Sync to audio by default

src/gba/gba-audio.c

@@ -2,8 +2,9 @@
 
 #include "gba.h"
 #include "gba-io.h"
+#include "gba-thread.h"
 
-const unsigned GBA_AUDIO_SAMPLES = 1024;
+const unsigned GBA_AUDIO_SAMPLES = 512;
 const unsigned GBA_AUDIO_FIFO_SIZE = 8 * sizeof(int32_t);
 
 static void _sample(struct GBAAudio* audio);
@@ -176,6 +177,9 @@ static void _sample(struct GBAAudio* audio) {
 	}
 
 	pthread_mutex_lock(&audio->bufferMutex);
+	while (CircleBufferSize(&audio->left) + (GBA_AUDIO_SAMPLES * 2 / 5) >= audio->left.capacity) {
+		GBASyncProduceAudio(audio->p->sync, &audio->bufferMutex);
+	}
 	CircleBufferWrite32(&audio->left, sampleLeft);
 	CircleBufferWrite32(&audio->right, sampleRight);
 	pthread_mutex_unlock(&audio->bufferMutex);

src/gba/gba-thread.c

@@ -92,6 +92,8 @@ int GBAThreadStart(struct GBAThread* threadContext) {
 	pthread_mutex_init(&threadContext->sync.videoFrameMutex, 0);
 	pthread_cond_init(&threadContext->sync.videoFrameAvailableCond, 0);
 	pthread_cond_init(&threadContext->sync.videoFrameRequiredCond, 0);
+	pthread_cond_init(&threadContext->sync.audioAvailableCond, 0);
+	pthread_cond_init(&threadContext->sync.audioRequiredCond, 0);
 
 	pthread_mutex_lock(&threadContext->startMutex);
 	threadContext->activeKeys = 0;
@@ -119,6 +121,11 @@ void GBAThreadJoin(struct GBAThread* threadContext) {
 	pthread_cond_destroy(&threadContext->sync.videoFrameAvailableCond);
 	pthread_cond_broadcast(&threadContext->sync.videoFrameRequiredCond);
 	pthread_cond_destroy(&threadContext->sync.videoFrameRequiredCond);
+
+	pthread_cond_broadcast(&threadContext->sync.audioAvailableCond);
+	pthread_cond_destroy(&threadContext->sync.audioAvailableCond);
+	pthread_cond_broadcast(&threadContext->sync.audioRequiredCond);
+	pthread_cond_destroy(&threadContext->sync.audioRequiredCond);
 }
 
 struct GBAThread* GBAThreadGetContext(void) {
@@ -163,3 +170,14 @@ void GBASyncWaitFrameEnd(struct GBASync* sync) {
 int GBASyncDrawingFrame(struct GBASync* sync) {
 	return sync->videoFrameSkip <= 0;
 }
+
+void GBASyncProduceAudio(struct GBASync* sync, pthread_mutex_t* mutex) {
+	pthread_cond_broadcast(&sync->audioAvailableCond);
+	if (&sync->audioWait) {
+		pthread_cond_wait(&sync->audioRequiredCond, mutex);
+	}
+}
+
+void GBASyncConsumeAudio(struct GBASync* sync) {
+	pthread_cond_broadcast(&sync->audioRequiredCond);
+}

src/gba/gba-thread.h

@@ -30,6 +30,10 @@ struct GBAThread {
 		pthread_mutex_t videoFrameMutex;
 		pthread_cond_t videoFrameAvailableCond;
 		pthread_cond_t videoFrameRequiredCond;
+
+		int audioWait;
+		pthread_cond_t audioAvailableCond;
+		pthread_cond_t audioRequiredCond;
 	} sync;
 };
 
@@ -42,4 +46,7 @@ void GBASyncWaitFrameStart(struct GBASync* sync, int frameskip);
 void GBASyncWaitFrameEnd(struct GBASync* sync);
 int GBASyncDrawingFrame(struct GBASync* sync);
 
+void GBASyncProduceAudio(struct GBASync* sync, pthread_mutex_t* mutex);
+void GBASyncConsumeAudio(struct GBASync* sync);
+
 #endif

src/gl-main.c

@@ -72,6 +72,8 @@ int main(int argc, char** argv) {
 	context.useDebugger = 1;
 	context.renderer = &renderer.d.d;
 	context.frameskip = 0;
+	context.sync.videoFrameWait = 0;
+	context.sync.audioWait = 1;
 	GBAThreadStart(&context);
 	renderer.audio.audio = &context.gba->audio;
 

src/sdl/sdl-audio.c

@@ -1,6 +1,7 @@
 #include "sdl-audio.h"
 
 #include "gba.h"
+#include "gba-thread.h"
 
 static void _GBASDLAudioCallback(void* context, Uint8* data, int len);
 
@@ -67,6 +68,7 @@ static void _GBASDLAudioCallback(void* context, Uint8* data, int len) {
 			}
 			ssamples[i] = audioContext->currentSample;
 		}
+		GBASyncConsumeAudio(audioContext->audio->p->sync);
 		pthread_mutex_unlock(&audioContext->audio->bufferMutex);
 	}
 }

src/sdl/sdl-events.c

@@ -52,7 +52,7 @@ static void _GBASDLHandleKeypress(struct GBAThread* context, const struct SDL_Ke
 		key = GBA_KEY_RIGHT;
 		break;
 	case SDLK_TAB:
-		context->sync.videoFrameWait = !context->sync.videoFrameWait;
+		context->sync.audioWait = !context->sync.audioWait;
 		return;
 	default:
 		return;