instead it will fail "
7581 "with the error B<EINTR>. If this flag is not specified, then system calls "
7582 "are restarted by default."
7586 #: build/C/man3/sigvec.3:137
7588 msgid "B<SV_RESETHAND>"
7592 #: build/C/man3/sigvec.3:146
7594 "Reset the disposition of the signal to the default before calling the signal "
7595 "handler. If this flag is not specified, then the handler remains "
7596 "established until explicitly removed by a later call to B<sigvec>() or "
7597 "until the process performs an B<execve>(2)."
7601 #: build/C/man3/sigvec.3:146
7603 msgid "B<SV_ONSTACK>"
7607 #: build/C/man3/sigvec.3:153
7609 "Handle the signal on the alternate signal stack (historically established "
7610 "under BSD using the obsolete B<sigstack>() function; the POSIX replacement "
7611 "is B<sigaltstack>(2))."
7615 #: build/C/man3/sigvec.3:163
7617 "The B<sigmask>() function constructs and returns a \"signal mask\" for "
7618 "I<signum>. For example, we can initialize the I<vec.sv_mask> field given to "
7619 "B<sigvec>() using code such as the following:"
7623 #: build/C/man3/sigvec.3:168
7626 " vec.sv_mask = sigmask(SIGQUIT) | sigpause(SIGABRT);\n"
7627 " /* Block SIGQUIT and SIGABRT during\n"
7628 " handler execution */\n"
7632 #: build/C/man3/sigvec.3:183
7634 "The B<sigblock>() function adds the signals in I<mask> to the process's "
7635 "signal mask (like POSIX I<sigprocmask(SIG_BLOCK)>), and returns the "
7636 "process's previous signal mask. Attempts to block B<SIGKILL> or B<SIGSTOP> "
7637 "are silently ignored."
7641 #: build/C/man3/sigvec.3:191
7643 "The B<sigsetmask>() function sets the process's signal mask to the value "
7644 "given in I<mask> (like POSIX I<sigprocmask(SIG_SETMASK)>), and returns the "
7645 "process's previous signal mask."
7649 #: build/C/man3/sigvec.3:197
7651 "The B<siggetmask>() function returns the process's current signal mask. "
7652 "This call is equivalent to I<sigblock(0)>."
7656 #: build/C/man3/sigvec.3:203
7658 "The B<sigvec>() function returns 0 on success; on error, it returns -1 and "
7659 "sets I<errno> to indicate the error."
7663 #: build/C/man3/sigvec.3:209
7665 "The B<sigblock>() and B<sigsetmask>() functions return the previous signal "
7670 #: build/C/man3/sigvec.3:214
7671 msgid "The B<sigmask>() function returns the signal mask for I<signum>."
7675 #: build/C/man3/sigvec.3:219
7676 msgid "See the ERRORS under B<sigaction>(2) and B<sigprocmask>(2)."
7680 #: build/C/man3/sigvec.3:225
7682 "All of these functions were in 4.3BSD, except B<siggetmask>(), whose origin "
7683 "is unclear. These functions are obsolete: do not use them in new programs."
7687 #: build/C/man3/sigvec.3:242
7689 "On 4.3BSD, the B<signal>() function provided reliable semantics (as when "
7690 "calling B<sigvec>() with I<vec.sv_mask> equal to 0). On System V, "
7691 "B<signal>() provides unreliable semantics. POSIX.1-2001 leaves these "
7692 "aspects of B<signal>() unspecified. See B<signal>(2) for further details."
7696 #: build/C/man3/sigvec.3:259
7698 "B<kill>(2), B<pause>(2), B<sigaction>(2), B<signal>(2), B<sigprocmask>(2), "
7699 "B<raise>(3), B<sigpause>(3), B<sigset>(3), B<signal>(7)"
7703 #: build/C/man3/sigwait.3:24
7709 #: build/C/man3/sigwait.3:24
7715 #: build/C/man3/sigwait.3:27
7716 msgid "sigwait - wait for a signal"
7720 #: build/C/man3/sigwait.3:32
7722 msgid "B< int sigwait(const sigset_t *>I<set>B<, int *>I<sig>B<);>\n"
7726 #: build/C/man3/sigwait.3:42
7727 msgid "B<sigwait>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE"
7731 #: build/C/man3/sigwait.3:53
7733 "The B<sigwait>() function suspends execution of the calling thread until "
7734 "the delivery of one of the signals specified in the signal set I<set>. The "
7735 "function accepts the signal (removes it from the pending list of signals), "
7736 "and returns the signal number in I<sig>."
7740 #: build/C/man3/sigwait.3:59
7742 "The operation of B<sigwait>() is the same as B<sigwaitinfo>(2), except "
7747 #: build/C/man3/sigwait.3:64
7749 "B<sigwait>() only returns the signal number, rather than a I<siginfo_t> "
7750 "structure describing the signal."
7754 #: build/C/man3/sigwait.3:66
7755 msgid "The return values of the two functions are different."
7759 #: build/C/man3/sigwait.3:71
7761 "On success, B<sigwait>() returns 0. On error, it returns a positive error "
7762 "number (listed in ERRORS)."
7765 #. Does not occur for glibc.
7767 #: build/C/man3/sigwait.3:77
7768 msgid "I<set> contains an invalid signal number."
7772 #: build/C/man3/sigwait.3:83
7773 msgid "B<sigwait>() is implemented using B<sigtimedwait>(2)."
7777 #: build/C/man3/sigwait.3:86
7778 msgid "See B<pthread_sigmask>(3)."
7782 #: build/C/man3/sigwait.3:93
7784 "B<sigaction>(2), B<signalfd>(2), B<sigpending>(2), B<sigsuspend>(2), "
7785 "B<sigwaitinfo>(2), B<sigsetops>(3), B<signal>(7)"
7789 #: build/C/man2/sigwaitinfo.2:23
7795 #: build/C/man2/sigwaitinfo.2:23
7801 #: build/C/man2/sigwaitinfo.2:26
7802 msgid "sigwaitinfo, sigtimedwait - synchronously wait for queued signals"
7806 #: build/C/man2/sigwaitinfo.2:31
7808 msgid "B<int sigwaitinfo(const sigset_t *>I<set>B<, siginfo_t *>I<info>B<);>\n"
7812 #: build/C/man2/sigwaitinfo.2:34
7815 "B<int sigtimedwait(const sigset_t *>I<set>B<, siginfo_t *>I<info>B<, >\n"
7816 "B< const struct timespec *>I<timeout>B<);>\n"
7820 #: build/C/man2/sigwaitinfo.2:44
7821 msgid "B<sigwaitinfo>(), B<sigtimedwait>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
7825 #: build/C/man2/sigwaitinfo.2:54
7827 "B<sigwaitinfo>() suspends execution of the calling thread until one of the "
7828 "signals in I<set> is delivered. (If one of the signals in I<set> is already "
7829 "pending for the calling thread, B<sigwaitinfo>() will return immediately "
7830 "with information about that signal.)"
7834 #: build/C/man2/sigwaitinfo.2:66
7836 "B<sigwaitinfo>() removes the delivered signal from the set of pending "
7837 "signals and returns the signal number as its function result. If the "
7838 "I<info> argument is not NULL, then it returns a structure of type "
7839 "I<siginfo_t> (see B<sigaction>(2)) containing information about the signal."
7843 #: build/C/man2/sigwaitinfo.2:72
7845 "Signals returned via B<sigwaitinfo>() are delivered in the usual order; see "
7846 "B<signal>(7) for further details."
7850 #: build/C/man2/sigwaitinfo.2:81
7852 "B<sigtimedwait>() operates in exactly the same way as B<sigwaitinfo>() "
7853 "except that it has an additional argument, I<timeout>, which enables an "
7854 "upper bound to be placed on the time for which the thread is suspended. "
7855 "This argument is of the following type:"
7859 #: build/C/man2/sigwaitinfo.2:88
7862 "struct timespec {\n"
7863 " long tv_sec; /* seconds */\n"
7864 " long tv_nsec; /* nanoseconds */\n"
7869 #: build/C/man2/sigwaitinfo.2:98
7871 "If both fields of this structure are specified as 0, a poll is performed: "
7872 "B<sigtimedwait>() returns immediately, either with information about a "
7873 "signal that was pending for the caller, or with an error if none of the "
7874 "signals in I<set> was pending."
7878 #: build/C/man2/sigwaitinfo.2:107
7880 "On success, both B<sigwaitinfo>() and B<sigtimedwait>() return a signal "
7881 "number (i.e., a value greater than zero). On failure both calls return -1, "
7882 "with I<errno> set to indicate the error."
7886 #: build/C/man2/sigwaitinfo.2:116
7888 "No signal in I<set> was delivered within the I<timeout> period specified to "
7889 "B<sigtimedwait>()."
7893 #: build/C/man2/sigwaitinfo.2:122
7895 "The wait was interrupted by a signal handler; see B<signal>(7). (This "
7896 "handler was for a signal other than one of those in I<set>.)"
7900 #: build/C/man2/sigwaitinfo.2:126
7901 msgid "I<timeout> was invalid."
7905 #: build/C/man2/sigwaitinfo.2:145
7907 "In normal usage, the calling program blocks the signals in I<set> via a "
7908 "prior call to B<sigprocmask>(2) (so that the default disposition for these "
7909 "signals does not occur if they are delivered between successive calls to "
7910 "B<sigwaitinfo>() or B<sigtimedwait>()) and does not establish handlers for "
7911 "these signals. In a multithreaded program, the signal should be blocked in "
7912 "all threads to prevent the signal being delivered to a thread other than the "
7913 "one calling B<sigwaitinfo>() or B<sigtimedwait>())."
7917 #: build/C/man2/sigwaitinfo.2:150
7919 "The set of signals that is pending for a given thread is the union of the "
7920 "set of signals that is pending specifically for that thread and the set of "
7921 "signals that is pending for the process as a whole (see B<signal>(7))."
7925 #: build/C/man2/sigwaitinfo.2:156
7926 msgid "Attempts to wait for B<SIGKILL> and B<SIGSTOP> are silently ignored."
7930 #: build/C/man2/sigwaitinfo.2:165
7932 "If multiple threads of a process are blocked waiting for the same signal(s) "
7933 "in B<sigwaitinfo>() or B<sigtimedwait>(), then exactly one of the threads "
7934 "will actually receive the signal if it is delivered to the process as a "
7935 "whole; which of the threads receives the signal is indeterminate."
7939 #: build/C/man2/sigwaitinfo.2:174
7941 "POSIX leaves the meaning of a NULL value for the I<timeout> argument of "
7942 "B<sigtimedwait>() unspecified, permitting the possibility that this has the "
7943 "same meaning as a call to B<sigwaitinfo>(), and indeed this is what is done "
7948 #: build/C/man2/sigwaitinfo.2:179
7950 "On Linux, B<sigwaitinfo>() is a library function implemented on top of "
7951 "B<sigtimedwait>()."
7955 #: build/C/man2/sigwaitinfo.2:190
7957 "B<kill>(2), B<sigaction>(2), B<signal>(2), B<signalfd>(2), B<sigpending>(2), "
7958 "B<sigprocmask>(2), B<sigqueue>(3), B<sigsetops>(3), B<sigwait>(3), "
7959 "B<signal>(7), B<time>(7)"
7963 #: build/C/man3/sysv_signal.3:23
7969 #: build/C/man3/sysv_signal.3:23
7975 #: build/C/man3/sysv_signal.3:26
7976 msgid "sysv_signal - signal handling with System V semantics"
7980 #: build/C/man3/sysv_signal.3:28
7981 msgid "B<#define _GNU_SOURCE> /* See feature_test_macros(7) */"
7985 #: build/C/man3/sysv_signal.3:34
7986 msgid "B<sighandler_t sysv_signal(int >I<signum>B<, sighandler_t >I<handler>B<);>"
7990 #: build/C/man3/sysv_signal.3:39
7992 "The B<sysv_signal>() function takes the same arguments, and performs the "
7993 "same task, as B<signal>(2)."
7997 #: build/C/man3/sysv_signal.3:49
7999 "However B<sysv_signal>() provides the System V unreliable signal semantics, "
8000 "that is: a) the disposition of the signal is reset to the default when the "
8001 "handler is invoked; b) delivery of further instances of the signal is not "
8002 "blocked while the signal handler is executing; and c) if the handler "
8003 "interrupts (certain) blocking system calls, then the system call is not "
8004 "automatically restarted."
8008 #: build/C/man3/sysv_signal.3:55
8010 "The B<sysv_signal>() function returns the previous value of the signal "
8011 "handler, or B<SIG_ERR> on error."
8015 #: build/C/man3/sysv_signal.3:60
8016 msgid "This function is nonstandard."
8020 #: build/C/man3/sysv_signal.3:66
8021 msgid "Use of B<sysv_signal>() should be avoided; use B<sigaction>(2) instead."
8025 #: build/C/man3/sysv_signal.3:77
8027 "On older Linux systems, B<sysv_signal>() and B<signal>(2) were "
8028 "equivalent. But on newer systems, B<signal>(2) provides reliable signal "
8029 "semantics; see B<signal>(2) for details."
8033 #: build/C/man3/sysv_signal.3:89
8034 msgid "B<sigaction>(2), B<signal>(2), B<bsd_signal>(3), B<signal>(7)"
8038 #: build/C/man2/timer_create.2:29
8040 msgid "TIMER_CREATE"
8044 #: build/C/man2/timer_create.2:29
8050 #: build/C/man2/timer_create.2:32
8051 msgid "timer_create - create a POSIX per-process timer"
8055 #: build/C/man2/timer_create.2:36
8058 "B<#include E<lt>signal.hE<gt>>\n"
8059 "B<#include E<lt>time.hE<gt>>\n"
8063 #: build/C/man2/timer_create.2:39
8066 "B<int timer_create(clockid_t >I<clockid>B<, struct sigevent *>I<sevp>B<,>\n"
8067 "B< timer_t *>I<timerid>B<);>\n"
8071 #: build/C/man2/timer_create.2:42 build/C/man2/timer_delete.2:34 build/C/man2/timer_getoverrun.2:34 build/C/man2/timer_settime.2:38
8072 msgid "Link with I<-lrt>."
8076 #: build/C/man2/timer_create.2:50
8077 msgid "B<timer_create>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
8081 #: build/C/man2/timer_create.2:58
8083 "B<timer_create>() creates a new per-process interval timer. The ID of the "
8084 "new timer is returned in the buffer pointed to by I<timerid>, which must be "
8085 "a non-NULL pointer. This ID is unique within the process, until the timer "
8086 "is deleted. The new timer is initially disarmed."
8090 #: build/C/man2/timer_create.2:63
8092 "The I<clockid> argument specifies the clock that the new timer uses to "
8093 "measure time. It can be specified as one of the following values:"
8097 #: build/C/man2/timer_create.2:63
8099 msgid "B<CLOCK_REALTIME>"
8103 #: build/C/man2/timer_create.2:66
8104 msgid "A settable system-wide real-time clock."
8108 #: build/C/man2/timer_create.2:66
8110 msgid "B<CLOCK_MONOTONIC>"
8113 #. Note: the CLOCK_MONOTONIC_RAW clock added for clock_gettime()
8114 #. in 2.6.28 is not supported for POSIX timers -- mtk, Feb 2009
8116 #: build/C/man2/timer_create.2:73
8118 "A nonsettable monotonically increasing clock that measures time from some "
8119 "unspecified point in the past that does not change after system startup."
8123 #: build/C/man2/timer_create.2:73
8125 msgid "B<CLOCK_PROCESS_CPUTIME_ID> (since Linux 2.6.12)"
8129 #: build/C/man2/timer_create.2:77
8131 "A clock that measures (user and system) CPU time consumed by (all of the "
8132 "threads in) the calling process."
8136 #: build/C/man2/timer_create.2:77
8138 msgid "B<CLOCK_THREAD_CPUTIME_ID> (since Linux 2.6.12)"
8141 #. The CLOCK_MONOTONIC_RAW that was added in 2.6.28 can't be used
8142 #. to create a timer -- mtk, Feb 2009
8144 #: build/C/man2/timer_create.2:83
8146 "A clock that measures (user and system) CPU time consumed by the calling "
8151 #: build/C/man2/timer_create.2:92
8153 "As well as the above values, I<clockid> can be specified as the I<clockid> "
8154 "returned by a call to B<clock_getcpuclockid>(3) or "
8155 "B<pthread_getcpuclockid>(3)."
8159 #: build/C/man2/timer_create.2:101
8161 "The I<sevp> argument points to a I<sigevent> structure that specifies how "
8162 "the caller should be notified when the timer expires. For the definition "
8163 "and general details of this structure, see B<sigevent>(7)."
8167 #: build/C/man2/timer_create.2:105
8168 msgid "The I<sevp.sigev_notify> field can have the following values:"
8172 #: build/C/man2/timer_create.2:110
8174 "Don't asynchronously notify when the timer expires. Progress of the timer "
8175 "can be monitored using B<timer_gettime>(2)."
8179 #: build/C/man2/timer_create.2:128
8181 "Upon timer expiration, generate the signal I<sigev_signo> for the process. "
8182 "See B<sigevent>(7) for general details. The I<si_code> field of the "
8183 "I<siginfo_t> structure will be set to B<SI_TIMER>. At any point in time, at "
8184 "most one signal is queued to the process for a given timer; see "
8185 "B<timer_getoverrun>(2) for more details."
8189 #: build/C/man2/timer_create.2:136
8191 "Upon timer expiration, invoke I<sigev_notify_function> as if it were the "
8192 "start function of a new thread. See B<sigevent>(7) for details."
8196 #: build/C/man2/timer_create.2:150
8198 "As for B<SIGEV_SIGNAL>, but the signal is targeted at the thread whose ID is "
8199 "given in I<sigev_notify_thread_id>, which must be a thread in the same "
8200 "process as the caller. The I<sigev_notify_thread_id> field specifies a "
8201 "kernel thread ID, that is, the value returned by B<clone>(2) or "
8202 "B<gettid>(2). This flag is only intended for use by threading libraries."
8206 #: build/C/man2/timer_create.2:165
8208 "Specifying I<sevp> as NULL is equivalent to specifying a pointer to a "
8209 "I<sigevent> structure in which I<sigev_notify> is B<SIGEV_SIGNAL>, "
8210 "I<sigev_signo> is B<SIGALRM>, and I<sigev_value.sival_int> is the timer ID."
8214 #: build/C/man2/timer_create.2:173
8216 "On success, B<timer_create>() returns 0, and the ID of the new timer is "
8217 "placed in I<*timerid>. On failure, -1 is returned, and I<errno> is set to "
8218 "indicate the error."
8222 #: build/C/man2/timer_create.2:177
8223 msgid "Temporary error during kernel allocation of timer structures."
8227 #: build/C/man2/timer_create.2:185
8229 "Clock ID, I<sigev_notify>, I<sigev_signo>, or I<sigev_notify_thread_id> is "
8233 #. glibc layer: malloc()
8235 #: build/C/man2/timer_create.2:189
8236 msgid "Could not allocate memory."
8240 #: build/C/man2/timer_create.2:191 build/C/man2/timer_delete.2:64 build/C/man2/timer_getoverrun.2:94
8241 msgid "This system call is available since Linux 2.6."
8245 #: build/C/man2/timer_create.2:196
8246 msgid "A program may create multiple interval timers using B<timer_create>()."
8250 #: build/C/man2/timer_create.2:201
8252 "Timers are not inherited by the child of a B<fork>(2), and are disarmed and "
8253 "deleted during an B<execve>(2)."
8257 #: build/C/man2/timer_create.2:209
8259 "The kernel preallocates a \"queued real-time signal\" for each timer created "
8260 "using B<timer_create>(). Consequently, the number of timers is limited by "
8261 "the B<RLIMIT_SIGPENDING> resource limit (see B<setrlimit>(2))."
8265 #: build/C/man2/timer_create.2:214
8267 "The timers created by B<timer_create>() are commonly known as \"POSIX "
8268 "(interval) timers\". The POSIX timers API consists of the following "
8273 #: build/C/man2/timer_create.2:217
8274 msgid "B<timer_create>(): Create a timer."
8278 #: build/C/man2/timer_create.2:220
8279 msgid "B<timer_settime>(2): Arm (start) or disarm (stop) a timer."
8283 #: build/C/man2/timer_create.2:224
8285 "B<timer_gettime>(2): Fetch the time remaining until the next expiration of a "
8286 "timer, along with the interval setting of the timer."
8290 #: build/C/man2/timer_create.2:227
8292 "B<timer_getoverrun>(2): Return the overrun count for the last timer "
8297 #: build/C/man2/timer_create.2:230
8298 msgid "B<timer_delete>(2): Disarm and delete a timer."
8302 #: build/C/man2/timer_create.2:233
8304 "Part of the implementation of the POSIX timers API is provided by glibc. In "
8309 #: build/C/man2/timer_create.2:237
8311 "The functionality for B<SIGEV_THREAD> is implemented within glibc, rather "
8315 #. See the glibc source file kernel-posix-timers.h for the structure
8316 #. that glibc uses to map userspace timer IDs to kernel timer IDs
8317 #. The kernel-level timer ID is exposed via siginfo.si_tid.
8319 #: build/C/man2/timer_create.2:243
8321 "The timer IDs presented at user level are maintained by glibc, which maps "
8322 "these IDs to the timer IDs employed by the kernel."
8326 #: build/C/man2/timer_create.2:251
8328 "The POSIX timers system calls first appeared in Linux 2.6. Prior to this, "
8329 "glibc provided an incomplete userspace implementation (B<CLOCK_REALTIME> "
8330 "timers only) using POSIX threads, and current glibc falls back to this "
8331 "implementation on systems running pre-2.6 Linux kernels."
8335 #: build/C/man2/timer_create.2:263
8337 "The program below takes two arguments: a sleep period in seconds, and a "
8338 "timer frequency in nanoseconds. The program establishes a handler for the "
8339 "signal it uses for the timer, blocks that signal, creates and arms a timer "
8340 "that expires with the given frequency, sleeps for the specified number of "
8341 "seconds, and then unblocks the timer signal. Assuming that the timer "
8342 "expired at least once while the program slept, the signal handler will be "
8343 "invoked, and the handler displays some information about the timer "
8344 "notification. The program terminates after one invocation of the signal "
8349 #: build/C/man2/timer_create.2:268
8351 "In the following example run, the program sleeps for 1 second, after "
8352 "creating a timer that has a frequency of 100 nanoseconds. By the time the "
8353 "signal is unblocked and delivered, there have been around ten million "
8358 #: build/C/man2/timer_create.2:280
8361 "$ B<./a.out 1 100>\n"
8362 "Establishing handler for signal 34\n"
8363 "Blocking signal 34\n"
8364 "timer ID is 0x804c008\n"
8365 "Sleeping for 1 seconds\n"
8366 "Unblocking signal 34\n"
8367 "Caught signal 34\n"
8368 " sival_ptr = 0xbfb174f4; *sival_ptr = 0x804c008\n"
8369 " overrun count = 10004886\n"
8373 #: build/C/man2/timer_create.2:282
8375 msgid "Program Source"
8379 #: build/C/man2/timer_create.2:290
8382 "#include E<lt>stdlib.hE<gt>\n"
8383 "#include E<lt>unistd.hE<gt>\n"
8384 "#include E<lt>stdio.hE<gt>\n"
8385 "#include E<lt>signal.hE<gt>\n"
8386 "#include E<lt>time.hE<gt>\n"
8390 #: build/C/man2/timer_create.2:293
8393 "#define CLOCKID CLOCK_REALTIME\n"
8394 "#define SIG SIGRTMIN\n"
8398 #: build/C/man2/timer_create.2:296
8401 "#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \\e\n"
8406 #: build/C/man2/timer_create.2:302
8410 "print_siginfo(siginfo_t *si)\n"
8417 #: build/C/man2/timer_create.2:304
8419 msgid " tidp = si-E<gt>si_value.sival_ptr;\n"
8423 #: build/C/man2/timer_create.2:307
8426 " printf(\" sival_ptr = %p; \", si-E<gt>si_value.sival_ptr);\n"
8427 " printf(\" *sival_ptr = 0x%lx\\en\", (long) *tidp);\n"
8431 #: build/C/man2/timer_create.2:314
8434 " or = timer_getoverrun(*tidp);\n"
8436 " errExit(\"timer_getoverrun\");\n"
8438 " printf(\" overrun count = %d\\en\", or);\n"
8443 #: build/C/man2/timer_create.2:321
8447 "handler(int sig, siginfo_t *si, void *uc)\n"
8449 " /* Note: calling printf() from a signal handler is not\n"
8450 " strictly correct, since printf() is not async-signal-safe;\n"
8451 " see signal(7) */\n"
8455 #: build/C/man2/timer_create.2:326
8458 " printf(\"Caught signal %d\\en\", sig);\n"
8459 " print_siginfo(si);\n"
8460 " signal(sig, SIG_IGN);\n"
8465 #: build/C/man2/timer_create.2:336
8469 "main(int argc, char *argv[])\n"
8471 " timer_t timerid;\n"
8472 " struct sigevent sev;\n"
8473 " struct itimerspec its;\n"
8474 " long long freq_nanosecs;\n"
8476 " struct sigaction sa;\n"
8480 #: build/C/man2/timer_create.2:342
8483 " if (argc != 3) {\n"
8484 " fprintf(stderr, \"Usage: %s E<lt>sleep-secsE<gt> "
8485 "E<lt>freq-nanosecsE<gt>\\en\",\n"
8487 " exit(EXIT_FAILURE);\n"
8492 #: build/C/man2/timer_create.2:344
8494 msgid " /* Establish handler for timer signal */\n"
8498 #: build/C/man2/timer_create.2:351
8501 " printf(\"Establishing handler for signal %d\\en\", SIG);\n"
8502 " sa.sa_flags = SA_SIGINFO;\n"
8503 " sa.sa_sigaction = handler;\n"
8504 " sigemptyset(&sa.sa_mask);\n"
8505 " if (sigaction(SIG, &sa, NULL) == -1)\n"
8506 " errExit(\"sigaction\");\n"
8510 #: build/C/man2/timer_create.2:353
8512 msgid " /* Block timer signal temporarily */\n"
8516 #: build/C/man2/timer_create.2:359
8519 " printf(\"Blocking signal %d\\en\", SIG);\n"
8520 " sigemptyset(&mask);\n"
8521 " sigaddset(&mask, SIG);\n"
8522 " if (sigprocmask(SIG_SETMASK, &mask, NULL) == -1)\n"
8523 " errExit(\"sigprocmask\");\n"
8527 #: build/C/man2/timer_create.2:361
8529 msgid " /* Create the timer */\n"
8533 #: build/C/man2/timer_create.2:367
8536 " sev.sigev_notify = SIGEV_SIGNAL;\n"
8537 " sev.sigev_signo = SIG;\n"
8538 " sev.sigev_value.sival_ptr = &timerid;\n"
8539 " if (timer_create(CLOCKID, &sev, &timerid) == -1)\n"
8540 " errExit(\"timer_create\");\n"
8544 #: build/C/man2/timer_create.2:369
8546 msgid " printf(\"timer ID is 0x%lx\\en\", (long) timerid);\n"
8550 #: build/C/man2/timer_create.2:371
8552 msgid " /* Start the timer */\n"
8556 #: build/C/man2/timer_create.2:377
8559 " freq_nanosecs = atoll(argv[2]);\n"
8560 " its.it_value.tv_sec = freq_nanosecs / 1000000000;\n"
8561 " its.it_value.tv_nsec = freq_nanosecs % 1000000000;\n"
8562 " its.it_interval.tv_sec = its.it_value.tv_sec;\n"
8563 " its.it_interval.tv_nsec = its.it_value.tv_nsec;\n"
8567 #: build/C/man2/timer_create.2:380
8570 " if (timer_settime(timerid, 0, &its, NULL) == -1)\n"
8571 " errExit(\"timer_settime\");\n"
8575 #: build/C/man2/timer_create.2:383
8578 " /* Sleep for a while; meanwhile, the timer may expire\n"
8579 " multiple times */\n"
8583 #: build/C/man2/timer_create.2:386
8586 " printf(\"Sleeping for %d seconds\\en\", atoi(argv[1]));\n"
8587 " sleep(atoi(argv[1]));\n"
8591 #: build/C/man2/timer_create.2:389
8594 " /* Unlock the timer signal, so that timer notification\n"
8595 " can be delivered */\n"
8599 #: build/C/man2/timer_create.2:393
8602 " printf(\"Unblocking signal %d\\en\", SIG);\n"
8603 " if (sigprocmask(SIG_UNBLOCK, &mask, NULL) == -1)\n"
8604 " errExit(\"sigprocmask\");\n"
8608 #: build/C/man2/timer_create.2:396 build/C/man2/timerfd_create.2:533
8611 " exit(EXIT_SUCCESS);\n"
8616 #: build/C/man2/timer_create.2:409
8618 "B<clock_gettime>(2), B<setitimer>(2), B<timer_delete>(2), "
8619 "B<timer_getoverrun>(2), B<timer_settime>(2), B<timerfd_create>(2), "
8620 "B<clock_getcpuclockid>(3), B<pthread_getcpuclockid>(3), B<pthreads>(7), "
8621 "B<sigevent>(7), B<signal>(7), B<time>(7)"
8625 #: build/C/man2/timer_delete.2:23
8627 msgid "TIMER_DELETE"
8631 #: build/C/man2/timer_delete.2:23 build/C/man2/timer_getoverrun.2:23 build/C/man2/timer_settime.2:23
8637 #: build/C/man2/timer_delete.2:26
8638 msgid "timer_delete - delete a POSIX per-process timer"
8642 #: build/C/man2/timer_delete.2:29 build/C/man2/timer_getoverrun.2:29 build/C/man2/timer_settime.2:30
8644 msgid "B<#include E<lt>time.hE<gt>>\n"
8648 #: build/C/man2/timer_delete.2:31
8650 msgid "B<int timer_delete(timer_t >I<timerid>B<);>\n"
8654 #: build/C/man2/timer_delete.2:42
8655 msgid "B<timer_delete>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
8659 #: build/C/man2/timer_delete.2:50
8661 "B<timer_delete>() deletes the timer whose ID is given in I<timerid>. If "
8662 "the timer was armed at the time of this call, it is disarmed before being "
8663 "deleted. The treatment of any pending signal generated by the deleted timer "
8668 #: build/C/man2/timer_delete.2:57
8670 "On success, B<timer_delete>() returns 0. On failure, -1 is returned, and "
8671 "I<errno> is set to indicate the error."
8675 #: build/C/man2/timer_delete.2:62 build/C/man2/timer_getoverrun.2:92
8676 msgid "I<timerid> is not a valid timer ID."
8680 #: build/C/man2/timer_delete.2:71
8682 "B<clock_gettime>(2), B<timer_create>(2), B<timer_getoverrun>(2), "
8683 "B<timer_settime>(2), B<time>(7)"
8687 #: build/C/man2/timer_getoverrun.2:23
8689 msgid "TIMER_GETOVERRUN"
8693 #: build/C/man2/timer_getoverrun.2:26
8694 msgid "timer_getoverrun - get overrun count for a POSIX per-process timer"
8698 #: build/C/man2/timer_getoverrun.2:31
8700 msgid "B<int timer_getoverrun(timer_t >I<timerid>B<);>\n"
8704 #: build/C/man2/timer_getoverrun.2:42
8705 msgid "B<timer_getoverrun>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
8709 #: build/C/man2/timer_getoverrun.2:53
8711 "B<timer_getoverrun>() returns the \"overrun count\" for the timer referred "
8712 "to by I<timerid>. An application can use the overrun count to accurately "
8713 "calculate the number of timer expirations that would have occurred over a "
8714 "given time interval. Timer overruns can occur both when receiving "
8715 "expiration notifications via signals (B<SIGEV_SIGNAL>), and via threads "
8716 "(B<SIGEV_THREAD>)."
8720 #: build/C/man2/timer_getoverrun.2:73
8722 "When expiration notifications are delivered via a signal, overruns can occur "
8723 "as follows. Regardless of whether or not a real-time signal is used for "
8724 "timer notifications, the system queues at most one signal per timer. (This "
8725 "is the behavior specified by POSIX.1-2001. The alternative, queuing one "
8726 "signal for each timer expiration, could easily result in overflowing the "
8727 "allowed limits for queued signals on the system.) Because of system "
8728 "scheduling delays, or because the signal may be temporarily blocked, there "
8729 "can be a delay between the time when the notification signal is generated "
8730 "and the time when it is delivered (e.g., caught by a signal handler) or "
8731 "accepted (e.g., using B<sigwaitinfo>(2)). In this interval, further timer "
8732 "expirations may occur. The timer overrun count is the number of additional "
8733 "timer expirations that occurred between the time when the signal was "
8734 "generated and when it was delivered or accepted."
8738 #: build/C/man2/timer_getoverrun.2:79
8740 "Timer overruns can also occur when expiration notifications are delivered "
8741 "via invocation of a thread, since there may be an arbitrary delay between an "
8742 "expiration of the timer and the invocation of the notification thread, and "
8743 "in that delay interval, additional timer expirations may occur"
8747 #: build/C/man2/timer_getoverrun.2:87
8749 "On success, B<timer_getoverrun>() returns the overrun count of the "
8750 "specified timer; this count may be 0 if no overruns have occurred. On "
8751 "failure, -1 is returned, and I<errno> is set to indicate the error."
8755 #: build/C/man2/timer_getoverrun.2:108
8757 "When timer notifications are delivered via signals (B<SIGEV_SIGNAL>), on "
8758 "Linux it is also possible to obtain the overrun count via the I<si_overrun> "
8759 "field of the I<siginfo_t> structure (see B<sigaction>(2)). This allows an "
8760 "application to avoid the overhead of making a system call to obtain the "
8761 "overrun count, but is a nonportable extension to POSIX.1-2001."
8764 #. FIXME . Austin bug filed, 11 Feb 09
8766 #: build/C/man2/timer_getoverrun.2:112
8768 "POSIX.1-2001 only discusses timer overruns in the context of timer "
8769 "notifications using signals."
8772 #. Bug filed: http://bugzilla.kernel.org/show_bug.cgi?id=12665
8773 #. http://thread.gmane.org/gmane.linux.kernel/113276/
8775 #: build/C/man2/timer_getoverrun.2:125
8777 "POSIX.1-2001 specifies that if the timer overrun count is equal to or "
8778 "greater than an implementation-defined maximum, B<DELAYTIMER_MAX>, then "
8779 "B<timer_getoverrun>() should return B<DELAYTIMER_MAX>. However, Linux does "
8780 "not implement this feature: instead, if the timer overrun value exceeds the "
8781 "maximum representable integer, the counter cycles, starting once more from "
8786 #: build/C/man2/timer_getoverrun.2:128 build/C/man2/timer_settime.2:208
8787 msgid "See B<timer_create>(2)."
8791 #: build/C/man2/timer_getoverrun.2:137
8793 "B<clock_gettime>(2), B<sigaction>(2), B<signalfd>(2), B<sigwaitinfo>(2), "
8794 "B<timer_create>(2), B<timer_delete>(2), B<timer_settime>(2), B<signal>(7), "
8799 #: build/C/man2/timer_settime.2:23
8801 msgid "TIMER_SETTIME"
8805 #: build/C/man2/timer_settime.2:27
8807 "timer_settime, timer_gettime - arm/disarm and fetch state of POSIX "
8812 #: build/C/man2/timer_settime.2:35
8815 "B<int timer_settime(timer_t >I<timerid>B<, int >I<flags>B<,>\n"
8816 "B< const struct itimerspec *>I<new_value>B<,>\n"
8817 "B< struct itimerspec * >I<old_value>B<);>\n"
8818 "B<int timer_gettime(timer_t >I<timerid>B<, struct itimerspec "
8819 "*>I<curr_value>B<);>\n"
8823 #: build/C/man2/timer_settime.2:47
8824 msgid "B<timer_settime>(), B<timer_gettime>(): _POSIX_C_SOURCE\\ E<gt>=\\ 199309L"
8828 #: build/C/man2/timer_settime.2:60
8830 "B<timer_settime>() arms or disarms the timer identified by I<timerid>. The "
8831 "I<new_value> argument is an I<itimerspec> structure that specifies the new "
8832 "initial value and the new interval for the timer. The I<itimerspec> "
8833 "structure is defined as follows:"
8837 #: build/C/man2/timer_settime.2:67 build/C/man2/timerfd_create.2:127
8840 "struct timespec {\n"
8841 " time_t tv_sec; /* Seconds */\n"
8842 " long tv_nsec; /* Nanoseconds */\n"
8847 #: build/C/man2/timer_settime.2:72
8850 "struct itimerspec {\n"
8851 " struct timespec it_interval; /* Timer interval */\n"
8852 " struct timespec it_value; /* Initial expiration */\n"
8857 #: build/C/man2/timer_settime.2:84
8859 "Each of the substructures of the I<itimerspec> structure is a I<timespec> "
8860 "structure that allows a time value to be specified in seconds and "
8861 "nanoseconds. These time values are measured according to the clock that was "
8862 "specified when the timer was created by B<timer_create>(2)"
8866 #: build/C/man2/timer_settime.2:98
8868 "If I<new_value-E<gt>it_value> specifies a nonzero value (i.e., either "
8869 "subfield is nonzero), then B<timer_settime>() arms (starts) the timer, "
8870 "setting it to initially expire at the given time. (If the timer was already "
8871 "armed, then the previous settings are overwritten.) If "
8872 "I<new_value-E<gt>it_value> specifies a zero value (i.e., both subfields are "
8873 "zero), then the timer is disarmed."
8877 #: build/C/man2/timer_settime.2:110
8879 "The I<new_value-E<gt>it_interval> field specifies the period of the timer, "
8880 "in seconds and nanoseconds. If this field is nonzero, then each time that "
8881 "an armed timer expires, the timer is reloaded from the value specified in "
8882 "I<new_value-E<gt>it_interval>. If I<new_value-E<gt>it_interval> specifies a "
8883 "zero value then the timer expires just once, at the time specified by "
8887 #. By experiment: the overrun count is set correctly, for CLOCK_REALTIME.
8889 #: build/C/man2/timer_settime.2:131
8891 "By default, the initial expiration time specified in "
8892 "I<new_value-E<gt>it_value> is interpreted relative to the current time on "
8893 "the timer's clock at the time of the call. This can be modified by "
8894 "specifying B<TIMER_ABSTIME> in I<flags>, in which case "
8895 "I<new_value-E<gt>it_value> is interpreted as an absolute value as measured "
8896 "on the timer's clock; that is, the timer will expire when the clock value "
8897 "reaches the value specified by I<new_value-E<gt>it_value>. If the specified "
8898 "absolute time has already passed, then the timer expires immediately, and "
8899 "the overrun count (see B<timer_getoverrun>(2)) will be set correctly."
8902 #. Similar remarks might apply with respect to process and thread CPU time
8903 #. clocks, but these clocks are not currently (2.6.28) settable on Linux.
8905 #: build/C/man2/timer_settime.2:141
8907 "If the value of the B<CLOCK_REALTIME> clock is adjusted while an absolute "
8908 "timer based on that clock is armed, then the expiration of the timer will be "
8909 "appropriately adjusted. Adjustments to the B<CLOCK_REALTIME> clock have no "
8910 "effect on relative timers based on that clock."
8914 #: build/C/man2/timer_settime.2:149
8916 "If I<old_value> is not NULL, then it returns the previous interval of the "
8917 "timer (in I<old_value-E<gt>it_interval>) and the amount of time until the "
8918 "timer would previously have next expired (in I<old_value-E<gt>it_value>)."
8922 #: build/C/man2/timer_settime.2:169
8924 "B<timer_gettime>() returns the time until next expiration, and the "
8925 "interval, for the timer specified by I<timerid>, in the buffer pointed to by "
8926 "I<curr_value>. The time remaining until the next timer expiration is "
8927 "returned in I<curr_value-E<gt>it_value>; this is always a relative value, "
8928 "regardless of whether the B<TIMER_ABSTIME> flag was used when arming the "
8929 "timer. If the value returned in I<curr_value-E<gt>it_value> is zero, then "
8930 "the timer is currently disarmed. The timer interval is returned in "
8931 "I<curr_value-E<gt>it_interval>. If the value returned in "
8932 "I<curr_value-E<gt>it_interval> is zero, then this is a \"one-shot\" timer."
8936 #: build/C/man2/timer_settime.2:178
8938 "On success, B<timer_settime>() and B<timer_gettime>() return 0. On error, "
8939 "-1 is returned, and I<errno> is set to indicate the error."
8943 #: build/C/man2/timer_settime.2:180
8944 msgid "These functions may fail with the following errors:"
8948 #: build/C/man2/timer_settime.2:187
8949 msgid "I<new_value>, I<old_value>, or I<curr_value> is not a valid pointer."
8952 #. FIXME . eventually: invalid value in flags
8954 #: build/C/man2/timer_settime.2:192
8955 msgid "I<timerid> is invalid."
8959 #: build/C/man2/timer_settime.2:195
8960 msgid "B<timer_settime>() may fail with the following errors:"
8964 #: build/C/man2/timer_settime.2:201
8966 "I<new_value.it_value> is negative; or I<new_value.it_value.tv_nsec> is "
8967 "negative or greater than 999,999,999."
8971 #: build/C/man2/timer_settime.2:203
8972 msgid "These system calls are available since Linux 2.6."
8976 #: build/C/man2/timer_settime.2:211
8977 msgid "B<timer_create>(2), B<timer_getoverrun>(2), B<time>(7)"
8981 #: build/C/man2/timerfd_create.2:20
8983 msgid "TIMERFD_CREATE"
8987 #: build/C/man2/timerfd_create.2:20
8993 #: build/C/man2/timerfd_create.2:24
8995 "timerfd_create, timerfd_settime, timerfd_gettime - timers that notify via "
9000 #: build/C/man2/timerfd_create.2:27
9002 msgid "B<#include E<lt>sys/timerfd.hE<gt>>\n"
9006 #: build/C/man2/timerfd_create.2:29
9008 msgid "B<int timerfd_create(int >I<clockid>B<, int >I<flags>B<);>\n"
9012 #: build/C/man2/timerfd_create.2:33
9015 "B<int timerfd_settime(int >I<fd>B<, int >I<flags>B<,>\n"
9016 "B< const struct itimerspec *>I<new_value>B<,>\n"
9017 "B< struct itimerspec *>I<old_value>B<);>\n"
9021 #: build/C/man2/timerfd_create.2:35
9023 msgid "B<int timerfd_gettime(int >I<fd>B<, struct itimerspec *>I<curr_value>B<);>\n"
9027 #: build/C/man2/timerfd_create.2:48
9029 "These system calls create and operate on a timer that delivers timer "
9030 "expiration notifications via a file descriptor. They provide an alternative "
9031 "to the use of B<setitimer>(2) or B<timer_create>(2), with the advantage "
9032 "that the file descriptor may be monitored by B<select>(2), B<poll>(2), and "
9037 #: build/C/man2/timerfd_create.2:60
9039 "The use of these three system calls is analogous to the use of "
9040 "B<timer_create>(2), B<timer_settime>(2), and B<timer_gettime>(2). (There is "
9041 "no analog of B<timer_getoverrun>(2), since that functionality is provided by "
9042 "B<read>(2), as described below.)"
9046 #: build/C/man2/timerfd_create.2:60
9048 msgid "timerfd_create()"
9052 #: build/C/man2/timerfd_create.2:79
9054 "B<timerfd_create>() creates a new timer object, and returns a file "
9055 "descriptor that refers to that timer. The I<clockid> argument specifies the "
9056 "clock that is used to mark the progress of the timer, and must be either "
9057 "B<CLOCK_REALTIME> or B<CLOCK_MONOTONIC>. B<CLOCK_REALTIME> is a settable "
9058 "system-wide clock. B<CLOCK_MONOTONIC> is a nonsettable clock that is not "
9059 "affected by discontinuous changes in the system clock (e.g., manual changes "
9060 "to system time). The current value of each of these clocks can be retrieved "
9061 "using B<clock_gettime>(2)."
9065 #: build/C/man2/timerfd_create.2:84
9067 "Starting with Linux 2.6.27, the following values may be bitwise ORed in "
9068 "I<flags> to change the behavior of B<timerfd_create>():"
9072 #: build/C/man2/timerfd_create.2:84
9074 msgid "B<TFD_NONBLOCK>"
9078 #: build/C/man2/timerfd_create.2:92
9080 msgid "B<TFD_CLOEXEC>"
9084 #: build/C/man2/timerfd_create.2:106
9086 "In Linux versions up to and including 2.6.26, I<flags> must be specified as "
9091 #: build/C/man2/timerfd_create.2:106
9093 msgid "timerfd_settime()"
9097 #: build/C/man2/timerfd_create.2:111
9099 "B<timerfd_settime>() arms (starts) or disarms (stops) the timer referred "
9100 "to by the file descriptor I<fd>."
9104 #: build/C/man2/timerfd_create.2:120
9106 "The I<new_value> argument specifies the initial expiration and interval for "
9107 "the timer. The I<itimer> structure used for this argument contains two "
9108 "fields, each of which is in turn a structure of type I<timespec>:"
9112 #: build/C/man2/timerfd_create.2:132
9115 "struct itimerspec {\n"
9116 " struct timespec it_interval; /* Interval for periodic timer */\n"
9117 " struct timespec it_value; /* Initial expiration */\n"
9122 #: build/C/man2/timerfd_create.2:144
9124 "I<new_value.it_value> specifies the initial expiration of the timer, in "
9125 "seconds and nanoseconds. Setting either field of I<new_value.it_value> to a "
9126 "nonzero value arms the timer. Setting both fields of I<new_value.it_value> "
9127 "to zero disarms the timer."
9131 #: build/C/man2/timerfd_create.2:153
9133 "Setting one or both fields of I<new_value.it_interval> to nonzero values "
9134 "specifies the period, in seconds and nanoseconds, for repeated timer "
9135 "expirations after the initial expiration. If both fields of "
9136 "I<new_value.it_interval> are zero, the timer expires just once, at the time "
9137 "specified by I<new_value.it_value>."
9141 #: build/C/man2/timerfd_create.2:169
9143 "The I<flags> argument is either 0, to start a relative timer "
9144 "(I<new_value.it_value> specifies a time relative to the current value of the "
9145 "clock specified by I<clockid>), or B<TFD_TIMER_ABSTIME>, to start an "
9146 "absolute timer (I<new_value.it_value> specifies an absolute time for the "
9147 "clock specified by I<clockid>; that is, the timer will expire when the value "
9148 "of that clock reaches the value specified in I<new_value.it_value>)."
9152 #: build/C/man2/timerfd_create.2:180
9154 "If the I<old_value> argument is not NULL, then the I<itimerspec> structure "
9155 "that it points to is used to return the setting of the timer that was "
9156 "current at the time of the call; see the description of B<timerfd_gettime>() "
9161 #: build/C/man2/timerfd_create.2:180
9163 msgid "timerfd_gettime()"
9167 #: build/C/man2/timerfd_create.2:189
9169 "B<timerfd_gettime>() returns, in I<curr_value>, an I<itimerspec> structure "
9170 "that contains the current setting of the timer referred to by the file "
9175 #: build/C/man2/timerfd_create.2:199
9177 "The I<it_value> field returns the amount of time until the timer will next "
9178 "expire. If both fields of this structure are zero, then the timer is "
9179 "currently disarmed. This field always contains a relative value, regardless "
9180 "of whether the B<TFD_TIMER_ABSTIME> flag was specified when setting the "
9185 #: build/C/man2/timerfd_create.2:206
9187 "The I<it_interval> field returns the interval of the timer. If both fields "
9188 "of this structure are zero, then the timer is set to expire just once, at "
9189 "the time specified by I<curr_value.it_value>."
9193 #: build/C/man2/timerfd_create.2:206
9195 msgid "Operating on a timer file descriptor"
9199 #: build/C/man2/timerfd_create.2:210
9201 "The file descriptor returned by B<timerfd_create>() supports the following "
9206 #: build/C/man2/timerfd_create.2:224
9208 "If the timer has already expired one or more times since its settings were "
9209 "last modified using B<timerfd_settime>(), or since the last successful "
9210 "B<read>(2), then the buffer given to B<read>(2) returns an unsigned 8-byte "
9211 "integer (I<uint64_t>) containing the number of expirations that have "
9212 "occurred. (The returned value is in host byte order, i.e., the native byte "
9213 "order for integers on the host machine.)"
9217 #: build/C/man2/timerfd_create.2:237
9219 "If no timer expirations have occurred at the time of the B<read>(2), then "
9220 "the call either blocks until the next timer expiration, or fails with the "
9221 "error B<EAGAIN> if the file descriptor has been made nonblocking (via the "
9222 "use of the B<fcntl>(2) B<F_SETFL> operation to set the B<O_NONBLOCK> flag)."
9226 #: build/C/man2/timerfd_create.2:243
9228 "A B<read>(2) will fail with the error B<EINVAL> if the size of the supplied "
9229 "buffer is less than 8 bytes."
9233 #: build/C/man2/timerfd_create.2:254
9235 "The file descriptor is readable (the B<select>(2) I<readfds> argument; the "
9236 "B<poll>(2) B<POLLIN> flag) if one or more timer expirations have occurred."
9240 #: build/C/man2/timerfd_create.2:261
9242 "The file descriptor also supports the other file-descriptor multiplexing "
9243 "APIs: B<pselect>(2), B<ppoll>(2), and B<epoll>(7)."
9247 #: build/C/man2/timerfd_create.2:268
9249 "When the file descriptor is no longer required it should be closed. When "
9250 "all file descriptors associated with the same timer object have been closed, "
9251 "the timer is disarmed and its resources are freed by the kernel."
9255 #: build/C/man2/timerfd_create.2:280
9257 "After a B<fork>(2), the child inherits a copy of the file descriptor created "
9258 "by B<timerfd_create>(). The file descriptor refers to the same underlying "
9259 "timer object as the corresponding file descriptor in the parent, and "
9260 "B<read>(2)s in the child will return information about expirations of the "
9265 #: build/C/man2/timerfd_create.2:286
9267 "A file descriptor created by B<timerfd_create>() is preserved across "
9268 "B<execve>(2), and continues to generate timer expirations if the timer was "
9273 #: build/C/man2/timerfd_create.2:293
9275 "On success, B<timerfd_create>() returns a new file descriptor. On error, "
9276 "-1 is returned and I<errno> is set to indicate the error."
9280 #: build/C/man2/timerfd_create.2:301
9282 "B<timerfd_settime>() and B<timerfd_gettime>() return 0 on success; on "
9283 "error they return -1, and set I<errno> to indicate the error."
9287 #: build/C/man2/timerfd_create.2:304
9288 msgid "B<timerfd_create>() can fail with the following errors:"
9292 #: build/C/man2/timerfd_create.2:312
9293 msgid "The I<clockid> argument is neither B<CLOCK_MONOTONIC> nor B<CLOCK_REALTIME>;"
9297 #: build/C/man2/timerfd_create.2:332
9298 msgid "There was insufficient kernel memory to create the timer."
9302 #: build/C/man2/timerfd_create.2:337
9304 "B<timerfd_settime>() and B<timerfd_gettime>() can fail with the following "
9309 #: build/C/man2/timerfd_create.2:341
9310 msgid "I<fd> is not a valid file descriptor."
9314 #: build/C/man2/timerfd_create.2:352
9315 msgid "I<fd> is not a valid timerfd file descriptor."
9319 #: build/C/man2/timerfd_create.2:355
9320 msgid "B<timerfd_settime>() can also fail with the following errors:"
9324 #: build/C/man2/timerfd_create.2:361
9326 "I<new_value> is not properly initialized (one of the I<tv_nsec> falls "
9327 "outside the range zero to 999,999,999)."
9330 #. This case only checked since 2.6.29, and 2.2.2[78].some-stable-version.
9331 #. In older kernel versions, no check was made for invalid flags.
9333 #: build/C/man2/timerfd_create.2:367
9334 msgid "I<flags> is invalid."
9338 #: build/C/man2/timerfd_create.2:370
9340 "These system calls are available on Linux since kernel 2.6.25. Library "
9341 "support is provided by glibc since version 2.8."
9345 #: build/C/man2/timerfd_create.2:381
9347 "The following program creates a timer and then monitors its progress. The "
9348 "program accepts up to three command-line arguments. The first argument "
9349 "specifies the number of seconds for the initial expiration of the timer. "
9350 "The second argument specifies the interval for the timer, in seconds. The "
9351 "third argument specifies the number of times the program should allow the "
9352 "timer to expire before terminating. The second and third command-line "
9353 "arguments are optional."
9357 #: build/C/man2/timerfd_create.2:383 build/C/man2/wait.2:541
9358 msgid "The following shell session demonstrates the use of the program:"
9362 #: build/C/man2/timerfd_create.2:398
9365 "$B< a.out 3 1 100>\n"
9366 "0.000: timer started\n"
9367 "3.000: read: 1; total=1\n"
9368 "4.000: read: 1; total=2\n"
9369 "B<^Z > # type control-Z to suspend the program\n"
9370 "[1]+ Stopped ./timerfd3_demo 3 1 100\n"
9371 "$ B<fg> # Resume execution after a few seconds\n"
9373 "9.660: read: 5; total=7\n"
9374 "10.000: read: 1; total=8\n"
9375 "11.000: read: 1; total=9\n"
9376 "B<^C > # type control-C to suspend the program\n"
9379 #. The commented out code here is what we currently need until
9380 #. the required stuff is in glibc
9383 #. /* Link with -lrt */
9384 #. #define _GNU_SOURCE
9385 #. #include <sys/syscall.h>
9386 #. #include <unistd.h>
9387 #. #include <time.h>
9388 #. #if defined(__i386__)
9389 #. #define __NR_timerfd_create 322
9390 #. #define __NR_timerfd_settime 325
9391 #. #define __NR_timerfd_gettime 326
9395 #. timerfd_create(int clockid, int flags)
9397 #. return syscall(__NR_timerfd_create, clockid, flags);
9401 #. timerfd_settime(int fd, int flags, struct itimerspec *new_value,
9402 #. struct itimerspec *curr_value)
9404 #. return syscall(__NR_timerfd_settime, fd, flags, new_value,
9409 #. timerfd_gettime(int fd, struct itimerspec *curr_value)
9411 #. return syscall(__NR_timerfd_gettime, fd, curr_value);
9414 #. #define TFD_TIMER_ABSTIME (1 << 0)
9416 #. ////////////////////////////////////////////////////////////
9418 #: build/C/man2/timerfd_create.2:447
9421 "#include E<lt>sys/timerfd.hE<gt>\n"
9422 "#include E<lt>time.hE<gt>\n"
9423 "#include E<lt>unistd.hE<gt>\n"
9424 "#include E<lt>stdlib.hE<gt>\n"
9425 "#include E<lt>stdio.hE<gt>\n"
9426 "#include E<lt>stdint.hE<gt> /* Definition of uint64_t */\n"
9430 #: build/C/man2/timerfd_create.2:450
9433 "#define handle_error(msg) \\e\n"
9434 " do { perror(msg); exit(EXIT_FAILURE); } while (0)\n"
9438 #: build/C/man2/timerfd_create.2:458
9442 "print_elapsed_time(void)\n"
9444 " static struct timespec start;\n"
9445 " struct timespec curr;\n"
9446 " static int first_call = 1;\n"
9447 " int secs, nsecs;\n"
9451 #: build/C/man2/timerfd_create.2:464
9454 " if (first_call) {\n"
9455 " first_call = 0;\n"
9456 " if (clock_gettime(CLOCK_MONOTONIC, &start) == -1)\n"
9457 " handle_error(\"clock_gettime\");\n"
9462 #: build/C/man2/timerfd_create.2:467
9465 " if (clock_gettime(CLOCK_MONOTONIC, &curr) == -1)\n"
9466 " handle_error(\"clock_gettime\");\n"
9470 #: build/C/man2/timerfd_create.2:476
9473 " secs = curr.tv_sec - start.tv_sec;\n"
9474 " nsecs = curr.tv_nsec - start.tv_nsec;\n"
9475 " if (nsecs E<lt> 0) {\n"
9477 " nsecs += 1000000000;\n"
9479 " printf(\"%d.%03d: \", secs, (nsecs + 500000) / 1000000);\n"
9484 #: build/C/man2/timerfd_create.2:485
9488 "main(int argc, char *argv[])\n"
9490 " struct itimerspec new_value;\n"
9491 " int max_exp, fd;\n"
9492 " struct timespec now;\n"
9493 " uint64_t exp, tot_exp;\n"
9498 #: build/C/man2/timerfd_create.2:491
9501 " if ((argc != 2) && (argc != 4)) {\n"
9502 " fprintf(stderr, \"%s init-secs [interval-secs max-exp]\\en\",\n"
9504 " exit(EXIT_FAILURE);\n"
9509 #: build/C/man2/timerfd_create.2:494
9512 " if (clock_gettime(CLOCK_REALTIME, &now) == -1)\n"
9513 " handle_error(\"clock_gettime\");\n"
9517 #: build/C/man2/timerfd_create.2:497
9520 " /* Create a CLOCK_REALTIME absolute timer with initial\n"
9521 " expiration and interval as specified in command line */\n"
9525 #: build/C/man2/timerfd_create.2:508
9528 " new_value.it_value.tv_sec = now.tv_sec + atoi(argv[1]);\n"
9529 " new_value.it_value.tv_nsec = now.tv_nsec;\n"
9530 " if (argc == 2) {\n"
9531 " new_value.it_interval.tv_sec = 0;\n"
9534 " new_value.it_interval.tv_sec = atoi(argv[2]);\n"
9535 " max_exp = atoi(argv[3]);\n"
9537 " new_value.it_interval.tv_nsec = 0;\n"
9541 #: build/C/man2/timerfd_create.2:512
9544 " fd = timerfd_create(CLOCK_REALTIME, 0);\n"
9546 " handle_error(\"timerfd_create\");\n"
9550 #: build/C/man2/timerfd_create.2:515
9553 " if (timerfd_settime(fd, TFD_TIMER_ABSTIME, &new_value, NULL) == -1)\n"
9554 " handle_error(\"timerfd_settime\");\n"
9558 #: build/C/man2/timerfd_create.2:518
9561 " print_elapsed_time();\n"
9562 " printf(\"timer started\\en\");\n"
9566 #: build/C/man2/timerfd_create.2:523
9569 " for (tot_exp = 0; tot_exp E<lt> max_exp;) {\n"
9570 " s = read(fd, &exp, sizeof(uint64_t));\n"
9571 " if (s != sizeof(uint64_t))\n"
9572 " handle_error(\"read\");\n"
9576 #: build/C/man2/timerfd_create.2:530
9579 " tot_exp += exp;\n"
9580 " print_elapsed_time();\n"
9581 " printf(\"read: %llu; total=%llu\\en\",\n"
9582 " (unsigned long long) exp,\n"
9583 " (unsigned long long) tot_exp);\n"
9589 #: build/C/man2/timerfd_create.2:540
9591 "Currently, B<timerfd_create>() supports fewer types of clock IDs than "
9592 "B<timer_create>(2)."
9596 #: build/C/man2/timerfd_create.2:551
9598 "B<eventfd>(2), B<poll>(2), B<read>(2), B<select>(2), B<setitimer>(2), "
9599 "B<signalfd>(2), B<timer_create>(2), B<timer_gettime>(2), "
9600 "B<timer_settime>(2), B<epoll>(7), B<time>(7)"
9604 #: build/C/man2/tkill.2:29
9610 #: build/C/man2/tkill.2:32
9611 msgid "tkill, tgkill - send a signal to a thread"
9615 #: build/C/man2/tkill.2:35
9617 msgid "B<int tkill(int >I<tid>B<, int >I<sig>B<);>\n"
9621 #: build/C/man2/tkill.2:37
9623 msgid "B<int tgkill(int >I<tgid>B<, int >I<tid>B<, int >I<sig>B<);>\n"
9627 #: build/C/man2/tkill.2:51
9629 "B<tgkill>() sends the signal I<sig> to the thread with the thread ID I<tid> "
9630 "in the thread group I<tgid>. (By contrast, B<kill>(2) can only be used to "
9631 "send a signal to a process (i.e., thread group) as a whole, and the signal "
9632 "will be delivered to an arbitrary thread within that process.)"
9636 #: build/C/man2/tkill.2:59
9638 "B<tkill>() is an obsolete predecessor to B<tgkill>(). It only allows the "
9639 "target thread ID to be specified, which may result in the wrong thread being "
9640 "signaled if a thread terminates and its thread ID is recycled. Avoid using "
9645 #: build/C/man2/tkill.2:66
9646 msgid "If I<tgid> is specified as -1, B<tgkill>() is equivalent to B<tkill>()."
9650 #: build/C/man2/tkill.2:69
9652 "These are the raw system call interfaces, meant for internal thread library "
9657 #: build/C/man2/tkill.2:77
9658 msgid "An invalid thread ID, thread group ID, or signal was specified."
9662 #: build/C/man2/tkill.2:82
9663 msgid "Permission denied. For the required permissions, see B<kill>(2)."
9667 #: build/C/man2/tkill.2:85
9668 msgid "No process with the specified thread ID (and thread group ID) exists."
9672 #: build/C/man2/tkill.2:90
9674 "B<tkill>() is supported since Linux 2.4.19 / 2.5.4. B<tgkill>() was added "
9679 #: build/C/man2/tkill.2:96
9681 "B<tkill>() and B<tgkill>() are Linux-specific and should not be used in "
9682 "programs that are intended to be portable."
9686 #: build/C/man2/tkill.2:102
9688 "See the description of B<CLONE_THREAD> in B<clone>(2) for an explanation of "
9693 #: build/C/man2/tkill.2:105
9695 "Glibc does not provide wrappers for these system calls; call them using "
9700 #: build/C/man2/tkill.2:109
9701 msgid "B<clone>(2), B<gettid>(2), B<kill>(2), B<rt_sigqueueinfo>(2)"
9705 #: build/C/man2/wait.2:50
9711 #: build/C/man2/wait.2:53
9712 msgid "wait, waitpid, waitid - wait for process to change state"
9716 #: build/C/man2/wait.2:55
9717 msgid "B<#include E<lt>sys/types.hE<gt>>"
9721 #: build/C/man2/wait.2:57
9722 msgid "B<#include E<lt>sys/wait.hE<gt>>"
9726 #: build/C/man2/wait.2:59
9727 msgid "B<pid_t wait(int *>I<status>B<);>"
9731 #: build/C/man2/wait.2:61
9732 msgid "B<pid_t waitpid(pid_t >I<pid>B<, int *>I<status>B<, int >I<options>B<);>"
9736 #: build/C/man2/wait.2:64
9738 "B<int waitid(idtype_t >I<idtype>B<, id_t >I<id>B<, siginfo_t *>I<infop>B<, "
9739 "int >I<options>B<);>"
9743 #: build/C/man2/wait.2:73
9744 msgid "B<waitid>():"
9748 #: build/C/man2/wait.2:77
9750 "_SVID_SOURCE || _XOPEN_SOURCE\\ E<gt>=\\ 500 || _XOPEN_SOURCE\\ &&\\ "
9751 "_XOPEN_SOURCE_EXTENDED"
9755 #: build/C/man2/wait.2:92
9757 "All of these system calls are used to wait for state changes in a child of "
9758 "the calling process, and obtain information about the child whose state has "
9759 "changed. A state change is considered to be: the child terminated; the "
9760 "child was stopped by a signal; or the child was resumed by a signal. In the "
9761 "case of a terminated child, performing a wait allows the system to release "
9762 "the resources associated with the child; if a wait is not performed, then "
9763 "the terminated child remains in a \"zombie\" state (see NOTES below)."
9767 #: build/C/man2/wait.2:104
9769 "If a child has already changed state, then these calls return immediately. "
9770 "Otherwise they block until either a child changes state or a signal handler "
9771 "interrupts the call (assuming that system calls are not automatically "
9772 "restarted using the B<SA_RESTART> flag of B<sigaction>(2)). In the "
9773 "remainder of this page, a child whose state has changed and which has not "
9774 "yet been waited upon by one of these system calls is termed I<waitable>."
9778 #: build/C/man2/wait.2:104
9780 msgid "wait() and waitpid()"
9784 #: build/C/man2/wait.2:112
9786 "The B<wait>() system call suspends execution of the calling process until "
9787 "one of its children terminates. The call I<wait(&status)> is equivalent to:"
9791 #: build/C/man2/wait.2:115
9793 msgid " waitpid(-1, &status, 0);\n"
9797 #: build/C/man2/wait.2:129
9799 "The B<waitpid>() system call suspends execution of the calling process "
9800 "until a child specified by I<pid> argument has changed state. By default, "
9801 "B<waitpid>() waits only for terminated children, but this behavior is "
9802 "modifiable via the I<options> argument, as described below."
9806 #: build/C/man2/wait.2:133
9807 msgid "The value of I<pid> can be:"
9811 #: build/C/man2/wait.2:133
9817 #: build/C/man2/wait.2:137
9819 "meaning wait for any child process whose process group ID is equal to the "
9820 "absolute value of I<pid>."
9824 #: build/C/man2/wait.2:137
9830 #: build/C/man2/wait.2:139
9831 msgid "meaning wait for any child process."
9835 #: build/C/man2/wait.2:139
9841 #: build/C/man2/wait.2:142
9843 "meaning wait for any child process whose process group ID is equal to that "
9844 "of the calling process."
9848 #: build/C/man2/wait.2:142
9854 #: build/C/man2/wait.2:146
9855 msgid "meaning wait for the child whose process ID is equal to the value of I<pid>."
9859 #: build/C/man2/wait.2:150
9860 msgid "The value of I<options> is an OR of zero or more of the following constants:"
9864 #: build/C/man2/wait.2:150 build/C/man2/wait.2:279
9870 #: build/C/man2/wait.2:153
9871 msgid "return immediately if no child has exited."
9875 #: build/C/man2/wait.2:153
9877 msgid "B<WUNTRACED>"
9881 #: build/C/man2/wait.2:162
9883 "also return if a child has stopped (but not traced via B<ptrace>(2)). "
9884 "Status for I<traced> children which have stopped is provided even if this "
9885 "option is not specified."
9889 #: build/C/man2/wait.2:162
9891 msgid "B<WCONTINUED> (since Linux 2.6.10)"
9895 #: build/C/man2/wait.2:166
9896 msgid "also return if a stopped child has been resumed by delivery of B<SIGCONT>."
9900 #: build/C/man2/wait.2:168
9901 msgid "(For Linux-only options, see below.)"
9905 #: build/C/man2/wait.2:182
9907 "If I<status> is not NULL, B<wait>() and B<waitpid>() store status "
9908 "information in the I<int> to which it points. This integer can be inspected "
9909 "with the following macros (which take the integer itself as an argument, not "
9910 "a pointer to it, as is done in B<wait>() and B<waitpid>()!):"
9914 #: build/C/man2/wait.2:182
9916 msgid "B<WIFEXITED(>I<status>B<)>"
9920 #: build/C/man2/wait.2:190
9922 "returns true if the child terminated normally, that is, by calling "
9923 "B<exit>(3) or B<_exit>(2), or by returning from main()."
9927 #: build/C/man2/wait.2:190
9929 msgid "B<WEXITSTATUS(>I<status>B<)>"
9933 #: build/C/man2/wait.2:203
9935 "returns the exit status of the child. This consists of the least "
9936 "significant 8 bits of the I<status> argument that the child specified in a "
9937 "call to B<exit>(3) or B<_exit>(2) or as the argument for a return "
9938 "statement in main(). This macro should only be employed if B<WIFEXITED> "
9943 #: build/C/man2/wait.2:203
9945 msgid "B<WIFSIGNALED(>I<status>B<)>"
9949 #: build/C/man2/wait.2:206
9950 msgid "returns true if the child process was terminated by a signal."
9954 #: build/C/man2/wait.2:206
9956 msgid "B<WTERMSIG(>I<status>B<)>"
9960 #: build/C/man2/wait.2:213
9962 "returns the number of the signal that caused the child process to "
9963 "terminate. This macro should only be employed if B<WIFSIGNALED> returned "
9968 #: build/C/man2/wait.2:213
9970 msgid "B<WCOREDUMP(>I<status>B<)>"
9974 #: build/C/man2/wait.2:222
9976 "returns true if the child produced a core dump. This macro should only be "
9977 "employed if B<WIFSIGNALED> returned true. This macro is not specified in "
9978 "POSIX.1-2001 and is not available on some UNIX implementations (e.g., AIX, "
9979 "SunOS). Only use this enclosed in #ifdef WCOREDUMP ... #endif."
9983 #: build/C/man2/wait.2:222
9985 msgid "B<WIFSTOPPED(>I<status>B<)>"
9989 #: build/C/man2/wait.2:229
9991 "returns true if the child process was stopped by delivery of a signal; this "
9992 "is only possible if the call was done using B<WUNTRACED> or when the child "
9993 "is being traced (see B<ptrace>(2))."
9997 #: build/C/man2/wait.2:229
9999 msgid "B<WSTOPSIG(>I<status>B<)>"
10002 #. type: Plain text
10003 #: build/C/man2/wait.2:235
10005 "returns the number of the signal which caused the child to stop. This macro "
10006 "should only be employed if B<WIFSTOPPED> returned true."
10010 #: build/C/man2/wait.2:235
10012 msgid "B<WIFCONTINUED(>I<status>B<)>"
10015 #. type: Plain text
10016 #: build/C/man2/wait.2:240
10018 "(since Linux 2.6.10) returns true if the child process was resumed by "
10019 "delivery of B<SIGCONT>."
10023 #: build/C/man2/wait.2:240
10028 #. type: Plain text
10029 #: build/C/man2/wait.2:245
10031 "The B<waitid>() system call (available since Linux 2.6.9) provides more "
10032 "precise control over which child state changes to wait for."
10035 #. type: Plain text
10036 #: build/C/man2/wait.2:251
10038 "The I<idtype> and I<id> arguments select the child(ren) to wait for, as "
10043 #: build/C/man2/wait.2:251
10045 msgid "I<idtype> == B<P_PID>"
10048 #. type: Plain text
10049 #: build/C/man2/wait.2:254
10050 msgid "Wait for the child whose process ID matches I<id>."
10054 #: build/C/man2/wait.2:254
10056 msgid "I<idtype> == B<P_PGID>"
10059 #. type: Plain text
10060 #: build/C/man2/wait.2:257
10061 msgid "Wait for any child whose process group ID matches I<id>."
10065 #: build/C/man2/wait.2:257
10067 msgid "I<idtype> == B<P_ALL>"
10070 #. type: Plain text
10071 #: build/C/man2/wait.2:261
10072 msgid "Wait for any child; I<id> is ignored."
10075 #. type: Plain text
10076 #: build/C/man2/wait.2:265
10078 "The child state changes to wait for are specified by ORing one or more of "
10079 "the following flags in I<options>:"
10083 #: build/C/man2/wait.2:265
10088 #. type: Plain text
10089 #: build/C/man2/wait.2:268
10090 msgid "Wait for children that have terminated."
10094 #: build/C/man2/wait.2:268
10096 msgid "B<WSTOPPED>"
10099 #. type: Plain text
10100 #: build/C/man2/wait.2:271
10101 msgid "Wait for children that have been stopped by delivery of a signal."
10105 #: build/C/man2/wait.2:271
10107 msgid "B<WCONTINUED>"
10110 #. type: Plain text
10111 #: build/C/man2/wait.2:276
10113 "Wait for (previously stopped) children that have been resumed by delivery of "
10117 #. type: Plain text
10118 #: build/C/man2/wait.2:279
10119 msgid "The following flags may additionally be ORed in I<options>:"
10122 #. type: Plain text
10123 #: build/C/man2/wait.2:283
10124 msgid "As for B<waitpid>()."
10128 #: build/C/man2/wait.2:283
10133 #. type: Plain text
10134 #: build/C/man2/wait.2:287
10136 "Leave the child in a waitable state; a later wait call can be used to again "
10137 "retrieve the child status information."
10140 #. type: Plain text
10141 #: build/C/man2/wait.2:294
10143 "Upon successful return, B<waitid>() fills in the following fields of the "
10144 "I<siginfo_t> structure pointed to by I<infop>:"
10147 #. type: Plain text
10148 #: build/C/man2/wait.2:297
10149 msgid "The process ID of the child."
10152 #. type: Plain text
10153 #: build/C/man2/wait.2:301
10155 "The real user ID of the child. (This field is not set on most other "
10156 "implementations.)"
10159 #. type: Plain text
10160 #: build/C/man2/wait.2:305
10161 msgid "Always set to B<SIGCHLD>."
10165 #: build/C/man2/wait.2:305
10167 msgid "I<si_status>"
10170 #. type: Plain text
10171 #: build/C/man2/wait.2:315
10173 "Either the exit status of the child, as given to B<_exit>(2) (or "
10174 "B<exit>(3)), or the signal that caused the child to terminate, stop, or "
10175 "continue. The I<si_code> field can be used to determine how to interpret "
10179 #. type: Plain text
10180 #: build/C/man2/wait.2:332
10182 "Set to one of: B<CLD_EXITED> (child called B<_exit>(2)); B<CLD_KILLED> "
10183 "(child killed by signal); B<CLD_DUMPED> (child killed by signal, and dumped "
10184 "core); B<CLD_STOPPED> (child stopped by signal); B<CLD_TRAPPED> (traced "
10185 "child has trapped); or B<CLD_CONTINUED> (child continued by B<SIGCONT>)."
10188 #. POSIX.1-2001 leaves this possibility unspecified; most
10189 #. implementations (including Linux) zero out the structure
10190 #. in this case, but at least one implementation (AIX 5.1)
10191 #. does not -- MTK Nov 04
10192 #. type: Plain text
10193 #: build/C/man2/wait.2:354
10195 "If B<WNOHANG> was specified in I<options> and there were no children in a "
10196 "waitable state, then B<waitid>() returns 0 immediately and the state of the "
10197 "I<siginfo_t> structure pointed to by I<infop> is unspecified. To "
10198 "distinguish this case from that where a child was in a waitable state, zero "
10199 "out the I<si_pid> field before the call and check for a nonzero value in "
10200 "this field after the call returns."
10203 #. type: Plain text
10204 #: build/C/man2/wait.2:358
10206 "B<wait>(): on success, returns the process ID of the terminated child; on "
10207 "error, -1 is returned."
10210 #. type: Plain text
10211 #: build/C/man2/wait.2:367
10213 "B<waitpid>(): on success, returns the process ID of the child whose state "
10214 "has changed; if B<WNOHANG> was specified and one or more child(ren) "
10215 "specified by I<pid> exist, but have not yet changed state, then 0 is "
10216 "returned. On error, -1 is returned."
10219 #. FIXME: As reported by Vegard Nossum, if infop is NULL, then waitid()
10220 #. returns the PID of the child. Either this is a bug, or it is intended
10221 #. behavior that needs to be documented. See my Jan 2009 LKML mail
10222 #. "waitid() return value strangeness when infop is NULL".
10223 #. type: Plain text
10224 #: build/C/man2/wait.2:383
10226 "B<waitid>(): returns 0 on success or if B<WNOHANG> was specified and no "
10227 "child(ren) specified by I<id> has yet changed state; on error, -1 is "
10228 "returned. Each of these calls sets I<errno> to an appropriate value in the "
10229 "case of an error."
10233 #: build/C/man2/wait.2:384 build/C/man2/wait.2:389
10238 #. type: Plain text
10239 #: build/C/man2/wait.2:389
10241 "(for B<wait>()) The calling process does not have any unwaited-for "
10245 #. type: Plain text
10246 #: build/C/man2/wait.2:409
10248 "(for B<waitpid>() or B<waitid>()) The process specified by I<pid> "
10249 "(B<waitpid>()) or I<idtype> and I<id> (B<waitid>()) does not exist or is "
10250 "not a child of the calling process. (This can happen for one's own child if "
10251 "the action for B<SIGCHLD> is set to B<SIG_IGN>. See also the I<Linux Notes> "
10252 "section about threads.)"
10255 #. type: Plain text
10256 #: build/C/man2/wait.2:416
10258 "B<WNOHANG> was not set and an unblocked signal or a B<SIGCHLD> was caught; "
10259 "see B<signal>(7)."
10262 #. type: Plain text
10263 #: build/C/man2/wait.2:421
10264 msgid "The I<options> argument was invalid."
10267 #. type: Plain text
10268 #: build/C/man2/wait.2:436
10270 "A child that terminates, but has not been waited for becomes a \"zombie\". "
10271 "The kernel maintains a minimal set of information about the zombie process "
10272 "(PID, termination status, resource usage information) in order to allow the "
10273 "parent to later perform a wait to obtain information about the child. As "
10274 "long as a zombie is not removed from the system via a wait, it will consume "
10275 "a slot in the kernel process table, and if this table fills, it will not be "
10276 "possible to create further processes. If a parent process terminates, then "
10277 "its \"zombie\" children (if any) are adopted by B<init>(8), which "
10278 "automatically performs a wait to remove the zombies."
10281 #. type: Plain text
10282 #: build/C/man2/wait.2:477
10284 "POSIX.1-2001 specifies that if the disposition of B<SIGCHLD> is set to "
10285 "B<SIG_IGN> or the B<SA_NOCLDWAIT> flag is set for B<SIGCHLD> (see "
10286 "B<sigaction>(2)), then children that terminate do not become zombies and a "
10287 "call to B<wait>() or B<waitpid>() will block until all children have "
10288 "terminated, and then fail with I<errno> set to B<ECHILD>. (The original "
10289 "POSIX standard left the behavior of setting B<SIGCHLD> to B<SIG_IGN> "
10290 "unspecified. Note that even though the default disposition of B<SIGCHLD> is "
10291 "\"ignore\", explicitly setting the disposition to B<SIG_IGN> results in "
10292 "different treatment of zombie process children.) Linux 2.6 conforms to this "
10293 "specification. However, Linux 2.4 (and earlier) does not: if a B<wait>() "
10294 "or B<waitpid>() call is made while B<SIGCHLD> is being ignored, the call "
10295 "behaves just as though B<SIGCHLD> were not being ignored, that is, the call "
10296 "blocks until the next child terminates and then returns the process ID and "
10297 "status of that child."
10300 #. type: Plain text
10301 #: build/C/man2/wait.2:493
10303 "In the Linux kernel, a kernel-scheduled thread is not a distinct construct "
10304 "from a process. Instead, a thread is simply a process that is created using "
10305 "the Linux-unique B<clone>(2) system call; other routines such as the "
10306 "portable B<pthread_create>(3) call are implemented using B<clone>(2). "
10307 "Before Linux 2.4, a thread was just a special case of a process, and as a "
10308 "consequence one thread could not wait on the children of another thread, "
10309 "even when the latter belongs to the same thread group. However, POSIX "
10310 "prescribes such functionality, and since Linux 2.4 a thread can, and by "
10311 "default will, wait on children of other threads in the same thread group."
10314 #. type: Plain text
10315 #: build/C/man2/wait.2:500
10317 "The following Linux-specific I<options> are for use with children created "
10318 "using B<clone>(2); they cannot be used with B<waitid>():"
10322 #: build/C/man2/wait.2:500
10324 msgid "B<__WCLONE>"
10328 #. type: Plain text
10329 #: build/C/man2/wait.2:511
10331 "Wait for \"clone\" children only. If omitted then wait for \"non-clone\" "
10332 "children only. (A \"clone\" child is one which delivers no signal, or a "
10333 "signal other than B<SIGCHLD> to its parent upon termination.) This option "
10334 "is ignored if B<__WALL> is also specified."
10338 #: build/C/man2/wait.2:511
10340 msgid "B<__WALL> (since Linux 2.4)"
10343 #. since patch-2.3.48
10344 #. type: Plain text
10345 #: build/C/man2/wait.2:516
10346 msgid "Wait for all children, regardless of type (\"clone\" or \"non-clone\")."
10350 #: build/C/man2/wait.2:516
10352 msgid "B<__WNOTHREAD> (since Linux 2.4)"
10355 #. since patch-2.4.0-test8
10356 #. type: Plain text
10357 #: build/C/man2/wait.2:522
10359 "Do not wait for children of other threads in the same thread group. This "
10360 "was the default before Linux 2.4."
10363 #. fork.2 refers to this example program.
10364 #. type: Plain text
10365 #: build/C/man2/wait.2:539
10367 "The following program demonstrates the use of B<fork>(2) and B<waitpid>(). "
10368 "The program creates a child process. If no command-line argument is "
10369 "supplied to the program, then the child suspends its execution using "
10370 "B<pause>(2), to allow the user to send signals to the child. Otherwise, if "
10371 "a command-line argument is supplied, then the child exits immediately, using "
10372 "the integer supplied on the command line as the exit status. The parent "
10373 "process executes a loop that monitors the child using B<waitpid>(), and uses "
10374 "the W*() macros described above to analyze the wait status value."
10377 #. type: Plain text
10378 #: build/C/man2/wait.2:555
10382 "Child PID is 32360\n"
10384 "$B< kill -STOP 32360>\n"
10385 "stopped by signal 19\n"
10386 "$B< kill -CONT 32360>\n"
10388 "$B< kill -TERM 32360>\n"
10389 "killed by signal 15\n"
10390 "[1]+ Done ./a.out\n"
10394 #. type: Plain text
10395 #: build/C/man2/wait.2:564
10398 "#include E<lt>sys/wait.hE<gt>\n"
10399 "#include E<lt>stdlib.hE<gt>\n"
10400 "#include E<lt>unistd.hE<gt>\n"
10401 "#include E<lt>stdio.hE<gt>\n"
10404 #. type: Plain text
10405 #: build/C/man2/wait.2:570
10409 "main(int argc, char *argv[])\n"
10411 " pid_t cpid, w;\n"
10415 #. type: Plain text
10416 #: build/C/man2/wait.2:576
10419 " cpid = fork();\n"
10420 " if (cpid == -1) {\n"
10421 " perror(\"fork\");\n"
10422 " exit(EXIT_FAILURE);\n"
10426 #. type: Plain text
10427 #: build/C/man2/wait.2:582
10430 " if (cpid == 0) { /* Code executed by child */\n"
10431 " printf(\"Child PID is %ld\\en\", (long) getpid());\n"
10432 " if (argc == 1)\n"
10433 " pause(); /* Wait for signals */\n"
10434 " _exit(atoi(argv[1]));\n"
10437 #. type: Plain text
10438 #: build/C/man2/wait.2:590
10441 " } else { /* Code executed by parent */\n"
10443 " w = waitpid(cpid, &status, WUNTRACED | WCONTINUED);\n"
10444 " if (w == -1) {\n"
10445 " perror(\"waitpid\");\n"
10446 " exit(EXIT_FAILURE);\n"
10450 #. type: Plain text
10451 #: build/C/man2/wait.2:604
10454 " if (WIFEXITED(status)) {\n"
10455 " printf(\"exited, status=%d\\en\", WEXITSTATUS(status));\n"
10456 " } else if (WIFSIGNALED(status)) {\n"
10457 " printf(\"killed by signal %d\\en\", WTERMSIG(status));\n"
10458 " } else if (WIFSTOPPED(status)) {\n"
10459 " printf(\"stopped by signal %d\\en\", WSTOPSIG(status));\n"
10460 " } else if (WIFCONTINUED(status)) {\n"
10461 " printf(\"continued\\en\");\n"
10463 " } while (!WIFEXITED(status) && !WIFSIGNALED(status));\n"
10464 " exit(EXIT_SUCCESS);\n"
10469 #. type: Plain text
10470 #: build/C/man2/wait.2:616
10472 "B<_exit>(2), B<clone>(2), B<fork>(2), B<kill>(2), B<ptrace>(2), "
10473 "B<sigaction>(2), B<signal>(2), B<wait4>(2), B<pthread_create>(3), "
10474 "B<credentials>(7), B<signal>(7)"
10478 #: build/C/man2/wait4.2:34
10483 #. type: Plain text
10484 #: build/C/man2/wait4.2:37
10485 msgid "wait3, wait4 - wait for process to change state, BSD style"
10488 #. type: Plain text
10489 #: build/C/man2/wait4.2:43
10492 "B<#include E<lt>sys/types.hE<gt>>\n"
10493 "B<#include E<lt>sys/time.hE<gt>>\n"
10494 "B<#include E<lt>sys/resource.hE<gt>>\n"
10495 "B<#include E<lt>sys/wait.hE<gt>>\n"
10498 #. type: Plain text
10499 #: build/C/man2/wait4.2:46
10502 "B<pid_t wait3(int *>I<status>B<, int >I<options>B<,>\n"
10503 "B< struct rusage *>I<rusage>B<);>\n"
10506 #. type: Plain text
10507 #: build/C/man2/wait4.2:49
10510 "B<pid_t wait4(pid_t >I<pid>B<, int *>I<status>B<, int >I<options>B<,>\n"
10511 "B< struct rusage *>I<rusage>B<);>\n"
10514 #. type: Plain text
10515 #: build/C/man2/wait4.2:58
10516 msgid "B<wait3>():"
10519 #. type: Plain text
10520 #: build/C/man2/wait4.2:64
10521 msgid "B<wait4>():"
10524 #. type: Plain text
10525 #: build/C/man2/wait4.2:66
10526 msgid "_BSD_SOURCE"
10529 #. type: Plain text
10530 #: build/C/man2/wait4.2:78
10532 "The B<wait3>() and B<wait4>() system calls are similar to B<waitpid>(2), "
10533 "but additionally return resource usage information about the child in the "
10534 "structure pointed to by I<rusage>."
10537 #. type: Plain text
10538 #: build/C/man2/wait4.2:84
10540 "Other than the use of the I<rusage> argument, the following B<wait3>() "
10544 #. type: Plain text
10545 #: build/C/man2/wait4.2:87
10547 msgid " wait3(status, options, rusage);\n"
10550 #. type: Plain text
10551 #: build/C/man2/wait4.2:90 build/C/man2/wait4.2:104
10552 msgid "is equivalent to:"
10555 #. type: Plain text
10556 #: build/C/man2/wait4.2:93
10558 msgid " waitpid(-1, status, options);\n"
10561 #. type: Plain text
10562 #: build/C/man2/wait4.2:98
10563 msgid "Similarly, the following B<wait4>() call:"
10566 #. type: Plain text
10567 #: build/C/man2/wait4.2:101
10569 msgid " wait4(pid, status, options, rusage);\n"
10572 #. type: Plain text
10573 #: build/C/man2/wait4.2:107
10575 msgid " waitpid(pid, status, options);\n"
10578 #. type: Plain text
10579 #: build/C/man2/wait4.2:117
10581 "In other words, B<wait3>() waits of any child, while B<wait4>() can be "
10582 "used to select a specific child, or children, on which to wait. See "
10583 "B<wait>(2) for further details."
10586 #. type: Plain text
10587 #: build/C/man2/wait4.2:127
10589 "If I<rusage> is not NULL, the I<struct rusage> to which it points will be "
10590 "filled with accounting information about the child. See B<getrusage>(2) "
10594 #. type: Plain text
10595 #: build/C/man2/wait4.2:130 build/C/man2/wait4.2:133
10596 msgid "As for B<waitpid>(2)."
10599 #. type: Plain text
10600 #: build/C/man2/wait4.2:135
10604 #. type: Plain text
10605 #: build/C/man2/wait4.2:147
10607 "Including I<E<lt>sys/time.hE<gt>> is not required these days, but increases "
10608 "portability. (Indeed, I<E<lt>sys/resource.hE<gt>> defines the I<rusage> "
10609 "structure with fields of type I<struct timeval> defined in "
10610 "I<E<lt>sys/time.hE<gt>>.)"
10613 #. type: Plain text
10614 #: build/C/man2/wait4.2:153
10616 "On Linux, B<wait3>() is a library function implemented on top of the "
10617 "B<wait4>() system call."
10620 #. type: Plain text
10621 #: build/C/man2/wait4.2:159
10623 "B<fork>(2), B<getrusage>(2), B<sigaction>(2), B<signal>(2), B<wait>(2), "