mirror of
git://sourceware.org/git/glibc.git
synced 2024-11-21 01:12:26 +08:00
68 lines
2.1 KiB
C
68 lines
2.1 KiB
C
/* Copyright (C) 2003-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Martin Schwidefsky <schwidefsky@de.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, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <sysdep.h>
|
|
#include <lowlevellock.h>
|
|
#include <pthread.h>
|
|
#include <pthreadP.h>
|
|
#include <stap-probe.h>
|
|
#include <elide.h>
|
|
|
|
|
|
/* Unlock RWLOCK. */
|
|
int
|
|
__pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
|
|
{
|
|
LIBC_PROBE (rwlock_unlock, 1, rwlock);
|
|
|
|
if (ELIDE_UNLOCK (rwlock->__data.__writer == 0
|
|
&& rwlock->__data.__nr_readers == 0))
|
|
return 0;
|
|
|
|
lll_lock (rwlock->__data.__lock, rwlock->__data.__shared);
|
|
if (rwlock->__data.__writer)
|
|
rwlock->__data.__writer = 0;
|
|
else
|
|
--rwlock->__data.__nr_readers;
|
|
if (rwlock->__data.__nr_readers == 0)
|
|
{
|
|
if (rwlock->__data.__nr_writers_queued)
|
|
{
|
|
++rwlock->__data.__writer_wakeup;
|
|
lll_unlock (rwlock->__data.__lock, rwlock->__data.__shared);
|
|
lll_futex_wake (&rwlock->__data.__writer_wakeup, 1,
|
|
rwlock->__data.__shared);
|
|
return 0;
|
|
}
|
|
else if (rwlock->__data.__nr_readers_queued)
|
|
{
|
|
++rwlock->__data.__readers_wakeup;
|
|
lll_unlock (rwlock->__data.__lock, rwlock->__data.__shared);
|
|
lll_futex_wake (&rwlock->__data.__readers_wakeup, INT_MAX,
|
|
rwlock->__data.__shared);
|
|
return 0;
|
|
}
|
|
}
|
|
lll_unlock (rwlock->__data.__lock, rwlock->__data.__shared);
|
|
return 0;
|
|
}
|
|
|
|
weak_alias (__pthread_rwlock_unlock, pthread_rwlock_unlock)
|
|
hidden_def (__pthread_rwlock_unlock)
|