reverted wrong commit for one of gpu samples

samples/gpu/driver_api_stereo_multi.cpp

@@ -32,11 +32,7 @@ int main()
 
 #include <cuda.h>
 #include <cuda_runtime.h>
-#include <GL/gl.h>
-#include <cudaGL.h>
 #include "opencv2/core/internal.hpp" // For TBB wrappers
-#include "tbb/tbb.h"
-#include "tbb/mutex.h"
 
 using namespace std;
 using namespace cv;
@@ -58,14 +54,14 @@ inline void safeCall_(int code, const char* expr, const char* file, int line)
 }
 
 // Each GPU is associated with its own context
-CUcontext contexts[/*2*/1];
+CUcontext contexts[2];
 
-void inline contextOn(int id) 
+void inline contextOn(int id)
 {
     safeCall(cuCtxPushCurrent(contexts[id]));
 }
 
-void inline contextOff() 
+void inline contextOff()
 {
     CUcontext prev_context;
     safeCall(cuCtxPopCurrent(&prev_context));
@@ -80,10 +76,6 @@ GpuMat d_result[2];
 // CPU result
 Mat result;
 
-int some[2];
-
-tbb::mutex mutex;
-
 int main(int argc, char** argv)
 {
     if (argc < 3)
@@ -93,11 +85,11 @@ int main(int argc, char** argv)
     }
 
     int num_devices = getCudaEnabledDeviceCount();
-//    if (num_devices < 2)
-//    {
-//        std::cout << "Two or more GPUs are required\n";
-//        return -1;
-//    }
+    if (num_devices < 2)
+    {
+        std::cout << "Two or more GPUs are required\n";
+        return -1;
+    }
 
     for (int i = 0; i < num_devices; ++i)
     {
@@ -131,14 +123,13 @@ int main(int argc, char** argv)
     // Create context for GPU #0
     CUdevice device;
     safeCall(cuDeviceGet(&device, 0));
-    safeCall(cuGLCtxCreate(&contexts[0], 0, device));
-    //safeCall(cuCtxCreate(&contexts[0], 0, device));
+    safeCall(cuCtxCreate(&contexts[0], 0, device));
     contextOff();
 
-//    // Create context for GPU #1
-//    safeCall(cuDeviceGet(&device, 0));
-//    safeCall(cuCtxCreate(&contexts[1], 0, device));
-//    contextOff();
+    // Create context for GPU #1
+    safeCall(cuDeviceGet(&device, 1));
+    safeCall(cuCtxCreate(&contexts[1], 0, device));
+    contextOff();
 
     // Split source images for processing on GPU #0
     contextOn(0);
@@ -148,20 +139,15 @@ int main(int argc, char** argv)
     contextOff();
 
     // Split source images for processing on the GPU #1
-    contextOn(0);
+    contextOn(1);
     d_left[1].upload(left.rowRange(left.rows / 2, left.rows));
     d_right[1].upload(right.rowRange(right.rows / 2, right.rows));
     bm[1] = new StereoBM_GPU();
     contextOff();
 
-    some[0] = some[1] = 0;
     // Execute calculation in two threads using two GPUs
-    vector<int> devices;
-    for (int i = 0; i < 4; ++i)
-        devices.push_back(rand()%2);
-    tbb::parallel_do(&devices[0], &devices[devices.size() - 1], Worker());
-
-    cout << some[0] << " " << some[1] << endl;
+    int devices[] = {0, 1};
+    parallel_do(devices, devices + 2, Worker());
 
     // Release the first GPU resources
     contextOn(0);
@@ -173,7 +159,7 @@ int main(int argc, char** argv)
     contextOff();
 
     // Release the second GPU resources
-    contextOn(0);
+    contextOn(1);
     imshow("GPU #1 result", Mat(d_result[1]));
     d_left[1].release();
     d_right[1].release();
@@ -189,9 +175,7 @@ int main(int argc, char** argv)
 
 void Worker::operator()(int device_id) const
 {
-    mutex.lock();
-
-    contextOn(0);
+    contextOn(device_id);
 
     bm[device_id]->operator()(d_left[device_id], d_right[device_id],
                               d_result[device_id]);
@@ -200,16 +184,13 @@ void Worker::operator()(int device_id) const
         << "): finished\n";
 
     contextOff();
-
-    mutex.unlock();
 }
 
 
 void destroyContexts()
 {
     safeCall(cuCtxDestroy(contexts[0]));
-    //safeCall(cuCtxDestroy(contexts[1]));
+    safeCall(cuCtxDestroy(contexts[1]));
 }
 
 #endif
-