mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-19 01:11:05 +00:00
85 lines
2.5 KiB
C
85 lines
2.5 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 <endian.h>
|
|
#include <errno.h>
|
|
#include <sysdep.h>
|
|
#include <lowlevellock.h>
|
|
#include <pthread.h>
|
|
#include <pthreadP.h>
|
|
|
|
#include <shlib-compat.h>
|
|
#include <kernel-features.h>
|
|
#include <stap-probe.h>
|
|
|
|
|
|
int
|
|
__pthread_cond_signal (cond)
|
|
pthread_cond_t *cond;
|
|
{
|
|
int pshared = (cond->__data.__mutex == (void *) ~0l)
|
|
? LLL_SHARED : LLL_PRIVATE;
|
|
|
|
LIBC_PROBE (cond_signal, 1, cond);
|
|
|
|
/* Make sure we are alone. */
|
|
lll_lock (cond->__data.__lock, pshared);
|
|
|
|
/* Are there any waiters to be woken? */
|
|
if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
|
|
{
|
|
/* Yes. Mark one of them as woken. */
|
|
++cond->__data.__wakeup_seq;
|
|
++cond->__data.__futex;
|
|
|
|
#if (defined lll_futex_cmp_requeue_pi \
|
|
&& defined __ASSUME_REQUEUE_PI)
|
|
pthread_mutex_t *mut = cond->__data.__mutex;
|
|
|
|
if (USE_REQUEUE_PI (mut)
|
|
/* This can only really fail with a ENOSYS, since nobody can modify
|
|
futex while we have the cond_lock. */
|
|
&& lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, 0,
|
|
&mut->__data.__lock,
|
|
cond->__data.__futex, pshared) == 0)
|
|
{
|
|
lll_unlock (cond->__data.__lock, pshared);
|
|
return 0;
|
|
}
|
|
else
|
|
#endif
|
|
/* Wake one. */
|
|
if (! __builtin_expect (lll_futex_wake_unlock (&cond->__data.__futex,
|
|
1, 1,
|
|
&cond->__data.__lock,
|
|
pshared), 0))
|
|
return 0;
|
|
|
|
/* Fallback if neither of them work. */
|
|
lll_futex_wake (&cond->__data.__futex, 1, pshared);
|
|
}
|
|
|
|
/* We are done. */
|
|
lll_unlock (cond->__data.__lock, pshared);
|
|
|
|
return 0;
|
|
}
|
|
|
|
versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
|
|
GLIBC_2_3_2);
|