There is no longer an extra set of rt-threads, but existing
process-graph threads are reused.
There are two main benefits to this approach: graph-threads
have a SessioEvent pool and ProcessThread buffers. They are
also joined to work-groups (on macOS), or JACK created threads
(cgroups).
The process-graph trigger_queue only needs to call
::prep() and ::run() without knowing any further details.
This is in preparation for using the graph-threads for rt-tasks
Route::silence() runs plugins. With a heavy session
that relies on multi-core processing, sending silence
to processors will have to be done in parallel.
Otherwise it can result in large DSP load and xruns.
This may allow to revert b3497b3f8f, which was
a prior attempt to resolve this, before understanding
the actual cause.
When auditioning, ardour's process_audition calls Route::silence
for all routes. PluginInsert::silence simply fed all [ports of all
[replicated] plugins with silence, regardless of port-mapping.
This can cause some VST2/3 plugins to change state, and enable ports
(e.g. stereo VST2 plugins on mono tracks), causing glitches.
This commit is mainly intended to investigate how significant
this glitch is when starting to audition.
* don't create a new MixerScene if one already exists
* only resize the vector when necessary
* adding a new scene at position N should not shrink the vector size
Previously it was possible to cause a 64bit signed to 32bit
unsigned overflow. `from_stretcher` is pframes_t aka. uint32_t.
With int64_t arguments a std::min() expression producing negative
result will result in large 32bit values:
(pframes_t) std::min<int64_t>(1024, 176400 - 187392) = 4294956304
This produced a segfault when used as n_samples to copy in
buf.accumulate_from()
Because a bartime point IS-A tempo point and IS-A meter point, we cannot just delete the tempo
point passed into core_add_tempo() if the new point replaces an existing one. Ditto for meter.
So, leave that logic up to the caller
timecnt_t and timepos_t constructors with the initial argument as an int64_t
are assumed to be using samples. We need to use the explicit factory methods
instead.
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.
No behavior should be changed by this modification; the argument has a default value of false, which
matches previous semantics, and every instance where the argument is specified, it is given as false.
This uses boost::multiprecision::int512_t when multiplying and dividing by the numerator
and denominator of a ratio_t. 128 bits would be sufficient but for some reason, the boost
docs show the 512 bit variant being very slightly faster.
This is a better solution than using a double, which although it will prevent overflow
has fairly limited resolution.
