ENH: Add process_name key to support broken/missing _NET_WM_PID

[novahahn]

I tried to configure XSuspender for Steam:

[Steam]
match_wm_class_contains = Steam

This had no effect: XSuspender added and removed the main window to and from the suspension queue ("Suspending window in 5s: 0xa20002b (0): Steam/Removing window 0xa20002b (0) from suspension queue: Steam", but did not actually send any signals. I tried adding

exec_suspend = pkill -STOP steam
exec_resume = pkill -CONT steam

but these were not executed until I also added send_signals = false. But then, XSuspender also suspended Steam when I the settings window.

Using this patch, I'm currently testing the config

[Steam]
match_wm_class_contains = Steam
suspend_subtree_pattern = steam
process_name = steam
exec_suspend = ! pgrep -lf 'reaper SteamLaunch AppId' # Running games don't like it when Steam is suspended

which seems to work.

---

Although I don't use Flatpak for it, Steam does not set _NET_WM_PID at all. It uses multiple processes, but they all belong to a single subtree.

[novahahn]

I don't know the package name(s) for RPM distros

[kernc]

Can you describe in a few words what issue this is fixing for you and how you use it?

Thanks!

[kernc]

Should in fact mention this matches cmdlines, so I wonder if we couldn't have a better expressed name, such as process_cmdline_matches?

[kernc]

And then need to explain this is being matched as literal strings.

[novahahn]

I don't like process_cmdline_matches since we don't match on the entire cmdline. How about program_basename_matches? That is what htop calls it.

[kernc]

we don't match on the entire cmdline

I missed that. Wouldn't it be more versatile to match full cmdlines? process_... in either case, probably.

[novahahn]

I don't think there's a good way to match on the full cmdline. Contains matchers would be too broad. Prefix and exact matchers would be too cumbersome. I don't think being able to match on the path to the executable is worth it. Regex could work, but I think that would be error-prone especially when paths contain spaces.

Matching on the process name + args would however be an improvement, I think.

[kernc]

I'm still most readily waiting for your use case example! E.g. "while running Flatpak app Foo, it happens that ..." What are the set PIDs, process cmdlines, process tree? As the reader of this bug report/PR, I'd naturally like to see and understand the broken setup, without needing to investigate everything from the absolute beginning.

[novahahn]

OK. I thought the implicit "use XSuspender when _NET_WM_PID is broken or missing" was sufficient :)