/* Copyright (C) 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jakub Jelinek , 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #ifndef _LOWLEVELLOCK_H #define _LOWLEVELLOCK_H 1 #include #include #include #include #include #define SYS_futex 1230 #define FUTEX_WAIT 0 #define FUTEX_WAKE 1 #define FUTEX_REQUEUE 3 /* Initializer for compatibility lock. */ #define LLL_MUTEX_LOCK_INITIALIZER (0) #define lll_futex_clobbers \ "out5", "out6", "out7", \ /* Non-stacked integer registers, minus r8, r10, r15. */ \ "r2", "r3", "r9", "r11", "r12", "r13", "r14", "r16", "r17", "r18", \ "r19", "r20", "r21", "r22", "r23", "r24", "r25", "r26", "r27", \ "r28", "r29", "r30", "r31", \ /* Predicate registers. */ \ "p6", "p7", "p8", "p9", "p10", "p11", "p12", "p13", "p14", "p15", \ /* Non-rotating fp registers. */ \ "f6", "f7", "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \ /* Branch registers. */ \ "b6", "b7", \ "memory" #define lll_futex_wait(futex, val) lll_futex_timed_wait (futex, val, 0) #define lll_futex_timed_wait(futex, val, timespec) \ ({ \ register long int __o0 asm ("out0") = (long int) (futex); \ register long int __o1 asm ("out1") = FUTEX_WAIT; \ register int __o2 asm ("out2") = (int) (val); \ register long int __o3 asm ("out3") = (long int) (timespec); \ register long int __r8 asm ("r8"); \ register long int __r10 asm ("r10"); \ register long int __r15 asm ("r15") = SYS_futex; \ \ __asm __volatile ("break %7;;" \ : "=r" (__r8), "=r" (__r10), "=r" (__r15), \ "=r" (__o0), "=r" (__o1), "=r" (__o2), "=r" (__o3) \ : "i" (0x100000), "2" (__r15), "3" (__o0), "4" (__o1), \ "5" (__o2), "6" (__o3) \ : "out4", lll_futex_clobbers); \ __r10 == -1 ? -__r8 : __r8; \ }) #define lll_futex_wake(futex, nr) \ ({ \ register long int __o0 asm ("out0") = (long int) (futex); \ register long int __o1 asm ("out1") = FUTEX_WAKE; \ register int __o2 asm ("out2") = (int) (nr); \ register long int __r8 asm ("r8"); \ register long int __r10 asm ("r10"); \ register long int __r15 asm ("r15") = SYS_futex; \ \ __asm __volatile ("break %6;;" \ : "=r" (__r8), "=r" (__r10), "=r" (__r15), \ "=r" (__o0), "=r" (__o1), "=r" (__o2) \ : "i" (0x100000), "2" (__r15), "3" (__o0), "4" (__o1), \ "5" (__o2) \ : "out3", "out4", lll_futex_clobbers); \ __r10 == -1 ? -__r8 : __r8; \ }) #define lll_futex_requeue(futex, nr_wake, nr_move, mutex) \ ({ \ register long int __o0 asm ("out0") = (long int) (futex); \ register long int __o1 asm ("out1") = FUTEX_REQUEUE; \ register int __o2 asm ("out2") = (int) (nr_wake); \ register int __o3 asm ("out3") = (int) (nr_move); \ register long int __o4 asm ("out4") = (long int) (mutex); \ register long int __r8 asm ("r8"); \ register long int __r10 asm ("r10"); \ register long int __r15 asm ("r15") = SYS_futex; \ \ __asm __volatile ("break %8;;" \ : "=r" (__r8), "=r" (__r10), "=r" (__r15), \ "=r" (__o0), "=r" (__o1), "=r" (__o2), "=r" (__o3), \ "=r" (__o4) \ : "i" (0x100000), "2" (__r15), "3" (__o0), "4" (__o1), \ "5" (__o2), "6" (__o3), "7" (__o4) \ : lll_futex_clobbers); \ __r10 == -1 ? -__r8 : __r8; \ }) static inline int __attribute__ ((always_inline)) __lll_mutex_trylock (int *futex) { return atomic_compare_and_exchange_val_acq (futex, 1, 0) != 0; } #define lll_mutex_trylock(futex) __lll_mutex_trylock (&(futex)) extern void __lll_lock_wait (int *futex, int val) attribute_hidden; static inline void __attribute__ ((always_inline)) __lll_mutex_lock (int *futex) { int val = atomic_exchange_and_add (futex, 1); if (__builtin_expect (val != 0, 0)) __lll_lock_wait (futex, val); } #define lll_mutex_lock(futex) __lll_mutex_lock (&(futex)) static inline void __attribute__ ((always_inline)) __lll_mutex_cond_lock (int *futex) { int val = atomic_exchange_and_add (futex, 2); if (__builtin_expect (val != 0, 0)) /* Note, the val + 1 is kind of ugly here. __lll_lock_wait will add 1 again. But we added 2 to the futex value so this is the right value which will be passed to the kernel. */ __lll_lock_wait (futex, val + 1); } #define lll_mutex_cond_lock(futex) __lll_mutex_cond_lock (&(futex)) extern int __lll_timedlock_wait (int *futex, int val, const struct timespec *) attribute_hidden; static inline int __attribute__ ((always_inline)) __lll_mutex_timedlock (int *futex, const struct timespec *abstime) { int val = atomic_exchange_and_add (futex, 1); int result = 0; if (__builtin_expect (val != 0, 0)) result = __lll_timedlock_wait (futex, val, abstime); return result; } #define lll_mutex_timedlock(futex, abstime) \ __lll_mutex_timedlock (&(futex), abstime) static inline void __attribute__ ((always_inline)) __lll_mutex_unlock (int *futex) { int val = atomic_exchange_rel (futex, 0); if (__builtin_expect (val > 1, 0)) lll_futex_wake (futex, 1); } #define lll_mutex_unlock(futex) \ __lll_mutex_unlock(&(futex)) static inline void __attribute__ ((always_inline)) __lll_mutex_unlock_force (int *futex) { (void) atomic_exchange_rel (futex, 0); lll_futex_wake (futex, 1); } #define lll_mutex_unlock_force(futex) \ __lll_mutex_unlock_force(&(futex)) #define lll_mutex_islocked(futex) \ (futex != 0) /* We have a separate internal lock implementation which is not tied to binary compatibility. We can use the lll_mutex_*. */ /* Type for lock object. */ typedef int lll_lock_t; extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; /* Initializers for lock. */ #define LLL_LOCK_INITIALIZER (0) #define LLL_LOCK_INITIALIZER_LOCKED (1) #define lll_trylock(futex) lll_mutex_trylock (futex) #define lll_lock(futex) lll_mutex_lock (futex) #define lll_unlock(futex) lll_mutex_unlock (futex) #define lll_islocked(futex) lll_mutex_islocked (futex) /* The kernel notifies a process with 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); \ } \ 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; \ }) /* Conditional variable handling. */ extern void __lll_cond_wait (pthread_cond_t *cond) attribute_hidden; extern int __lll_cond_timedwait (pthread_cond_t *cond, const struct timespec *abstime) attribute_hidden; extern void __lll_cond_wake (pthread_cond_t *cond) attribute_hidden; extern void __lll_cond_broadcast (pthread_cond_t *cond) attribute_hidden; #define lll_cond_wait(cond) \ __lll_cond_wait (cond) #define lll_cond_timedwait(cond, abstime) \ __lll_cond_timedwait (cond, abstime) #define lll_cond_wake(cond) \ __lll_cond_wake (cond) #define lll_cond_broadcast(cond) \ __lll_cond_broadcast (cond) #endif /* lowlevellock.h */