24083e1e58
clutter_stage_schedule_update() sets the field `update_scheduled` to
`TRUE` as an optimization to make redundant updates a no-op. This failed
if there was a pending event and if the stage was not yet mapped.
What happened is:
* clutter_stage_schedule_update() is called
- ClutterStage::update_scheduled is set to TRUE
- frame clock scheduled
* frame clock dispatches
- frame is discarded early, no actual stage update happens
* device is created (e.g. virtual device from remote desktop session)
- `device-added` event reaches ClutterStage::event_queue
* stage is shown
- clutter_stage_schedule_update() is called
- ClutterStage::update_scheduled is TRUE
- ClutterStage::event_queue has events in it
- These two conditions means clutter_schedule_update() becomes a
no-op
At this point, no more updates will happen from
clutter_stage_schedule_update().
Fix this by resetting `ClutterStage::update_scheduled` to `FALSE` even
if the frame was discarded due to the stage not yet being mapped.
A test case is added that replicates the above descibed events.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3804
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4152>
Mutter
Mutter is a Wayland display server and X11 window manager and compositor library.
When used as a Wayland display server, it runs on top of KMS and libinput. It implements the compositor side of the Wayland core protocol as well as various protocol extensions. It also has functionality related to running X11 applications using Xwayland.
When used on top of Xorg it acts as a X11 window manager and compositing manager.
It contains functionality related to, among other things, window management, window compositing, focus tracking, workspace management, keybindings and monitor configuration.
Internally it uses a fork of Cogl, a hardware acceleration abstraction library used to simplify usage of OpenGL pipelines, as well as a fork of Clutter, a scene graph and user interface toolkit.
Mutter is used by, for example, GNOME Shell, the GNOME core user interface, and by Gala, elementary OS's window manager. It can also be run standalone, using the command "mutter", but just running plain mutter is only intended for debugging purposes.
Contributing
To contribute, open merge requests at https://gitlab.gnome.org/GNOME/mutter.
It can be useful to first look at the GNOME Handbook and the documentation and API references below first.
Documentation
- Coding style and conventions
- Git conventions
- Code overview
- Building and Running
- Debugging
- Monitor configuration
API Reference
- Meta: https://mutter.gnome.org/meta/
- Clutter: https://mutter.gnome.org/clutter/
- Cogl: https://mutter.gnome.org/cogl/
- Mtk: https://mutter.gnome.org/mtk/
Meetings
There are recurring meetings to discuss development of GNOME Shell, mutter and related components.
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.