Replace signal-based abort handling by query-based handling

The abort handling is currently only used to process Ctrl-C from Matlab.
Since Matlab R2019a, it appears that calling utIsInterruptPending() from
a thread other than the main thread will crash. The previous approach of
checking utIsInterruptPending() in a thread, and then signalling the running
algorithm was therefore broken.

9 files changed, 19 insertions, 44 deletions

diff --git a/include/astra/Algorithm.h b/include/astra/Algorithm.h
index af9e41d..393baf0 100644
--- a/include/astra/Algorithm.h
+++ b/include/astra/Algorithm.h
@@ -93,26 +93,11 @@ public:
 	 */
 	virtual void setGPUIndex(int /*_iGPUIndex*/) { };
 
-	/** Signal the algorithm it should abort soon.
-	 *  This is intended to be called from a different thread
-	 *  while the algorithm is running. There are no guarantees
-	 *  on how soon the algorithm will abort. The state of the
-	 *  algorithm object will be consistent (so it is safe to delete it
-	 *  normally afterwards), but the algorithm's output is undefined.
-	 *
-	 *  Note that specific algorithms may give guarantees on their
-	 *  state after an abort. Check their documentation for details.
-	 */
-	virtual void signalAbort() { m_bShouldAbort = true; }
-
 protected:
 
 	//< Has this class been initialized?
 	bool m_bIsInitialized;
 
-	//< If this is set, the algorithm should try to abort as soon as possible.
-	volatile bool m_bShouldAbort;
-
 private:
 	/**
 	 * Private copy constructor to prevent CAlgorithms from being copied.
diff --git a/include/astra/AsyncAlgorithm.h b/include/astra/AsyncAlgorithm.h
index 0e43e67..6cb84bb 100644
--- a/include/astra/AsyncAlgorithm.h
+++ b/include/astra/AsyncAlgorithm.h
@@ -80,10 +80,6 @@ public:
 	 */
 	bool isDone() const { return m_bDone; }	
 
-	/** Signal abort to the wrapped algorithm. 
-	 */
-	void signalAbort();
-
 protected:
 	//< Has this class been initialized?
 	bool m_bInitialized;
diff --git a/include/astra/CudaCglsAlgorithm3D.h b/include/astra/CudaCglsAlgorithm3D.h
index 6f35192..63f028a 100644
--- a/include/astra/CudaCglsAlgorithm3D.h
+++ b/include/astra/CudaCglsAlgorithm3D.h
@@ -141,9 +141,6 @@ public:
 	 */
 	void setGPUIndex(int _iGPUIndex) { m_iGPUIndex = _iGPUIndex; }
 
-
-	virtual void signalAbort();
-
 	/** Get the norm of the residual image.
 	 *  Only a few algorithms support this method.
 	 *
diff --git a/include/astra/CudaReconstructionAlgorithm2D.h b/include/astra/CudaReconstructionAlgorithm2D.h
index 197f984..56f3b25 100644
--- a/include/astra/CudaReconstructionAlgorithm2D.h
+++ b/include/astra/CudaReconstructionAlgorithm2D.h
@@ -122,8 +122,6 @@ public:
 	 */
 	virtual void run(int _iNrIterations = 0);
 
-	virtual void signalAbort();
-
 protected:
 	
 	/** Check this object.
diff --git a/include/astra/CudaSirtAlgorithm3D.h b/include/astra/CudaSirtAlgorithm3D.h
index 9c041b9..dd3f749 100644
--- a/include/astra/CudaSirtAlgorithm3D.h
+++ b/include/astra/CudaSirtAlgorithm3D.h
@@ -155,9 +155,6 @@ public:
 	 */
 	void setGPUIndex(int _iGPUIndex) { m_iGPUIndex = _iGPUIndex; }
 
-
-	virtual void signalAbort();
-
 	/** Get the norm of the residual image.
 	 *  Only a few algorithms support this method.
 	 *
diff --git a/include/astra/Globals.h b/include/astra/Globals.h
index 993e443..a353940 100644
--- a/include/astra/Globals.h
+++ b/include/astra/Globals.h
@@ -150,6 +150,25 @@ namespace astra {
 	};
 }
 
+//----------------------------------------------------------------------------------------
+// functions for internal use
+
+namespace astra {
+
+/** Specify a function) to be called by shouldAbort() to check if an external
+ *  abort signal has arrived, or NULL to disable. Intended to be used by the
+ *  matlab/python interfaces to check if Ctrl-C has been pressed.
+ */
+void setShouldAbortHook(bool (*pShouldAbortHook)(void));
+
+/** Check if we should abort execution (due to an external signal).
+ */
+bool shouldAbort();
+}
+
+//----------------------------------------------------------------------------------------
+// functions for external use
+
 namespace astra {
 _AstraExport inline int getVersion() { return ASTRA_TOOLBOXVERSION; }
 _AstraExport inline const char* getVersionString() { return ASTRA_TOOLBOXVERSION_STRING; }
diff --git a/include/astra/cuda/2d/algo.h b/include/astra/cuda/2d/algo.h
index 2ce929c..3fccdef 100644
--- a/include/astra/cuda/2d/algo.h
+++ b/include/astra/cuda/2d/algo.h
@@ -56,8 +56,6 @@ public:
 
 	bool setSuperSampling(int raysPerDet, int raysPerPixelDim);
 
-	void signalAbort() { shouldAbort = true; }
-
 	virtual bool enableVolumeMask();
 	virtual bool enableSinogramMask();
 
@@ -137,8 +135,6 @@ protected:
 	SFanProjection* fanProjs;
 	float fOutputScale;
 
-	volatile bool shouldAbort;
-
 	bool freeGPUMemory;
 
 	// Input/output
diff --git a/include/astra/cuda/3d/algo3d.h b/include/astra/cuda/3d/algo3d.h
index f5fd207..b6b1db7 100644
--- a/include/astra/cuda/3d/algo3d.h
+++ b/include/astra/cuda/3d/algo3d.h
@@ -41,8 +41,6 @@ public:
 	bool setConeGeometry(const SDimensions3D& dims, const SConeProjection* projs, const SProjectorParams3D& params);
 	bool setPar3DGeometry(const SDimensions3D& dims, const SPar3DProjection* projs, const SProjectorParams3D& params);
 
-	void signalAbort() { shouldAbort = true; }
-
 protected:
 	void reset();
 
@@ -59,9 +57,6 @@ protected:
 	SPar3DProjection* par3DProjs;
 
 	float fOutputScale;
-
-	volatile bool shouldAbort;
-
 };
 
 
diff --git a/include/astra/cuda/3d/astra3d.h b/include/astra/cuda/3d/astra3d.h
index 28a8f01..a97efd6 100644
--- a/include/astra/cuda/3d/astra3d.h
+++ b/include/astra/cuda/3d/astra3d.h
@@ -157,10 +157,6 @@ public:
 	// It can be called after iterate().
 	float computeDiffNorm();
 
-	// Signal the algorithm that it should abort after the current iteration.
-	// This is intended to be called from another thread.
-	void signalAbort();
-
 protected:
 	AstraSIRT3d_internal *pData;
 };
@@ -274,10 +270,6 @@ public:
 	// It can be called after iterate().
 	float computeDiffNorm();
 
-	// Signal the algorithm that it should abort after the current iteration.
-	// This is intended to be called from another thread.
-	void signalAbort();
-
 protected:
 	AstraCGLS3d_internal *pData;
 };