libardour: use Processor::check_active() in all Processors instead of per-processor code

There are a few exceptions where the semantics make this too complex to be worth forcing check_active()

libs/ardour/amp.cc

@@ -82,7 +82,7 @@ scale_midi_velocity(Evoral::Event<MidiBuffer::TimeType>& ev, float factor)
 void
 Amp::run (BufferSet& bufs, samplepos_t /*start_sample*/, samplepos_t /*end_sample*/, double /*speed*/, pframes_t nframes, bool)
 {
-	if (!_active && !_pending_active) {
+	if (!check_active()) {
 		/* disregard potentially prepared gain-automation. */
 		_apply_gain_automation = false;
 		return;
@@ -155,8 +155,6 @@ Amp::run (BufferSet& bufs, samplepos_t /*start_sample*/, samplepos_t /*end_sampl
 			_current_gain = target_gain;
 		}
 	}
-
-	_active = _pending_active;
 }
 
 gain_t

libs/ardour/delivery.cc

@@ -241,16 +241,16 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 {
 	assert (_output);
 
+	if (!check_active()) {
+		_output->silence (nframes);
+		return;
+	}
+
 	PortSet& ports (_output->ports());
 	gain_t tgain;
 
 	if (ports.num_ports () == 0) {
-		goto out;
-	}
-
-	if (!_active && !_pending_active) {
-		_output->silence (nframes);
-		goto out;
+		return;
 	}
 
 	/* this setup is not just for our purposes, but for anything that comes after us in the
@@ -283,7 +283,7 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 			bufs.set_count (output_buffers().count ());
 			Amp::apply_simple_gain (bufs, nframes, GAIN_COEFF_ZERO);
 		}
-		goto out;
+		return;
 
 	} else if (tgain != GAIN_COEFF_UNITY) {
 
@@ -353,9 +353,6 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 			}
 		}
 	}
-
-out:
-	_active = _pending_active;
 }
 
 XMLNode&

libs/ardour/disk_reader.cc

@@ -277,17 +277,8 @@ DiskReader::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
 	const bool                     midi_only = (c->empty() || !_playlists[DataType::AUDIO]);
 	bool                           no_disk_output = g_atomic_int_get (&_no_disk_output) != 0;
 
-	if (_active) {
-		if (!_pending_active) {
-			_active = false;
-			return;
-		}
-	} else {
-		if (_pending_active) {
-			_active = true;
-		} else {
-			return;
-		}
+	if (!check_active()) {
+		return;
 	}
 
 	const gain_t target_gain = ((speed == 0.0) || ((ms & MonitoringDisk) == 0)) ? 0.0 : 1.0;

libs/ardour/disk_writer.cc

@@ -423,11 +423,10 @@ void
 DiskWriter::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample,
                  double speed, pframes_t nframes, bool result_required)
 {
-	if (!_active && !_pending_active) {
+	if (!check_active()) {
 		_xrun_flag = false;
 		return;
 	}
-	_active = _pending_active;
 
 	uint32_t n;
 	boost::shared_ptr<ChannelList> c = channels.reader();

libs/ardour/internal_return.cc

@@ -37,10 +37,9 @@ InternalReturn::InternalReturn (Session& s, Temporal::TimeDomain td, std::string
 void
 InternalReturn::run (BufferSet& bufs, samplepos_t /*start_sample*/, samplepos_t /*end_sample*/, double /*speed*/, pframes_t nframes, bool)
 {
-	if (!_active && !_pending_active) {
+	if (!check_active()) {
 		return;
 	}
-	_active = _pending_active;
 
 	Glib::Threads::Mutex::Lock lm (_sends_mutex, Glib::Threads::TRY_LOCK);
 

libs/ardour/internal_send.cc

@@ -211,7 +211,7 @@ InternalSend::send_to_going_away ()
 void
 InternalSend::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, double speed, pframes_t nframes, bool)
 {
-	if ((!_active && !_pending_active) || !_send_to) {
+	if (!check_active() || !_send_to) {
 		_meter->reset ();
 		return;
 	}
@@ -314,7 +314,7 @@ InternalSend::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sa
 		/* we were quiet last time, and we're still supposed to be quiet. */
 		_meter->reset ();
 		Amp::apply_simple_gain (mixbufs, nframes, GAIN_COEFF_ZERO);
-		goto out;
+		return;
 	} else if (tgain != GAIN_COEFF_UNITY) {
 		/* target gain has not changed, but is not zero or unity */
 		Amp::apply_simple_gain (mixbufs, nframes, tgain);
@@ -339,9 +339,6 @@ InternalSend::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sa
 	_thru_delay->run (bufs, start_sample, end_sample, speed, nframes, true);
 
 	/* target will pick up our output when it is ready */
-
-out:
-	_active = _pending_active;
 }
 
 void

libs/ardour/meter.cc

@@ -92,7 +92,7 @@ PeakMeter::display_name () const
 void
 PeakMeter::run (BufferSet& bufs, samplepos_t /*start_sample*/, samplepos_t /*end_sample*/, double /*speed*/, pframes_t nframes, bool)
 {
-	if (!_active && !_pending_active) {
+	if (!check_active()) {
 		return;
 	}
 
@@ -196,8 +196,6 @@ PeakMeter::run (BufferSet& bufs, samplepos_t /*start_sample*/, samplepos_t /*end
 	if (_bufcnt > zoh) {
 		_bufcnt = 0;
 	}
-
-	_active = _pending_active;
 }
 
 void

libs/ardour/plugin_insert.cc

@@ -1254,7 +1254,7 @@ PluginInsert::silence (samplecnt_t nframes, samplepos_t start_sample)
 {
 	automation_run (start_sample, nframes, true); // evaluate automation only
 
-	if (!active ()) {
+	if (!check_active()) {
 		// XXX delaybuffers need to be offset by nframes
 		return;
 	}
@@ -1328,8 +1328,6 @@ PluginInsert::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sa
 		_delaybuffers.flush ();
 	}
 
-	_active = _pending_active;
-
 	/* we have no idea whether the plugin generated silence or not, so mark
 	 * all buffers appropriately.
 	 */

libs/ardour/polarity_processor.cc

@@ -57,15 +57,16 @@ void
 PolarityProcessor::run (BufferSet& bufs, samplepos_t /*start_sample*/, samplepos_t /*end_sample*/, double /*speed*/, pframes_t nframes, bool)
 {
 	size_t chn = 0;
+
 	assert (bufs.count().n_audio () <= _current_gain.size());
-	if (!_active && !_pending_active) {
+
+	if (!check_active()) {
 		/* fade all to unity */
 		for (BufferSet::audio_iterator i = bufs.audio_begin(); i != bufs.audio_end(); ++i, ++chn) {
 			_current_gain[chn] = Amp::apply_gain (*i, _session.nominal_sample_rate(), nframes, _current_gain[chn], 1.0);
 		}
 		return;
 	}
-	_active = _pending_active;
 
 	for (BufferSet::audio_iterator i = bufs.audio_begin(); i != bufs.audio_end(); ++i, ++chn) {
 		_current_gain[chn] = Amp::apply_gain (*i, _session.nominal_sample_rate(), nframes, _current_gain[chn], _control->inverted (chn) ? -1.f : 1.f);

libs/ardour/port_insert.cc

@@ -147,17 +147,14 @@ PortInsert::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
 		return;
 	}
 
-	if (!_active && !_pending_active) {
+	if (!check_active()) {
 		/* deliver silence */
 		silence (nframes, start_sample);
-		goto out;
+		return;
 	}
 
 	_out->run (bufs, start_sample, end_sample, speed, nframes, true);
 	_input->collect_input (bufs, nframes, ChanCount::ZERO);
-
-out:
-	_active = _pending_active;
 }
 
 XMLNode&

libs/ardour/return.cc

@@ -110,7 +110,7 @@ Return::set_state (const XMLNode& node, int version)
 void
 Return::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, double speed, pframes_t nframes, bool)
 {
-	if ((!_active && !_pending_active) || _input->n_ports() == ChanCount::ZERO) {
+	if (!check_active() || (_input->n_ports() == ChanCount::ZERO)) {
 		return;
 	}
 
@@ -129,8 +129,6 @@ Return::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample,
 			_meter->run (bufs, start_sample, end_sample, speed, nframes, true);
 		}
 	}
-
-	_active = _pending_active;
 }
 
 bool

libs/ardour/send.cc

@@ -221,10 +221,9 @@ Send::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, do
 		return;
 	}
 
-	if (!_active && !_pending_active) {
+	if (!check_active()) {
 		_meter->reset ();
 		_output->silence (nframes);
-		_active = _pending_active;
 		return;
 	}
 

libs/ardour/sidechain.cc

@@ -68,7 +68,7 @@ SideChain::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sampl
 		return;
 	}
 
-	if (!_active && !_pending_active) {
+	if (!check_active()) {
 		// zero buffers
 		for (DataType::iterator t = DataType::begin (); t != DataType::end (); ++t) {
 			for (uint32_t out = _configured_input.get (*t); out < bufs.count ().get (*t); ++out) {
@@ -80,8 +80,6 @@ SideChain::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sampl
 
 	_input->collect_input (bufs, nframes, _configured_input);
 	bufs.set_count (_configured_output);
-
-	_active = _pending_active;
 }
 
 bool