6bffeeed28
In order to reliably manage the reference count of the user data passed to page flip listeners - being the stage view - make the ownership of this data travel through the different objects that take responsibility of the next step. Initially this is the MetaKmsPageFlipListener that belongs to a MetaKmsUpdate. When a page flip is successfully queued, the ownership is transferred to a MetaKmsPageFlipClosure that is part of a MetaKmsPageFlipData. In the simple impl device, the MetaKmsPageFlipData is passed to drmModePageFlip(), then returned back via the DRM event. In the future atomic impl device, the MetaKmsPageFlipData is stored in a table, then retrieved when DRM event are handled. When the DRM events are handled, the page flip listener's interface callbacks are invoked, and after that, the user data is freed using the passed GDestroyNotify function, in the main context, the same as where the interface callbacks were called. When a page flip fails, the ownership is also transferred to a MetaKmsPageFlipClosure that is part of a MetaKmsPageFlipData. This page flip data will be passed to the main context via a callback, where it will discard the page flip, and free the user data using the provided GDestroyNotify. Note that this adds back a page flip listener type flag for telling the KMS implementation whether to actively discard a page flip via the interface, or just free the user data. Avoiding discarding via the interface is needed for the direct scanout case, where we immediately need to know the result in order to fall back to the composite pipeline if the direct scanout failed. We do in fact also need active discard via the interface paths, e.g. in the simple impl device when we're asynchronously retrying a page flip, so replace the ad-hoc discard paths in meta-renderer-native.c and replace them by not asking for no-discard page flip error handling. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1488> |
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.gitlab/issue_templates | ||
.gitlab-ci | ||
clutter | ||
cogl | ||
data | ||
doc | ||
meson | ||
po | ||
src | ||
subprojects | ||
tools | ||
.gitignore | ||
.gitlab-ci.yml | ||
config.h.meson | ||
COPYING | ||
meson_options.txt | ||
meson.build | ||
mutter.doap | ||
NEWS | ||
README.md |
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
The coding style used is primarily the GNU flavor of the GNOME coding style with some additions:
-
Use regular C types and
stdint.h
types instead of GLib fundamental types, except forgboolean
, andguint
/gulong
for GSource ids and signal handler ids. That means e.g.uint64_t
instead ofguint64
,int
instead ofgint
,unsigned int
instead ofguint
if unsignedness is of importance,uint8_t
instead ofguchar
, and so on. -
Try to to limit line length to 80 characters, although it's not a strict limit.
-
Usage of g_autofree and g_autoptr are encouraged. The style used is
g_autofree char *text = NULL;
g_autoptr (MetaSomeThing) thing = NULL;
text = g_strdup_printf ("The text: %d", a_number);
thing = g_object_new (META_TYPE_SOME_THING,
"text", text,
NULL);
thinger_use_thing (rocket, thing);
-
Declare variables at the top of the block they are used, but avoid non-trivial logic among variable declarations. Non-trivial logic can be getting a pointer that may be
NULL
, any kind of math, or anything that may have side effects. -
Instead of boolean arguments in functions, prefer enums or flags when they're more expressive.
-
Use
g_new0()
etc instead ofg_slice_new0()
. -
Initialize and assign floating point variables (i.e.
float
ordouble
) using the formfloating_point = 3.14159
orratio = 2.0
.
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.