1d7920872d
When drmModePageFlip() or drmModeAtomicCommit() unexpectedly failed (e.g. ENOSPC, which has been seen in the wild), this failure was not handled very gracefully. The page flip listener for the scanout was left in the MetaKmsUpdate, meaning when the primary plane composition was later page flipped, two page flip listeners were added, one for the primary plane, and one for the scanout. This caused the 'page-flipped' event to be handled twice, the second time being fatal. Handle this by making 'no-discard' listener flag be somewhat reversed, and say 'drop-on-error', and then drop all 'drop-on-error' listeners when a MetaKmsUpdate failed to be processed. Also for a "preserve" flagged update, don't ever trigger "discard" callbacks just yet, as preserved updates are used again for the primary plane composition, in order to not miss e.g. CRTC gamma updates, or cursor plane updates, which were added separately. Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1809 Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1910>
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 af 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 look at the documentation available at the Wiki.
Coding style and conventions
See HACKING.md.
Git messages
Commit messages should follow the GNOME commit message
guidelines. We require an URL
to either an issue or a merge request in each commit. Try to always prefix
commit subjects with a relevant topic, such as compositor: or
clutter/actor:, and it's always better to write too much in the commit
message body than too little.
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.