From 18447ac6ac48046cbb3b7bc1dc5a397ca1c70952 Mon Sep 17 00:00:00 2001
From: PabloMK7 <hackyglitch2@gmail.com>
Date: Wed, 7 May 2025 19:31:13 +0200
Subject: [PATCH] Fix savestates with the OpenGL renderer

---
 src/core/core.cpp                    | 12 ++++++++++++
 src/core/hle/kernel/kernel.h         |  3 +++
 src/core/hle/kernel/thread.cpp       | 14 +++++++++++++-
 src/core/hle/kernel/thread.h         |  2 +-
 src/core/hle/service/gsp/gsp_gpu.cpp |  3 +++
 src/core/hle/service/gsp/gsp_gpu.h   | 12 +++++++++++-
 6 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/src/core/core.cpp b/src/core/core.cpp
index 98ac85eba..d5064787d 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -826,6 +826,18 @@ void System::serialize(Archive& ar, const unsigned int file_version) {
         auto gsp = service_manager->GetService<Service::GSP::GSP_GPU>("gsp::Gpu");
         gpu->SetInterruptHandler(
             [gsp](Service::GSP::InterruptId interrupt_id) { gsp->SignalInterrupt(interrupt_id); });
+
+        // Switch the shader cache to the title running when the savestate was created
+        const u32 thread_id = gsp->GetActiveClientThreadId();
+        if (thread_id != std::numeric_limits<u32>::max()) {
+            const auto thread = kernel->GetThreadByID(thread_id);
+            if (thread) {
+                const std::shared_ptr<Kernel::Process> process = thread->owner_process.lock();
+                if (process) {
+                    gpu->Renderer().Rasterizer()->SwitchDiskResources(process->codeset->program_id);
+                }
+            }
+        }
     } else {
         u32 cheats_pid = cheat_engine.GetConnectedPID();
         ar & cheats_pid;
diff --git a/src/core/hle/kernel/kernel.h b/src/core/hle/kernel/kernel.h
index 5704cdda0..d3b0bc53e 100644
--- a/src/core/hle/kernel/kernel.h
+++ b/src/core/hle/kernel/kernel.h
@@ -270,6 +270,9 @@ public:
     /// Retrieves a process from the current list of processes.
     std::shared_ptr<Process> GetProcessById(u32 process_id) const;
 
+    /// Retrieves a thread from the current list of threads.
+    std::shared_ptr<Thread> GetThreadByID(u32 thread_id) const;
+
     std::span<const std::shared_ptr<Process>> GetProcessList() const {
         return process_list;
     }
diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp
index 0170cef3d..22789369b 100644
--- a/src/core/hle/kernel/thread.cpp
+++ b/src/core/hle/kernel/thread.cpp
@@ -528,8 +528,20 @@ ThreadManager::~ThreadManager() {
     }
 }
 
-std::span<const std::shared_ptr<Thread>> ThreadManager::GetThreadList() {
+std::span<const std::shared_ptr<Thread>> ThreadManager::GetThreadList() const {
     return thread_list;
 }
 
+std::shared_ptr<Thread> KernelSystem::GetThreadByID(u32 thread_id) const {
+    for (u32 core_id = 0; core_id < Core::System::GetInstance().GetNumCores(); core_id++) {
+        const auto thread_list = GetThreadManager(core_id).GetThreadList();
+        for (auto& thread : thread_list) {
+            if (thread->thread_id == thread_id) {
+                return thread;
+            }
+        }
+    }
+    return nullptr;
+}
+
 } // namespace Kernel
diff --git a/src/core/hle/kernel/thread.h b/src/core/hle/kernel/thread.h
index 09291d567..8853384f4 100644
--- a/src/core/hle/kernel/thread.h
+++ b/src/core/hle/kernel/thread.h
@@ -124,7 +124,7 @@ public:
     /**
      * Get a const reference to the thread list for debug use
      */
-    std::span<const std::shared_ptr<Thread>> GetThreadList();
+    std::span<const std::shared_ptr<Thread>> GetThreadList() const;
 
     void SetCPU(Core::ARM_Interface& cpu_) {
         cpu = &cpu_;
diff --git a/src/core/hle/service/gsp/gsp_gpu.cpp b/src/core/hle/service/gsp/gsp_gpu.cpp
index 6887de663..35157cd08 100644
--- a/src/core/hle/service/gsp/gsp_gpu.cpp
+++ b/src/core/hle/service/gsp/gsp_gpu.cpp
@@ -626,6 +626,7 @@ Result GSP_GPU::AcquireGpuRight(const Kernel::HLERequestContext& ctx,
     }
 
     active_thread_id = session_data->thread_id;
+    active_client_thread_id = ctx.ClientThread()->thread_id;
     return ResultSuccess;
 }
 
@@ -654,6 +655,7 @@ void GSP_GPU::ReleaseRight(const SessionData* session_data) {
     ASSERT_MSG(active_thread_id == session_data->thread_id,
                "Wrong thread tried to release GPU right");
     active_thread_id = std::numeric_limits<u32>::max();
+    active_client_thread_id = std::numeric_limits<u32>::max();
 }
 
 void GSP_GPU::ReleaseRight(Kernel::HLERequestContext& ctx) {
@@ -723,6 +725,7 @@ void GSP_GPU::serialize(Archive& ar, const unsigned int) {
     ar& boost::serialization::base_object<Kernel::SessionRequestHandler>(*this);
     ar & shared_memory;
     ar & active_thread_id;
+    ar & active_client_thread_id;
     ar & first_initialization;
     ar & used_thread_ids;
     ar & saved_vram;
diff --git a/src/core/hle/service/gsp/gsp_gpu.h b/src/core/hle/service/gsp/gsp_gpu.h
index e1bc5eb4f..f5f810c44 100644
--- a/src/core/hle/service/gsp/gsp_gpu.h
+++ b/src/core/hle/service/gsp/gsp_gpu.h
@@ -1,4 +1,4 @@
-// Copyright 2014 Citra Emulator Project
+// Copyright Citra Emulator Project / Azahar Emulator Project
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
@@ -123,6 +123,13 @@ public:
         return active_thread_id;
     }
 
+    /**
+     * Retreives the ID of the client thread with GPU rights.
+     */
+    u32 GetActiveClientThreadId() {
+        return active_client_thread_id;
+    }
+
 private:
     /**
      * Signals that the specified interrupt type has occurred to userland code for the specified GSP
@@ -378,6 +385,9 @@ private:
     /// Thread id that currently has GPU rights or std::numeric_limits<u32>::max() if none.
     u32 active_thread_id = std::numeric_limits<u32>::max();
 
+    /// Thread id of the client thread that has GPU rights
+    u32 active_client_thread_id = std::numeric_limits<u32>::max();
+
     bool first_initialization = true;
 
     /// VRAM copy saved using SaveVramSysArea.