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-rw-r--r--pthreads/pthread_barrier_init.c81
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+/*
+ * pthread_barrier_init.c
+ *
+ * Description:
+ * This translation unit implements barrier 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_barrier_init (pthread_barrier_t * barrier,
+ const pthread_barrierattr_t * attr, unsigned int count)
+{
+ pthread_barrier_t b;
+
+ if (barrier == NULL || count == 0)
+ {
+ return EINVAL;
+ }
+
+ if (NULL != (b = (pthread_barrier_t) calloc (1, sizeof (*b))))
+ {
+ b->pshared = (attr != NULL && *attr != NULL
+ ? (*attr)->pshared : PTHREAD_PROCESS_PRIVATE);
+
+ b->nCurrentBarrierHeight = b->nInitialBarrierHeight = count;
+ b->iStep = 0;
+
+ /*
+ * Two semaphores are used in the same way as two stepping
+ * stones might be used in crossing a stream. Once all
+ * threads are safely on one stone, the other stone can
+ * be moved ahead, and the threads can start moving to it.
+ * If some threads decide to eat their lunch before moving
+ * then the other threads have to wait.
+ */
+ if (0 == sem_init (&(b->semBarrierBreeched[0]), b->pshared, 0))
+ {
+ if (0 == sem_init (&(b->semBarrierBreeched[1]), b->pshared, 0))
+ {
+ *barrier = b;
+ return 0;
+ }
+ (void) sem_destroy (&(b->semBarrierBreeched[0]));
+ }
+ (void) free (b);
+ }
+
+ return ENOMEM;
+}