Moved OpenThreads directly into OpenSceneGraph/trunk rather than being introduced via svn:externals.

This change has been done to make it easier for OpenSceneGraph users to check out the svn via https 
without any conflicts introduced with a http externals.

src/OpenThreads/win32/Win32ThreadBarrier.cpp

@@ -0,0 +1,149 @@
+/* -*-c++-*- OpenThreads library, Copyright (C) 2002 - 2007  The Open Thread Group
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * 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 
+ * OpenSceneGraph Public License for more details.
+*/
+
+//
+// Win32Barrier.c++ - C++ Barrier class built on top of POSIX threads.
+// ~~~~~~~~~~~~~~~~~~
+//
+
+#include  <OpenThreads/Barrier>
+#include  <OpenThreads/Thread>
+#include  <OpenThreads/ScopedLock>
+#include "Win32BarrierPrivateData.h"
+using namespace OpenThreads;
+
+// so compiler can place it somewhere
+Win32BarrierPrivateData::~Win32BarrierPrivateData()
+{
+};
+
+//----------------------------------------------------------------------------
+//
+// Description: Constructor
+//
+// Use: public.
+//
+Barrier::Barrier(int numThreads) {
+    Win32BarrierPrivateData *pd = new Win32BarrierPrivateData();
+    pd->cnt = 0;
+    pd->phase = 0;
+    pd->maxcnt = numThreads;
+    _valid = true;
+    _prvData = static_cast<void *>(pd);
+}
+//----------------------------------------------------------------------------
+//
+// Description: Destructor
+//
+// Use: public.
+//
+Barrier::~Barrier() {
+    Win32BarrierPrivateData *pd =
+        static_cast<Win32BarrierPrivateData*>(_prvData);
+    delete pd;
+}
+//----------------------------------------------------------------------------
+//
+// Description: Reset the barrier to its original state
+//
+// Use: public.
+//
+void Barrier::reset() {
+    Win32BarrierPrivateData *pd =
+        static_cast<Win32BarrierPrivateData*>(_prvData);
+    pd->cnt = 0;
+    pd->phase = 0;
+}
+//----------------------------------------------------------------------------
+//
+// Description: Block until numThreads threads have entered the barrier.
+//
+// Use: public.
+//
+void Barrier::block(unsigned int numThreads) {
+
+    Win32BarrierPrivateData *pd =
+        static_cast<Win32BarrierPrivateData*>(_prvData);
+
+    if(numThreads != 0) pd->maxcnt = numThreads;
+    int my_phase;
+
+    ScopedLock<Mutex> lock(pd->lock);
+    if( _valid )
+    {
+        my_phase = pd->phase;
+        ++pd->cnt;
+
+        if (pd->cnt == pd->maxcnt) {             // I am the last one
+            pd->cnt = 0;                         // reset for next use
+            pd->phase = 1 - my_phase;            // toggle phase
+            pd->cond.broadcast();
+        }else{ 
+            while (pd->phase == my_phase ) {
+                pd->cond.wait(&pd->lock);
+            }
+        }
+    }
+}
+
+void Barrier::invalidate()
+{
+    Win32BarrierPrivateData *pd =
+            static_cast<Win32BarrierPrivateData*>(_prvData);
+
+    pd->lock.lock();
+    _valid = false;
+    pd->lock.unlock();
+    release();
+}
+
+
+//----------------------------------------------------------------------------
+//
+// Description: Release the barrier, now.
+//
+// Use: public.
+//
+void Barrier::release() {
+
+    Win32BarrierPrivateData *pd =
+        static_cast<Win32BarrierPrivateData*>(_prvData);
+
+    int my_phase;
+
+    ScopedLock<Mutex> lock(pd->lock);
+    my_phase = pd->phase;
+    
+    pd->cnt = 0;                         // reset for next use
+    pd->phase = 1 - my_phase;            // toggle phase
+    pd->cond.broadcast();
+    
+}
+
+//----------------------------------------------------------------------------
+//
+// Description: Return the number of threads currently blocked in the barrier
+//
+// Use: public
+//
+int Barrier::numThreadsCurrentlyBlocked() {
+    
+    Win32BarrierPrivateData *pd =
+        static_cast<Win32BarrierPrivateData*>(_prvData);
+
+    int numBlocked = -1;
+    ScopedLock<Mutex> lock(pd->lock);
+    numBlocked = pd->cnt;
+    return numBlocked;
+
+}