Resolves Audio issues (underwater/overlapping audio buffers).

Redesigned audio manager handling of audio outputs to ensure that only
one channel's audio can be routed to an audio output at a time.

Changed audio outputs to use the shared thread pool manager for
scheduled tasks, instead of creating a thread pool for each audio
output.

src/audio/AudioManager.java

@@ -2,7 +2,7 @@ package audio;
 
 /*******************************************************************************
  *     SDR Trunk 
- *     Copyright (C) 2014,2015 Dennis Sheirer
+ *     Copyright (C) 2014-2016 Dennis Sheirer
  * 
  *     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
@@ -19,14 +19,11 @@ package audio;
  ******************************************************************************/
 
 import java.util.ArrayList;
-
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.concurrent.LinkedTransferQueue;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
@@ -53,7 +50,6 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 	private static final Logger mLog = LoggerFactory.getLogger( AudioManager.class );
 
 	public static final int AUDIO_TIMEOUT = 2000; //2 seconds
-	public static final int NO_SOURCE = 0;
 	
 	public static final AudioEvent CONFIGURATION_CHANGE_STARTED = 
 			new AudioEvent( Type.AUDIO_CONFIGURATION_CHANGE_STARTED, null );
@@ -62,19 +58,19 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 			new AudioEvent( Type.AUDIO_CONFIGURATION_CHANGE_COMPLETE, null );
 
 	private LinkedTransferQueue<AudioPacket> mAudioPacketQueue = new LinkedTransferQueue<>();
-	private Map<Integer,AudioChannelAssignment> mChannelAssignments = new HashMap<>();
+	private Map<Integer,AudioOutputConnection> mChannelConnectionMap = new HashMap<>();
-	private int mLowestPrioritySource;
+	private List<AudioOutputConnection> mAudioOutputConnections = new ArrayList<>();
+	private AudioOutputConnection mLowestPriorityConnection;
+	private int mAvailableConnectionCount;
 
-	private List<AudioOutput> mAvailableAudioOutputs = new ArrayList<>();
 	private Map<String,AudioOutput> mAudioOutputMap = new HashMap<>();
-	private List<String> mChannelNames = new ArrayList<>();
 	
 	private Broadcaster<AudioEvent> mControllerBroadcaster = new Broadcaster<>();
 	
 	private ThreadPoolManager mThreadPoolManager;
 	private ScheduledFuture<?> mProcessingTask;
 	
-	private MixerChannelConfiguration mMixerChannel;
+	private MixerChannelConfiguration mMixerChannelConfiguration;
 
 	/**
 	 * Processes all audio produced by the decoding channels and routes audio 
@@ -92,11 +88,11 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 		
 		if( mixer != null )
 		{
-			mMixerChannel = new MixerChannelConfiguration( mixer, MixerChannel.MONO );
+			mMixerChannelConfiguration = new MixerChannelConfiguration( mixer, MixerChannel.MONO );
 			
 			try
 			{
-				setMixerChannelConfiguration( mMixerChannel );
+				setMixerChannelConfiguration( mMixerChannelConfiguration );
 			} 
 			catch ( AudioException e )
 			{
@@ -116,6 +112,15 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 		
 		mThreadPoolManager = null;
 		mProcessingTask = null;
+
+		mChannelConnectionMap.clear();
+		
+		for( AudioOutputConnection connection: mAudioOutputConnections )
+		{
+			connection.dispose();
+		}
+		
+		mAudioOutputConnections.clear();
 	}
 
 	@Override
@@ -124,210 +129,47 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 		mAudioPacketQueue.add( packet );
 	}
 	
-	public class AudioPacketProcessor implements Runnable
-	{
-		@Override
-		public void run()
-		{
-			removeCompletedChannelAssignments();
-			
-			if( mAudioPacketQueue != null )
-			{
-				List<AudioPacket> packets = new ArrayList<AudioPacket>();
-
-				mAudioPacketQueue.drainTo( packets );
-				
-				for( AudioPacket packet: packets )
-				{
-					/* Don't process any packet's marked as do not monitor */
-					if( !packet.getAudioMetadata().isDoNotMonitor() )
-					{
-						int source = packet.getAudioMetadata().getSource();
-
-						if( packet.getType() != AudioPacket.Type.END )
-						{
-							/* Existing channel assignment */
-							if( mChannelAssignments.containsKey( source ) )
-							{
-								mChannelAssignments.get( source ).getAudioOutput()
-											.receive( packet );
-							}
-							/* Start a new channel assignment */
-							else if( !mAvailableAudioOutputs.isEmpty() )
-							{
-								AudioOutput channel = mAvailableAudioOutputs.remove( 0 );
-								
-								mChannelAssignments.put( packet.getAudioMetadata().getSource(), 
-									new AudioChannelAssignment( channel, packet.getAudioMetadata().getPriority() ) );
-								
-								updateLowestPriorityAssignment();
-								
-								channel.receive( packet );
-							}
-							/* Override the lowest priority assignment */
-							else
-							{
-								if( mLowestPrioritySource > -1 )
-								{
-									int priority = packet.getAudioMetadata().getPriority();
-
-									if( packet.getAudioMetadata().isSelected() || 
-										priority < mChannelAssignments
-											.get( mLowestPrioritySource ).getPriority() )
-									{
-										AudioChannelAssignment assignment = 
-											mChannelAssignments.remove( mLowestPrioritySource );
-										
-										if( assignment != null )
-										{
-											assignment.setPriority( priority );
-
-											int overrideSource = packet.getAudioMetadata().getSource();
-											
-											mChannelAssignments.put( overrideSource, assignment );
-											
-											mLowestPrioritySource = overrideSource;
-											
-											assignment.getAudioOutput().receive( packet );
-										}
-										else
-										{
-											mLowestPrioritySource = -1;
-										}
-									}
-								}
-							}
-						}
-					}
-				}
-			}
-		}
-	}
-	
 	/**
-	 * Checks each audio channel assignment and removes any completed channels.
+	 * Checks each audio channel assignment and disconnects any inactive connections
 	 */
-	private void removeCompletedChannelAssignments()
+	private void disconnectInactiveChannelAssignments()
 	{
-		if( !mChannelAssignments.isEmpty() )
+		boolean changed = false;
+		
+		for( AudioOutputConnection connection: mAudioOutputConnections )
 		{
-			Iterator<Entry<Integer,AudioChannelAssignment>> it = 
+			if( connection.isConnected() && connection.isInactive() )
-					mChannelAssignments.entrySet().iterator();
-
-			Entry<Integer,AudioChannelAssignment> entry;
-
-			boolean removed = false;
-			
-			while( it.hasNext() )
 			{
-				entry = it.next();
+				mChannelConnectionMap.remove( connection.getSource() );
-				
+				connection.disconnect();
-				if( entry.getValue().isComplete() )
+				changed = true;
-				{
-					mAvailableAudioOutputs.add( entry.getValue().getAudioOutput() );
-					entry.getValue().dispose();
-					it.remove();
-					removed = true;
 			}
 		}
 		
-			if( removed )
+		if( changed )
 		{
 			updateLowestPriorityAssignment();
 		}
 	}
-	}
 
 	/**
-	 * Identifies the lowest priority channel assignment ... the one that can
+	 * Identifies the lowest priority channel connection
-	 * be overridden with a higher priority call
 	 */
 	private void updateLowestPriorityAssignment()
 	{
-		int lowestPriority = -1;
+		mLowestPriorityConnection = null;
 		
-		mLowestPrioritySource = -1;
+		for( AudioOutputConnection connection: mAudioOutputConnections )
-		
-		for( int source: mChannelAssignments.keySet() )
 		{
-			AudioChannelAssignment assignment = mChannelAssignments.get( source );
+			if( connection.isConnected() && 
-			
+				( mLowestPriorityConnection == null ||
-			if( assignment.getPriority() > lowestPriority )
+				  mLowestPriorityConnection.getPriority() > connection.getPriority() ) )
 			{
-				lowestPriority = assignment.getPriority();
+				mLowestPriorityConnection = connection;
-				
-				mLowestPrioritySource = source;
 			}
 		}
 	}
 	
-	public void endAllAudioAssignments()
-	{
-		for( AudioOutput output: mAudioOutputMap.values() )
-		{
-			output.receive( new AudioPacket( AudioPacket.Type.END, null ) );
-		}
-	}
-	
-	public class AudioChannelAssignment implements Listener<AudioEvent>
-	{
-		private static final long CALL_END_DELAY = 2000; //2 seconds
-		
-		private AudioOutput mAudioOutput;
-		private int mPriority;
-		private long mAudioStoppedTime = System.currentTimeMillis();
-		
-		public AudioChannelAssignment( AudioOutput audioOutput, int priority )
-		{
-			mAudioOutput = audioOutput;
-			mPriority = priority;
-
-			mAudioOutput.addAudioEventListener( this );
-		}
-		
-		public boolean isComplete()
-		{
-			return mAudioStoppedTime != Long.MAX_VALUE &&
-				   mAudioStoppedTime + CALL_END_DELAY < System.currentTimeMillis();
-		}
-		
-		public void dispose()
-		{
-			mAudioOutput.removeAudioEventListener( this );
-			mAudioOutput.reset();
-			mAudioOutput = null;
-		}
-		
-		public AudioOutput getAudioOutput()
-		{
-			return mAudioOutput;
-		}
-
-		public int getPriority()
-		{
-			return mPriority;
-		}
-		
-		public void setPriority( int priority )
-		{
-			mPriority = priority;
-		}
-
-		@Override
-		public void receive( AudioEvent event )
-		{
-			switch( event.getType() )
-			{
-				case AUDIO_STARTED:
-				case AUDIO_STOPPED:
-				case AUDIO_CONTINUATION:
-					mAudioStoppedTime = System.currentTimeMillis();
-					break;
-				default:
-					break;
-			}
-		}
-	}
 	
 	@Override
 	public void setMixerChannelConfiguration( MixerChannelConfiguration entry ) throws AudioException
@@ -343,40 +185,28 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 				mThreadPoolManager.cancel( mProcessingTask );
 			}
 			
-			endAllAudioAssignments();
+			disposeCurrentConfiguration();
-			
-			for( Entry<Integer,AudioChannelAssignment> e: mChannelAssignments.entrySet() )
-			{
-				e.getValue().getAudioOutput().dispose();
-			}
-			mChannelAssignments.clear();
-			
-			for( AudioOutput output: mAvailableAudioOutputs )
-			{
-				output.dispose();
-			}
-			mAvailableAudioOutputs.clear();
-
-			mChannelNames.clear();
-			mAudioOutputMap.clear();
 			
 			switch( entry.getMixerChannel() )
 			{
 				case MONO:
-					AudioOutput mono = new MonoAudioOutput( entry.getMixer() );
+					AudioOutput mono = new MonoAudioOutput( mThreadPoolManager,
-					mAvailableAudioOutputs.add( mono );
+							entry.getMixer() );
-					mChannelNames.add( mono.getChannelName() );
+					mAudioOutputConnections.add( new AudioOutputConnection( mono ) );
+					mAvailableConnectionCount++;
 					mAudioOutputMap.put( mono.getChannelName(), mono );
 					break;
 				case STEREO:
-					AudioOutput left = new StereoAudioOutput( entry.getMixer(), MixerChannel.LEFT );
+					AudioOutput left = new StereoAudioOutput( mThreadPoolManager,
-					mAvailableAudioOutputs.add( left );
+							entry.getMixer(), MixerChannel.LEFT );
-					mChannelNames.add( left.getChannelName() );
+					mAudioOutputConnections.add( new AudioOutputConnection( left ) );
+					mAvailableConnectionCount++;
 					mAudioOutputMap.put( left.getChannelName(), left );
 					
-					AudioOutput right = new StereoAudioOutput( entry.getMixer(), MixerChannel.RIGHT );
+					AudioOutput right = new StereoAudioOutput( mThreadPoolManager,
-					mAvailableAudioOutputs.add( right );
+							entry.getMixer(), MixerChannel.RIGHT );
-					mChannelNames.add( right.getChannelName() );
+					mAudioOutputConnections.add( new AudioOutputConnection( right ) );
+					mAvailableConnectionCount++;
 					mAudioOutputMap.put( right.getChannelName(), right );
 					break;
 				default:
@@ -392,10 +222,33 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 		}
 	}
 
+	/**
+	 * Clears all channel assignments and terminates all audio outputs in 
+	 * preparation for complete shutdown or change to another mixer/channel
+	 * configuration
+	 */
+	private void disposeCurrentConfiguration()
+	{
+		mChannelConnectionMap.clear();
+
+		for( AudioOutputConnection connection : mAudioOutputConnections )
+		{
+			connection.dispose();
+		}
+		
+		mAvailableConnectionCount = 0;
+
+		mAudioOutputConnections.clear();
+		
+		mAudioOutputMap.clear();
+		
+		mLowestPriorityConnection = null;
+	}
+
 	@Override
 	public MixerChannelConfiguration getMixerChannelConfiguration() throws AudioException
 	{
-		return mMixerChannel;
+		return mMixerChannelConfiguration;
 	}
 
 	@Override
@@ -426,4 +279,237 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 	{
 		mControllerBroadcaster.removeListener( listener );
 	}
+	
+	/**
+	 * Returns an audio output connection for the packet if one is 
+	 * available, or overrides an existing lower priority connection.  
+	 * Returns null if no connection is available for the audio packet.  
+	 * 
+	 * @param packet from a source
+	 * @return an audio output connection or null
+	 */
+	private AudioOutputConnection getConnection( AudioPacket packet )
+	{
+		int source = packet.getAudioMetadata().getSource();
+		
+		//Use an existing connection
+		if( mChannelConnectionMap.containsKey( source ) )
+		{
+			return mChannelConnectionMap.get( source );
+		}
+
+		//Connect to and use an available connection
+		if( mAvailableConnectionCount > 0 )
+		{
+			for( AudioOutputConnection connection: mAudioOutputConnections )
+			{
+				if( connection.isDisconnected() )
+				{
+					connection.connect( source );
+					mChannelConnectionMap.put( source, connection );
+					return connection;
+				}
+			}
+		}
+		//Preempt an existing connection and connect it to this higher priority source
+		else //Check for a channel priority override
+		{
+			int priority = packet.getAudioMetadata().getPriority();
+
+			if( mLowestPriorityConnection != null &&
+				priority < mLowestPriorityConnection.getPriority() )
+			{
+				AudioOutputConnection connection = mLowestPriorityConnection;
+
+				mChannelConnectionMap.remove( connection.getSource() );
+				
+				connection.connect( source );
+				
+				mChannelConnectionMap.put( source, connection );
+				
+				updateLowestPriorityAssignment();
+				
+				return connection;
+			}
+		}
+			
+		return null;
+	}
+	
+	public class AudioPacketProcessor implements Runnable
+	{
+		@Override
+		public void run()
+		{
+			disconnectInactiveChannelAssignments();
+			
+			if( mAudioPacketQueue != null )
+			{
+				List<AudioPacket> packets = new ArrayList<AudioPacket>();
+
+				mAudioPacketQueue.drainTo( packets );
+				
+				for( AudioPacket packet: packets )
+				{
+					/* Don't process any packet's marked as do not monitor */
+					if( !packet.getAudioMetadata().isDoNotMonitor() &&
+						packet.getType() == AudioPacket.Type.AUDIO )
+					{
+						AudioOutputConnection connection = getConnection( packet );
+
+						if( connection != null )
+						{
+							connection.receive( packet );
+						}
+					}
+				}
+			}
+		}
+	}
+	
+	/**
+	 * Audio output connection manages a connection between a soure and an audio
+	 * output and maintains current state information about the audio activity 
+	 * received form the source.
+	 */
+	public class AudioOutputConnection implements Listener<AudioEvent>
+	{
+		private static final long CALL_END_DELAY = 2000; //2 seconds
+		private static final int DISCONNECTED = -1;
+		
+		private AudioOutput mAudioOutput;
+		private int mPriority = 0;
+		private long mLastActivity = System.currentTimeMillis();
+		private int mSource = DISCONNECTED;
+		
+		public AudioOutputConnection( AudioOutput audioOutput )
+		{
+			mAudioOutput = audioOutput;
+			mAudioOutput.addAudioEventListener( this );
+		}
+		
+		public void receive( AudioPacket packet )
+		{
+			if( packet.hasAudioMetadata() && 
+				packet.getAudioMetadata().getSource() == mSource )
+			{
+				int priority = packet.getAudioMetadata().getPriority();
+
+				if( mPriority != priority )
+				{
+					mPriority = priority;
+					updateLowestPriorityAssignment();
+				}
+				
+				updateTimestamp();
+				
+				if( mAudioOutput != null )
+				{
+					mAudioOutput.receive( packet );
+				}
+			}
+			else
+			{
+				if( packet.hasAudioMetadata() )
+				{
+					mLog.error( "Received audio packet from channel source [" + 
+							packet.getAudioMetadata().getSource() + 
+							"] however this assignment is currently connected "
+							+ "to channel source [" + mSource + "]" );
+				}
+				else
+				{
+					mLog.error( "Received audio packet with no metadata - "
+							+ "cannot route audio packet" );
+				}
+			}
+		}
+		
+		private void updateTimestamp()
+		{
+			mLastActivity = System.currentTimeMillis();
+		}
+
+		/**
+		 * Terminates the audio output and prepares this connection for disposal
+		 */
+		public void dispose()
+		{
+			mAudioOutput.dispose();
+			mAudioOutput = null;
+		}
+
+		/**
+		 * Indicates if this assignment is currently disconnected from a channel source
+		 */
+		public boolean isDisconnected()
+		{
+			return mSource == DISCONNECTED;
+		}
+		
+		/**
+		 * Indicates if this assignment is currently connected to a channel source
+		 */
+		public boolean isConnected()
+		{
+			return !isDisconnected();
+		}
+
+		/**
+		 * Connects this assignment to the indicated source so that audio 
+		 * packets from this source can be sent to the audio output
+		 */
+		public void connect( int source )
+		{
+			mSource = source;
+			updateTimestamp();
+		}
+
+		/**
+		 * Currently connected source or -1 if disconnected
+		 */
+		public int getSource()
+		{
+			return mSource;
+		}
+
+		/**
+		 * Disconnects this assignment from the source and prevents any audio
+		 * from being routed to the audio output until another source is assigned
+		 */
+		public void disconnect()
+		{
+			mSource = DISCONNECTED;
+		}
+
+		/**
+		 * Indicates if audio output is current inactive, meaning that the 
+		 * audio output hasn't recently processed any audio packets.
+		 */
+		public boolean isInactive()
+		{
+			return mLastActivity != Long.MAX_VALUE &&
+				   mLastActivity + CALL_END_DELAY < System.currentTimeMillis();
+		}
+		
+		public int getPriority()
+		{
+			return mPriority;
+		}
+		
+		@Override
+		public void receive( AudioEvent event )
+		{
+			switch( event.getType() )
+			{
+				case AUDIO_STARTED:
+				case AUDIO_STOPPED:
+				case AUDIO_CONTINUATION:
+					updateTimestamp();
+					break;
+				default:
+					break;
+			}
+		}
+	}
 }

src/audio/output/AudioOutput.java

@@ -1,7 +1,6 @@
 package audio.output;
 
 import java.util.concurrent.LinkedTransferQueue;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import javax.sound.sampled.FloatControl;
@@ -15,6 +14,7 @@ import audio.AudioEvent;
 import audio.AudioEvent.Type;
 import audio.AudioPacket;
 import audio.metadata.AudioMetadata;
+import controller.ThreadPoolManager;
 
 public abstract class AudioOutput implements Listener<AudioPacket>
 {
@@ -25,10 +25,15 @@ public abstract class AudioOutput implements Listener<AudioPacket>
 
 	protected Broadcaster<AudioEvent> mAudioEventBroadcaster = new Broadcaster<>();
 	protected LinkedTransferQueue<AudioPacket> mBuffer = new LinkedTransferQueue<>();
-	protected ScheduledExecutorService mExecutorService;
+	protected ThreadPoolManager mThreadPoolManager;
 	protected boolean mCanProcessAudio;
 	protected long mLastActivity;
 
+	public AudioOutput( ThreadPoolManager threadPoolManager )
+	{
+		mThreadPoolManager = threadPoolManager;
+	}
+	
 	public void reset()
 	{
 		broadcast( new AudioEvent( AudioEvent.Type.AUDIO_STOPPED, 
@@ -41,14 +46,11 @@ public abstract class AudioOutput implements Listener<AudioPacket>
 
 		mBuffer.clear();
 
-		if( mExecutorService != null )
-		{
-			mExecutorService.shutdown();
-		}
-
 		mAudioEventBroadcaster.dispose();
 		mAudioEventBroadcaster = null;
 		mAudioMetadataListener = null;
+		
+		mThreadPoolManager = null;
 	}
 	
 	public abstract String getChannelName();

src/audio/output/MonoAudioOutput.java

@@ -5,7 +5,7 @@ import java.nio.ByteOrder;
 import java.nio.ShortBuffer;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -24,7 +24,8 @@ import audio.AudioEvent;
 import audio.AudioFormats;
 import audio.AudioPacket;
 import audio.AudioPacket.Type;
-import controller.NamingThreadFactory;
+import controller.ThreadPoolManager;
+import controller.ThreadPoolManager.ThreadType;
 
 /**
  * Mono Audio output with automatic flow control based on the availability of 
@@ -54,9 +55,11 @@ public class MonoAudioOutput extends AudioOutput
 	private AudioEvent mAudioStopEvent;
 	private AudioEvent mAudioContinuationEvent;
 	
-	public MonoAudioOutput( Mixer mixer )
+	private ScheduledFuture<?> mProcessorTask;
+	
+	public MonoAudioOutput( ThreadPoolManager threadPoolManager, Mixer mixer )
 	{
-		super();
+		super( threadPoolManager );
 
 		mAudioStartEvent = new AudioEvent( AudioEvent.Type.AUDIO_STARTED, 
 				getChannelName() );
@@ -73,15 +76,7 @@ public class MonoAudioOutput extends AudioOutput
 			if( mOutput != null )
 			{
 				mOutput.open( AudioFormats.PCM_SIGNED_48KHZ_16BITS_MONO, BUFFER_SIZE );
-				
 				mCanProcessAudio = true;
-				
-				mExecutorService = Executors.newSingleThreadScheduledExecutor( 
-						new NamingThreadFactory( "audio (mono) output" ) );
-
-				/* Run the queue processor task every 40 milliseconds */
-				mExecutorService.scheduleAtFixedRate( new QueueProcessor(), 
-						0, 40, TimeUnit.MILLISECONDS );
 			}
 		} 
         catch ( LineUnavailableException e )
@@ -114,12 +109,10 @@ public class MonoAudioOutput extends AudioOutput
 					mixer.getMixerInfo().getName() + "]" );
 			}
 			
-			mExecutorService = Executors.newSingleThreadScheduledExecutor( 
-					new NamingThreadFactory( "audio (mono) output" ) );
-
 			/* Run the queue processor task every 40 milliseconds */
-			mExecutorService.scheduleAtFixedRate( new QueueProcessor(), 
+			mProcessorTask = mThreadPoolManager.scheduleFixedRate( 
-					0, 40, TimeUnit.MILLISECONDS );
+				ThreadType.AUDIO_PROCESSING, new QueueProcessor(), 
+				40, TimeUnit.MILLISECONDS );
 		}
 	}
 
@@ -131,12 +124,23 @@ public class MonoAudioOutput extends AudioOutput
 
 	public void dispose()
 	{
+		if( mProcessorTask != null && mThreadPoolManager != null )
+		{
+			mThreadPoolManager.cancel( mProcessorTask );
+		}
+		
+		mProcessorTask = null;
+		
 		super.dispose();
 		
 		if( mOutput != null )
 		{
 			mOutput.close();
 		}
+		
+		mOutput = null;
+		mGainControl = null;
+		mMuteControl = null;
 	}
 	
 	public class QueueProcessor implements Runnable
@@ -184,55 +188,10 @@ public class MonoAudioOutput extends AudioOutput
 										shortBuffer.put( (short)( sample * Short.MAX_VALUE ) );
 									}
 									
-									if( mOutput.available() >= buffer.array().length )
+									//This is a blocking write
-									{
+									mOutput.write( buffer.array(), 0, buffer.array().length );
-										mOutput.write( buffer.array(), 0, 
-												buffer.array().length );
 
 									checkStart();
-									}
-									else
-									{
-										int wrote = 0;
-
-										int toWrite = buffer.array().length;
-										
-										while( toWrite > 0 )
-										{
-											int available = mOutput.available();
-
-											if( available < toWrite )
-											{
-												if( available > 0 )
-												{
-													wrote += mOutput.write( buffer.array(), 
-														wrote, available );
-
-													checkStart();
-												}
-												else
-												{
-													try
-													{
-														Thread.sleep( 100 );
-													} 
-													catch ( InterruptedException e )
-													{
-														mLog.debug( "Mono Audio Output - interrupted while sleeping awaiting buffer drain" );
-													}
-												}
-											}
-											else
-											{
-												wrote += mOutput.write( buffer.array(), wrote, 
-														toWrite );
-												
-												checkStart();
-											}
-											
-											toWrite = buffer.array().length - wrote;
-										}
-									}
 
 									broadcast( packet.getAudioMetadata() );
 

src/audio/output/StereoAudioOutput.java

@@ -5,7 +5,7 @@ import java.nio.ByteOrder;
 import java.nio.ShortBuffer;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -24,7 +24,8 @@ import audio.AudioEvent;
 import audio.AudioFormats;
 import audio.AudioPacket;
 import audio.AudioPacket.Type;
-import controller.NamingThreadFactory;
+import controller.ThreadPoolManager;
+import controller.ThreadPoolManager.ThreadType;
 
 /**
  * Mono Audio output in stereo format with automatic flow control based on the 
@@ -56,9 +57,12 @@ public class StereoAudioOutput extends AudioOutput
 	
 	private MixerChannel mMixerChannel;
 	
-	public StereoAudioOutput( Mixer mixer, MixerChannel channel )
+	private ScheduledFuture<?> mProcessorTask;
+	
+	public StereoAudioOutput( ThreadPoolManager threadPoolManager, 
+			Mixer mixer, MixerChannel channel )
 	{
-		super();
+		super( threadPoolManager );
 		
 		assert( channel == MixerChannel.LEFT || channel == MixerChannel.RIGHT );
 		
@@ -113,12 +117,10 @@ public class StereoAudioOutput extends AudioOutput
 					mixer.getMixerInfo().getName() + " | " + channel.name() + "]" );
 			}
 			
-			mExecutorService = Executors.newSingleThreadScheduledExecutor( 
-					new NamingThreadFactory( "audio (stereo) output" ) );
-
 			/* Run the queue processor task every 40 milliseconds */
-			mExecutorService.scheduleAtFixedRate( new QueueProcessor(), 
+			mProcessorTask = mThreadPoolManager.scheduleFixedRate( 
-					0, 40, TimeUnit.MILLISECONDS );
+				ThreadType.AUDIO_PROCESSING, new QueueProcessor(), 
+				40, TimeUnit.MILLISECONDS );
 		}
 	}
 
@@ -130,12 +132,23 @@ public class StereoAudioOutput extends AudioOutput
 
 	public void dispose()
 	{
+		if( mProcessorTask != null && mThreadPoolManager != null )
+		{
+			mThreadPoolManager.cancel( mProcessorTask );
+		}
+		
+		mProcessorTask = null;
+
 		super.dispose();
 		
 		if( mOutput != null )
 		{
 			mOutput.close();
 		}
+		
+		mOutput = null;
+		mGainControl = null;
+		mMuteControl = null;
 	}
 	
 	private ByteBuffer convert( float[] samples )
@@ -204,44 +217,10 @@ public class StereoAudioOutput extends AudioOutput
 									ByteBuffer buffer = convert( 
 											packet.getAudioBuffer().getSamples() );
 									
-									if( mOutput.available() >= buffer.array().length )
-									{
 									mOutput.write( buffer.array(), 0, 
 											buffer.array().length );
 
 									checkStart();
-									}
-									else
-									{
-										int wrote = 0;
-
-										int toWrite = buffer.array().length;
-										
-										while( toWrite > 0 )
-										{
-											int available = mOutput.available();
-
-											if( available < toWrite )
-											{
-												if( available > 0 )
-												{
-													wrote += mOutput.write( buffer.array(), 
-															wrote, available );
-
-													checkStart();
-												}
-											}
-											else
-											{
-												wrote += mOutput.write( buffer.array(), wrote, 
-														toWrite );
-
-												checkStart();
-											}
-
-											toWrite = buffer.array().length - wrote;
-										}
-									}
 									
 									broadcast( packet.getAudioMetadata() );
 									

src/controller/ThreadPoolManager.java

@@ -36,7 +36,9 @@ public class ThreadPoolManager
 	private HashMap<ScheduledFuture<?>,ThreadType> mTasks = 
 				new HashMap<ScheduledFuture<?>,ThreadType>();
 	
-	private ScheduledExecutorService mExecutor;
+	private ScheduledExecutorService mExecutor = 
+			Executors.newScheduledThreadPool( THREAD_POOL_SIZE, 
+					new NamingThreadFactory( "sdrtrunk" ) );
 	
 	public ThreadPoolManager()
 	{
@@ -48,12 +50,6 @@ public class ThreadPoolManager
 										TimeUnit unit )
 										throws RejectedExecutionException
 	{
-		if( mExecutor == null )
-		{
-			mExecutor = Executors.newScheduledThreadPool( THREAD_POOL_SIZE, 
-					new NamingThreadFactory( "sdrtrunk" ) );
-		}
-
 		ScheduledFuture<?> task = 
 				mExecutor.scheduleAtFixedRate( command, 0, period, unit );
 		
@@ -65,12 +61,6 @@ public class ThreadPoolManager
 	public void scheduleOnce( Runnable command, long delay, TimeUnit unit )	
 			throws RejectedExecutionException
 	{
-		if( mExecutor == null )
-		{
-			mExecutor = Executors.newScheduledThreadPool( THREAD_POOL_SIZE, 
-					new NamingThreadFactory( "sdrtrunk" ) );
-		}
-		
 		mExecutor.schedule( command, delay, unit );
 	}