Add ThreadedDevice.

CMakeLists.txt

@@ -34,6 +34,7 @@ set(SRC
 	src/devices/NULLDevice.cpp
 	src/devices/ReadDevice.cpp
 	src/devices/SoftwareDevice.cpp
+	src/devices/ThreadedDevice.cpp
 	src/Exception.cpp
 	src/file/File.cpp
 	src/file/FileManager.cpp
@@ -140,6 +141,7 @@ set(PUBLIC_HDR
 	include/devices/NULLDevice.h
 	include/devices/ReadDevice.h
 	include/devices/SoftwareDevice.h
+	include/devices/ThreadedDevice.h
 	include/Exception.h
 	include/file/File.h
 	include/file/FileManager.h

include/devices/SoftwareDevice.h

@@ -255,6 +255,7 @@ class AUD_API SoftwareDevice : public IDevice, public I3DDevice
 	/**
 	 * This function tells the device, to start or pause playback.
 	 * \param playing True if device should playback.
+	 * \note This method is only called when the device is locked.
 	 */
 	virtual void playing(bool playing)=0;
 

include/devices/ThreadedDevice.h

@@ -0,0 +1,95 @@
+/*******************************************************************************
+ * Copyright 2009-2016 Jörg Müller
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+#pragma once
+
+/**
+ * @file ThreadedDevice.h
+ * @ingroup plugin
+ * The ThreadedDevice class.
+ */
+
+#include "devices/SoftwareDevice.h"
+
+#include <thread>
+
+AUD_NAMESPACE_BEGIN
+
+/**
+ * This device extends the SoftwareDevice with code for running mixing in a separate thread.
+ */
+class AUD_PLUGIN_API ThreadedDevice : public SoftwareDevice
+{
+private:
+	/**
+	 * Whether there is currently playback.
+	 */
+	bool m_playing;
+
+	/**
+	 * Whether the current playback should stop.
+	 */
+	bool m_stop;
+
+	/**
+	 * The streaming thread.
+	 */
+	std::thread m_thread;
+
+	/**
+	 * Starts the streaming thread.
+	 */
+	AUD_LOCAL void start();
+
+	/**
+	 * Streaming thread main function.
+	 */
+	AUD_LOCAL virtual void runMixingThread()=0;
+
+	// delete copy constructor and operator=
+	ThreadedDevice(const ThreadedDevice&) = delete;
+	ThreadedDevice& operator=(const ThreadedDevice&) = delete;
+
+protected:
+	virtual void playing(bool playing);
+
+	/**
+	 * Empty default constructor. To setup the device call the function create()
+	 * and to uninitialize call destroy().
+	 */
+	ThreadedDevice();
+
+	/**
+	 * Indicates that the mixing thread should be stopped.
+	 * \return Whether the mixing thread should be stopping.
+	 * \warning For thread safety, the device needs to be locked, when this method is called.
+	 */
+	inline bool shouldStop() { return m_stop; }
+
+	/**
+	 * This method needs to be called when the mixing thread is stopping.
+	 * \warning For thread safety, the device needs to be locked, when this method is called.
+	 */
+	inline void doStop() { m_stop = m_playing = false; }
+
+	/**
+	 * Stops all playback and notifies the mixing thread to stop.
+	 * \warning The device has to be unlocked to not run into a deadlock.
+	 */
+	void stopMixingThread();
+};
+
+AUD_NAMESPACE_END

src/devices/ThreadedDevice.cpp

@@ -0,0 +1,65 @@
+/*******************************************************************************
+ * Copyright 2009-2016 Jörg Müller
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+#include "devices/ThreadedDevice.h"
+
+#include <mutex>
+
+AUD_NAMESPACE_BEGIN
+
+void ThreadedDevice::start()
+{
+	std::lock_guard<ILockable> lock(*this);
+
+	// thread is still running, we can abort stopping it
+	if(m_stop)
+		m_stop = false;
+
+	// thread is not running, let's start it
+	else if(!m_playing)
+	{
+		if(m_thread.joinable())
+			m_thread.join();
+
+		m_playing = true;
+
+		m_thread = std::thread(&ThreadedDevice::runMixingThread, this);
+	}
+}
+
+void ThreadedDevice::playing(bool playing)
+{
+	if((!m_playing || m_stop) && playing)
+		start();
+	else
+		m_stop = true;
+}
+
+ThreadedDevice::ThreadedDevice() :
+	m_playing(false),
+	m_stop(false)
+{
+}
+
+void aud::ThreadedDevice::stopMixingThread()
+{
+	stopAll();
+
+	if(m_thread.joinable())
+		m_thread.join();
+}
+
+AUD_NAMESPACE_END