7a1147946e
2003-06-15 Ulrich Drepper <drepper@redhat.com> Fix cancellation point handling wrt exception based cleanup. * io/Makefile: Compile fcntl.c, poll.c, and lockf.c with exceptions. * misc/Makefile: Compile pselect.c, readv.c, writev.c, and usleep.c with exceptions. * posix/Makefile: Compile pread.c, pread64.c, pwrite.c, pwrite64.c, sleep.c, wait.c, waitid.c, and waitpid.c with exceptions. * rt/Makefile: Compile aio_suspend.c and clock_nanosleep.c with exceptions. * signal/Makefile: Compile sigpause.c, sigsuspend.c, sigtimedwait.c, sigwait.c, and sigwaitinfo.c with exceptions. * stdlib/Makefile: Compile system.c with exceptions. * sysvipc/Makefile: Compile msgrcv.c and msgsnd.c with exceptions. * termios/Makefile: Compile tcdrain.c with exceptions. * sysdeps/generic/lockf.c: Add comment explaining the cancellation situation. * sysdeps/generic/pselect.c: Likewise. * sysdeps/posix/sigpause.c: Likewise. * sysdeps/posix/system.c: Likewise. * sysdeps/posix/waitid.c: Likewise. * sysdeps/unix/sysv/linux/sleep.c: Likewise. * sysdeps/unix/sysv/linux/usleep.c: Likewise. * sysdeps/unix/sysv/linux/i386/sysdep.h: Major rewrite of INTERNAL_SYSCALL to not use push inside asm statement so that unwind info is correct around the syscall. * sysdeps/unix/clock_nanosleep.c: Add cancellation support. * sysdeps/unix/sysv/linux/clock_nanosleep.c: Likewise.
97 lines
3.2 KiB
C
97 lines
3.2 KiB
C
/* Implementation of the POSIX sleep function using nanosleep.
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Copyright (C) 1996, 1997, 1998, 1999, 2003 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <errno.h>
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#include <time.h>
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#include <signal.h>
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#include <unistd.h>
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/* We are going to use the `nanosleep' syscall of the kernel. But the
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kernel does not implement the sstupid SysV SIGCHLD vs. SIG_IGN
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behaviour for this syscall. Therefore we have to emulate it here. */
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unsigned int
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__sleep (unsigned int seconds)
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{
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struct timespec ts = { .tv_sec = (long int) seconds, .tv_nsec = 0 };
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sigset_t set, oset;
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unsigned int result;
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/* This is not necessary but some buggy programs depend on this. */
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if (seconds == 0)
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return 0;
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/* Linux will wake up the system call, nanosleep, when SIGCHLD
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arrives even if SIGCHLD is ignored. We have to deal with it
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in libc. We block SIGCHLD first. */
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if (__sigemptyset (&set) < 0
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|| __sigaddset (&set, SIGCHLD) < 0
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|| __sigprocmask (SIG_BLOCK, &set, &oset))
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return -1;
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/* If SIGCHLD is already blocked, we don't have to do anything. */
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if (!__sigismember (&oset, SIGCHLD))
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{
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int saved_errno;
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struct sigaction oact;
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if (__sigemptyset (&set) < 0 || __sigaddset (&set, SIGCHLD) < 0)
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return -1;
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/* We get the signal handler for SIGCHLD. */
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if (__sigaction (SIGCHLD, (struct sigaction *) NULL, &oact) < 0)
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{
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saved_errno = errno;
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/* Restore the original signal mask. */
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(void) __sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
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__set_errno (saved_errno);
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return -1;
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}
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/* Note the sleep() is a cancellation point. But since we call
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nanosleep() which itself is a cancellation point we do not
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have to do anything here. */
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if (oact.sa_handler == SIG_IGN)
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{
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/* We should leave SIGCHLD blocked. */
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result = __nanosleep (&ts, &ts);
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saved_errno = errno;
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/* Restore the original signal mask. */
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(void) __sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
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__set_errno (saved_errno);
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}
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else
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{
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/* We should unblock SIGCHLD. Restore the original signal mask. */
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(void) __sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
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result = __nanosleep (&ts, &ts);
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}
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}
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else
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result = __nanosleep (&ts, &ts);
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if (result != 0)
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/* Round remaining time. */
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result = (unsigned int) ts.tv_sec + (ts.tv_nsec >= 500000000L);
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return result;
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}
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weak_alias (__sleep, sleep)
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