Add single threaded version

.github/workflows/build_steps.sh

@@ -211,8 +211,26 @@ build_test_wasm() {
     source emsdk/emsdk_env.sh
     export PATH="$(pwd)/node_modules/.bin:$PATH"
 
-    emcmake cmake -B build_wasm -DCMAKE_INTERPROCEDURAL_OPTIMIZATION:BOOL=OFF $WASM_CMAKE_ARGS
-    cmake --build build_wasm
+    echo "Building Multi-Threaded version..."
+    emcmake cmake -B build_wasm_mt \
+        -DCMAKE_INTERPROCEDURAL_OPTIMIZATION:BOOL=OFF \
+        -DMUJOCO_WASM_THREADS=ON \
+        $WASM_CMAKE_ARGS
+    cmake --build build_wasm_mt --parallel $(nproc)
+
+    echo "Moving Multi-Thread version under mt subfolder..."
+    mkdir -p wasm/dist/mt
+    mv wasm/dist/mujoco.js wasm/dist/mt/
+    mv wasm/dist/mujoco.wasm wasm/dist/mt/
+    mv wasm/dist/mujoco.d.ts wasm/dist/mt/
+    mv wasm/dist/mujoco.wasm.map wasm/dist/mt/
+
+    echo "Building Single-Threaded version..."
+    emcmake cmake -B build_wasm_st \
+        -DCMAKE_INTERPROCEDURAL_OPTIMIZATION:BOOL=OFF \
+        -DMUJOCO_WASM_THREADS=OFF \
+        $WASM_CMAKE_ARGS
+    cmake --build build_wasm_st --parallel $(nproc)
 
     npm run test --prefix ./wasm
 }

wasm/CMakeLists.txt

@@ -31,11 +31,11 @@ if(NOT MUJOCO_WASM_FILES)
     message(FATAL_ERROR "No source files found in codegen/generated/")
 endif()
 
+option(MUJOCO_WASM_THREADS "Build with multi-threading support" ON)
+
 # Set Emscripten linker flags
 set(EMCC_LINKER_FLAGS
     "--bind"
-    "-pthread"
-    "-s PTHREAD_POOL_SIZE=navigator.hardwareConcurrency"
     "-s ASSERTIONS=1"
     "-s ALLOW_MEMORY_GROWTH=1"
     "-s EXPORT_ES6=1"
@@ -48,6 +48,13 @@ set(EMCC_LINKER_FLAGS
     "-g"
     "--emit-tsd mujoco.d.ts"
 )
+if(MUJOCO_WASM_THREADS)
+    list(APPEND EMCC_LINKER_FLAGS
+        "-pthread"
+        "-s PTHREAD_POOL_SIZE=navigator.hardwareConcurrency"
+    )
+    add_definitions(-DMUJOCO_WASM_THREADS)
+endif()
 string (REPLACE ";" " " EMCC_LINKER_FLAGS_STR "${EMCC_LINKER_FLAGS}")
 
 add_executable(mujoco_wasm ${MUJOCO_WASM_FILES})

wasm/package.npm.json

@@ -24,13 +24,31 @@
     "javascript",
     "typescript"
   ],
-  "main": "mujoco.js",
-  "types": "mujoco.d.ts",
+  "exports": {
+    ".": {
+      "types": "./mujoco.d.ts",
+      "import": "./mujoco.js",
+      "default": "./mujoco.js"
+    },
+    "./mt": {
+      "types": "./mt/mujoco.d.ts",
+      "import": "./mt/mujoco.js",
+      "default": "./mt/mujoco.js"
+    },
+    "./mujoco.wasm": "./mujoco.wasm",
+    "./mujoco.wasm.map": "./mujoco.wasm.map",
+    "./mt/mujoco.wasm": "./mt/mujoco.wasm",
+    "./mt/mujoco.wasm.map": "./mt/mujoco.wasm.map"
+  },
   "files": [
     "mujoco.js",
     "mujoco.d.ts",
     "mujoco.wasm",
     "mujoco.wasm.map",
+    "mt/mujoco.js",
+    "mt/mujoco.d.ts",
+    "mt/mujoco.wasm",
+    "mt/mujoco.wasm.map",
     "README.md"
   ],
   "author": "Google DeepMind",