mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-30 14:31:14 +00:00
146 lines
5.6 KiB
C
146 lines
5.6 KiB
C
/* Low-level locking access to futex facilities. Linux version.
|
|
Copyright (C) 2005-2016 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. */
|
|
# ifdef __ASSUME_PRIVATE_FUTEX
|
|
# 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) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
|
|
# endif
|
|
#else
|
|
# ifdef __ASSUME_PRIVATE_FUTEX
|
|
# define __lll_private_flag(fl, private) \
|
|
(((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
|
|
# else
|
|
# define __lll_private_flag(fl, private) \
|
|
(__builtin_constant_p (private) \
|
|
? ((private) == 0 \
|
|
? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \
|
|
: (fl)) \
|
|
: ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG) \
|
|
& THREAD_GETMEM (THREAD_SELF, header.private_futex))))
|
|
# endif
|
|
#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)
|
|
|
|
#endif /* !__ASSEMBLER__ */
|
|
|
|
#endif /* lowlevellock-futex.h */
|