| /* Copyright (C) 2003-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Jakub Jelinek <jakub@redhat.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> |
| |
| #include <lowlevellock-futex.h> |
| |
| static inline int |
| __attribute__ ((always_inline)) |
| __lll_trylock (int *futex) |
| { |
| return atomic_compare_and_exchange_val_24_acq (futex, 1, 0) != 0; |
| } |
| #define lll_trylock(futex) __lll_trylock (&(futex)) |
| |
| static inline int |
| __attribute__ ((always_inline)) |
| __lll_cond_trylock (int *futex) |
| { |
| return atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0; |
| } |
| #define lll_cond_trylock(futex) __lll_cond_trylock (&(futex)) |
| |
| |
| extern void __lll_lock_wait_private (int *futex) attribute_hidden; |
| extern void __lll_lock_wait (int *futex, int private) attribute_hidden; |
| |
| static inline void |
| __attribute__ ((always_inline)) |
| __lll_lock (int *futex, int private) |
| { |
| int val = atomic_compare_and_exchange_val_24_acq (futex, 1, 0); |
| |
| if (__glibc_unlikely (val != 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 void |
| __attribute__ ((always_inline)) |
| __lll_cond_lock (int *futex, int private) |
| { |
| int val = atomic_compare_and_exchange_val_24_acq (futex, 2, 0); |
| |
| if (__glibc_unlikely (val != 0)) |
| __lll_lock_wait (futex, private); |
| } |
| #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) |
| |
| |
| extern int __lll_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_24_acq (futex, 1, 0); |
| int result = 0; |
| |
| if (__glibc_unlikely (val != 0)) |
| result = __lll_timedlock_wait (futex, abstime, private); |
| return result; |
| } |
| #define lll_timedlock(futex, abstime, private) \ |
| __lll_timedlock (&(futex), abstime, private) |
| |
| #define lll_unlock(lock, private) \ |
| ((void) ({ \ |
| int *__futex = &(lock); \ |
| int __private = (private); \ |
| int __val = atomic_exchange_24_rel (__futex, 0); \ |
| if (__glibc_unlikely (__val > 1)) \ |
| 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 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 */ |