From 252ec7452c4c908537036215c1888f5c5d596bd7 Mon Sep 17 00:00:00 2001
From: Dentomologist <dentomologist@gmail.com>
Date: Sat, 7 Mar 2026 12:33:39 -0800
Subject: [PATCH] PerformanceMetrics: Use HookableEvent for state changed
 callback

Use the normal state changed `HookableEvent` instead of having
`Core::NotifyStateChanged` call `g_perf_metrics.OnEmulationStateChanged`
directly.

The direct call was added in bad78cfed416d89ceb6b0acf6c134d3691b3d624 to
avoid a crash. At the time state changed callbacks were stored in a
vector, and the crash was caused by `g_perf_metric`'s destructor trying
to remove the callback from the already-destroyed vector.

Later a97627e736ff352e031123519c799e65cc98b32c switched state changed
callbacks to use `HookableEvent`, which is specifically designed to
handle the case where a hook outlives its associated event.

Since the workaround is no longer necessary replace it with a standard
`EventHook`.
---
 Source/Core/Core/Core.cpp                      |  3 +--
 Source/Core/VideoCommon/PerformanceMetrics.cpp | 17 +++++++++++------
 Source/Core/VideoCommon/PerformanceMetrics.h   |  7 ++++---
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/Source/Core/Core/Core.cpp b/Source/Core/Core/Core.cpp
index bdae112865..8ee7c44c2b 100644
--- a/Source/Core/Core/Core.cpp
+++ b/Source/Core/Core/Core.cpp
@@ -929,10 +929,9 @@ Common::EventHook AddOnStateChangedCallback(StateChangedCallbackFunc callback)
   return s_state_changed_event.Register(std::move(callback));
 }
 
-void NotifyStateChanged(Core::State state)
+void NotifyStateChanged(const Core::State state)
 {
   s_state_changed_event.Trigger(state);
-  g_perf_metrics.OnEmulationStateChanged(state);
 }
 
 void UpdateWantDeterminism(Core::System& system, bool initial)
diff --git a/Source/Core/VideoCommon/PerformanceMetrics.cpp b/Source/Core/VideoCommon/PerformanceMetrics.cpp
index 0e2e371d4e..cba4beb8c6 100644
--- a/Source/Core/VideoCommon/PerformanceMetrics.cpp
+++ b/Source/Core/VideoCommon/PerformanceMetrics.cpp
@@ -8,11 +8,22 @@
 #include <imgui.h>
 #include <implot.h>
 
+#include "Common/HookableEvent.h"
 #include "Core/Config/GraphicsSettings.h"
+#include "Core/Core.h"
 #include "VideoCommon/VideoConfig.h"
 
 PerformanceMetrics g_perf_metrics;
 
+PerformanceMetrics::PerformanceMetrics()
+{
+  const auto invalidate_counters_last_time = [this](Core::State) {
+    m_fps_counter.InvalidateLastTime();
+    m_vps_counter.InvalidateLastTime();
+  };
+  m_state_change_hook = Core::AddOnStateChangedCallback(invalidate_counters_last_time);
+}
+
 void PerformanceMetrics::Reset()
 {
   m_fps_counter.Reset();
@@ -37,12 +48,6 @@ void PerformanceMetrics::CountVBlank()
   m_vps_counter.Count();
 }
 
-void PerformanceMetrics::OnEmulationStateChanged([[maybe_unused]] Core::State state)
-{
-  m_fps_counter.InvalidateLastTime();
-  m_vps_counter.InvalidateLastTime();
-}
-
 void PerformanceMetrics::CountThrottleSleep(DT sleep)
 {
   m_time_sleeping += sleep;
diff --git a/Source/Core/VideoCommon/PerformanceMetrics.h b/Source/Core/VideoCommon/PerformanceMetrics.h
index 914e6bc82f..71fd339c07 100644
--- a/Source/Core/VideoCommon/PerformanceMetrics.h
+++ b/Source/Core/VideoCommon/PerformanceMetrics.h
@@ -7,7 +7,7 @@
 #include <deque>
 
 #include "Common/CommonTypes.h"
-#include "Core/Core.h"
+#include "Common/HookableEvent.h"
 #include "VideoCommon/PerformanceTracker.h"
 
 namespace Core
@@ -18,7 +18,7 @@ class System;
 class PerformanceMetrics
 {
 public:
-  PerformanceMetrics() = default;
+  PerformanceMetrics();
   ~PerformanceMetrics() = default;
 
   PerformanceMetrics(const PerformanceMetrics&) = delete;
@@ -30,7 +30,6 @@ public:
 
   void CountFrame();
   void CountVBlank();
-  void OnEmulationStateChanged(Core::State state);
 
   // Call from CPU thread.
   void CountThrottleSleep(DT sleep);
@@ -69,6 +68,8 @@ private:
 
   std::deque<PerfSample> m_samples;
   DT m_time_sleeping{};
+
+  Common::EventHook m_state_change_hook;
 };
 
 extern PerformanceMetrics g_perf_metrics;