From 77bb262c26eb3679af1a2c0309e54def7f8380b6 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 7 Mar 2023 15:28:59 +0100
Subject: [PATCH] Add API to check for internal port connections

---
 libs/ardour/ardour/port.h   | 11 ++++++++++-
 libs/ardour/audio_port.cc   |  1 +
 libs/ardour/midi_port.cc    |  3 ++-
 libs/ardour/port.cc         | 12 ++++++++++++
 libs/ardour/port_manager.cc |  6 ++++++
 5 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/libs/ardour/ardour/port.h b/libs/ardour/ardour/port.h
index d8b2af26b2..07fbe9f16e 100644
--- a/libs/ardour/ardour/port.h
+++ b/libs/ardour/ardour/port.h
@@ -119,7 +119,7 @@ public:
 
 	virtual DataType type () const = 0;
 	virtual void cycle_start (pframes_t);
-	virtual void cycle_end (pframes_t) = 0;
+	virtual void cycle_end (pframes_t);
 	virtual void cycle_split () = 0;
 	virtual void reinit (bool) {}
 	virtual Buffer& get_buffer (pframes_t nframes) = 0;
@@ -129,11 +129,18 @@ public:
 	virtual void set_buffer_size (pframes_t) {}
 
 	bool physically_connected () const;
+	bool in_cycle () const { return _in_cycle; }
+
 	uint32_t externally_connected () const { return _externally_connected; }
+	uint32_t internally_connected () const { return _internally_connected; }
 
 	void increment_external_connections() { _externally_connected++; }
 	void decrement_external_connections() { if (_externally_connected) _externally_connected--; }
 
+	void increment_internal_connections() { _internally_connected++; }
+	void decrement_internal_connections() { if (_internally_connected) _internally_connected--; }
+
+
 	PBD::Signal1<void,bool> MonitorInputChanged;
 	PBD::Signal3<void,boost::shared_ptr<Port>,boost::shared_ptr<Port>, bool > ConnectedOrDisconnected;
 
@@ -190,7 +197,9 @@ private:
 	std::string _name;  ///< port short name
 	PortFlags   _flags; ///< flags
 	bool        _last_monitor;
+	bool        _in_cycle;
 	uint32_t    _externally_connected;
+	uint32_t    _internally_connected;
 
 	/** ports that we are connected to, kept so that we can
 	    reconnect to the backend when required
diff --git a/libs/ardour/audio_port.cc b/libs/ardour/audio_port.cc
index 1e6671ebb4..4cee8150da 100644
--- a/libs/ardour/audio_port.cc
+++ b/libs/ardour/audio_port.cc
@@ -89,6 +89,7 @@ AudioPort::cycle_start (pframes_t nframes)
 void
 AudioPort::cycle_end (pframes_t nframes)
 {
+	Port::cycle_end (nframes);
 	if (sends_output() && !_buffer->written() && _port_handle) {
 		if (!_buffer->data (0)) {
 			get_audio_buffer (nframes);
diff --git a/libs/ardour/midi_port.cc b/libs/ardour/midi_port.cc
index 76f3e15f7b..5fcb6f8d92 100644
--- a/libs/ardour/midi_port.cc
+++ b/libs/ardour/midi_port.cc
@@ -225,8 +225,9 @@ MidiPort::read_and_parse_entire_midi_buffer_with_no_speed_adjustment (pframes_t
 }
 
 void
-MidiPort::cycle_end (pframes_t /*nframes*/)
+MidiPort::cycle_end (pframes_t nframes)
 {
+	Port::cycle_end (nframes);
 	_data_fetched_for_cycle = false;
 }
 
diff --git a/libs/ardour/port.cc b/libs/ardour/port.cc
index fae4cf8ad1..492a3ea3a1 100644
--- a/libs/ardour/port.cc
+++ b/libs/ardour/port.cc
@@ -64,7 +64,9 @@ Port::Port (std::string const & n, DataType t, PortFlags f)
 	: _name (n)
 	, _flags (f)
 	, _last_monitor (false)
+	, _in_cycle (false)
 	, _externally_connected (0)
+	, _internally_connected (0)
 {
 	_private_playback_latency.min = 0;
 	_private_playback_latency.max = 0;
@@ -374,8 +376,18 @@ Port::reset ()
 void
 Port::cycle_start (pframes_t)
 {
+	assert (!_in_cycle);
+	_in_cycle = true;
 }
 
+void
+Port::cycle_end (pframes_t)
+{
+	assert (_in_cycle);
+	_in_cycle = false;
+}
+
+
 void
 Port::set_public_latency_range (LatencyRange const& range, bool playback) const
 {
diff --git a/libs/ardour/port_manager.cc b/libs/ardour/port_manager.cc
index cb0a011eee..dc48f0d781 100644
--- a/libs/ardour/port_manager.cc
+++ b/libs/ardour/port_manager.cc
@@ -946,12 +946,18 @@ PortManager::connect_callback (const string& a, const string& b, bool conn)
 			port_a->increment_external_connections ();
 		} else if (port_b && !port_a) {
 			port_b->increment_external_connections ();
+		} else if (port_a && port_b) {
+			port_a->increment_internal_connections ();
+			port_a->increment_internal_connections ();
 		}
 	} else {
 		if (port_a && !port_b) {
 			port_a->decrement_external_connections ();
 		} else if (port_b && !port_a) {
 			port_b->decrement_external_connections ();
+		} else if (port_a && port_b) {
+			port_a->decrement_internal_connections ();
+			port_a->decrement_internal_connections ();
 		}
 	}