uclibc-ng/libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_wait.S

/* Copyright (C) 2002-2004,2006-2007,2009,2010 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, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <lowlevellock.h>
#include <lowlevelcond.h>
#include <tcb-offsets.h>
#include <pthread-errnos.h>
#include <pthread-pi-defines.h>
#include <bits/kernel-features.h>


	.text

/* int pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex)  */
	.globl	__pthread_cond_wait
	.type	__pthread_cond_wait, @function
	.protected	__pthread_cond_wait
	.align	16
__pthread_cond_wait:
.LSTARTCODE:
	cfi_startproc
#ifdef SHARED
	cfi_personality(DW_EH_PE_pcrel | DW_EH_PE_sdata4 | DW_EH_PE_indirect,
			DW.ref.__gcc_personality_v0)
	cfi_lsda(DW_EH_PE_pcrel | DW_EH_PE_sdata4, .LexceptSTART)
#else
	cfi_personality(DW_EH_PE_udata4, __gcc_personality_v0)
	cfi_lsda(DW_EH_PE_udata4, .LexceptSTART)
#endif

	pushl	%ebp
	cfi_adjust_cfa_offset(4)
	cfi_rel_offset(%ebp, 0)
	pushl	%edi
	cfi_adjust_cfa_offset(4)
	cfi_rel_offset(%edi, 0)
	pushl	%esi
	cfi_adjust_cfa_offset(4)
	cfi_rel_offset(%esi, 0)
	pushl	%ebx
	cfi_adjust_cfa_offset(4)
	cfi_rel_offset(%ebx, 0)

	xorl	%esi, %esi
	movl	20(%esp), %ebx

	/* Get internal lock.  */
	movl	$1, %edx
	xorl	%eax, %eax
	LOCK
#if cond_lock == 0
	cmpxchgl %edx, (%ebx)
#else
	cmpxchgl %edx, cond_lock(%ebx)
#endif
	jnz	1f

	/* Store the reference to the mutex.  If there is already a
	   different value in there this is a bad user bug.  */
2:	cmpl	$-1, dep_mutex(%ebx)
	movl	24(%esp), %eax
	je	15f
	movl	%eax, dep_mutex(%ebx)

	/* Unlock the mutex.  */
15:	xorl	%edx, %edx
	call	__pthread_mutex_unlock_usercnt

	testl	%eax, %eax
	jne	12f

	addl	$1, total_seq(%ebx)
	adcl	$0, total_seq+4(%ebx)
	addl	$1, cond_futex(%ebx)
	addl	$(1 << nwaiters_shift), cond_nwaiters(%ebx)

#define FRAME_SIZE 20
	subl	$FRAME_SIZE, %esp
	cfi_adjust_cfa_offset(FRAME_SIZE)
	cfi_remember_state

	/* Get and store current wakeup_seq value.  */
	movl	wakeup_seq(%ebx), %edi
	movl	wakeup_seq+4(%ebx), %edx
	movl	broadcast_seq(%ebx), %eax
	movl	%edi, 4(%esp)
	movl	%edx, 8(%esp)
	movl	%eax, 12(%esp)

	/* Reset the pi-requeued flag.  */
8:	movl	$0, 16(%esp)
	movl	cond_futex(%ebx), %ebp

	/* Unlock.  */
	LOCK
#if cond_lock == 0
	subl	$1, (%ebx)
#else
	subl	$1, cond_lock(%ebx)
#endif
	jne	3f

.LcleanupSTART:
4:	call	__pthread_enable_asynccancel
	movl	%eax, (%esp)

	xorl	%ecx, %ecx
	cmpl	$-1, dep_mutex(%ebx)
	sete	%cl
	je	18f

	movl	dep_mutex(%ebx), %edi
	/* Requeue to a non-robust PI mutex if the PI bit is set and
	   the robust bit is not set.  */
	movl	MUTEX_KIND(%edi), %eax
	andl	$(ROBUST_BIT|PI_BIT), %eax
	cmpl	$PI_BIT, %eax
	jne	18f

	movl	$(FUTEX_WAIT_REQUEUE_PI|FUTEX_PRIVATE_FLAG), %ecx
	movl	%ebp, %edx
	xorl	%esi, %esi
	addl	$cond_futex, %ebx
	movl	$SYS_futex, %eax
	ENTER_KERNEL
	subl	$cond_futex, %ebx
	/* Set the pi-requeued flag only if the kernel has returned 0. The
	   kernel does not hold the mutex on error.  */
	cmpl	$0, %eax
	sete	16(%esp)
	je	19f

	/* Normal and PI futexes dont mix. Use normal futex functions only
	   if the kernel does not support the PI futex functions.  */
	cmpl	$-ENOSYS, %eax
	jne	19f
	xorl	%ecx, %ecx

18:	subl	$1, %ecx
#ifdef __ASSUME_PRIVATE_FUTEX
	andl	$FUTEX_PRIVATE_FLAG, %ecx
#else
	andl	%gs:PRIVATE_FUTEX, %ecx
#endif
#if FUTEX_WAIT != 0
	addl	$FUTEX_WAIT, %ecx
#endif
	movl	%ebp, %edx
	addl	$cond_futex, %ebx
.Ladd_cond_futex:
	movl	$SYS_futex, %eax
	ENTER_KERNEL
	subl	$cond_futex, %ebx
.Lsub_cond_futex:

19:	movl	(%esp), %eax
	call	__pthread_disable_asynccancel
.LcleanupEND:

	/* Lock.  */
	movl	$1, %edx
	xorl	%eax, %eax
	LOCK
#if cond_lock == 0
	cmpxchgl %edx, (%ebx)
#else
	cmpxchgl %edx, cond_lock(%ebx)
#endif
	jnz	5f

6:	movl	broadcast_seq(%ebx), %eax
	cmpl	12(%esp), %eax
	jne	16f

	movl	woken_seq(%ebx), %eax
	movl	woken_seq+4(%ebx), %ecx

	movl	wakeup_seq(%ebx), %edi
	movl	wakeup_seq+4(%ebx), %edx

	cmpl	8(%esp), %edx
	jne	7f
	cmpl	4(%esp), %edi
	je	8b

7:	cmpl	%ecx, %edx
	jne	9f
	cmp	%eax, %edi
	je	8b

9:	addl	$1, woken_seq(%ebx)
	adcl	$0, woken_seq+4(%ebx)

	/* Unlock */
16:	subl	$(1 << nwaiters_shift), cond_nwaiters(%ebx)

	/* Wake up a thread which wants to destroy the condvar object.  */
	movl	total_seq(%ebx), %eax
	andl	total_seq+4(%ebx), %eax
	cmpl	$0xffffffff, %eax
	jne	17f
	movl	cond_nwaiters(%ebx), %eax
	andl	$~((1 << nwaiters_shift) - 1), %eax
	jne	17f

	addl	$cond_nwaiters, %ebx
	movl	$SYS_futex, %eax
#if FUTEX_PRIVATE_FLAG > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex-cond_nwaiters(%ebx)
	sete	%cl
	subl	$1, %ecx
#ifdef __ASSUME_PRIVATE_FUTEX
	andl	$FUTEX_PRIVATE_FLAG, %ecx
#else
	andl	%gs:PRIVATE_FUTEX, %ecx
#endif
	addl	$FUTEX_WAKE, %ecx
	movl	$1, %edx
	ENTER_KERNEL
	subl	$cond_nwaiters, %ebx

17:	LOCK
#if cond_lock == 0
	subl	$1, (%ebx)
#else
	subl	$1, cond_lock(%ebx)
#endif
	jne	10f

	/* With requeue_pi, the mutex lock is held in the kernel.  */
11:	movl	24+FRAME_SIZE(%esp), %eax
	movl	16(%esp), %ecx
	testl	%ecx, %ecx
	jnz	21f

	call	__pthread_mutex_cond_lock
20:	addl	$FRAME_SIZE, %esp
	cfi_adjust_cfa_offset(-FRAME_SIZE);

14:	popl	%ebx
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%ebx)
	popl	%esi
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%esi)
	popl	%edi
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%edi)
	popl	%ebp
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%ebp)

	/* We return the result of the mutex_lock operation.  */
	ret

	cfi_restore_state

21:	call	__pthread_mutex_cond_lock_adjust
	xorl	%eax, %eax
	jmp	20b

	cfi_adjust_cfa_offset(-FRAME_SIZE);
	/* Initial locking failed.  */
1:
#if cond_lock == 0
	movl	%ebx, %edx
#else
	leal	cond_lock(%ebx), %edx
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex(%ebx)
	setne	%cl
	subl	$1, %ecx
	andl	$(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
	addl	$LLL_PRIVATE, %ecx
#endif
	call	__lll_lock_wait
	jmp	2b

	/* The initial unlocking of the mutex failed.  */
12:
	LOCK
#if cond_lock == 0
	subl	$1, (%ebx)
#else
	subl	$1, cond_lock(%ebx)
#endif
	jne	14b

	movl	%eax, %esi
#if cond_lock == 0
	movl	%ebx, %eax
#else
	leal	cond_lock(%ebx), %eax
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex(%ebx)
	setne	%cl
	subl	$1, %ecx
	andl	$(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
	addl	$LLL_PRIVATE, %ecx
#endif
	call	__lll_unlock_wake

	movl	%esi, %eax
	jmp	14b

	cfi_adjust_cfa_offset(FRAME_SIZE)

	/* Unlock in loop requires wakeup.  */
3:
#if cond_lock == 0
	movl	%ebx, %eax
#else
	leal	cond_lock(%ebx), %eax
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex(%ebx)
	setne	%cl
	subl	$1, %ecx
	andl	$(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
	addl	$LLL_PRIVATE, %ecx
#endif
	call	__lll_unlock_wake
	jmp	4b

	/* Locking in loop failed.  */
5:
#if cond_lock == 0
	movl	%ebx, %edx
#else
	leal	cond_lock(%ebx), %edx
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex(%ebx)
	setne	%cl
	subl	$1, %ecx
	andl	$(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
	addl	$LLL_PRIVATE, %ecx
#endif
	call	__lll_lock_wait
	jmp	6b

	/* Unlock after loop requires wakeup.  */
10:
#if cond_lock == 0
	movl	%ebx, %eax
#else
	leal	cond_lock(%ebx), %eax
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex(%ebx)
	setne	%cl
	subl	$1, %ecx
	andl	$(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
	addl	$LLL_PRIVATE, %ecx
#endif
	call	__lll_unlock_wake
	jmp	11b
	.size	__pthread_cond_wait, .-__pthread_cond_wait
weak_alias(__pthread_cond_wait, pthread_cond_wait)


	.type	__condvar_w_cleanup2, @function
__condvar_w_cleanup2:
	subl	$cond_futex, %ebx
	.size	__condvar_w_cleanup2, .-__condvar_w_cleanup2
.LSbl4:
	.type	__condvar_w_cleanup, @function
__condvar_w_cleanup:
	movl	%eax, %esi

	/* Get internal lock.  */
	movl	$1, %edx
	xorl	%eax, %eax
	LOCK
#if cond_lock == 0
	cmpxchgl %edx, (%ebx)
#else
	cmpxchgl %edx, cond_lock(%ebx)
#endif
	jz	1f

#if cond_lock == 0
	movl	%ebx, %edx
#else
	leal	cond_lock(%ebx), %edx
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex(%ebx)
	setne	%cl
	subl	$1, %ecx
	andl	$(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
	addl	$LLL_PRIVATE, %ecx
#endif
	call	__lll_lock_wait

1:	movl	broadcast_seq(%ebx), %eax
	cmpl	12(%esp), %eax
	jne	3f

	/* We increment the wakeup_seq counter only if it is lower than
	   total_seq.  If this is not the case the thread was woken and
	   then canceled.  In this case we ignore the signal.  */
	movl	total_seq(%ebx), %eax
	movl	total_seq+4(%ebx), %edi
	cmpl	wakeup_seq+4(%ebx), %edi
	jb	6f
	ja	7f
	cmpl	wakeup_seq(%ebx), %eax
	jbe	7f

6:	addl	$1, wakeup_seq(%ebx)
	adcl	$0, wakeup_seq+4(%ebx)
	addl	$1, cond_futex(%ebx)

7:	addl	$1, woken_seq(%ebx)
	adcl	$0, woken_seq+4(%ebx)

3:	subl	$(1 << nwaiters_shift), cond_nwaiters(%ebx)

	/* Wake up a thread which wants to destroy the condvar object.  */
	xorl	%edi, %edi
	movl	total_seq(%ebx), %eax
	andl	total_seq+4(%ebx), %eax
	cmpl	$0xffffffff, %eax
	jne	4f
	movl	cond_nwaiters(%ebx), %eax
	andl	$~((1 << nwaiters_shift) - 1), %eax
	jne	4f

	addl	$cond_nwaiters, %ebx
	movl	$SYS_futex, %eax
#if FUTEX_PRIVATE_FLAG > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex-cond_nwaiters(%ebx)
	sete	%cl
	subl	$1, %ecx
#ifdef __ASSUME_PRIVATE_FUTEX
	andl	$FUTEX_PRIVATE_FLAG, %ecx
#else
	andl	%gs:PRIVATE_FUTEX, %ecx
#endif
	addl	$FUTEX_WAKE, %ecx
	movl	$1, %edx
	ENTER_KERNEL
	subl	$cond_nwaiters, %ebx
	movl	$1, %edi

4:	LOCK
#if cond_lock == 0
	subl	$1, (%ebx)
#else
	subl	$1, cond_lock(%ebx)
#endif
	je	2f

#if cond_lock == 0
	movl	%ebx, %eax
#else
	leal	cond_lock(%ebx), %eax
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex(%ebx)
	setne	%cl
	subl	$1, %ecx
	andl	$(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
	addl	$LLL_PRIVATE, %ecx
#endif
	call	__lll_unlock_wake

	/* Wake up all waiters to make sure no signal gets lost.  */
2:	testl	%edi, %edi
	jnz	5f
	addl	$cond_futex, %ebx
#if FUTEX_PRIVATE_FLAG > 255
	xorl	%ecx, %ecx
#endif
	cmpl	$-1, dep_mutex-cond_futex(%ebx)
	sete	%cl
	subl	$1, %ecx
#ifdef __ASSUME_PRIVATE_FUTEX
	andl	$FUTEX_PRIVATE_FLAG, %ecx
#else
	andl	%gs:PRIVATE_FUTEX, %ecx
#endif
	addl	$FUTEX_WAKE, %ecx
	movl	$SYS_futex, %eax
	movl	$0x7fffffff, %edx
	ENTER_KERNEL

5:	movl	24+FRAME_SIZE(%esp), %eax
	call	__pthread_mutex_cond_lock

	movl	%esi, (%esp)
.LcallUR:
#ifdef __PIC__
	call	__i686.get_pc_thunk.bx
	addl	$_GLOBAL_OFFSET_TABLE_, %ebx
#endif
	call	_Unwind_Resume@PLT
	hlt
.LENDCODE:
	cfi_endproc
	.size	__condvar_w_cleanup, .-__condvar_w_cleanup


	.section .gcc_except_table,"a",@progbits
.LexceptSTART:
	.byte	DW_EH_PE_omit			# @LPStart format (omit)
	.byte	DW_EH_PE_omit			# @TType format (omit)
	.byte	DW_EH_PE_sdata4			# call-site format
						# DW_EH_PE_sdata4
	.uleb128 .Lcstend-.Lcstbegin
.Lcstbegin:
	.long	.LcleanupSTART-.LSTARTCODE
	.long	.Ladd_cond_futex-.LcleanupSTART
	.long	__condvar_w_cleanup-.LSTARTCODE
	.uleb128  0
	.long	.Ladd_cond_futex-.LSTARTCODE
	.long	.Lsub_cond_futex-.Ladd_cond_futex
	.long	__condvar_w_cleanup2-.LSTARTCODE
	.uleb128  0
	.long	.Lsub_cond_futex-.LSTARTCODE
	.long	.LcleanupEND-.Lsub_cond_futex
	.long	__condvar_w_cleanup-.LSTARTCODE
	.uleb128  0
	.long	.LcallUR-.LSTARTCODE
	.long	.LENDCODE-.LcallUR
	.long	0
	.uleb128  0
.Lcstend:

#ifdef __PIC__
	.section .gnu.linkonce.t.__i686.get_pc_thunk.bx,"ax",@progbits
	.globl	__i686.get_pc_thunk.bx
	.hidden	__i686.get_pc_thunk.bx
	.type	__i686.get_pc_thunk.bx,@function
__i686.get_pc_thunk.bx:
	movl (%esp), %ebx;
	ret
	.size	__i686.get_pc_thunk.bx,.-__i686.get_pc_thunk.bx
#endif

#ifdef SHARED
	.hidden DW.ref.__gcc_personality_v0
	.weak   DW.ref.__gcc_personality_v0
	.section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits
	.align 4
	.type   DW.ref.__gcc_personality_v0, @object
	.size   DW.ref.__gcc_personality_v0, 4
DW.ref.__gcc_personality_v0:
	.long   __gcc_personality_v0
#endif