mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-04 02:40:06 +00:00
314 lines
10 KiB
C
314 lines
10 KiB
C
/* Copyright (C) 2003, 2004, 2006-2008, 2009 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
|
|
|
|
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 <kernel-features.h>
|
|
|
|
#ifndef __NR_futex
|
|
# define __NR_futex 221
|
|
#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_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(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 \
|
|
{ \
|
|
INTERNAL_SYSCALL_DECL (__err); \
|
|
int *__futexp = &(futexv); \
|
|
\
|
|
atomic_or (__futexp, FUTEX_OWNER_DIED); \
|
|
INTERNAL_SYSCALL (futex, __err, 4, __futexp, \
|
|
__lll_private_flag (FUTEX_WAKE, private), 1, 0); \
|
|
} \
|
|
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); \
|
|
})
|
|
|
|
|
|
#ifdef UP
|
|
# define __lll_acq_instr ""
|
|
# define __lll_rel_instr ""
|
|
#else
|
|
# define __lll_acq_instr "isync"
|
|
# ifdef _ARCH_PWR4
|
|
/*
|
|
* Newer powerpc64 processors support the new "light weight" sync (lwsync)
|
|
* So if the build is using -mcpu=[power4,power5,power5+,970] we can
|
|
* safely use lwsync.
|
|
*/
|
|
# define __lll_rel_instr "lwsync"
|
|
# else
|
|
/*
|
|
* Older powerpc32 processors don't support the new "light weight"
|
|
* sync (lwsync). So the only safe option is to use normal sync
|
|
* for all powerpc32 applications.
|
|
*/
|
|
# define __lll_rel_instr "sync"
|
|
# endif
|
|
#endif
|
|
|
|
/* Set *futex to ID if it is 0, atomically. Returns the old value */
|
|
#define __lll_robust_trylock(futex, id) \
|
|
({ int __val; \
|
|
__asm __volatile ("1: lwarx %0,0,%2" MUTEX_HINT_ACQ "\n" \
|
|
" cmpwi 0,%0,0\n" \
|
|
" bne 2f\n" \
|
|
" stwcx. %3,0,%2\n" \
|
|
" bne- 1b\n" \
|
|
"2: " __lll_acq_instr \
|
|
: "=&r" (__val), "=m" (*futex) \
|
|
: "r" (futex), "r" (id), "m" (*futex) \
|
|
: "cr0", "memory"); \
|
|
__val; \
|
|
})
|
|
|
|
#define lll_robust_trylock(lock, id) __lll_robust_trylock (&(lock), id)
|
|
|
|
/* Set *futex to 1 if it is 0, atomically. Returns the old value */
|
|
#define __lll_trylock(futex) __lll_robust_trylock (futex, 1)
|
|
|
|
#define lll_trylock(lock) __lll_trylock (&(lock))
|
|
|
|
/* Set *futex to 2 if it is 0, atomically. Returns the old value */
|
|
#define __lll_cond_trylock(futex) __lll_robust_trylock (futex, 2)
|
|
|
|
#define lll_cond_trylock(lock) __lll_cond_trylock (&(lock))
|
|
|
|
|
|
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;
|
|
|
|
#define lll_lock(lock, private) \
|
|
(void) ({ \
|
|
int *__futex = &(lock); \
|
|
if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
|
|
0) != 0) \
|
|
{ \
|
|
if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
|
|
__lll_lock_wait_private (__futex); \
|
|
else \
|
|
__lll_lock_wait (__futex, private); \
|
|
} \
|
|
})
|
|
|
|
#define lll_robust_lock(lock, id, private) \
|
|
({ \
|
|
int *__futex = &(lock); \
|
|
int __val = 0; \
|
|
if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
|
|
0), 0)) \
|
|
__val = __lll_robust_lock_wait (__futex, private); \
|
|
__val; \
|
|
})
|
|
|
|
#define lll_cond_lock(lock, private) \
|
|
(void) ({ \
|
|
int *__futex = &(lock); \
|
|
if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 2, 0),\
|
|
0) != 0) \
|
|
__lll_lock_wait (__futex, private); \
|
|
})
|
|
|
|
#define lll_robust_cond_lock(lock, id, private) \
|
|
({ \
|
|
int *__futex = &(lock); \
|
|
int __val = 0; \
|
|
int __id = id | FUTEX_WAITERS; \
|
|
if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, __id,\
|
|
0), 0)) \
|
|
__val = __lll_robust_lock_wait (__futex, private); \
|
|
__val; \
|
|
})
|
|
|
|
|
|
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;
|
|
|
|
#define lll_timedlock(lock, abstime, private) \
|
|
({ \
|
|
int *__futex = &(lock); \
|
|
int __val = 0; \
|
|
if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
|
|
0) != 0) \
|
|
__val = __lll_timedlock_wait (__futex, abstime, private); \
|
|
__val; \
|
|
})
|
|
|
|
#define lll_robust_timedlock(lock, abstime, id, private) \
|
|
({ \
|
|
int *__futex = &(lock); \
|
|
int __val = 0; \
|
|
if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
|
|
0), 0)) \
|
|
__val = __lll_robust_timedlock_wait (__futex, abstime, private); \
|
|
__val; \
|
|
})
|
|
|
|
#define lll_unlock(lock, private) \
|
|
((void) ({ \
|
|
int *__futex = &(lock); \
|
|
int __val = atomic_exchange_rel (__futex, 0); \
|
|
if (__builtin_expect (__val > 1, 0)) \
|
|
lll_futex_wake (__futex, 1, private); \
|
|
}))
|
|
|
|
#define lll_robust_unlock(lock, private) \
|
|
((void) ({ \
|
|
int *__futex = &(lock); \
|
|
int __val = atomic_exchange_rel (__futex, 0); \
|
|
if (__builtin_expect (__val & FUTEX_WAITERS, 0)) \
|
|
lll_futex_wake (__futex, 1, private); \
|
|
}))
|
|
|
|
#define lll_islocked(futex) \
|
|
(futex != 0)
|
|
|
|
|
|
/* Initializers for lock. */
|
|
#define LLL_LOCK_INITIALIZER (0)
|
|
#define LLL_LOCK_INITIALIZER_LOCKED (1)
|
|
|
|
/* The states of a lock are:
|
|
0 - untaken
|
|
1 - taken by one user
|
|
>1 - taken by more users */
|
|
|
|
/* The kernel notifies a process which uses CLONE_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 */
|