From 2bec3bf3acca6ba235cd774e3244c2bc009e3a89 Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Sat, 10 Feb 2018 16:12:33 -0800
Subject: [PATCH] Windows: Trigger StopThread() on shutdown.

Otherwise, we end up hanging in the loop waiting for emuThreadState to
become STOPPED.  It actually has, but ThreadFrame() will block until a new
frame is queued... while will never happen, because the emuthread has
stopped.
---
 Common/GraphicsContext.h         | 1 +
 Windows/EmuThread.cpp            | 3 +++
 Windows/GPU/WindowsGLContext.cpp | 5 +++++
 Windows/GPU/WindowsGLContext.h   | 1 +
 4 files changed, 10 insertions(+)

diff --git a/Common/GraphicsContext.h b/Common/GraphicsContext.h
index 66afcd94da..5dfec7f6d9 100644
--- a/Common/GraphicsContext.h
+++ b/Common/GraphicsContext.h
@@ -32,6 +32,7 @@ public:
 	virtual void ThreadStart() {}
 	virtual bool ThreadFrame() { return true; }
 	virtual void ThreadEnd() {}
+	virtual void StopThread() {}
 
 	virtual Draw::DrawContext *GetDrawContext() = 0;
 };
diff --git a/Windows/EmuThread.cpp b/Windows/EmuThread.cpp
index 5b9d1faca5..4e18eb1f53 100644
--- a/Windows/EmuThread.cpp
+++ b/Windows/EmuThread.cpp
@@ -86,6 +86,9 @@ static void EmuThreadFunc(GraphicsContext *graphicsContext) {
 	emuThreadState = (int)EmuThreadState::STOPPED;
 
 	NativeShutdownGraphics();
+
+	// Ask the main thread to stop.  This prevents a hang on a race condition.
+	graphicsContext->StopThread();
 }
 
 static void EmuThreadStart(GraphicsContext *graphicsContext) {
diff --git a/Windows/GPU/WindowsGLContext.cpp b/Windows/GPU/WindowsGLContext.cpp
index 7962d3a817..b5dfc831d0 100644
--- a/Windows/GPU/WindowsGLContext.cpp
+++ b/Windows/GPU/WindowsGLContext.cpp
@@ -432,3 +432,8 @@ bool WindowsGLContext::ThreadFrame() {
 void WindowsGLContext::ThreadEnd() {
 	renderManager_->ThreadEnd();
 }
+
+void WindowsGLContext::StopThread() {
+	renderManager_->WaitUntilQueueIdle();
+	renderManager_->StopThread();
+}
diff --git a/Windows/GPU/WindowsGLContext.h b/Windows/GPU/WindowsGLContext.h
index 38c9494947..1303aece79 100644
--- a/Windows/GPU/WindowsGLContext.h
+++ b/Windows/GPU/WindowsGLContext.h
@@ -29,6 +29,7 @@ public:
 	void ThreadStart() override;
 	void ThreadEnd() override;
 	bool ThreadFrame() override;
+	void StopThread() override;
 
 	Draw::DrawContext *GetDrawContext() override { return draw_; }