diff --git a/DSView/pv/data/decoderstack.cpp b/DSView/pv/data/decoderstack.cpp
index ed777d4b..1600d390 100755
--- a/DSView/pv/data/decoderstack.cpp
+++ b/DSView/pv/data/decoderstack.cpp
@@ -388,7 +388,7 @@ void DecoderStack::stop_decode_work()
 {  
     //set the flag to exit from task thread 
      if (_stask_stauts){
-         _stask_stauts->m_bStop = true;
+         _stask_stauts->_bStop = true;
      }
     _decode_state = Stopped; 
 }
@@ -407,10 +407,11 @@ void DecoderStack::do_decode_work()
 {
     //set the flag to exit from task thread 
      if (_stask_stauts){
-         _stask_stauts->m_bStop = true;
+         _stask_stauts->_bStop = true;
      }
      _stask_stauts = new decode_task_status();
-     _stask_stauts->m_bStop = false;
+     _stask_stauts->_bStop = false;
+     _stask_stauts->_decoder = this;
      _decoder_status->clear(); //clear old items
   
     pv::view::LogicSignal *logic_signal = NULL;
@@ -514,7 +515,7 @@ void DecoderStack::decode_data(const uint64_t decode_start, const uint64_t decod
         qDebug()<<"decode data index have been end:"<<i;
     }
   
-    while(i < decode_end && !_no_memory && !status->m_bStop)
+    while(i < decode_end && !_no_memory && !status->_bStop)
     {
         std::vector<const uint8_t *> chunk;
         std::vector<uint8_t> chunk_const;
@@ -637,8 +638,11 @@ void DecoderStack::execute_decode_stack()
 	srd_session_metadata_set(session, SRD_CONF_SAMPLERATE,
 		g_variant_new_uint64((uint64_t)_samplerate));
 
-	srd_pd_output_callback_add(session, SRD_OUTPUT_ANN,
-		DecoderStack::annotation_callback, this);
+	srd_pd_output_callback_add(
+                    session, 
+                    SRD_OUTPUT_ANN,
+		            DecoderStack::annotation_callback,
+                    _stask_stauts);
 
     char *error = NULL;
     if (srd_session_start(session, &error) == SRD_OK)
@@ -668,13 +672,24 @@ uint64_t DecoderStack::sample_rate()
 }
 
 //the decode callback, annotation object will be create
-void DecoderStack::annotation_callback(srd_proto_data *pdata, void *decoder)
+void DecoderStack::annotation_callback(srd_proto_data *pdata, void *self)
 {
 	assert(pdata);
-	assert(decoder);
+	assert(self);
 
-	DecoderStack *const d = (DecoderStack*)decoder;
+    struct decode_task_status *st = (decode_task_status*)self;
+
+	DecoderStack *const d = st->_decoder;
 	assert(d);
+
+    if (st->_bStop){
+        qDebug()<<"decode task was stoped.";
+        return;
+    }
+    if (d->_decoder_status == NULL){
+        qDebug()<<"decode task was deleted.";
+        assert(false);
+    }
   
     if (d->_no_memory) {
         return;
diff --git a/DSView/pv/data/decoderstack.h b/DSView/pv/data/decoderstack.h
index 28ca7540..d5e0c18a 100755
--- a/DSView/pv/data/decoderstack.h
+++ b/DSView/pv/data/decoderstack.h
@@ -35,11 +35,6 @@
 #include "decode/decoderstatus.h"
  
 
-struct decode_task_status
-{  
-    volatile bool m_bStop;
-};
-
 namespace DecoderStackTest {
 class TwoDecoderStack;
 }
@@ -63,6 +58,13 @@ class RowData;
 }
 
 class Logic;
+class DecoderStack;
+
+struct decode_task_status
+{  
+    volatile bool _bStop;
+    DecoderStack *_decoder;
+};
 
  //a torotocol have a DecoderStack, destroy by DecodeTrace
 class DecoderStack : public QObject, public SignalData
@@ -163,7 +165,7 @@ public:
 private:
     void decode_data(const uint64_t decode_start, const uint64_t decode_end, srd_session *const session);
 	void execute_decode_stack();
-	static void annotation_callback(srd_proto_data *pdata, void *decoder);
+	static void annotation_callback(srd_proto_data *pdata, void *self);
     void do_decode_work();
   
 signals:
diff --git a/DSView/pv/data/logicsnapshot.cpp b/DSView/pv/data/logicsnapshot.cpp
index be0aab80..c342dba6 100755
--- a/DSView/pv/data/logicsnapshot.cpp
+++ b/DSView/pv/data/logicsnapshot.cpp
@@ -113,7 +113,12 @@ void LogicSnapshot::capture_ended()
         uint64_t index0 = block_index / RootScale;
         uint64_t index1 = block_index % RootScale;
         int order = 0;
+
         for(auto& iter:_ch_data) {
+            if (iter[index0].lbp[index1] == NULL){
+                assert(false);
+            }
+
             const uint64_t *end_ptr = (uint64_t *)iter[index0].lbp[index1] + (LeafBlockSamples / Scale);
             uint64_t *ptr = (uint64_t *)iter[index0].lbp[index1] + block_offset;
             while (ptr < end_ptr)
diff --git a/DSView/pv/sigsession.cpp b/DSView/pv/sigsession.cpp
index 0c2006fb..da710a2f 100755
--- a/DSView/pv/sigsession.cpp
+++ b/DSView/pv/sigsession.cpp
@@ -125,14 +125,7 @@ DevInst* SigSession::get_device()
 {
     return _dev_inst;
 }
-
-void SigSession::deselect_device()
-{ 
-    RELEASE_ARRAY(_decode_traces);
-    RELEASE_ARRAY(_group_traces);
-    _dev_inst = NULL;
-}
-
+ 
 /*
   when be called, it will call 4DSL lib sr_session_new, and create a session struct in the lib
 */
@@ -142,20 +135,18 @@ void SigSession::set_device(DevInst *dev_inst)
     
     assert(dev_inst);
 
-     if (_dev_inst){
-        _dev_inst->dev_inst();
-     }
+    clear_all_decoder(false);
 
+    RELEASE_ARRAY(_group_traces);
+ 
     if (_dev_inst) {
         sr_session_datafeed_callback_remove_all();
         _dev_inst->release();
+        _dev_inst = NULL;
     }
 
     _dev_inst = dev_inst;
-
-    RELEASE_ARRAY(_decode_traces);
-    RELEASE_ARRAY(_group_traces);
-
+ 
     if (_dev_inst) {
         try {
             _dev_inst->use(this);
@@ -179,8 +170,18 @@ void SigSession::set_device(DevInst *dev_inst)
 void SigSession::set_file(QString name)
 {
     // Deslect the old device, because file type detection in File::create
-    // destorys the old session inside libsigrok.
-    deselect_device();
+    // destorys the old session inside libsigrok.    
+  
+    clear_all_decoder(false);
+
+    RELEASE_ARRAY(_group_traces);
+     
+    //File::create(name) will get resource, so try to release old file before
+    if (_dev_inst) {
+        sr_session_datafeed_callback_remove_all();
+        _dev_inst->release();
+        _dev_inst = NULL;
+    }
 
     try {
         set_device(device::File::create(name));
@@ -196,6 +197,7 @@ void SigSession::close_file(DevInst *dev_inst)
     assert(_device_manager);
 
     try {
+        clear_all_decoder();
         dev_inst->device_updated();
         set_repeating(false);
         stop_capture();
@@ -500,13 +502,6 @@ void SigSession::sample_thread_proc(DevInst *dev_inst)
 }
 
 void SigSession::stop_capture()
-{
-    do_stop_capture();
-    int dex = 0;
-    clear_all_decode_task(dex);
-}
-
-void SigSession::do_stop_capture()
 {
     data_unlock(); 
 
@@ -517,7 +512,7 @@ void SigSession::do_stop_capture()
     // Check that sampling stopped
     if (_sampling_thread.joinable()){
         _sampling_thread.join();
-    }
+    }   
 }
 
 bool SigSession::get_capture_status(bool &triggered, int &progress)
@@ -689,7 +684,7 @@ void SigSession::init_signals()
 
 
     // Clear the decode traces 
-    RELEASE_ARRAY(_decode_traces);
+    clear_all_decoder();
 
     // Detect what data types we will receive
     if(_dev_inst) {
@@ -1786,7 +1781,7 @@ void SigSession::set_stop_scale(float scale)
 
      _bClose = true;
  
-     do_stop_capture(); //stop capture
+     stop_capture(); //stop capture
 
      clear_all_decoder(); //clear all decode task, and stop decode thread
 
@@ -1841,7 +1836,7 @@ void SigSession::set_stop_scale(float scale)
      trace->decoder()->stop_decode_work();
  }
 
- void SigSession::clear_all_decoder()
+ void SigSession::clear_all_decoder(bool bUpdateView)
  {
      //create the wait task deque
      int dex = -1;
@@ -1868,8 +1863,9 @@ void SigSession::set_stop_scale(float scale)
          _decode_thread.join();
      }
 
-     if (!is_closed())
-        signals_changed();
+     if (!is_closed() && bUpdateView){
+         signals_changed();
+     }        
  }
 
  void SigSession::clear_all_decode_task(int &runningDex)
diff --git a/DSView/pv/sigsession.h b/DSView/pv/sigsession.h
index 5623ed18..73445000 100755
--- a/DSView/pv/sigsession.h
+++ b/DSView/pv/sigsession.h
@@ -134,7 +134,7 @@ public:
 	 * Sets device instance that will be used in the next capture session.
 	 */
     void set_device(DevInst *dev_inst);
-    void deselect_device();
+   
     void set_file(QString name);
     void close_file(DevInst *dev_inst);
     void set_default_device();
@@ -232,7 +232,7 @@ public:
     sr_dev_inst* get_dev_inst_c();
     void Open();
     void Close();
-    void clear_all_decoder(); 
+    void clear_all_decoder(bool bUpdateView = true); 
 
     inline bool is_closed(){
         return _bClose;
@@ -293,8 +293,7 @@ private:
     void decode_task_proc();
     view::DecodeTrace* get_top_decode_task();    
 
-    void capture_init();
-    void do_stop_capture();
+    void capture_init(); 
     void data_lock();
     void data_unlock();
     void nodata_timeout();
diff --git a/DSView/pv/view/view.cpp b/DSView/pv/view/view.cpp
index 04ce8051..9c9b0f94 100755
--- a/DSView/pv/view/view.cpp
+++ b/DSView/pv/view/view.cpp
@@ -740,7 +740,12 @@ void View::signals_changed()
         const double height = (_time_viewport->height()
                                - 2 * actualMargin * label_size) * 1.0 / total_rows;
 
-        if (_session->get_device()->dev_inst()->mode == LOGIC) {
+        auto dev = _session->get_device();
+        assert(dev);
+        auto ins = dev->dev_inst();
+        assert(ins);
+
+        if (ins->mode == LOGIC) {
             GVariant* gvar = _session->get_device()->get_config(NULL, NULL, SR_CONF_MAX_HEIGHT_VALUE);
             if (gvar != NULL) {
                 max_height = (g_variant_get_byte(gvar) + 1) * MaxHeightUnit;