Revert this once transport state machine waits for de-click!
This causes audible-clicks on stop, but prevents audible artifacts
on LocateRoll with the current transport-control-logic.
During session load, all earlier configure_processors() calls
were useless and not taking I/O into account! The Delivery ::pan_out()
needs _output I/O ports in order to correctly report the correct
port-count!
This worked in earlier versions because Config->map_parameters()
triggered [two] processor re-configs via ::listen_position_changed().
That behavior was changed in 1af123465c
This is more useful than exact_equivalent() since _start offset
may not match in some cases (compounds, import, record with different
capture latencies).
However shared group editing (range, copy/paste) does result in
consistent layers and matching position+length.
Listen positions are already correctly set when the route state
is restored. The Route directly uses the Config.
This skips duplicate calls to re-configure all processors on all Routes
during RCConfiguration::map_parameters() on session-load, twice
(pfl-position, listen-position)
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.
