Added option to compile the library with multithreading enabled (#111)

* Added ENABLE_MULTI_THREADING option * Added BUILD_WASM_COMPAT_ONLY option to only build the WASM compat version for faster compiling * Added module that can serve the examples with the correct COEP/COOP for multithreading See discussion at #110
jrouwe · Feb 23, 2024 · 893be84 · 893be84
1 parent 26ac07e
commit 893be84
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diff --git a/.gitignore b/.gitignore
@@ -2,3 +2,4 @@ Build/
 dist/
 node_modules
 Examples/js/jolt-physics.wasm-compat.js
+Examples/js/jolt-physics.wasm-compat.worker.js
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -14,6 +14,15 @@ set(OUTPUT_FOLDER ${CMAKE_CURRENT_SOURCE_DIR}/dist/)
 # Option to turn on memory profiling
 option(ENABLE_MEMORY_PROFILER "Enable emscriptens memory profiler to help find leaks" OFF)
 
+# Option to turn on double precision
+option(DOUBLE_PRECISION "Compile the library in double precision mode" OFF)
+
+# Option to turn multi threading on
+option(ENABLE_MULTI_THREADING "Compile the library in multi threading mode (warning: doesn't work in Safari nor with any JS callbacks currently)'" OFF)
+
+# Option to speed up compilation by only compiling the WASM compat version
+option(BUILD_WASM_COMPAT_ONLY "Compile online the WASM compat version of the library (speeds up compilation)" OFF)
+
 # The configurations we support
 set(CMAKE_CONFIGURATION_TYPES "Debug;Release;Distribution")
 
@@ -29,6 +38,20 @@ set(GENERATE_DEBUG_SYMBOLS ON)
 # Use 32-bit object layers to support more bits in ObjectLayerPairFilterMask
 set(OBJECT_LAYER_BITS 32)
 
+# Enable multi threading
+if (ENABLE_MULTI_THREADING)
+	set(MULTI_THREADED_FLAG 
+		-pthread 
+		-s SHARED_MEMORY)
+	set(ENVIRONMENT_FLAG
+		-s ENVIRONMENT='web,node,worker' 
+		-s PTHREAD_POOL_SIZE=16)
+	set(CMAKE_CXX_FLAGS "-pthread -s SHARED_MEMORY")
+else()
+	set(MULTI_THREADED_FLAG "")
+	set(ENVIRONMENT_FLAG "-s ENVIRONMENT='web,node'")
+endif()
+
 # Include Jolt
 include(FetchContent)
 FetchContent_Declare(
@@ -59,9 +82,10 @@ set(EMCC_ARGS
   --extern-pre-js ${JOLT_FRONT_MATTER_FILE}
   --post-js glue.js
   --closure=1
+  ${MULTI_THREADED_FLAG}
   -s ALLOW_MEMORY_GROWTH=${ALLOW_MEMORY_GROWTH}
   -s ALLOW_TABLE_GROWTH=1
-  -s ENVIRONMENT='web,node'
+  ${ENVIRONMENT_FLAG}
   -s EXPORT_ES6=1
   -s EXPORT_NAME="Jolt"
   -s MODULARIZE=1
@@ -102,6 +126,7 @@ set(EMCC_GLUE_ARGS
   -I${JoltPhysics_SOURCE_DIR}/..
   -Wall
   -std=c++17
+  ${MULTI_THREADED_FLAG}
   -DJPH_OBJECT_LAYER_BITS=32
   -include ${JOLT_HEADER_FILE}
   ${MEMORY_PROFILER_FLAG})
@@ -128,48 +153,48 @@ if (DOUBLE_PRECISION)
 	set(EMCC_GLUE_ARGS ${EMCC_GLUE_ARGS} -DJPH_DOUBLE_PRECISION)
 endif()
 
-#######################################
 project("JoltPhysics.js")
 
-#######################################
 add_custom_command(
-  OUTPUT glue.cpp glue.js
-  BYPRODUCTS parser.out WebIDLGrammar.pkl
-  COMMAND ${PYTHON} ${WEBIDL_BINDER_SCRIPT} ${JOLT_IDL_FILE} glue
-  DEPENDS ${JOLT_IDL_FILE}
-  COMMENT "Generating JoltPhysics.js bindings"
-  VERBATIM)
+	OUTPUT glue.cpp glue.js
+	BYPRODUCTS parser.out WebIDLGrammar.pkl
+	COMMAND ${PYTHON} ${WEBIDL_BINDER_SCRIPT} ${JOLT_IDL_FILE} glue
+	DEPENDS ${JOLT_IDL_FILE}
+	COMMENT "Generating JoltPhysics.js bindings"
+	VERBATIM)
+
 add_custom_command(
-  OUTPUT glue.o
-  COMMAND emcc glue.cpp ${EMCC_GLUE_ARGS} -o glue.o
-  DEPENDS glue.cpp ${JOLT_HEADER_FILE}
-  COMMENT "Building JoltPhysics.js bindings"
-  VERBATIM)
+	OUTPUT glue.o
+	COMMAND emcc glue.cpp ${EMCC_GLUE_ARGS} -o glue.o
+	DEPENDS glue.cpp ${JOLT_HEADER_FILE}
+	COMMENT "Building JoltPhysics.js bindings"
+	VERBATIM)
 add_custom_target(jolt-bindings ALL DEPENDS glue.js glue.o)
 
-#######################################
-add_custom_command(
-  OUTPUT ${OUTPUT_FOLDER}jolt-physics.js
-  COMMAND emcc glue.o $<TARGET_FILE:Jolt> ${EMCC_JS_ARGS} -o ${OUTPUT_FOLDER}jolt-physics.js
-  DEPENDS jolt-bindings ${JOLT_FRONT_MATTER_FILE} ${JOLT_TARGETS} ${JOLT_IDL_FILE} ${JOLT_HEADER_FILE}
-  COMMENT "Building JoltPhysics.js javascript"
-  VERBATIM)
-add_custom_target(jolt-javascript ALL DEPENDS ${OUTPUT_FOLDER}jolt-physics.js)
-
-#######################################
-add_custom_command(
-  OUTPUT ${OUTPUT_FOLDER}jolt-physics.wasm.js ${OUTPUT_FOLDER}jolt-physics.wasm.wasm
-  COMMAND emcc glue.o $<TARGET_FILE:Jolt> ${EMCC_WASM_ARGS} -o ${OUTPUT_FOLDER}jolt-physics.wasm.js
-  DEPENDS jolt-bindings ${JOLT_FRONT_MATTER_FILE} ${JOLT_TARGETS} ${JOLT_IDL_FILE} ${JOLT_HEADER_FILE}
-  COMMENT "Building JoltPhysics.js webassembly"
-  VERBATIM)
-add_custom_target(jolt-wasm ALL DEPENDS ${OUTPUT_FOLDER}jolt-physics.wasm.js ${OUTPUT_FOLDER}jolt-physics.wasm.wasm)
-
-#######################################
+if (NOT BUILD_WASM_COMPAT_ONLY)
+	if (NOT ENABLE_MULTI_THREADING) # Not compatible with multi threading due to error: 'void wasm::I64ToI32Lowering::visitStore(Store *): Assertion `!curr->isAtomic && "atomic store not implemented"' failed.'
+		add_custom_command(
+			OUTPUT ${OUTPUT_FOLDER}jolt-physics.js
+			COMMAND emcc glue.o $<TARGET_FILE:Jolt> ${EMCC_JS_ARGS} -o ${OUTPUT_FOLDER}jolt-physics.js
+			DEPENDS jolt-bindings ${JOLT_FRONT_MATTER_FILE} ${JOLT_TARGETS} ${JOLT_IDL_FILE} ${JOLT_HEADER_FILE}
+			COMMENT "Building JoltPhysics.js javascript"
+			VERBATIM)
+		add_custom_target(jolt-javascript ALL DEPENDS ${OUTPUT_FOLDER}jolt-physics.js)
+	endif()
+
+	add_custom_command(
+		OUTPUT ${OUTPUT_FOLDER}jolt-physics.wasm.js ${OUTPUT_FOLDER}jolt-physics.wasm.wasm
+		COMMAND emcc glue.o $<TARGET_FILE:Jolt> ${EMCC_WASM_ARGS} -o ${OUTPUT_FOLDER}jolt-physics.wasm.js
+		DEPENDS jolt-bindings ${JOLT_FRONT_MATTER_FILE} ${JOLT_TARGETS} ${JOLT_IDL_FILE} ${JOLT_HEADER_FILE}
+		COMMENT "Building JoltPhysics.js webassembly"
+		VERBATIM)
+	add_custom_target(jolt-wasm ALL DEPENDS ${OUTPUT_FOLDER}jolt-physics.wasm.js ${OUTPUT_FOLDER}jolt-physics.wasm.wasm)
+endif()
+
 add_custom_command(
-  OUTPUT ${OUTPUT_FOLDER}jolt-physics.wasm-compat.js
-  COMMAND emcc glue.o $<TARGET_FILE:Jolt> ${EMCC_WASM_COMPAT_ARGS} -o ${OUTPUT_FOLDER}jolt-physics.wasm-compat.js
-  DEPENDS jolt-bindings ${JOLT_FRONT_MATTER_FILE} ${JOLT_TARGETS} ${JOLT_IDL_FILE} ${JOLT_HEADER_FILE}
-  COMMENT "Building JoltPhysics.js compat webassembly"
-  VERBATIM)
+	OUTPUT ${OUTPUT_FOLDER}jolt-physics.wasm-compat.js
+	COMMAND emcc glue.o $<TARGET_FILE:Jolt> ${EMCC_WASM_COMPAT_ARGS} -o ${OUTPUT_FOLDER}jolt-physics.wasm-compat.js
+	DEPENDS jolt-bindings ${JOLT_FRONT_MATTER_FILE} ${JOLT_TARGETS} ${JOLT_IDL_FILE} ${JOLT_HEADER_FILE}
+	COMMENT "Building JoltPhysics.js compat webassembly"
+	VERBATIM)
 add_custom_target(jolt-wasm-compat ALL DEPENDS ${OUTPUT_FOLDER}jolt-physics.wasm-compat.js)
diff --git a/JoltJS.h b/JoltJS.h
@@ -424,7 +424,7 @@ class JoltInterface
 
 private:
 	TempAllocatorImpl *		mTempAllocator;
-	JobSystemThreadPool		mJobSystem { cMaxPhysicsJobs, cMaxPhysicsBarriers, (int)thread::hardware_concurrency() - 1 };
+	JobSystemThreadPool		mJobSystem { cMaxPhysicsJobs, cMaxPhysicsBarriers, min<int>(thread::hardware_concurrency() - 1, 16) }; // Limit to 16 threads since we limit the webworker thread pool size to this as well
 	BroadPhaseLayerInterface *mBroadPhaseLayerInterface = nullptr;
 	ObjectVsBroadPhaseLayerFilter *mObjectVsBroadPhaseLayerFilter = nullptr;
 	ObjectLayerPairFilter *	mObjectLayerPairFilter = nullptr;

diff --git a/README.md b/README.md
@@ -85,13 +85,25 @@ This project has only been compiled under Linux.
 
 * Install [emscripten](https://emscripten.org/) and ensure that its environment variables have been setup
 * Install [cmake](https://cmake.org/)
-* Run ```./build.sh``` for the optimized build, ```./build.sh Debug``` for the debug build or ```./build.sh Debug -DENABLE_MEMORY_PROFILER=ON``` for the debug build with memory tracking
+* Run ```./build.sh Distribution``` for the optimized build, ```./build.sh Debug``` for the debug build.
 
-You can also compile the project in double precision mode using ```./build.sh Distribution -DDOUBLE_PRECISION=ON```, currently no package is provided for this.
+Additional options that can be provided to ```build.sh```:
+
+* ```-DENABLE_MEMORY_PROFILER=ON``` will enable memory tracking to detect leaks.
+* ```-DDOUBLE_PRECISION=ON``` will enable the double precision mode. This allows worlds larger than a couple of km.
+* ```-DENABLE_MULTI_THREADING=ON``` will enable multi threading. Note that due to a bug in Safari this currently doesn't work in that brower. It is also incompatible with any JavaScript callback function that are triggered from web workers. See [this](https://github.com/jrouwe/JoltPhysics.js/discussions/110) ticket.
+* ```-DBUILD_WASM_COMPAT_ONLY=ON``` speeds up the build by only compiling the WASM compat version which the examples use.
 
 ## Running
 
-By default the examples use the WASM version of Jolt. This requires serving the html file using a web server rather than opening the html file directly. Use e.g. [serve](https://www.npmjs.com/package/serve) to quickly host the file.
+By default the examples use the WASM version of Jolt. This requires serving the html file using a web server rather than opening the html file directly.
+
+Go to the serveexamples folder and run
+
+```
+npm install
+node serveexamples
+```
 
 If you need to debug the C++ code take a look at [WASM debugging](https://developer.chrome.com/blog/wasm-debugging-2020/).
 
@@ -120,10 +132,6 @@ The Body class is also a special case, it is destroyed through BodyInterface.Des
 
 Almost everything else can be destroyed straight after it has been passed to Jolt. [An example that shows how to properly clean up using Jolt is here](https://github.com/jrouwe/JoltPhysics.js/blob/main/Examples/proper_cleanup.html).
 
-## Credits
-
-This project was started from the [Ammo.js](https://github.com/kripken/ammo.js) code, but little remains of it as the Jolt Physics API is very different from the Bullet API.
-
 ## License
 
 The project is distributed under the [MIT license](LICENSE).
diff --git a/build.sh b/build.sh
@@ -54,7 +54,7 @@ if [ $? -ne 0 ]; then
 	exit 1
 fi
 
-cp ./dist/jolt-physics.wasm-compat.js ./Examples/js/jolt-physics.wasm-compat.js
+cp ./dist/jolt-physics.wasm-compat*.js ./Examples/js/
 if [ $? -ne 0 ]; then
 	exit 1
 fi