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ce7eb0e903
This patch wraps all uses of *_{enable,disable}_asynccancel and
and *_CANCEL_{ASYNC,RESET} in either already provided macros
(lll_futex_timed_wait_cancel) or creates new ones if the
functionality is not provided (SYSCALL_CANCEL_NCS, lll_futex_wait_cancel,
and lll_futex_timed_wait_cancel).
Also for some generic implementations, the direct call of the macros
are removed since the underlying symbols are suppose to provide
cancellation support.
This is a priliminary patch intended to simplify the work required
for BZ#12683 fix. It is a refactor change, no semantic changes are
expected.
Checked on x86_64-linux-gnu and i686-linux-gnu.
* nptl/pthread_join_common.c (__pthread_timedjoin_ex): Use
lll_wait_tid with timeout.
* nptl/sem_wait.c (__old_sem_wait): Use lll_futex_wait_cancel.
* sysdeps/nptl/aio_misc.h (AIO_MISC_WAIT): Use
futex_reltimed_wait_cancelable for cancelabla mode.
* sysdeps/nptl/gai_misc.h (GAI_MISC_WAIT): Likewise.
* sysdeps/posix/open64.c (__libc_open64): Do not call cancelation
macros.
* sysdeps/posix/sigwait.c (__sigwait): Likewise.
* sysdeps/posix/waitid.c (__sigwait): Likewise.
* sysdeps/unix/sysdep.h (__SYSCALL_CANCEL_CALL,
SYSCALL_CANCEL_NCS): New macro.
* sysdeps/nptl/lowlevellock.h (lll_wait_tid): Add timeout argument.
(lll_timedwait_tid): Remove macro.
* sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_wait_tid):
Likewise.
(lll_timedwait_tid): Likewise.
* sysdeps/unix/sysv/linux/sparc/lowlevellock.h (lll_wait_tid):
Likewise.
(lll_timedwait_tid): Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_wait_tid):
Likewise.
(lll_timedwait_tid): Likewise.
* sysdeps/unix/sysv/linux/clock_nanosleep.c (__clock_nanosleep):
Use INTERNAL_SYSCALL_CANCEL.
* sysdeps/unix/sysv/linux/futex-internal.h
(futex_reltimed_wait_cancelable): Use LIBC_CANCEL_{ASYNC,RESET}
instead of __pthread_{enable,disable}_asynccancel.
* sysdeps/unix/sysv/linux/lowlevellock-futex.h
(lll_futex_wait_cancel): New macro.
268 lines
9.2 KiB
C
268 lines
9.2 KiB
C
/* Copyright (C) 2002-2019 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, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _LOWLEVELLOCK_H
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#define _LOWLEVELLOCK_H 1
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#include <stap-probe.h>
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#ifndef __ASSEMBLER__
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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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# include <kernel-features.h>
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/* <tcb-offsets.h> is generated from tcb-offsets.sym to define offsets
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and sizes of types in <tls.h> as well as <pthread.h> which includes
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<lowlevellock.h> via nptl/descr.h. Don't include <tcb-offsets.h>
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when generating <tcb-offsets.h> to avoid circular dependency which
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may lead to build hang on a many-core machine. */
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# ifndef GEN_AS_CONST_HEADERS
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# include <tcb-offsets.h>
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# endif
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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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#else
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# ifndef LOCK
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# ifdef UP
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# define LOCK
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# else
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# define LOCK lock
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# endif
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# endif
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#endif
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#include <lowlevellock-futex.h>
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/* XXX Remove when no assembler code uses futexes anymore. */
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#define SYS_futex __NR_futex
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#ifndef __ASSEMBLER__
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/* Initializer for compatibility lock. */
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#define LLL_LOCK_INITIALIZER (0)
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#define LLL_LOCK_INITIALIZER_LOCKED (1)
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#define LLL_LOCK_INITIALIZER_WAITERS (2)
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/* NB: in the lll_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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#if !IS_IN (libc) || defined UP
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# define __lll_trylock_asm LOCK_INSTR "cmpxchgl %2, %1"
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#else
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# define __lll_trylock_asm "cmpl $0, %%gs:%P5\n\t" \
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"je 0f\n\t" \
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"lock\n" \
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"0:\tcmpxchgl %2, %1"
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#endif
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#define lll_trylock(futex) \
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({ int ret; \
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__asm __volatile (__lll_trylock_asm \
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: "=a" (ret), "=m" (futex) \
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: "r" (LLL_LOCK_INITIALIZER_LOCKED), "m" (futex), \
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"0" (LLL_LOCK_INITIALIZER), \
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"i" (MULTIPLE_THREADS_OFFSET) \
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: "memory"); \
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ret; })
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#define lll_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_LOCK_INITIALIZER_WAITERS), \
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"m" (futex), "0" (LLL_LOCK_INITIALIZER) \
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: "memory"); \
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ret; })
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#if !IS_IN (libc) || defined UP
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# define __lll_lock_asm_start LOCK_INSTR "cmpxchgl %1, %2\n\t"
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#else
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# define __lll_lock_asm_start "cmpl $0, %%gs:%P6\n\t" \
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"je 0f\n\t" \
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"lock\n" \
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"0:\tcmpxchgl %1, %2\n\t"
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#endif
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#define lll_lock(futex, private) \
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(void) \
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({ int ignore1, ignore2; \
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if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
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__asm __volatile (__lll_lock_asm_start \
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"jz 18f\n\t" \
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"1:\tleal %2, %%ecx\n" \
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"2:\tcall __lll_lock_wait_private\n" \
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"18:" \
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: "=a" (ignore1), "=c" (ignore2), "=m" (futex) \
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: "0" (0), "1" (1), "m" (futex), \
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"i" (MULTIPLE_THREADS_OFFSET) \
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: "memory"); \
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else \
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{ \
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int ignore3; \
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__asm __volatile (__lll_lock_asm_start \
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"jz 18f\n\t" \
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"1:\tleal %2, %%edx\n" \
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"0:\tmovl %8, %%ecx\n" \
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"2:\tcall __lll_lock_wait\n" \
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"18:" \
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: "=a" (ignore1), "=c" (ignore2), \
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"=m" (futex), "=&d" (ignore3) \
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: "1" (1), "m" (futex), \
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"i" (MULTIPLE_THREADS_OFFSET), "0" (0), \
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"g" ((int) (private)) \
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: "memory"); \
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} \
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})
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/* Special version of lll_lock which causes the unlock function to
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always wakeup waiters. */
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#define lll_cond_lock(futex, private) \
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(void) \
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({ int ignore1, ignore2, ignore3; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %1, %2\n\t" \
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"jz 18f\n\t" \
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"1:\tleal %2, %%edx\n" \
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"0:\tmovl %7, %%ecx\n" \
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"2:\tcall __lll_lock_wait\n" \
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"18:" \
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: "=a" (ignore1), "=c" (ignore2), "=m" (futex), \
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"=&d" (ignore3) \
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: "0" (0), "1" (2), "m" (futex), "g" ((int) (private))\
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: "memory"); \
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})
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#define lll_timedlock(futex, timeout, private) \
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({ int result, ignore1, ignore2, ignore3; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %1, %3\n\t" \
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"jz 18f\n\t" \
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"1:\tleal %3, %%ecx\n" \
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"0:\tmovl %8, %%edx\n" \
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"2:\tcall __lll_timedlock_wait\n" \
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"18:" \
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: "=a" (result), "=c" (ignore1), "=&d" (ignore2), \
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"=m" (futex), "=S" (ignore3) \
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: "0" (0), "1" (1), "m" (futex), "m" (timeout), \
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"4" ((int) (private)) \
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: "memory"); \
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result; })
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extern int __lll_timedlock_elision (int *futex, short *adapt_count,
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const struct timespec *timeout,
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int private) attribute_hidden;
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#define lll_timedlock_elision(futex, adapt_count, timeout, private) \
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__lll_timedlock_elision(&(futex), &(adapt_count), timeout, private)
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#if !IS_IN (libc) || defined UP
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# define __lll_unlock_asm LOCK_INSTR "subl $1, %0\n\t"
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#else
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# define __lll_unlock_asm "cmpl $0, %%gs:%P3\n\t" \
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"je 0f\n\t" \
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"lock\n" \
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"0:\tsubl $1,%0\n\t"
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#endif
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#define lll_unlock(futex, private) \
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(void) \
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({ int ignore; \
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if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
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__asm __volatile (__lll_unlock_asm \
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"je 18f\n\t" \
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"1:\tleal %0, %%eax\n" \
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"2:\tcall __lll_unlock_wake_private\n" \
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"18:" \
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: "=m" (futex), "=&a" (ignore) \
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: "m" (futex), "i" (MULTIPLE_THREADS_OFFSET) \
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: "memory"); \
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else \
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{ \
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int ignore2; \
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__asm __volatile (__lll_unlock_asm \
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"je 18f\n\t" \
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"1:\tleal %0, %%eax\n" \
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"0:\tmovl %5, %%ecx\n" \
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"2:\tcall __lll_unlock_wake\n" \
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"18:" \
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: "=m" (futex), "=&a" (ignore), "=&c" (ignore2) \
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: "i" (MULTIPLE_THREADS_OFFSET), "m" (futex), \
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"g" ((int) (private)) \
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: "memory"); \
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} \
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})
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#define lll_islocked(futex) \
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(futex != LLL_LOCK_INITIALIZER)
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extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime)
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__attribute__ ((regparm (2))) attribute_hidden;
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/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
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wake-up 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 by the kernel
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afterwards. The kernel up to version 3.16.3 does not use the private futex
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operations for futex wake-up when the clone terminates.
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If ABSTIME is not NULL, is used a timeout for futex call. If the timeout
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occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
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The futex operation are issues with cancellable versions. */
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#define lll_wait_tid(tid, abstime) \
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({ \
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int __res = 0; \
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__typeof (tid) __tid; \
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if (abstime != NULL) \
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__res = __lll_timedwait_tid (&(tid), (abstime)); \
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else \
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/* We need acquire MO here so that we synchronize with the \
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kernel's store to 0 when the clone terminates. (see above) */ \
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while ((__tid = atomic_load_acquire (&(tid))) != 0) \
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lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED); \
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__res; \
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})
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extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
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attribute_hidden;
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extern int __lll_unlock_elision(int *lock, int private)
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attribute_hidden;
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extern int __lll_trylock_elision(int *lock, short *adapt_count)
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attribute_hidden;
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#define lll_lock_elision(futex, adapt_count, private) \
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__lll_lock_elision (&(futex), &(adapt_count), private)
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#define lll_unlock_elision(futex, adapt_count, private) \
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__lll_unlock_elision (&(futex), private)
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#define lll_trylock_elision(futex, adapt_count) \
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__lll_trylock_elision(&(futex), &(adapt_count))
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#endif /* !__ASSEMBLER__ */
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#endif /* lowlevellock.h */
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