/* Spin locks. Copyright (C) 2000, 2004 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 Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library 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 #include /* The default for single processor machines; don't spin, it's pointless. */ #ifndef __PTHREAD_SPIN_COUNT # define __PTHREAD_SPIN_COUNT 1 #endif /* The number of times to spin while trying to lock a spin lock object before yielding the processor. */ int __pthread_spin_count = __PTHREAD_SPIN_COUNT; /* Lock the spin lock object LOCK. If the lock is held by another thread spin until it becomes available. */ int _pthread_spin_lock (__pthread_spinlock_t *lock) { int i; while (1) { for (i = 0; i < __pthread_spin_count; i++) { if (__pthread_spin_trylock (lock) == 0) return 0; } __sched_yield (); } } weak_alias (_pthread_spin_lock, pthread_spin_lock); weak_alias (_pthread_spin_lock, __pthread_spin_lock);