mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-09 04:11:27 +08:00
82 lines
2.7 KiB
C
82 lines
2.7 KiB
C
/* Copyright (C) 2002, 2003, 2004 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 <errno.h>
|
|
#include <shlib-compat.h>
|
|
#include "pthreadP.h"
|
|
|
|
|
|
int
|
|
__pthread_cond_destroy (cond)
|
|
pthread_cond_t *cond;
|
|
{
|
|
/* Make sure we are alone. */
|
|
lll_mutex_lock (cond->__data.__lock);
|
|
|
|
if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
|
|
{
|
|
/* If there are still some waiters which have not been
|
|
woken up, this is an application bug. */
|
|
lll_mutex_unlock (cond->__data.__lock);
|
|
return EBUSY;
|
|
}
|
|
|
|
/* Tell pthread_cond_*wait that this condvar is being destroyed. */
|
|
cond->__data.__total_seq = -1ULL;
|
|
|
|
/* If there are waiters which have been already signalled or
|
|
broadcasted, but still are using the pthread_cond_t structure,
|
|
pthread_cond_destroy needs to wait for them. */
|
|
unsigned int nwaiters = cond->__data.__nwaiters;
|
|
|
|
if (nwaiters >= (1 << COND_CLOCK_BITS))
|
|
{
|
|
/* Wake everybody on the associated mutex in case there are
|
|
threads that have been requeued to it.
|
|
Without this, pthread_cond_destroy could block potentially
|
|
for a long time or forever, as it would depend on other
|
|
thread's using the mutex.
|
|
When all threads waiting on the mutex are woken up, pthread_cond_wait
|
|
only waits for threads to acquire and release the internal
|
|
condvar lock. */
|
|
if (cond->__data.__mutex != NULL
|
|
&& cond->__data.__mutex != (void *) ~0l)
|
|
{
|
|
pthread_mutex_t *mut = (pthread_mutex_t *) cond->__data.__mutex;
|
|
lll_futex_wake (&mut->__data.__lock, INT_MAX);
|
|
}
|
|
|
|
do
|
|
{
|
|
lll_mutex_unlock (cond->__data.__lock);
|
|
|
|
lll_futex_wait (&cond->__data.__nwaiters, nwaiters);
|
|
|
|
lll_mutex_lock (cond->__data.__lock);
|
|
|
|
nwaiters = cond->__data.__nwaiters;
|
|
}
|
|
while (nwaiters >= (1 << COND_CLOCK_BITS));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
versioned_symbol (libpthread, __pthread_cond_destroy,
|
|
pthread_cond_destroy, GLIBC_2_3_2);
|