some QThread cleanup and fix in Socket

interface/src/Application.cpp

@@ -457,8 +457,7 @@ Application::Application(int& argc, char** argv, QElapsedTimer &startup_time) :
 
     audioThread->start();
 
-
+    QThread* assetThread = new QThread;
-    QThread* assetThread = new QThread();
 
     assetThread->setObjectName("Asset Thread");
     auto assetClient = DependencyManager::get<AssetClient>();
@@ -467,7 +466,6 @@ Application::Application(int& argc, char** argv, QElapsedTimer &startup_time) :
 
     assetThread->start();
 
-
     const DomainHandler& domainHandler = nodeList->getDomainHandler();
 
     connect(&domainHandler, SIGNAL(hostnameChanged(const QString&)), SLOT(domainChanged(const QString&)));
@@ -879,6 +877,12 @@ Application::~Application() {
     DependencyManager::destroy<ScriptCache>();
     DependencyManager::destroy<SoundCache>();
     
+    // cleanup the AssetClient thread
+    QThread* assetThread = DependencyManager::get<AssetClient>()->thread();
+    DependencyManager::destroy<AssetClient>();
+    assetThread->quit();
+    assetThread->wait();
+
     QThread* nodeThread = DependencyManager::get<NodeList>()->thread();
     
     // remove the NodeList from the DependencyManager

libraries/networking/src/AssetClient.cpp

@@ -24,6 +24,11 @@ MessageID AssetClient::_currentID = 0;
 
 
 AssetClient::AssetClient() {
+    
+    setCustomDeleter([](Dependency* dependency){
+        static_cast<AssetClient*>(dependency)->deleteLater();
+    });
+    
     auto& packetReceiver = DependencyManager::get<NodeList>()->getPacketReceiver();
     packetReceiver.registerListener(PacketType::AssetGetInfoReply, this, "handleAssetGetInfoReply");
     packetReceiver.registerMessageListener(PacketType::AssetGetReply, this, "handleAssetGetReply");

libraries/networking/src/udt/SendQueue.cpp

@@ -53,7 +53,7 @@ std::unique_ptr<SendQueue> SendQueue::create(Socket* socket, HifiSockAddr destin
     Q_ASSERT_X(socket, "SendQueue::create", "Must be called with a valid Socket*");
     
     // Setup queue private thread
-    QThread* thread = new QThread();
+    QThread* thread = new QThread;
     thread->setObjectName("Networking: SendQueue " + destination.objectName()); // Name thread for easier debug
     
     connect(thread, &QThread::started, queue.get(), &SendQueue::run);

libraries/networking/src/udt/Socket.cpp

@@ -30,10 +30,10 @@ Socket::Socket(QObject* parent) :
     connect(&_udpSocket, &QUdpSocket::readyRead, this, &Socket::readPendingDatagrams);
     
     // make sure our synchronization method is called every SYN interval
-    connect(&_synTimer, &QTimer::timeout, this, &Socket::rateControlSync);
+    connect(_synTimer, &QTimer::timeout, this, &Socket::rateControlSync);
     
     // start our timer for the synchronization time interval
-    _synTimer.start(_synInterval);
+    _synTimer->start(_synInterval);
 }
 
 void Socket::rebind() {
@@ -262,10 +262,10 @@ void Socket::rateControlSync() {
         connection.second->sync();
     }
     
-    if (_synTimer.interval() != _synInterval) {
+    if (_synTimer->interval() != _synInterval) {
         // if the _synTimer interval doesn't match the current _synInterval (changes when the CC factory is changed)
         // then restart it now with the right interval
-        _synTimer.start(_synInterval);
+        _synTimer->start(_synInterval);
     }
 }
 

libraries/networking/src/udt/Socket.h

@@ -43,6 +43,7 @@ class Socket : public QObject {
     Q_OBJECT
 public:
     Socket(QObject* object = 0);
+    ~Socket();
     
     quint16 localPort() const { return _udpSocket.localPort(); }
     
@@ -97,7 +98,7 @@ private:
     QMutex _connectionsMutex; // guards concurrent access to connections hashs
     
     int _synInterval = 10; // 10ms
-    QTimer _synTimer;
+    QTimer* _synTimer;
     
     std::unique_ptr<CongestionControlVirtualFactory> _ccFactory { new CongestionControlFactory<DefaultCC>() };
 };

libraries/shared/src/GenericThread.cpp

@@ -19,6 +19,7 @@ GenericThread::GenericThread(QObject* parent) :
     _stopThread(false),
     _isThreaded(false) // assume non-threaded, must call initialize()
 {
+    
 }
 
 GenericThread::~GenericThread() {