| /* Copyright (C) 2003-2014 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 <sysdep.h> |
| #include <atomic.h> |
| #include <kernel-features.h> /* Need __ASSUME_PRIVATE_FUTEX. */ |
| #include <tls.h> /* Need THREAD_*, and header.*. */ |
| |
| /* HPPA only has one atomic read and modify memory operation, |
| load and clear, so hppa uses a kernel helper routine to implement |
| compare_and_exchange. See atomic.h for the userspace calling |
| sequence. */ |
| |
| #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 |
| |
| /* Initialize locks to zero. */ |
| #define LLL_MUTEX_LOCK_INITIALIZER (0) |
| |
| #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 |
| |
| /* Type for lock object. */ |
| typedef int lll_lock_t; |
| |
| #define lll_futex_wait(futexp, val, private) \ |
| lll_futex_timed_wait (futexp, val, 0, 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)); \ |
| __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); \ |
| __ret; \ |
| }) |
| |
| #define lll_private_futex_wait(futex, val) \ |
| lll_private_futex_timed_wait (futex, val, NULL) |
| |
| #ifdef __ASSUME_PRIVATE_FUTEX |
| # define lll_private_futex_timed_wait(futexp, val, timespec) \ |
| ({ \ |
| INTERNAL_SYSCALL_DECL (__err); \ |
| long int __ret; \ |
| __ret = INTERNAL_SYSCALL (futex, __err, 4, \ |
| (futexp), FUTEX_WAIT | FUTEX_PRIVATE_FLAG, \ |
| (val), (timespec)); \ |
| __ret; \ |
| }) |
| |
| # define lll_private_futex_wake(futexp, nr) \ |
| ({ \ |
| INTERNAL_SYSCALL_DECL (__err); \ |
| long int __ret; \ |
| __ret = INTERNAL_SYSCALL (futex, __err, 4, \ |
| (futexp), FUTEX_WAKE | FUTEX_PRIVATE_FLAG, \ |
| (nr), 0); \ |
| __ret; \ |
| }) |
| |
| #else |
| |
| # define lll_private_futex_timed_wait(futexp, val, timespec) \ |
| ({ \ |
| INTERNAL_SYSCALL_DECL (__err); \ |
| long int __ret, __op; \ |
| __op = FUTEX_WAIT | THREAD_GETMEM (THREAD_SELF, header.private_futex); \ |
| __ret = INTERNAL_SYSCALL (futex, __err, 4, \ |
| (futexp), __op, (val), (timespec)); \ |
| __ret; \ |
| }) |
| |
| # define lll_private_futex_wake(futexp, nr) \ |
| ({ \ |
| INTERNAL_SYSCALL_DECL (__err); \ |
| long int __ret, __op; \ |
| __op = FUTEX_WAKE | THREAD_GETMEM (THREAD_SELF, header.private_futex); \ |
| __ret = INTERNAL_SYSCALL (futex, __err, 4, \ |
| (futexp), __op, (nr), 0); \ |
| __ret; \ |
| }) |
| #endif |
| |
| /* 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)); \ |
| __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_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); \ |
| __ret; \ |
| }) |
| |
| 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(futex, id) \ |
| __lll_robust_trylock (&(futex), id) |
| |
| 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(futex) __lll_cond_trylock (&(futex)) |
| |
| static inline int |
| __attribute__ ((always_inline)) |
| __lll_trylock (int *futex) |
| { |
| return atomic_compare_and_exchange_val_acq (futex, 1, 0) != 0; |
| } |
| #define lll_trylock(futex) __lll_trylock (&(futex)) |
| |
| extern void __lll_lock_wait (lll_lock_t *futex, int private) attribute_hidden; |
| extern void __lll_lock_wait_private (lll_lock_t *futex) attribute_hidden; |
| |
| static inline void __attribute__((always_inline)) |
| __lll_mutex_lock(lll_lock_t *futex, int private) |
| { |
| int val = atomic_compare_and_exchange_val_acq (futex, 1, 0); |
| |
| if (__builtin_expect (val != 0, 0)) |
| { |
| if (__builtin_constant_p (private) && private == LLL_PRIVATE) |
| __lll_lock_wait_private (futex); |
| else |
| __lll_lock_wait (futex, private); |
| } |
| } |
| #define lll_mutex_lock(futex, private) __lll_mutex_lock (&(futex), private) |
| #define lll_lock(lock, private) lll_mutex_lock (lock, private) |
| |
| extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; |
| |
| 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) |
| |
| #define lll_robust_cond_lock(futex, id, private) \ |
| __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private) |
| |
| static inline void |
| __attribute__ ((always_inline)) |
| __lll_cond_lock (int *futex, int private) |
| { |
| int val = atomic_compare_and_exchange_val_acq (futex, 2, 0); |
| |
| if (__builtin_expect (val != 0, 0)) |
| __lll_lock_wait (futex, private); |
| } |
| #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) |
| |
| extern int __lll_timedlock_wait (lll_lock_t *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 val = atomic_compare_and_exchange_val_acq (futex, 1, 0); |
| int result = 0; |
| |
| if (__builtin_expect (val != 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 val = atomic_exchange_rel (futex, 0); \ |
| if (__builtin_expect (val > 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 val = atomic_exchange_rel (futex, 0); \ |
| if (__builtin_expect (val & 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) |
| |
| /* Our internal lock implementation is identical to the binary-compatible |
| mutex implementation. */ |
| #define LLL_LOCK_INITIALIZER (0) |
| #define LLL_LOCK_INITIALIZER_CONST (0) |
| #define LLL_LOCK_INITIALIZER_LOCKED (1) |
| |
| #define THREAD_INIT_LOCK(PD, LOCK) \ |
| (PD)->LOCK = LLL_LOCK_INITIALIZER |
| |
| /* 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 */ |
