added a wrapper class for UniformGPUScheme class.

src/gpu/communication/UniformGPUScheme.h

@@ -73,6 +73,52 @@ namespace communication {
  * When running multiple \ref UniformGPUScheme concurrently, different MPI tags
  * have to be used for the schemes: the tag can be passed in the constructor.
  */
+template<typename Stencil>
+class GPUStreamRAII {
+ public:
+   GPUStreamRAII() {
+      for (uint_t i = 0; i < Stencil::Q; ++i)
+         WALBERLA_GPU_CHECK(gpuStreamCreate(&streams_[i]))
+
+   }
+
+   ~GPUStreamRAII() {
+      for (uint_t i = 0; i < Stencil::Q; ++i) {
+         WALBERLA_GPU_CHECK(gpuStreamDestroy(streams_[i]));
+      }
+   }
+
+   // Delete copy constructor and copy assignment
+   GPUStreamRAII(const GPUStreamRAII&) = delete;
+   GPUStreamRAII& operator=(const GPUStreamRAII&) = delete;
+
+   GPUStreamRAII(GPUStreamRAII&& other) noexcept {
+      for (uint_t i = 0; i < Stencil::Q; ++i) {
+         streams_[i] = other.streams_[i];
+         other.streams_[i] = nullptr;
+      }
+   }
+
+   GPUStreamRAII& operator=(GPUStreamRAII&& other) noexcept {
+      if (this != &other) {
+         for (uint_t i = 0; i < Stencil::Q; ++i) {
+            if (streams_[i]) {
+               WALBERLA_GPU_CHECK(gpuStreamDestroy(streams_[i]));
+            }
+            streams_[i] = other.streams_[i];
+            other.streams_[i] = nullptr;
+         }
+      }
+      return *this;
+   }
+
+   //gpuStream_t get(uint_t index) const { return streams_[index]; }
+
+
+ private:
+   std::array<gpuStream_t, Stencil::Q> streams_;
+};
+
    template<typename Stencil>
    class UniformGPUScheme
    {
@@ -88,11 +134,12 @@ namespace communication {
                                   const bool sendDirectlyFromGPU = false,
                                   const bool useLocalCommunication = true,
                                   const int tag = 5432 );
-       ~UniformGPUScheme()
+       /*~UniformGPUScheme()
        {
           for (uint_t i = 0; i < Stencil::Q; ++i)
-             WALBERLA_GPU_CHECK(gpuStreamDestroy(streams_[i]))
-       }
+             WALBERLA_GPU_CHECK(gpuStreamDestroy(ravi_[i]))
+       }*/
+       ~UniformGPUScheme() = default;
 
        void addPackInfo( const shared_ptr<GeneratedGPUPackInfo> &pi );
 
@@ -135,10 +182,15 @@ namespace communication {
        Set<SUID> requiredBlockSelectors_;
        Set<SUID> incompatibleBlockSelectors_;
 
-       std::array<gpuStream_t, Stencil::Q> streams_;
+       //std::array<gpuStream_t, Stencil::Q> streams_; // array of RAII wrappers
+       std::array<GPUStreamRAII<Stencil>, Stencil::Q> streams_;
+
    };
 
 
+
+
+
 } // namespace communication
 } // namespace gpu
 } // namespace walberla