The connection was stored by the Port where it was initiated from:
1. Connect A to B
2. Disconnect B from A
(1) Port A remembers the connection to B
(2) Port B does not know about the connection from A
Since disconnect is initiated on port B, port A still retained
the connection information.
When restarting the engine, Port::reconnect() reestablished the
connection.
This is only relevant when libardour's own connection information is
used. e.g. the session is closed without engine, or when re-starting
the engine while the session is open.
Changes include workarounds for weird Rubberband API (pad, drop, truncate requirements),
and a shift to push logic after a slot is finished back up into the TriggerBox.
Not finished yet, some easily encountered bugs remain
::snap_to() was intended to round a Beats value to the nearest multiple
of another Beats value. It did not do that, but instead rounded down.
Worse, it used Beats::operator/ which in turn uses int_div_round(),
which is incorrect for a situation where we need integer truncation.
The changes fix the actual arithmetic and add 2 variant functions so that the
API includes round down, round up and round to nearest.
max_samplepos and max_samplecnt and both INT64_MAX which is (a) too large to fit into a signed 62 bit
integer and (b) definitely too large to be represented in a signed 62 bit superclock value.
Move the constructors that use samplepos_t into the .cc file, and treat these two values as special
cases that mean "as large/late/huge/long as possible".
This works around a race-condition, calling d'tors from
two threads concurrently.
The GUI thread destroys ctrl surfaces. ~~MIDIControllable()
calls ::drop_external_control() -> ::midi_forget()
This unsubscribes from signals (notably MIDI::Parser events)
by calling ScopedConnection::disconnect(), Connection::disconnect().
At the same time auto_connect_thread can call
PortManager::clear_pending_port_deletions() which removes
the MIDI port and destorys the MIDI::Parser.
~Parser() calls Connection::signal_going_away() to invalidate
connected signals.
This can deadlock if it is called concurrently with
Connection::disconnect() on the same signal.
see also
https://discourse.ardour.org/t/ardour-session-close-hangs/106523/10
