CoreMIDI ports are dynamic. When dis/connecting a device CoreAudio's
AudioHardware-PropertyListener triggers a callback which can
add/remove ports.
This can not happen concurrently with processing, but it may happen
concurrently with a user creating tracks using Ardour's UI
and/or session-load/setup.
Don't call ::set_value() if the actual value has not changed.
e.g. MIDI-CC or integer controls. Moving the Bar-controller was able to
create events even though the actual value remained unchanged.
This check has to be done UI-side, since the underlying API is also used
for state-restore and automation. e.g.
"old value" (user-set) may be default "0", "new value" may also be "0" but
libardour still needs to send an event (a synth's internal state may not
default to "0")
Drag a group-tab's right-edge horizontally to the right to remove all
current routes from the groups before adding new routes to the group.
The group becomes temporarily empty, and
Session::route_removed_from_route_group() removes the group (before new
routes can be added).
* Detach model from treeview and disable sorting during refill.
* Prevent multiple re-fills due to sensitivity updates of ComboBoxes:
gtk_widget_set_sensitive() -> CairoWidget::on_state_changed ()
-> CairoWidget::set_visual_state () -> StateChanged Signal
The Script-selector is used in various places, not just for
Action-scripts.
Also add a "--" prefix for the separator to avoid name conflicts with
actual script names.
Empirically this decreases gc-spike duration (worst-case) by a factor of
two and speeds up the average gc-run by a factor of over 4 (depending
on the amount of memory used by the plugin).
Add custom API to prevent Lua Objects from being garbage collected.
This is intended to for Ardour LuaBridge bindings (~1MB Objects:
tables, functions and userdata).
The bindings are persistent and the gc can skip them in mark & sweep
phases. This is a significant performance improvement for garbage
collection.
Note. The next version of Lua (5.4) will come with a generational-gc
rather than an incremental, so extending the API at this point in time
is acceptable.
