mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-23 19:30:10 +00:00
51 lines
1.6 KiB
C
51 lines
1.6 KiB
C
/* sem_trywait -- wait on a semaphore. Generic futex-using version.
|
|
Copyright (C) 2003 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
|
|
|
|
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 <errno.h>
|
|
#include <sysdep.h>
|
|
#include <lowlevellock.h>
|
|
#include <internaltypes.h>
|
|
#include <semaphore.h>
|
|
|
|
#include <shlib-compat.h>
|
|
|
|
|
|
int
|
|
__new_sem_trywait (sem_t *sem)
|
|
{
|
|
int *futex = (int *) sem;
|
|
int val;
|
|
|
|
if (*futex > 0)
|
|
{
|
|
val = atomic_decrement_if_positive (futex);
|
|
if (val > 0)
|
|
return 0;
|
|
}
|
|
|
|
__set_errno (EAGAIN);
|
|
return -1;
|
|
}
|
|
versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1);
|
|
#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)
|
|
strong_alias (__new_sem_trywait, __old_sem_trywait)
|
|
compat_symbol (libpthread, __old_sem_trywait, sem_trywait, GLIBC_2_0);
|
|
#endif
|