glibc/sysdeps/unix/sysv/linux/lowlevellock-futex.h
Adhemerval Zanella ce7eb0e903 nptl: Cleanup cancellation macros
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.
2019-01-03 18:38:16 -02:00

142 lines
5.4 KiB
C

/* Low-level locking access to futex facilities. Linux version.
Copyright (C) 2005-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#ifndef _LOWLEVELLOCK_FUTEX_H
#define _LOWLEVELLOCK_FUTEX_H 1
#ifndef __ASSEMBLER__
#include <sysdep.h>
#include <tls.h>
#include <kernel-features.h>
#endif
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
#define FUTEX_REQUEUE 3
#define FUTEX_CMP_REQUEUE 4
#define FUTEX_WAKE_OP 5
#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1)
#define FUTEX_LOCK_PI 6
#define FUTEX_UNLOCK_PI 7
#define FUTEX_TRYLOCK_PI 8
#define FUTEX_WAIT_BITSET 9
#define FUTEX_WAKE_BITSET 10
#define FUTEX_WAIT_REQUEUE_PI 11
#define FUTEX_CMP_REQUEUE_PI 12
#define FUTEX_PRIVATE_FLAG 128
#define FUTEX_CLOCK_REALTIME 256
#define FUTEX_BITSET_MATCH_ANY 0xffffffff
/* Values for 'private' parameter of locking macros. Yes, the
definition seems to be backwards. But it is not. The bit will be
reversed before passing to the system call. */
#define LLL_PRIVATE 0
#define LLL_SHARED FUTEX_PRIVATE_FLAG
#ifndef __ASSEMBLER__
#if IS_IN (libc) || IS_IN (rtld)
/* In libc.so or ld.so all futexes are private. */
# define __lll_private_flag(fl, private) \
({ \
/* Prevent warnings in callers of this macro. */ \
int __lll_private_flag_priv __attribute__ ((unused)); \
__lll_private_flag_priv = (private); \
((fl) | FUTEX_PRIVATE_FLAG); \
})
#else
# define __lll_private_flag(fl, private) \
(((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
#endif
#define lll_futex_syscall(nargs, futexp, op, ...) \
({ \
INTERNAL_SYSCALL_DECL (__err); \
long int __ret = INTERNAL_SYSCALL (futex, __err, nargs, futexp, op, \
__VA_ARGS__); \
(__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret, __err)) \
? -INTERNAL_SYSCALL_ERRNO (__ret, __err) : 0); \
})
#define lll_futex_wait(futexp, val, private) \
lll_futex_timed_wait (futexp, val, NULL, private)
#define lll_futex_timed_wait(futexp, val, timeout, private) \
lll_futex_syscall (4, futexp, \
__lll_private_flag (FUTEX_WAIT, private), \
val, timeout)
#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \
lll_futex_syscall (6, futexp, \
__lll_private_flag (FUTEX_WAIT_BITSET | (clockbit), \
private), \
val, timeout, NULL /* Unused. */, \
FUTEX_BITSET_MATCH_ANY)
#define lll_futex_wake(futexp, nr, private) \
lll_futex_syscall (4, futexp, \
__lll_private_flag (FUTEX_WAKE, private), nr, 0)
/* Returns non-zero if error happened, zero if success. */
#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
lll_futex_syscall (6, futexp, \
__lll_private_flag (FUTEX_CMP_REQUEUE, private), \
nr_wake, nr_move, mutex, val)
/* Returns non-zero if error happened, zero if success. */
#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
lll_futex_syscall (6, futexp, \
__lll_private_flag (FUTEX_WAKE_OP, private), \
nr_wake, nr_wake2, futexp2, \
FUTEX_OP_CLEAR_WAKE_IF_GT_ONE)
/* Priority Inheritance support. */
#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
mutex, private) \
lll_futex_syscall (5, futexp, \
__lll_private_flag (FUTEX_WAIT_REQUEUE_PI \
| (clockbit), private), \
val, timeout, mutex)
#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, \
val, private) \
lll_futex_syscall (6, futexp, \
__lll_private_flag (FUTEX_CMP_REQUEUE_PI, \
private), \
nr_wake, nr_move, mutex, val)
/* Cancellable futex macros. */
#define lll_futex_wait_cancel(futexp, val, private) \
({ \
int __oldtype = CANCEL_ASYNC (); \
long int __err = lll_futex_wait (futexp, val, LLL_SHARED); \
CANCEL_RESET (__oldtype); \
__err; \
})
#endif /* !__ASSEMBLER__ */
#endif /* lowlevellock-futex.h */