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Jonas Ådahl 6bffeeed28 kms/page-flip: Pass ownership of listener user data along with closure
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>
2021-01-22 16:47:08 +00:00
.gitlab/issue_templates gitlab: Add missing < in markdown comment tag 2020-02-14 03:10:28 +00:00
.gitlab-ci ci: Replace custom commit-log script with ci-fairy 2021-01-11 14:02:58 +01:00
clutter cursor-renderer/native: Update HW state during frames 2021-01-22 16:47:08 +00:00
cogl kms: Add symbolic page flips and cogl frame infos 2021-01-22 16:47:08 +00:00
data xwayland: Enable Xwayland on demand by default 2021-01-19 09:33:33 +01:00
doc Add MetaGravity and replace X11 equivalent with it 2020-02-29 21:01:50 +00:00
meson build: Add postinstall script 2019-08-27 09:57:54 +00:00
po Update Portuguese translation 2021-01-20 11:50:55 +00:00
src kms/page-flip: Pass ownership of listener user data along with closure 2021-01-22 16:47:08 +00:00
subprojects build: bump ABI to sysprof-capture-4 2020-07-28 11:13:30 -07:00
tools tools: Remove obsolete ppa-magic.py 2018-11-30 11:12:12 +08:00
.gitignore build: bump ABI to sysprof-capture-4 2020-07-28 11:13:30 -07:00
.gitlab-ci.yml build: Bump gsettings-desktop-schemas dependency 2021-01-14 13:58:16 +00:00
config.h.meson xwayland: Check for listenfd option 2021-01-22 11:40:30 +01:00
COPYING
meson_options.txt xwayland: Check X11 clients prior to terminate Xwayland 2021-01-18 17:52:22 +01:00
meson.build xwayland: Check for listenfd option 2021-01-22 11:40:30 +01:00
mutter.doap mutter.doap: Add marge-bot as a maintainer 2020-11-16 11:59:45 +01:00
NEWS Tag release 40.alpha.1.1 2021-01-14 17:22:43 +01:00
README.md README: Elaborate coding style and commit message guidelines 2020-10-28 07:28:55 +00:00

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 for gboolean, and guint/gulong for GSource ids and signal handler ids. That means e.g. uint64_t instead of guint64, int instead of gint, unsigned int instead of guint if unsignedness is of importance, uint8_t instead of guchar, 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 of g_slice_new0().

  • Initialize and assign floating point variables (i.e. float or double) using the form floating_point = 3.14159 or ratio = 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.