1 /* Implementation of the POSIX sleep function using nanosleep.
2 Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
27 /* This is a quick and dirty, but not 100% compliant with
28 * the stupid SysV SIGCHLD vs. SIG_IGN behaviour. It is
29 * fine unless you are messing with SIGCHLD... */
30 unsigned int sleep (unsigned int sec)
32 struct timespec ts = {
33 tv_sec: (long int) sec,
37 return(sec-ts.tv_sec);
42 /* We are going to use the `nanosleep' syscall of the kernel. But the
43 kernel does not implement the sstupid SysV SIGCHLD vs. SIG_IGN
44 behaviour for this syscall. Therefore we have to emulate it here. */
45 unsigned int sleep (unsigned int seconds)
47 struct timespec ts = { tv_sec: (long int) seconds, tv_nsec: 0 };
51 /* This is not necessary but some buggy programs depend on this. */
55 /* Linux will wake up the system call, nanosleep, when SIGCHLD
56 arrives even if SIGCHLD is ignored. We have to deal with it
57 in libc. We block SIGCHLD first. */
58 if (__sigemptyset (&set) < 0
59 || __sigaddset (&set, SIGCHLD) < 0
60 || sigprocmask (SIG_BLOCK, &set, &oset))
63 /* If SIGCHLD is already blocked, we don't have to do anything. */
64 if (!__sigismember (&oset, SIGCHLD))
67 struct sigaction oact;
69 if (__sigemptyset (&set) < 0 || __sigaddset (&set, SIGCHLD) < 0)
72 /* We get the signal handler for SIGCHLD. */
73 if (sigaction (SIGCHLD, (struct sigaction *) NULL, &oact) < 0)
76 /* Restore the original signal mask. */
77 (void) sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
78 __set_errno (saved_errno);
82 if (oact.sa_handler == SIG_IGN)
84 /* We should leave SIGCHLD blocked. */
85 result = nanosleep (&ts, &ts);
88 /* Restore the original signal mask. */
89 (void) sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
90 __set_errno (saved_errno);
94 /* We should unblock SIGCHLD. Restore the original signal mask. */
95 (void) sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
96 result = nanosleep (&ts, &ts);
100 result = nanosleep (&ts, &ts);
103 /* Round remaining time. */
104 result = (unsigned int) ts.tv_sec + (ts.tv_nsec >= 500000000L);