From 2ac5bcff1fd4d45ed8a807bf80bc73d147988e9f Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Sat, 14 Sep 2013 18:43:23 -0700
Subject: [PATCH] Process savestates during single stepping.

This way we can handle them on the same thread, without weird delays.
---
 Core/Core.cpp      | 41 ++++++++++++++++++++++++++++-------------
 Core/Core.h        |  1 +
 Core/SaveState.cpp | 11 +++--------
 Core/System.cpp    |  3 ++-
 4 files changed, 34 insertions(+), 22 deletions(-)

diff --git a/Core/Core.cpp b/Core/Core.cpp
index c1ef112f69..a654001444 100644
--- a/Core/Core.cpp
+++ b/Core/Core.cpp
@@ -25,6 +25,7 @@
 #include "Core/Core.h"
 #include "Core/Config.h"
 #include "Core/MemMap.h"
+#include "Core/SaveState.h"
 #include "Core/System.h"
 #include "Core/MIPS/MIPS.h"
 #ifdef _WIN32
@@ -36,10 +37,11 @@
 
 #include "Core/Debugger/Breakpoints.h"
 
-event m_hStepEvent;
-recursive_mutex m_hStepMutex;
-event m_hInactiveEvent;
-recursive_mutex m_hInactiveMutex;
+static event m_hStepEvent;
+static recursive_mutex m_hStepMutex;
+static event m_hInactiveEvent;
+static recursive_mutex m_hInactiveMutex;
+static bool singleStepPending = false;
 
 #ifdef _WIN32
 InputState input_state;
@@ -151,6 +153,12 @@ void Core_RunLoop()
 }
 
 void Core_DoSingleStep()
+{
+	singleStepPending = true;
+	m_hStepEvent.notify_one();
+}
+
+void Core_UpdateSingleStep()
 {
 	m_hStepEvent.notify_one();
 }
@@ -175,18 +183,22 @@ reswitch:
 		switch (coreState)
 		{
 		case CORE_RUNNING:
-			//1: enter a fast runloop
+			// enter a fast runloop
 			Core_RunLoop();
 			break;
 
 		// We should never get here on Android.
 		case CORE_STEPPING:
+			singleStepPending = false;
 			if (coreStatePending) {
 				coreStatePending = false;
 				m_hInactiveEvent.notify_one();
 			}
 
-			//1: wait for step command..
+			// Check if there's any pending savestate actions.
+			SaveState::Process();
+
+			// wait for step command..
 #if defined(USING_QT_UI) || defined(_DEBUG)
 			host->UpdateDisassembly();
 			host->UpdateMemView();
@@ -198,18 +210,21 @@ reswitch:
 #if defined(USING_QT_UI) || defined(_DEBUG)
 			host->SendCoreWait(false);
 #endif
-			if (coreState == CORE_POWERDOWN)
-				return;
-			if (coreState != CORE_STEPPING)
 #if defined(USING_QT_UI) && !defined(USING_GLES2)
+			if (coreState != CORE_STEPPING)
 				return;
-#else
-				goto reswitch;
 #endif
+			// No step pending?  Let's go back to the wait.
+			if (!singleStepPending || coreState != CORE_STEPPING) {
+				if (coreState == CORE_POWERDOWN) {
+					return;
+				}
+				goto reswitch;
+			}
 
 			currentCPU = &mipsr4k;
 			Core_SingleStep();
-			//4: update disasm dialog
+			// update disasm dialog
 #if defined(USING_QT_UI) || defined(_DEBUG)
 			host->UpdateDisassembly();
 			host->UpdateMemView();
@@ -218,7 +233,7 @@ reswitch:
 
 		case CORE_POWERDOWN:
 		case CORE_ERROR:
-			//1: Exit loop!!
+			// Exit loop!!
 			if (coreStatePending) {
 				coreStatePending = false;
 				m_hInactiveEvent.notify_one();
diff --git a/Core/Core.h b/Core/Core.h
index b26103b740..70d21945d0 100644
--- a/Core/Core.h
+++ b/Core/Core.h
@@ -28,6 +28,7 @@ void Core_ErrorPause();
 // called from gui
 void Core_EnableStepping(bool step);
 void Core_DoSingleStep();
+void Core_UpdateSingleStep();
 
 void Core_Halt(const char *msg);
 
diff --git a/Core/SaveState.cpp b/Core/SaveState.cpp
index c424434af6..83282f5e4e 100644
--- a/Core/SaveState.cpp
+++ b/Core/SaveState.cpp
@@ -83,15 +83,10 @@ namespace SaveState
 		std::lock_guard<std::recursive_mutex> guard(mutex);
 		pending.push_back(op);
 
-		// Don't actually run it until next CoreTiming::Advance().
+		// Don't actually run it until next frame.
 		// It's possible there might be a duplicate but it won't hurt us.
-		if (Core_IsInactive() && __KernelIsRunning()) {
-			// Warning: this may run on a different thread.
-			needsProcess = true;
-			Process();
-		} else {
-			needsProcess = true;
-		}
+		needsProcess = true;
+		Core_UpdateSingleStep();
 	}
 
 	void Load(const std::string &filename, Callback callback, void *cbUserData)
diff --git a/Core/System.cpp b/Core/System.cpp
index f652ad960c..a7ff591c50 100644
--- a/Core/System.cpp
+++ b/Core/System.cpp
@@ -252,6 +252,7 @@ void Core_UpdateState(CoreState newState) {
 	if ((coreState == CORE_RUNNING || coreState == CORE_NEXTFRAME) && newState != CORE_RUNNING)
 		coreStatePending = true;
 	coreState = newState;
+	Core_UpdateSingleStep();
 }
 
 bool PSP_Init(const CoreParameter &coreParam, std::string *error_string) {
@@ -286,7 +287,7 @@ bool PSP_IsInited() {
 
 void PSP_Shutdown() {
 	if (coreState == CORE_RUNNING)
-		coreState = CORE_ERROR;
+		Core_UpdateState(CORE_ERROR);
 	if (cpuThread != NULL) {
 		CPU_SetState(CPU_THREAD_SHUTDOWN);
 		CPU_WaitStatus(&CPU_IsShutdown);