From cc3aa959265480e1990b10ee37ebf1c0ade3da64 Mon Sep 17 00:00:00 2001
From: Fernando Sahmkow <fsahmkow27@gmail.com>
Date: Thu, 27 Feb 2020 10:47:02 -0400
Subject: [PATCH] NVFlinger: Lock race condition between CPU, Host Timing,
VSync.
---
src/core/hle/service/nvflinger/nvflinger.cpp | 2 ++
src/core/hle/service/nvflinger/nvflinger.h | 7 +++++++
src/core/hle/service/vi/vi.cpp | 2 ++
3 files changed, 11 insertions(+)
diff --git a/src/core/hle/service/nvflinger/nvflinger.cpp b/src/core/hle/service/nvflinger/nvflinger.cpp
index aaf28995db..b97f713500 100644
--- a/src/core/hle/service/nvflinger/nvflinger.cpp
+++ b/src/core/hle/service/nvflinger/nvflinger.cpp
@@ -36,10 +36,12 @@ NVFlinger::NVFlinger(Core::System& system) : system(system) {
displays.emplace_back(2, "Edid", system);
displays.emplace_back(3, "Internal", system);
displays.emplace_back(4, "Null", system);
+ guard = std::make_shared<std::mutex>();
// Schedule the screen composition events
composition_event =
Core::Timing::CreateEvent("ScreenComposition", [this](u64 userdata, s64 ns_late) {
+ Lock();
Compose();
const auto ticks = GetNextTicks();
this->system.CoreTiming().ScheduleEvent(std::max<s64>(0LL, ticks - ns_late),
diff --git a/src/core/hle/service/nvflinger/nvflinger.h b/src/core/hle/service/nvflinger/nvflinger.h
index 57a21f33b6..02c081494d 100644
--- a/src/core/hle/service/nvflinger/nvflinger.h
+++ b/src/core/hle/service/nvflinger/nvflinger.h
@@ -5,6 +5,7 @@
#pragma once
#include <memory>
+#include <mutex>
#include <optional>
#include <string>
#include <string_view>
@@ -79,6 +80,10 @@ public:
s64 GetNextTicks() const;
+ std::unique_lock<std::mutex> Lock() {
+ return std::unique_lock{*guard};
+ }
+
private:
/// Finds the display identified by the specified ID.
VI::Display* FindDisplay(u64 display_id);
@@ -108,6 +113,8 @@ private:
/// Event that handles screen composition.
std::shared_ptr<Core::Timing::EventType> composition_event;
+ std::shared_ptr<std::mutex> guard;
+
Core::System& system;
};
diff --git a/src/core/hle/service/vi/vi.cpp b/src/core/hle/service/vi/vi.cpp
index 46e14c2a3f..1570920746 100644
--- a/src/core/hle/service/vi/vi.cpp
+++ b/src/core/hle/service/vi/vi.cpp
@@ -511,6 +511,7 @@ private:
LOG_DEBUG(Service_VI, "called. id=0x{:08X} transaction={:X}, flags=0x{:08X}", id,
static_cast<u32>(transaction), flags);
+ nv_flinger->Lock();
auto& buffer_queue = nv_flinger->FindBufferQueue(id);
switch (transaction) {
@@ -550,6 +551,7 @@ private:
[=](std::shared_ptr<Kernel::Thread> thread, Kernel::HLERequestContext& ctx,
Kernel::ThreadWakeupReason reason) {
// Repeat TransactParcel DequeueBuffer when a buffer is available
+ nv_flinger->Lock();
auto& buffer_queue = nv_flinger->FindBufferQueue(id);
auto result = buffer_queue.DequeueBuffer(width, height);
ASSERT_MSG(result != std::nullopt, "Could not dequeue buffer.");