added enqueueHostCallback method to gpu::Stream

modules/gpu/include/opencv2/gpu/gpu.hpp

@@ -145,43 +145,49 @@ public:
     ~Stream();
 
     Stream(const Stream&);
-    Stream& operator=(const Stream&);
+    Stream& operator =(const Stream&);
 
     bool queryIfComplete();
     void waitForCompletion();
 
-    //! downloads asynchronously.
+    //! downloads asynchronously
     // Warning! cv::Mat must point to page locked memory (i.e. to CudaMem data or to its subMat)
     void enqueueDownload(const GpuMat& src, CudaMem& dst);
     void enqueueDownload(const GpuMat& src, Mat& dst);
 
-    //! uploads asynchronously.
+    //! uploads asynchronously
     // Warning! cv::Mat must point to page locked memory (i.e. to CudaMem data or to its ROI)
     void enqueueUpload(const CudaMem& src, GpuMat& dst);
     void enqueueUpload(const Mat& src, GpuMat& dst);
 
+    //! copy asynchronously
     void enqueueCopy(const GpuMat& src, GpuMat& dst);
 
+    //! memory set asynchronously
     void enqueueMemSet(GpuMat& src, Scalar val);
     void enqueueMemSet(GpuMat& src, Scalar val, const GpuMat& mask);
 
-    // converts matrix type, ex from float to uchar depending on type
-    void enqueueConvert(const GpuMat& src, GpuMat& dst, int type, double a = 1, double b = 0);
+    //! converts matrix type, ex from float to uchar depending on type
+    void enqueueConvert(const GpuMat& src, GpuMat& dst, int dtype, double a = 1, double b = 0);
+
+    //! adds a callback to be called on the host after all currently enqueued items in the stream have completed
+    typedef void (*StreamCallback)(Stream& stream, int status, void* userData);
+    void enqueueHostCallback(StreamCallback callback, void* userData);
 
     static Stream& Null();
 
     operator bool() const;
 
 private:
+    struct Impl;
+
+    explicit Stream(Impl* impl);
     void create();
     void release();
 
-    struct Impl;
     Impl *impl;
 
     friend struct StreamAccessor;
-
-    explicit Stream(Impl* impl);
 };