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Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/alpha/lowlevellock.h')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/alpha/lowlevellock.h | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/alpha/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/alpha/lowlevellock.h new file mode 100644 index 0000000000..e286ef36cb --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/alpha/lowlevellock.h @@ -0,0 +1,218 @@ +/* Copyright (C) 2003 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 Libr \ary; 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 <time.h> +#include <sys/param.h> +#include <bits/pthreadtypes.h> +#include <atomic.h> + + +#define __NR_futex 394 +#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_wait(futexp, val) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 4, \ + (futexp), FUTEX_WAIT, (val), 0); \ + INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret: 0; \ + }) + +#define lll_futex_timed_wait(futexp, val, timespec) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 4, \ + (futexp), FUTEX_WAIT, (val), (timespec)); \ + INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret: 0; \ + }) + +#define lll_futex_wake(futexp, nr) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 4, \ + (futexp), FUTEX_WAKE, (nr), 0); \ + INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret: 0; \ + }) + +#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + \ + __ret = INTERNAL_SYSCALL (futex, __err, 5, \ + (futexp), FUTEX_REQUEUE, (nr_wake), (nr_move), \ + (mutex)); \ + INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret: 0; \ + }) + +/* Set *futex to 1 if it is 0, atomically. Returns the old value */ +#define __lll_trylock(futex) \ + ({ int __oldval, __temp; \ + __asm __volatile ( \ + "1: ldl_l %[__oldval], %[__mem]\n" \ + " lda %[__temp], 1\n" \ + " bne %[__oldval], 2f\n" \ + " stl_c %[__temp], %[__mem]\n" \ + " beq %[__temp], 1b\n" \ + __MB \ + "2:" \ + : [__oldval] "=&r" (__oldval), \ + [__temp] "=&r" (__temp) \ + : [__mem] "m" (*(futex)) \ + : "memory"); \ + __oldval; \ + }) + +#define lll_mutex_trylock(lock) __lll_trylock (&(lock)) + + +extern void __lll_lock_wait (int *futex, int val) attribute_hidden; + +#define lll_mutex_lock(lock) \ + (void) ({ \ + int *__futex = &(lock); \ + int __val = atomic_exchange_and_add (__futex, 1); \ + atomic_full_barrier(); \ + if (__builtin_expect (__val != 0, 0)) \ + __lll_lock_wait (__futex, __val); \ + }) + +#define lll_mutex_cond_lock(lock) \ + (void) ({ \ + int *__futex = &(lock); \ + int __val = atomic_exchange_and_add (__futex, 2); \ + atomic_full_barrier(); \ + 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); \ + }) + +extern int __lll_timedlock_wait + (int *futex, int val, const struct timespec *) attribute_hidden; + +#define lll_mutex_timedlock(lock, abstime) \ + ({ int *__futex = &(lock); \ + int __val = atomic_exchange_and_add (__futex, 1); \ + atomic_full_barrier(); \ + if (__builtin_expect (__val != 0, 0)) \ + __val = __lll_timedlock_wait (__futex, __val, (abstime)); \ + __val; \ + }) + +#define lll_mutex_unlock(lock) \ + ((void) ({ \ + int *__futex = &(lock), __val; \ + atomic_write_barrier(); \ + __val = atomic_exchange_rel (__futex, 0); \ + if (__builtin_expect (__val > 1, 0)) \ + lll_futex_wake (__futex, 1); \ + })) + +#define lll_mutex_unlock_force(lock) \ + ((void) ({ \ + int *__futex = &(lock); \ + atomic_write_barrier(); \ + *__futex = 0; \ + atomic_full_barrier(); \ + lll_futex_wake (__futex, 1); \ + })) + +#define lll_mutex_islocked(futex) \ + (futex != 0) + + +/* Our internal lock implementation is identical to the binary-compatible + mutex implementation. */ + +/* Type for lock object. */ +typedef int lll_lock_t; + +/* Initializers for lock. */ +#define LLL_LOCK_INITIALIZER (0) +#define LLL_LOCK_INITIALIZER_LOCKED (1) + +extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; + +/* The states of a lock are: + 0 - untaken + 1 - taken by one user + >1 - taken by more users */ + +#define lll_trylock(lock) lll_mutex_trylock (lock) +#define lll_lock(lock) lll_mutex_lock (lock) +#define lll_unlock(lock) lll_mutex_unlock (lock) +#define lll_islocked(lock) lll_mutex_islocked (lock) + +/* The kernel notifies a process which 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 */ |