glibc/nptl/pthread_cond_wait.c
2002-12-15 19:59:08 +00:00

68 lines
2.1 KiB
C

/* Copyright (C) 2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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 "pthreadP.h"
#include <lowlevellock.h>
int
__pthread_cond_wait (cond, mutex)
pthread_cond_t *cond;
pthread_mutex_t *mutex;
{
int err;
/* This function is a cancellation point. Test before we potentially
go to sleep. */
CANCELLATION_P (THREAD_SELF);
/* Make sure the condition is modified atomically. */
lll_mutex_lock (cond->__data.__lock);
/* Release the mutex. This might fail. */
err = INTUSE(__pthread_mutex_unlock) (mutex);
if (__builtin_expect (err != 0, 0))
{
lll_mutex_unlock (cond->__data.__lock);
return err;
}
/* One more tread waiting. */
++cond->__data.__nr_sleepers;
/* The actual conditional variable implementation. */
lll_cond_wait (cond);
if (--cond->__data.__nr_sleepers == 0)
/* Forget about the current wakeups now that they are done. */
cond->__data.__nr_wakers = 0;
/* Lose the condvar lock. */
lll_mutex_unlock (cond->__data.__lock);
/* We have to get the mutex before returning. */
err = INTUSE(__pthread_mutex_lock) (mutex);
/* Cancellation handling. */
CANCELLATION_P (THREAD_SELF);
return err;
}
strong_alias (__pthread_cond_wait, pthread_cond_wait)