mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-09 23:00:07 +00:00
64 lines
1.9 KiB
C
64 lines
1.9 KiB
C
|
/* Copyright (C) 2003 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, write to the Free
|
||
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
||
|
|
02111-1307 USA. */
|
||
|
|
|
||
|
|
#include <endian.h>
|
||
|
|
#include <errno.h>
|
||
|
|
#include <sysdep.h>
|
||
|
|
#include <lowlevellock.h>
|
||
|
|
#include <pthread.h>
|
||
|
|
#include <pthreadP.h>
|
||
|
|
|
||
|
|
#include <shlib-compat.h>
|
||
|
|
|
||
|
|
int
|
||
|
|
__pthread_cond_signal (cond)
|
||
|
|
pthread_cond_t *cond;
|
||
|
|
{
|
||
|
|
/* Make sure we are alone. */
|
||
|
|
lll_mutex_lock(cond->__data.__lock);
|
||
|
|
|
||
|
|
/* 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;
|
||
|
|
|
||
|
|
/* The futex syscall operates on a 32-bit word. That is fine,
|
||
|
|
we just use the low 32 bits of the sequence counter. */
|
||
|
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
||
|
|
int *futex = ((int *) (&cond->__data.__wakeup_seq));
|
||
|
|
#elif BYTE_ORDER == BIG_ENDIAN
|
||
|
|
int *futex = ((int *) (&cond->__data.__wakeup_seq)) + 1;
|
||
|
|
#else
|
||
|
|
# error "No valid byte order"
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* Wake one. */
|
||
|
|
lll_futex_wake (futex, 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* We are done. */
|
||
|
|
lll_mutex_unlock (cond->__data.__lock);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
|
||
|
|
GLIBC_2_3_2);
|