ENH: support AbortGenerateData in virtual streamer

Modules/Core/Streaming/include/otbStreamingImageVirtualWriter.h

@@ -142,6 +142,11 @@ public:
    *  This filter does not produce an output */
   void Update() ITK_OVERRIDE;
 
+  // the interface of the superclass getter function is not thread safe
+  bool GetAbortGenerateDataMutex() const;
+
+  void SetAbortGenerateData(bool val) override;
+
 protected:
   StreamingImageVirtualWriter();
 
@@ -186,6 +191,9 @@ private:
 
   bool          m_IsObserving;
   unsigned long m_ObserverID;
+
+  /** Lock to ensure thread-safety (added for the AbortGenerateData flag) */
+  itk::SimpleFastMutexLock m_Lock;
 };
 
 } // end namespace otb

Modules/Core/Streaming/include/otbStreamingImageVirtualWriter.txx

@@ -238,7 +238,7 @@ StreamingImageVirtualWriter<TInputImage>
    */
   InputImageRegionType streamRegion;
   for (m_CurrentDivision = 0;
-       m_CurrentDivision < m_NumberOfDivisions && !this->GetAbortGenerateData();
+       m_CurrentDivision < m_NumberOfDivisions && !this->GetAbortGenerateDataMutex();
        m_CurrentDivision++, m_DivisionProgress = 0, this->UpdateFilterProgress())
     {
     streamRegion = m_StreamingManager->GetSplit(m_CurrentDivision);
@@ -255,10 +255,17 @@ StreamingImageVirtualWriter<TInputImage>
    * If we ended due to aborting, push the progress up to 1.0 (since
    * it probably didn't end there)
    */
-  if (!this->GetAbortGenerateData())
+  if (!this->GetAbortGenerateDataMutex())
     {
     this->UpdateProgress(1.0);
     }
+  else
+    {
+    itk::ProcessAborted e(__FILE__, __LINE__);
+    e.SetLocation(ITK_LOCATION);
+    e.SetDescription("Image streaming has been aborted");
+    throw e;
+    }
 
   // Notify end event observers
   this->InvokeEvent(itk::EndEvent());
@@ -286,6 +293,26 @@ StreamingImageVirtualWriter<TInputImage>
   this->ReleaseInputs();
 }
 
+template <class TInputImage>
+bool
+StreamingImageVirtualWriter<TInputImage>
+::GetAbortGenerateDataMutex() const
+{
+  m_Lock.Lock();
+  bool ret = Superclass::GetAbortGenerateData();
+  m_Lock.Unlock();
+  return ret;
+}
+
+template <class TInputImage>
+void
+StreamingImageVirtualWriter<TInputImage>
+::SetAbortGenerateData(bool val)
+{
+  m_Lock.Lock();
+  Superclass::SetAbortGenerateData(val);
+  m_Lock.Unlock();
+}
 
 } // end namespace otb