From 2f49a551c13934b9dc815bbda67a45098f0482a7 Mon Sep 17 00:00:00 2001
From: Jesse Talavera-Greenberg <jesse@jesse.tg>
Date: Thu, 26 Oct 2023 09:37:39 -0400
Subject: [PATCH] Lock the GPU3D state when rendering on the render thread or
 serializing it

---
 src/GPU3D.cpp      | 13 +++++++++++++
 src/GPU3D_Soft.cpp |  3 +++
 2 files changed, 16 insertions(+)

diff --git a/src/GPU3D.cpp b/src/GPU3D.cpp
index 41229424..662a3287 100644
--- a/src/GPU3D.cpp
+++ b/src/GPU3D.cpp
@@ -275,6 +275,7 @@ u32 RenderNumPolygons;
 u32 FlushRequest;
 u32 FlushAttributes;
 
+Platform::Mutex* StateLock;
 std::unique_ptr<GPU3D::Renderer3D> CurrentRenderer = {};
 
 bool AbortFrame;
@@ -294,12 +295,22 @@ void Vertex::DoSavestate(Savestate* file) noexcept
 
 bool Init()
 {
+    if (StateLock)
+    {
+        Platform::Mutex_Free(StateLock);
+    }
+    StateLock = Platform::Mutex_Create();
     return true;
 }
 
 void DeInit()
 {
     CurrentRenderer = nullptr;
+    if (StateLock)
+    {
+        Platform::Mutex_Free(StateLock);
+        StateLock = nullptr;
+    }
 }
 
 void ResetRenderingState()
@@ -410,6 +421,7 @@ void DoSavestate(Savestate* file)
     if (softRenderer && softRenderer->IsThreaded())
     {
         softRenderer->SetupRenderThread();
+        Platform::Mutex_Lock(StateLock);
     }
 
     CmdFIFO.DoSavestate(file);
@@ -643,6 +655,7 @@ void DoSavestate(Savestate* file)
     file->Var32(&TexPalette);
     if (softRenderer && softRenderer->IsThreaded())
     {
+        Platform::Mutex_Unlock(StateLock);
         softRenderer->EnableRenderThread();
     }
 }
diff --git a/src/GPU3D_Soft.cpp b/src/GPU3D_Soft.cpp
index 33b278be..905ede88 100644
--- a/src/GPU3D_Soft.cpp
+++ b/src/GPU3D_Soft.cpp
@@ -1736,6 +1736,7 @@ void SoftRenderer::RestartFrame()
     EnableRenderThread();
 }
 
+extern Platform::Mutex* StateLock;
 void SoftRenderer::RenderThreadFunc()
 {
     for (;;)
@@ -1750,8 +1751,10 @@ void SoftRenderer::RenderThreadFunc()
         }
         else
         {
+            Platform::Mutex_Lock(StateLock);
             ClearBuffers();
             RenderPolygons(true, &RenderPolygonRAM[0], RenderNumPolygons);
+            Platform::Mutex_Unlock(StateLock);
         }
 
         Platform::Semaphore_Post(Sema_RenderDone);