Delaylines are not saved in the XML and internal-return is an
invisible processor not explicitly re-added when the state is restored.
They are [re]inserted during Route::setup_invisible_processors().
So this method need to be called after restoring processor state
(indirectly via configure_processors_unlocked as needed).
PS. During route creation this call happens explicitly and on session load
hookup_io() -> Route::output_change_handler() implicitly sets this up.
Speed up route creation: add_processor() takes a process-lock
and calls configure_processors() but this is done explicitly at the
end of init() already.
This fixes a bug on some modern mac systems. Related to
setup_logging() changing stderr to use ASL and write to com.apple.console.
When a forked application writes to stderr while ASL is used,
the child is terminated for some reason.
Route::processors_changed() signal connects to a same thread session-slot
Session::route_processors_changed() which can end up iterating over
Routes and Processors to re-calculate latency.
This takes a ReadLock after WriteLock, which eventually leads a duplicate
unlock and segfault.
This fixes various MS related action sensitivity issues, as well
as action-states.
Also manually adding a monitor-section to a session now always
immediately shows it, regardless of prior ToggleMonitorSection
visibility.
This partially reverts 639dff3a7c. When loading a session,
the monitor-bus that was saved with the session is used.
This changes semantics of the monitor-section/config.
Config::set_use_monitor_bus(bool) is used to initiate a change!
Notification about the change is sent asynchronously by
Session::MonitorBusAddedOrRemoved
It is no longer possible to directly call add/remove_monitor_section()
and leave the session + config in an inconsistent state.
