From efe6edcaf8eba601dff99ec6ad4457c8a4442f86 Mon Sep 17 00:00:00 2001

From: Georges Basile Stavracas Neto <gbsneto@gnome.org>

Date: Thu, 27 May 2021 20:02:53 -0300

Subject: [PATCH 33/36] Client: Always destroy frame callback in the actual

 callback

It's good hygiene to destroy all frame callbacks. Destroy the

frame callback and cleanup the mFrameCallback class member in

the callback itself. The callback destruction happens before

calling handleFrameCallback() to avoid the theoretical case

where another frame callback is queued by handleFrameCallback(),

and then immediately destroyed in the callback handler.

* asturmlechner 2021-09-27:

  Conflict resolved from non-backported commit in dev branch:

  93058de8d7e7c2f320c22b3bd898aa06cf5babcd

Change-Id: Ide6dc95e3402932c58bfc088a9d471fda821e9a1

Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

(cherry picked from commit 42cdc61a93cf2acb09936aebb5e431fdbc0a26c6)

---

 src/client/qwaylandwindow.cpp | 11 +++++------

 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/client/qwaylandwindow.cpp b/src/client/qwaylandwindow.cpp

index 85307875..c020a58f 100644

--- a/src/client/qwaylandwindow.cpp

+++ b/src/client/qwaylandwindow.cpp

@@ -622,9 +622,13 @@ void QWaylandWindow::commit()

 const wl_callback_listener QWaylandWindow::callbackListener = {

     [](void *data, wl_callback *callback, uint32_t time) {

-        Q_UNUSED(callback);

         Q_UNUSED(time);

         auto *window = static_cast<QWaylandWindow*>(data);

+

+        Q_ASSERT(callback == window->mFrameCallback);

+        wl_callback_destroy(callback);

+        window->mFrameCallback = nullptr;

+

         window->handleFrameCallback();

     }

 };

@@ -1179,11 +1183,6 @@ void QWaylandWindow::handleUpdate()

     if (!mSurface)

         return;

-    if (mFrameCallback) {

-        wl_callback_destroy(mFrameCallback);

-        mFrameCallback = nullptr;

-    }

-

     QMutexLocker locker(mFrameQueue.mutex);

     struct ::wl_surface *wrappedSurface = reinterpret_cast<struct ::wl_surface *>(wl_proxy_create_wrapper(mSurface->object()));

     wl_proxy_set_queue(reinterpret_cast<wl_proxy *>(wrappedSurface), mFrameQueue.queue);

-- 

2.33.1