cpp: port queue_signalled

include/villas/queue_signalled.hpp

@@ -0,0 +1,70 @@
+/** Wrapper around queue that uses POSIX CV's for signalling writes.
+ *
+ * @file
+ * @author Georg Martin Reinke <georg.reinke@rwth-aachen.de>
+ * @copyright 2017-2018, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#pragma once
+
+#include <mutex>
+#include <condition_variable>
+#include <queue>
+
+namespace villas {
+
+template<typename T>
+class QueueSignalled {
+
+private:
+	std::queue<T> queue;
+	std::mutex mutex;
+	std::condition_variable cv;
+
+public:
+	void push(const T& data)
+	{
+		std::lock_guard<std::mutex> l(mutex);
+
+		queue.push(data);
+		cv.notify_one();
+	}
+
+	T pop()
+	{
+		std::unique_lock<std::mutex> l(mutex);
+
+		while(queue.empty())
+		  cv.wait(l);
+
+		T res = queue.front();
+		queue.pop();
+
+		return res;
+	}
+
+	bool empty()
+	{
+		std::unique_lock<std::mutex> l(mutex);
+
+		return queue.empty();
+	}
+};
+
+} // namespace villas