05efcb4b21
Move the use count from a separate MetaWaylandBufferRef struct to the MetaWaylandBuffer class, and remove the former. The buffer use count is now incremented already in meta_wayland_surface_commit, since the Wayland protocol defines the buffer to be in use by the compositor at that point. If the buffer attachment ends up being dropped again before it is applied to the surface state (e.g. because another buffer is committed to a synchronized sub-surface before the parent surface is committed), the use count is now decremented, and a buffer release event is sent if the use count drops to 0. Buffer release events were previously incorrectly not sent under these circumstances. Test case: Run the weston-subsurfaces demo with the -r1 and/or -t1 command line parameter. Resize the window. Before this change, weston-subsurfaces would freeze or abort after a few resize operations, because mutter failed to send release events and the client ran out of usable buffers. v2: * Handle NULL priv->buffer_ref in meta_wayland_cursor_surface_apply_state. v3: * Remove MetaWaylandBufferRef altogether, move the use count tracking to MetaWaylandBuffer itself. Much simpler, and doesn't run into lifetime issues when mutter shuts down. v4: * Warn if use count isn't 0 in meta_wayland_buffer_finalize. * Keep pending_buffer_resource_destroyed for attached but not yet committed buffers. If the client attaches a buffer and then destroys it before commit, we ignore the buffer attachement, same as before this MR. v5: * Rebase on top of new commit which splits up surface->texture. * MetaWaylandSurfaceState::buffer can only be non-NULL if ::newly_attached is TRUE, simplify accordingly. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1880>
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 look at the documentation available at the Wiki.
The API documentation is available at:
- Meta: https://gnome.pages.gitlab.gnome.org/mutter/meta/
- Clutter: https://gnome.pages.gitlab.gnome.org/mutter/clutter/
- Cally: https://gnome.pages.gitlab.gnome.org/mutter/cally/
- Cogl: https://gnome.pages.gitlab.gnome.org/mutter/cogl/
- CoglPango: https://gnome.pages.gitlab.gnome.org/mutter/cogl-pango/
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.
Default branch
The default development branch is main. If you still have a local
checkout under the old name, use:
git checkout master
git branch -m master main
git fetch
git branch --unset-upstream
git branch -u origin/main
git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.