From 30a60018a0aa44c3a4f550e2cefa5e311a5c1d33 Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Sat, 20 Jan 2018 12:05:30 -0800
Subject: [PATCH] GLES: Fix race crash on shutdown.

This happens when there are pointers in step commands that get freed.
---
 GPU/GLES/GPU_GLES.cpp                 |  4 ++++
 ext/native/thin3d/GLRenderManager.cpp | 27 +++++++++++++++++++++++++++
 ext/native/thin3d/GLRenderManager.h   |  4 ++++
 3 files changed, 35 insertions(+)

diff --git a/GPU/GLES/GPU_GLES.cpp b/GPU/GLES/GPU_GLES.cpp
index 5417a24a8..f58c47ddb 100644
--- a/GPU/GLES/GPU_GLES.cpp
+++ b/GPU/GLES/GPU_GLES.cpp
@@ -184,6 +184,10 @@ GPU_GLES::GPU_GLES(GraphicsContext *gfxCtx, Draw::DrawContext *draw)
 }
 
 GPU_GLES::~GPU_GLES() {
+	GLRenderManager *render = (GLRenderManager *)draw_->GetNativeObject(Draw::NativeObject::RENDER_MANAGER);
+	render->Wipe();
+	render->WaitUntilQueueIdle();
+
 	framebufferManagerGL_->DestroyAllFBOs();
 	shaderManagerGL_->ClearCache(true);
 	depalShaderCache_.Clear();
diff --git a/ext/native/thin3d/GLRenderManager.cpp b/ext/native/thin3d/GLRenderManager.cpp
index 33990e3db..d272f2571 100644
--- a/ext/native/thin3d/GLRenderManager.cpp
+++ b/ext/native/thin3d/GLRenderManager.cpp
@@ -148,10 +148,12 @@ void GLRenderManager::StopThread() {
 				Crash();
 			}
 			frameData.readyForRun = false;
+			frameData.readyForSubmit = false;
 			for (size_t i = 0; i < frameData.steps.size(); i++) {
 				delete frameData.steps[i];
 			}
 			frameData.steps.clear();
+			frameData.initSteps.clear();
 
 			std::unique_lock<std::mutex> lock(frameData.push_mutex);
 			while (!frameData.readyForFence) {
@@ -306,6 +308,7 @@ void GLRenderManager::BeginFrame() {
 			frameData.push_condVar.wait(lock);
 		}
 		frameData.readyForFence = false;
+		frameData.readyForSubmit = true;
 	}
 
 	VLOG("PUSH: Fencing %d", curFrame);
@@ -381,7 +384,9 @@ void GLRenderManager::Submit(int frame, bool triggerFence) {
 		VLOG("PULL: Frame %d.readyForFence = true", frame);
 
 		std::unique_lock<std::mutex> lock(frameData.push_mutex);
+		assert(frameData.readyForSubmit);
 		frameData.readyForFence = true;
+		frameData.readyForSubmit = false;
 		frameData.push_condVar.notify_all();
 	}
 }
@@ -466,6 +471,7 @@ void GLRenderManager::FlushSync() {
 			frameData.push_condVar.wait(lock);
 		}
 		frameData.readyForFence = false;
+		frameData.readyForSubmit = true;
 	}
 }
 
@@ -484,17 +490,38 @@ void GLRenderManager::EndSyncFrame(int frame) {
 	if (useThread_) {
 		std::unique_lock<std::mutex> lock(frameData.push_mutex);
 		frameData.readyForFence = true;
+		frameData.readyForSubmit = true;
 		frameData.push_condVar.notify_all();
 	}
 }
 
 void GLRenderManager::Wipe() {
+	initSteps_.clear();
 	for (auto step : steps_) {
 		delete step;
 	}
 	steps_.clear();
 }
 
+void GLRenderManager::WaitUntilQueueIdle() {
+	if (!useThread_) {
+		// Must be idle, nothing to do.
+		return;
+	}
+
+	// Just wait for all frames to be ready.
+	for (int i = 0; i < MAX_INFLIGHT_FRAMES; i++) {
+		FrameData &frameData = frameData_[i];
+
+		std::unique_lock<std::mutex> lock(frameData.push_mutex);
+		// Ignore unsubmitted frames.
+		while (!frameData.readyForFence && !frameData.readyForSubmit) {
+			VLOG("PUSH: Waiting for frame[%d].readyForFence = 1 (wait idle)", i);
+			frameData.push_condVar.wait(lock);
+		}
+	}
+}
+
 GLPushBuffer::GLPushBuffer(GLRenderManager *render, GLuint target, size_t size) : render_(render), target_(target), size_(size) {
 	bool res = AddBuffer();
 	assert(res);
diff --git a/ext/native/thin3d/GLRenderManager.h b/ext/native/thin3d/GLRenderManager.h
index abc4fb7ce..703cda773 100644
--- a/ext/native/thin3d/GLRenderManager.h
+++ b/ext/native/thin3d/GLRenderManager.h
@@ -211,6 +211,9 @@ public:
 	// Zaps queued up commands. Use if you know there's a risk you've queued up stuff that has already been deleted. Can happen during in-game shutdown.
 	void Wipe();
 
+	// Wait until no frames are pending.  Use during shutdown before freeing pointers.
+	void WaitUntilQueueIdle();
+
 	// Creation commands. These were not needed in Vulkan since there we can do that on the main thread.
 	GLRTexture *CreateTexture(GLenum target) {
 		GLRInitStep step{ GLRInitStepType::CREATE_TEXTURE };
@@ -676,6 +679,7 @@ private:
 
 		bool readyForFence = true;
 		bool readyForRun = false;
+		bool readyForSubmit = false;
 		bool skipSwap = false;
 		GLRRunType type = GLRRunType::END;