glibc/sysdeps/posix/sleep.c
Adhemerval Zanella 8c873bf019 Remove signal handling for nanosleep (bug 16364)
Linux 2.6.32 and forward do not show the issue regarding SysV SIGCHLD
vs. SIG_IGN for nanosleep which make it feasible to use it for sleep
implementation without requiring any hacking to handle the spurious
wake up.  The issue is likely being fixed before 2.6 and git
history [1] [2].

This patch simplifies the sleep code to call nanosleep directly by
using the posix default version.  It also removes the early cancellation
tests for zero argument, since nanosleep will handle cancellation
in this case.

[1] https://lkml.org/lkml/2004/11/25/5
[2] https://lkml.org/lkml/2003/11/8/50

Checked on x86_64, ppc64le, and aarch64.

	[BZ #16364]
	* sysdeps/unix/sysv/linux/sleep.c: Remove file
	* sysdeps/posix/sleep.c (__sleep): Simplify cancellation handling.
2015-11-20 11:16:07 -02:00

67 lines
2.3 KiB
C

/* Sleep for a given number of seconds. POSIX.1 version.
Copyright (C) 1991-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <sys/param.h>
/* Make the process sleep for SECONDS seconds, or until a signal arrives
and is not ignored. The function returns the number of seconds less
than SECONDS which it actually slept (zero if it slept the full time).
If a signal handler does a `longjmp' or modifies the handling of the
SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
signal afterwards is undefined. There is no return value to indicate
error, but if `sleep' returns SECONDS, it probably didn't work. */
unsigned int
__sleep (unsigned int seconds)
{
int save_errno = errno;
const unsigned int max
= (unsigned int) (((unsigned long int) (~((time_t) 0))) >> 1);
struct timespec ts = { 0, 0 };
do
{
if (sizeof (ts.tv_sec) <= sizeof (seconds))
{
/* Since SECONDS is unsigned assigning the value to .tv_sec can
overflow it. In this case we have to wait in steps. */
ts.tv_sec += MIN (seconds, max);
seconds -= (unsigned int) ts.tv_sec;
}
else
{
ts.tv_sec = (time_t) seconds;
seconds = 0;
}
if (__nanosleep (&ts, &ts) < 0)
/* We were interrupted.
Return the number of (whole) seconds we have not yet slept. */
return seconds + ts.tv_sec;
}
while (seconds > 0);
__set_errno (save_errno);
return 0;
}
weak_alias (__sleep, sleep)