From 7718f60ba60b398527f1da6679b50c918ae70157 Mon Sep 17 00:00:00 2001
From: stransky <stransky@redhat.com>
Date: Fri, 4 Nov 2022 10:15:23 +0000
Subject: [PATCH] Bug 1796130 [Wayland] Track and release Vsync frame callbacks
 so we don't get frame callback after nsWindow::Destroy() r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D160364
---
 widget/gtk/WaylandVsyncSource.cpp | 34 ++++++++++++++++++++-----------
 widget/gtk/WaylandVsyncSource.h   |  3 ++-
 2 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/widget/gtk/WaylandVsyncSource.cpp b/widget/gtk/WaylandVsyncSource.cpp
index 5ed5d72966ef..2d8748e135dd 100644
--- a/widget/gtk/WaylandVsyncSource.cpp
+++ b/widget/gtk/WaylandVsyncSource.cpp
@@ -38,19 +38,18 @@ namespace mozilla {
 static void WaylandVsyncSourceCallbackHandler(void* aData,
                                               struct wl_callback* aCallback,
                                               uint32_t aTime) {
-  WaylandVsyncSource* context = (WaylandVsyncSource*)aData;
-  wl_callback_destroy(aCallback);
-  context->FrameCallback(aTime);
-}
-
-static void WaylandVsyncSourceCallbackHandler(void* aData, uint32_t aTime) {
-  WaylandVsyncSource* context = (WaylandVsyncSource*)aData;
-  context->FrameCallback(aTime);
+  RefPtr<WaylandVsyncSource> context(static_cast<WaylandVsyncSource*>(aData));
+  context->FrameCallback(aCallback, aTime);
 }
 
 static const struct wl_callback_listener WaylandVsyncSourceCallbackListener = {
     WaylandVsyncSourceCallbackHandler};
 
+static void NativeLayerRootWaylandVsyncCallback(void* aData, uint32_t aTime) {
+  RefPtr<WaylandVsyncSource> context(static_cast<WaylandVsyncSource*>(aData));
+  context->FrameCallback(nullptr, aTime);
+}
+
 static float GetFPS(TimeDuration aVsyncRate) {
   return 1000.0 / aVsyncRate.ToMilliseconds();
 }
@@ -207,7 +206,7 @@ void WaylandVsyncSource::SetupFrameCallback(const MutexAutoLock& aProofOfLock) {
 
   if (mNativeLayerRoot) {
     LOG("  use mNativeLayerRoot");
-    mNativeLayerRoot->RequestFrameCallback(&WaylandVsyncSourceCallbackHandler,
+    mNativeLayerRoot->RequestFrameCallback(&NativeLayerRootWaylandVsyncCallback,
                                            this);
   } else {
     MozContainerSurfaceLock lock(mContainer);
@@ -222,8 +221,9 @@ void WaylandVsyncSource::SetupFrameCallback(const MutexAutoLock& aProofOfLock) {
     }
 
     LOG("  register frame callback");
-    wl_callback* callback = wl_surface_frame(surface);
-    wl_callback_add_listener(callback, &WaylandVsyncSourceCallbackListener,
+    MozClearPointer(mCallback, wl_callback_destroy);
+    mCallback = wl_surface_frame(surface);
+    wl_callback_add_listener(mCallback, &WaylandVsyncSourceCallbackListener,
                              this);
     wl_surface_commit(surface);
     wl_display_flush(WaylandDisplayGet()->GetDisplay());
@@ -274,7 +274,7 @@ void WaylandVsyncSource::IdleCallback() {
   window->NotifyOcclusionState(OcclusionState::OCCLUDED);
 }
 
-void WaylandVsyncSource::FrameCallback(uint32_t aTime) {
+void WaylandVsyncSource::FrameCallback(wl_callback* aCallback, uint32_t aTime) {
   LOG("WaylandVsyncSource::FrameCallback");
   MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
 
@@ -282,11 +282,20 @@ void WaylandVsyncSource::FrameCallback(uint32_t aTime) {
     // This might enable vsync.
     RefPtr window = mWindow;
     window->NotifyOcclusionState(OcclusionState::VISIBLE);
+    // NotifyOcclusionState can destroy us.
+    if (window->IsDestroyed()) {
+      return;
+    }
   }
 
   MutexAutoLock lock(mMutex);
   mCallbackRequested = false;
 
+  if (aCallback) {
+    MOZ_RELEASE_ASSERT(aCallback == mCallback);
+    MozClearPointer(mCallback, wl_callback_destroy);
+  }
+
   if (!mVsyncEnabled || !mMonitorEnabled) {
     // We are unwanted by either our creator or our consumer, so we just stop
     // here without setting up a new frame callback.
@@ -392,6 +401,7 @@ void WaylandVsyncSource::Shutdown() {
   mVsyncEnabled = false;
   mCallbackRequested = false;
   MozClearHandleID(mIdleTimerID, g_source_remove);
+  MozClearPointer(mCallback, wl_callback_destroy);
 }
 
 }  // namespace mozilla
diff --git a/widget/gtk/WaylandVsyncSource.h b/widget/gtk/WaylandVsyncSource.h
index 71947b380497..faed35021f84 100644
--- a/widget/gtk/WaylandVsyncSource.h
+++ b/widget/gtk/WaylandVsyncSource.h
@@ -55,7 +55,7 @@ class WaylandVsyncSource final : public gfx::VsyncSource {
   void EnableMonitor();
   void DisableMonitor();
 
-  void FrameCallback(uint32_t aTime);
+  void FrameCallback(wl_callback* aCallback, uint32_t aTime);
   void IdleCallback();
 
   TimeDuration GetVsyncRate() override;
@@ -87,6 +87,7 @@ class WaylandVsyncSource final : public gfx::VsyncSource {
   TimeDuration mVsyncRate MOZ_GUARDED_BY(mMutex);
   TimeStamp mLastVsyncTimeStamp MOZ_GUARDED_BY(mMutex);
   guint mIdleTimerID MOZ_GUARDED_BY(mMutex) = 0;
+  wl_callback* mCallback MOZ_GUARDED_BY(mMutex) = nullptr;
 
   nsWindow* const mWindow;  // Main thread only, except for logging.
   const guint mIdleTimeout;