DV serial: alternate timeout handling. Primitives to get information about worker status

sdrbase/dsp/dvserialengine.cpp

@@ -199,7 +199,6 @@ bool DVSerialEngine::scan()
             connect(controller.worker, SIGNAL(finished()), controller.worker, SLOT(deleteLater()));
             connect(controller.thread, SIGNAL(finished()), controller.thread, SLOT(deleteLater()));
             connect(&controller.worker->m_inputMessageQueue, SIGNAL(messageEnqueued()), controller.worker, SLOT(handleInputMessages()));
-            connect(controller.worker->m_timer, SIGNAL(timeout()), controller.worker, SLOT(releaseQueue()));
             controller.thread->start();
 
             m_controllers.push_back(controller);
@@ -255,12 +254,12 @@ void DVSerialEngine::pushMbeFrame(const unsigned char *mbeFrame, int mbeRateInde
 
     while (it != m_controllers.end())
     {
-        if (it->worker->m_audioFifo == audioFifo)
+        if (it->worker->hasFifo(audioFifo))
         {
             it->worker->pushMbeFrame(mbeFrame, mbeRateIndex, mbeVolumeIndex, channels, audioFifo);
             done = true;
         }
-        else if (it->worker->m_audioFifo == 0)
+        else if (it->worker->isAvailable())
         {
             itAvail = it;
         }

sdrbase/dsp/dvserialworker.cpp

@@ -33,13 +33,10 @@ DVSerialWorker::DVSerialWorker() :
     m_audioBuffer.resize(48000);
     m_audioBufferFill = 0;
     m_audioFifo = 0;
-    m_timer = new QTimer(this);
-    m_timer->setSingleShot(true);
 }
 
 DVSerialWorker::~DVSerialWorker()
 {
-    delete m_timer;
 }
 
 bool DVSerialWorker::open(const std::string& serialDevice)
@@ -73,7 +70,6 @@ void DVSerialWorker::stop()
 
 void DVSerialWorker::handleInputMessages()
 {
-    m_timer->stop(); // suspend FIFO queue holding timeout
     Message* message;
     m_audioBufferFill = 0;
     AudioFifo *audioFifo = 0;
@@ -109,7 +105,7 @@ void DVSerialWorker::handleInputMessages()
         }
     }
 
-    m_timer->start(1000); // FIFO queue holding timeout
+    m_timestamp = QDateTime::currentDateTime();
 }
 
 void DVSerialWorker::pushMbeFrame(const unsigned char *mbeFrame,
@@ -121,10 +117,18 @@ void DVSerialWorker::pushMbeFrame(const unsigned char *mbeFrame,
     m_inputMessageQueue.push(MsgMbeDecode::create(mbeFrame, mbeRateIndex, mbeVolumeIndex, channels, audioFifo));
 }
 
-void DVSerialWorker::releaseQueue()
+bool DVSerialWorker::isAvailable()
 {
-    qDebug("DVSerialWorker::releaseQueue: release %p", m_audioFifo);
-    m_audioFifo = 0;
+	if (m_audioFifo == 0) {
+		return true;
+	}
+
+	return m_timestamp.time().msecsTo(QDateTime::currentDateTime().time()) > 1000; // 1 second inactivity timeout
+}
+
+bool DVSerialWorker::hasFifo(AudioFifo *audioFifo)
+{
+    return m_audioFifo == audioFifo;
 }
 
 void DVSerialWorker::upsample6(short *in, int nbSamplesIn, unsigned char channels, AudioFifo *audioFifo)

sdrbase/dsp/dvserialworker.h

@@ -21,6 +21,7 @@
 #include <QObject>
 #include <QDebug>
 #include <QTimer>
+#include <QDateTime>
 
 #include <vector>
 
@@ -94,6 +95,8 @@ public:
     void close();
     void process();
     void stop();
+    bool isAvailable();
+    bool hasFifo(AudioFifo *audioFifo);
 
     void postTest()
     {
@@ -103,14 +106,13 @@ public:
 
     MessageQueue m_inputMessageQueue; //!< Queue for asynchronous inbound communication
     AudioFifo *m_audioFifo;
-    QTimer *m_timer;
+    QDateTime m_timestamp;
 
 signals:
     void finished();
 
 public slots:
     void handleInputMessages();
-    void releaseQueue();
 
 private:
     struct AudioSample {