Optimize plugin-processing for non-automated params

Keep a dedicated list of automated parameters to evaluate in realtime.
This fixes a performance issue with plugins that have many controls
with only few of them being automated.

libs/ardour/ardour/automatable.h

@@ -26,6 +26,7 @@
 
 #include <boost/shared_ptr.hpp>
 
+#include "pbd/rcu.h"
 #include "pbd/signals.h"
 
 #include "evoral/ControlSet.hpp"
@@ -88,7 +89,7 @@ public:
 	virtual void non_realtime_locate (samplepos_t now);
 	virtual void non_realtime_transport_stop (samplepos_t now, bool flush);
 
-	virtual void automation_run (samplepos_t, pframes_t);
+	virtual void automation_run (samplepos_t, pframes_t, bool only_active = false);
 
 	virtual std::string describe_parameter(Evoral::Parameter param);
 
@@ -112,7 +113,8 @@ protected:
 
 	void can_automate(Evoral::Parameter);
 
-	virtual void automation_list_automation_state_changed (Evoral::Parameter, AutoState) {}
+	virtual void automation_list_automation_state_changed (Evoral::Parameter, AutoState);
+	SerializedRCUManager<ControlList> _automated_controls;
 
 	int load_automation (const std::string& path);
 	int old_set_automation_state(const XMLNode&);

libs/ardour/ardour/plugin_insert.h

@@ -79,7 +79,7 @@ public:
 
 	bool write_immediate_event (size_t size, const uint8_t* buf);
 
-	void automation_run (samplepos_t, pframes_t);
+	void automation_run (samplepos_t, pframes_t, bool only_active = false);
 	bool find_next_event (double, double, Evoral::ControlEvent&, bool only_active = true) const;
 
 	int set_block_size (pframes_t nframes);

libs/ardour/automatable.cc

@@ -55,13 +55,15 @@ const string Automatable::xml_node_name = X_("Automation");
 
 Automatable::Automatable(Session& session)
 	: _a_session(session)
+	, _automated_controls (new ControlList)
 {
 }
 
 Automatable::Automatable (const Automatable& other)
-        : ControlSet (other)
-        , Slavable ()
-        , _a_session (other._a_session)
+	: ControlSet (other)
+	, Slavable ()
+	, _a_session (other._a_session)
+	, _automated_controls (new ControlList)
 {
         Glib::Threads::Mutex::Lock lm (other._control_lock);
 
@@ -73,6 +75,13 @@ Automatable::Automatable (const Automatable& other)
 
 Automatable::~Automatable ()
 {
+	{
+		RCUWriter<ControlList> writer (_automated_controls);
+		boost::shared_ptr<ControlList> cl = writer.get_copy ();
+		cl->clear ();
+	}
+	_automated_controls.flush ();
+
 	Glib::Threads::Mutex::Lock lm (_control_lock);
 	for (Controls::const_iterator li = _controls.begin(); li != _controls.end(); ++li) {
 		boost::dynamic_pointer_cast<AutomationControl>(li->second)->drop_references ();
@@ -439,8 +448,16 @@ Automatable::non_realtime_transport_stop (samplepos_t now, bool /*flush_processo
 }
 
 void
-Automatable::automation_run (samplepos_t start, pframes_t nframes)
+Automatable::automation_run (samplepos_t start, pframes_t nframes, bool only_active)
 {
+	if (only_active) {
+		boost::shared_ptr<ControlList> cl = _automated_controls.reader ();
+		for (ControlList::const_iterator ci = cl->begin(); ci != cl->end(); ++ci) {
+			(*ci)->automation_run (start, nframes);
+		}
+		return;
+	}
+
 	for (Controls::iterator li = controls().begin(); li != controls().end(); ++li) {
 		boost::shared_ptr<AutomationControl> c =
 			boost::dynamic_pointer_cast<AutomationControl>(li->second);
@@ -451,6 +468,35 @@ Automatable::automation_run (samplepos_t start, pframes_t nframes)
 	}
 }
 
+void
+Automatable::automation_list_automation_state_changed (Evoral::Parameter param, AutoState as)
+{
+	{
+		boost::shared_ptr<AutomationControl> c (automation_control(param));
+		assert (c && c->list());
+
+		RCUWriter<ControlList> writer (_automated_controls);
+		boost::shared_ptr<ControlList> cl = writer.get_copy ();
+
+		ControlList::const_iterator fi = std::find (cl->begin(), cl->end(), c);
+		if (fi != cl->end()) {
+			cl->erase (fi);
+		}
+		switch (as) {
+			/* all potential  automation_playback() states */
+			case Play:
+			case Touch:
+			case Latch:
+				cl->push_back (c);
+				break;
+			case Off:
+			case Write:
+				break;
+		}
+	}
+	_automated_controls.flush();
+}
+
 boost::shared_ptr<Evoral::Control>
 Automatable::control_factory(const Evoral::Parameter& param)
 {

libs/ardour/plugin_insert.cc

@@ -589,7 +589,7 @@ PluginInsert::set_block_size (pframes_t nframes)
 }
 
 void
-PluginInsert::automation_run (samplepos_t start, pframes_t nframes)
+PluginInsert::automation_run (samplepos_t start, pframes_t nframes, bool only_active)
 {
 	// XXX does not work when rolling backwards
 	if (_loop_location && nframes > 0) {
@@ -607,13 +607,13 @@ PluginInsert::automation_run (samplepos_t start, pframes_t nframes)
 			}
 			samplecnt_t move = std::min ((samplecnt_t)nframes, loop_end - start_pos);
 
-			Automatable::automation_run (start_pos, move);
+			Automatable::automation_run (start_pos, move, only_active);
 			remain -= move;
 			start_pos += move;
 		}
 		return;
 	}
-	Automatable::automation_run (start, nframes);
+	Automatable::automation_run (start, nframes, only_active);
 }
 
 bool
@@ -880,6 +880,7 @@ PluginInsert::connect_and_run (BufferSet& bufs, samplepos_t start, samplepos_t e
 
 	if (with_auto) {
 
+#if 0
 		uint32_t n = 0;
 
 		for (Controls::const_iterator li = controls().begin(); li != controls().end(); ++li, ++n) {
@@ -898,6 +899,21 @@ PluginInsert::connect_and_run (BufferSet& bufs, samplepos_t start, samplepos_t e
 				}
 			}
 		}
+#else
+		boost::shared_ptr<ControlList> cl = _automated_controls.reader ();
+		for (ControlList::const_iterator ci = cl->begin(); ci != cl->end(); ++ci) {
+			AutomationControl& c = *(ci->get());
+			boost::shared_ptr<const Evoral::ControlList> clist (c.list());
+			/* we still need to check for Touch and Latch */
+			if (clist && (static_cast<AutomationList const&> (*clist)).automation_playback ()) {
+				bool valid;
+				const float val = c.list()->rt_safe_eval (start, valid);
+				if (valid) {
+					c.set_value_unchecked(val);
+				}
+			}
+		}
+#endif
 	}
 
 	/* Calculate if, and how many samples we need to collect for analysis */
@@ -1188,7 +1204,7 @@ PluginInsert::bypass (BufferSet& bufs, pframes_t nframes)
 void
 PluginInsert::silence (samplecnt_t nframes, samplepos_t start_sample)
 {
-	automation_run (start_sample, nframes); // evaluate automation only
+	automation_run (start_sample, nframes, true); // evaluate automation only
 
 	if (!active ()) {
 		// XXX delaybuffers need to be offset by nframes
@@ -1254,7 +1270,7 @@ PluginInsert::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sa
 		// XXX should call ::silence() to run plugin(s) for consistent load.
 		// We'll need to change this anyway when bypass can be automated
 		bypass (bufs, nframes);
-		automation_run (start_sample, nframes); // evaluate automation only
+		automation_run (start_sample, nframes, true); // evaluate automation only
 		_delaybuffers.flush ();
 	}