1 files changed, 118 insertions, 0 deletions
diff --git a/pthreads/ptw32_semwait.c b/pthreads/ptw32_semwait.c
new file mode 100644
index 000000000..8b23d11d6
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+++ b/pthreads/ptw32_semwait.c
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+/*
+ * ptw32_semwait.c
+ *
+ * Description:
+ * This translation unit implements mutual exclusion (mutex) 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
+ */
+
+#ifndef _UWIN
+//#   include <process.h>
+#endif
+#include "pthread.h"
+#include "implement.h"
+
+
+int
+ptw32_semwait (sem_t * sem)
+     /*
+      * ------------------------------------------------------
+      * DESCRIPTION
+      *      This function waits on a POSIX semaphore. If the
+      *      semaphore value is greater than zero, it decreases
+      *      its value by one. If the semaphore value is zero, then
+      *      the calling thread (or process) is blocked until it can
+      *      successfully decrease the value.
+      *
+      *      Unlike sem_wait(), this routine is non-cancelable.
+      *
+      * RESULTS
+      *              0               successfully decreased semaphore,
+      *              -1              failed, error in errno.
+      * ERRNO
+      *              EINVAL          'sem' is not a valid semaphore,
+      *              ENOSYS          semaphores are not supported,
+      *              EINTR           the function was interrupted by a signal,
+      *              EDEADLK         a deadlock condition was detected.
+      *
+      * ------------------------------------------------------
+      */
+{
+  int result = 0;
+  sem_t s = *sem;
+
+  if (s == NULL)
+    {
+      result = EINVAL;
+    }
+  else
+    {
+      if ((result = pthread_mutex_lock (&s->lock)) == 0)
+        {
+          int v = --s->value;
+
+          (void) pthread_mutex_unlock (&s->lock);
+
+          if (v < 0)
+            {
+              /* Must wait */
+              if (WaitForSingleObject (s->sem, INFINITE) == WAIT_OBJECT_0)
+		{
+#ifdef NEED_SEM
+		  if (pthread_mutex_lock (&s->lock) == 0)
+		    {
+		      if (s->leftToUnblock > 0)
+			{
+			  --s->leftToUnblock;
+			  SetEvent(s->sem);
+			}
+		      (void) pthread_mutex_unlock (&s->lock);
+		    }
+#endif
+		  return 0;
+		}
+            }
+          else
+	    {
+	      return 0;
+	    }
+        }
+    }
+
+  if (result != 0)
+    {
+      errno = result;
+      return -1;
+    }
+
+  return 0;
+
+}				/* ptw32_semwait */