From 31fa31dc3dec3cb500144305f34c5928c55a19e4 Mon Sep 17 00:00:00 2001
From: Sour <mesenemu@gmail.com>
Date: Mon, 8 Jul 2019 22:06:12 -0400
Subject: [PATCH] SPC: Implemented SLEEP/STOP behavior to avoid lock up when a
 crashed SPC program calls them

---
 Core/Spc.Instructions.cpp | 4 ++++
 Core/Spc.cpp              | 8 ++++++++
 Core/SpcTypes.h           | 2 ++
 UI/Interop/DebugApi.cs    | 1 +
 4 files changed, 15 insertions(+)

diff --git a/Core/Spc.Instructions.cpp b/Core/Spc.Instructions.cpp
index 470ab67..3e3e2b9 100644
--- a/Core/Spc.Instructions.cpp
+++ b/Core/Spc.Instructions.cpp
@@ -2105,9 +2105,13 @@ void Spc::NOP()
 void Spc::SLEEP()
 {
 	//WAI
+	_state.StopState = CpuStopState::WaitingForIrq;
+	EndOp();
 }
 
 void Spc::STOP()
 {
 	//STP
+	_state.StopState = CpuStopState::Stopped;
+	EndOp();
 }
diff --git a/Core/Spc.cpp b/Core/Spc.cpp
index 82be87f..2e33154 100644
--- a/Core/Spc.cpp
+++ b/Core/Spc.cpp
@@ -26,6 +26,7 @@ Spc::Spc(shared_ptr<Console> console)
 	_state.RomEnabled = true;
 	_state.SP = 0xFF;
 	_state.PC = ReadWord(Spc::ResetVector);
+	_state.StopState = CpuStopState::Running;
 
 	_opCode = 0;
 	_opStep = SpcOpStep::ReadOpCode;
@@ -49,6 +50,8 @@ Spc::~Spc()
 
 void Spc::Reset()
 {
+	_state.StopState = CpuStopState::Running;
+
 	_state.Timer0.Reset();
 	_state.Timer1.Reset();
 	_state.Timer2.Reset();
@@ -279,6 +282,11 @@ void Spc::CpuWriteRegister(uint32_t addr, uint8_t value)
 
 void Spc::Run()
 {
+	if(_state.StopState != CpuStopState::Running) {
+		//STOP or SLEEP were executed - execution is stopped forever.
+		return;
+	}
+
 	uint64_t targetCycle = (uint64_t)(_memoryManager->GetMasterClock() * _clockRatio);
 	while(_state.Cycle < targetCycle) {
 		if(_opStep == SpcOpStep::ReadOpCode) {
diff --git a/Core/SpcTypes.h b/Core/SpcTypes.h
index 23892f4..5114e4c 100644
--- a/Core/SpcTypes.h
+++ b/Core/SpcTypes.h
@@ -1,6 +1,7 @@
 #pragma once
 #include "stdafx.h"
 #include "SpcTimer.h"
+#include "CpuTypes.h"
 
 struct SpcState
 {
@@ -17,6 +18,7 @@ struct SpcState
 	uint8_t InternalSpeed;
 	uint8_t ExternalSpeed;
 	bool TimersEnabled;
+	CpuStopState StopState;
 
 	uint8_t DspReg;
 	uint8_t OutputReg[4];
diff --git a/UI/Interop/DebugApi.cs b/UI/Interop/DebugApi.cs
index 0b4038d..96b7afa 100644
--- a/UI/Interop/DebugApi.cs
+++ b/UI/Interop/DebugApi.cs
@@ -363,6 +363,7 @@ namespace Mesen.GUI
 		public byte InternalSpeed;
 		public byte ExternalSpeed;
 		[MarshalAs(UnmanagedType.I1)] public bool TimersEnabled;
+		public CpuStopState StopState;
 
 		public byte DspReg;