Fix the WASM Worker cannot start in node.js environment

`emscripten_malloc_wasm_worker` and
`emscripten_create_wasm_worker` functions
adapted to the nodejs environment and
modified the core related tests.

Author: medns

emscripten.py

@@ -890,6 +890,7 @@ def create_pointer_conversion_wrappers(metadata):
     '__main_argc_argv': '__PP',
     'emscripten_stack_set_limits': '_pp',
     '__set_stack_limits': '_pp',
+    '__set_thread_state': '_p___',
     '__cxa_can_catch': '_ppp',
     '__cxa_increment_exception_refcount': '_p',
     '__cxa_decrement_exception_refcount': '_p',

src/library_wasm_worker.js

@@ -47,7 +47,12 @@ addToLibrary({
   $_wasmWorkerRunPostMessage: (e) => {
     // '_wsc' is short for 'wasm call', trying to use an identifier name that
     // will never conflict with user code
-    let data = e.data, wasmCall = data['_wsc'];
+#if ENVIRONMENT_MAY_BE_NODE
+    const data = ENVIRONMENT_IS_NODE ? e : e.data;
+#else
+    const data = e.data;
+#endif
+    const wasmCall = data['_wsc'];
     wasmCall && getWasmTableEntry(wasmCall)(...data['x']);
   },
 
@@ -155,6 +160,12 @@ if (ENVIRONMENT_IS_WASM_WORKER) {
 #endif
       'sb': stackLowestAddress, // sb = stack bottom (lowest stack address, SP points at this when stack is full)
       'sz': stackSize,          // sz = stack size
+#if USE_OFFSET_CONVERTER
+      'wasmOffsetData': wasmOffsetConverter,
+#endif
+#if LOAD_SOURCE_MAP
+      'wasmSourceMapData': wasmSourceMap,
+#endif
     });
     worker.onmessage = _wasmWorkerRunPostMessage;
     return _wasmWorkersID++;

src/parseTools.js

@@ -734,6 +734,18 @@ function runIfMainThread(text) {
   }
 }
 
+function runIfWorkerThread(text) {
+  if (WASM_WORKERS && PTHREADS) {
+    return 'if (ENVIRONMENT_IS_WASM_WORKER || ENVIRONMENT_IS_PTHREAD) { ' + text + ' }';
+  } else if (WASM_WORKERS) {
+    return 'if (ENVIRONMENT_IS_WASM_WORKER) { ' + text + ' }';
+  } else if (PTHREADS) {
+    return 'if (ENVIRONMENT_IS_PTHREAD) { ' + text + ' }';
+  } else {
+    return '';
+  }
+}
+
 // Legacy name for runIfMainThread.
 // TODO(remove).
 const runOnMainThread = runIfMainThread;

src/preamble.js

@@ -226,10 +226,6 @@ function initRuntime() {
 #endif
   runtimeInitialized = true;
 
-#if WASM_WORKERS
-  if (ENVIRONMENT_IS_WASM_WORKER) return _wasmWorkerInitializeRuntime();
-#endif
-
 #if PTHREADS
   if (ENVIRONMENT_IS_PTHREAD) return;
 #endif
@@ -246,6 +242,13 @@ function initRuntime() {
   callRuntimeCallbacks(__RELOC_FUNCS__);
 #endif
   <<< ATINITS >>>
+  
+#if WASM_WORKERS
+if (ENVIRONMENT_IS_WASM_WORKER) {
+  return _wasmWorkerInitializeRuntime();
+}
+#endif
+
   callRuntimeCallbacks(__ATINIT__);
 }
 
@@ -792,7 +795,7 @@ function instantiateSync(file, info) {
 }
 #endif
 
-#if PTHREADS && (LOAD_SOURCE_MAP || USE_OFFSET_CONVERTER)
+#if (PTHREADS || WASM_WORKERS) && (LOAD_SOURCE_MAP || USE_OFFSET_CONVERTER)
 // When using postMessage to send an object, it is processed by the structured
 // clone algorithm.  The prototype, and hence methods, on that object is then
 // lost. This function adds back the lost prototype.  This does not work with
@@ -1090,22 +1093,18 @@ function createWasm() {
   // path.
   if (Module['instantiateWasm']) {
 
-#if USE_OFFSET_CONVERTER && PTHREADS
-    if (ENVIRONMENT_IS_PTHREAD) {
+#if USE_OFFSET_CONVERTER
 #if ASSERTIONS
-      assert(Module['wasmOffsetData'], 'wasmOffsetData not found on Module object');
+{{{ runIfWorkerThread("assert(Module['wasmOffsetData'], 'wasmOffsetData not found on Module object');") }}}
 #endif
-      wasmOffsetConverter = resetPrototype(WasmOffsetConverter, Module['wasmOffsetData']);
-    }
+{{{ runIfWorkerThread("wasmOffsetConverter = resetPrototype(WasmOffsetConverter, Module['wasmOffsetData']);") }}}
 #endif
 
-#if LOAD_SOURCE_MAP && PTHREADS
-    if (ENVIRONMENT_IS_PTHREAD) {
+#if LOAD_SOURCE_MAP
 #if ASSERTIONS
-      assert(Module['wasmSourceMapData'], 'wasmSourceMapData not found on Module object');
+{{{ runIfWorkerThread("assert(Module['wasmSourceMapData'], 'wasmSourceMapData not found on Module object');") }}}
 #endif
-      wasmSourceMap = resetPrototype(WasmSourceMap, Module['wasmSourceMapData']);
-    }
+{{{ runIfWorkerThread("wasmSourceMap = resetPrototype(WasmSourceMap, Module['wasmSourceMapData']);") }}}
 #endif
 
     try {

src/wasm_worker.js

@@ -1,18 +1,51 @@
 // N.B. The contents of this file are duplicated in src/library_wasm_worker.js
 // in variable "_wasmWorkerBlobUrl" (where the contents are pre-minified) If
 // doing any changes to this file, be sure to update the contents there too.
-onmessage = function(d) {
+
+'use strict';
+
+#if ENVIRONMENT_MAY_BE_NODE
+// Node.js support
+var ENVIRONMENT_IS_NODE = typeof process == 'object' && typeof process.versions == 'object' && typeof process.versions.node == 'string';
+if (ENVIRONMENT_IS_NODE) {
+  // Create as web-worker-like an environment as we can.
+
+  var nodeWorkerThreads = require('worker_threads');
+
+  var parentPort = nodeWorkerThreads.parentPort;
+
+  parentPort.on('message', (data) => typeof onmessage === "function" && onmessage({ data: data }));
+
+  var fs = require('fs');
+
+  Object.assign(global, {
+    self: global,
+    require,
+    location: {
+      href: __filename
+    },
+    Worker: nodeWorkerThreads.Worker,
+    importScripts: (f) => (0, eval)(fs.readFileSync(f, 'utf8') + '//# sourceURL=' + f),
+    postMessage: (msg) => parentPort.postMessage(msg),
+    performance: global.performance || { now: Date.now },
+    addEventListener: (name, handler) => parentPort.on(name, handler),
+    removeEventListener: (name, handler) => parentPort.off(name, handler),
+  });
+}
+#endif // ENVIRONMENT_MAY_BE_NODE
+
+self.onmessage = function(d) {
 	// The first message sent to the Worker is always the bootstrap message.
 	// Drop this message listener, it served its purpose of bootstrapping
 	// the Wasm Module load, and is no longer needed. Let user code register
 	// any desired message handlers from now on.
-	onmessage = null;
+	self.onmessage = null;
 	d = d.data;
 #if !MODULARIZE
 	self.{{{ EXPORT_NAME }}} = d;
 #endif
 #if !MINIMAL_RUNTIME
-	d['instantiateWasm'] = (info, receiveInstance) => { var instance = new WebAssembly.Instance(d['wasm'], info); receiveInstance(instance, d['wasm']); return instance.exports; }
+	d['instantiateWasm'] = (info, receiveInstance) => { var instance = new WebAssembly.Instance(d['wasm'], info); return receiveInstance(instance, d['wasm']); }
 #endif
 	importScripts(d.js);
 #if MODULARIZE

test/code_size/hello_wasm_worker_wasm.js

@@ -4,7 +4,7 @@ var b = Module, c = b.$ww, e = b.mem || new WebAssembly.Memory({
     shared: !0
 }), f = e.buffer, g = [], h, k = a => {
     a = a.data;
-    let d = a._wsc;
+    const d = a._wsc;
     d && h.get(d)(...a.x);
 }, l = a => {
     g.push(a);

test/code_size/hello_wasm_worker_wasm.json

@@ -1,10 +1,10 @@
 {
   "a.html": 737,
   "a.html.gz": 433,
-  "a.js": 667,
-  "a.js.gz": 458,
+  "a.js": 669,
+  "a.js.gz": 460,
   "a.wasm": 1862,
   "a.wasm.gz": 1040,
-  "total": 3266,
-  "total_gz": 1931
+  "total": 3268,
+  "total_gz": 1933
 }

test/common.py

@@ -1064,7 +1064,8 @@ def cleanup(line):
   def run_js(self, filename, engine=None, args=None,
              output_nicerizer=None,
              assert_returncode=0,
-             interleaved_output=True):
+             interleaved_output=True,
+             timeout=None, timeout_as_error=True):
     # use files, as PIPE can get too full and hang us
     stdout_file = self.in_dir('stdout')
     stderr_file = None
@@ -1086,9 +1087,11 @@ def run_js(self, filename, engine=None, args=None,
       jsrun.run_js(filename, engine, args,
                    stdout=stdout,
                    stderr=stderr,
-                   assert_returncode=assert_returncode)
+                   assert_returncode=assert_returncode,
+                   timeout=timeout)
     except subprocess.TimeoutExpired as e:
-      timeout_error = e
+      if timeout_as_error:
+        timeout_error = e
     except subprocess.CalledProcessError as e:
       error = e
     finally:
@@ -1506,7 +1509,8 @@ def _build_and_run(self, filename, expected_output, args=None, output_nicerizer=
                      check_for_error=True, force_c=False, emcc_args=None,
                      interleaved_output=True,
                      regex=False,
-                     output_basename=None):
+                     output_basename=None,
+                     timeout=None, timeout_as_error=True):
     logger.debug(f'_build_and_run: {filename}')
 
     if no_build:
@@ -1533,7 +1537,9 @@ def _build_and_run(self, filename, expected_output, args=None, output_nicerizer=
       js_output = self.run_js(js_file, engine, args,
                               output_nicerizer=output_nicerizer,
                               assert_returncode=assert_returncode,
-                              interleaved_output=interleaved_output)
+                              interleaved_output=interleaved_output,
+                              timeout=timeout,
+                              timeout_as_error=timeout_as_error)
       js_output = js_output.replace('\r\n', '\n')
       if expected_output:
         if type(expected_output) not in [list, tuple]:

test/test_core.py

@@ -9795,15 +9795,15 @@ def test_emscripten_async_load_script(self):
 
   @node_pthreads
   def test_wasm_worker_hello(self):
-    self.do_runf(test_file('wasm_worker/hello_wasm_worker.c'), emcc_args=['-sWASM_WORKERS'])
+    self.do_run_in_out_file_test(test_file('wasm_worker/hello_wasm_worker.c'), emcc_args=['-sWASM_WORKERS'], timeout=3, timeout_as_error=False)
 
   @node_pthreads
   def test_wasm_worker_malloc(self):
-    self.do_runf(test_file('wasm_worker/malloc_wasm_worker.c'), emcc_args=['-sWASM_WORKERS'])
+    self.do_run_in_out_file_test(test_file('wasm_worker/malloc_wasm_worker.c'), emcc_args=['-sWASM_WORKERS'], timeout=3, timeout_as_error=False)
 
   @node_pthreads
   def test_wasm_worker_wait_async(self):
-    self.do_runf(test_file('wasm_worker/wait_async.c'), emcc_args=['-sWASM_WORKERS'])
+    self.do_runf(test_file('wasm_worker/wait_async.c'), emcc_args=['-sWASM_WORKERS'], timeout=3, timeout_as_error=False)
 
 
 # Generate tests for everything

test/wasm_worker/hello_wasm_worker.out

@@ -0,0 +1 @@
+Hello from wasm worker!

test/wasm_worker/malloc_wasm_worker.out

@@ -0,0 +1 @@
+Hello from wasm worker!