Add threaded barrier operation modeled after that of boost.

Core/src/Thread.cpp

@@ -38,3 +38,67 @@ void TCThreadBase::CheckReferenceCount() {
   assert(m_Impl->GetReferenceCount() > 0);
 }
 #endif
+
+////////////////////////////////////////////////////////////////////////////////
+//
+// Barrier Implementation
+//
+////////////////////////////////////////////////////////////////////////////////
+
+class TCBarrierImpl : public TCThreadBaseImpl {
+private:
+  unsigned int m_ThreadLimit;
+  unsigned int m_ThreadCount;
+  unsigned int m_Times;
+  
+  TCMutex m_Mutex;
+  TCConditionVariable m_CV;
+
+public:
+  TCBarrierImpl(int threads) 
+    : TCThreadBaseImpl()
+    , m_ThreadCount(threads)
+    , m_ThreadLimit(threads)
+    , m_Times(0) 
+  { 
+    assert(threads > 0);
+  }
+
+  virtual ~TCBarrierImpl() { }
+  
+  bool Wait() {
+    TCLock lock(m_Mutex);
+    unsigned int times = m_Times;
+
+    if(--m_ThreadCount == 0) {
+      m_Times = 0;
+      m_ThreadCount = m_ThreadLimit;
+      m_CV.NotifyAll();
+      return true;
+    }
+
+    while(times == m_Times) {
+      m_CV.Wait(lock);
+    }
+    return false;
+  }
+};
+
+class TCBarrierImplFactory : public TCThreadBaseImplFactory {
+private:
+  int m_NumThreads;
+public:
+  TCBarrierImplFactory(int threads) : TCThreadBaseImplFactory(), m_NumThreads(threads) { }
+  virtual ~TCBarrierImplFactory() { }
+  virtual TCThreadBaseImpl *CreateImpl() const {
+    return new TCBarrierImpl(m_NumThreads);
+  }
+};
+
+TCBarrier::TCBarrier(int threads) 
+  : TCThreadBase(TCBarrierImplFactory(threads)) 
+{ }
+
+void TCBarrier::Wait() {
+  ((TCBarrierImpl *)m_Impl)->Wait();
+}

Core/src/Thread.h

@@ -111,4 +111,16 @@ class TCConditionVariable : public TCThreadBase {
   void NotifyAll();
 };
 
+////////////////////////////////////////////////////////////////////////////////
+//
+// Barrier implementation
+//
+////////////////////////////////////////////////////////////////////////////////
+
+class TCBarrier : public TCThreadBase {
+ public:
+  TCBarrier(int threads);
+  void Wait();
+};
+
 #endif //__TEX_COMP_THREAD_H__