/*
* 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: [email protected]
*
* 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_LONG ((PTW32_INTERLOCKED_LONGPTR) &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;
}