1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
From f4d3297e6705cc524729d629bf94db11841dbb24 Mon Sep 17 00:00:00 2001
From: Simon Yuan <simon.yuan@navico.com>
Date: Thu, 7 Nov 2019 09:22:37 +1300
Subject: [PATCH] Fix timer leak and a potential race
The callback timer is now killed immediately before starting a new timer, this
makes sure there is always a single active callback timer. It's unclear why
killing the timer in a separate lambda doesn't always kill the timer in time,
the hypothesis is that if killing the timer comes after starting a new one, then
the previous timer is now left dangling. Whatever the reason is, it makes even
more sense to kill the timer in the same lamda and immediately before starting a
new timer anyway.
---
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 0df99d9f..93b46bf1 100644
--- a/src/client/qwaylandwindow.cpp
+++ b/src/client/qwaylandwindow.cpp
@@ -1136,13 +1136,12 @@ void QWaylandWindow::handleUpdate()
mWaitingForFrameCallback = true;
mWaitingForUpdate = false;
- // Stop current frame timer if any, can't use killTimer directly, see comment above.
- int fcbId = mFrameCallbackTimerId.fetchAndStoreOrdered(-1);
- if (fcbId != -1)
- QMetaObject::invokeMethod(this, [this, fcbId] { killTimer(fcbId); }, Qt::QueuedConnection);
-
// Start a timer for handling the case when the compositor stops sending frame callbacks.
- QMetaObject::invokeMethod(this, [this] { // Again; can't do it directly
+ // Can't use killTimer directly, see comment above.
+ QMetaObject::invokeMethod(this, [this] {
+ int fcbId = mFrameCallbackTimerId.fetchAndStoreOrdered(-1);
+ if (fcbId != -1)
+ killTimer(fcbId);
if (mWaitingForFrameCallback)
mFrameCallbackTimerId = startTimer(100);
}, Qt::QueuedConnection);
--
2.25.1
|
