2003-03-10 Ulrich Drepper <drepper@redhat.com>
+ * sysdeps/unix/sysv/linux/x86_64/pthread_barrier_wait.S: New file
+
* sysdeps/unix/sysv/linux/Makefile (gen-as-const-headers): Add
lowlevelbarrier.sym.
* sysdeps/unix/sysv/linux/lowlevelbarrier.sym: New file.
* sysdeps/unix/sysv/linux/i386/i486/pthread_barrier_wait.S:
Include lowlevelbarrier.h and don't define offsets locally.
+ * sysdeps/unix/sysv/linux/sh/pthread_barrier_wait.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
(__lll_mutex_lock_wait): Reverse order of first two parameters.
--- /dev/null
+/* 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 <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 16
+pthread_barrier_wait:
+ /* Get the mutex. */
+ orl $-1, %esi
+ LOCK
+ xaddl %esi, MUTEX(%rdi)
+ jne 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
+ addl $1, MUTEX(%rdi)
+ jng 6f
+
+ /* Wait for the remaining threads. The call will return immediately
+ if the CURR_EVENT memory has meanwhile been changed. */
+7: xorq %rsi, %rsi /* movl $FUTEX_WAIT, %ecx */
+ xorq %r10, %r10
+8: movq $SYS_futex, %rax
+ 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
+
+ /* Note: %esi is still zero. */
+ movl %esi, %eax /* != PTHREAD_BARRIER_SERIAL_THREAD */
+
+ retq
+
+ /* The necessary number of threads arrived. */
+3: movl INIT_COUNT(%rdi), %eax
+ movl %eax, LEFT(%rdi)
+#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
+ movq $FUTEX_WAKE, %rsi
+ movq $SYS_futex, %rax
+ syscall
+
+ /* 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
+ addl $1, MUTEX(%rdi)
+ jng 4f
+
+5: orl $-1, %eax /* == PTHREAD_BARRIER_SERIAL_THREAD */
+
+ retq
+
+1: addq $MUTEX, %rdi
+ call __lll_lock_wait
+ subq $MUTEX, %rdi
+ jmp 2b
+
+4: addq $MUTEX, %rdi
+ call __lll_unlock_wake
+ subq $MUTEX, %rdi
+ jmp 5b
+
+6: addq $MUTEX, %rdi
+ call __lll_unlock_wake
+ subq $MUTEX, %rdi
+ jmp 7b
+ .size pthread_barrier_wait,.-pthread_barrier_wait
projects / thirdparty / glibc.git / commitdiff
