diff --git a/src/AppFrame.cpp b/src/AppFrame.cpp
index ca5a8c1..6abd434 100644
--- a/src/AppFrame.cpp
+++ b/src/AppFrame.cpp
@@ -1612,6 +1612,9 @@ void AppFrame::OnIdle(wxIdleEvent& event) {
         updateDeviceParams();
     }
     
+    //try to garbage collect the retired demodulators.
+    wxGetApp().getDemodMgr().garbageCollect();
+
     DemodulatorInstance *demod = wxGetApp().getDemodMgr().getLastActiveDemodulator();
 
     if (demod && demod->isModemInitialized()) {
diff --git a/src/IOThread.cpp b/src/IOThread.cpp
index 029fe73..074af53 100644
--- a/src/IOThread.cpp
+++ b/src/IOThread.cpp
@@ -4,9 +4,6 @@
 #include "IOThread.h"
 #include <typeinfo>
 
-std::mutex ReBufferGC::g_mutex;
-std::set<ReferenceCounter *> ReBufferGC::garbage;
-
 #define SPIN_WAIT_SLEEP_MS 5
 
 IOThread::IOThread() {
@@ -130,7 +127,7 @@ bool IOThread::isTerminated(int waitMs) {
         }
     }
 
-    std::cout << "ERROR: thread '" << typeid(*this).name() << "' has not terminated in time ! (> " << waitMs << " ms)" << std::endl;
+    std::cout << "ERROR: thread '" << typeid(*this).name() << "' has not terminated in time ! (> " << waitMs << " ms)" << std::endl << std::flush;
 
     return terminated.load();
 }
diff --git a/src/IOThread.h b/src/IOThread.h
index 46ce897..3449ae2 100644
--- a/src/IOThread.h
+++ b/src/IOThread.h
@@ -5,13 +5,14 @@
 
 #include <mutex>
 #include <atomic>
-#include <deque>
+#include <vector>
 #include <map>
 #include <set>
 #include <string>
 #include <iostream>
 #include <thread>
-
+#include <memory>
+#include <climits>
 #include "ThreadBlockingQueue.h"
 #include "Timer.h"
 
@@ -23,163 +24,122 @@ struct map_string_less : public std::binary_function<std::string,std::string,boo
     }
 };
 
-
-class ReferenceCounter {
-
+template <typename PtrType>
+class ReBufferAge {
 public:
+    PtrType ptr;
+    int age;
 
-    //default constructor, initialized with refcont 1, sounds very natural
-    ReferenceCounter() {
-        refCount = 1;
-    }
-    
-//    void setIndex(int idx) {
-//        std::lock_guard < std::recursive_mutex > lock(m_mutex);
-//        index = idx;
-//    }
-
-//    int getIndex() {
-//        std::lock_guard < std::recursive_mutex > lock(m_mutex);
-//        return index;
-//    }
-
-    void setRefCount(int rc) {
-        std::lock_guard < std::recursive_mutex > lock(m_mutex);
-        refCount = rc;
-    }
-    
-    void decRefCount() {
-        std::lock_guard < std::recursive_mutex > lock(m_mutex);
-        refCount--;
-    }
-    
-    int getRefCount() {
-        std::lock_guard < std::recursive_mutex > lock(m_mutex);
-        return refCount;
-    }
-
-    // Access to the own mutex protecting the ReferenceCounter, i.e the monitor of the class
-     std::recursive_mutex& getMonitor() const {
-        return m_mutex;
-    }
-
-protected:
-    //this is a basic mutex for all ReferenceCounter derivatives operations INCLUDING the counter itself for consistency !
-   mutable std::recursive_mutex m_mutex;
-
-private:
-   int refCount;
-//   int index;
+    virtual ~ReBufferAge() {};
 };
 
-
 #define REBUFFER_GC_LIMIT 100
+#define REBUFFER_WARNING_THRESHOLD 150
 
-class ReBufferGC {
-public:
-    static void garbageCollect() {
-        std::lock_guard < std::mutex > lock(g_mutex);
-        
-        std::deque<ReferenceCounter *> garbageRemoval;
-        for (typename std::set<ReferenceCounter *>::iterator i = garbage.begin(); i != garbage.end(); i++) {
-            if ((*i)->getRefCount() <= 0) {
-                garbageRemoval.push_back(*i);
-            }
-            else {
-//                std::cout << "Garbage in queue buffer idx #" << (*i)->getIndex() << ", " << (*i)->getRefCount() << " usage(s)" << std::endl;
-                std::cout << "Garbage in queue buffer with " << (*i)->getRefCount() << " usage(s)" << std::endl;
-            }
-        }
-        if ( garbageRemoval.size() ) {
-            std::cout << "Garbage collecting " << garbageRemoval.size() << " ReBuffer(s)" << std::endl;
-            while (!garbageRemoval.empty()) {
-                ReferenceCounter *ref = garbageRemoval.back();
-                garbageRemoval.pop_back();
-                garbage.erase(ref);
-                delete ref;
-            }
-        }
-    }
-    
-    static void addGarbage(ReferenceCounter *ref) {
-        std::lock_guard < std::mutex > lock(g_mutex);
-        garbage.insert(ref);
-    }
-    
-private:
-    static std::mutex g_mutex;
-    static std::set<ReferenceCounter *> garbage;
-};
-
-
-template<class BufferType = ReferenceCounter>
+template<typename BufferType>
 class ReBuffer {
     
+    typedef typename std::shared_ptr<BufferType> ReBufferPtr;
+   
 public:
     ReBuffer(std::string bufferId) : bufferId(bufferId) {
-//        indexCounter.store(0);
     }
     
-    BufferType *getBuffer() {
+    /// Return a new ReBuffer_ptr usable by the application.
+    ReBufferPtr getBuffer() {
+
         std::lock_guard < std::mutex > lock(m_mutex);
 
-        BufferType* buf = nullptr;
-        for (outputBuffersI = outputBuffers.begin(); outputBuffersI != outputBuffers.end(); outputBuffersI++) {
-            if (buf == nullptr && (*outputBuffersI)->getRefCount() <= 0) {
-                buf = (*outputBuffersI);
-                buf->setRefCount(1);
-            } else if ((*outputBuffersI)->getRefCount() <= 0) {
-                (*outputBuffersI)->decRefCount();
+        // iterate the ReBuffer_ptr list: if the std::shared_ptr count == 1, it means 
+        //it is only referenced in outputBuffers itself, so available for re-use.
+        //else if the std::shared_ptr count <= 1, make it age.
+        //else the ReBuffer_ptr is in use, don't use it.
+
+        ReBufferPtr buf = nullptr;
+
+        outputBuffersI it = outputBuffers.begin();
+
+       while (it != outputBuffers.end()) {
+
+           long use = it->ptr.use_count();
+            //1. If we encounter a shared_ptr with a use count of 0, this
+            //is a bug since it is supposed to be at least 1, because it is referenced here.
+            //in this case, purge it from here and trace.
+            if (use == 0) {
+                it = outputBuffers.erase(it);
+                std::cout << "Warning: in ReBuffer '" << bufferId << "' count '" << outputBuffers.size() << "', found 1 dangling buffer !" << std::endl << std::flush;
+            } 
+            else if (use == 1) {
+                if (buf == nullptr) {
+                    it->age = 1;  //select this one.
+                    buf = it->ptr;
+                    //std::cout << "**" << std::flush;
+                    it++;
+                }
+                else {
+                    //make the other unused buffers age
+                    it->age--;
+                    it++;
+                }
             }
-        }
-        
-        if (buf != nullptr) {
-            if (outputBuffers.back()->getRefCount() < -REBUFFER_GC_LIMIT) {
-                BufferType *ref = outputBuffers.back();
+            else {
+                it++;
+            }
+        } //end while
+
+       //2.1 Garbage collect the oldest (last element) if it aged too much, and return the buffer
+       if (buf != nullptr) {
+            
+           if (outputBuffers.back().age < -REBUFFER_GC_LIMIT) {
+                //by the nature of the shared_ptr, memory will ne deallocated automatically.           
                 outputBuffers.pop_back();
-                delete ref;
+                //std::cout << "--" << std::flush;
             }
-//            buf->setIndex(indexCounter++);
             return buf;
         }
-        
-#define REBUFFER_WARNING_THRESHOLD 100
-        if (outputBuffers.size() > REBUFFER_WARNING_THRESHOLD) {
-            std::cout << "Warning: ReBuffer '" << bufferId << "' count '" << outputBuffers.size() << "' exceeds threshold of '" << REBUFFER_WARNING_THRESHOLD << "'" << std::endl;
-        }
 
-        //by default created with refcount = 1
-        buf = new BufferType();
-//        buf->setIndex(indexCounter++);
-        outputBuffers.push_back(buf);
+        if (outputBuffers.size() > REBUFFER_WARNING_THRESHOLD) {
+            std::cout << "Warning: ReBuffer '" << bufferId << "' count '" << outputBuffers.size() << "' exceeds threshold of '" << REBUFFER_WARNING_THRESHOLD << "'" << std::endl << std::flush;
+        }
         
-        return buf;
+        //3.We need to allocate a new buffer. 
+        ReBufferAge < ReBufferPtr > newBuffer;
+
+        //careful here: newBuffer.ptr is already constructed, so we need to set "in place" its
+        //ownership to a (new BufferType()).
+        newBuffer.ptr.reset(new BufferType());
+        newBuffer.age = 1;
+
+        outputBuffers.push_back(newBuffer);
+
+        //std::cout << "++" << std::flush;
+        
+        return newBuffer.ptr;
     }
     
+    /// Purge the cache.
     void purge() {
         std::lock_guard < std::mutex > lock(m_mutex);
-//        if (bufferId == "DemodulatorThreadBuffers") {
-//            std::cout << "'" << bufferId << "' purging.. total indexes: " << indexCounter.load() << std::endl;
-//        }
-        while (!outputBuffers.empty()) {
-            BufferType *ref = outputBuffers.front();
-            outputBuffers.pop_front();
-            if (ref->getRefCount() <= 0) {
-                delete ref;
-            } else {
-                // Something isn't done with it yet; throw it on the pile.. keep this as a bug indicator for now..
-                std::cout << "'" << bufferId << "' pushed garbage.." << std::endl;
-                ReBufferGC::addGarbage(ref);
-            }
-        }
+
+        // since outputBuffers are full std::shared_ptr,
+        //purging if will effectively loose the local reference,
+        // so the std::shared_ptr will naturally be deallocated
+        //when their time comes.  
+        outputBuffers.clear();
     }
 
-   private:
+private:
+
+    //name of the buffer cache kind
     std::string bufferId;
-    std::deque<BufferType*> outputBuffers;
-    typename std::deque<BufferType*>::iterator outputBuffersI;
+    
+    //the ReBuffer cache
+    std::vector< ReBufferAge < ReBufferPtr > > outputBuffers;
+
+    typedef typename std::vector< ReBufferAge < ReBufferPtr > >::iterator outputBuffersI;
+
+    //mutex protecting access to outputBuffers.
     mutable std::mutex m_mutex;
-//    std::atomic_int indexCounter;
 };
 
 
diff --git a/src/audio/AudioThread.cpp b/src/audio/AudioThread.cpp
index e0d4ad1..a96cf34 100644
--- a/src/audio/AudioThread.cpp
+++ b/src/audio/AudioThread.cpp
@@ -11,6 +11,8 @@
 #include <memory.h>
 #include <mutex>
 
+//50 ms
+#define HEARTBEAT_CHECK_PERIOD_MICROS (50 * 1000) 
 
 std::map<int, AudioThread *> AudioThread::deviceController;
 std::map<int, int> AudioThread::deviceSampleRate;
@@ -123,7 +125,7 @@ static int audioCallback(void *outputBuffer, void * /* inputBuffer */, unsigned
                     if (srcmix->currentInput->sampleRate == src->getSampleRate()) {
                         break;
                     }
-                    srcmix->currentInput->decRefCount();
+                   
                 }
                 srcmix->currentInput = nullptr;
             } //end while
@@ -140,7 +142,7 @@ static int audioCallback(void *outputBuffer, void * /* inputBuffer */, unsigned
             if (!srcmix->inputQueue->empty()) {
                 srcmix->audioQueuePtr = 0;
                 if (srcmix->currentInput) {
-                    srcmix->currentInput->decRefCount();
+                   
                     srcmix->currentInput = nullptr;
                 }
 
@@ -160,7 +162,7 @@ static int audioCallback(void *outputBuffer, void * /* inputBuffer */, unsigned
                 if (srcmix->audioQueuePtr >= srcmix->currentInput->data.size()) {
                     srcmix->audioQueuePtr = 0;
                     if (srcmix->currentInput) {
-                        srcmix->currentInput->decRefCount();
+                       
                         srcmix->currentInput = nullptr;
                     }
 
@@ -187,7 +189,7 @@ static int audioCallback(void *outputBuffer, void * /* inputBuffer */, unsigned
                 if (srcmix->audioQueuePtr >= srcmix->currentInput->data.size()) {
                     srcmix->audioQueuePtr = 0;
                     if (srcmix->currentInput) {
-                        srcmix->currentInput->decRefCount();
+                       
                         srcmix->currentInput = nullptr;
                     }
 
@@ -429,7 +431,9 @@ void AudioThread::run() {
     while (!stopping) {
         AudioThreadCommand command;
 
-        cmdQueue.pop(command);
+        if (!cmdQueue.pop(command, HEARTBEAT_CHECK_PERIOD_MICROS)) {
+            continue;
+        }
 
         if (command.cmd == AudioThreadCommand::AUDIO_THREAD_CMD_SET_DEVICE) {
             setupDevice(command.int_value);
@@ -444,20 +448,13 @@ void AudioThread::run() {
     std::lock_guard<std::recursive_mutex> lock(m_mutex);
 
     // Drain any remaining inputs, with a non-blocking pop
-    AudioThreadInput *ref;
-    while (inputQueue && inputQueue->try_pop(ref)) {
-       
-        if (ref) {
-            ref->decRefCount();
-        }
-    } //end while
+    if (inputQueue != nullptr) {
+        inputQueue->flush();
+    }
     
     //Nullify currentInput...
-    if (currentInput) {
-        currentInput->setRefCount(0);
-        currentInput = nullptr;
-    }
-
+    currentInput = nullptr;
+  
     //Stop 
     if (deviceController[parameters.deviceId] != this) {
         deviceController[parameters.deviceId]->removeThread(this);
@@ -494,7 +491,6 @@ void AudioThread::setActive(bool state) {
     
     std::lock_guard<std::recursive_mutex> lock(m_mutex);
 
-    AudioThreadInput *dummy;
     if (state && !active && inputQueue) {
         deviceController[parameters.deviceId]->bindThread(this);
     } else if (!state && active) {
@@ -504,12 +500,7 @@ void AudioThread::setActive(bool state) {
     // Activity state changing, clear any inputs
     if(inputQueue) {
 
-        while (inputQueue->try_pop(dummy)) {  // flush queue, non-blocking pop
-            
-            if (dummy) {
-                dummy->decRefCount();
-            }
-        }
+        inputQueue->flush();
     }
     active = state;
 }
diff --git a/src/audio/AudioThread.h b/src/audio/AudioThread.h
index ce349c0..119059e 100644
--- a/src/audio/AudioThread.h
+++ b/src/audio/AudioThread.h
@@ -8,12 +8,12 @@
 #include <map>
 #include <string>
 #include <atomic>
-
+#include <memory>
 #include "ThreadBlockingQueue.h"
 #include "RtAudio.h"
 #include "DemodDefs.h"
 
-class AudioThreadInput: public ReferenceCounter {
+class AudioThreadInput {
 public:
     long long frequency;
     int inputRate;
@@ -29,10 +29,12 @@ public:
     }
 
     ~AudioThreadInput() {
-        std::lock_guard < std::recursive_mutex > lock(m_mutex);
+       
     }
 };
 
+typedef std::shared_ptr<AudioThreadInput> AudioThreadInputPtr;
+
 class AudioThreadCommand {
 public:
     enum AudioThreadCommandEnum {
@@ -47,12 +49,12 @@ public:
     int int_value;
 };
 
-typedef ThreadBlockingQueue<AudioThreadInput *> AudioThreadInputQueue;
+typedef ThreadBlockingQueue<AudioThreadInputPtr> AudioThreadInputQueue;
 typedef ThreadBlockingQueue<AudioThreadCommand> AudioThreadCommandQueue;
 
 class AudioThread : public IOThread {
 public:
-    AudioThreadInput *currentInput;
+    AudioThreadInputPtr currentInput;
     AudioThreadInputQueue *inputQueue;
     std::atomic_uint audioQueuePtr;
     std::atomic_uint underflowCount;
diff --git a/src/demod/DemodDefs.h b/src/demod/DemodDefs.h
index d4a922a..ae6c239 100644
--- a/src/demod/DemodDefs.h
+++ b/src/demod/DemodDefs.h
@@ -9,6 +9,7 @@
 #include <vector>
 #include <atomic>
 #include <mutex>
+#include <memory>
 
 #include "IOThread.h"
 
@@ -29,7 +30,7 @@ public:
     std::string demodType;
 };
 
-class DemodulatorThreadIQData: public ReferenceCounter {
+class DemodulatorThreadIQData {
 public:
     long long frequency;
     long long sampleRate;
@@ -48,7 +49,7 @@ public:
         return *this;
     }
 
-    ~DemodulatorThreadIQData() {
+    virtual ~DemodulatorThreadIQData() {
 
     }
 };
@@ -56,7 +57,7 @@ public:
 class Modem;
 class ModemKit;
 
-class DemodulatorThreadPostIQData: public ReferenceCounter {
+class DemodulatorThreadPostIQData {
 public:
     std::vector<liquid_float_complex> data;
 
@@ -71,13 +72,13 @@ public:
 
     }
 
-    ~DemodulatorThreadPostIQData() {
-        std::lock_guard < std::recursive_mutex > lock(m_mutex);
+    virtual ~DemodulatorThreadPostIQData() {
+       
     }
 };
 
 
-class DemodulatorThreadAudioData: public ReferenceCounter {
+class DemodulatorThreadAudioData {
 public:
     long long frequency;
     unsigned int sampleRate;
@@ -95,11 +96,13 @@ public:
 
     }
 
-    ~DemodulatorThreadAudioData() {
+    virtual ~DemodulatorThreadAudioData() {
 
     }
 };
+typedef std::shared_ptr<DemodulatorThreadIQData> DemodulatorThreadIQDataPtr;
+typedef std::shared_ptr<DemodulatorThreadPostIQData> DemodulatorThreadPostIQDataPtr;
 
-typedef ThreadBlockingQueue<DemodulatorThreadIQData *> DemodulatorThreadInputQueue;
-typedef ThreadBlockingQueue<DemodulatorThreadPostIQData *> DemodulatorThreadPostInputQueue;
+typedef ThreadBlockingQueue< DemodulatorThreadIQDataPtr > DemodulatorThreadInputQueue;
+typedef ThreadBlockingQueue< DemodulatorThreadPostIQDataPtr > DemodulatorThreadPostInputQueue;
 typedef ThreadBlockingQueue<DemodulatorThreadControlCommand> DemodulatorThreadControlCommandQueue;
diff --git a/src/demod/DemodulatorInstance.cpp b/src/demod/DemodulatorInstance.cpp
index 355daa6..9605707 100644
--- a/src/demod/DemodulatorInstance.cpp
+++ b/src/demod/DemodulatorInstance.cpp
@@ -78,6 +78,7 @@ DemodulatorInstance::DemodulatorInstance() {
 }
 
 DemodulatorInstance::~DemodulatorInstance() {
+    std::lock_guard < std::mutex > lockData(m_thread_control_mutex);
 #if ENABLE_DIGITAL_LAB
     delete activeOutput;
 #endif
@@ -89,7 +90,7 @@ DemodulatorInstance::~DemodulatorInstance() {
     delete threadQueueControl;
     delete pipeAudioData;
     
-    wxGetApp().getBookmarkMgr().updateActiveList();
+   // wxGetApp().getBookmarkMgr().updateActiveList();
 }
 
 void DemodulatorInstance::setVisualOutputQueue(DemodulatorThreadOutputQueue *tQueue) {
@@ -97,6 +98,9 @@ void DemodulatorInstance::setVisualOutputQueue(DemodulatorThreadOutputQueue *tQu
 }
 
 void DemodulatorInstance::run() {
+
+    std::lock_guard < std::mutex > lockData(m_thread_control_mutex);
+
     if (active) {
         return;
     }
@@ -128,7 +132,7 @@ void DemodulatorInstance::run() {
 
     active = true;
 
-    wxGetApp().getBookmarkMgr().updateActiveList();
+ //   wxGetApp().getBookmarkMgr().updateActiveList();
 }
 
 void DemodulatorInstance::updateLabel(long long freq) {
@@ -166,7 +170,8 @@ void DemodulatorInstance::setLabel(std::string labelStr) {
 
 bool DemodulatorInstance::isTerminated() {
 
-    //
+    std::lock_guard < std::mutex > lockData(m_thread_control_mutex);
+
     bool audioTerminated = audioThread->isTerminated();
     bool demodTerminated = demodulatorThread->isTerminated();
     bool preDemodTerminated = demodulatorPreThread->isTerminated();
diff --git a/src/demod/DemodulatorInstance.h b/src/demod/DemodulatorInstance.h
index 749c6ec..a5be9d1 100644
--- a/src/demod/DemodulatorInstance.h
+++ b/src/demod/DemodulatorInstance.h
@@ -130,7 +130,7 @@ public:
     void closeOutput();
 #endif
         
-protected:
+private:
     DemodulatorThreadInputQueue* pipeIQInputData;
     DemodulatorThreadPostInputQueue* pipeIQDemodData;
     AudioThreadInputQueue *pipeAudioData;
@@ -138,7 +138,8 @@ protected:
     DemodulatorThread *demodulatorThread;
     DemodulatorThreadControlCommandQueue *threadQueueControl;
 
-private:
+    //protects child thread creation and termination 
+    mutable std::mutex m_thread_control_mutex;
 
     std::atomic<std::string *> label; //
     // User editable buffer, 16 bit string.
diff --git a/src/demod/DemodulatorMgr.cpp b/src/demod/DemodulatorMgr.cpp
index 4fa9e85..761a6b6 100644
--- a/src/demod/DemodulatorMgr.cpp
+++ b/src/demod/DemodulatorMgr.cpp
@@ -163,6 +163,7 @@ void DemodulatorMgr::deleteThread(DemodulatorInstance *demod) {
     demod->terminate();
 
     //Do not cleanup immediatly
+    std::lock_guard < std::mutex > lock_deleted(deleted_demods_busy);
     demods_deleted.push_back(demod);
 }
 
@@ -225,11 +226,7 @@ void DemodulatorMgr::setActiveDemodulator(DemodulatorInstance *demod, bool tempo
         }
 #endif
         wxGetApp().getBookmarkMgr().updateActiveList();
-    } else {
-        std::lock_guard < std::recursive_mutex > lock(demods_busy);
-        garbageCollect();
-        ReBufferGC::garbageCollect();
-    }
+    } 
 
     if (activeVisualDemodulator.load()) {
         activeVisualDemodulator.load()->setVisualOutputQueue(nullptr);
@@ -281,25 +278,29 @@ DemodulatorInstance *DemodulatorMgr::getLastDemodulatorWith(const std::string& t
 	return nullptr;
 }
 
-//Private internal method, no need to protect it with demods_busy
 void DemodulatorMgr::garbageCollect() {
-    if (demods_deleted.size()) {
+    
+    std::lock_guard < std::mutex > lock(deleted_demods_busy);
+
+    std::vector<DemodulatorInstance *>::iterator it = demods_deleted.begin();
+
+    while (it != demods_deleted.end()) {
+
+        if ((*it)->isTerminated()) {
+           
+            DemodulatorInstance *deleted = (*it);
       
-        std::vector<DemodulatorInstance *>::iterator i;
+            std::cout << "Garbage collected demodulator instance '" << deleted->getLabel() << "'... " << std::endl << std::flush;
+            demods_deleted.erase(it);
+            delete deleted;
 
-        for (i = demods_deleted.begin(); i != demods_deleted.end(); i++) {
-            if ((*i)->isTerminated()) {
-                DemodulatorInstance *deleted = (*i);
-                demods_deleted.erase(i);
-
-                std::cout << "Garbage collected demodulator instance " << deleted->getLabel() << std::endl;
-
-                delete deleted;
-                return;
-            }
+            //only garbage collect 1 demod at a time.
+            return;
         }
-      
-    }
+        else {
+            it++;
+        }
+    } //end while
 }
 
 void DemodulatorMgr::updateLastState() {
@@ -431,7 +432,6 @@ void DemodulatorMgr::saveInstance(DataNode *node, DemodulatorInstance *inst) {
             *settingsNode->newChild(msi->first.c_str()) = msi->second;
         }
     }
-
 }
 
 DemodulatorInstance *DemodulatorMgr::loadInstance(DataNode *node) {
diff --git a/src/demod/DemodulatorMgr.h b/src/demod/DemodulatorMgr.h
index ca65c22..e6887f1 100644
--- a/src/demod/DemodulatorMgr.h
+++ b/src/demod/DemodulatorMgr.h
@@ -67,10 +67,11 @@ public:
     void saveInstance(DataNode *node, DemodulatorInstance *inst);
 	
     DemodulatorInstance *loadInstance(DataNode *node);
+
+    //to be called periodically to cleanup removed demodulators.
+    void garbageCollect();
     
 private:
-    
-    void garbageCollect();
 
     std::vector<DemodulatorInstance *> demods;
     std::vector<DemodulatorInstance *> demods_deleted;
@@ -91,6 +92,8 @@ private:
     //protects access to demods lists and such, need to be recursive
     //because of the usage of public re-entrant methods 
     std::recursive_mutex demods_busy;
+
+    mutable std::mutex deleted_demods_busy;
     
     std::map<std::string, ModemSettings> lastModemSettings;
     std::map<int,RtAudio::DeviceInfo> outputDevices;
diff --git a/src/demod/DemodulatorPreThread.cpp b/src/demod/DemodulatorPreThread.cpp
index 574c7fa..f7a6217 100644
--- a/src/demod/DemodulatorPreThread.cpp
+++ b/src/demod/DemodulatorPreThread.cpp
@@ -12,6 +12,9 @@
 #include "CubicSDR.h"
 #include "DemodulatorInstance.h"
 
+//50 ms
+#define HEARTBEAT_CHECK_PERIOD_MICROS (50 * 1000) 
+
 DemodulatorPreThread::DemodulatorPreThread(DemodulatorInstance *parent) : IOThread(), iqResampler(NULL), iqResampleRatio(1), cModem(nullptr), cModemKit(nullptr), iqInputQueue(NULL), iqOutputQueue(NULL)
  {
 	initialized.store(false);
@@ -71,9 +74,11 @@ void DemodulatorPreThread::run() {
     t_Worker = new std::thread(&DemodulatorWorkerThread::threadMain, workerThread);
     
     while (!stopping) {
-        DemodulatorThreadIQData *inp;
+        DemodulatorThreadIQDataPtr inp;
 
-        iqInputQueue->pop(inp);
+        if (!iqInputQueue->pop(inp, HEARTBEAT_CHECK_PERIOD_MICROS)) {
+            continue;
+        }
         
         if (frequencyChanged.load()) {
             currentFrequency.store(newFrequency);
@@ -157,7 +162,7 @@ void DemodulatorPreThread::run() {
         }
 
         if (cModem && cModemKit && abs(shiftFrequency) > (int) ((double) (inp->sampleRate / 2) * 1.5)) {
-            inp->decRefCount();
+          
             continue;
         }
 
@@ -192,7 +197,7 @@ void DemodulatorPreThread::run() {
                 out_buf = temp_buf;
             }
 
-            DemodulatorThreadPostIQData *resamp = buffers.getBuffer();
+            DemodulatorThreadPostIQDataPtr resamp = buffers.getBuffer();
 
             size_t out_size = ceil((double) (bufSize) * iqResampleRatio) + 512;
 
@@ -218,8 +223,6 @@ void DemodulatorPreThread::run() {
             iqOutputQueue->push(resamp);   
         }
 
-        inp->decRefCount();
-
         DemodulatorWorkerThreadResult result;
         //process all worker results until 
         while (!stopping && workerResults->try_pop(result)) {
@@ -277,11 +280,8 @@ void DemodulatorPreThread::run() {
         }
     } //end while stopping
 
-    DemodulatorThreadPostIQData *tmp;
-    while (iqOutputQueue->try_pop(tmp)) {
-        
-        tmp->decRefCount();
-    }
+   
+    iqOutputQueue->flush();
     buffers.purge();
 }
 
@@ -348,7 +348,7 @@ int DemodulatorPreThread::getAudioSampleRate() {
 
 void DemodulatorPreThread::terminate() {
     IOThread::terminate();
-    DemodulatorThreadIQData *inp = new DemodulatorThreadIQData;    // push dummy to nudge queue
+    DemodulatorThreadIQDataPtr inp(new DemodulatorThreadIQData);    // push dummy to nudge queue
     
     //VSO: blocking push :
     iqInputQueue->push(inp);
diff --git a/src/demod/DemodulatorPreThread.h b/src/demod/DemodulatorPreThread.h
index 55bdfcd..88e6dff 100644
--- a/src/demod/DemodulatorPreThread.h
+++ b/src/demod/DemodulatorPreThread.h
@@ -17,7 +17,7 @@ class DemodulatorPreThread : public IOThread {
 public:
 
     DemodulatorPreThread(DemodulatorInstance *parent);
-    ~DemodulatorPreThread();
+    virtual ~DemodulatorPreThread();
 
     virtual void run();
     
diff --git a/src/demod/DemodulatorThread.cpp b/src/demod/DemodulatorThread.cpp
index a186404..5767c08 100644
--- a/src/demod/DemodulatorThread.cpp
+++ b/src/demod/DemodulatorThread.cpp
@@ -12,6 +12,9 @@
 #define M_PI        3.14159265358979323846
 #endif
 
+//50 ms
+#define HEARTBEAT_CHECK_PERIOD_MICROS (50 * 1000) 
+
 #ifdef __APPLE__
 #include <pthread.h>
 #endif
@@ -79,15 +82,16 @@ void DemodulatorThread::run() {
     ModemIQData modemData;
     
     while (!stopping) {
-        DemodulatorThreadPostIQData *inp;
-        
-        iqInputQueue->pop(inp);
-        //        std::lock_guard < std::mutex > lock(inp->m_mutex);
+        DemodulatorThreadPostIQDataPtr inp;
         
+        if (!iqInputQueue->pop(inp, HEARTBEAT_CHECK_PERIOD_MICROS)) {
+            continue;
+        }
+         
         size_t bufSize = inp->data.size();
         
         if (!bufSize) {
-            inp->decRefCount();
+           
             continue;
         }
         
@@ -104,7 +108,7 @@ void DemodulatorThread::run() {
         }
         
         if (!cModem || !cModemKit) {
-            inp->decRefCount();
+           
             continue;
         }
         
@@ -115,7 +119,7 @@ void DemodulatorThread::run() {
         modemData.sampleRate = inp->sampleRate;
         modemData.data.assign(inputData->begin(), inputData->end());
         
-        AudioThreadInput *ati = nullptr;
+        AudioThreadInputPtr ati = nullptr;
         
         ModemAnalog *modemAnalog = (cModem->getType() == "analog")?((ModemAnalog *)cModem):nullptr;
         ModemDigital *modemDigital = (cModem->getType() == "digital")?((ModemDigital *)cModem):nullptr;
@@ -133,7 +137,7 @@ void DemodulatorThread::run() {
             ati->data.resize(0);
         }
 
-        cModem->demodulate(cModemKit, &modemData, ati);
+        cModem->demodulate(cModemKit, &modemData, ati.get());
 
         double currentSignalLevel = 0;
         double sampleTime = double(inp->data.size()) / double(inp->sampleRate);
@@ -225,7 +229,6 @@ void DemodulatorThread::run() {
                 }
             }
         } else if (ati) {
-            ati->setRefCount(0);
             ati = nullptr;
         }
         
@@ -238,7 +241,7 @@ void DemodulatorThread::run() {
         }
 
         if ((ati || modemDigital) && localAudioVisOutputQueue != nullptr && localAudioVisOutputQueue->empty()) {
-            AudioThreadInput *ati_vis = new AudioThreadInput;
+            AudioThreadInputPtr ati_vis(new AudioThreadInput);
 
             ati_vis->sampleRate = inp->sampleRate;
             ati_vis->inputRate = inp->sampleRate;
@@ -246,7 +249,7 @@ void DemodulatorThread::run() {
             size_t num_vis = DEMOD_VIS_SIZE;
             if (modemDigital) {
                 if (ati) {  // TODO: handle digital modems with audio output
-                    ati->setRefCount(0);
+                   
                     ati = nullptr;
                 }
                 ati_vis->data.resize(inputData->size());
@@ -300,7 +303,7 @@ void DemodulatorThread::run() {
             
             if (!localAudioVisOutputQueue->try_push(ati_vis)) {
                 //non-blocking push needed for audio vis out
-                ati_vis->setRefCount(0);
+            
                 std::cout << "DemodulatorThread::run() cannot push ati_vis into localAudioVisOutputQueue, is full !" << std::endl;
                 std::this_thread::yield();
             }
@@ -310,12 +313,10 @@ void DemodulatorThread::run() {
             if (!muted.load() && (!wxGetApp().getSoloMode() || (demodInstance == wxGetApp().getDemodMgr().getLastActiveDemodulator()))) {
                 //non-blocking push needed for audio out
                 if (!audioOutputQueue->try_push(ati)) {
-                    ati->decRefCount();
+
                     std::cout << "DemodulatorThread::run() cannot push ati into audioOutputQueue, is full !" << std::endl;
                     std::this_thread::yield();
                 }
-            } else {
-                ati->setRefCount(0);
             }
         }
         
@@ -335,28 +336,12 @@ void DemodulatorThread::run() {
                     break;
             }
         }
-        
-        
-        inp->decRefCount();
     }
     // end while !stopping
     
     // Purge any unused inputs, with a non-blocking pop
-    DemodulatorThreadPostIQData *ref;
-    while (iqInputQueue->try_pop(ref)) {
-        
-        if (ref) {  // May have other consumers; just decrement
-            ref->decRefCount();
-        }
-    }
-
-    AudioThreadInput *ref_audio;
-    while (audioOutputQueue->try_pop(ref_audio)) {
-      
-        if (ref_audio) { // Originated here; set RefCount to 0
-            ref_audio->setRefCount(0);
-        }
-    }
+    iqInputQueue->flush();
+    audioOutputQueue->flush();
 
     outputBuffers.purge();
     
@@ -365,7 +350,7 @@ void DemodulatorThread::run() {
 
 void DemodulatorThread::terminate() {
     IOThread::terminate();
-    DemodulatorThreadPostIQData *inp = new DemodulatorThreadPostIQData;    // push dummy to nudge queue
+    DemodulatorThreadPostIQDataPtr inp(new DemodulatorThreadPostIQData);    // push dummy to nudge queue
     
     //VSO: blocking push
     iqInputQueue->push(inp);
diff --git a/src/demod/DemodulatorThread.h b/src/demod/DemodulatorThread.h
index 1df889c..5152364 100644
--- a/src/demod/DemodulatorThread.h
+++ b/src/demod/DemodulatorThread.h
@@ -10,7 +10,7 @@
 #include "AudioThread.h"
 #include "Modem.h"
 
-typedef ThreadBlockingQueue<AudioThreadInput *> DemodulatorThreadOutputQueue;
+typedef ThreadBlockingQueue<AudioThreadInputPtr> DemodulatorThreadOutputQueue;
 
 #define DEMOD_VIS_SIZE 2048
 #define DEMOD_SIGNAL_MIN -30
@@ -22,7 +22,7 @@ class DemodulatorThread : public IOThread {
 public:
 
     DemodulatorThread(DemodulatorInstance *parent);
-    ~DemodulatorThread();
+    virtual ~DemodulatorThread();
 
     void onBindOutput(std::string name, ThreadQueueBase *threadQueue);
     
diff --git a/src/demod/DemodulatorWorkerThread.cpp b/src/demod/DemodulatorWorkerThread.cpp
index b1304a7..b7e6daa 100644
--- a/src/demod/DemodulatorWorkerThread.cpp
+++ b/src/demod/DemodulatorWorkerThread.cpp
@@ -6,6 +6,9 @@
 #include "CubicSDR.h"
 #include <vector>
 
+//50 ms
+#define HEARTBEAT_CHECK_PERIOD_MICROS (50 * 1000) 
+
 DemodulatorWorkerThread::DemodulatorWorkerThread() : IOThread(),
         commandQueue(NULL), resultQueue(NULL), cModem(nullptr), cModemKit(nullptr) {
 }
@@ -31,7 +34,9 @@ void DemodulatorWorkerThread::run() {
         //we are waiting for the first command to show up (blocking!)
         //then consuming the commands until done. 
         while (!done) {
-            commandQueue->pop(command);
+            if (!commandQueue->pop(command, HEARTBEAT_CHECK_PERIOD_MICROS)) {
+                continue;
+            }
 
             switch (command.cmd) {
                 case DemodulatorWorkerThreadCommand::DEMOD_WORKER_THREAD_CMD_BUILD_FILTERS:
diff --git a/src/demod/DemodulatorWorkerThread.h b/src/demod/DemodulatorWorkerThread.h
index cb56176..0ebff7c 100644
--- a/src/demod/DemodulatorWorkerThread.h
+++ b/src/demod/DemodulatorWorkerThread.h
@@ -76,7 +76,7 @@ class DemodulatorWorkerThread : public IOThread {
 public:
 
     DemodulatorWorkerThread();
-    ~DemodulatorWorkerThread();
+    virtual ~DemodulatorWorkerThread();
 
     virtual void run();
 
diff --git a/src/forms/Bookmark/BookmarkView.cpp b/src/forms/Bookmark/BookmarkView.cpp
index 883b813..699ef9d 100644
--- a/src/forms/Bookmark/BookmarkView.cpp
+++ b/src/forms/Bookmark/BookmarkView.cpp
@@ -1411,7 +1411,7 @@ void BookmarkView::onEnterWindow( wxMouseEvent&  event ) {
     }
 #endif
 
-    setStatusText("You can mouse-drag a bookmark entry from one category to the next..etc. TODO: add more Bookmarks descriptions");
+    setStatusText("Drag & Drop to create / move bookmarks, Group and arrange bookmarks, quick Search by keywords.");
 }
 
 
diff --git a/src/modules/modem/Modem.h b/src/modules/modem/Modem.h
index a22166d..355f492 100644
--- a/src/modules/modem/Modem.h
+++ b/src/modules/modem/Modem.h
@@ -8,6 +8,7 @@
 #include "AudioThread.h"
 #include <cmath>
 #include <atomic>
+#include <memory>
 
 #define MIN_BANDWIDTH 500
 
@@ -25,7 +26,7 @@ public:
     int audioSampleRate;
 };
 
-class ModemIQData: public ReferenceCounter {
+class ModemIQData {
 public:
     std::vector<liquid_float_complex> data;
     long long sampleRate;
@@ -34,11 +35,13 @@ public:
         
     }
     
-    ~ModemIQData() {
-        std::lock_guard < std::recursive_mutex > lock(m_mutex);
+    virtual ~ModemIQData() {
+        
     }
 };
 
+typedef std::shared_ptr<ModemIQData> ModemIQDataPtr;
+
 // Copy of SoapySDR::Range, original comments
 class ModemRange
 {
diff --git a/src/modules/modem/analog/ModemAM.cpp b/src/modules/modem/analog/ModemAM.cpp
index 03da7e8..5c3604f 100644
--- a/src/modules/modem/analog/ModemAM.cpp
+++ b/src/modules/modem/analog/ModemAM.cpp
@@ -24,13 +24,13 @@ int ModemAM::getDefaultSampleRate() {
     return 6000;
 }
 
-void ModemAM::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut) {
+void ModemAM::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput* audioOut) {
     ModemKitAnalog *amkit = (ModemKitAnalog *)kit;
     
     initOutputBuffers(amkit,input);
     
     if (!bufSize) {
-        input->decRefCount();
+       
         return;
     }
     
diff --git a/src/modules/modem/analog/ModemDSB.cpp b/src/modules/modem/analog/ModemDSB.cpp
index 37f5b26..4c69c12 100644
--- a/src/modules/modem/analog/ModemDSB.cpp
+++ b/src/modules/modem/analog/ModemDSB.cpp
@@ -30,7 +30,7 @@ void ModemDSB::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *a
     initOutputBuffers(amkit, input);
     
     if (!bufSize) {
-        input->decRefCount();
+       
         return;
     }
     
diff --git a/src/modules/modem/analog/ModemFM.cpp b/src/modules/modem/analog/ModemFM.cpp
index da969b8..cf20709 100644
--- a/src/modules/modem/analog/ModemFM.cpp
+++ b/src/modules/modem/analog/ModemFM.cpp
@@ -29,7 +29,7 @@ void ModemFM::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *au
     initOutputBuffers(fmkit, input);
     
     if (!bufSize) {
-        input->decRefCount();
+      
         return;
     }
     
diff --git a/src/modules/modem/analog/ModemIQ.cpp b/src/modules/modem/analog/ModemIQ.cpp
index 9fa3ec7..81af37d 100644
--- a/src/modules/modem/analog/ModemIQ.cpp
+++ b/src/modules/modem/analog/ModemIQ.cpp
@@ -42,7 +42,7 @@ void ModemIQ::demodulate(ModemKit * /* kit */, ModemIQData *input, AudioThreadIn
     size_t bufSize = input->data.size();
     
     if (!bufSize) {
-        input->decRefCount();
+       
         return;
     }
     
diff --git a/src/modules/modem/analog/ModemLSB.cpp b/src/modules/modem/analog/ModemLSB.cpp
index 295a9c4..c3fb76d 100644
--- a/src/modules/modem/analog/ModemLSB.cpp
+++ b/src/modules/modem/analog/ModemLSB.cpp
@@ -46,7 +46,7 @@ void ModemLSB::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *a
     initOutputBuffers(akit,input);
     
     if (!bufSize) {
-        input->decRefCount();
+       
         return;
     }
     
diff --git a/src/modules/modem/analog/ModemNBFM.cpp b/src/modules/modem/analog/ModemNBFM.cpp
index fd1b255..84e3202 100644
--- a/src/modules/modem/analog/ModemNBFM.cpp
+++ b/src/modules/modem/analog/ModemNBFM.cpp
@@ -29,7 +29,7 @@ void ModemNBFM::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *
     initOutputBuffers(fmkit, input);
     
     if (!bufSize) {
-        input->decRefCount();
+       
         return;
     }
     
diff --git a/src/modules/modem/analog/ModemUSB.cpp b/src/modules/modem/analog/ModemUSB.cpp
index 775fadc..8b30761 100644
--- a/src/modules/modem/analog/ModemUSB.cpp
+++ b/src/modules/modem/analog/ModemUSB.cpp
@@ -46,7 +46,7 @@ void ModemUSB::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *a
     initOutputBuffers(akit,input);
     
     if (!bufSize) {
-        input->decRefCount();
+       
         return;
     }
     
diff --git a/src/process/FFTDataDistributor.cpp b/src/process/FFTDataDistributor.cpp
index 8636b70..07a6a3d 100644
--- a/src/process/FFTDataDistributor.cpp
+++ b/src/process/FFTDataDistributor.cpp
@@ -5,6 +5,9 @@
 #include <algorithm>
 #include <ThreadBlockingQueue.h>
 
+//50 ms
+#define HEARTBEAT_CHECK_PERIOD_MICROS (50 * 1000) 
+
 FFTDataDistributor::FFTDataDistributor() : outputBuffers("FFTDataDistributorBuffers"), fftSize(DEFAULT_FFT_SIZE), linesPerSecond(DEFAULT_WATERFALL_LPS), lineRateAccum(0.0) {
 
 }
@@ -28,8 +31,11 @@ void FFTDataDistributor::process() {
 		if (!isAnyOutputEmpty()) {
 			return;
 		}
-		DemodulatorThreadIQData *inp;
-		input->pop(inp);
+		DemodulatorThreadIQDataPtr inp;
+
+        if (!input->pop(inp, HEARTBEAT_CHECK_PERIOD_MICROS)) {
+            continue;
+        }
 
 		if (inp) {
             //Settings have changed, set new values and dump all previous samples stored in inputBuffer: 
@@ -73,7 +79,7 @@ void FFTDataDistributor::process() {
             memcpy(&inputBuffer.data[bufferOffset+bufferedItems],&inp->data[0], nbSamplesToAdd *sizeof(liquid_float_complex));
             bufferedItems += nbSamplesToAdd;
             //
-			inp->decRefCount();
+		
 		} else {
             //empty inp, wait for another.
 			continue;
@@ -105,7 +111,8 @@ void FFTDataDistributor::process() {
 
 					if (lineRateAccum >= 1.0) {
                         //each i represents a FFT computation
-						DemodulatorThreadIQData *outp = outputBuffers.getBuffer();
+                        DemodulatorThreadIQDataPtr outp = outputBuffers.getBuffer();
+
 						outp->frequency = inputBuffer.frequency;
 						outp->sampleRate = inputBuffer.sampleRate;
 						outp->data.assign(inputBuffer.data.begin()+bufferOffset+i,
diff --git a/src/process/ScopeVisualProcessor.cpp b/src/process/ScopeVisualProcessor.cpp
index 5b83b07..a1eefac 100644
--- a/src/process/ScopeVisualProcessor.cpp
+++ b/src/process/ScopeVisualProcessor.cpp
@@ -47,7 +47,7 @@ void ScopeVisualProcessor::process() {
     if (!isOutputEmpty()) {
         return;
     }
-    AudioThreadInput *audioInputData;
+    AudioThreadInputPtr audioInputData;
 
     if (input->try_pop(audioInputData)) {
           
@@ -56,11 +56,12 @@ void ScopeVisualProcessor::process() {
         }
         size_t i, iMax = audioInputData->data.size();
         if (!iMax) {
-            delete audioInputData; //->decRefCount();
+            //discard audioInputData.
+            audioInputData = nullptr;
             return;
         }
                 
-        ScopeRenderData *renderData = NULL;
+        ScopeRenderDataPtr renderData = nullptr;
         
         if (scopeEnabled) {
             iMax = audioInputData->data.size();
@@ -150,7 +151,7 @@ void ScopeVisualProcessor::process() {
             renderData->inputRate = audioInputData->inputRate;
             renderData->sampleRate = audioInputData->sampleRate;
             
-            delete audioInputData; //->decRefCount();
+            audioInputData = nullptr; //->decRefCount();
 
             double fft_ceil = 0, fft_floor = 1;
             
@@ -212,8 +213,6 @@ void ScopeVisualProcessor::process() {
             renderData->spectrum = true;
 
             distribute(renderData);
-        } else {
-            delete audioInputData; //->decRefCount();
-        }
+        } 
     } //end if try_pop()
 }
diff --git a/src/process/ScopeVisualProcessor.h b/src/process/ScopeVisualProcessor.h
index d5ba64c..25185be 100644
--- a/src/process/ScopeVisualProcessor.h
+++ b/src/process/ScopeVisualProcessor.h
@@ -6,8 +6,9 @@
 #include "VisualProcessor.h"
 #include "AudioThread.h"
 #include "ScopePanel.h"
+#include <memory>
 
-class ScopeRenderData: public ReferenceCounter {
+class ScopeRenderData {
 public:
 	std::vector<float> waveform_points;
     ScopePanel::ScopeMode mode = ScopePanel::SCOPE_MODE_Y;
@@ -17,9 +18,15 @@ public:
     bool spectrum;
     int fft_size;
     double fft_floor, fft_ceil;
+
+    virtual ~ScopeRenderData() {
+
+    }
 };
 
-typedef ThreadBlockingQueue<ScopeRenderData *> ScopeRenderDataQueue;
+typedef std::shared_ptr<ScopeRenderData> ScopeRenderDataPtr;
+
+typedef ThreadBlockingQueue<ScopeRenderDataPtr> ScopeRenderDataQueue;
 
 class ScopeVisualProcessor : public VisualProcessor<AudioThreadInput, ScopeRenderData> {
 public:
diff --git a/src/process/SpectrumVisualProcessor.cpp b/src/process/SpectrumVisualProcessor.cpp
index 7b02892..2e69fda 100644
--- a/src/process/SpectrumVisualProcessor.cpp
+++ b/src/process/SpectrumVisualProcessor.cpp
@@ -4,6 +4,8 @@
 #include "SpectrumVisualProcessor.h"
 #include "CubicSDR.h"
 
+//50 ms
+#define HEARTBEAT_CHECK_PERIOD_MICROS (50 * 1000) 
 
 SpectrumVisualProcessor::SpectrumVisualProcessor() : outputBuffers("SpectrumVisualProcessorBuffers") {
     lastInputBandwidth = 0;
@@ -192,22 +194,18 @@ void SpectrumVisualProcessor::process() {
         fftSizeChanged.store(false);
     }
 
-    DemodulatorThreadIQData *iqData;
+    DemodulatorThreadIQDataPtr iqData;
     
-    input->pop(iqData);
+    if (!input->pop(iqData, HEARTBEAT_CHECK_PERIOD_MICROS)) {
+        return;
+    }
     
     if (!iqData) {
         return;
     }
 
-   
-    //Start by locking concurrent access to iqData
-    std::lock_guard < std::recursive_mutex > lock(iqData->getMonitor());
-
     //then get the busy_lock
     std::lock_guard < std::mutex > busy_lock(busy_run);    
-
-
    
     bool doPeak = peakHold.load() && (peakReset.load() == 0);
     
@@ -246,7 +244,6 @@ void SpectrumVisualProcessor::process() {
         
         if (is_view.load()) {
             if (!iqData->sampleRate) {
-                iqData->decRefCount();
                
                 return;
             }
@@ -387,7 +384,7 @@ void SpectrumVisualProcessor::process() {
         }
         
         if (execute) {
-            SpectrumVisualData *output = outputBuffers.getBuffer();
+            SpectrumVisualDataPtr output = outputBuffers.getBuffer();
             
             if (output->spectrum_points.size() != fftSize * 2) {
                 output->spectrum_points.resize(fftSize * 2);
@@ -597,10 +594,7 @@ void SpectrumVisualProcessor::process() {
 
             distribute(output);
         }
-    }
- 
-    iqData->decRefCount();
-   
+    }  
     
     lastView = is_view.load();
 }
diff --git a/src/process/SpectrumVisualProcessor.h b/src/process/SpectrumVisualProcessor.h
index bef6490..3dcab2f 100644
--- a/src/process/SpectrumVisualProcessor.h
+++ b/src/process/SpectrumVisualProcessor.h
@@ -6,20 +6,24 @@
 #include "VisualProcessor.h"
 #include "DemodDefs.h"
 #include <cmath>
+#include <memory>
 
 #define SPECTRUM_VZM 2
 #define PEAK_RESET_COUNT 30
 
-class SpectrumVisualData : public ReferenceCounter {
+class SpectrumVisualData {
 public:
     std::vector<float> spectrum_points;
     std::vector<float> spectrum_hold_points;
     double fft_ceiling, fft_floor;
     long long centerFreq;
     int bandwidth;
+
+    virtual ~SpectrumVisualData() {};
 };
 
-typedef ThreadBlockingQueue<SpectrumVisualData *> SpectrumVisualDataQueue;
+typedef std::shared_ptr<SpectrumVisualData> SpectrumVisualDataPtr;
+typedef ThreadBlockingQueue<SpectrumVisualDataPtr> SpectrumVisualDataQueue;
 
 class SpectrumVisualProcessor : public VisualProcessor<DemodulatorThreadIQData, SpectrumVisualData> {
 public:
diff --git a/src/process/VisualProcessor.h b/src/process/VisualProcessor.h
index 7a9ee70..df1810a 100644
--- a/src/process/VisualProcessor.h
+++ b/src/process/VisualProcessor.h
@@ -9,11 +9,16 @@
 #include <algorithm>
 #include <vector>
 
-template<typename InputDataType = ReferenceCounter, typename OutputDataType = ReferenceCounter>
+template<typename InputDataType, typename OutputDataType>
 class VisualProcessor {
+    
     //
-    typedef  ThreadBlockingQueue<InputDataType*> VisualInputQueueType;
-    typedef  ThreadBlockingQueue<OutputDataType*> VisualOutputQueueType;
+    typedef std::shared_ptr<InputDataType> InputDataTypePtr;
+    typedef std::shared_ptr<OutputDataType> OutputDataTypePtr;
+
+    typedef  ThreadBlockingQueue<InputDataTypePtr> VisualInputQueueType;
+    typedef  ThreadBlockingQueue<OutputDataTypePtr> VisualOutputQueueType;
+
     typedef typename std::vector< VisualOutputQueueType *>::iterator outputs_i;
 public:
 	virtual ~VisualProcessor() {
@@ -96,22 +101,19 @@ protected:
     //available outputs, previously set by attachOutput().
     //* \param[in] timeout The number of microseconds to wait to push an item in each one of the outputs, 0(default) means indefinite wait.
     //* \param[in] errorMessage an error message written on std::cout in case pf push timeout.
-    void distribute(OutputDataType *item, std::uint64_t timeout = BLOCKING_INFINITE_TIMEOUT, const char* errorMessage = "") {
+    void distribute(OutputDataTypePtr item, std::uint64_t timeout = BLOCKING_INFINITE_TIMEOUT, const char* errorMessage = nullptr) {
       
         std::lock_guard < std::recursive_mutex > busy_lock(busy_update);
         //We will try to distribute 'output' among all 'outputs',
-        //so 'output' will a-priori be shared among all 'outputs' so set its ref count to this 
-        //amount.
-        item->setRefCount((int)outputs.size());
+        //so 'output' will a-priori be shared among all 'outputs'.
+        
         for (outputs_i it = outputs.begin(); it != outputs.end(); it++) {
-            //if 'output' failed to be given to an outputs_i, dec its ref count accordingly.
-            //blocking push, with a timeout
+            //'output' can fail to be given to an outputs_i,
+            //using a blocking push, with a timeout
         	if (!(*it)->push(item, timeout, errorMessage)) {
-                item->decRefCount();
+                //TODO : trace ?
         	} 
         }
-        // Now 'item' refcount matches the times 'item' has been successfully distributed,
-        //i.e shared among the outputs.
     }
 
     //the incoming data queue 
@@ -127,7 +129,7 @@ protected:
 //Specialization much like VisualDataReDistributor, except 
 //the input (pointer) is directly re-dispatched
 //to outputs, so that all output indeed SHARE the same instance. 
-template<typename OutputDataType = ReferenceCounter>
+template<typename OutputDataType>
 class VisualDataDistributor : public VisualProcessor<OutputDataType, OutputDataType> {
 protected:
     virtual void process() {
@@ -136,18 +138,14 @@ protected:
             
             if (!VisualProcessor<OutputDataType, OutputDataType>::isAnyOutputEmpty()) {
                 if (inp) {
-            	    inp->decRefCount();
+            	    //nothing
                 }
                 return;
             }
       
             if (inp) {
-                int previousRefCount = inp->getRefCount();
             	VisualProcessor<OutputDataType, OutputDataType>::distribute(inp);
-                //inp is now shared through the distribute(), which overwrite the previous ref count,
-                //so increment it properly.
-                int distributeRefCount = inp->getRefCount();
-                inp->setRefCount(previousRefCount + distributeRefCount);
+                //inp is now shared through the distribute() call.
             }
         }
     }
@@ -155,7 +153,7 @@ protected:
 
 //specialization class which process() take an input item and re-dispatch
 //A COPY to every outputs, without further processing. This is a 1-to-n dispatcher. 
-template<typename OutputDataType = ReferenceCounter>
+template<typename OutputDataType>
 class VisualDataReDistributor : public VisualProcessor<OutputDataType, OutputDataType> {
 protected:
     virtual void process() {
@@ -164,15 +162,17 @@ protected:
             
             if (!VisualProcessor<OutputDataType, OutputDataType>::isAnyOutputEmpty()) {
                 if (inp) {
-            	    inp->decRefCount();
+            	    //nothing
                 }
                 return;
             }
             
             if (inp) {
-                OutputDataType *outp = buffers.getBuffer();
+                OutputDataTypePtr outp = buffers.getBuffer();
+
+                //'deep copy' of the contents 
                 (*outp) = (*inp);
-                inp->decRefCount();
+  
                 VisualProcessor<OutputDataType, OutputDataType>::distribute(outp);
             }
         }
diff --git a/src/sdr/SDRPostThread.cpp b/src/sdr/SDRPostThread.cpp
index afefd60..fa9b38a 100644
--- a/src/sdr/SDRPostThread.cpp
+++ b/src/sdr/SDRPostThread.cpp
@@ -8,6 +8,9 @@
 #include <vector>
 #include <deque>
 
+//50 ms
+#define HEARTBEAT_CHECK_PERIOD_MICROS (50 * 1000) 
+
 SDRPostThread::SDRPostThread() : IOThread(), buffers("SDRPostThreadBuffers"), visualDataBuffers("SDRPostThreadVisualDataBuffers"), frequency(0) {
     iqDataInQueue = NULL;
     iqDataOutQueue = NULL;
@@ -183,23 +186,25 @@ void SDRPostThread::run() {
     iqActiveDemodVisualQueue = static_cast<DemodulatorThreadInputQueue*>(getOutputQueue("IQActiveDemodVisualDataOutput"));
     
     while (!stopping) {
-        SDRThreadIQData *data_in;
+        SDRThreadIQDataPtr data_in;
         
-        iqDataInQueue->pop(data_in);
+        if (!iqDataInQueue->pop(data_in, HEARTBEAT_CHECK_PERIOD_MICROS)) {
+            continue;
+        }
         //        std::lock_guard < std::mutex > lock(data_in->m_mutex);
 
         std::lock_guard < std::mutex > lock(busy_demod);
 
         if (data_in && data_in->data.size()) {
             if(data_in->numChannels > 1) {
-                runPFBCH(data_in);
+                runPFBCH(data_in.get());
             } else {
-                runSingleCH(data_in);
+                runSingleCH(data_in.get());
             }
         }
 
         if (data_in) {
-            data_in->decRefCount();   
+            //nothing
         }
 
         bool doUpdate = false;
@@ -217,9 +222,8 @@ void SDRPostThread::run() {
     } //end while
     
     //Be safe, remove as many elements as possible
-    DemodulatorThreadIQData *visualDataDummy;
-    while (iqVisualQueue && iqVisualQueue->try_pop(visualDataDummy)) {
-        visualDataDummy->decRefCount();        
+    if (iqVisualQueue) {
+        iqVisualQueue->flush();   
     }
 
     //    buffers.purge();
@@ -230,7 +234,7 @@ void SDRPostThread::run() {
 
 void SDRPostThread::terminate() {
     IOThread::terminate();
-    SDRThreadIQData *dummy = new SDRThreadIQData;
+    SDRThreadIQDataPtr dummy(new SDRThreadIQData);
     //VSO: blocking push
     iqDataInQueue->push(dummy);
 }
@@ -278,8 +282,8 @@ void SDRPostThread::runSingleCH(SDRThreadIQData *data_in) {
     }
     
     if (refCount) {
-        DemodulatorThreadIQData *demodDataOut = buffers.getBuffer();
-        demodDataOut->setRefCount(refCount);
+        DemodulatorThreadIQDataPtr demodDataOut = buffers.getBuffer();
+
         demodDataOut->frequency = frequency;
         demodDataOut->sampleRate = sampleRate;
         
@@ -333,7 +337,7 @@ void SDRPostThread::runPFBCH(SDRThreadIQData *data_in) {
     }
     
     if (iqDataOutQueue != NULL && !iqDataOutQueue->full()) {
-        DemodulatorThreadIQData *iqDataOut = visualDataBuffers.getBuffer();
+        DemodulatorThreadIQDataPtr iqDataOut = visualDataBuffers.getBuffer();
         
         bool doVis = false;
         
@@ -341,8 +345,6 @@ void SDRPostThread::runPFBCH(SDRThreadIQData *data_in) {
             doVis = true;
         }
         
-        iqDataOut->setRefCount(1 + (doVis?1:0));
-        
         iqDataOut->frequency = data_in->frequency;
         iqDataOut->sampleRate = data_in->sampleRate;
         iqDataOut->data.assign(data_in->data.begin(), data_in->data.begin() + dataSize);
@@ -407,8 +409,7 @@ void SDRPostThread::runPFBCH(SDRThreadIQData *data_in) {
                 continue;
             }
             
-            DemodulatorThreadIQData *demodDataOut = buffers.getBuffer();
-            demodDataOut->setRefCount(demodChannelActive[i] + doDemodVis);
+            DemodulatorThreadIQDataPtr demodDataOut = buffers.getBuffer();
             demodDataOut->frequency = chanCenters[i];
             demodDataOut->sampleRate = chanBw;
             
diff --git a/src/sdr/SoapySDRThread.cpp b/src/sdr/SoapySDRThread.cpp
index adb4eb9..a24fa98 100644
--- a/src/sdr/SoapySDRThread.cpp
+++ b/src/sdr/SoapySDRThread.cpp
@@ -207,17 +207,17 @@ void SDRThread::readStream(SDRThreadIQDataQueue* iqDataOutQueue) {
     //TODO: Add in doc the need to reduce SoapySDR device buffer length (if available) to restore higher fps.
 
     //0. Retreive a new batch 
-    SDRThreadIQData *dataOut = buffers.getBuffer();
+    SDRThreadIQDataPtr dataOut = buffers.getBuffer();
 
     //resize to the target size immedialetly, to minimize later reallocs:
-    assureBufferMinSize(dataOut, nElems);
+    assureBufferMinSize(dataOut.get(), nElems);
 
     //1.If overflow occured on the previous readStream(), transfer it in dataOut directly. 
     if (numOverflow > 0) {
         int n_overflow = std::min(numOverflow, nElems);
         
         //safety
-        assureBufferMinSize(dataOut, n_overflow);
+        assureBufferMinSize(dataOut.get(), n_overflow);
 
         ::memcpy(&dataOut->data[0], &overflowBuffer.data[0], n_overflow * sizeof(liquid_float_complex));
         n_read = n_overflow;
@@ -266,7 +266,7 @@ void SDRThread::readStream(SDRThreadIQDataQueue* iqDataOutQueue) {
             float *pp = (float *)buffs[0];
 
             //safety
-            assureBufferMinSize(dataOut, n_read + n_requested);
+            assureBufferMinSize(dataOut.get(), n_read + n_requested);
 
             if (iq_swap.load()) {
                 for (int i = 0; i < n_requested; i++) {
@@ -315,7 +315,7 @@ void SDRThread::readStream(SDRThreadIQDataQueue* iqDataOutQueue) {
             float *pp = (float *)buffs[0];
 
             //safety
-            assureBufferMinSize(dataOut, n_read + n_stream_read);
+            assureBufferMinSize(dataOut.get(), n_read + n_stream_read);
 
             if (iq_swap.load()) {
                 for (int i = 0; i < n_stream_read; i++) {
@@ -349,8 +349,7 @@ void SDRThread::readStream(SDRThreadIQDataQueue* iqDataOutQueue) {
         
         if (!iqDataOutQueue->try_push(dataOut)) {
             //The rest of the system saturates,
-            //finally the push didn't suceeded, recycle dataOut immediatly.
-            dataOut->setRefCount(0);
+            //finally the push didn't suceeded.
             
             std::cout << "SDRThread::readStream(): 3.2 iqDataOutQueue output queue is full, discard processing of the batch..." << std::endl;
 
@@ -359,7 +358,6 @@ void SDRThread::readStream(SDRThreadIQDataQueue* iqDataOutQueue) {
         }
     }
     else {
-        dataOut->setRefCount(0);
         std::cout << "SDRThread::readStream(): 3.1 iqDataOutQueue output queue is full, discard processing of the batch..." << std::endl;
         //saturation, let a chance to the other threads to consume the existing samples
         std::this_thread::yield();
diff --git a/src/sdr/SoapySDRThread.h b/src/sdr/SoapySDRThread.h
index e38077f..93fb381 100644
--- a/src/sdr/SoapySDRThread.h
+++ b/src/sdr/SoapySDRThread.h
@@ -4,7 +4,7 @@
 #pragma once
 
 #include <atomic>
-
+#include <memory>
 #include "ThreadBlockingQueue.h"
 #include "DemodulatorMgr.h"
 #include "SDRDeviceInfo.h"
@@ -17,7 +17,7 @@
 
 #include <stddef.h>
 
-class SDRThreadIQData: public ReferenceCounter {
+class SDRThreadIQData {
 public:
     long long frequency;
     long long sampleRate;
@@ -35,12 +35,12 @@ public:
 
     }
 
-    ~SDRThreadIQData() {
+    virtual ~SDRThreadIQData() {
 
     }
 };
-
-typedef ThreadBlockingQueue<SDRThreadIQData *> SDRThreadIQDataQueue;
+typedef std::shared_ptr<SDRThreadIQData> SDRThreadIQDataPtr;
+typedef ThreadBlockingQueue<SDRThreadIQDataPtr> SDRThreadIQDataQueue;
 
 class SDRThread : public IOThread {
 private:
diff --git a/src/util/ThreadBlockingQueue.h b/src/util/ThreadBlockingQueue.h
index d4e5588..cf8134c 100644
--- a/src/util/ThreadBlockingQueue.h
+++ b/src/util/ThreadBlockingQueue.h
@@ -3,7 +3,7 @@
 
 #pragma once 
 
-#include <vector>
+#include <deque>
 #include <mutex>
 #include <thread>
 #include <cstdint>
@@ -29,24 +29,22 @@ class ThreadQueueBase {
 template<typename T>
 class ThreadBlockingQueue : public ThreadQueueBase {
 
-    typedef typename std::vector<T>::value_type value_type;
-    typedef typename std::vector<T>::size_type size_type;
+    typedef typename std::deque<T>::value_type value_type;
+    typedef typename std::deque<T>::size_type size_type;
 
 public:
 
     /*! Create safe blocking queue. */
     ThreadBlockingQueue() {
-        //at least 1 (== Exchanger)
-        m_circular_buffer.resize(MIN_ITEM_NB); 
+        //at least 1 (== Java SynchronizedQueue)
+        m_max_num_items = MIN_ITEM_NB;
     };
     
     //Copy constructor
     ThreadBlockingQueue(const ThreadBlockingQueue& sq) {
         std::lock_guard < std::mutex > lock(sq.m_mutex);
-        m_circular_buffer = sq.m_circular_buffer;
-        m_head = sq.m_head;
-        m_tail = sq.m_tail;
-        m_size = sq.m_size;
+        m_queue = sq.m_queue;
+        m_max_num_items = sq.m_max_num_items;
     }
 
     /*! Destroy safe queue. */
@@ -62,11 +60,10 @@ public:
     void set_max_num_items(unsigned int max_num_items) {
         std::lock_guard < std::mutex > lock(m_mutex);
 
-        if (max_num_items > (unsigned int)m_circular_buffer.size()) {
+        if (max_num_items > m_max_num_items) {
             //Only raise the existing max size, never reduce it
             //for simplification sake at runtime.
-            m_circular_buffer.resize(max_num_items);
-            //m_head and m_tail stays valid for the new size.
+            m_max_num_items = max_num_items;
             m_cond_not_full.notify_all();
         }
     }
@@ -77,35 +74,34 @@ public:
      * \param[in] item An item.
      * \param[in] timeout a max waiting timeout in microseconds for an item to be pushed. 
      * by default, = 0 means indefinite wait.
-     * \param[in] errorMessage an error message written on std::cout in case of the timeout wait
+     * \param[in] errorMessage if != nullptr (is nullptr by default) an error message written on std::cout in case of the timeout wait
      * \return true if an item was pushed into the queue, else a timeout has occured.
      */
-    bool push(const value_type& item, std::uint64_t timeout = BLOCKING_INFINITE_TIMEOUT,const char* errorMessage = "") {
+    bool push(const value_type& item, std::uint64_t timeout = BLOCKING_INFINITE_TIMEOUT,const char* errorMessage = nullptr) {
         std::unique_lock < std::mutex > lock(m_mutex);
 
         if (timeout == BLOCKING_INFINITE_TIMEOUT) {
             m_cond_not_full.wait(lock, [this]() // Lambda funct
             {
-                return m_size < m_circular_buffer.size();
+                return m_queue.size() < m_max_num_items;
             });
-        } else if (timeout <= NON_BLOCKING_TIMEOUT && m_size >= m_circular_buffer.size()) {
+        } else if (timeout <= NON_BLOCKING_TIMEOUT && m_queue.size() >= m_max_num_items) {
             // if the value is below a threshold, consider it is a try_push()
             return false;
         }
         else if (false == m_cond_not_full.wait_for(lock, std::chrono::microseconds(timeout),
-           [this]() { return m_size < m_circular_buffer.size(); })) {
-            std::thread::id currentThreadId = std::this_thread::get_id();
-            std::cout << "WARNING: Thread 0x" << std::hex << currentThreadId << std::dec <<
-                " (" << currentThreadId << ") executing {" << typeid(*this).name() << "}.push() has failed with timeout > " <<
-                (timeout * 0.001) << " ms, message: " << errorMessage << std::endl;
-           return false;
+            [this]() { return m_queue.size() < m_max_num_items; })) {
+
+            if (errorMessage != nullptr) {
+                std::thread::id currentThreadId = std::this_thread::get_id();
+                std::cout << "WARNING: Thread 0x" << std::hex << currentThreadId << std::dec <<
+                    " (" << currentThreadId << ") executing {" << typeid(*this).name() << "}.push() has failed with timeout > " <<
+                    (timeout * 0.001) << " ms, message: " << errorMessage << std::endl << std::flush;
+            } 
+            return false;
         }
 
-        //m_tail is already the next valid place an item can be put
-        m_circular_buffer[m_tail] = item;
-        m_tail = nextIndex(m_tail, (int)m_circular_buffer.size());
-        m_size++;
-
+        m_queue.push_back(item);
         m_cond_not_empty.notify_all();
         return true;
     }
@@ -118,14 +114,11 @@ public:
     bool try_push(const value_type& item) {
         std::lock_guard < std::mutex > lock(m_mutex);
 
-        if (m_size >= m_circular_buffer.size()) {
+        if (m_queue.size() >= m_max_num_items) {
             return false;
         }
 
-        //m_tail is already the next valid place an item can be put
-        m_circular_buffer[m_tail] = item;
-        m_tail = nextIndex(m_tail, (int)m_circular_buffer.size());
-        m_size++;
+        m_queue.push_back(item);
         m_cond_not_empty.notify_all();
         return true;
     }
@@ -133,33 +126,35 @@ public:
     /**
      * Pops item from the queue. If the queue is empty, blocks for timeout microseconds, or until item becomes available.
      * \param[in] timeout The number of microseconds to wait. O (default) means indefinite wait.
-     * \param[in] errorMessage an error message written on std::cout in case of the timeout wait
+     * \param[in] errorMessage if != nullptr (is nullptr by default) an error message written on std::cout in case of the timeout wait
      * \return true if get an item from the queue, false if no item is received before the timeout.
      */
-    bool pop(value_type& item, std::uint64_t timeout = BLOCKING_INFINITE_TIMEOUT, const char* errorMessage = "") {
+    bool pop(value_type& item, std::uint64_t timeout = BLOCKING_INFINITE_TIMEOUT, const char* errorMessage = nullptr) {
         std::unique_lock < std::mutex > lock(m_mutex);
 
         if (timeout == BLOCKING_INFINITE_TIMEOUT) {
             m_cond_not_empty.wait(lock, [this]() // Lambda funct
             {
-                return m_size > 0;
+                return !m_queue.empty();
             });
-        } else if (timeout <= NON_BLOCKING_TIMEOUT && m_size == 0) {
+        } else if (timeout <= NON_BLOCKING_TIMEOUT && m_queue.empty()) {
             // if the value is below a threshold, consider it is try_pop()
             return false;
         }
         else if (false == m_cond_not_empty.wait_for(lock, std::chrono::microseconds(timeout),
-            [this]() { return m_size > 0; })) {
-            std::thread::id currentThreadId = std::this_thread::get_id();
-            std::cout << "WARNING: Thread 0x" << std::hex << currentThreadId << std::dec <<
-                " (" << currentThreadId << ") executing {" << typeid(*this).name() << "}.pop() has failed with timeout > " <<
-                (timeout * 0.001) << " ms, message: " << errorMessage << std::endl;
+            [this]() { return !m_queue.empty(); })) {
+
+            if (errorMessage != nullptr) {
+                std::thread::id currentThreadId = std::this_thread::get_id();
+                std::cout << "WARNING: Thread 0x" << std::hex << currentThreadId << std::dec <<
+                    " (" << currentThreadId << ") executing {" << typeid(*this).name() << "}.pop() has failed with timeout > " <<
+                    (timeout * 0.001) << " ms, message: " << errorMessage << std::endl << std::flush;
+            }
             return false;
         }
 
-        item = m_circular_buffer[m_head];
-        m_head = nextIndex(m_head, (int)m_circular_buffer.size());
-        m_size--;
+        item = m_queue.front();
+        m_queue.pop_front();
         m_cond_not_full.notify_all();
         return true;
     }
@@ -172,13 +167,12 @@ public:
     bool try_pop(value_type& item) {
         std::lock_guard < std::mutex > lock(m_mutex);
 
-        if (m_size == 0) {
+        if (m_queue.empty()) {
             return false;
         }
 
-        item = m_circular_buffer[m_head];
-        m_head = nextIndex(m_head, (int)m_circular_buffer.size());
-        m_size--;
+        item = m_queue.front();
+        m_queue.pop_front();
         m_cond_not_full.notify_all();
         return true;
     }
@@ -190,7 +184,7 @@ public:
      */
     size_type size() const {
         std::lock_guard < std::mutex > lock(m_mutex);
-        return m_size;
+        return m_queue.size();
     }
 
     /**
@@ -199,7 +193,7 @@ public:
      */
     bool empty() const {
         std::lock_guard < std::mutex > lock(m_mutex);
-        return m_size == 0;
+        return m_queue.empty();
     }
 
     /**
@@ -208,7 +202,7 @@ public:
      */
     bool full() const {
         std::lock_guard < std::mutex > lock(m_mutex);
-        return (m_size >= m_circular_buffer.size());
+        return (m_queue.size() >= m_max_num_items);
     }
 
     /**
@@ -216,9 +210,7 @@ public:
      */
     void flush() {
         std::lock_guard < std::mutex > lock(m_mutex);
-        m_head = 0;
-        m_tail = 0;
-        m_size = 0;
+        m_queue.clear();
         m_cond_not_full.notify_all();
     }
 
@@ -230,25 +222,22 @@ public:
         if (this != &sq) {
             std::lock_guard < std::mutex > lock1(m_mutex);
             std::lock_guard < std::mutex > lock2(sq.m_mutex);
-            m_circular_buffer.swap(sq.m_circular_buffer);
+            m_queue.swap(sq.m_queue);
+            std::swap(m_max_num_items, sq.m_max_num_items);
 
-            std::swap(m_head, sq.m_head);
-            std::swap(m_tail, sq.m_tail);
-            std::swap(m_size, sq.m_size);
-
-            if (m_size > 0) {
+            if (!m_queue.empty()) {
                 m_cond_not_empty.notify_all();
             }
 
-            if (sq.m_size > 0) {
+            if (!sq.m_queue.empty()) {
                 sq.m_cond_not_empty.notify_all();
             }
 
-            if (m_size < m_circular_buffer.size()) {
+            if (!m_queue.full()) {
                 m_cond_not_full.notify_all();
             }
 
-            if (sq.m_size < sq.m_circular_buffer.size()) {
+            if (!sq.m_queue.full()) {
                 sq.m_cond_not_full.notify_all();
             }
         }
@@ -260,17 +249,14 @@ public:
             std::lock_guard < std::mutex > lock1(m_mutex);
             std::lock_guard < std::mutex > lock2(sq.m_mutex);
   
-            m_circular_buffer = sq.m_circular_buffer;
+            m_queue = sq.m_queue;
+            m_max_num_items = sq.m_max_num_items;
 
-            m_head = sq.m_head;
-            m_tail = sq.m_tail;
-            m_size = sq.m_size;
-
-            if (m_size > 0) {
+            if (!m_queue.empty()) {
                 m_cond_not_empty.notify_all();
             }
 
-            if (m_size < m_circular_buffer.size()) {
+            if (!m_queue.full()) {
                 m_cond_not_full.notify_all();
             }
         }
@@ -278,27 +264,13 @@ public:
     }
 
 private:
-    /// use a circular buffer structure to prevent allocations / reallocations (fixed array + modulo)
-    std::vector<T> m_circular_buffer;
 
-    /**
-    * The 'head' index of the element at the head of the deque, 'tail'
-    * the next (valid !) index at which an element can be pushed.
-    * m_head == m_tail means empty.
-    */
-    int m_head = 0, m_tail = 0;
-
-    //hold the current number of elements.
-    size_type m_size = 0;
-
-    //
-    inline int nextIndex(int index, int mod) const {
-        return (index + 1 == mod) ? 0 : index + 1;
-    }
+    std::deque<T> m_queue;
 
     mutable std::mutex m_mutex;
     std::condition_variable m_cond_not_empty;
     std::condition_variable m_cond_not_full;
+    size_t m_max_num_items = MIN_ITEM_NB;
 };
 
 /*! Swaps the contents of two ThreadBlockingQueue objects. (external operator) */
diff --git a/src/visual/ScopeCanvas.cpp b/src/visual/ScopeCanvas.cpp
index 5371513..fa25b8a 100644
--- a/src/visual/ScopeCanvas.cpp
+++ b/src/visual/ScopeCanvas.cpp
@@ -104,7 +104,7 @@ void ScopeCanvas::OnPaint(wxPaintEvent& WXUNUSED(event)) {
     wxPaintDC dc(this);
     const wxSize ClientSize = GetClientSize();
     
-    ScopeRenderData *avData;
+    ScopeRenderDataPtr avData;
     while (inputData.try_pop(avData)) {
        
         
@@ -113,7 +113,7 @@ void ScopeCanvas::OnPaint(wxPaintEvent& WXUNUSED(event)) {
             if (avData->waveform_points.size()) {
                 scopePanel.setPoints(avData->waveform_points);
             }
-            avData->decRefCount();
+
         } else {
             if (avData->waveform_points.size()) {
                 spectrumPanel.setPoints(avData->waveform_points);
@@ -124,8 +124,7 @@ void ScopeCanvas::OnPaint(wxPaintEvent& WXUNUSED(event)) {
                 spectrumPanel.setFFTSize(avData->fft_size);
                 spectrumPanel.setShowDb(showDb);
             }
-            
-            avData->decRefCount();
+         
         }
     }
 
diff --git a/src/visual/SpectrumCanvas.cpp b/src/visual/SpectrumCanvas.cpp
index 742bb2c..abfc6f5 100644
--- a/src/visual/SpectrumCanvas.cpp
+++ b/src/visual/SpectrumCanvas.cpp
@@ -54,7 +54,7 @@ void SpectrumCanvas::OnPaint(wxPaintEvent& WXUNUSED(event)) {
     wxPaintDC dc(this);
     const wxSize ClientSize = GetClientSize();
     
-    SpectrumVisualData *vData;
+    SpectrumVisualDataPtr vData;
     if (visualDataQueue.try_pop(vData)) {
             
         if (vData) {
@@ -62,7 +62,6 @@ void SpectrumCanvas::OnPaint(wxPaintEvent& WXUNUSED(event)) {
             spectrumPanel.setPeakPoints(vData->spectrum_hold_points);
             spectrumPanel.setFloorValue(vData->fft_floor);
             spectrumPanel.setCeilValue(vData->fft_ceiling);
-            vData->decRefCount();
         }
     }
     
diff --git a/src/visual/WaterfallCanvas.cpp b/src/visual/WaterfallCanvas.cpp
index b75ca92..9d26d56 100644
--- a/src/visual/WaterfallCanvas.cpp
+++ b/src/visual/WaterfallCanvas.cpp
@@ -97,7 +97,7 @@ void WaterfallCanvas::processInputQueue() {
     if (linesPerSecond) {
         if (lpsIndex >= targetVis) {
             while (lpsIndex >= targetVis) {
-                SpectrumVisualData *vData;
+                SpectrumVisualDataPtr vData;
 
                 if (visualDataQueue.try_pop(vData)) {
                     
@@ -106,7 +106,7 @@ void WaterfallCanvas::processInputQueue() {
                             waterfallPanel.setPoints(vData->spectrum_points);
                         }
                         waterfallPanel.step();
-                        vData->decRefCount();
+                      
                         updated = true;
                     }
                     lpsIndex-=targetVis;
@@ -915,13 +915,7 @@ void WaterfallCanvas::setLinesPerSecond(int lps) {
     linesPerSecond = lps;
 
     //empty all
-    SpectrumVisualData *vData;
-    while (visualDataQueue.try_pop(vData)) {
-        
-        if (vData) {
-            vData->decRefCount();
-        }
-    }
+    visualDataQueue.flush();
 }
 
 void WaterfallCanvas::setMinBandwidth(int min) {