Moved more stuff to orkbasecxx

git-svn-id: https://oreka.svn.sourceforge.net/svnroot/oreka/trunk@287 09dcff7a-b715-0410-9601-b79a96267cd0

1 files changed, 97 insertions, 0 deletions

diff --git a/orkbasecxx/ThreadSafeQueue.h b/orkbasecxx/ThreadSafeQueue.h
new file mode 100644
index 0000000..4fd0cda
--- /dev/null
+++ b/orkbasecxx/ThreadSafeQueue.h
@@ -0,0 +1,97 @@
+/*
+ * Oreka -- A media capture and retrieval platform
+ * 
+ * Copyright (C) 2005, orecx LLC
+ *
+ * http://www.orecx.com
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License.
+ * Please refer to http://www.gnu.org/copyleft/gpl.html
+ *
+ */
+
+#ifndef __THREADSAFEQUEUE_H__
+#define __THREADSAFEQUEUE_H__
+
+#include <queue>
+#include "ace/Thread_Mutex.h"
+#include "ace/Thread_Semaphore.h"
+#include "Utils.h"
+
+/** Thread safe queue holding objects of arbitrary class.
+	Enqueuing is never blocking
+	Dequeuing is blocking when the queue is empty
+ */
+template <class T> class ThreadSafeQueue
+{
+public:
+	ThreadSafeQueue(int size = 10000)
+	{
+		m_size = size;
+		m_semaphore.acquire(); // reset count to zero
+	};
+
+	bool push(T &);
+	T pop();
+	int numElements();
+	void setSize(int size);
+
+private:
+	int m_size;
+	ACE_Thread_Mutex m_mutex;
+	ACE_Thread_Semaphore m_semaphore;
+	std::queue<T> m_queue;
+};
+
+
+/** Push an element onto the queue, returns false if queue full (never blocks) */
+template <class T> bool ThreadSafeQueue<T>::push(T &element)
+{
+	bool result = false;
+	MutexSentinel mutexSentinel(m_mutex);
+
+	if (m_queue.size() < (unsigned int)m_size)
+	{
+		m_queue.push(element);
+		result = true;
+	}
+
+	m_semaphore.release();
+	return result;
+}
+
+/** Pop and element from the queue, or blocks until one available */
+template <class T> T ThreadSafeQueue<T>::pop()
+{
+// #### Fixme: when timeout specified under Linux CentOS 4.2, acquire returns immediately instead of waiting for the timeout -> causes CPU to spike at 100% 
+#ifdef WIN32
+	ACE_Time_Value timeout(time(NULL)+2);
+	m_semaphore.acquire(&timeout);
+#else
+        m_semaphore.acquire();
+#endif
+	MutexSentinel mutexSentinel(m_mutex);
+
+	T element;
+
+	if(m_queue.size() > 0)
+	{
+		element = m_queue.front();
+		m_queue.pop();
+	}
+	return element;
+}
+
+template <class T> int ThreadSafeQueue<T>::numElements()
+{
+	return m_queue.size();
+}
+
+template <class T> void ThreadSafeQueue<T>::setSize(int size)
+{
+	m_size = size;
+}
+
+#endif // __THREADSAFEQUEUE_H__
+