all repos — mgba @ 4fdb4991f4552001a42b4200d8ff3d83ef1279ea

mGBA Game Boy Advance Emulator

src/gba/gba-thread.c (view raw)

  1/* Copyright (c) 2013-2014 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include "gba-thread.h"
  7
  8#include "arm.h"
  9#include "gba.h"
 10#include "gba-config.h"
 11#include "gba-serialize.h"
 12
 13#include "debugger/debugger.h"
 14
 15#include "util/patch.h"
 16#include "util/png-io.h"
 17#include "util/vfs.h"
 18
 19#include "platform/commandline.h"
 20
 21#include <signal.h>
 22
 23static const float _defaultFPSTarget = 60.f;
 24
 25#ifdef USE_PTHREADS
 26static pthread_key_t _contextKey;
 27static pthread_once_t _contextOnce = PTHREAD_ONCE_INIT;
 28
 29static void _createTLS(void) {
 30	pthread_key_create(&_contextKey, 0);
 31}
 32#elif _WIN32
 33static DWORD _contextKey;
 34static INIT_ONCE _contextOnce = INIT_ONCE_STATIC_INIT;
 35
 36static BOOL CALLBACK _createTLS(PINIT_ONCE once, PVOID param, PVOID* context) {
 37	UNUSED(once);
 38	UNUSED(param);
 39	UNUSED(context);
 40	_contextKey = TlsAlloc();
 41	return TRUE;
 42}
 43#endif
 44
 45#ifndef DISABLE_THREADING
 46static void _changeState(struct GBAThread* threadContext, enum ThreadState newState, bool broadcast) {
 47	MutexLock(&threadContext->stateMutex);
 48	threadContext->state = newState;
 49	if (broadcast) {
 50		ConditionWake(&threadContext->stateCond);
 51	}
 52	MutexUnlock(&threadContext->stateMutex);
 53}
 54
 55static void _waitOnInterrupt(struct GBAThread* threadContext) {
 56	while (threadContext->state == THREAD_INTERRUPTED) {
 57		ConditionWait(&threadContext->stateCond, &threadContext->stateMutex);
 58	}
 59}
 60
 61static void _waitUntilNotState(struct GBAThread* threadContext, enum ThreadState oldState) {
 62	while (threadContext->state == oldState) {
 63		MutexUnlock(&threadContext->stateMutex);
 64
 65		MutexLock(&threadContext->sync.videoFrameMutex);
 66		ConditionWake(&threadContext->sync.videoFrameRequiredCond);
 67		MutexUnlock(&threadContext->sync.videoFrameMutex);
 68
 69		MutexLock(&threadContext->sync.audioBufferMutex);
 70		ConditionWake(&threadContext->sync.audioRequiredCond);
 71		MutexUnlock(&threadContext->sync.audioBufferMutex);
 72
 73		MutexLock(&threadContext->stateMutex);
 74		ConditionWake(&threadContext->stateCond);
 75	}
 76}
 77
 78static void _pauseThread(struct GBAThread* threadContext, bool onThread) {
 79	if (threadContext->debugger && threadContext->debugger->state == DEBUGGER_RUNNING) {
 80		threadContext->debugger->state = DEBUGGER_EXITING;
 81	}
 82	threadContext->state = THREAD_PAUSING;
 83	if (!onThread) {
 84		_waitUntilNotState(threadContext, THREAD_PAUSING);
 85	}
 86}
 87#endif
 88
 89static void _changeVideoSync(struct GBASync* sync, bool frameOn) {
 90	// Make sure the video thread can process events while the GBA thread is paused
 91	MutexLock(&sync->videoFrameMutex);
 92	if (frameOn != sync->videoFrameOn) {
 93		sync->videoFrameOn = frameOn;
 94		ConditionWake(&sync->videoFrameAvailableCond);
 95	}
 96	MutexUnlock(&sync->videoFrameMutex);
 97}
 98
 99#ifndef DISABLE_THREADING
100static THREAD_ENTRY _GBAThreadRun(void* context) {
101#ifdef USE_PTHREADS
102	pthread_once(&_contextOnce, _createTLS);
103#else
104	InitOnceExecuteOnce(&_contextOnce, _createTLS, NULL, 0);
105#endif
106
107	struct GBA gba;
108	struct ARMCore cpu;
109	struct Patch patch;
110	struct GBAThread* threadContext = context;
111	struct ARMComponent* components[1] = {};
112	int numComponents = 0;
113
114	if (threadContext->debugger) {
115		components[numComponents] = &threadContext->debugger->d;
116		++numComponents;
117	}
118
119#if !defined(_WIN32) && defined(USE_PTHREADS)
120	sigset_t signals;
121	sigemptyset(&signals);
122	pthread_sigmask(SIG_SETMASK, &signals, 0);
123#endif
124
125	GBACreate(&gba);
126	ARMSetComponents(&cpu, &gba.d, numComponents, components);
127	ARMInit(&cpu);
128	gba.sync = &threadContext->sync;
129	threadContext->gba = &gba;
130	gba.logLevel = threadContext->logLevel;
131#ifdef USE_PTHREADS
132	pthread_setspecific(_contextKey, threadContext);
133#else
134	TlsSetValue(_contextKey, threadContext);
135#endif
136
137	if (threadContext->audioBuffers) {
138		GBAAudioResizeBuffer(&gba.audio, threadContext->audioBuffers);
139	} else {
140		threadContext->audioBuffers = GBA_AUDIO_SAMPLES;
141	}
142
143	if (threadContext->renderer) {
144		GBAVideoAssociateRenderer(&gba.video, threadContext->renderer);
145	}
146
147	if (threadContext->rom) {
148		GBALoadROM(&gba, threadContext->rom, threadContext->save, threadContext->fname);
149		if (threadContext->bios && GBAIsBIOS(threadContext->bios)) {
150			GBALoadBIOS(&gba, threadContext->bios);
151		}
152
153		if (threadContext->patch && loadPatch(threadContext->patch, &patch)) {
154			GBAApplyPatch(&gba, &patch);
155		}
156	}
157
158	ARMReset(&cpu);
159	if (threadContext->skipBios) {
160		GBASkipBIOS(&cpu);
161	}
162
163	if (threadContext->debugger) {
164		threadContext->debugger->log = GBADebuggerLogShim;
165		GBAAttachDebugger(&gba, threadContext->debugger);
166		ARMDebuggerEnter(threadContext->debugger, DEBUGGER_ENTER_ATTACHED);
167	}
168
169	GBASIOSetDriverSet(&gba.sio, &threadContext->sioDrivers);
170
171	gba.keySource = &threadContext->activeKeys;
172
173	if (threadContext->startCallback) {
174		threadContext->startCallback(threadContext);
175	}
176
177	_changeState(threadContext, THREAD_RUNNING, true);
178
179	while (threadContext->state < THREAD_EXITING) {
180		if (threadContext->debugger) {
181			struct ARMDebugger* debugger = threadContext->debugger;
182			ARMDebuggerRun(debugger);
183			if (debugger->state == DEBUGGER_SHUTDOWN) {
184				_changeState(threadContext, THREAD_EXITING, false);
185			}
186		} else {
187			while (threadContext->state == THREAD_RUNNING) {
188				ARMRunLoop(&cpu);
189			}
190		}
191
192		int resetScheduled = 0;
193		MutexLock(&threadContext->stateMutex);
194		while (threadContext->state > THREAD_RUNNING && threadContext->state < THREAD_EXITING) {
195			if (threadContext->state == THREAD_PAUSING) {
196				threadContext->state = THREAD_PAUSED;
197				ConditionWake(&threadContext->stateCond);
198			}
199			if (threadContext->state == THREAD_INTERRUPTING) {
200				threadContext->state = THREAD_INTERRUPTED;
201				ConditionWake(&threadContext->stateCond);
202			}
203			if (threadContext->state == THREAD_RESETING) {
204				threadContext->state = THREAD_RUNNING;
205				resetScheduled = 1;
206			}
207			while (threadContext->state == THREAD_PAUSED || threadContext->state == THREAD_INTERRUPTED) {
208				ConditionWait(&threadContext->stateCond, &threadContext->stateMutex);
209			}
210		}
211		MutexUnlock(&threadContext->stateMutex);
212		if (resetScheduled) {
213			ARMReset(&cpu);
214			if (threadContext->skipBios) {
215				GBASkipBIOS(&cpu);
216			}
217		}
218	}
219
220	while (threadContext->state != THREAD_SHUTDOWN) {
221		_changeState(threadContext, THREAD_SHUTDOWN, false);
222	}
223
224	if (threadContext->cleanCallback) {
225		threadContext->cleanCallback(threadContext);
226	}
227
228	threadContext->gba = 0;
229	ARMDeinit(&cpu);
230	GBADestroy(&gba);
231
232	threadContext->sync.videoFrameOn = false;
233	ConditionWake(&threadContext->sync.videoFrameAvailableCond);
234	ConditionWake(&threadContext->sync.audioRequiredCond);
235
236	return 0;
237}
238
239void GBAMapOptionsToContext(const struct GBAOptions* opts, struct GBAThread* threadContext) {
240	threadContext->bios = VFileOpen(opts->bios, O_RDONLY);
241	threadContext->frameskip = opts->frameskip;
242	threadContext->logLevel = opts->logLevel;
243	threadContext->rewindBufferCapacity = opts->rewindBufferCapacity;
244	threadContext->rewindBufferInterval = opts->rewindBufferInterval;
245	threadContext->skipBios = opts->skipBios;
246	threadContext->sync.audioWait = opts->audioSync;
247	threadContext->sync.videoFrameWait = opts->videoSync;
248
249	if (opts->fpsTarget) {
250		threadContext->fpsTarget = opts->fpsTarget;
251	}
252
253	if (opts->audioBuffers) {
254		threadContext->audioBuffers = opts->audioBuffers;
255	}
256}
257
258void GBAMapArgumentsToContext(const struct GBAArguments* args, struct GBAThread* threadContext) {
259	if (args->dirmode) {
260		threadContext->gameDir = VDirOpen(args->fname);
261		threadContext->stateDir = threadContext->gameDir;
262	} else {
263		threadContext->rom = VFileOpen(args->fname, O_RDONLY);
264#if ENABLE_LIBZIP
265		threadContext->gameDir = VDirOpenZip(args->fname, 0);
266#endif
267	}
268	threadContext->fname = args->fname;
269	threadContext->patch = VFileOpen(args->patch, O_RDONLY);
270}
271
272bool GBAThreadStart(struct GBAThread* threadContext) {
273	// TODO: error check
274	threadContext->activeKeys = 0;
275	threadContext->state = THREAD_INITIALIZED;
276	threadContext->sync.videoFrameOn = true;
277	threadContext->sync.videoFrameSkip = 0;
278
279	threadContext->rewindBufferNext = threadContext->rewindBufferInterval;
280	threadContext->rewindBufferSize = 0;
281	if (threadContext->rewindBufferCapacity) {
282		threadContext->rewindBuffer = calloc(threadContext->rewindBufferCapacity, sizeof(void*));
283	} else {
284		threadContext->rewindBuffer = 0;
285	}
286
287	if (!threadContext->fpsTarget) {
288		threadContext->fpsTarget = _defaultFPSTarget;
289	}
290
291	if (threadContext->rom && !GBAIsROM(threadContext->rom)) {
292		threadContext->rom->close(threadContext->rom);
293		threadContext->rom = 0;
294	}
295
296	if (threadContext->gameDir) {
297		threadContext->gameDir->rewind(threadContext->gameDir);
298		struct VDirEntry* dirent = threadContext->gameDir->listNext(threadContext->gameDir);
299		while (dirent) {
300			struct Patch patchTemp;
301			struct VFile* vf = threadContext->gameDir->openFile(threadContext->gameDir, dirent->name(dirent), O_RDONLY);
302			if (!vf) {
303				continue;
304			}
305			if (!threadContext->rom && GBAIsROM(vf)) {
306				threadContext->rom = vf;
307			} else if (!threadContext->patch && loadPatch(vf, &patchTemp)) {
308				threadContext->patch = vf;
309			} else {
310				vf->close(vf);
311			}
312			dirent = threadContext->gameDir->listNext(threadContext->gameDir);
313		}
314
315	}
316
317	if (!threadContext->rom) {
318		threadContext->state = THREAD_SHUTDOWN;
319		return false;
320	}
321
322	threadContext->save = VDirOptionalOpenFile(threadContext->stateDir, threadContext->fname, "sram", ".sav", O_CREAT | O_RDWR);
323
324	MutexInit(&threadContext->stateMutex);
325	ConditionInit(&threadContext->stateCond);
326
327	MutexInit(&threadContext->sync.videoFrameMutex);
328	ConditionInit(&threadContext->sync.videoFrameAvailableCond);
329	ConditionInit(&threadContext->sync.videoFrameRequiredCond);
330	MutexInit(&threadContext->sync.audioBufferMutex);
331	ConditionInit(&threadContext->sync.audioRequiredCond);
332
333	threadContext->interruptDepth = 0;
334
335#ifndef _WIN32
336	sigset_t signals;
337	sigemptyset(&signals);
338	sigaddset(&signals, SIGINT);
339	sigaddset(&signals, SIGTRAP);
340	pthread_sigmask(SIG_BLOCK, &signals, 0);
341#endif
342
343	MutexLock(&threadContext->stateMutex);
344	ThreadCreate(&threadContext->thread, _GBAThreadRun, threadContext);
345	while (threadContext->state < THREAD_RUNNING) {
346		ConditionWait(&threadContext->stateCond, &threadContext->stateMutex);
347	}
348	MutexUnlock(&threadContext->stateMutex);
349
350	return true;
351}
352
353bool GBAThreadHasStarted(struct GBAThread* threadContext) {
354	bool hasStarted;
355	MutexLock(&threadContext->stateMutex);
356	hasStarted = threadContext->state > THREAD_INITIALIZED;
357	MutexUnlock(&threadContext->stateMutex);
358	return hasStarted;
359}
360
361void GBAThreadEnd(struct GBAThread* threadContext) {
362	MutexLock(&threadContext->stateMutex);
363	if (threadContext->debugger && threadContext->debugger->state == DEBUGGER_RUNNING) {
364		threadContext->debugger->state = DEBUGGER_EXITING;
365	}
366	threadContext->state = THREAD_EXITING;
367	if (threadContext->gba) {
368		threadContext->gba->cpu->halted = false;
369	}
370	ConditionWake(&threadContext->stateCond);
371	MutexUnlock(&threadContext->stateMutex);
372	MutexLock(&threadContext->sync.audioBufferMutex);
373	threadContext->sync.audioWait = 0;
374	ConditionWake(&threadContext->sync.audioRequiredCond);
375	MutexUnlock(&threadContext->sync.audioBufferMutex);
376
377	MutexLock(&threadContext->sync.videoFrameMutex);
378	threadContext->sync.videoFrameWait = false;
379	threadContext->sync.videoFrameOn = false;
380	ConditionWake(&threadContext->sync.videoFrameRequiredCond);
381	ConditionWake(&threadContext->sync.videoFrameAvailableCond);
382	MutexUnlock(&threadContext->sync.videoFrameMutex);
383}
384
385void GBAThreadReset(struct GBAThread* threadContext) {
386	MutexLock(&threadContext->stateMutex);
387	_waitOnInterrupt(threadContext);
388	threadContext->state = THREAD_RESETING;
389	ConditionWake(&threadContext->stateCond);
390	MutexUnlock(&threadContext->stateMutex);
391}
392
393void GBAThreadJoin(struct GBAThread* threadContext) {
394	ThreadJoin(threadContext->thread);
395
396	MutexDeinit(&threadContext->stateMutex);
397	ConditionDeinit(&threadContext->stateCond);
398
399	MutexDeinit(&threadContext->sync.videoFrameMutex);
400	ConditionWake(&threadContext->sync.videoFrameAvailableCond);
401	ConditionDeinit(&threadContext->sync.videoFrameAvailableCond);
402	ConditionWake(&threadContext->sync.videoFrameRequiredCond);
403	ConditionDeinit(&threadContext->sync.videoFrameRequiredCond);
404
405	ConditionWake(&threadContext->sync.audioRequiredCond);
406	ConditionDeinit(&threadContext->sync.audioRequiredCond);
407	MutexDeinit(&threadContext->sync.audioBufferMutex);
408
409	int i;
410	for (i = 0; i < threadContext->rewindBufferCapacity; ++i) {
411		if (threadContext->rewindBuffer[i]) {
412			GBADeallocateState(threadContext->rewindBuffer[i]);
413		}
414	}
415	free(threadContext->rewindBuffer);
416
417	if (threadContext->rom) {
418		threadContext->rom->close(threadContext->rom);
419		threadContext->rom = 0;
420	}
421
422	if (threadContext->save) {
423		threadContext->save->close(threadContext->save);
424		threadContext->save = 0;
425	}
426
427	if (threadContext->bios) {
428		threadContext->bios->close(threadContext->bios);
429		threadContext->bios = 0;
430	}
431
432	if (threadContext->patch) {
433		threadContext->patch->close(threadContext->patch);
434		threadContext->patch = 0;
435	}
436
437	if (threadContext->gameDir) {
438		if (threadContext->stateDir == threadContext->gameDir) {
439			threadContext->stateDir = 0;
440		}
441		threadContext->gameDir->close(threadContext->gameDir);
442		threadContext->gameDir = 0;
443	}
444
445	if (threadContext->stateDir) {
446		threadContext->stateDir->close(threadContext->stateDir);
447		threadContext->stateDir = 0;
448	}
449}
450
451bool GBAThreadIsActive(struct GBAThread* threadContext) {
452	return threadContext->state >= THREAD_RUNNING && threadContext->state < THREAD_EXITING;
453}
454
455void GBAThreadInterrupt(struct GBAThread* threadContext) {
456	MutexLock(&threadContext->stateMutex);
457	++threadContext->interruptDepth;
458	if (threadContext->interruptDepth > 1 || !GBAThreadIsActive(threadContext)) {
459		MutexUnlock(&threadContext->stateMutex);
460		return;
461	}
462	threadContext->savedState = threadContext->state;
463	_waitOnInterrupt(threadContext);
464	threadContext->state = THREAD_INTERRUPTING;
465	if (threadContext->debugger && threadContext->debugger->state == DEBUGGER_RUNNING) {
466		threadContext->debugger->state = DEBUGGER_EXITING;
467	}
468	ConditionWake(&threadContext->stateCond);
469	_waitUntilNotState(threadContext, THREAD_INTERRUPTING);
470	MutexUnlock(&threadContext->stateMutex);
471}
472
473void GBAThreadContinue(struct GBAThread* threadContext) {
474	MutexLock(&threadContext->stateMutex);
475	--threadContext->interruptDepth;
476	if (threadContext->interruptDepth < 1 && GBAThreadIsActive(threadContext)) {
477		threadContext->state = threadContext->savedState;
478		ConditionWake(&threadContext->stateCond);
479	}
480	MutexUnlock(&threadContext->stateMutex);
481}
482
483void GBAThreadPause(struct GBAThread* threadContext) {
484	bool frameOn = true;
485	MutexLock(&threadContext->stateMutex);
486	_waitOnInterrupt(threadContext);
487	if (threadContext->state == THREAD_RUNNING) {
488		_pauseThread(threadContext, false);
489		frameOn = false;
490	}
491	MutexUnlock(&threadContext->stateMutex);
492
493	_changeVideoSync(&threadContext->sync, frameOn);
494}
495
496void GBAThreadUnpause(struct GBAThread* threadContext) {
497	MutexLock(&threadContext->stateMutex);
498	_waitOnInterrupt(threadContext);
499	if (threadContext->state == THREAD_PAUSED || threadContext->state == THREAD_PAUSING) {
500		threadContext->state = THREAD_RUNNING;
501		ConditionWake(&threadContext->stateCond);
502	}
503	MutexUnlock(&threadContext->stateMutex);
504
505	_changeVideoSync(&threadContext->sync, true);
506}
507
508bool GBAThreadIsPaused(struct GBAThread* threadContext) {
509	bool isPaused;
510	MutexLock(&threadContext->stateMutex);
511	_waitOnInterrupt(threadContext);
512	isPaused = threadContext->state == THREAD_PAUSED;
513	MutexUnlock(&threadContext->stateMutex);
514	return isPaused;
515}
516
517void GBAThreadTogglePause(struct GBAThread* threadContext) {
518	bool frameOn = true;
519	MutexLock(&threadContext->stateMutex);
520	_waitOnInterrupt(threadContext);
521	if (threadContext->state == THREAD_PAUSED || threadContext->state == THREAD_PAUSING) {
522		threadContext->state = THREAD_RUNNING;
523		ConditionWake(&threadContext->stateCond);
524	} else if (threadContext->state == THREAD_RUNNING) {
525		_pauseThread(threadContext, false);
526		frameOn = false;
527	}
528	MutexUnlock(&threadContext->stateMutex);
529
530	_changeVideoSync(&threadContext->sync, frameOn);
531}
532
533void GBAThreadPauseFromThread(struct GBAThread* threadContext) {
534	bool frameOn = true;
535	MutexLock(&threadContext->stateMutex);
536	_waitOnInterrupt(threadContext);
537	if (threadContext->state == THREAD_RUNNING) {
538		_pauseThread(threadContext, true);
539		frameOn = false;
540	}
541	MutexUnlock(&threadContext->stateMutex);
542
543	_changeVideoSync(&threadContext->sync, frameOn);
544}
545
546#ifdef USE_PTHREADS
547struct GBAThread* GBAThreadGetContext(void) {
548	pthread_once(&_contextOnce, _createTLS);
549	return pthread_getspecific(_contextKey);
550}
551#elif _WIN32
552struct GBAThread* GBAThreadGetContext(void) {
553	InitOnceExecuteOnce(&_contextOnce, _createTLS, NULL, 0);
554	return TlsGetValue(_contextKey);
555}
556#endif
557
558#ifdef USE_PNG
559void GBAThreadTakeScreenshot(struct GBAThread* threadContext) {
560	unsigned stride;
561	void* pixels = 0;
562	struct VFile* vf = VDirOptionalOpenIncrementFile(threadContext->stateDir, threadContext->gba->activeFile, "screenshot", "-", ".png", O_CREAT | O_TRUNC | O_WRONLY);
563	threadContext->gba->video.renderer->getPixels(threadContext->gba->video.renderer, &stride, &pixels);
564	png_structp png = PNGWriteOpen(vf);
565	png_infop info = PNGWriteHeader(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS);
566	PNGWritePixels(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS, stride, pixels);
567	PNGWriteClose(png, info);
568	vf->close(vf);
569}
570#endif
571
572#else
573struct GBAThread* GBAThreadGetContext(void) {
574	return 0;
575}
576#endif
577
578void GBASyncPostFrame(struct GBASync* sync) {
579	if (!sync) {
580		return;
581	}
582
583	MutexLock(&sync->videoFrameMutex);
584	++sync->videoFramePending;
585	--sync->videoFrameSkip;
586	if (sync->videoFrameSkip < 0) {
587		do {
588			ConditionWake(&sync->videoFrameAvailableCond);
589			if (sync->videoFrameWait) {
590				ConditionWait(&sync->videoFrameRequiredCond, &sync->videoFrameMutex);
591			}
592		} while (sync->videoFrameWait && sync->videoFramePending);
593	}
594	MutexUnlock(&sync->videoFrameMutex);
595
596	struct GBAThread* thread = GBAThreadGetContext();
597	if (!thread) {
598		return;
599	}
600
601	if (thread->rewindBuffer) {
602		--thread->rewindBufferNext;
603		if (thread->rewindBufferNext <= 0) {
604			thread->rewindBufferNext = thread->rewindBufferInterval;
605			GBARecordFrame(thread);
606		}
607	}
608	if (thread->stream) {
609		thread->stream->postVideoFrame(thread->stream, thread->renderer);
610	}
611	if (thread->frameCallback) {
612		thread->frameCallback(thread);
613	}
614}
615
616bool GBASyncWaitFrameStart(struct GBASync* sync, int frameskip) {
617	if (!sync) {
618		return true;
619	}
620
621	MutexLock(&sync->videoFrameMutex);
622	ConditionWake(&sync->videoFrameRequiredCond);
623	if (!sync->videoFrameOn && !sync->videoFramePending) {
624		return false;
625	}
626	if (sync->videoFrameOn) {
627		ConditionWait(&sync->videoFrameAvailableCond, &sync->videoFrameMutex);
628	}
629	sync->videoFramePending = 0;
630	sync->videoFrameSkip = frameskip;
631	return true;
632}
633
634void GBASyncWaitFrameEnd(struct GBASync* sync) {
635	if (!sync) {
636		return;
637	}
638
639	MutexUnlock(&sync->videoFrameMutex);
640}
641
642bool GBASyncDrawingFrame(struct GBASync* sync) {
643	if (!sync) {
644		return true;
645	}
646
647	return sync->videoFrameSkip <= 0;
648}
649
650void GBASyncSuspendDrawing(struct GBASync* sync) {
651	if (!sync) {
652		return;
653	}
654
655	_changeVideoSync(sync, false);
656}
657
658void GBASyncResumeDrawing(struct GBASync* sync) {
659	if (!sync) {
660		return;
661	}
662
663	_changeVideoSync(sync, true);
664}
665
666void GBASyncProduceAudio(struct GBASync* sync, bool wait) {
667	if (!sync) {
668		return;
669	}
670
671	if (sync->audioWait && wait) {
672		// TODO loop properly in event of spurious wakeups
673		ConditionWait(&sync->audioRequiredCond, &sync->audioBufferMutex);
674	}
675	MutexUnlock(&sync->audioBufferMutex);
676}
677
678void GBASyncLockAudio(struct GBASync* sync) {
679	if (!sync) {
680		return;
681	}
682
683	MutexLock(&sync->audioBufferMutex);
684}
685
686void GBASyncUnlockAudio(struct GBASync* sync) {
687	if (!sync) {
688		return;
689	}
690
691	MutexUnlock(&sync->audioBufferMutex);
692}
693
694void GBASyncConsumeAudio(struct GBASync* sync) {
695	if (!sync) {
696		return;
697	}
698
699	ConditionWake(&sync->audioRequiredCond);
700	MutexUnlock(&sync->audioBufferMutex);
701}