| /* |
| * pthread_spin_trylock.c |
| * |
| * Description: |
| * This translation unit implements spin lock primitives. |
| * |
| * -------------------------------------------------------------------------- |
| * |
| * Pthreads-win32 - POSIX Threads Library for Win32 |
| * Copyright(C) 1998 John E. Bossom |
| * Copyright(C) 1999,2005 Pthreads-win32 contributors |
| * |
| * Contact Email: rpj@callisto.canberra.edu.au |
| * |
| * 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 |
| */ |
| |
| #include "pthread.h" |
| #include "implement.h" |
| |
| |
| int |
| pthread_spin_trylock (pthread_spinlock_t * lock) |
| { |
| register pthread_spinlock_t s; |
| |
| if (NULL == lock || NULL == *lock) |
| { |
| return (EINVAL); |
| } |
| |
| if (*lock == PTHREAD_SPINLOCK_INITIALIZER) |
| { |
| int result; |
| |
| if ((result = ptw32_spinlock_check_need_init (lock)) != 0) |
| { |
| return (result); |
| } |
| } |
| |
| s = *lock; |
| |
| switch ((long) |
| PTW32_INTERLOCKED_COMPARE_EXCHANGE ((PTW32_INTERLOCKED_LPLONG) & |
| (s->interlock), |
| (PTW32_INTERLOCKED_LONG) |
| PTW32_SPIN_LOCKED, |
| (PTW32_INTERLOCKED_LONG) |
| PTW32_SPIN_UNLOCKED)) |
| { |
| case PTW32_SPIN_UNLOCKED: |
| return 0; |
| case PTW32_SPIN_LOCKED: |
| return EBUSY; |
| case PTW32_SPIN_USE_MUTEX: |
| return pthread_mutex_trylock (&(s->u.mutex)); |
| } |
| |
| return EINVAL; |
| } |