use async context waitForContext()

Author: MichealReed

cmake/example.cmake

@@ -45,14 +45,16 @@ if(EMSCRIPTEN)
     # Set Emscripten-specific link flags that enable WASM output and expose certain symbols.
     # Needed to use updated version, emdawnwebgpu
     set_target_properties(${PROJECT_NAME} PROPERTIES LINK_FLAGS "\
+        -O3 \
         -sUSE_WEBGPU=0 \
         -sWASM=1 \
         -DDAWN_EMSCRIPTEN_TOOLCHAIN=${EMSCRIPTEN_DIR} \
         -sEXPORTED_FUNCTIONS=_main,_malloc,_free,_memcpy \
         -sEXPORTED_RUNTIME_METHODS=ccall \
         -sUSE_GLFW=3 \
-        -sALLOW_MEMORY_GROWTH=1 -sSTACK_SIZE=5MB \
+        -sALLOW_MEMORY_GROWTH=1 -sSTACK_SIZE=15MB \
         -sASYNCIFY \
+        -sASYNCIFY_DEBUG \
         --js-library=${DAWN_BUILD_DIR}/gen/src/emdawnwebgpu/library_webgpu_enum_tables.js \
         --js-library=${DAWN_BUILD_DIR}/gen/src/emdawnwebgpu/library_webgpu_generated_struct_info.js \
         --js-library=${DAWN_BUILD_DIR}/gen/src/emdawnwebgpu/library_webgpu_generated_sig_info.js \

examples/hello_world/run.cpp

@@ -28,16 +28,14 @@ int main(int argc, char **argv) {
   printf("--------------\n\n");
 
   // std::unique_ptr<Context> ctx = createContext();
-  Context ctx = createContext();
+  Context ctx = waitForContext();
   static constexpr size_t N = 10000;
   std::array<float, N> inputArr, outputArr;
   for (int i = 0; i < N; ++i) {
     inputArr[i] = static_cast<float>(i) / 10.0; // dummy input data
   }
   Tensor input = createTensor(ctx, Shape{N}, kf32, inputArr.data());
   Tensor output = createTensor(ctx, Shape{N}, kf32);
-  std::promise<void> promise;
-  std::future<void> future = promise.get_future();
   std::future<Kernel> kernelFuture = createKernel(ctx, {kGelu, 256, kf32},
                            Bindings{input, output},
                            {cdiv(N, 256), 1, 1});