/* Copyright (C) 2002, 2003, 2004, 2005 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 <sysdep.h>#include <lowlevelbarrier.h>#define SYS_futex	202#define FUTEX_WAIT	0#define FUTEX_WAKE	1#ifndef UP# define LOCK lock#else# define LOCK#endif	.text	.globl	pthread_barrier_wait	.type	pthread_barrier_wait,@function	.align	16pthread_barrier_wait:	/* Get the mutex.  */	xorl	%eax, %eax	movl	$1, %esi	LOCK	cmpxchgl %esi, MUTEX(%rdi)	jnz	1f	/* One less waiter.  If this was the last one needed wake	   everybody.  */2:	decl	LEFT(%rdi)	je	3f	/* There are more threads to come.  */#if CURR_EVENT == 0	movl	(%rdi), %edx#else	movl	CURR_EVENT(%rdi), %edx#endif	/* Release the mutex.  */	LOCK	decl	MUTEX(%rdi)	jne	6f	/* Wait for the remaining threads.  The call will return immediately	   if the CURR_EVENT memory has meanwhile been changed.  */7:#if FUTEX_WAIT == 0	xorl	%esi, %esi#else	movl	$FUTEX_WAIT, %esi#endif	xorq	%r10, %r108:	movl	$SYS_futex, %eax	syscall	/* Don't return on spurious wakeups.  The syscall does not change	   any register except %eax so there is no need to reload any of	   them.  */#if CURR_EVENT == 0	cmpl	%edx, (%rdi)#else	cmpl	%edx, CURR_EVENT(%rdi)#endif	je	8b	/* Increment LEFT.  If this brings the count back to the	   initial count unlock the object.  */	movl	$1, %edx	movl	INIT_COUNT(%rdi), %eax	LOCK	xaddl	%edx, LEFT(%rdi)	subl	$1, %eax	cmpl	%eax, %edx	jne,pt	10f	/* Release the mutex.  We cannot release the lock before	   waking the waiting threads since otherwise a new thread might	   arrive and gets waken up, too.  */	LOCK	decl	MUTEX(%rdi)	jne	9f10:	xorl	%eax, %eax		/* != PTHREAD_BARRIER_SERIAL_THREAD */	retq	/* The necessary number of threads arrived.  */3:#if CURR_EVENT == 0	incl	(%rdi)#else	incl	CURR_EVENT(%rdi)#endif	/* Wake up all waiters.  The count is a signed number in the kernel	   so 0x7fffffff is the highest value.  */	movl	$0x7fffffff, %edx	movl	$FUTEX_WAKE, %esi	movl	$SYS_futex, %eax	syscall	/* Increment LEFT.  If this brings the count back to the	   initial count unlock the object.  */	movl	$1, %edx	movl	INIT_COUNT(%rdi), %eax	LOCK	xaddl	%edx, LEFT(%rdi)	subl	$1, %eax	cmpl	%eax, %edx	jne,pt	5f	/* Release the mutex.  We cannot release the lock before	   waking the waiting threads since otherwise a new thread might	   arrive and gets waken up, too.  */	LOCK	decl	MUTEX(%rdi)	jne	4f5:	orl	$-1, %eax		/* == PTHREAD_BARRIER_SERIAL_THREAD */	retq1:	addq	$MUTEX, %rdi	callq	__lll_mutex_lock_wait	subq	$MUTEX, %rdi	jmp	2b4:	addq	$MUTEX, %rdi	callq	__lll_mutex_unlock_wake	jmp	5b6:	addq	$MUTEX, %rdi	callq	__lll_mutex_unlock_wake	subq	$MUTEX, %rdi	jmp	7b9:	addq	$MUTEX, %rdi	callq	__lll_mutex_unlock_wake	jmp	10b	.size	pthread_barrier_wait,.-pthread_barrier_wait