From 177d697a15fa27e35b4803e02b0dbc97a2862677 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Sun, 5 Jul 2020 10:37:44 +0200
Subject: [PATCH] Revert "Remove the I/O on Thread option - treat it as always
 on."

This reverts commit 9c40381db090285aa7848bfee93dca6c4a220b62.
---
 Core/Config.cpp           |  1 +
 Core/Config.h             |  1 +
 Core/HLE/sceIo.cpp        | 18 ++++++++++++------
 UI/GameSettingsScreen.cpp |  2 ++
 4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/Core/Config.cpp b/Core/Config.cpp
index 8af00b96ac3e..df3bf415dc78 100644
--- a/Core/Config.cpp
+++ b/Core/Config.cpp
@@ -504,6 +504,7 @@ static bool DefaultSasThread() {
 static ConfigSetting cpuSettings[] = {
 	ReportedConfigSetting("CPUCore", &g_Config.iCpuCore, &DefaultCpuCore, true, true),
 	ReportedConfigSetting("SeparateSASThread", &g_Config.bSeparateSASThread, &DefaultSasThread, true, true),
+	ReportedConfigSetting("SeparateIOThread", &g_Config.bSeparateIOThread, true, true, true),
 	ReportedConfigSetting("IOTimingMethod", &g_Config.iIOTimingMethod, IOTIMING_FAST, true, true),
 	ConfigSetting("FastMemoryAccess", &g_Config.bFastMemory, true, true, true),
 	ReportedConfigSetting("FuncReplacements", &g_Config.bFuncReplacements, true, true, true),
diff --git a/Core/Config.h b/Core/Config.h
index 084eacc942b8..2e5cea51c91a 100644
--- a/Core/Config.h
+++ b/Core/Config.h
@@ -108,6 +108,7 @@ struct Config {
 	uint32_t uJitDisableFlags;
 
 	bool bSeparateSASThread;
+	bool bSeparateIOThread;
 	int iIOTimingMethod;
 	int iLockedCPUSpeed;
 	bool bAutoSaveSymbolMap;
diff --git a/Core/HLE/sceIo.cpp b/Core/HLE/sceIo.cpp
index 9f3cf81f7837..7865d4cea530 100644
--- a/Core/HLE/sceIo.cpp
+++ b/Core/HLE/sceIo.cpp
@@ -129,7 +129,7 @@ static MemStickFatState lastMemStickFatState;
 
 static AsyncIOManager ioManager;
 static bool ioManagerThreadEnabled = false;
-static std::thread ioManagerThread;
+static std::thread *ioManagerThread;
 
 // TODO: Is it better to just put all on the thread?
 // Let's try. (was 256)
@@ -649,10 +649,12 @@ void __IoInit() {
 
 	memset(fds, 0, sizeof(fds));
 
-	ioManagerThreadEnabled = true;
+	ioManagerThreadEnabled = g_Config.bSeparateIOThread;
 	ioManager.SetThreadEnabled(ioManagerThreadEnabled);
-	Core_ListenLifecycle(&__IoWakeManager);
-	ioManagerThread = std::thread(&__IoManagerThread);
+	if (ioManagerThreadEnabled) {
+		Core_ListenLifecycle(&__IoWakeManager);
+		ioManagerThread = new std::thread(&__IoManagerThread);
+	}
 
 	__KernelRegisterWaitTypeFuncs(WAITTYPE_ASYNCIO, __IoAsyncBeginCallback, __IoAsyncEndCallback);
 
@@ -733,8 +735,12 @@ void __IoShutdown() {
 	ioManagerThreadEnabled = false;
 	ioManager.SyncThread();
 	ioManager.FinishEventLoop();
-	ioManagerThread.join();
-	ioManager.Shutdown();
+	if (ioManagerThread != nullptr) {
+		ioManagerThread->join();
+		delete ioManagerThread;
+		ioManagerThread = nullptr;
+		ioManager.Shutdown();
+	}
 
 	for (int i = 0; i < PSP_COUNT_FDS; ++i) {
 		asyncParams[i].op = IoAsyncOp::NONE;
diff --git a/UI/GameSettingsScreen.cpp b/UI/GameSettingsScreen.cpp
index 1a9ca4a977de..9d824e28b3b7 100644
--- a/UI/GameSettingsScreen.cpp
+++ b/UI/GameSettingsScreen.cpp
@@ -771,8 +771,10 @@ void GameSettingsScreen::CreateViews() {
 
 	systemSettings->Add(new CheckBox(&g_Config.bFastMemory, sy->T("Fast Memory", "Fast Memory (Unstable)")))->OnClick.Handle(this, &GameSettingsScreen::OnJitAffectingSetting);
 
+	systemSettings->Add(new CheckBox(&g_Config.bSeparateIOThread, sy->T("I/O on thread (experimental)")))->SetEnabled(!PSP_IsInited());
 	static const char *ioTimingMethods[] = { "Fast (lag on slow storage)", "Host (bugs, less lag)", "Simulate UMD delays" };
 	View *ioTimingMethod = systemSettings->Add(new PopupMultiChoice(&g_Config.iIOTimingMethod, sy->T("IO timing method"), ioTimingMethods, 0, ARRAY_SIZE(ioTimingMethods), sy->GetName(), screenManager()));
+	ioTimingMethod->SetEnabledPtr(&g_Config.bSeparateIOThread);
 	systemSettings->Add(new CheckBox(&g_Config.bForceLagSync, sy->T("Force real clock sync (slower, less lag)")));
 	PopupSliderChoice *lockedMhz = systemSettings->Add(new PopupSliderChoice(&g_Config.iLockedCPUSpeed, 0, 1000, sy->T("Change CPU Clock", "Change CPU Clock (unstable)"), screenManager(), sy->T("MHz, 0:default")));
 	lockedMhz->OnChange.Add([&](UI::EventParams &) {