pthread_cond_wait implementation for Linux/x86-64.

This commit is contained in:
Ulrich Drepper 2003-03-11 10:36:15 +00:00
parent b33e61633a
commit 0bc91edf8e

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@ -0,0 +1,265 @@
/* Copyright (C) 2002, 2003 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 <shlib-compat.h>
#include <lowlevelcond.h>
#include <tcb-offsets.h>
#ifdef UP
# define LOCK
#else
# define LOCK lock
#endif
#define SYS_futex 202
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
.text
.align 16
.type __condvar_cleanup, @function
.globl __condvar_cleanup
.hidden __condvar_cleanup
__condvar_cleanup:
/* Get internal lock. */
movq %rdi, %r8
movl 8(%rdi), %rdi
movl $1, %esi
LOCK
#if cond_lock == 0
xaddl %esi, (%rdi)
#else
xaddl %esi, cond_lock(%rdi)
#endif
testl %esi, %esi
je 1f
#if cond_lock != 0
addq $cond_lock, %rdi
#endif
callq __lll_mutex_lock_wait
#if cond_lock != 0
subq $cond_lock, %rdi
#endif
1: addq $1, wakeup_seq(%rdi)
addq $1, woken_seq(%rdi)
LOCK
#if cond_lock == 0
decl (%rdi)
#else
decl cond_lock(%rdi)
#endif
je 2f
#if cond_lock != 0
addq $cond_lock, %rdi
#endif
callq __lll_mutex_unlock_wake
/* Lock the mutex unless asynchronous cancellation is in effect. */
2: testq $2, (%r8)
jne 3f
movq 16(%r8), %edi
callq __pthread_mutex_lock_internal
3: retq
.size __condvar_cleanup, .-__condvar_cleanup
/* int pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex) */
.globl __pthread_cond_wait
.type __pthread_cond_wait, @function
.align 16
__pthread_cond_wait:
pushq %12
subq $64, %rsp
/* Prepare structure passed to cancellation handler. */
movq %rdi, 8(%rsp)
movq %rsi, 16(%rsp)
/* Get internal lock. */
movl $1, %esi
LOCK
#if cond_lock == 0
xaddl %esi, (%rdi)
#else
xaddl %esi, cond_lock(%rdi)
#endif
testl %esi, %esi
jne 1f
/* Unlock the mutex. */
2: movq 16(%rsp), %rdi
callq __pthread_mutex_unlock_internal
testl %eax, %eax
jne 12f
movq (%rsp), %rdi
addq $1, total_seq(%rdi)
/* Install cancellation handler. */
#ifdef PIC
leaq __condvar_cleanup@GOTOFF(%rip), %rsi
#else
leaq __condvar_cleanup, %rsi
#endif
leaq 32(%rsp), %rdi
movq %rsp, %rdx
callq __pthread_cleanup_push
/* Get and store current wakeup_seq value. */
movq 8(%rsp), %rdi
movq wakeup_seq(%rdi), %r12
movq %r12, 24(%rsp)
/* Unlock. */
8: LOCK
#if cond_lock == 0
decl (%rdi)
#else
decl cond_lock(%rdi)
#endif
jne 3f
4: callq __pthread_enable_asynccancel
movq %rax, (%rsp)
xorq %r10, %r10
movq %r12, %rdx
addq $wakeup_seq-cond_lock, %rdi
movq $SYS_futex, %rax
movq %r10, %rsi /* movl $FUTEX_WAIT, %ecx */
syscall
subl $wakeup_seq-cond_lock, %ebx
movq (%rsp), %rdi
callq __pthread_disable_asynccancel
/* Lock. */
movq 8(%rsp), %rdi
movl $1, %esi
LOCK
#if cond_lock == 0
xaddl %esi, (%rdi)
#else
xaddl %esi, cond_lock(%rdi)
#endif
testl %esi, %esi
jne 5f
6: movq woken_seq(%rdi), %rax
movq wakeup_seq(%rdi), %r12
cmpq 24(%rsp), %rax
jb 8b
cmpq %rax, %r12
jna 8b
incq woken_seq(%rdi)
LOCK
#if cond_lock == 0
decl (%rdi)
#else
decl cond_lock(%rdi)
#endif
jne 10f
/* Remove cancellation handler. */
11: movq 32+CLEANUP_PREV(%rsp), %rdx
movq %rdx, %gs:CLEANUP
movq 16(%rsp), %rdi
callq __pthread_mutex_lock_internal
14: addq $64, %rsp
popq %r12
/* We return the result of the mutex_lock operation. */
retq
/* Initial locking failed. */
1:
#if cond_lock != 0
addq $cond_lock, %rdi
#endif
callq __lll_mutex_lock_wait
jmp 2b
/* Unlock in loop requires waekup. */
3:
#if cond_lock != 0
addq $cond_lock, %rdi
#endif
callq __lll_mutex_unlock_wake
#if cond_lock != 0
subq $cond_lock, %rdi
#endif
jmp 4b
/* Locking in loop failed. */
5:
#if cond_lock != 0
addq $cond_lock, %rdi
#endif
call __lll_mutex_lock_wait
#if cond_lock != 0
subq $cond_lock, %rdi
#endif
jmp 6b
/* Unlock after loop requires wakeup. */
10:
#if cond_lock != 0
addq $cond_lock, %rdi
#endif
callq __lll_mutex_unlock_wake
jmp 11b
/* The initial unlocking of the mutex failed. */
12: movq %rax, %r10
movq 8(%rsp), %rdi
LOCK
#if cond_lock == 0
decl (%rdi)
#else
decl cond_lock(%rdi)
#endif
jne 13f
#if cond_lock != 0
addq $cond_lock, %rdi
#endif
callq __lll_mutex_unlock_wake
13: movq %r10, %rax
jmp 14b
.size __pthread_cond_wait, .-__pthread_cond_wait
versioned_symbol (libpthread, __pthread_cond_wait, pthread_cond_wait,
GLIBC_2_3_2)