change API of MIDI::Port::drain() to include a maximum blocking time

4 files changed, 9 insertions, 5 deletions

diff --git a/libs/ardour/ardour/async_midi_port.h b/libs/ardour/ardour/async_midi_port.h
index e28c6922d2..96a50ab198 100644
--- a/libs/ardour/ardour/async_midi_port.h
+++ b/libs/ardour/ardour/async_midi_port.h
@@ -58,7 +58,7 @@ class LIBARDOUR_API AsyncMIDIPort : public ARDOUR::MidiPort, public MIDI::Port {
 	int write (const MIDI::byte *msg, size_t msglen, MIDI::timestamp_t timestamp);
         int read (MIDI::byte *buf, size_t bufsize);
 	/* waits for output to be cleared */
-	void drain (int check_interval_usecs);
+        void drain (int check_interval_usecs, int total_usecs_to_wait);
 
 	/* clears async request communication channel */
 	void clear () {
diff --git a/libs/ardour/async_midi_port.cc b/libs/ardour/async_midi_port.cc
index 3dfb5610d9..bbcc0aab85 100644
--- a/libs/ardour/async_midi_port.cc
+++ b/libs/ardour/async_midi_port.cc
@@ -168,7 +168,7 @@ AsyncMIDIPort::cycle_end (MIDI::pframes_t nframes)
  * Cannot be called from a processing thread.
  */
 void
-AsyncMIDIPort::drain (int check_interval_usecs)
+AsyncMIDIPort::drain (int check_interval_usecs, int total_usecs_to_wait)
 {
 	RingBuffer< Evoral::Event<double> >::rw_vector vec = { { 0, 0 }, { 0, 0} };
 
@@ -183,12 +183,16 @@ AsyncMIDIPort::drain (int check_interval_usecs)
 		return;
 	}
 
-	while (1) {
+	microseconds_t now = get_microseconds ();
+	microseconds_t end = now + total_usecs_to_wait;
+
+	while (now < end) {
 		output_fifo.get_write_vector (&vec);
 		if (vec.len[0] + vec.len[1] >= output_fifo.bufsize() - 1) {
 			break;
 		}
 		Glib::usleep (check_interval_usecs);
+		now = get_microseconds();
 	}
 }
 
diff --git a/libs/midi++2/midi++/port.h b/libs/midi++2/midi++/port.h
index 6d933f6a6d..02cc340194 100644
--- a/libs/midi++2/midi++/port.h
+++ b/libs/midi++2/midi++/port.h
@@ -75,7 +75,7 @@ class LIBMIDIPP_API Port {
 	 * executes any part of a JACK process callback (will
 	 * simply return immediately in that situation).
 	 */
-	virtual void drain (int /* check_interval_usecs */) {}
+	virtual void drain (int /* check_interval_usecs */, int /* total_usecs_to_wait */) {}
 
 	/** Write a message to port.
 	 * @return true on success.
diff --git a/libs/surfaces/mackie/surface_port.cc b/libs/surfaces/mackie/surface_port.cc
index 009f45d136..6f6500ffa3 100644
--- a/libs/surfaces/mackie/surface_port.cc
+++ b/libs/surfaces/mackie/surface_port.cc
@@ -99,7 +99,7 @@ SurfacePort::~SurfacePort()
 		}
 
 		if (_async_out) {
-			_output_port->drain (10000);
+			_output_port->drain (10000, 250000);
 			DEBUG_TRACE (DEBUG::MackieControl, string_compose ("unregistering output port %1\n", _async_out->name()));
 			AudioEngine::instance()->unregister_port (_async_out);
 			_async_out.reset ((ARDOUR::Port*) 0);