/* Copyright (C) 2003, 2004 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Martin Schwidefsky , 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 #define SYS_futex 238 #define FUTEX_WAIT 0 #define FUTEX_WAKE 1 #define FUTEX_REQUEUE 3 #define FUTEX_CMP_REQUEUE 4 /* Initializer for compatibility lock. */ #define LLL_MUTEX_LOCK_INITIALIZER (0) #define lll_futex_wait(futex, val) \ ({ \ register unsigned long int __r2 asm ("2") = (unsigned long int) (futex); \ register unsigned long int __r3 asm ("3") = FUTEX_WAIT; \ register unsigned long int __r4 asm ("4") = (unsigned long int) (val); \ register unsigned long int __r5 asm ("5") = 0ul; \ register unsigned long __result asm ("2"); \ \ __asm __volatile ("svc %b1" \ : "=d" (__result) \ : "i" (SYS_futex), "0" (__r2), "d" (__r3), \ "d" (__r4), "d" (__r5) \ : "cc", "memory" ); \ __result; \ }) #define lll_futex_timed_wait(futex, val, timespec) \ ({ \ register unsigned long int __r2 asm ("2") = (unsigned long int) (futex); \ register unsigned long int __r3 asm ("3") = FUTEX_WAIT; \ register unsigned long int __r4 asm ("4") = (unsigned long int) (val); \ register unsigned long int __r5 asm ("5") = (unsigned long int)(timespec);\ register unsigned long int __result asm ("2"); \ \ __asm __volatile ("svc %b1" \ : "=d" (__result) \ : "i" (SYS_futex), "0" (__r2), "d" (__r3), \ "d" (__r4), "d" (__r5) \ : "cc", "memory" ); \ __result; \ }) #define lll_futex_wake(futex, nr) \ ({ \ register unsigned long int __r2 asm ("2") = (unsigned long int) (futex); \ register unsigned long int __r3 asm ("3") = FUTEX_WAKE; \ register unsigned long int __r4 asm ("4") = (unsigned long int) (nr); \ register unsigned long int __result asm ("2"); \ \ __asm __volatile ("svc %b1" \ : "=d" (__result) \ : "i" (SYS_futex), "0" (__r2), "d" (__r3), "d" (__r4) \ : "cc", "memory" ); \ __result; \ }) /* Returns non-zero if error happened, zero if success. */ #define lll_futex_requeue(futex, nr_wake, nr_move, mutex, val) \ ({ \ register unsigned long int __r2 asm ("2") = (unsigned long int) (futex); \ register unsigned long int __r3 asm ("3") = FUTEX_CMP_REQUEUE; \ register unsigned long int __r4 asm ("4") = (long int) (nr_wake); \ register unsigned long int __r5 asm ("5") = (long int) (nr_move); \ register unsigned long int __r6 asm ("6") = (unsigned long int) (mutex); \ register unsigned long int __r7 asm ("7") = (int) (val); \ register unsigned long __result asm ("2"); \ \ __asm __volatile ("svc %b1" \ : "=d" (__result) \ : "i" (SYS_futex), "0" (__r2), "d" (__r3), \ "d" (__r4), "d" (__r5), "d" (__r6), "d" (__r7) \ : "cc", "memory" ); \ __result > -4096UL; \ }) #define lll_compare_and_swap(futex, oldval, newval, operation) \ do { \ __typeof (futex) __futex = (futex); \ __asm __volatile (" l %1,%0\n" \ "0: " operation "\n" \ " cs %1,%2,%0\n" \ " jl 0b\n" \ "1:" \ : "=Q" (*__futex), "=&d" (oldval), "=&d" (newval) \ : "m" (*__futex) : "cc", "memory" ); \ } while (0) static inline int __attribute__ ((always_inline)) __lll_mutex_trylock (int *futex) { unsigned int old; __asm __volatile ("cs %0,%3,%1" : "=d" (old), "=Q" (*futex) : "0" (0), "d" (1), "m" (*futex) : "cc", "memory" ); return old != 0; } #define lll_mutex_trylock(futex) __lll_mutex_trylock (&(futex)) static inline int __attribute__ ((always_inline)) __lll_mutex_cond_trylock (int *futex) { unsigned int old; __asm __volatile ("cs %0,%3,%1" : "=d" (old), "=Q" (*futex) : "0" (0), "d" (2), "m" (*futex) : "cc", "memory" ); return old != 0; } #define lll_mutex_cond_trylock(futex) __lll_mutex_cond_trylock (&(futex)) extern void __lll_lock_wait (int *futex) attribute_hidden; static inline void __attribute__ ((always_inline)) __lll_mutex_lock (int *futex) { if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0) __lll_lock_wait (futex); } #define lll_mutex_lock(futex) __lll_mutex_lock (&(futex)) static inline void __attribute__ ((always_inline)) __lll_mutex_cond_lock (int *futex) { if (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0) __lll_lock_wait (futex); } #define lll_mutex_cond_lock(futex) __lll_mutex_cond_lock (&(futex)) extern int __lll_timedlock_wait (int *futex, const struct timespec *) attribute_hidden; static inline int __attribute__ ((always_inline)) __lll_mutex_timedlock (int *futex, const struct timespec *abstime) { int result = 0; if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0) result = __lll_timedlock_wait (futex, 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 oldval; int newval = 0; lll_compare_and_swap (futex, oldval, newval, "slr %2,%2"); if (oldval > 1) 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) { *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; /* 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) extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; /* The states of a lock are: 1 - untaken 0 - taken by one user <0 - taken by more users */ /* 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. */ static inline void __attribute__ ((always_inline)) __lll_wait_tid (int *ptid) { int tid; while ((tid = *ptid) != 0) lll_futex_wait (ptid, tid); } #define lll_wait_tid(tid) __lll_wait_tid(&(tid)) 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 */