They're a dime a dozen. If it gets called exclusively from the
input thread, it got one. Hopefully these breadcrumbs will be
enough so people don't lose their way here.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
This (now) doesn't change anything in regards to the API that the UI
thread should access from the MetaSeatImpl. The MetaInputDeviceNative,
MetaInputSettings and MetaKeymap objects are now considered owned by
the input thread, as well as all of libinput objects.
The MetaEventSource now dispatches events in a GMainContext that is
the thread default to this thread, and all UI-thread-accessible API
(seat and virtual input device API) will be handled in a serialized
manner by that same input thread.
The MetaSeatImpl itself is still considered to be owned by the caller
thread, and all the signals that this object emits will be emitted in
the GMainContext that is default at the time of calling
meta_seat_impl_new().
The MetaInputSettings configuration changes will likewise be handled
in the input thread, close to libinput devices.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Instead of going through the event queue, stage handling code, and
back to the input device via a vmethod call, do this directly in the
MetaSeatImpl. This is not too different from X11, where everything
happens inside the backend.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
This API is the one accessed from different bits of the UI thread,
make it "async" (it's basically one-way setters, so API stays the same
in the surface) and able to run in the MetaSeatImpl main context.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Simplify the handling of numlock state, so it can be entirely handled
within the input thread. Since the saving/restoring is triggered inside
each backend code, there's no need anymore for meta_backend_set_numlock().
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Push it a little bit down to the MetaSeatNative. As both the UI thread
and the input thread are interested in dealing with the xkb_keymap and
it is not meant to be used in different threads, keep 2 separate copies
around.
The keyboard map will always be set from the UI thread, so the xkb_keymap
owned by the MetaSeatNative (owned by the UI thread) can be considered
canonical.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Don't let the vfuncs (meant to be called from the UI thread) deal with
xkb state itself. Instead store the current state in struct fields, which
is then fetched in vfuncs.
This makes the keymap able to be used from the UI thread, while being
maintained by the input thread. Same caveats apply than
clutter_seat_query_state(), you are asking for the most up-to-date state,
but it still may be changing under your feet.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Wrap all keyboard state updates, and all pointer/stylus/touch cursor
position with a write lock, and ::query_state() (The only entrypoint
to this state from other threads) with a read lock.
The principle is that query_state may be called from different threads
(UI so far, but maybe KMS too in the future), while the input thread
may (or may not) be updating it. This state is fetched "atomically"
(eg. x/y will be consistently old or new, if the input thread were
updating it at the same time).
There's other places deep in backends/native that read this state,
they all will run in the input thread, so they count as "other readers"
to the other thread. Those changes are already mutually exclusive with
updates, so they don't explicitly need the RW lock.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Depending on the backend, we want to integrate this object at different
levels. It will sit close to the MetaBackendX11/MetaSeatX11 in X11, but
it will be put deep down with MetaSeatImpl in the native backend, in a
separate thread.
Since we can't depend on a single object type, nor are able to track
ClutterSeat signals neatly, make this API something to be called
explicitly by backends.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
These changes will happen in the input event management code, so let them
be emitted via the MetaSeatImpl, as that's what we'll have neat access to.
The ClutterSeat signals are now emitted from there.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Move most of the functional bits (those meant to run on a standalone
thread) to a MetaSeatImpl object. This object is managed by the MetaSeatImpl
and not exposed outside the friend MetaSeatNative/MetaInputDeviceNative/
MetaInputSettings classes.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
