Add read_arrays definition for CUDA

src/CUDAStream.cu

@@ -39,7 +39,16 @@ void CUDAStream<T>::write_arrays(const std::vector<T>& a, const std::vector<T>&
 template <class T>
 void CUDAStream<T>::read_arrays(std::vector<T>& a, std::vector<T>& b, std::vector<T>& c)
 {
+  // Copy device memory to host
+  cudaMemcpy(a.data(), d_a, a.size()*sizeof(T), cudaMemcpyDeviceToHost);
+  check_error();
+  cudaMemcpy(b.data(), d_b, b.size()*sizeof(T), cudaMemcpyDeviceToHost);
+  check_error();
+  cudaMemcpy(c.data(), d_c, c.size()*sizeof(T), cudaMemcpyDeviceToHost);
+  check_error();
 }
+
+
 template <typename T>
 __global__ void copy_kernel(const T * a, T * c)
 {

src/main.cpp

@@ -33,6 +33,9 @@ int main(int argc, char *argv[])
 
   stream->copy();
 
+  stream->read_arrays(a, b, c);
+  std::cout << c[105] << std::endl;
+
   delete[] stream;
 
 }