+++ /dev/null
-/* Copyright (C) 2003-2014 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_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
-
-#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_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); \
- 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; \
- })
-
-/* 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); \
- })
-
-/* 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, timespec, clockbit, \
- mutex, private) \
- ({ \
- INTERNAL_SYSCALL_DECL (__err); \
- long int __ret; \
- int __op = FUTEX_WAIT_REQUEUE_PI | clockbit; \
- \
- __ret = INTERNAL_SYSCALL (futex, __err, 5, (futexp), \
- __lll_private_flag (__op, private), \
- (val), (timespec), mutex); \
- INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret; \
- })
-
-#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv) \
- ({ \
- INTERNAL_SYSCALL_DECL (__err); \
- long int __ret; \
- \
- __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
- __lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv),\
- (nr_wake), (nr_move), (mutex), (val)); \
- 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_base_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; \
- })
-
-/* Set *futex to 1 if it is 0, atomically. Returns the old value */
-#define __lll_trylock(futex) __lll_base_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_base_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 (__glibc_unlikely (__val > 1)) \
- lll_futex_wake (__futex, 1, private); \
- }))
-
-#define lll_robust_unlock(lock, private) \
- ((void) ({ \
- int *__futex = &(lock); \
- int __val = atomic_exchange_rel (__futex, 0); \
- if (__glibc_unlikely (__val & FUTEX_WAITERS)) \
- 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_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 */
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