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glibc/ports/sysdeps/unix/sysv/linux/alpha/nptl/lowlevellock.h
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/* Copyright (C) 2003, 2004, 2006, 2007 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_H | |
#define _LOWLEVELLOCK_H 1 | |
#include <time.h> | |
#include <sys/param.h> | |
#include <bits/pthreadtypes.h> | |
#include <atomic.h> | |
#include <sysdep.h> | |
#include <kernel-features.h> | |
#define __NR_futex 394 | |
#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_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 | |
#if !defined NOT_IN_libc || defined IS_IN_rtld | |
/* In libc.so or ld.so all futexes are private. */ | |
# ifdef __ASSUME_PRIVATE_FUTEX | |
# define __lll_private_flag(fl, 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_wait(futexp, val, private) \ | |
lll_futex_timed_wait (futexp, val, NULL, private) | |
#define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \ | |
({ \ | |
INTERNAL_SYSCALL_DECL (__err); \ | |
long int __ret; \ | |
int __op = FUTEX_WAIT_BITSET | clockbit; \ | |
\ | |
__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ | |
__lll_private_flag (__op, private), \ | |
(val), (timespec), NULL /* Unused. */, \ | |
FUTEX_BITSET_MATCH_ANY); \ | |
__ret; \ | |
}) | |
#define lll_futex_timed_wait(futexp, val, timespec, private) \ | |
({ \ | |
INTERNAL_SYSCALL_DECL (__err); \ | |
long int __ret; \ | |
__ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \ | |
__lll_private_flag (FUTEX_WAIT, private), \ | |
(val), (timespec)); \ | |
INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret; \ | |
}) | |
#define lll_futex_wake(futexp, nr, private) \ | |
({ \ | |
INTERNAL_SYSCALL_DECL (__err); \ | |
long int __ret; \ | |
__ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \ | |
__lll_private_flag (FUTEX_WAKE, private), \ | |
(nr), 0); \ | |
INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret; \ | |
}) | |
#define lll_robust_dead(futexv, private) \ | |
do \ | |
{ \ | |
int *__futexp = &(futexv); \ | |
atomic_or (__futexp, FUTEX_OWNER_DIED); \ | |
lll_futex_wake (__futexp, 1, private); \ | |
} \ | |
while (0) | |
/* Returns non-zero if error happened, zero if success. */ | |
#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ | |
({ \ | |
INTERNAL_SYSCALL_DECL (__err); \ | |
long int __ret; \ | |
__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ | |
__lll_private_flag (FUTEX_CMP_REQUEUE, private),\ | |
(nr_wake), (nr_move), (mutex), (val)); \ | |
INTERNAL_SYSCALL_ERROR_P (__ret, __err); \ | |
}) | |
/* Returns non-zero if error happened, zero if success. */ | |
#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ | |
({ \ | |
INTERNAL_SYSCALL_DECL (__err); \ | |
long int __ret; \ | |
__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ | |
__lll_private_flag (FUTEX_WAKE_OP, private), \ | |
(nr_wake), (nr_wake2), (futexp2), \ | |
FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \ | |
INTERNAL_SYSCALL_ERROR_P (__ret, __err); \ | |
}) | |
static inline int __attribute__((always_inline)) | |
__lll_trylock(int *futex) | |
{ | |
return atomic_compare_and_exchange_val_acq (futex, 1, 0) != 0; | |
} | |
#define lll_trylock(lock) __lll_trylock (&(lock)) | |
static inline int __attribute__((always_inline)) | |
__lll_cond_trylock(int *futex) | |
{ | |
return atomic_compare_and_exchange_val_acq (futex, 2, 0) != 0; | |
} | |
#define lll_cond_trylock(lock) __lll_cond_trylock (&(lock)) | |
static inline int __attribute__((always_inline)) | |
__lll_robust_trylock(int *futex, int id) | |
{ | |
return atomic_compare_and_exchange_val_acq (futex, id, 0) != 0; | |
} | |
#define lll_robust_trylock(lock, id) \ | |
__lll_robust_trylock (&(lock), id) | |
extern void __lll_lock_wait_private (int *futex) attribute_hidden; | |
extern void __lll_lock_wait (int *futex, int private) attribute_hidden; | |
extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; | |
static inline void __attribute__((always_inline)) | |
__lll_lock(int *futex, int private) | |
{ | |
if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0) | |
{ | |
if (__builtin_constant_p (private) && private == LLL_PRIVATE) | |
__lll_lock_wait_private (futex); | |
else | |
__lll_lock_wait (futex, private); | |
} | |
} | |
#define lll_lock(futex, private) __lll_lock (&(futex), private) | |
static inline int __attribute__ ((always_inline)) | |
__lll_robust_lock (int *futex, int id, int private) | |
{ | |
int result = 0; | |
if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0) | |
result = __lll_robust_lock_wait (futex, private); | |
return result; | |
} | |
#define lll_robust_lock(futex, id, private) \ | |
__lll_robust_lock (&(futex), id, private) | |
static inline void __attribute__ ((always_inline)) | |
__lll_cond_lock (int *futex, int private) | |
{ | |
if (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0) | |
__lll_lock_wait (futex, private); | |
} | |
#define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) | |
#define lll_robust_cond_lock(futex, id, private) \ | |
__lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private) | |
extern int __lll_timedlock_wait (int *futex, const struct timespec *, | |
int private) attribute_hidden; | |
extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, | |
int private) attribute_hidden; | |
static inline int __attribute__ ((always_inline)) | |
__lll_timedlock (int *futex, const struct timespec *abstime, int private) | |
{ | |
int result = 0; | |
if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0) | |
result = __lll_timedlock_wait (futex, abstime, private); | |
return result; | |
} | |
#define lll_timedlock(futex, abstime, private) \ | |
__lll_timedlock (&(futex), abstime, private) | |
static inline int __attribute__ ((always_inline)) | |
__lll_robust_timedlock (int *futex, const struct timespec *abstime, | |
int id, int private) | |
{ | |
int result = 0; | |
if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0) | |
result = __lll_robust_timedlock_wait (futex, abstime, private); | |
return result; | |
} | |
#define lll_robust_timedlock(futex, abstime, id, private) \ | |
__lll_robust_timedlock (&(futex), abstime, id, private) | |
#define __lll_unlock(futex, private) \ | |
(void) \ | |
({ int *__futex = (futex); \ | |
int __oldval = atomic_exchange_rel (__futex, 0); \ | |
if (__builtin_expect (__oldval > 1, 0)) \ | |
lll_futex_wake (__futex, 1, private); \ | |
}) | |
#define lll_unlock(futex, private) __lll_unlock(&(futex), private) | |
#define __lll_robust_unlock(futex, private) \ | |
(void) \ | |
({ int *__futex = (futex); \ | |
int __oldval = atomic_exchange_rel (__futex, 0); \ | |
if (__builtin_expect (__oldval & FUTEX_WAITERS, 0)) \ | |
lll_futex_wake (__futex, 1, private); \ | |
}) | |
#define lll_robust_unlock(futex, private) \ | |
__lll_robust_unlock(&(futex), private) | |
#define lll_islocked(futex) \ | |
(futex != 0) | |
/* Initializers for lock. */ | |
#define LLL_LOCK_INITIALIZER (0) | |
#define LLL_LOCK_INITIALIZER_LOCKED (1) | |
/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex | |
wakeup when the clone terminates. The memory location contains the | |
thread ID while the clone is running and is reset to zero | |
afterwards. */ | |
#define lll_wait_tid(tid) \ | |
do { \ | |
__typeof (tid) __tid; \ | |
while ((__tid = (tid)) != 0) \ | |
lll_futex_wait (&(tid), __tid, LLL_SHARED); \ | |
} while (0) | |
extern int __lll_timedwait_tid (int *, const struct timespec *) | |
attribute_hidden; | |
#define lll_timedwait_tid(tid, abstime) \ | |
({ \ | |
int __res = 0; \ | |
if ((tid) != 0) \ | |
__res = __lll_timedwait_tid (&(tid), (abstime)); \ | |
__res; \ | |
}) | |
#endif /* lowlevellock.h */ |