glibc/sysdeps/unix/sysv/linux/arm/nptl/pthread_once.c
Daniel Jacobowitz 713ddf8d12 * sysdeps/arm/nptl/tls.h (THREAD_GSCOPE_RESET_FLAG): Use
lll_futex_wake not lll_private_futex_wake.
	* sysdeps/unix/sysv/linux/arm/bits/fcntl.h (O_CLOEXEC): Define.
	* sysdeps/unix/sysv/linux/arm/eabi/sysdep.h: Include <tls.h>
	* sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.c
	(__lll_lock_wait_private, __lll_lock_wait): New.
	(__lll_timedlock_wait): Don't include in libc.so;  Take private
	argument.  Use atomic_compare_and_exchange_bool_acq.
	* sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h: Renamed all
	lll_mutex_* resp. lll_robust_mutex_* macros to lll_*
	resp. lll_robust_*.  Renamed all LLL_MUTEX_LOCK_* macros to
	LLL_LOCK_*.  Include <kernel-features.h>.
	(LLL_LOCK_INITIALIZER): Remove duplicate definition.
	(__lll_private_flag): Define.
	(lll_futex_timed_wait): Pass private flag to syscall.
	(lll_futex_wake): Likewise.
	(lll_private_futex_wait, lll_private_futex_timed_wait,
	lll_private_futex_wake): Remove.
	(lll_robust_dead, lll_futex_requeue): Take private arguments.
	(lll_futex_wake_unlock): Pass private flag to syscall.
	(__lll_robust_trylock): Convert to macro.
	(__lll_robust_lock_wait): Add private argument.
	(__lll_lock_wait_private, __lll_lock_wait): Declare.
	(__lll_lock): Convert to macro.  Take private argument.
	(__lll_cond_lock): Likewise.
	(lll_lock, lll_cond_lock): Take private arguments.
	(__lll_robust_lock): Take private argument.
	(__lll_timedlock_wait, __lll_robust_timedlock_wait): Take private
	arguments.
	(__lll_timedlock, __lll_robust_timedlock): Convert to macros.
	Take private arguments.
	(lll_timedlock, lll_robust_timedlock): Take private arguments.
	(__lll_unlock, __lll_robust_unlock): Convert to macros.  Take
	private arguments.
	(lll_unlock, lll_robust_unlock): Take private arguments.
	(__lll_mutex_unlock_force, lll_mutex_unlock_force, lll_lock_t,
	lll_trylock, lll_lock, lll_unlock, lll_islocked): Remove.
	(lll_wait_tid): Pass LLL_SHARED to lll_futex_wait.
	(__lll_cond_wait, __lll_cond_timedwait, __lll_cond_wake,
	__lll_cond_broadcast, lll_cond_wait, lll_cond_timedwait,
	lll_cond_wake, lll_cond_broadcast): Remove.
	* sysdeps/unix/sysv/linux/arm/nptl/pthread_once.c
	(clear_once_control, __pthread_once): Use lll_futex_wake not
	lll_private_futex_wake.
2007-09-12 12:57:25 +00:00

100 lines
3.1 KiB
C

/* Copyright (C) 2004, 2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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>
unsigned long int __fork_generation attribute_hidden;
static void
clear_once_control (void *arg)
{
pthread_once_t *once_control = (pthread_once_t *) arg;
*once_control = 0;
lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
}
int
__pthread_once (pthread_once_t *once_control, void (*init_routine) (void))
{
for (;;)
{
int oldval;
int newval;
/* Pseudo code:
newval = __fork_generation | 1;
oldval = *once_control;
if ((oldval & 2) == 0)
*once_control = newval;
Do this atomically.
*/
do
{
newval = __fork_generation | 1;
oldval = *once_control;
if (oldval & 2)
break;
} while (atomic_compare_and_exchange_val_acq (once_control, newval, oldval) != oldval);
/* Check if the initializer has already been done. */
if ((oldval & 2) != 0)
return 0;
/* Check if another thread already runs the initializer. */
if ((oldval & 1) == 0)
break;
/* Check whether the initializer execution was interrupted by a fork. */
if (oldval != newval)
break;
/* Same generation, some other thread was faster. Wait. */
lll_futex_wait (once_control, oldval, LLL_PRIVATE);
}
/* This thread is the first here. Do the initialization.
Register a cleanup handler so that in case the thread gets
interrupted the initialization can be restarted. */
pthread_cleanup_push (clear_once_control, once_control);
init_routine ();
pthread_cleanup_pop (0);
/* Say that the initialisation is done. */
*once_control = __fork_generation | 2;
/* Wake up all other threads. */
lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
return 0;
}
weak_alias (__pthread_once, pthread_once)
strong_alias (__pthread_once, __pthread_once_internal)
#if defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__PIC__)
/* When statically linked, if pthread_create is used, this file
will be brought in. The exception handling code in GCC assumes
that if pthread_create is available, so are these. */
const void *include_pthread_getspecific attribute_hidden = pthread_getspecific;
const void *include_pthread_setspecific attribute_hidden = pthread_setspecific;
const void *include_pthread_key_create attribute_hidden = pthread_key_create;
#endif