diff options
Diffstat (limited to 'libs/pthreads/src/pthread_spin_destroy.c')
-rw-r--r-- | libs/pthreads/src/pthread_spin_destroy.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/libs/pthreads/src/pthread_spin_destroy.c b/libs/pthreads/src/pthread_spin_destroy.c new file mode 100644 index 0000000000..786c4e34cd --- /dev/null +++ b/libs/pthreads/src/pthread_spin_destroy.c @@ -0,0 +1,111 @@ +/* + * 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) 1999,2005 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_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); +} |