implement callASync

src/Proxy.h

@@ -456,6 +456,82 @@ void callSync(void (T::*memberFunc)(Args1...), Args2&&... args) {
        Exception(ValueError, "callSync(): Unknown resource type");
    }
 }
+template <typename RetType, typename... Args1, typename... Args2>
+std::future<RetType> callAsync(RetType (T::*memberFunc)(Args1...), Args2&&... args) {
+   switch (location.type) {
+   case Resource::CPU:
+       if (location.is_local()) {
+           return std::async(std::launch::async, [this, memberFunc, args...] {
+               return (addr->*memberFunc)(args...);
+           });
+       } else {
+           #ifdef USE_MPI
+           return std::async(std::launch::async, [this, memberFunc, args...] {
+               RetType result;
+               MPI_Send(args..., location.id, MPI_COMM_WORLD);
+               MPI_Recv(&result, sizeof(RetType), MPI_BYTE, location.id, MPI_ANY_TAG, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
+               return result;
+           });
+           #else
+           Exception(NotImplementedError, "Non-local CPU calls require MPI support");
+           #endif
+       }
+       break;
+   case Resource::GPU:
+       if (location.is_local()) {
+           return std::async(std::launch::async, [this, memberFunc, args...] {
+               RetType* dest;
+               RetType result;
+               gpuErrchk(cudaMalloc(&dest, sizeof(RetType)));
+               proxy_sync_call_kernel<T, RetType, Args2...><<<1,32>>>(dest, addr, memberFunc, args...);
+               gpuErrchk(cudaMemcpy(&result, dest, sizeof(RetType), cudaMemcpyDeviceToHost));
+               gpuErrchk(cudaFree(dest));
+               return result;
+           });
+       } else {
+           return std::async(std::launch::async, [this, memberFunc, args...] {
+               int current_device;
+               gpuErrchk(cudaGetDevice(&current_device));
+               gpuErrchk(cudaSetDevice(location.id));
+               
+               RetType* dest;
+               RetType result;
+               gpuErrchk(cudaMalloc(&dest, sizeof(RetType)));
+               proxy_sync_call_kernel<T, RetType, Args2...><<<1,32>>>(dest, addr, memberFunc, args...);
+               gpuErrchk(cudaMemcpy(&result, dest, sizeof(RetType), cudaMemcpyDeviceToHost));
+               gpuErrchk(cudaFree(dest));
+               
+               gpuErrchk(cudaSetDevice(current_device));
+               return result;
+           });
+       }
+       break;
+   case Resource::MPI:
+       #ifdef USE_MPI
+           return std::async(std::launch::async, [this, memberFunc, args...] {
+               int rank, size;
+               MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+               MPI_Comm_size(MPI_COMM_WORLD, &size);
+
+               if (rank == location.id) {
+                   RetType result = (addr->*memberFunc)(args...);
+                   MPI_Bcast(&result, sizeof(RetType), MPI_BYTE, location.id, MPI_COMM_WORLD);
+                   return result;
+               } else {
+                   RetType result;
+                   MPI_Bcast(&result, sizeof(RetType), MPI_BYTE, location.id, MPI_COMM_WORLD);
+                   return result;
+               }
+           });
+       #else
+           Exception(NotImplementedError, "Async MPI calls require USE_MPI flag");
+       #endif
+       break;
+   default:
+       Exception(ValueError, "callAsync(): Unknown resource type");
+   }
+   return std::async(std::launch::async, [] { return RetType{}; });
+}
 
 // Specialization for bool/int/float types that do not have member functions
 template<typename T>