From 2ab3d99967d68c79351fe2a3df22c445447e3010 Mon Sep 17 00:00:00 2001
From: Michał Cichoń <michcic@gmail.com>
Date: Tue, 15 Nov 2011 22:28:48 +0100
Subject: Initial import.

---
 pthreads/src/sem_destroy.c | 144 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 144 insertions(+)
 create mode 100644 pthreads/src/sem_destroy.c

(limited to 'pthreads/src/sem_destroy.c')

diff --git a/pthreads/src/sem_destroy.c b/pthreads/src/sem_destroy.c
new file mode 100644
index 0000000..6c98e80
--- /dev/null
+++ b/pthreads/src/sem_destroy.c
@@ -0,0 +1,144 @@
+/*
+ * -------------------------------------------------------------
+ *
+ * Module: sem_destroy.c
+ *
+ * Purpose:
+ *	Semaphores aren't actually part of the PThreads standard.
+ *	They are defined by the POSIX Standard:
+ *
+ *		POSIX 1003.1b-1993	(POSIX.1b)
+ *
+ * -------------------------------------------------------------
+ *
+ * --------------------------------------------------------------------------
+ *
+ *      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 "semaphore.h"
+#include "implement.h"
+
+
+int
+sem_destroy (sem_t * sem)
+     /*
+      * ------------------------------------------------------
+      * DOCPUBLIC
+      *      This function destroys an unnamed semaphore.
+      *
+      * PARAMETERS
+      *      sem
+      *              pointer to an instance of sem_t
+      *
+      * DESCRIPTION
+      *      This function destroys an unnamed semaphore.
+      *
+      * RESULTS
+      *              0               successfully destroyed semaphore,
+      *              -1              failed, error in errno
+      * ERRNO
+      *              EINVAL          'sem' is not a valid semaphore,
+      *              ENOSYS          semaphores are not supported,
+      *              EBUSY           threads (or processes) are currently
+      *                                      blocked on 'sem'
+      *
+      * ------------------------------------------------------
+      */
+{
+  int result = 0;
+  sem_t s = NULL;
+
+  if (sem == NULL || *sem == NULL)
+    {
+      result = EINVAL;
+    }
+  else
+    {
+      s = *sem;
+
+      if ((result = pthread_mutex_lock (&s->lock)) == 0)
+        {
+          if (s->value < 0)
+            {
+              (void) pthread_mutex_unlock (&s->lock);
+              result = EBUSY;
+            }
+          else
+            {
+              /* There are no threads currently blocked on this semaphore. */
+
+              if (!CloseHandle (s->sem))
+	        {
+                  (void) pthread_mutex_unlock (&s->lock);
+	          result = EINVAL;
+	        }
+	      else
+	        {
+                  /*
+                   * Invalidate the semaphore handle when we have the lock.
+                   * Other sema operations should test this after acquiring the lock
+                   * to check that the sema is still valid, i.e. before performing any
+                   * operations. This may only be necessary before the sema op routine
+                   * returns so that the routine can return EINVAL - e.g. if setting
+                   * s->value to SEM_VALUE_MAX below does force a fall-through.
+                   */
+                  *sem = NULL;
+
+                  /* Prevent anyone else actually waiting on or posting this sema.
+                   */
+                  s->value = SEM_VALUE_MAX;
+
+                  (void) pthread_mutex_unlock (&s->lock);
+
+                  do
+                    {
+                      /* Give other threads a chance to run and exit any sema op
+                       * routines. Due to the SEM_VALUE_MAX value, if sem_post or
+                       * sem_wait were blocked by us they should fall through.
+                       */
+                      Sleep(0);
+                    }
+                  while (pthread_mutex_destroy (&s->lock) == EBUSY);
+                }
+            }
+        }
+    }
+
+  if (result != 0)
+    {
+      errno = result;
+      return -1;
+    }
+
+  free (s);
+
+  return 0;
+
+}				/* sem_destroy */
-- 
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