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Remove busy loops #1367

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14 changes: 10 additions & 4 deletions Source/AliveLibAE/Psx.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
#include "PsxRender.hpp"
#include "Renderer/IRenderer.hpp"
#include <gmock/gmock.h>
#include <thread>

void Psx_ForceLink()
{ }
Expand Down Expand Up @@ -891,16 +892,21 @@ EXPORT s32 CC PSX_VSync_4F6170(s32 mode)
s32 frameTimeInMilliseconds = currentTime - sVSyncLastMillisecond_BD0F2C;
if (mode > 0 && frameTimeInMilliseconds < 1000 * mode / 60)
{
s32 timeSinceLastFrame = 0;
sVSync_Unused_578325 = 1;

do
auto current = SYS_GetTime();
const auto max_time = current + std::chrono::milliseconds(1000 * mode / 60);

while (SsSeqCalledTbyT_4FDC80_sleep_until_due_time_if_before_max_time(current, max_time))
{
timeSinceLastFrame = SYS_GetTicks() - sVSyncLastMillisecond_BD0F2C;
SsSeqCalledTbyT_4FDC80();
current = SYS_GetTime();
}
while (timeSinceLastFrame < 1000 * mode / 60);

if (current < max_time)
{
std::this_thread::sleep_until(max_time);
}
frameTimeInMilliseconds = 1000 * mode / 60;
}

Expand Down
39 changes: 36 additions & 3 deletions Source/AliveLibAE/Sound/PsxSpuApi.cpp
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Expand Up @@ -9,6 +9,7 @@
#include "PathData.hpp" // SoundBlockInfo, SeqPathDataRecord
#include "../AliveLibAE/Io.hpp"
#include <assert.h>
#include <thread>

struct VagAtr final
{
Expand Down Expand Up @@ -1346,19 +1347,51 @@ EXPORT void CC SsSetTickMode_4FDC20(s32)
// Stub
}

// TODO: Removed 4FDC30
EXPORT bool CC SsSeqCalledTbyT_4FDC80_sleep_until_due_time_if_before_max_time(SYS_time_point_t current_time, SYS_time_point_t max_time)
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@MrSapps MrSapps Dec 5, 2021

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_4FDC80 needs to be at the end of the function as exported function names are parsed at runtime for installing hooks into the game when running as a DLL. This name is super verbose too, I would have just left it as SsSeqCalledTbyT_4FDC80 tbh since the waiting/sleeping is an implementation detail.

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@ilelann ilelann Dec 5, 2021

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I meant to avoid breaking existing SsSeqCalledTbyT_4FDC80 ABI with "max_time" new argument.
(because I understood that number-suffixed functions are meant to be interchangeable with original binaries)
Unless I miss something, I thus can simplify the name but not use the original one.

{
if (!gSpuVars->sbDisableSeqs())
{
const auto lastTime = gSpuVars->sLastTime();
if (lastTime == 0xFFFFFFFF)
{
return true;
}
else
{
const auto nextDueTime = lastTime + 30;

if ((s32) (SYS_AsU32Ms(max_time) - nextDueTime) < 0)
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use static_cast instead of a C cast

{
// we won't make it in time, skip
return false;
}

const auto timeToWait = (s32) (nextDueTime - SYS_AsU32Ms(current_time));
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use static_cast instead of a C cast

if (timeToWait <= 0)
{
// we're late or right on time, hurry!
return true;
}

std::this_thread::sleep_for(std::chrono::milliseconds{timeToWait});
return true;
}
}
return false;
}

// TODO: Removed 4FDC30
EXPORT void CC SsSeqCalledTbyT_4FDC80()
{
if (!gSpuVars->sbDisableSeqs())
{
const u32 currentTime = SYS_GetTicks();
gSpuVars->sMidiTime() = currentTime;
// First time or 30 passed?
if (gSpuVars->sLastTime() == 0xFFFFFFFF || (s32)(currentTime - gSpuVars->sLastTime()) >= 30)
auto& lastTime = gSpuVars->sLastTime();
if (lastTime == 0xFFFFFFFF || (s32) (currentTime - lastTime) >= 30)
{
gSpuVars->sLastTime() = currentTime;
lastTime = currentTime;
for (s32 i = 0; i < kNumChannels; i++)
{
if (gSpuVars->sMidiSeqSongs(i).field_0_seq_data)
Expand Down
7 changes: 7 additions & 0 deletions Source/AliveLibAE/Sound/PsxSpuApi.hpp
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Expand Up @@ -3,6 +3,7 @@
#include "../AliveLibCommon/FunctionFwd.hpp"
#include "Sound/Sound.hpp"
#include "Io.hpp"
#include "Sys_common.hpp"

struct ProgAtr final
{
Expand Down Expand Up @@ -239,6 +240,12 @@ EXPORT void CC VSyncCallback_4F8C40(TVSyncCallBackFn callBack);
EXPORT void CC SND_CallBack_4020A4(); // TODO: Naming??
EXPORT void CC SsSeqCalledTbyT_4FDC80();

// returns
// true, after having slept for the correct duration, if SsSeqCalledTbyT_4FDC80 must be called
// false if time to wait would have gone over max_time
// Note that this does *not* call SsSeqCalledTbyT_4FDC80
EXPORT bool CC SsSeqCalledTbyT_4FDC80_sleep_until_due_time_if_before_max_time(SYS_time_point_t current_time, SYS_time_point_t max_time);

// Most likely PC specific extensions that have been inlined
void SsExt_CloseAllVabs();

Expand Down
16 changes: 16 additions & 0 deletions Source/AliveLibAE/Sound/SDLSoundSystem.cpp
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Expand Up @@ -100,6 +100,11 @@ HRESULT SDLSoundSystem::Release()

// Stop audio rendering thread
mRenderAudioThreadQuit = true;
{
std::lock_guard g{mAudioRingBufferMutex};
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@MrSapps MrSapps Dec 5, 2021

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instead of 'g' can we at least called it 'lock' or something

mAudioRingBufferConditionVariable.notify_one();
}

if (mRenderAudioThread && mRenderAudioThread->joinable())
{
mRenderAudioThread->join();
Expand Down Expand Up @@ -139,6 +144,11 @@ void SDLSoundSystem::AudioCallBack(Uint8* stream, s32 len)
{
LOG_ERROR("Ring buffer read failure!");
}

{
std::lock_guard g{mAudioRingBufferMutex};
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ditto for naming

mAudioRingBufferConditionVariable.notify_one();
}
}


Expand All @@ -159,6 +169,12 @@ void SDLSoundSystem::RenderAudioThread()
LOG_ERROR("Ring buffer write failed");
}
}
else
{
std::unique_lock g{mAudioRingBufferMutex};
mAudioRingBufferConditionVariable.wait(g, [&]
{ return mRenderAudioThreadQuit || mAudioRingBuffer.getAvailableWrite() > 0; });
}
}
LOG_INFO("Quit");
}
Expand Down
7 changes: 7 additions & 0 deletions Source/AliveLibAE/Sound/SDLSoundSystem.hpp
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Expand Up @@ -3,6 +3,8 @@
#include "Sound.hpp"
#include "SoundSDL.hpp"
#include <thread>
#include <condition_variable>
#include <mutex>

#define CI_DISABLE_ASSERTS
#include <cinder/audio/dsp/RingBuffer.h>
Expand Down Expand Up @@ -53,6 +55,11 @@ class SDLSoundSystem final
std::vector<StereoSample_S16> mTempSoundBuffer;
std::vector<StereoSample_S16> mNoReverbBuffer;
cinder::audio::dsp::RingBufferT<StereoSample_S16> mAudioRingBuffer;

// to avoid busy loop
std::mutex mAudioRingBufferMutex;
std::condition_variable mAudioRingBufferConditionVariable;

std::atomic_bool mRenderAudioThreadQuit{false};
std::unique_ptr<std::thread> mRenderAudioThread;

Expand Down
9 changes: 5 additions & 4 deletions Source/AliveLibAO/Movie.cpp
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Expand Up @@ -444,7 +444,7 @@ void Movie::VUpdate_489EA0()
Bitmap tmpBmp = {};

// Till EOF decoding loop
const auto movieStartTimeStamp = SYS_GetTicks();
const auto movieStartTimeStamp = SYS_GetTime();
while (psxStr.DecodeAudioAndVideo())
{
fmv_num_read_frames++;
Expand Down Expand Up @@ -492,11 +492,12 @@ void Movie::VUpdate_489EA0()

Render_Str_Frame(tmpBmp);

const int maxAudioSyncTimeWait = 1000 * fmv_num_read_frames / kFmvFrameRate - 200;

while ((signed int) (SYS_GetTicks() - movieStartTimeStamp) <= maxAudioSyncTimeWait)
const auto maxAudioSyncTimeWait = std::chrono::milliseconds{1000 * fmv_num_read_frames / kFmvFrameRate - 200};
const auto timeToWait = maxAudioSyncTimeWait - (SYS_GetTime() - movieStartTimeStamp);
if (timeToWait.count() > 0)
{
// Wait for the amount of time the frame would take to display at the given framerate
std::this_thread::sleep_for(timeToWait);
}

SYS_EventsPump_44FF90();
Expand Down
17 changes: 10 additions & 7 deletions Source/AliveLibCommon/Sys_common.cpp
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Expand Up @@ -13,16 +13,19 @@
abort();
}

SYS_time_point_t SYS_GetTime()
{
return std::chrono::steady_clock::now();
}

u32 SYS_AsU32Ms(SYS_time_point_t t)
{
return (u32) std::chrono::duration_cast<std::chrono::milliseconds>(t.time_since_epoch()).count();
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static_cast instead of C cast

}

u32 SYS_GetTicks()
{
#if USE_SDL2
// Using this instead of SDL_GetTicks resolves a weird x64 issue on windows where
// the tick returned is a lot faster on some machines.
return static_cast<u32>(SDL_GetPerformanceCounter() / (SDL_GetPerformanceFrequency() / 1000));
#else
return timeGetTime();
#endif
return SYS_AsU32Ms(SYS_GetTime());
}

MessageBoxButton CC Sys_MessageBox(TWindowHandleType windowHandle, const char_type* message, const char_type* title, MessageBoxType type)
Expand Down
4 changes: 4 additions & 0 deletions Source/AliveLibCommon/Sys_common.hpp
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Expand Up @@ -2,6 +2,7 @@

#include "../AliveLibCommon/FunctionFwd.hpp"
#include "relive_config.h"
#include <chrono>

#if _WIN32
using TWindowProcFilter = LRESULT(CC*)(HWND, UINT, WPARAM, LPARAM);
Expand Down Expand Up @@ -77,4 +78,7 @@ inline void Alive_Show_ErrorMsg(const char_type* msg)

[[noreturn]] void ALIVE_FATAL(const char_type* errMsg);

using SYS_time_point_t = std::chrono::steady_clock::time_point;
SYS_time_point_t SYS_GetTime();
u32 SYS_AsU32Ms(SYS_time_point_t);
u32 SYS_GetTicks();