From 2faaa93785f25070fbfbcaf88c423eddd48b8b4f Mon Sep 17 00:00:00 2001
From: Denny <denny@denny-desktop>
Date: Sun, 22 Jan 2017 07:20:24 -0500
Subject: [PATCH] #111 resolves issue with probable thread contention on
 temporary streamed recording queue management that was causing processing
 thread backups and memory issues.  Audio broadcaster was originally in this
 configuration but was changed to account for a potential issue where
 recordings could be streamed out of sequence if they occurred at the same
 time.  Reverted queue type back to a more efficient FIFO linked transfer
 queue to minimize queue contention.

---
 src/audio/broadcast/AudioBroadcaster.java | 29 +++++++----------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/src/audio/broadcast/AudioBroadcaster.java b/src/audio/broadcast/AudioBroadcaster.java
index 877543fc..8644e4da 100644
--- a/src/audio/broadcast/AudioBroadcaster.java
+++ b/src/audio/broadcast/AudioBroadcaster.java
@@ -28,9 +28,8 @@ import sample.Listener;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.nio.file.Files;
-import java.util.Iterator;
-import java.util.List;
-import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.Queue;
+import java.util.concurrent.LinkedTransferQueue;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -45,7 +44,7 @@ public abstract class AudioBroadcaster implements Listener<AudioRecording>
     private ScheduledFuture mScheduledTask;
 
     private RecordingQueueProcessor mRecordingQueueProcessor = new RecordingQueueProcessor();
-    private List<AudioRecording> mAudioRecordingQueue = new CopyOnWriteArrayList<>();
+    private Queue<AudioRecording> mAudioRecordingQueue = new LinkedTransferQueue<>();
 
     private ISilenceGenerator mSilenceGenerator;
 
@@ -197,7 +196,7 @@ public abstract class AudioBroadcaster implements Listener<AudioRecording>
     {
         if(connected())
         {
-            mAudioRecordingQueue.add(recording);
+            mAudioRecordingQueue.offer(recording);
             broadcast(new BroadcastEvent(this, BroadcastEvent.Event.BROADCASTER_QUEUE_CHANGE));
         }
     }
@@ -261,7 +260,7 @@ public abstract class AudioBroadcaster implements Listener<AudioRecording>
                 {
                     try
                     {
-                        AudioRecording recording = mAudioRecordingQueue.get(0);
+                        AudioRecording recording = mAudioRecordingQueue.remove();
                         recording.removePendingReplay();
                     }
                     catch(Exception e)
@@ -397,24 +396,12 @@ public abstract class AudioBroadcaster implements Listener<AudioRecording>
 
             mInputStream = null;
 
-            AudioRecording nextRecording = null;
-
-            //Find the recording with the earliest start time
-            Iterator<AudioRecording> it = mAudioRecordingQueue.iterator();
-
-            while(it.hasNext())
-            {
-                AudioRecording recording = it.next();
-
-                if(nextRecording == null || (recording.getStartTime() < nextRecording.getStartTime()))
-                {
-                    nextRecording = recording;
-                }
-            }
+            //Peek at the next recording but don't remove it from the queue yet, so we can inspect the delay time
+            AudioRecording nextRecording = mAudioRecordingQueue.peek();
 
             if(nextRecording != null && nextRecording.getStartTime() + mDelay <= System.currentTimeMillis())
             {
-                mAudioRecordingQueue.remove(nextRecording);
+                nextRecording = mAudioRecordingQueue.remove();
 
                 try
                 {