prevent double registration of ALSA sequencer MIDI ports

git-svn-id: svn://localhost/ardour2/branches/2.0-ongoing@4074 d708f5d6-7413-0410-9779-e7cbd77b26cf

2 files changed, 45 insertions, 0 deletions

diff --git a/libs/midi++2/alsa_sequencer_midiport.cc b/libs/midi++2/alsa_sequencer_midiport.cc
index dc6ea9092f..f7ce4ad165 100644
--- a/libs/midi++2/alsa_sequencer_midiport.cc
+++ b/libs/midi++2/alsa_sequencer_midiport.cc
@@ -171,6 +171,8 @@ ALSA_SequencerMidiPort::create_ports (const Port::Descriptor& desc)
 		caps |= SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE;
 	if (desc.mode == O_RDONLY  ||  desc.mode == O_RDWR)
 		caps |= SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ;
+
+	cerr << "Create ALSA MIDI port for " << desc.tag << endl;
 	
 	if (0 <= (err = snd_seq_create_simple_port (seq, desc.tag.c_str(), caps, 
 						    (SND_SEQ_PORT_TYPE_MIDI_GENERIC|
@@ -312,6 +314,8 @@ ALSA_SequencerMidiPort::get_connections (vector<SequencerPortAddress>& connectio
 	while (snd_seq_query_port_subscribers(seq, subs) >= 0) {
 
 		seq_addr = *snd_seq_query_subscribe_get_addr (subs);
+
+		cerr << _tagname << " is connected to " << seq_addr.client << "/" << seq_addr.port << endl;
 		
 		connections.push_back (SequencerPortAddress (seq_addr.client,
 							     seq_addr.port));
diff --git a/libs/midi++2/midimanager.cc b/libs/midi++2/midimanager.cc
index 3791d409d7..7cfdb3bcdc 100644
--- a/libs/midi++2/midimanager.cc
+++ b/libs/midi++2/midimanager.cc
@@ -71,6 +71,47 @@ Manager::add_port (const XMLNode& node)
 	PortMap::iterator existing;
 	pair<string, Port *> newpair;
 
+	/* do not allow multiple ports with the same tag. if attempted, just return the existing
+	   port with the same tag. XXX this is really caused by the mess of setup_midi() being
+	   called twice in Ardour, once in the global init() function and once after the user RC file
+	   has been loaded (there may be extra ports in it). 
+	 */
+
+	if ((existing = ports_by_tag.find (desc.tag)) != ports_by_tag.end()) {
+
+		port = (*existing).second;
+		
+		if (port->mode() == desc.mode) {
+			
+			/* Same mode - reuse the port, and just
+			   create a new tag entry.
+			*/
+			
+			newpair.first = desc.tag;
+			newpair.second = port;
+			
+			ports_by_tag.insert (newpair);
+			return port;
+		}
+		
+		/* If the existing is duplex, and this request
+		   is not, then fail, because most drivers won't
+		   allow opening twice with duplex and non-duplex
+		   operation.
+		*/
+		
+		if ((desc.mode == O_RDWR && port->mode() != O_RDWR) ||
+		    (desc.mode != O_RDWR && port->mode() == O_RDWR)) {
+			error << "MIDIManager: port tagged \""
+			      << desc.tag
+			      << "\" cannot be opened duplex and non-duplex"
+			      << endmsg;
+			return 0;
+		}
+		
+		/* modes must be different or complementary */
+	}
+
 	if (!PortFactory::ignore_duplicate_devices (desc.type)) {
 
 		if ((existing = ports_by_device.find (desc.device)) != ports_by_device.end()) {