Start adding lock code

Author: cwoffenden

test/webaudio/audioworklet_emscripten_locks.cpp

@@ -6,6 +6,7 @@
 #include <assert.h>
 
 // Tests that these audio worklet compatible functions work:
+// - emscripten_thread_supports_atomics_wait()
 // - emscripten_lock_init()
 // - emscripten_lock_busyspin_wait_acquire()
 // - emscripten_lock_busyspin_waitinf_acquire()
@@ -17,9 +18,16 @@ emscripten_lock_t testLock = EMSCRIPTEN_LOCK_T_STATIC_INITIALIZER;
 int testSuccess = 0;
 
 bool ProcessAudio(int numInputs, const AudioSampleFrame *inputs, int numOutputs, AudioSampleFrame *outputs, int numParams, const AudioParamFrame *params, void *userData) {
+  // We're in the audio worklet so no wait support
   int supportsAtomicWait = emscripten_thread_supports_atomics_wait();
   printf("supportsAtomicWait: %d\n", supportsAtomicWait);
   assert(!supportsAtomicWait);
+
+  // Fail to grab the lock 
+  int tryLock = emscripten_lock_try_acquire(&testLock);
+  printf("emscripten_lock_try_acquire: %d\n", tryLock);
+  assert(!tryLock);
+
   //emscripten_futex_wake(&futexLocation, 1);
   printf("%f\n", emscripten_get_now());
 
@@ -67,7 +75,11 @@ void WebAudioWorkletThreadInitialized(EMSCRIPTEN_WEBAUDIO_T audioContext, bool s
 uint8_t wasmAudioWorkletStack[4096];
 
 int main() {
+  // Main thread init and acquire (work passes to the processor)
   emscripten_lock_init(&testLock);
+  int hasLock = emscripten_lock_busyspin_wait_acquire(&testLock, 0);
+  assert(hasLock);
+
   emscripten_set_timeout_loop(PollTestSuccess, 10, 0);
   EMSCRIPTEN_WEBAUDIO_T context = emscripten_create_audio_context(0);
   emscripten_start_wasm_audio_worklet_thread_async(context, wasmAudioWorkletStack, sizeof(wasmAudioWorkletStack), WebAudioWorkletThreadInitialized, 0);