Avoid calling addEventListener in audio worklet (#21897)

Author: m4burns

src/library_wasm_worker.js

@@ -143,7 +143,12 @@ addToLibrary({
 #endif
   ],
   _emscripten_create_wasm_worker__postset: `
-if (ENVIRONMENT_IS_WASM_WORKER) {
+if (ENVIRONMENT_IS_WASM_WORKER
+// AudioWorkletGlobalScope does not contain addEventListener
+#if AUDIO_WORKLET
+  && !ENVIRONMENT_IS_AUDIO_WORKLET
+#endif
+  ) {
   _wasmWorkers[0] = this;
   addEventListener("message", _wasmWorkerAppendToQueue);
 }`,

test/test_browser.py

@@ -5479,6 +5479,13 @@ def test_audio_worklet(self, args):
       self.skipTest('https://github.com/emscripten-core/emscripten/issues/19161')
     self.btest_exit('webaudio/audioworklet.c', args=['-sAUDIO_WORKLET', '-sWASM_WORKERS'] + args)
 
+  # Tests that audioworklets and workers can be used at the same time
+  @parameterized({
+    '': ([],),
+  })
+  def test_audio_worklet_worker(self, args):
+    self.btest('webaudio/audioworklet_worker.c', args=['-sAUDIO_WORKLET', '-sWASM_WORKERS'] + args, expected='1')
+
   # Tests that posting functions between the main thread and the audioworklet thread works
   @parameterized({
     '': ([],),

test/webaudio/audioworklet_worker.c

@@ -0,0 +1,48 @@
+#include <emscripten/webaudio.h>
+#include <emscripten/wasm_worker.h>
+#include <emscripten/threading.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+// Tests that
+// - audioworklets and workers can be used at the same time.
+// - an audioworklet can emscripten_futex_wake() a waiting worker.
+// - global values can be shared between audioworklets and workers.
+
+int workletToWorkerFutexLocation = 0;
+int workletToWorkerFlag = 0;
+
+void run_in_worker() {
+  while (0 == emscripten_futex_wait(&workletToWorkerFutexLocation, 0, 30000)) {
+    if (workletToWorkerFlag == 1) {
+      printf("Test success\n");
+      break;
+    }
+  }
+
+#ifdef REPORT_RESULT
+  REPORT_RESULT(workletToWorkerFlag == 1);
+#endif
+}
+
+// This event will fire on the audio worklet thread.
+void MessageReceivedInAudioWorkletThread() {
+  assert(emscripten_current_thread_is_audio_worklet());
+  workletToWorkerFlag = 1;
+  emscripten_futex_wake(&workletToWorkerFutexLocation, 1);
+}
+
+void WebAudioWorkletThreadInitialized(EMSCRIPTEN_WEBAUDIO_T audioContext, EM_BOOL success, void *userData) {
+  emscripten_audio_worklet_post_function_v(audioContext, MessageReceivedInAudioWorkletThread);
+}
+
+uint8_t wasmAudioWorkletStack[4096];
+
+int main() {
+  emscripten_wasm_worker_t worker = emscripten_malloc_wasm_worker(/*stackSize: */1024);
+  emscripten_wasm_worker_post_function_v(worker, run_in_worker);
+
+  EMSCRIPTEN_WEBAUDIO_T context = emscripten_create_audio_context(0);
+  emscripten_start_wasm_audio_worklet_thread_async(context, wasmAudioWorkletStack, sizeof(wasmAudioWorkletStack), WebAudioWorkletThreadInitialized, 0);
+}