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/* Wait on a semaphore with a timeout. Generic version.
Copyright (C) 2005 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <semaphore.h>
#include <error.h>
#include <errno.h>
#include <assert.h>
#include <pt-internal.h>
int
__sem_timedwait_internal (sem_t *restrict sem,
const struct timespec *restrict timeout)
{
struct __pthread *self;
__pthread_spin_lock (&sem->__lock);
if (sem->__value > 0)
/* Successful down. */
{
sem->__value --;
__pthread_spin_unlock (&sem->__lock);
return 0;
}
/* Add ourselves to the queue. */
self = _pthread_self ();
__pthread_enqueue (&sem->__queue, self);
__pthread_spin_unlock (&sem->__lock);
/* Block the thread. */
if (timeout)
{
error_t err;
if (timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000)
{
errno = EINVAL;
return -1;
}
err = __pthread_timedblock (self, timeout);
if (err)
/* We timed out. We may need to disconnect ourself from the
waiter queue.
FIXME: What do we do if we get a wakeup message before we
disconnect ourself? It may remain until the next time we
block. */
{
assert (err == ETIMEDOUT);
__pthread_spin_lock (&sem->__lock);
if (self->prevp)
__pthread_dequeue (self);
__pthread_spin_unlock (&sem->__lock);
errno = err;
return -1;
}
}
else
__pthread_block (self);
return 0;
}
int
__sem_timedwait (sem_t *restrict sem,
const struct timespec *restrict timeout)
{
return __sem_timedwait_internal (sem, timeout);
}
weak_alias (__sem_timedwait, sem_timedwait);
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