📄 pthread_cond_wait.s
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/* Copyright (C) 2002,2003,2004,2005,2006,2007 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 <lowlevellock.h>#include <lowlevelcond.h>#include <tcb-offsets.h>#include <kernel-features.h> .text .align 16 .type __condvar_cleanup, @function .globl __condvar_cleanup .hidden __condvar_cleanup__condvar_cleanup: pushq %r12 /* Get internal lock. */ movq %rdi, %r8 movq 8(%rdi), %rdi movl $1, %esi xorl %eax, %eax LOCK#if cond_lock == 0 cmpxchgl %esi, (%rdi)#else cmpxchgl %esi, cond_lock(%rdi)#endif jz 1f#if cond_lock != 0 addq $cond_lock, %rdi#endif cmpq $-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#endif1: movl broadcast_seq(%rdi), %edx cmpl 4(%r8), %edx 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. */ movq total_seq(%rdi), %rax cmpq wakeup_seq(%rdi), %rax jbe 6f incq wakeup_seq(%rdi) incl cond_futex(%rdi)6: incq woken_seq(%rdi)3: subl $(1 << nwaiters_shift), cond_nwaiters(%rdi) /* Wake up a thread which wants to destroy the condvar object. */ xorq %r12, %r12 cmpq $0xffffffffffffffff, total_seq(%rdi) jne 4f movl cond_nwaiters(%rdi), %eax andl $~((1 << nwaiters_shift) - 1), %eax jne 4f addq $cond_nwaiters, %rdi cmpq $-1, dep_mutex-cond_nwaiters(%rdi) movl $1, %edx#ifdef __ASSUME_PRIVATE_FUTEX movl $FUTEX_WAKE, %eax movl $(FUTEX_WAKE|FUTEX_PRIVATE_FLAG), %esi cmove %eax, %esi#else movl $0, %eax movl %fs:PRIVATE_FUTEX, %esi cmove %eax, %esi orl $FUTEX_WAKE, %esi#endif movl $SYS_futex, %eax syscall subq $cond_nwaiters, %rdi movl $1, %r12d4: LOCK#if cond_lock == 0 decl (%rdi)#else decl cond_lock(%rdi)#endif je 2f#if cond_lock != 0 addq $cond_lock, %rdi#endif cmpq $-1, dep_mutex-cond_lock(%rdi) movl $LLL_PRIVATE, %eax movl $LLL_SHARED, %esi cmovne %eax, %esi callq __lll_unlock_wake /* Wake up all waiters to make sure no signal gets lost. */2: testq %r12, %r12 jnz 5f addq $cond_futex, %rdi cmpq $-1, dep_mutex-cond_futex(%rdi) movl $0x7fffffff, %edx#ifdef __ASSUME_PRIVATE_FUTEX movl $FUTEX_WAKE, %eax movl $(FUTEX_WAKE|FUTEX_PRIVATE_FLAG), %esi cmove %eax, %esi#else movl $0, %eax movl %fs:PRIVATE_FUTEX, %esi cmove %eax, %esi orl $FUTEX_WAKE, %esi#endif movl $SYS_futex, %eax syscall5: movq 16(%r8), %rdi callq __pthread_mutex_cond_lock popq %r12 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:.LSTARTCODE: pushq %r12.Lpush_r12:#define FRAME_SIZE 64 subq $FRAME_SIZE, %rsp.Lsubq: /* Stack frame: rsp + 64 +--------------------------+ rsp + 32 | cleanup buffer | +--------------------------+ rsp + 24 | old wake_seq value | +--------------------------+ rsp + 16 | mutex pointer | +--------------------------+ rsp + 8 | condvar pointer | +--------------------------+ rsp + 4 | old broadcast_seq value | +--------------------------+ rsp + 0 | old cancellation mode | +--------------------------+ */ cmpq $-1, dep_mutex(%rdi) /* Prepare structure passed to cancellation handler. */ movq %rdi, 8(%rsp) movq %rsi, 16(%rsp) je 15f movq %rsi, dep_mutex(%rdi) /* Get internal lock. */15: movl $1, %esi xorl %eax, %eax LOCK#if cond_lock == 0 cmpxchgl %esi, (%rdi)#else cmpxchgl %esi, cond_lock(%rdi)#endif jne 1f /* Unlock the mutex. */2: movq 16(%rsp), %rdi xorl %esi, %esi callq __pthread_mutex_unlock_usercnt testl %eax, %eax jne 12f movq 8(%rsp), %rdi incq total_seq(%rdi) incl cond_futex(%rdi) addl $(1 << nwaiters_shift), cond_nwaiters(%rdi) /* Install cancellation handler. */#ifdef PIC leaq __condvar_cleanup(%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), %r9 movl broadcast_seq(%rdi), %edx movq %r9, 24(%rsp) movl %edx, 4(%rsp) /* Unlock. */8: movl cond_futex(%rdi), %r12d LOCK#if cond_lock == 0 decl (%rdi)#else decl cond_lock(%rdi)#endif jne 3f4: callq __pthread_enable_asynccancel movl %eax, (%rsp) movq 8(%rsp), %rdi xorq %r10, %r10 movq %r12, %rdx addq $cond_futex-cond_lock, %rdi cmpq $-1, dep_mutex-cond_futex(%rdi)#ifdef __ASSUME_PRIVATE_FUTEX movl $FUTEX_WAIT, %eax movl $(FUTEX_WAIT|FUTEX_PRIVATE_FLAG), %esi cmove %eax, %esi#else movl $FUTEX_WAIT, %eax movl %fs:PRIVATE_FUTEX, %esi cmove %eax, %esi# if FUTEX_WAIT != 0 orl $FUTEX_WAIT, %esi# endif#endif movl $SYS_futex, %eax syscall movl (%rsp), %edi callq __pthread_disable_asynccancel /* Lock. */ movq 8(%rsp), %rdi movl $1, %esi xorl %eax, %eax LOCK#if cond_lock == 0 cmpxchgl %esi, (%rdi)#else cmpxchgl %esi, cond_lock(%rdi)#endif jnz 5f6: movl broadcast_seq(%rdi), %edx movq woken_seq(%rdi), %rax movq wakeup_seq(%rdi), %r9 cmpl 4(%rsp), %edx jne 16f cmpq 24(%rsp), %r9 jbe 8b cmpq %rax, %r9 jna 8b incq woken_seq(%rdi) /* Unlock */16: subl $(1 << nwaiters_shift), cond_nwaiters(%rdi) /* Wake up a thread which wants to destroy the condvar object. */ cmpq $0xffffffffffffffff, total_seq(%rdi) jne 17f movl cond_nwaiters(%rdi), %eax andl $~((1 << nwaiters_shift) - 1), %eax jne 17f addq $cond_nwaiters, %rdi cmpq $-1, dep_mutex-cond_nwaiters(%rdi) movl $1, %edx#ifdef __ASSUME_PRIVATE_FUTEX movl $FUTEX_WAKE, %eax movl $(FUTEX_WAKE|FUTEX_PRIVATE_FLAG), %esi cmove %eax, %esi#else movl $0, %eax movl %fs:PRIVATE_FUTEX, %esi cmove %eax, %esi orl $FUTEX_WAKE, %esi#endif movl $SYS_futex, %eax syscall subq $cond_nwaiters, %rdi17: 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, %fs:CLEANUP movq 16(%rsp), %rdi callq __pthread_mutex_cond_lock14: addq $FRAME_SIZE, %rsp.Laddq: popq %r12.Lpop_r12: /* We return the result of the mutex_lock operation. */ retq /* Initial locking failed. */1:.LSbl1:#if cond_lock != 0 addq $cond_lock, %rdi#endif cmpq $-1, dep_mutex-cond_lock(%rdi) movl $LLL_PRIVATE, %eax movl $LLL_SHARED, %esi cmovne %eax, %esi callq __lll_lock_wait jmp 2b /* Unlock in loop requires wakeup. */3:#if cond_lock != 0 addq $cond_lock, %rdi#endif cmpq $-1, dep_mutex-cond_lock(%rdi) movl $LLL_PRIVATE, %eax movl $LLL_SHARED, %esi cmovne %eax, %esi callq __lll_unlock_wake jmp 4b /* Locking in loop failed. */5:#if cond_lock != 0 addq $cond_lock, %rdi#endif cmpq $-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 6b /* Unlock after loop requires wakeup. */10:#if cond_lock != 0 addq $cond_lock, %rdi#endif cmpq $-1, dep_mutex-cond_lock(%rdi) movl $LLL_PRIVATE, %eax movl $LLL_SHARED, %esi cmovne %eax, %esi callq __lll_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 je 13f#if cond_lock != 0 addq $cond_lock, %rdi#endif cmpq $-1, dep_mutex-cond_lock(%rdi) movl $LLL_PRIVATE, %eax movl $LLL_SHARED, %esi cmovne %eax, %esi callq __lll_unlock_wake13: movq %r10, %rax jmp 14b.LENDCODE: .size __pthread_cond_wait, .-__pthread_cond_waitversioned_symbol (libpthread, __pthread_cond_wait, pthread_cond_wait, GLIBC_2_3_2) .section .eh_frame,"a",@progbits.LSTARTFRAME: .long L(ENDCIE)-L(STARTCIE) # Length of the CIE..LSTARTCIE: .long 0 # CIE ID. .byte 1 # Version number.#ifdef SHARED .string "zR" # NUL-terminated augmentation # string.#else .ascii "\0" # NUL-terminated augmentation # string.#endif .uleb128 1 # Code alignment factor. .sleb128 -8 # Data alignment factor. .byte 16 # Return address register # column.#ifdef SHARED .uleb128 1 # Augmentation value length. .byte 0x1b # Encoding: DW_EH_PE_pcrel # + DW_EH_PE_sdata4.#endif .byte 0x0c # DW_CFA_def_cfa .uleb128 7 .uleb128 8 .byte 0x90 # DW_CFA_offset, column 0x8 .uleb128 1 .align 8.LENDCIE: .long .LENDFDE-.LSTARTFDE # Length of the FDE..LSTARTFDE: .long .LSTARTFDE-.LSTARTFRAME # CIE pointer.#ifdef SHARED .long .LSTARTCODE-. # PC-relative start address # of the code#else .long .LSTARTCODE # Start address of the code.#endif .long .LENDCODE-.LSTARTCODE # Length of the code.#ifdef SHARED .uleb128 0 # No augmentation data.#endif .byte 0x40+.Lpush_r12-.LSTARTCODE # DW_CFA_advance_loc+N .byte 14 # DW_CFA_def_cfa_offset .uleb128 16 .byte 0x8c # DW_CFA_offset %r12 .uleb128 2 .byte 0x40+.Lsubq-.Lpush_r12 # DW_CFA_advance_loc+N .byte 14 # DW_CFA_def_cfa_offset .uleb128 16+FRAME_SIZE .byte 3 # DW_CFA_advance_loc2 .2byte .Laddq-.Lsubq .byte 14 # DW_CFA_def_cfa_offset .uleb128 16 .byte 0x40+.Lpop_r12-.Laddq # DW_CFA_advance_loc+N .byte 14 # DW_CFA_def_cfa_offset .uleb128 8 .byte 0xcc # DW_CFA_restore %r12 .byte 0x40+.LSbl1-.Lpop_r12 # DW_CFA_advance_loc+N .byte 14 # DW_CFA_def_cfa_offset .uleb128 80 .byte 0x8c # DW_CFA_offset %r12 .uleb128 2 .align 8.LENDFDE:⌨️ 快捷键说明
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