decouple audio-mixer packet receipt from main thread

assignment-client/src/audio/AudioMixer.cpp

@@ -37,6 +37,7 @@
 #include <QtCore/QJsonDocument>
 #include <QtCore/QJsonObject>
 #include <QtCore/QJsonValue>
+#include <QtCore/QThread>
 #include <QtCore/QTimer>
 #include <QtNetwork/QNetworkRequest>
 #include <QtNetwork/QNetworkReply>
@@ -52,6 +53,7 @@
 
 #include "AudioRingBuffer.h"
 #include "AudioMixerClientData.h"
+#include "AudioMixerDatagramProcessor.h"
 #include "AvatarAudioStream.h"
 #include "InjectedAudioStream.h"
 
@@ -297,37 +299,31 @@ void AudioMixer::prepareMixForListeningNode(Node* node) {
     }
 }
 
-void AudioMixer::readPendingDatagrams() {
-    QByteArray receivedPacket;
-    HifiSockAddr senderSockAddr;
+void AudioMixer::readPendingDatagram(const QByteArray& receivedPacket, const HifiSockAddr& senderSockAddr) {
     NodeList* nodeList = NodeList::getInstance();
     
-    while (readAvailableDatagram(receivedPacket, senderSockAddr)) {
-        if (nodeList->packetVersionAndHashMatch(receivedPacket)) {
-            // pull any new audio data from nodes off of the network stack
-            PacketType mixerPacketType = packetTypeForPacket(receivedPacket);
-            if (mixerPacketType == PacketTypeMicrophoneAudioNoEcho
-                || mixerPacketType == PacketTypeMicrophoneAudioWithEcho
-                || mixerPacketType == PacketTypeInjectAudio
-                || mixerPacketType == PacketTypeSilentAudioFrame
-                || mixerPacketType == PacketTypeAudioStreamStats) {
-                
-                nodeList->findNodeAndUpdateWithDataFromPacket(receivedPacket);
-            } else if (mixerPacketType == PacketTypeMuteEnvironment) {
-                QByteArray packet = receivedPacket;
-                populatePacketHeader(packet, PacketTypeMuteEnvironment);
-                
-                foreach (const SharedNodePointer& node, nodeList->getNodeHash()) {
-                    if (node->getType() == NodeType::Agent && node->getActiveSocket() && node->getLinkedData() && node != nodeList->sendingNodeForPacket(receivedPacket)) {
-                        nodeList->writeDatagram(packet, packet.size(), node);
-                    }
-                }
-
-            } else {
-                // let processNodeData handle it.
-                nodeList->processNodeData(senderSockAddr, receivedPacket);
+    // pull any new audio data from nodes off of the network stack
+    PacketType mixerPacketType = packetTypeForPacket(receivedPacket);
+    if (mixerPacketType == PacketTypeMicrophoneAudioNoEcho
+        || mixerPacketType == PacketTypeMicrophoneAudioWithEcho
+        || mixerPacketType == PacketTypeInjectAudio
+        || mixerPacketType == PacketTypeSilentAudioFrame
+        || mixerPacketType == PacketTypeAudioStreamStats) {
+        
+        nodeList->findNodeAndUpdateWithDataFromPacket(receivedPacket);
+    } else if (mixerPacketType == PacketTypeMuteEnvironment) {
+        QByteArray packet = receivedPacket;
+        populatePacketHeader(packet, PacketTypeMuteEnvironment);
+        
+        foreach (const SharedNodePointer& node, nodeList->getNodeHash()) {
+            if (node->getType() == NodeType::Agent && node->getActiveSocket() && node->getLinkedData() && node != nodeList->sendingNodeForPacket(receivedPacket)) {
+                nodeList->writeDatagram(packet, packet.size(), node);
             }
         }
+        
+    } else {
+        // let processNodeData handle it.
+        nodeList->processNodeData(senderSockAddr, receivedPacket);
     }
 }
 
@@ -392,7 +388,35 @@ void AudioMixer::run() {
     ThreadedAssignment::commonInit(AUDIO_MIXER_LOGGING_TARGET_NAME, NodeType::AudioMixer);
 
     NodeList* nodeList = NodeList::getInstance();
-
+    
+    // we do not want this event loop to be the handler for UDP datagrams, so disconnect
+    disconnect(&nodeList->getNodeSocket(), 0, this, 0);
+    
+    // setup a QThread with us as parent that will house the AudioMixerDatagramProcessor
+    _datagramProcessingThread = new QThread(this);
+    
+    // create an AudioMixerDatagramProcessor and move it to that thread
+    AudioMixerDatagramProcessor* datagramProcessor = new AudioMixerDatagramProcessor(nodeList->getNodeSocket(), thread());
+    datagramProcessor->moveToThread(_datagramProcessingThread);
+    
+    // remove the NodeList as the parent of the node socket
+    nodeList->getNodeSocket().setParent(NULL);
+    nodeList->getNodeSocket().moveToThread(_datagramProcessingThread);
+    
+    // let the datagram processor handle readyRead from node socket
+    connect(&nodeList->getNodeSocket(), &QUdpSocket::readyRead,
+            datagramProcessor, &AudioMixerDatagramProcessor::readPendingDatagrams);
+    
+    // connect to the datagram processing thread signal that tells us we have to handle a packet
+    connect(datagramProcessor, &AudioMixerDatagramProcessor::packetRequiresProcessing, this, &AudioMixer::readPendingDatagram);
+    
+    // delete the datagram processor and the associated thread when the QThread quits
+    connect(_datagramProcessingThread, &QThread::finished, datagramProcessor, &QObject::deleteLater);
+    connect(datagramProcessor, &QObject::destroyed, _datagramProcessingThread, &QThread::deleteLater);
+    
+    // start the datagram processing thread
+    _datagramProcessingThread->start();
+    
     nodeList->addNodeTypeToInterestSet(NodeType::Agent);
 
     nodeList->linkedDataCreateCallback = attachNewNodeDataToNode;

assignment-client/src/audio/AudioMixer.h

@@ -33,7 +33,8 @@ public slots:
     /// threaded run of assignment
     void run();
     
-    void readPendingDatagrams();
+    void readPendingDatagrams() { }; // this will not be called since our datagram processing thread will handle
+    void readPendingDatagram(const QByteArray& receivedPacket, const HifiSockAddr& senderSockAddr);
     
     void sendStatsPacket();
 

assignment-client/src/audio/AudioMixerDatagramProcessor.cpp

@@ -0,0 +1,51 @@
+//
+//  AudioMixerDatagramProcessor.cpp
+//  assignment-client/src
+//
+//  Created by Stephen Birarda on 2014-08-14.
+//  Copyright 2014 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include <QDebug>
+
+#include <HifiSockAddr.h>
+#include <NodeList.h>
+
+#include "AudioMixerDatagramProcessor.h"
+
+AudioMixerDatagramProcessor::AudioMixerDatagramProcessor(QUdpSocket& nodeSocket, QThread* previousNodeSocketThread) :
+    _nodeSocket(nodeSocket),
+    _previousNodeSocketThread(previousNodeSocketThread)
+{
+    
+}
+
+AudioMixerDatagramProcessor::~AudioMixerDatagramProcessor() {    
+    // return the node socket to its previous thread
+    _nodeSocket.moveToThread(_previousNodeSocketThread);
+}
+
+void AudioMixerDatagramProcessor::readPendingDatagrams() {
+    
+    HifiSockAddr senderSockAddr;
+    static QByteArray incomingPacket;
+    
+    NodeList* nodeList = NodeList::getInstance();
+    
+    // read everything that is available
+    while (_nodeSocket.hasPendingDatagrams()) {
+        incomingPacket.resize(_nodeSocket.pendingDatagramSize());
+        
+        // just get this packet off the stack
+        _nodeSocket.readDatagram(incomingPacket.data(), incomingPacket.size(),
+                                  senderSockAddr.getAddressPointer(), senderSockAddr.getPortPointer());
+        
+        if (nodeList->packetVersionAndHashMatch(incomingPacket)) {
+            // emit the signal to tell AudioMixer it needs to process a packet
+            emit packetRequiresProcessing(incomingPacket, senderSockAddr);
+        }
+    }
+}

assignment-client/src/audio/AudioMixerDatagramProcessor.h

@@ -0,0 +1,32 @@
+//
+//  AudioMixerDatagramProcessor.h
+//  assignment-client/src
+//
+//  Created by Stephen Birarda on 2014-08-14.
+//  Copyright 2014 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef hifi_AudioMixerDatagramProcessor_h
+#define hifi_AudioMixerDatagramProcessor_h
+
+#include <qobject.h>
+#include <qudpsocket.h>
+
+class AudioMixerDatagramProcessor : public QObject {
+    Q_OBJECT
+public:
+    AudioMixerDatagramProcessor(QUdpSocket& nodeSocket, QThread* previousNodeSocketThread);
+    ~AudioMixerDatagramProcessor();
+public slots:
+    void readPendingDatagrams();
+signals:
+    void packetRequiresProcessing(const QByteArray& receivedPacket, const HifiSockAddr& senderSockAddr);
+private:
+    QUdpSocket& _nodeSocket;
+    QThread* _previousNodeSocketThread;
+};
+
+#endif // hifi_AudioMixerDatagramProcessor_h

libraries/networking/src/LimitedNodeList.cpp

@@ -160,11 +160,7 @@ void LimitedNodeList::changeSocketBufferSizes(int numBytes) {
             qDebug() << "Did not change socket" << bufferTypeString << "buffer size from" << oldBufferSize
                 << "since it is larger than desired size of" << numBytes;
         }
-        
-        
     }
-    
-    
 }
 
 bool LimitedNodeList::packetVersionAndHashMatch(const QByteArray& packet) {

libraries/networking/src/ThreadedAssignment.cpp

@@ -11,6 +11,7 @@
 
 #include <QtCore/QCoreApplication>
 #include <QtCore/QJsonObject>
+#include <QtCore/QThread>
 #include <QtCore/QTimer>
 
 #include "Logging.h"
@@ -18,7 +19,8 @@
 
 ThreadedAssignment::ThreadedAssignment(const QByteArray& packet) :
     Assignment(packet),
-    _isFinished(false)
+    _isFinished(false),
+    _datagramProcessingThread(NULL)
 {
     
 }
@@ -28,10 +30,25 @@ void ThreadedAssignment::setFinished(bool isFinished) {
 
     if (_isFinished) {
         aboutToFinish();
-        emit finished();
+        
+        NodeList* nodeList = NodeList::getInstance();
+        
+        // if we have a datagram processing thread, quit it and wait on it to make sure that
+        // the node socket is back on the same thread as the NodeList
+        
+        if (_datagramProcessingThread) {
+            // tell the datagram processing thread to quit and wait until it is done, then return the node socket to the NodeList
+            _datagramProcessingThread->quit();
+            _datagramProcessingThread->wait();
+            
+            // set node socket parent back to NodeList
+            nodeList->getNodeSocket().setParent(nodeList);
+        }
         
         // move the NodeList back to the QCoreApplication instance's thread
-        NodeList::getInstance()->moveToThread(QCoreApplication::instance()->thread());
+        nodeList->moveToThread(QCoreApplication::instance()->thread());
+        
+        emit finished();
     }
 }
 

libraries/networking/src/ThreadedAssignment.h

@@ -20,6 +20,7 @@ class ThreadedAssignment : public Assignment {
     Q_OBJECT
 public:
     ThreadedAssignment(const QByteArray& packet);
+    
     void setFinished(bool isFinished);
     virtual void aboutToFinish() { };
     void addPacketStatsAndSendStatsPacket(QJsonObject& statsObject);
@@ -29,15 +30,18 @@ public slots:
     virtual void run() = 0;
     virtual void readPendingDatagrams() = 0;
     virtual void sendStatsPacket();
-
+signals:
+    void finished();
+    
 protected:
     bool readAvailableDatagram(QByteArray& destinationByteArray, HifiSockAddr& senderSockAddr);
     void commonInit(const QString& targetName, NodeType_t nodeType, bool shouldSendStats = true);
     bool _isFinished;
+    QThread* _datagramProcessingThread;
+    
 private slots:
     void checkInWithDomainServerOrExit();
-signals:
-    void finished();
+
 };
 
 typedef QSharedPointer<ThreadedAssignment> SharedAssignmentPointer;