mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 21:40:12 +00:00
9410140c5e
2004-12-29 Roland McGrath <roland@redhat.com> [BZ #626] * sysdeps/unix/alarm.c (alarm): Round return value to nearest rather than always up; when nearest is zero, round up to one.
52 lines
2.0 KiB
C
52 lines
2.0 KiB
C
/* Copyright (C) 1991,1992,1994,1997,2002,2004 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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <unistd.h>
|
|
#include <sys/time.h>
|
|
|
|
/* Schedule an alarm. In SECONDS seconds, the process will get a SIGALRM.
|
|
If SECONDS is zero, any currently scheduled alarm will be cancelled.
|
|
The function returns the number of seconds remaining until the last
|
|
alarm scheduled would have signaled, or zero if there wasn't one.
|
|
There is no return value to indicate an error, but you can set `errno'
|
|
to 0 and check its value after calling `alarm', and this might tell you.
|
|
The signal may come late due to processor scheduling. */
|
|
unsigned int
|
|
alarm (seconds)
|
|
unsigned int seconds;
|
|
{
|
|
struct itimerval old, new;
|
|
unsigned int retval;
|
|
|
|
new.it_interval.tv_usec = 0;
|
|
new.it_interval.tv_sec = 0;
|
|
new.it_value.tv_usec = 0;
|
|
new.it_value.tv_sec = (long int) seconds;
|
|
if (__setitimer (ITIMER_REAL, &new, &old) < 0)
|
|
return 0;
|
|
|
|
retval = old.it_value.tv_sec;
|
|
/* Round to the nearest second, but never report zero seconds when
|
|
the alarm is still set. */
|
|
if (old.it_value.tv_usec >= 500000
|
|
|| (retval == 0 && old.it_value.tv_usec > 0))
|
|
++retval;
|
|
return retval;
|
|
}
|
|
libc_hidden_def (alarm)
|