/* POSIX spinlock implementation. Arm version. Copyright (C) 2000 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; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <errno.h> #include <pthread.h> #include "internals.h" int __pthread_spin_lock (pthread_spinlock_t *lock) { unsigned int val; do __asm__ __volatile__ ("swp %0, %1, [%2]" : "=r" (val) : "0" (1), "r" (lock) : "memory"); while (val != 0); return 0; } weak_alias (__pthread_spin_lock, pthread_spin_lock) int __pthread_spin_trylock (pthread_spinlock_t *lock) { unsigned int val; __asm__ __volatile__ ("swp %0, %1, [%2]" : "=r" (val) : "0" (1), "r" (lock) : "memory"); return val ? EBUSY : 0; } weak_alias (__pthread_spin_trylock, pthread_spin_trylock) int __pthread_spin_unlock (pthread_spinlock_t *lock) { return *lock = 0; } weak_alias (__pthread_spin_unlock, pthread_spin_unlock) int __pthread_spin_init (pthread_spinlock_t *lock, int pshared) { /* We can ignore the `pshared' parameter. Since we are busy-waiting all processes which can access the memory location `lock' points to can use the spinlock. */ return *lock = 0; } weak_alias (__pthread_spin_init, pthread_spin_init) int __pthread_spin_destroy (pthread_spinlock_t *lock) { /* Nothing to do. */ return 0; } weak_alias (__pthread_spin_destroy, pthread_spin_destroy)