Open LGUG2Z opened 1 month ago
I'm somewhat surprised that the OS doesn't do that for us. We use TerminateProcess
on exit to work around issues in WinUI (in particular on Windows 10). It's a simple and effective solution.
While I can see how we should try to emit these events on exit, I'm not sure whether that would help your project at all. A lot of applications, and not just Windows Terminal, use TerminateProcess
and I wonder if the same issue will happen if you kill a process with the task manager. Since TerminateProcess
is an entirely valid way to exit an application I'm not sure whether calling Windows Terminal buggy is fair.
But in any case, I suppose you'd need to make your window manager robust against sudden process exits independent of whether we address this issue or not.
Updates have already been made on our side to protect against any other applications which might exhibit this kind of non-standard WinEvent
behaviour in the future (referenced commit above).
I wonder if the same issue will happen if you kill a process with the task manager
I can confirm this is not the case; applications killed from the Task Manager send EVENT_OBJECT_DESTROY
.
A lot of applications, and not just Windows Terminal, use
TerminateProcess
komorebi
users are pretty quick and vocal to report issues like these, and with tens of thousands of users across a variety of professions using a breadth of both modern and legacy applications, Windows Terminal is the only application which has been reported to exhibit this behaviour.
If and when there are more examples from other applications I will be happy to share them, but for now, if 99% of other applications windows are doing the right thing (sending the appropriate WinEvent
when they are destroyed), I think it's worth trying to bring WT into conformance with the expected application behaviour in the Windows ecosystem.
I've hacked this C++ snippet together as a test case for this issue: https://gist.github.com/lhecker/82b029643e9f9ccf15304a623093880b
For any given application name, it records a set of HWNDs. They're added to the set on EVENT_OBJECT_CREATE
and removed on EVENT_OBJECT_DESTROY
. Currently, when opening/closing the window the counter for WindowsTerminal.exe will constantly increase.
However, I'm doing something wrong in that code, because the same thing happens for VS Code and other applications:
https://github.com/microsoft/terminal/assets/2256941/348d3489-c5ec-47bf-ac27-07bdd39d19fd
Since it happens with pretty much all applications, I must be doing something wrong but I can't figure out what. @LGUG2Z I don't mean to bother you unnecessarily, but if you can spot any flaws with what I described above, or any flaws in my code, please let me know. 🙂
Just after writing that comment, I finally figured out the first mistake I made! Apparently, when a EVENT_OBJECT_DESTROY
is received, OpenProcess
may not work anymore. In my first version I did an early return in that case.
I've now changed the code to instead search through all windows and that gets VS Code down to just 0 to 1 HWND leaks per launch. But that's the same amount as for Windows Terminal. Weird. Am I checking some of the callback parameters incorrectly? 🤔
Unfortunately I'm not well versed enough with CPP to offer much meaningful insight, but I created something similar using windows-rs
here: https://gist.github.com/LGUG2Z/da57d4f1fb294266e3793348b149fb79
[src\main.rs:126:5] state = {
"C:\\Windows\\explorer.exe": 3,
"C:\\Program Files\\WindowsApps\\Microsoft.WindowsTerminal_1.19.11213.0_x64__8wekyb3d8bbwe\\WindowsTerminal.exe": 2,
"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost.exe": 5,
}
I'm tracking the state in a hashmap keyed by the exe path, incrementing by 1 whenever a create event comes through, decrementing by 1 whenever a destroy event comes through, and removing from the map when we drop to 0.
For when OpenProcess calls might fail, there is another hashmap keyed with the HWND to look up the exe path if the API call fails.
With this I can see that there are a few lingering create events between opening and closing instances of WT that don't have corresponding destroy events, and I'm betting these are for the visible window that interaction happens with 🤔
Thoughts:
allowHeadless
, minimizeToNotificationArea
, and _quake
mode come to mindwe honestly don't know! We should find someone who does
Windows Terminal version
1.19.11213.0
Windows build number
10.0.22631.0
Other Software
No response
Steps to reproduce
Open a single instance of Windows terminal on the desktop. Close that instance of Windows Terminal.
EVENT_OBJECT_DESTROY
is not emitted.Expected Behavior
EVENT_OBJECT_DESTROY
should be emitted when the Windows Terminal window is closed by the window handle that the user has just interacted with.Actual Behavior
EVENT_OBJECT_DESTROY
is not emitted for the Windows Terminal window that was closed.When opening Windows Terminal,
EVENT_SYSTEM_FOREGROUND
is emitted, and the window handle of the actual window that I as the user interact with is the log example below is658858
:When I close the window, sometimes an
EVENT_OBJECT_HIDE
is emitted, but it is emitted for a completely separate window handle (920252
):