This happened initially during session load.
The GUI thread performed a direct refill (blocking wait)
`Session::post_engine_init() -> Track::seek() -> DiskReader::seek() -> DiskReader::do_refill_with_alloc()`
while concurrently the butler thread does the same:
```
Session::butler_transport_work() -> Track::non_realtime_locate() -> Route::non_realtime_locate()
-> DiskIOProcessor::non_realtime_locate() -> DiskReader::seek() -> DiskReader::do_refill_with_alloc()
-> DiskReader::refill_audio()
```
We do not want the GUI to wait, so now we just request a locate
and let refill happen in the background.
When an archive are saved, a new folder in interchange/ is created,
named after the archive. However session-archive also retains files
in the session-folder that Ardour does not know about.
This can cause that the the original interchange folder is retained.
It will be empty with just the .DS_Store file in it. The result is
that the session may not load if there is an ambiguity.
This workaround bypasses RegionMap and SessionPlaylist APIs
(region_use_count, destroy_region) which are not directly
applicable to Triggerboxes. There are likely various edge
cases until TriggerBoxes integrate with Session Playlist.
e.g. whole file regions generated for regions/source used by
triggerboxes are cleaned up.
A compound region itself may be unused, but the nested source
it provides can be used in another region compound.
In this case the first, unused, region needs to be saved
to save the nested source.
Note that ::find_all_sources_across_snapshots() finds and retains
all sources in the SourceList of other snapshots regardless
if they are used in those snapshots.
Session handles the case when the button is used to enable cue triggering, by
forcing a locate to the current transport position.
TriggerBox now connects to the correct configuration object to notice when cue
triggering is disabled, and sets _cancel_locate_armed appropriately.
libs/ardour/session_state.cc:1500:13: note: in instantiation of
function template specialization 'XMLNode::set_property<unsigned long>'
requested here
libs/pbd/pbd/string_convert.h:151:11: error:
type 'unsigned long' cannot be used prior to '::' because it
has no members
This commit leaves two issues outstanding:
1. unclear/ugly semantics for drag operations that reset the GUI thread's tempo map to the writable copy
2. undo/redo for the tempo map
These will be addressed in future commits
This allows two reader threads to proceed without blocking each other, as can
happen when the butler renders a MIDI track into an RT-safe buffer while the
GUI reads the same MidiModel/Source for visual display.
When loading a session, we now just set up port state, which will
populate the Port::_connections member, and then once all ports have
been created, use PortManager::reconnect_ports() to get everything connected.
"While 'atomic' has a volatile qualifier, this is a historical
artifact and the pointer passed to it should not be volatile."
Furthermore "It is very important that all accesses to a
particular integer or pointer be performed using only this API"
(from https://developer.gnome.org/glib/2.68/glib-Atomic-Operations.html)
Hence initialization of atomic variables is changed to also use
this API, instead of directly initializing the value.
This also fixes a few cases where atomic variables were
accessed directly.
see also libs/pbd/pbd/g_atomic_compat.h
By default Apple uses a private TMP folder. While mktemp
returns "/tmp/xxx" the canonical path is "/private/tmp/xxx".
This lead to issues when tmp-prefix is removed when building
the session-archive.
See also e52bdc55ad
