It is important that we end plasma-core.target plasma-workspace.target
and graphical-session.target when we log out. graphical-session in turn
closes all other apps and daemons and prevents restarts.
Handling it in systemd gives the least racey option.
graphical-session used to be hanlded in the plasma-ksmserver service
file, but this was removed in 5.24 in a refactor where it caused issues
for Xwayland restarting.
This patch reintroduces the sentinel programs to close down our target,
which in turn take down the other targets. It also removes a complicated
use of templates that in hindsight didn't really solve anything.
BUG: 448492
Testing done:
- logout of wayland shows all targets as inactive, logging in
repeatedly works smoothly
- logout of X11 behaves the same.
- calling systemctl --user stop plasma-kwin_wayland.service closes the
session
- killing ksmserver on wayland does not close the session
- killing ksmserver on X does
If invoked on gnome we should always return success
this is because a desktop file that has X-KDE-AutostartCondition
probably has an X-Gnome- equivalent and we only want one to run
this would match non systemd behaviour.
See also: https://github.com/systemd/systemd/pull/22115
Currently we have a whole daisy-chain of startplasmawayland-> kwin ->
startplasmawaylandsession -> launching the session.
This was needed as we needed environment variables which previously we
only knew after kwin started.
After some kwin refactoring this is no longer the case, and
kwin_wayland_wrapper will sync it's environment variables to the
appropriate startup environments.
This allows us to move starting kwin_wayland to be systemd managed,
brining resource control, alongside it's classic counterpart
plasma-session.
Systemd passes the condition as `--condition <cond>`, not as a positional argument.
Also switch around return codes, 255 is special-cased to mean that the unit has failed.
Plasma core is moved away from being a template. This makes it easier
for others to mark themselves as being after. A new readme is added to
explain the design.
This means on logout we'll be gracefully closed down.
All of these are closing down properly anyway, but this makes things a
bit more explicit in case you managed to log out at an awkward point.
Summary:
This brings numerous advantages such as:
- easier admin configuration with drop-ins, overrides and multiple
hooks throughout (and only having to learn one tool)
- session cleanup on exit, avoiding that occasional part where shutdown
hangs
- startup that actually knows when things are up
- race free autostart and DBus activation at once
- logs that rotate are split by service and usable
- resource management through slices and cgroups (the part I want)
Over the past 2 years I've been trying to tidy up and encapsulate the
relevant parts of startup into the binary plasma-session so that we can
just runtime swap out that one part and supporting both paths will be
easy.
Support is toggleable via cmake flag, as it seems like it should be a
distro decision, especially as we will require a specific systemd with
the xdg-generator.
KDED/kwin/other services are attached to the relevant repo.
Task T11914
Differential Revision: https://phabricator.kde.org/D28305
squash
David Edmundson
Laurent Montel
David Redondo
Alexander Lohnau
S Page
Henri Chain
Gabriel Souza Franco