Imported Upstream version 0.13.2+dsfg1

deps/w32-pthreads/pthread_rwlock_destroy.c

@@ -0,0 +1,143 @@
+/*
+ * pthread_rwlock_destroy.c
+ *
+ * Description:
+ * This translation unit implements read/write 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.,
+ *      51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <limits.h>
+
+#include "pthread.h"
+#include "implement.h"
+
+int
+pthread_rwlock_destroy (pthread_rwlock_t * rwlock)
+{
+  pthread_rwlock_t rwl;
+  int result = 0, result1 = 0, result2 = 0;
+
+  if (rwlock == NULL || *rwlock == NULL)
+    {
+      return EINVAL;
+    }
+
+  if (*rwlock != PTHREAD_RWLOCK_INITIALIZER)
+    {
+      rwl = *rwlock;
+
+      if (rwl->nMagic != PTW32_RWLOCK_MAGIC)
+	{
+	  return EINVAL;
+	}
+
+      if ((result = pthread_mutex_lock (&(rwl->mtxExclusiveAccess))) != 0)
+	{
+	  return result;
+	}
+
+      if ((result =
+	   pthread_mutex_lock (&(rwl->mtxSharedAccessCompleted))) != 0)
+	{
+	  (void) pthread_mutex_unlock (&(rwl->mtxExclusiveAccess));
+	  return result;
+	}
+
+      /*
+       * Check whether any threads own/wait for the lock (wait for ex.access);
+       * report "BUSY" if so.
+       */
+      if (rwl->nExclusiveAccessCount > 0
+	  || rwl->nSharedAccessCount > rwl->nCompletedSharedAccessCount)
+	{
+	  result = pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted));
+	  result1 = pthread_mutex_unlock (&(rwl->mtxExclusiveAccess));
+	  result2 = EBUSY;
+	}
+      else
+	{
+	  rwl->nMagic = 0;
+
+	  if ((result =
+	       pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted))) != 0)
+	    {
+	      pthread_mutex_unlock (&rwl->mtxExclusiveAccess);
+	      return result;
+	    }
+
+	  if ((result =
+	       pthread_mutex_unlock (&(rwl->mtxExclusiveAccess))) != 0)
+	    {
+	      return result;
+	    }
+
+	  *rwlock = NULL;	/* Invalidate rwlock before anything else */
+	  result = pthread_cond_destroy (&(rwl->cndSharedAccessCompleted));
+	  result1 = pthread_mutex_destroy (&(rwl->mtxSharedAccessCompleted));
+	  result2 = pthread_mutex_destroy (&(rwl->mtxExclusiveAccess));
+	  (void) free (rwl);
+	}
+    }
+  else
+    {
+      ptw32_mcs_local_node_t node;
+      /*
+       * See notes in ptw32_rwlock_check_need_init() above also.
+       */
+      ptw32_mcs_lock_acquire(&ptw32_rwlock_test_init_lock, &node);
+
+      /*
+       * Check again.
+       */
+      if (*rwlock == PTHREAD_RWLOCK_INITIALIZER)
+	{
+	  /*
+	   * This is all we need to do to destroy a statically
+	   * initialised rwlock that has not yet been used (initialised).
+	   * If we get to here, another thread
+	   * waiting to initialise this rwlock will get an EINVAL.
+	   */
+	  *rwlock = NULL;
+	}
+      else
+	{
+	  /*
+	   * The rwlock has been initialised while we were waiting
+	   * so assume it's in use.
+	   */
+	  result = EBUSY;
+	}
+
+      ptw32_mcs_lock_release(&node);
+    }
+
+  return ((result != 0) ? result : ((result1 != 0) ? result1 : result2));
+}