diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S b/sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S new file mode 100644 index 0000000000..0e8fe0c0f3 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S @@ -0,0 +1,164 @@ +/* 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 <pthread-pi-defines.h> +#include <kernel-features.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: + + LIBC_PROBE (cond_signal, 1, %rdi) + + /* Get internal lock. */ + movq %rdi, %r8 + movl $1, %esi + xorl %eax, %eax + LOCK +#if cond_lock == 0 + cmpxchgl %esi, (%rdi) +#else + cmpxchgl %esi, cond_lock(%rdi) +#endif + jnz 1f + +2: addq $cond_futex, %rdi + movq total_seq(%r8), %rcx + cmpq wakeup_seq(%r8), %rcx + jbe 4f + + /* Bump the wakeup number. */ + addq $1, wakeup_seq(%r8) + addl $1, (%rdi) + + /* Wake up one thread. */ + LP_OP(cmp) $-1, dep_mutex(%r8) + movl $FUTEX_WAKE_OP, %esi + movl $1, %edx + movl $SYS_futex, %eax + je 8f + + /* Get the address of the mutex used. */ + mov dep_mutex(%r8), %RCX_LP + movl MUTEX_KIND(%rcx), %r11d + andl $(ROBUST_BIT|PI_BIT), %r11d + cmpl $PI_BIT, %r11d + je 9f + +#ifdef __ASSUME_PRIVATE_FUTEX + movl $(FUTEX_WAKE_OP|FUTEX_PRIVATE_FLAG), %esi +#else + orl %fs:PRIVATE_FUTEX, %esi +#endif + +8: movl $1, %r10d +#if cond_lock != 0 + addq $cond_lock, %r8 +#endif + movl $FUTEX_OP_CLEAR_WAKE_IF_GT_ONE, %r9d + syscall +#if cond_lock != 0 + subq $cond_lock, %r8 +#endif + /* For any kind of error, we try again with WAKE. + The general test also covers running on old kernels. */ + cmpq $-4095, %rax + jae 7f + + xorl %eax, %eax + retq + + /* Wake up one thread and requeue none in the PI Mutex case. */ +9: movl $(FUTEX_CMP_REQUEUE_PI|FUTEX_PRIVATE_FLAG), %esi + movq %rcx, %r8 + xorq %r10, %r10 + movl (%rdi), %r9d // XXX Can this be right? + syscall + + leaq -cond_futex(%rdi), %r8 + + /* For any kind of error, we try again with WAKE. + The general test also covers running on old kernels. */ + cmpq $-4095, %rax + jb 4f + +7: +#ifdef __ASSUME_PRIVATE_FUTEX + andl $FUTEX_PRIVATE_FLAG, %esi +#else + andl %fs:PRIVATE_FUTEX, %esi +#endif + orl $FUTEX_WAKE, %esi + movl $SYS_futex, %eax + /* %rdx should be 1 already from $FUTEX_WAKE_OP syscall. + movl $1, %edx */ + syscall + + /* Unlock. */ +4: LOCK +#if cond_lock == 0 + decl (%r8) +#else + decl cond_lock(%r8) +#endif + jne 5f + +6: xorl %eax, %eax + retq + + /* Initial locking failed. */ +1: +#if cond_lock != 0 + addq $cond_lock, %rdi +#endif + LP_OP(cmp) $-1, dep_mutex-cond_lock(%rdi) + movl $LLL_PRIVATE, %eax + movl $LLL_SHARED, %esi + cmovne %eax, %esi + callq __lll_lock_wait +#if cond_lock != 0 + subq $cond_lock, %rdi +#endif + jmp 2b + + /* Unlock in loop requires wakeup. */ +5: + movq %r8, %rdi +#if cond_lock != 0 + addq $cond_lock, %rdi +#endif + LP_OP(cmp) $-1, dep_mutex-cond_lock(%rdi) + movl $LLL_PRIVATE, %eax + movl $LLL_SHARED, %esi + cmovne %eax, %esi + callq __lll_unlock_wake + jmp 6b + .size __pthread_cond_signal, .-__pthread_cond_signal +versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal, + GLIBC_2_3_2) |