Make IOThreads terminate() fully non-blocking and misc.

- Thanks to timed-pop() usage, it is no longer needed to nudge queues with dummy to wake them
- Less bad luck to be stuck there
- Misc: leave the trace about the audio thread staturation, useful despite it raises some alarm among users...

src/audio/AudioThread.cpp

@@ -476,9 +476,6 @@ void AudioThread::run() {
 
 void AudioThread::terminate() {
     IOThread::terminate();
-    AudioThreadCommand endCond;   // push an empty input to bump the queue
-    //VSO: blocking push
-    cmdQueue.push(endCond);
 }
 
 bool AudioThread::isActive() {

src/demod/DemodulatorPreThread.cpp

@@ -348,18 +348,10 @@ int DemodulatorPreThread::getAudioSampleRate() {
 
 void DemodulatorPreThread::terminate() {
 
-    //make non-blocking calls to be sure threads are flagged for termination before attempting the blocking calls.
+    //make non-blocking calls to be sure threads are flagged for termination.
     IOThread::terminate();
     workerThread->terminate();
 
-    DemodulatorThreadIQDataPtr inp(new DemodulatorThreadIQData);    // push dummy to nudge queue
-    //VSO: blocking push :
-    iqInputQueue->push(inp);
- 
-    DemodulatorWorkerThreadCommand command;
-    //VSO: blocking push :
-    workerQueue->push(command);
-
     //wait blocking for termination here, it could be long with lots of modems and we MUST terminate properly,
     //else better kill the whole application...
     workerThread->isTerminated(5000);

src/demod/DemodulatorThread.cpp

@@ -313,8 +313,8 @@ void DemodulatorThread::run() {
             if (!muted.load() && (!wxGetApp().getSoloMode() || (demodInstance == wxGetApp().getDemodMgr().getLastActiveDemodulator()))) {
                 //non-blocking push needed for audio out
                 if (!audioOutputQueue->try_push(ati)) {
-                    //Comment this trace, it creates to many false alarms :)
-                    //std::cout << "DemodulatorThread::run() cannot push ati into audioOutputQueue, is full !" << std::endl;
+                  
+                    std::cout << "DemodulatorThread::run() cannot push ati into audioOutputQueue, is full !" << std::endl;
                     std::this_thread::yield();
                 }
             }
@@ -348,10 +348,6 @@ void DemodulatorThread::run() {
 
 void DemodulatorThread::terminate() {
     IOThread::terminate();
-    DemodulatorThreadPostIQDataPtr inp(new DemodulatorThreadPostIQData);    // push dummy to nudge queue
-    
-    //VSO: blocking push
-    iqInputQueue->push(inp);
 }
 
 bool DemodulatorThread::isMuted() {

src/demod/DemodulatorWorkerThread.cpp

@@ -116,6 +116,4 @@ void DemodulatorWorkerThread::run() {
 
 void DemodulatorWorkerThread::terminate() {
     IOThread::terminate();
-    DemodulatorWorkerThreadCommand inp;    // push dummy to nudge queue
-    commandQueue->push(inp);
 }

src/demod/DemodulatorWorkerThread.h

@@ -33,8 +33,6 @@ public:
     msresamp_crcf iqResampler;
     double iqResampleRatio;
 
-    DemodulatorThread *demodThread;
-
     long long sampleRate;
     unsigned int bandwidth;
     Modem *modem;

src/sdr/SDRPostThread.cpp

@@ -235,9 +235,6 @@ void SDRPostThread::run() {
 
 void SDRPostThread::terminate() {
     IOThread::terminate();
-    SDRThreadIQDataPtr dummy(new SDRThreadIQData);
-    //VSO: blocking push
-    iqDataInQueue->push(dummy);
 }
 
 void SDRPostThread::runSingleCH(SDRThreadIQData *data_in) {