minor changes in multi_gpu sample

diff --git a/samples/gpu/multi.cpp b/samples/gpu/multi.cpp
new file mode 100644 (file)
index 0000000..9063c97
--- /dev/null
+++ b/samples/gpu/multi.cpp
@@ -0,0 +1,122 @@
+// Disable some warnings which are caused with CUDA headers\r
+#pragma warning(disable: 4201 4408 4100)\r
+\r
+#include <iostream>\r
+#include <cvconfig.h>\r
+#include <opencv2/core/core.hpp>\r
+#include <opencv2/gpu/gpu.hpp>\r
+\r
+#if !defined(HAVE_CUDA) || !defined(HAVE_TBB)\r
+\r
+int main()\r
+{\r
+#if !defined(HAVE_CUDA)\r
+    cout << "CUDA support is required (CMake key 'WITH_CUDA' must be true).\n";\r
+#endif\r
+\r
+#if !defined(HAVE_TBB)\r
+    cout << "TBB support is required (CMake key 'WITH_TBB' must be true).\n";\r
+#endif\r
+\r
+    return 0;\r
+}\r
+\r
+#else\r
+\r
+#include <cuda.h>\r
+#include <cuda_runtime.h>\r
+#include "opencv2/core/internal.hpp" // For TBB wrappers\r
+\r
+using namespace std;\r
+using namespace cv;\r
+using namespace cv::gpu;\r
+\r
+struct Worker { void operator()(int device_id) const; };\r
+void destroyContexts();\r
+\r
+#define cuSafeCall(code) if (code != CUDA_SUCCESS) { \\r
+    cout << "CUDA driver API error: code " << code \\r
+        << ", file " << __FILE__ << ", line " << __LINE__ << endl; \\r
+    destroyContexts(); \\r
+    exit(-1); \\r
+}\r
+\r
+\r
+// Each GPU is associated with its own context\r
+CUcontext contexts[2];\r
+\r
+\r
+int main()\r
+{\r
+    if (getCudaEnabledDeviceCount() < 2)\r
+    {\r
+        cout << "Two or more GPUs are required\n";\r
+        return -1;\r
+    }\r
+\r
+    cuSafeCall(cuInit(0));\r
+\r
+    // Create context for the first GPU\r
+    CUdevice device;\r
+    cuSafeCall(cuDeviceGet(&device, 0));\r
+    cuSafeCall(cuCtxCreate(&contexts[0], 0, device));\r
+\r
+    CUcontext prev_context;\r
+    cuSafeCall(cuCtxPopCurrent(&prev_context));\r
+\r
+    // Create context for the second GPU\r
+    cuSafeCall(cuDeviceGet(&device, 1));\r
+    cuSafeCall(cuCtxCreate(&contexts[1], 0, device));\r
+\r
+    cuSafeCall(cuCtxPopCurrent(&prev_context));\r
+\r
+    // Execute calculation in two threads using two GPUs\r
+    int devices[] = {0, 1};\r
+    parallel_do(devices, devices + 2, Worker());\r
+\r
+    destroyContexts();\r
+    return 0;\r
+}\r
+\r
+\r
+void Worker::operator()(int device_id) const\r
+{\r
+    // Set proper context\r
+    cuSafeCall(cuCtxPushCurrent(contexts[device_id]));\r
+\r
+    Mat src(1000, 1000, CV_32F);\r
+    Mat dst;\r
+\r
+    RNG rng(0);\r
+    rng.fill(src, RNG::UNIFORM, 0, 1);\r
+\r
+    // CPU works\r
+    transpose(src, dst);\r
+\r
+    GpuMat d_src(src);\r
+    GpuMat d_dst;\r
+\r
+    // GPU works\r
+    transpose(d_src, d_dst);\r
+\r
+    // Check results\r
+    bool passed = norm(dst - Mat(d_dst), NORM_INF) < 1e-3;\r
+    cout << "GPU #" << device_id << ": "<< (passed ? "passed" : "FAILED") << endl;\r
+\r
+    // Deallocate data here, otherwise deallocation will be performed\r
+    // after context is extracted from the stack\r
+    d_src.release();\r
+    d_dst.release();\r
+\r
+    CUcontext prev_context;\r
+    cuSafeCall(cuCtxPopCurrent(&prev_context));\r
+}\r
+\r
+\r
+void destroyContexts()\r
+{\r
+    cuSafeCall(cuCtxDestroy(contexts[0]));\r
+    cuSafeCall(cuCtxDestroy(contexts[1]));\r
+}\r
+\r
+#endif
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