[AUDIO_WORKLETS] Move code off the main thread in locks test

test/test_browser.py

@@ -5500,7 +5500,6 @@ def test_audio_worklet_params_mixing(self, args):
   # Tests AudioWorklet with emscripten_lock_busyspin_wait_acquire() and friends
   @requires_sound_hardware
   @also_with_minimal_runtime
-  @flaky('https://github.com/emscripten-core/emscripten/issues/25245')
   def test_audio_worklet_emscripten_locks(self):
     self.btest_exit('webaudio/audioworklet_emscripten_locks.c', cflags=['-sAUDIO_WORKLET', '-sWASM_WORKERS', '-pthread'])
 

test/webaudio/audioworklet_emscripten_locks.c

@@ -13,11 +13,16 @@
 // - emscripten_lock_release()
 // - emscripten_get_now()
 
+// Global audio context
+EMSCRIPTEN_WEBAUDIO_T context;
+
 // Internal, found in 'system/lib/pthread/threading_internal.h' (and requires building with -pthread)
 int _emscripten_thread_supports_atomics_wait(void);
 
 typedef enum {
-  // No wait support in audio worklets
+  // The test hasn't yet started
+  TEST_NOT_STARTED,
+  // No atomics wait support in audio worklets
   TEST_HAS_WAIT,
   // Acquired in main, fail in process
   TEST_TRY_ACQUIRE,
@@ -39,27 +44,25 @@ typedef enum {
 
 // Lock used in all the tests
 emscripten_lock_t testLock = EMSCRIPTEN_LOCK_T_STATIC_INITIALIZER;
-// Which test is running (sometimes in the worklet, sometimes in the main thread)
-_Atomic Test whichTest = TEST_HAS_WAIT;
+// Which test is running (sometimes in the worklet, sometimes in the worker)
+_Atomic Test whichTest = TEST_NOT_STARTED;
 // Time at which the test starts taken in main()
 double startTime = 0;
 
+void do_exit() {
+  emscripten_out("Test success");
+  emscripten_destroy_audio_context(context);
+  emscripten_terminate_all_wasm_workers();
+  emscripten_force_exit(0);
+}
+
 bool ProcessAudio(int numInputs, const AudioSampleFrame *inputs, int numOutputs, AudioSampleFrame *outputs, int numParams, const AudioParamFrame *params, void *userData) {
   assert(emscripten_current_thread_is_audio_worklet());
 
-  // Produce at few empty frames of audio before we start trying to interact
-  // with the with main thread.
-  // On chrome at least it appears the main thread completely blocks until
-  // a few frames have been produced.  This means it may not be safe to interact
-  // with the main thread during initial frames?
-  // In my experiments it seems like 5 was the magic number that I needed to
-  // produce before the main thread could continue to run.
-  // See https://github.com/emscripten-core/emscripten/issues/24213
-  static int count = 0;
-  if (count++ < 5) return true;
-
   int result = 0;
   switch (whichTest) {
+  case TEST_NOT_STARTED:
+    break;
   case TEST_HAS_WAIT:
     // Should not have wait support here
     result = _emscripten_thread_supports_atomics_wait();
@@ -80,8 +83,9 @@ bool ProcessAudio(int numInputs, const AudioSampleFrame *inputs, int numOutputs,
     emscripten_outf("TEST_WAIT_ACQUIRE_FAIL: %d (expect: 0)", result);
     assert(!result);
     whichTest = TEST_WAIT_ACQUIRE;
+    // Fall through here so the worker has a chance to unlock whilst spinning
   case TEST_WAIT_ACQUIRE:
-    // Will get unlocked in main thread, so should quickly acquire
+    // Will get unlocked in worker, so should quickly acquire
     result = emscripten_lock_busyspin_wait_acquire(&testLock, 10000);
     emscripten_outf("TEST_WAIT_ACQUIRE: %d  (expect: 1)", result);
     assert(result);
@@ -96,7 +100,7 @@ bool ProcessAudio(int numInputs, const AudioSampleFrame *inputs, int numOutputs,
     whichTest = TEST_WAIT_INFINTE_1;
     break;
   case TEST_WAIT_INFINTE_1:
-    // Still locked when we enter here but move on in the main thread
+    // Still locked when we enter here but move on in the worker
     break;
   case TEST_WAIT_INFINTE_2:
     emscripten_lock_release(&testLock);
@@ -107,6 +111,7 @@ bool ProcessAudio(int numInputs, const AudioSampleFrame *inputs, int numOutputs,
     emscripten_outf("TEST_GET_NOW: %d  (expect: > 0)", result);
     assert(result > 0);
     whichTest = TEST_DONE;
+    // Fall through here and stop playback (shutting down in the worker)
   case TEST_DONE:
     return false;
   default:
@@ -126,33 +131,39 @@ EM_JS(void, InitHtmlUi, (EMSCRIPTEN_WEBAUDIO_T audioContext), {
   };
 });
 
-bool MainLoop(double time, void* data) {
+void WorkerLoop() {
   assert(!emscripten_current_thread_is_audio_worklet());
-  static int didUnlock = false;
-  switch (whichTest) {
-  case TEST_WAIT_ACQUIRE:
-    if (!didUnlock) {
-      emscripten_out("main thread releasing lock");
-      // Release here to acquire in process
-      emscripten_lock_release(&testLock);
-      didUnlock = true;
-    }
-    break;
-  case TEST_WAIT_INFINTE_1:
-    // Spin here until released in process (but don't change test until we know this case ran)
-    whichTest = TEST_WAIT_INFINTE_2;
-    emscripten_lock_busyspin_waitinf_acquire(&testLock);
-    emscripten_out("TEST_WAIT_INFINTE (from main)");
-    break;
-  case TEST_DONE:
-    // Finished, exit from the main thread
-    emscripten_out("Test success");
-    emscripten_force_exit(0);
-    return false;
-  default:
-    break;
+  int didUnlock = false;
+  while (true) {
+	  switch (whichTest) {
+	  case TEST_NOT_STARTED:
+		emscripten_out("Staring test (may need a button click)");
+		whichTest = TEST_HAS_WAIT;
+		break;
+	  case TEST_WAIT_ACQUIRE:
+		if (!didUnlock) {
+		  emscripten_out("Worker releasing lock");
+		  // Release here to acquire in process
+		  emscripten_lock_release(&testLock);
+		  didUnlock = true;
+		}
+		break;
+	  case TEST_WAIT_INFINTE_1:
+		// Spin here until released in process (but don't change test until we know this case ran)
+		whichTest = TEST_WAIT_INFINTE_2;
+		emscripten_lock_busyspin_waitinf_acquire(&testLock);
+		emscripten_out("TEST_WAIT_INFINTE (from worker)");
+		break;
+	  case TEST_DONE:
+		// Finished, exit from the main thread (and return out of this loop)
+		emscripten_wasm_worker_post_function_v(EMSCRIPTEN_WASM_WORKER_ID_PARENT, &do_exit);
+		return;
+	  default:
+		break;
+	  }
+	  // Repeat every 16ms (except when TEST_DONE)
+	  emscripten_wasm_worker_sleep(16 * 1000000ULL);
   }
-  return true;
 }
 
 void AudioWorkletProcessorCreated(EMSCRIPTEN_WEBAUDIO_T audioContext, bool success, void *userData) {
@@ -171,16 +182,21 @@ void WebAudioWorkletThreadInitialized(EMSCRIPTEN_WEBAUDIO_T audioContext, bool s
 uint8_t wasmAudioWorkletStack[2048];
 
 int main() {
-  // Main thread init and acquire (work passes to the processor)
+  // Main thread init and acquire (work passes to the audio processor)
   emscripten_lock_init(&testLock);
   int hasLock = emscripten_lock_busyspin_wait_acquire(&testLock, 0);
   assert(hasLock);
 
   startTime = emscripten_get_now();
 
-  emscripten_set_timeout_loop(MainLoop, 10, NULL);
-  EMSCRIPTEN_WEBAUDIO_T context = emscripten_create_audio_context(NULL);
+  // Audio processor callback setup
+  context = emscripten_create_audio_context(NULL);
+  assert(context);
   emscripten_start_wasm_audio_worklet_thread_async(context, wasmAudioWorkletStack, sizeof(wasmAudioWorkletStack), WebAudioWorkletThreadInitialized, NULL);
+
+  // Worker thread setup
+  emscripten_wasm_worker_t worker = emscripten_malloc_wasm_worker(1024);
+  emscripten_wasm_worker_post_function_v(worker, WorkerLoop);
 
   emscripten_exit_with_live_runtime();
 }