add cv::gpu::StreamAccessor::wrapStream method

it allows to import existed CUDA stream to OpenCV

modules/gpu/test/test_stream.cpp

@@ -44,6 +44,8 @@
 
 #ifdef HAVE_CUDA
 
+#include "opencv2/gpu/stream_accessor.hpp"
+
 using namespace cvtest;
 
 #if CUDART_VERSION >= 5000
@@ -125,6 +127,25 @@ GPU_TEST_P(Async, Convert)
     stream.waitForCompletion();
 }
 
+GPU_TEST_P(Async, WrapStream)
+{
+    cudaStream_t cuda_stream = NULL;
+    ASSERT_EQ(cudaSuccess, cudaStreamCreate(&cuda_stream));
+
+    cv::gpu::Stream stream = cv::gpu::StreamAccessor::wrapStream(cuda_stream);
+
+    stream.enqueueUpload(src, d_src);
+    stream.enqueueConvert(d_src, d_dst, CV_32S);
+    stream.enqueueDownload(d_dst, dst);
+
+    Async* test = this;
+    stream.enqueueHostCallback(checkConvert, test);
+
+    stream.waitForCompletion();
+
+    ASSERT_EQ(cudaSuccess, cudaStreamDestroy(cuda_stream));
+}
+
 INSTANTIATE_TEST_CASE_P(GPU_Stream, Async, ALL_DEVICES);
 
 #endif