fixed multi GPU API, added driver_api prefix to multi gpu samples

samples/gpu/multi.cpp

@@ -1,144 +0,0 @@
-/* This sample demonstrates the way you can perform independed tasks 
-   on the different GPUs */
-
-// Disable some warnings which are caused with CUDA headers
-#if defined(_MSC_VER)
-#pragma warning(disable: 4201 4408 4100)
-#endif
-
-#include <iostream>
-#include <cvconfig.h>
-#include <opencv2/core/core.hpp>
-#include <opencv2/gpu/gpu.hpp>
-
-#if !defined(HAVE_CUDA) || !defined(HAVE_TBB)
-
-int main()
-{
-#if !defined(HAVE_CUDA)
-    cout << "CUDA support is required (CMake key 'WITH_CUDA' must be true).\n";
-#endif
-
-#if !defined(HAVE_TBB)
-    cout << "TBB support is required (CMake key 'WITH_TBB' must be true).\n";
-#endif
-
-    return 0;
-}
-
-#else
-
-#include <cuda.h>
-#include <cuda_runtime.h>
-#include "opencv2/core/internal.hpp" // For TBB wrappers
-
-using namespace std;
-using namespace cv;
-using namespace cv::gpu;
-
-struct Worker { void operator()(int device_id) const; };
-void destroyContexts();
-
-#define safeCall(expr) safeCall_(expr, #expr, __FILE__, __LINE__)
-inline void safeCall_(int code, const char* expr, const char* file, int line)
-{
-    if (code != CUDA_SUCCESS)
-    {
-        cout << "CUDA driver API error: code " << code << ", expr " << expr
-            << ", file " << file << ", line " << line << endl;
-        destroyContexts();
-        exit(-1);
-    }
-}
-
-// Each GPU is associated with its own context
-CUcontext contexts[2];
-
-int main()
-{
-    int num_devices = getCudaEnabledDeviceCount();
-    if (num_devices < 2)
-    {
-        cout << "Two or more GPUs are required\n";
-        return -1;
-    }
-
-    for (int i = 0; i < num_devices; ++i)
-    {
-        DeviceInfo dev_info(i);
-        if (!dev_info.isCompatible())
-        {
-            cout << "GPU module isn't built for GPU #" << i << " ("
-                 << dev_info.name() << ", CC " << dev_info.majorVersion()
-                 << dev_info.minorVersion() << "\n";
-            return -1;
-        }
-    }
-
-    // Init CUDA Driver API
-    safeCall(cuInit(0));
-
-    // Create context for GPU #0
-    CUdevice device;
-    safeCall(cuDeviceGet(&device, 0));
-    safeCall(cuCtxCreate(&contexts[0], 0, device));
-
-    CUcontext prev_context;
-    safeCall(cuCtxPopCurrent(&prev_context));
-
-    // Create context for GPU #1
-    safeCall(cuDeviceGet(&device, 1));
-    safeCall(cuCtxCreate(&contexts[1], 0, device));
-
-    safeCall(cuCtxPopCurrent(&prev_context));
-
-    // Execute calculation in two threads using two GPUs
-    int devices[] = {0, 1};
-    parallel_do(devices, devices + 2, Worker());
-
-    destroyContexts();
-    return 0;
-}
-
-
-void Worker::operator()(int device_id) const
-{
-    // Set the proper context
-    safeCall(cuCtxPushCurrent(contexts[device_id]));
-
-    Mat src(1000, 1000, CV_32F);
-    Mat dst;
-
-    RNG rng(0);
-    rng.fill(src, RNG::UNIFORM, 0, 1);
-
-    // CPU works
-    transpose(src, dst);
-
-    // GPU works
-    GpuMat d_src(src);
-    GpuMat d_dst;
-    transpose(d_src, d_dst);
-
-    // Check results
-    bool passed = norm(dst - Mat(d_dst), NORM_INF) < 1e-3;
-    cout << "GPU #" << device_id << " (" << DeviceInfo().name() << "): "
-        << (passed ? "passed" : "FAILED") << endl;
-
-    // Deallocate data here, otherwise deallocation will be performed
-    // after context is extracted from the stack
-    d_src.release();
-    d_dst.release();
-
-    CUcontext prev_context;
-    safeCall(cuCtxPopCurrent(&prev_context));
-}
-
-
-void destroyContexts()
-{
-    safeCall(cuCtxDestroy(contexts[0]));
-    safeCall(cuCtxDestroy(contexts[1]));
-}
-
-#endif