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/* Lock a semaphore if it does not require blocking. Generic version.
Copyright (C) 2005-2018 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 <semaphore.h>
#include <errno.h>
#include <pt-internal.h>
int
__sem_trywait (sem_t *sem)
{
__pthread_spin_lock (&sem->__lock);
if (sem->__value > 0)
/* Successful down. */
{
sem->__value--;
__pthread_spin_unlock (&sem->__lock);
return 0;
}
__pthread_spin_unlock (&sem->__lock);
errno = EAGAIN;
return -1;
}
strong_alias (__sem_trywait, sem_trywait);
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