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342 lines
12 KiB
C
342 lines
12 KiB
C
/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _LOWLEVELLOCK_H
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#define _LOWLEVELLOCK_H 1
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#include <time.h>
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#include <sys/param.h>
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#include <bits/pthreadtypes.h>
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#ifndef LOCK_INSTR
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# ifdef UP
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# define LOCK_INSTR /* nothing */
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# else
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# define LOCK_INSTR "lock;"
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# endif
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#endif
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#define SYS_futex 202
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#define FUTEX_WAIT 0
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#define FUTEX_WAKE 1
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/* Initializer for compatibility lock. */
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#define LLL_MUTEX_LOCK_INITIALIZER (0)
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#define LLL_MUTEX_LOCK_INITIALIZER_LOCKED (1)
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#define LLL_MUTEX_LOCK_INITIALIZER_WAITERS (2)
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/* Delay in spinlock loop. */
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#define BUSY_WAIT_NOP asm ("rep; nop")
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#define lll_futex_wait(futex, val) \
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do { \
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int __ignore; \
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register __typeof (val) _val asm ("edx") = (val); \
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__asm __volatile ("xorq %%r10, %%r10\n\t" \
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"syscall" \
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: "=a" (__ignore) \
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: "0" (SYS_futex), "D" (futex), "S" (FUTEX_WAIT), \
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"d" (_val) \
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: "memory", "cc", "r10", "r11", "cx"); \
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} while (0)
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#define lll_futex_wake(futex, nr) \
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do { \
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int __ignore; \
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register __typeof (nr) _nr asm ("edx") = (nr); \
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__asm __volatile ("syscall" \
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: "=a" (__ignore) \
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: "0" (SYS_futex), "D" (futex), "S" (FUTEX_WAKE), \
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"d" (_nr) \
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: "memory", "cc", "r10", "r11", "cx"); \
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} while (0)
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/* Does not preserve %eax and %ecx. */
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extern int __lll_mutex_lock_wait (int *__futex, int __val) attribute_hidden;
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/* Does not preserver %eax, %ecx, and %edx. */
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extern int __lll_mutex_timedlock_wait (int *__futex, int __val,
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const struct timespec *__abstime)
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attribute_hidden;
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/* Preserves all registers but %eax. */
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extern int __lll_mutex_unlock_wait (int *__futex) attribute_hidden;
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/* NB: in the lll_mutex_trylock macro we simply return the value in %eax
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after the cmpxchg instruction. In case the operation succeded this
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value is zero. In case the operation failed, the cmpxchg instruction
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has loaded the current value of the memory work which is guaranteed
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to be nonzero. */
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#define lll_mutex_trylock(futex) \
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({ int ret; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %2, %1" \
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: "=a" (ret), "=m" (futex) \
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: "r" (LLL_MUTEX_LOCK_INITIALIZER_LOCKED), "m" (futex),\
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"0" (LLL_MUTEX_LOCK_INITIALIZER) \
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: "memory"); \
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ret; })
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#define lll_mutex_cond_trylock(futex) \
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({ int ret; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %2, %1" \
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: "=a" (ret), "=m" (futex) \
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: "r" (LLL_MUTEX_LOCK_INITIALIZER_WAITERS), \
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"m" (futex), "0" (LLL_MUTEX_LOCK_INITIALIZER) \
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: "memory"); \
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ret; })
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#define lll_mutex_lock(futex) \
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(void) ({ int ignore1, ignore2, ignore3; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %0, %2\n\t" \
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"jnz 1f\n\t" \
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".subsection 1\n" \
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"1:\tleaq %2, %%rdi\n\t" \
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"subq $128, %%rsp\n\t" \
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"callq __lll_mutex_lock_wait\n\t" \
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"addq $128, %%rsp\n\t" \
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"jmp 2f\n\t" \
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".previous\n" \
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"2:" \
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: "=S" (ignore1), "=&D" (ignore2), "=m" (futex),\
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"=a" (ignore3) \
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: "0" (1), "m" (futex), "3" (0) \
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: "cx", "r11", "cc", "memory"); })
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#define lll_mutex_cond_lock(futex) \
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(void) ({ int ignore1, ignore2, ignore3; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %0, %2\n\t" \
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"jnz 1f\n\t" \
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".subsection 1\n" \
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"1:\tleaq %2, %%rdi\n\t" \
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"subq $128, %%rsp\n\t" \
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"callq __lll_mutex_lock_wait\n\t" \
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"addq $128, %%rsp\n\t" \
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"jmp 2f\n\t" \
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".previous\n" \
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"2:" \
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: "=S" (ignore1), "=&D" (ignore2), "=m" (futex),\
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"=a" (ignore3) \
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: "0" (2), "m" (futex), "3" (0) \
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: "cx", "r11", "cc", "memory"); })
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#define lll_mutex_timedlock(futex, timeout) \
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({ int result, ignore1, ignore2, ignore3; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %2, %4\n\t" \
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"jnz 1f\n\t" \
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".subsection 1\n" \
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"1:\tleaq %4, %%rdi\n\t" \
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"movq %8, %%rdx\n\t" \
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"subq $128, %%rsp\n\t" \
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"callq __lll_mutex_timedlock_wait\n\t" \
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"addq $128, %%rsp\n\t" \
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"jmp 2f\n\t" \
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".previous\n" \
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"2:" \
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: "=a" (result), "=&D" (ignore1), "=S" (ignore2), \
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"=&d" (ignore3), "=m" (futex) \
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: "0" (0), "2" (1), "m" (futex), "m" (timeout) \
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: "memory", "cx", "cc", "r10", "r11"); \
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result; })
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#define lll_mutex_unlock(futex) \
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(void) ({ int ignore; \
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__asm __volatile (LOCK_INSTR "decl %0\n\t" \
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"jne 1f\n\t" \
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".subsection 1\n" \
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"1:\tleaq %0, %%rdi\n\t" \
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"subq $128, %%rsp\n\t" \
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"callq __lll_mutex_unlock_wake\n\t" \
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"addq $128, %%rsp\n\t" \
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"jmp 2f\n\t" \
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".previous\n" \
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"2:" \
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: "=m" (futex), "=&D" (ignore) \
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: "m" (futex) \
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: "ax", "cx", "r11", "cc", "memory"); })
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#define lll_mutex_islocked(futex) \
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(futex != LLL_MUTEX_LOCK_INITIALIZER)
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/* We have a separate internal lock implementation which is not tied
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to binary compatibility. */
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/* Type for lock object. */
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typedef int lll_lock_t;
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/* Initializers for lock. */
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#define LLL_LOCK_INITIALIZER (0)
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#define LLL_LOCK_INITIALIZER_LOCKED (1)
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extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
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/* The states of a lock are:
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0 - untaken
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1 - taken by one user
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2 - taken by more users */
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#if defined NOT_IN_libc || defined UP
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# define lll_trylock(futex) lll_mutex_trylock (futex)
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# define lll_lock(futex) lll_mutex_lock (futex)
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# define lll_unlock(futex) lll_mutex_unlock (futex)
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#else
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/* Special versions of the macros for use in libc itself. They avoid
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the lock prefix when the thread library is not used.
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The code sequence to avoid unnecessary lock prefixes is what the AMD
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guys suggested. If you do not like it, bring it up with AMD.
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XXX In future we might even want to avoid it on UP machines. */
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# define lll_trylock(futex) \
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({ unsigned char ret; \
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__asm __volatile ("cmpl $0, __libc_multiple_threads(%%rip)\n\t" \
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"je 0f\n\t" \
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"lock; cmpxchgl %2, %1\n\t" \
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"jmp 1f\n" \
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"0:\tcmpxchgl %2, %1\n\t" \
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"1:setne %0" \
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: "=a" (ret), "=m" (futex) \
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: "r" (LLL_MUTEX_LOCK_INITIALIZER_LOCKED), "m" (futex),\
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"0" (LLL_MUTEX_LOCK_INITIALIZER) \
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: "memory"); \
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ret; })
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# define lll_lock(futex) \
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(void) ({ int ignore1, ignore2, ignore3; \
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__asm __volatile ("cmpl $0, __libc_multiple_threads(%%rip)\n\t" \
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"je 0f\n\t" \
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"lock; cmpxchgl %0, %2\n\t" \
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"jnz 1f\n\t" \
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"jmp 2f\n" \
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"0:\tcmpxchgl %0, %2\n\t" \
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"jnz 1f\n\t" \
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".subsection 1\n" \
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"1:\tleaq %2, %%rdi\n\t" \
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"subq $128, %%rsp\n\t" \
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"callq __lll_mutex_lock_wait\n\t" \
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"addq $128, %%rsp\n\t" \
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"jmp 2f\n\t" \
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".previous\n" \
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"2:" \
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: "=S" (ignore1), "=&D" (ignore2), "=m" (futex),\
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"=a" (ignore3) \
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: "0" (1), "m" (futex), "3" (0) \
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: "cx", "r11", "cc", "memory"); })
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# define lll_unlock(futex) \
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(void) ({ int ignore; \
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__asm __volatile ("cmpl $0, __libc_multiple_threads(%%rip)\n\t" \
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"je 0f\n\t" \
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"lock; decl %0\n\t" \
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"jne 1f\n\t" \
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"jmp 2f\n" \
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"0:\tdecl %0\n\t" \
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"jne 1f\n\t" \
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".subsection 1\n" \
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"1:\tleaq %0, %%rdi\n\t" \
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"subq $128, %%rsp\n\t" \
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"callq __lll_mutex_unlock_wake\n\t" \
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"addq $128, %%rsp\n\t" \
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"jmp 2f\n\t" \
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".previous\n" \
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"2:" \
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: "=m" (futex), "=&D" (ignore) \
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: "m" (futex) \
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: "ax", "cx", "r11", "cc", "memory"); })
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#endif
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#define lll_islocked(futex) \
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(futex != LLL_MUTEX_LOCK_INITIALIZER)
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/* The kernel notifies a process with uses CLONE_CLEARTID via futex
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wakeup when the clone terminates. The memory location contains the
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thread ID while the clone is running and is reset to zero
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afterwards.
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The macro parameter must not have any side effect. */
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#define lll_wait_tid(tid) \
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do { \
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int __ignore; \
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register __typeof (tid) _tid asm ("edx") = (tid); \
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if (_tid != 0) \
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__asm __volatile ("xorq %%r10, %%r10\n\t" \
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"1:\tmovq %2, %%rax\n\t" \
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"syscall\n\t" \
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"cmpl $0, (%%rdi)\n\t" \
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"jne 1b" \
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: "=&a" (__ignore) \
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: "S" (FUTEX_WAIT), "i" (SYS_futex), "D" (&tid), \
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"d" (_tid) \
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: "memory", "cc", "r10", "r11", "cx"); \
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} while (0)
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extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime)
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attribute_hidden;
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#define lll_timedwait_tid(tid, abstime) \
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({ \
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int __result = 0; \
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if (tid != 0) \
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{ \
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if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) \
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__result = EINVAL; \
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else \
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__result = __lll_timedwait_tid (&tid, abstime); \
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} \
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__result; })
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/* Conditional variable handling. */
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extern void __lll_cond_wait (pthread_cond_t *cond) attribute_hidden;
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extern int __lll_cond_timedwait (pthread_cond_t *cond,
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const struct timespec *abstime)
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attribute_hidden;
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extern void __lll_cond_wake (pthread_cond_t *cond) attribute_hidden;
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extern void __lll_cond_broadcast (pthread_cond_t *cond) attribute_hidden;
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#define lll_cond_wait(cond) \
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__lll_cond_wait (cond)
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#define lll_cond_timedwait(cond, abstime) \
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__lll_cond_timedwait (cond, abstime)
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#define lll_cond_wake(cond) \
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__lll_cond_wake (cond)
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#define lll_cond_broadcast(cond) \
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__lll_cond_broadcast (cond)
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#endif /* lowlevellock.h */
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