/* * pthread_spin_destroy.c * * Description: * This translation unit implements spin lock primitives. * * -------------------------------------------------------------------------- * * Pthreads-win32 - POSIX Threads Library for Win32 * Copyright(C) 1998 John E. Bossom * Copyright(C) 1999,2012 Pthreads-win32 contributors * * Homepage1: http://sourceware.org/pthreads-win32/ * Homepage2: http://sourceforge.net/projects/pthreads4w/ * * The current list of contributors is contained * in the file CONTRIBUTORS included with the source * code distribution. The list can also be seen at the * following World Wide Web location: * http://sources.redhat.com/pthreads-win32/contributors.html * * This 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 of the License, or (at your option) any later version. * * This 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 this library in the file COPYING.LIB; * if not, write to the Free Software Foundation, Inc., * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ #ifdef HAVE_CONFIG_H # include <config.h> #endif #include "pthread.h" #include "implement.h" int pthread_spin_destroy (pthread_spinlock_t * lock) { register pthread_spinlock_t s; int result = 0; if (lock == NULL || *lock == NULL) { return EINVAL; } if ((s = *lock) != PTHREAD_SPINLOCK_INITIALIZER) { if (s->interlock == PTW32_SPIN_USE_MUTEX) { result = pthread_mutex_destroy (&(s->u.mutex)); } else if ((PTW32_INTERLOCKED_LONG) PTW32_SPIN_UNLOCKED != PTW32_INTERLOCKED_COMPARE_EXCHANGE_LONG ((PTW32_INTERLOCKED_LONGPTR) &s->interlock, (PTW32_INTERLOCKED_LONG) PTW32_SPIN_INVALID, (PTW32_INTERLOCKED_LONG) PTW32_SPIN_UNLOCKED)) { result = EINVAL; } if (0 == result) { /* * We are relying on the application to ensure that all other threads * have finished with the spinlock before destroying it. */ *lock = NULL; (void) free (s); } } else { /* * See notes in ptw32_spinlock_check_need_init() above also. */ ptw32_mcs_local_node_t node; ptw32_mcs_lock_acquire(&ptw32_spinlock_test_init_lock, &node); /* * Check again. */ if (*lock == PTHREAD_SPINLOCK_INITIALIZER) { /* * This is all we need to do to destroy a statically * initialised spinlock that has not yet been used (initialised). * If we get to here, another thread * waiting to initialise this mutex will get an EINVAL. */ *lock = NULL; } else { /* * The spinlock has been initialised while we were waiting * so assume it's in use. */ result = EBUSY; } ptw32_mcs_lock_release(&node); } return (result); }