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/* Copyright (C) 2002-2015 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 <shlib-compat.h>
#include <lowlevellock.h>
#include <lowlevelcond.h>
#include <kernel-features.h>
#include <pthread-pi-defines.h>
#include <pthread-errnos.h>
#include <stap-probe.h>
.text
/* int pthread_cond_signal (pthread_cond_t *cond) */
.globl __pthread_cond_signal
.type __pthread_cond_signal, @function
.align 16
__pthread_cond_signal:
cfi_startproc
pushl %ebx
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%ebx, 0)
pushl %edi
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%edi, 0)
cfi_remember_state
movl 12(%esp), %edi
LIBC_PROBE (cond_signal, 1, %edi)
/* Get internal lock. */
movl $1, %edx
xorl %eax, %eax
LOCK
#if cond_lock == 0
cmpxchgl %edx, (%edi)
#else
cmpxchgl %edx, cond_lock(%edi)
#endif
jnz 1f
2: leal cond_futex(%edi), %ebx
movl total_seq+4(%edi), %eax
movl total_seq(%edi), %ecx
cmpl wakeup_seq+4(%edi), %eax
#if cond_lock != 0
/* Must use leal to preserve the flags. */
leal cond_lock(%edi), %edi
#endif
ja 3f
jb 4f
cmpl wakeup_seq-cond_futex(%ebx), %ecx
jbe 4f
/* Bump the wakeup number. */
3: addl $1, wakeup_seq-cond_futex(%ebx)
adcl $0, wakeup_seq-cond_futex+4(%ebx)
addl $1, (%ebx)
/* Wake up one thread. */
pushl %esi
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%esi, 0)
pushl %ebp
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%ebp, 0)
#if FUTEX_PRIVATE_FLAG > 255
xorl %ecx, %ecx
#endif
cmpl $-1, dep_mutex-cond_futex(%ebx)
sete %cl
je 8f
movl dep_mutex-cond_futex(%ebx), %edx
/* Requeue to a non-robust PI mutex if the PI bit is set and
the robust bit is not set. */
movl MUTEX_KIND(%edx), %eax
andl $(ROBUST_BIT|PI_BIT), %eax
cmpl $PI_BIT, %eax
je 9f
8: subl $1, %ecx
#ifdef __ASSUME_PRIVATE_FUTEX
andl $FUTEX_PRIVATE_FLAG, %ecx
#else
andl %gs:PRIVATE_FUTEX, %ecx
#endif
addl $FUTEX_WAKE_OP, %ecx
movl $SYS_futex, %eax
movl $1, %edx
movl $1, %esi
movl $FUTEX_OP_CLEAR_WAKE_IF_GT_ONE, %ebp
/* FIXME: Until Ingo fixes 4G/4G vDSO, 6 arg syscalls are broken for
sysenter.
ENTER_KERNEL */
int $0x80
popl %ebp
cfi_adjust_cfa_offset(-4)
cfi_restore(%ebp)
popl %esi
cfi_adjust_cfa_offset(-4)
cfi_restore(%esi)
/* For any kind of error, we try again with WAKE.
The general test also covers running on old kernels. */
cmpl $-4095, %eax
jae 7f
6: xorl %eax, %eax
popl %edi
cfi_adjust_cfa_offset(-4)
cfi_restore(%edi)
popl %ebx
cfi_adjust_cfa_offset(-4)
cfi_restore(%ebx)
ret
cfi_restore_state
9: movl $(FUTEX_CMP_REQUEUE_PI|FUTEX_PRIVATE_FLAG), %ecx
movl $SYS_futex, %eax
movl $1, %edx
xorl %esi, %esi
movl dep_mutex-cond_futex(%ebx), %edi
movl (%ebx), %ebp
/* FIXME: Until Ingo fixes 4G/4G vDSO, 6 arg syscalls are broken for
sysenter.
ENTER_KERNEL */
int $0x80
popl %ebp
popl %esi
leal -cond_futex(%ebx), %edi
/* For any kind of error, we try again with WAKE.
The general test also covers running on old kernels. */
cmpl $-4095, %eax
jb 4f
7:
#ifdef __ASSUME_PRIVATE_FUTEX
andl $FUTEX_PRIVATE_FLAG, %ecx
#else
andl %gs:PRIVATE_FUTEX, %ecx
#endif
orl $FUTEX_WAKE, %ecx
movl $SYS_futex, %eax
/* %edx should be 1 already from $FUTEX_WAKE_OP syscall.
movl $1, %edx */
ENTER_KERNEL
/* Unlock. Note that at this point %edi always points to
cond_lock. */
4: LOCK
subl $1, (%edi)
je 6b
/* Unlock in loop requires wakeup. */
5: movl %edi, %eax
#if (LLL_SHARED-LLL_PRIVATE) > 255
xorl %ecx, %ecx
#endif
cmpl $-1, dep_mutex-cond_futex(%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 6b
/* Initial locking failed. */
1:
#if cond_lock == 0
movl %edi, %edx
#else
leal cond_lock(%edi), %edx
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
xorl %ecx, %ecx
#endif
cmpl $-1, dep_mutex(%edi)
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
cfi_endproc
.size __pthread_cond_signal, .-__pthread_cond_signal
versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
GLIBC_2_3_2)
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