port: revert multithreaded audio experiments

until I can figure out how to fix all the funny concurrency issues that cropped up

Makefile.port

@@ -150,7 +150,7 @@ B_DIR := build/$(ROMID)-port
 G_DIR := src/generated/$(ROMID)
 
 ifneq (,$(findstring windows,$(TARGET_PLATFORM)))
-  TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I) -pthread
+  TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I)
   TARGET_LDFLAGS := $(shell pkg-config sdl2 --libs) -lz -lopengl32 -ldbghelp
   # on windows/mingw we need this to be built with a 32-bit compiler so it finds the correct libs
   TOOLCHAIN ?= i686-w64-mingw32-
@@ -161,7 +161,7 @@ ifneq (,$(findstring windows,$(TARGET_PLATFORM)))
     TARGET_LDFLAGS += -lstdc++
   endif
 else # assume *nix
-  TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I) -pthread
+  TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I)
   TARGET_LDFLAGS := $(shell pkg-config sdl2 --libs) -lGL -lz -ldl
   ifneq (,$(findstring arm,$(TARGET_PLATFORM))$(findstring aarch,$(TARGET_PLATFORM)))
     # linux on arm or aarch64

port/fast3d/gfx_sdl2.cpp

@@ -261,7 +261,7 @@ static inline void sync_framerate_with_timer(void) {
     // We want to exit a bit early, so we can busy-wait the rest to never miss the deadline
     left -= 15000UL;
     if (left > 0) {
-        sysFrameLimiterSleep(left);
+        sysSleep(left);
     }
 
     do {

port/include/audio.h

@@ -6,6 +6,7 @@
 s32 audioInit(void);
 s32 audioGetBytesBuffered(void);
 s32 audioGetSamplesBuffered(void);
-void audioSubmitBuffer(const s16 *buf, u32 size);
+void audioSetNextBuffer(const s16 *buf, u32 len);
+void audioEndFrame(void);
 
 #endif

port/include/system.h

@@ -35,11 +35,7 @@ void *sysMemZeroAlloc(const u32 size);
 void sysMemFree(void *ptr);
 
 // hns is specified in 100ns units
-// do not use sysFrameLimiterSleep on any thread other than the main one
-void sysFrameLimiterSleep(const s64 hns);
-
-// us is specified in microseconds
-void sysSleep(const s64 us);
+void sysSleep(const s64 hns);
 
 // yield CPU if supported (e.g. during a busy loop)
 void sysCpuRelax(void);

port/include/thread.h

@@ -1,27 +0,0 @@
-#ifndef _IN_THREAD_H
-#define _IN_THREAD_H
-
-#include <PR/ultratypes.h>
-#include "platform.h"
-
-// TODO: backends
-#ifndef PLATFORM_USE_PTHREAD
-#error "No available thread backend."
-#endif
-
-#include <pthread.h>
-
-#define SYSMUTEX_STATIC_INIT PTHREAD_MUTEX_INITIALIZER
-
-typedef pthread_t systhread;
-typedef pthread_mutex_t sysmutex;
-
-typedef void *(*systhreadfn)(void *);
-
-s32 sysThreadCreate(systhread *thread, systhreadfn func, void *arg);
-s32 sysThreadJoin(systhread *thread, void **result);
-
-void sysMutexLock(sysmutex *mtx);
-void sysMutexUnlock(sysmutex *mtx);
-
-#endif // _IN_THREAD_H

port/src/audio.c

@@ -7,13 +7,12 @@
 #include "system.h"
 
 static SDL_AudioDeviceID dev;
+static const s16 *nextBuf;
+static u32 nextSize = 0;
 
 static s32 bufferSize = 512;
 static s32 queueLimit = 8192;
 
-static f32 offsetFrames = 0.5f;
-static u32 offsetBytes;
-
 s32 audioInit(void)
 {
 	if (SDL_InitSubSystem(SDL_INIT_AUDIO) != 0) {
@@ -29,8 +28,7 @@ s32 audioInit(void)
 	want.samples = bufferSize;
 	want.callback = NULL;
 
-	const f32 spf = (f32)want.freq / (PAL ? 50.f : 60.f);
-	offsetBytes = offsetFrames * spf * (f32)sizeof(int16_t);
+	nextBuf = NULL;
 
 	dev = SDL_OpenAudioDevice(NULL, 0, &want, &have, 0);
 	if (dev == 0) {
@@ -45,39 +43,33 @@ s32 audioInit(void)
 
 s32 audioGetBytesBuffered(void)
 {
-	u32 count = SDL_GetQueuedAudioSize(dev);
-
-	// pd's audio code decides how many samples of audio to produce based on the amount of audio
-	// currently buffered, so we adjust the reported count to be some number of frames in the future
-	// to counteract lag; idea shamelessly stolen from mm recomp
-	if (offsetBytes) {
-		if (count > offsetBytes) {
-			count -= offsetBytes;
-		} else {
-			count = 0;
-		}
-	}
-
-	return count;
+	return SDL_GetQueuedAudioSize(dev);
 }
 
 s32 audioGetSamplesBuffered(void)
 {
-	return audioGetBytesBuffered() / (2 * sizeof(s16));
+	return audioGetBytesBuffered() / 4;
 }
 
-void audioSubmitBuffer(const s16 *buf, u32 size)
+void audioSetNextBuffer(const s16 *buf, u32 len)
 {
-	if (buf && size) {
+	nextBuf = buf;
+	nextSize = len;
+}
+
+void audioEndFrame(void)
+{
+	if (nextBuf && nextSize) {
 		if (audioGetSamplesBuffered() < queueLimit) {
-			SDL_QueueAudio(dev, buf, size);
+			SDL_QueueAudio(dev, nextBuf, nextSize);
 		}
+		nextBuf = NULL;
+		nextSize = 0;
 	}
 }
 
 PD_CONSTRUCTOR static void audioConfigInit(void)
 {
 	configRegisterInt("Audio.BufferSize", &bufferSize, 0, 1 * 1024 * 1024);
-	configRegisterFloat("Audio.OffsetFrames", &offsetFrames, 0.f, 5.f);
 	configRegisterInt("Audio.QueueLimit", &queueLimit, 0, 1 * 1024 * 1024);
 }

port/src/libultra.c

@@ -166,7 +166,7 @@ u32 osAiGetLength(void)
 
 s32 osAiSetNextBuffer(void *bufPtr, u32 size)
 {
-	audioSubmitBuffer(bufPtr, size);
+	audioSetNextBuffer(bufPtr, size);
 	return 0;
 }
 

port/src/pdmain.c

@@ -501,7 +501,7 @@ void mainLoop(void)
 				schedEndFrame(&g_Sched);
 			}
 			if (g_TickExtraSleep) {
-				sysFrameLimiterSleep(EXTRA_SLEEP_TIME);
+				sysSleep(EXTRA_SLEEP_TIME);
 			}
 		}
 

port/src/pdsched.c

@@ -242,6 +242,18 @@ void schedStartFrame(OSSched *sc)
 	videoStartFrame();
 }
 
+void schedAudioFrame(OSSched *sc)
+{
+	s32 i;
+
+	if (!g_SndDisabled) {
+		for (i = 0; i < g_Vars.diffframe60; i++) {
+			amgrFrame();
+			audioEndFrame();
+		}
+	}
+}
+
 /**
  * Handle a retrace (vsync) event.
  *
@@ -260,6 +272,18 @@ void schedEndFrame(OSSched *sc)
 {
 	sc->frameCount++;
 
+#if PAL
+	if (!g_Resetting && (sc->frameCount & 1)) {
+		// osStopTimer(&g_SchedRspTimer);
+		// osSetTimer(&g_SchedRspTimer, 280000, 0, amgrGetFrameMesgQueue(), &g_SchedRspMsg);
+	}
+#else
+	if (!g_Resetting && ((sc->frameCount & 1) || IS4MB())) {
+		// osStopTimer(&g_SchedRspTimer);
+		// osSetTimer(&g_SchedRspTimer, 280000, 0, amgrGetFrameMesgQueue(), &g_SchedRspMsg);
+	}
+#endif
+
 	if (!g_Resetting) {
 		viHandleRetrace();
 	}
@@ -271,6 +295,7 @@ void schedEndFrame(OSSched *sc)
 	joy00014238();
 
 	sndHandleRetrace();
+	schedAudioFrame(sc);
 	schedRenderCrashPeriodically(sc->frameCount);
 	videoEndFrame();
 

port/src/system.c

@@ -9,7 +9,6 @@
 #include <strings.h>
 #include <time.h>
 #include <sys/time.h>
-#include <unistd.h>
 #include <SDL.h>
 #include <PR/ultratypes.h>
 #include "platform.h"
@@ -33,6 +32,8 @@ __attribute__((dllexport)) u32 AmdPowerXpressRequestHighPerformance = 1;
 
 #else
 
+#include <unistd.h>
+
 // figure out how to yield
 #if defined(PLATFORM_X86) || defined(PLATFORM_X86_64)
 // this should work even if the code is not built with SSE enabled, at least on gcc and clang,
@@ -292,7 +293,7 @@ void sysMemFree(void *ptr)
 	free(ptr);
 }
 
-void sysFrameLimiterSleep(const s64 hns)
+void sysSleep(const s64 hns)
 {
 #ifdef PLATFORM_WIN32
 	static LARGE_INTEGER li;
@@ -305,12 +306,6 @@ void sysFrameLimiterSleep(const s64 hns)
 #endif
 }
 
-void sysSleep(const s64 us)
-{
-	const struct timespec spec = { 0, us * 1000 };
-	nanosleep(&spec, NULL);
-}
-
 void sysCpuRelax(void)
 {
 	DO_YIELD();

port/src/thread.c

@@ -1,27 +0,0 @@
-#include "thread.h"
-
-#ifndef PLATFORM_USE_PTHREAD
-#error "No available thread backend."
-#endif
-
-#include <pthread.h>
-
-s32 sysThreadCreate(systhread *thread, systhreadfn func, void *arg)
-{
-	return pthread_create(thread, NULL, func, arg);
-}
-
-s32 sysThreadJoin(systhread *thread, void **result)
-{
-	return pthread_join(*thread, result);
-}
-
-void sysMutexLock(sysmutex *mtx)
-{
-	pthread_mutex_lock(mtx);
-}
-
-void sysMutexUnlock(sysmutex *mtx)
-{
-	pthread_mutex_unlock(mtx);
-}

src/game/chraicommands.c

@@ -9840,14 +9840,20 @@ bool aiIfMusicEventQueueIsEmpty(void)
 {
 	f32 value = (u64)osGetCount() * 64 / 3000;
 
+#ifdef PLATFORM_N64 // will hang forever until the audio thread wakes it up
 	if (g_MusicEventQueueLength) {
-#ifndef PLATFORM_N64
-		musicTickEvents();
+#else	// HACK: will wait 1 frame and get on with it
+	static bool waited = false;
+	if (g_MusicEventQueueLength && !waited) {
+		waited = true;
 #endif
 		g_Vars.aioffset += 4;
 	} else {
 		u8 *cmd = g_Vars.ailist + g_Vars.aioffset;
 		g_Vars.aioffset = chraiGoToLabel(g_Vars.ailist, g_Vars.aioffset, cmd[3]);
+#ifndef PLATFORM_N64
+		waited = false;
+#endif
 	}
 
 	return false;

src/game/timing.c

@@ -47,7 +47,7 @@ void frametimeCalculate(void)
 
 #ifndef PLATFORM_N64
 		if (g_TickExtraSleep) {
-			sysFrameLimiterSleep(EXTRA_SLEEP_TIME);
+			sysSleep(EXTRA_SLEEP_TIME);
 		}
 #endif
 	} while (g_Vars.mininc60 && diffframe60 < g_Vars.mininc60);

src/include/lib/audiomgr.h

@@ -17,11 +17,7 @@ OSMesgQueue *amgrGetFrameMesgQueue(void);
 void amgrStopThread(void);
 
 #ifndef PLATFORM_N64
-void amgrLock(void);
-void amgrUnlock(void);
-#else
-#define amgrLock() do {} while(0)
-#define amgrUnlock() do {} while(0)
+void amgrFrame(void);
 #endif
 
 #endif

src/include/platform.h

@@ -34,9 +34,6 @@
 	#error "64-bit platforms are currently not supported."
 #endif
 
-// threading backend
-#define PLATFORM_USE_PTHREAD 1
-
 // detect endianness
 #if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
 	#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

src/lib/audiomgr.c

@@ -10,13 +10,6 @@
 #include "lib/libc/ll.h"
 #include "data.h"
 #include "types.h"
-#ifndef PLATFORM_N64
-#include "lib/audiomgr.h"
-#include "thread.h"
-#include "audio.h"
-#include "system.h"
-#define AMGR_THREAD_SLEEP_US 2000
-#endif
 
 u32 var80091560;
 u32 var80091564;
@@ -50,14 +43,6 @@ void *g_AudioSp;
 u32 var8005cf90 = 0x00000000;
 u8 var8005cf94 = 1;
 
-#ifndef PLATFORM_N64
-systhread g_AmgrThread;
-sysmutex g_AmgrMutex = SYSMUTEX_STATIC_INIT;
-u32 g_AmgrFrame;
-u32 g_AmgrFrameTarget;
-void *amgrThread(void *arg);
-#endif
-
 void amgrHandleDoneMsg(AudioInfo *info);
 void amgrHandleFrameMsg(AudioInfo *info, AudioInfo *previnfo);
 void amgrMain(void *arg);
@@ -170,9 +155,6 @@ void amgrStartThread(void)
 {
 	osStartThread(&g_AudioManager.thread);
 	g_AudioIsThreadRunning = true;
-#ifndef PLATFORM_N64
-	sysThreadCreate(&g_AmgrThread, &amgrThread, NULL);
-#endif
 }
 
 OSMesgQueue *amgrGetFrameMesgQueue(void)
@@ -189,12 +171,6 @@ void amgrStopThread(void)
 {
 	if (g_AudioIsThreadRunning) {
 		osStopThread(&g_AudioManager.thread);
-#ifndef PLATFORM_N64
-		amgrLock();
-		g_AudioIsThreadRunning = false;
-		amgrUnlock();
-		sysThreadJoin(&g_AmgrThread, NULL);
-#endif
 	}
 }
 
@@ -345,14 +321,11 @@ void amgrHandleDoneMsg(AudioInfo *info)
 }
 
 #ifndef PLATFORM_N64
-
 void amgrFrame(void)
 {
 	static AudioInfo *previnfo = NULL;
 	static s32 count = 0;
 
-	amgrLock();
-
 	var80091588 = osGetTime();
 
 	AudioInfo *info = g_AudioManager.audioInfo[g_AdmaCurFrame % 3];
@@ -390,8 +363,6 @@ void amgrFrame(void)
 
 	count++;
 
-	amgrUnlock();
-
 	var80091590 = osGetTime();
 	var80091570 = var80091590 - var80091588;
 
@@ -406,41 +377,4 @@ void amgrFrame(void)
 		var80091568 = var80091590 - var80091588;
 	}
 }
-
-void amgrLock(void)
-{
-	sysMutexLock(&g_AmgrMutex);
-}
-
-void amgrUnlock(void)
-{
-	sysMutexUnlock(&g_AmgrMutex);
-}
-
-void *amgrThread(void *arg)
-{
-	const f64 frametime = 1000000.0 / (PAL ? 50.0 : 60.0);
-	bool running = g_AudioIsThreadRunning;
-	f64 nexttick = sysGetMicroseconds();
-	f64 tick;
-
-	while (running) {
-		tick = sysGetMicroseconds() + 0.01;
-
-		while (nexttick < tick) {
-			amgrFrame();
-			g_AmgrFrame++;
-			nexttick += frametime;
-		}
-
-		sysSleep(AMGR_THREAD_SLEEP_US);
-
-		amgrLock();
-		running = g_AudioIsThreadRunning;
-		amgrUnlock();
-	}
-
-	return NULL;
-}
-
 #endif