0c55e87d8f
When calculating regions, a lot of temporary allocations are created. For
the array of rects (which is often a short number of them) we can use
stack allocations up to 1 page (256 cairo_rectangle_int_t). For building
a region of rectangles, cairo and pixman are much faster if you have all
of the rectangles up front or else it mallocs quite a bit of temporary
memory.
If we re-use the cairo_rectangle_int_t array we've already allocated (and
preferably on the stack), we can delay the creation of regions until after
the tight loop.
Additionally, it requires fewer allocations to union two cairo_region_t
than to incrementally union the rectangles into the region.
Before (percentages are of total number of allocations)
TOTAL FUNCTION
[ 100.00%] [Everything]
[ 100.00%] [gnome-shell --wayland --display-server]
[ 99.67%] _start
[ 99.67%] __libc_start_main
[ 99.67%] main
[ 98.60%] meta_run
[ 96.90%] g_main_loop_run
[ 96.90%] g_main_context_iterate.isra.0
[ 96.90%] g_main_context_dispatch
[ 90.27%] clutter_clock_dispatch
[ 86.54%] _clutter_stage_do_update
[ 85.00%] clutter_stage_cogl_redraw
[ 84.98%] clutter_stage_cogl_redraw_view
[ 81.09%] cairo_region_union_rectangle
After (overhead has much dropped)
TOTAL FUNCTION
[ 100.00%] [Everything]
[ 99.80%] [gnome-shell --wayland --display-server]
[ 99.48%] _start
[ 99.48%] __libc_start_main
[ 99.48%] main
[ 92.37%] meta_run
[ 81.49%] g_main_loop_run
[ 81.49%] g_main_context_iterate.isra.0
[ 81.43%] g_main_context_dispatch
[ 39.40%] clutter_clock_dispatch
[ 26.93%] _clutter_stage_do_update
[ 25.80%] clutter_stage_cogl_redraw
[ 25.60%] clutter_stage_cogl_redraw_view
https://gitlab.gnome.org/GNOME/mutter/merge_requests/1071
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||
|---|---|---|
| .gitlab/issue_templates | ||
| .gitlab-ci | ||
| clutter | ||
| cogl | ||
| data | ||
| doc | ||
| meson | ||
| po | ||
| src | ||
| 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.
The coding style used is primarily the GNU flavor of the GNOME coding
style
with some minor additions such as preferring stdint.h types over GLib
fundamental types, and a soft 80 character line limit. However, in general,
look at the file you're editing for inspiration.
Commit messages should follow the GNOME commit message guidelines. We require an URL to either an issue or a merge request in each commit.
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.