- Fixed a few bugs with ringbuffer, and some cleanup.

- Reworked audio system to use semaphores instead of events for waiting.
  Should fix rare issues where the XAudio2 driver would run out of buffers
  even though it was supposed to be guarded against that.

src/xenia/apu/xaudio2/xaudio2_audio_driver.cc

@@ -20,26 +20,26 @@ namespace xaudio2 {
 
 class XAudio2AudioDriver::VoiceCallback : public IXAudio2VoiceCallback {
  public:
-  VoiceCallback(HANDLE wait_handle) : wait_handle_(wait_handle) {}
+  VoiceCallback(HANDLE semaphore) : semaphore_(semaphore) {}
   ~VoiceCallback() {}
 
   void OnStreamEnd() {}
   void OnVoiceProcessingPassEnd() {}
   void OnVoiceProcessingPassStart(uint32_t samples_required) {}
-  void OnBufferEnd(void* context) { SetEvent(wait_handle_); }
+  void OnBufferEnd(void* context) { assert_true(ReleaseSemaphore(semaphore_, 1, NULL) == TRUE); }
   void OnBufferStart(void* context) {}
   void OnLoopEnd(void* context) {}
   void OnVoiceError(void* context, HRESULT result) {}
 
  private:
-  HANDLE wait_handle_;
+  HANDLE semaphore_;
 };
 
-XAudio2AudioDriver::XAudio2AudioDriver(Emulator* emulator, HANDLE wait)
+XAudio2AudioDriver::XAudio2AudioDriver(Emulator* emulator, HANDLE semaphore)
     : audio_(nullptr),
       mastering_voice_(nullptr),
       pcm_voice_(nullptr),
-      wait_handle_(wait),
+      semaphore_(semaphore),
       voice_callback_(nullptr),
       current_frame_(0),
       AudioDriver(emulator) {}
@@ -61,7 +61,7 @@ const DWORD ChannelMasks[] = {
 void XAudio2AudioDriver::Initialize() {
   HRESULT hr;
 
-  voice_callback_ = new VoiceCallback(wait_handle_);
+  voice_callback_ = new VoiceCallback(semaphore_);
 
   hr = XAudio2Create(&audio_, 0, XAUDIO2_DEFAULT_PROCESSOR);
   if (FAILED(hr)) {
@@ -123,8 +123,6 @@ void XAudio2AudioDriver::Initialize() {
   if (FLAGS_mute) {
     pcm_voice_->SetVolume(0.0f);
   }
-
-  SetEvent(wait_handle_);
 }
 
 void XAudio2AudioDriver::SubmitFrame(uint32_t frame_ptr) {
@@ -169,13 +167,6 @@ void XAudio2AudioDriver::SubmitFrame(uint32_t frame_ptr) {
   // Update playback ratio to our time scalar.
   // This will keep audio in sync with the game clock.
   pcm_voice_->SetFrequencyRatio(float(xe::Clock::guest_time_scalar()));
-
-  XAUDIO2_VOICE_STATE state2;
-  pcm_voice_->GetState(&state2, XAUDIO2_VOICE_NOSAMPLESPLAYED);
-
-  if (state2.BuffersQueued >= frame_count_) {
-    ResetEvent(wait_handle_);
-  }
 }
 
 void XAudio2AudioDriver::Shutdown() {

src/xenia/apu/xaudio2/xaudio2_audio_driver.h

@@ -21,7 +21,7 @@ namespace xaudio2 {
 
 class XAudio2AudioDriver : public AudioDriver {
  public:
-  XAudio2AudioDriver(Emulator* emulator, HANDLE wait);
+  XAudio2AudioDriver(Emulator* emulator, HANDLE semaphore);
   virtual ~XAudio2AudioDriver();
 
   virtual void Initialize();
@@ -32,7 +32,7 @@ class XAudio2AudioDriver : public AudioDriver {
   IXAudio2* audio_;
   IXAudio2MasteringVoice* mastering_voice_;
   IXAudio2SourceVoice* pcm_voice_;
-  HANDLE wait_handle_;
+  HANDLE semaphore_;
 
   class VoiceCallback;
   VoiceCallback* voice_callback_;

src/xenia/apu/xaudio2/xaudio2_audio_system.cc

@@ -25,10 +25,10 @@ XAudio2AudioSystem::~XAudio2AudioSystem() {}
 
 void XAudio2AudioSystem::Initialize() { AudioSystem::Initialize(); }
 
-X_STATUS XAudio2AudioSystem::CreateDriver(size_t index, HANDLE wait,
+X_STATUS XAudio2AudioSystem::CreateDriver(size_t index, HANDLE semaphore,
                                           AudioDriver** out_driver) {
   assert_not_null(out_driver);
-  auto driver = new XAudio2AudioDriver(emulator_, wait);
+  auto driver = new XAudio2AudioDriver(emulator_, semaphore);
   driver->Initialize();
   *out_driver = driver;
   return X_STATUS_SUCCESS;

src/xenia/apu/xaudio2/xaudio2_audio_system.h

@@ -24,7 +24,7 @@ class XAudio2AudioSystem : public AudioSystem {
   XAudio2AudioSystem(Emulator* emulator);
   virtual ~XAudio2AudioSystem();
 
-  virtual X_RESULT CreateDriver(size_t index, HANDLE wait,
+  virtual X_RESULT CreateDriver(size_t index, HANDLE semaphore,
                                 AudioDriver** out_driver);
   virtual void DestroyDriver(AudioDriver* driver);