X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fsession_process.cc;h=680f2861de2a2bdae8e90515ea89c96ef1fdd0d8;hb=f6aaa1660bbce1782b8292d106c8adfb1ecbdc16;hp=d67744dbe75d041b3a82a07078754e1d212d6781;hpb=d795980546156b5094a23b465f68c9c9472818b7;p=ardour.git

diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index d67744dbe7..680f2861de 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -25,21 +25,22 @@
 #include "pbd/error.h"
 #include "pbd/enumwriter.h"
 
-#include <glibmm/thread.h>
+#include <glibmm/threads.h>
 
-#include "ardour/ardour.h"
 #include "ardour/audioengine.h"
 #include "ardour/auditioner.h"
 #include "ardour/butler.h"
+#include "ardour/cycle_timer.h"
 #include "ardour/debug.h"
+#include "ardour/graph.h"
+#include "ardour/port.h"
 #include "ardour/process_thread.h"
+#include "ardour/scene_changer.h"
 #include "ardour/session.h"
 #include "ardour/slave.h"
-#include "ardour/timestamps.h"
-#include "ardour/graph.h"
-#include "ardour/audio_port.h"
+#include "ardour/ticker.h"
+#include "ardour/types.h"
 
-#include "midi++/manager.h"
 #include "midi++/mmc.h"
 
 #include "i18n.h"
@@ -51,10 +52,11 @@ using namespace std;
 /** Called by the audio engine when there is work to be done with JACK.
  * @param nframes Number of frames to process.
  */
+
 void
 Session::process (pframes_t nframes)
 {
-	MIDI::Manager::instance()->cycle_start(nframes);
+	framepos_t transport_at_start = _transport_frame;
 
 	_silent = false;
 
@@ -75,17 +77,24 @@ Session::process (pframes_t nframes)
 
 	_engine.main_thread()->drop_buffers ();
 
-	// the ticker is for sending time information like MidiClock
-	framepos_t transport_frames = transport_frame();
-	Timecode::BBT_Time transport_bbt;
-	bbt_time(transport_frames, transport_bbt);
-	Timecode::Time transport_timecode;
-	timecode_time(transport_frames, transport_timecode);
-	tick (transport_frames, transport_bbt, transport_timecode); /* EMIT SIGNAL */
+	/* deliver MIDI clock. Note that we need to use the transport frame
+	 * position at the start of process(), not the value at the end of
+	 * it. We may already have ticked() because of a transport state
+	 * change, for example.
+	 */
+
+	try {
+		if (!_silent && !_engine.freewheeling() && Config->get_send_midi_clock() && (transport_speed() == 1.0f || transport_speed() == 0.0f) && midi_clock->has_midi_port()) {
+			midi_clock->tick (transport_at_start, nframes);
+		}
 
-	SendFeedback (); /* EMIT SIGNAL */
+		_scene_changer->run (transport_at_start, transport_at_start + nframes);
 
-	MIDI::Manager::instance()->cycle_end();
+	} catch (...) {
+		/* don't bother with a message */
+	}
+
+	SendFeedback (); /* EMIT SIGNAL */
 }
 
 int
@@ -97,44 +106,52 @@ Session::fail_roll (pframes_t nframes)
 int
 Session::no_roll (pframes_t nframes)
 {
+	PT_TIMING_CHECK (4);
+	
 	framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
 	int ret = 0;
-	bool declick = get_transport_declick_required();
+	int declick = get_transport_declick_required();
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
 	if (_click_io) {
 		_click_io->silence (nframes);
 	}
 
-	DEBUG_TRACE(DEBUG::Graph,"calling graph/no-roll\n");
-	route_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), actively_recording(), declick);
-        /*
-	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+	ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 
-		if ((*i)->is_hidden()) {
-			continue;
-		}
+	if (_process_graph) {
+		DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
+		_process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
+	} else {
+		PT_TIMING_CHECK (10);
+		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-		(*i)->set_pending_declick (declick);
+			if ((*i)->is_auditioner()) {
+				continue;
+			}
 
-		if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending(),
-				   actively_recording(), declick)) {
-			error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
-			ret = -1;
-			break;
+			(*i)->set_pending_declick (declick);
+
+			if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending())) {
+				error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
+				ret = -1;
+				break;
+			}
 		}
+		PT_TIMING_CHECK (11);
 	}
-        */
 
+	PT_TIMING_CHECK (5);
 	return ret;
 }
 
+/** @param need_butler to be set to true by this method if it needs the butler,
+ *  otherwise it must be left alone.
+ */
 int
 Session::process_routes (pframes_t nframes, bool& need_butler)
 {
-	bool record_active;
 	int  declick = get_transport_declick_required();
-	bool rec_monitors = get_rec_monitors_input();
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
 	if (transport_sub_state & StopPendingCapture) {
@@ -142,65 +159,75 @@ Session::process_routes (pframes_t nframes, bool& need_butler)
 		declick = -1;
 	}
 
-	record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
-
 	const framepos_t start_frame = _transport_frame;
 	const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
+	
+	if (_process_graph) {
+		DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
+		_process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler);
+	} else {
 
-	DEBUG_TRACE(DEBUG::Graph,"calling graph/process-routes\n");
-	route_graph->process_routes( nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler);
-/*
-	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-		int ret;
+			int ret;
 
-		if ((*i)->is_hidden()) {
-			continue;
-		}
+			if ((*i)->is_auditioner()) {
+				continue;
+			}
 
-		(*i)->set_pending_declick (declick);
+			(*i)->set_pending_declick (declick);
 
-		if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler)) < 0) {
-			stop_transport ();
-			return -1;
+			bool b = false;
+
+			if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, b)) < 0) {
+				stop_transport ();
+				return -1;
+			}
+
+			if (b) {
+				need_butler = true;
+			}
 		}
 	}
-*/
+
 	return 0;
 }
 
+/** @param need_butler to be set to true by this method if it needs the butler,
+ *  otherwise it must be left alone.
+ */
 int
 Session::silent_process_routes (pframes_t nframes, bool& need_butler)
 {
-	bool record_active = actively_recording();
-	int  declick = get_transport_declick_required();
-	bool rec_monitors = get_rec_monitors_input();
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
-	if (transport_sub_state & StopPendingCapture) {
-		/* force a declick out */
-		declick = -1;
-	}
-
 	const framepos_t start_frame = _transport_frame;
 	const framepos_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 
-	route_graph->silent_process_routes( nframes, start_frame, end_frame, record_active, rec_monitors, need_butler);
-/*
-	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+	if (_process_graph) {
+		_process_graph->silent_process_routes (nframes, start_frame, end_frame, need_butler);
+	} else {
+		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-		int ret;
+			int ret;
 
-		if ((*i)->is_hidden()) {
-			continue;
-		}
+			if ((*i)->is_auditioner()) {
+				continue;
+			}
 
-		if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, record_active, rec_monitors, need_butler)) < 0) {
-			stop_transport ();
-			return -1;
+			bool b = false;
+
+			if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, b)) < 0) {
+				stop_transport ();
+				return -1;
+			}
+
+			if (b) {
+				need_butler = true;
+			}
 		}
 	}
-*/
+
 	return 0;
 }
 
@@ -235,11 +262,12 @@ Session::get_track_statistics ()
 void
 Session::process_with_events (pframes_t nframes)
 {
+	PT_TIMING_CHECK (3);
+	
 	SessionEvent*  ev;
 	pframes_t      this_nframes;
 	framepos_t     end_frame;
 	bool           session_needs_butler = false;
-	framepos_t     stop_limit;
 	framecnt_t     frames_moved;
 
 	/* make sure the auditioner is silent */
@@ -270,17 +298,29 @@ Session::process_with_events (pframes_t nframes)
 	bool const was_sending_qf_mtc = _send_qf_mtc;
 	double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
 
-	_send_qf_mtc = (
-		Config->get_send_mtc () &&
-		_transport_speed >= (1 - tolerance) &&
-		_transport_speed <= (1 + tolerance)
-		);
+	if (_transport_speed != 0) {
+		_send_qf_mtc = (
+			Config->get_send_mtc () &&
+			_transport_speed >= (1 - tolerance) &&
+			_transport_speed <= (1 + tolerance)
+			);
 
-	if (_send_qf_mtc && !was_sending_qf_mtc) {
-		/* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
-		_send_timecode_update = true;
+		if (_send_qf_mtc && !was_sending_qf_mtc) {
+			/* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
+			_send_timecode_update = true;
+		}
+
+		if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
+			/* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
+			   a quarter of a second since we sent anything at all, so send a full MTC update
+			   this cycle.
+			*/
+			_send_timecode_update = true;
+		}
+
+		_pframes_since_last_mtc += nframes;
 	}
-	
+
 	/* Events caused a transport change (or we re-started sending
 	 * MTC), so send an MTC Full Frame (Timecode) message.  This
 	 * is sent whether rolling or not, to give slaves an idea of
@@ -288,7 +328,7 @@ Session::process_with_events (pframes_t nframes)
 	 * and prepare for rolling)
 	 */
 	if (_send_timecode_update) {
-		send_full_time_code (_transport_frame);
+		send_full_time_code (_transport_frame, nframes);
 	}
 
 	if (!process_can_proceed()) {
@@ -304,8 +344,8 @@ Session::process_with_events (pframes_t nframes)
 	if (_transport_speed == 1.0) {
 		frames_moved = (framecnt_t) nframes;
 	} else {
-		interpolation.set_target_speed (fabs(_target_transport_speed));
-		interpolation.set_speed (fabs(_transport_speed));
+		interpolation.set_target_speed (_target_transport_speed);
+		interpolation.set_speed (_transport_speed);
 		frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 	}
 
@@ -335,16 +375,7 @@ Session::process_with_events (pframes_t nframes)
 			send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
 		}
 
-		if (actively_recording()) {
-			stop_limit = max_framepos;
-		} else {
-
-			if (Config->get_stop_at_session_end()) {
-				stop_limit = current_end_frame();
-			} else {
-				stop_limit = max_framepos;
-			}
-		}
+		framepos_t stop_limit = compute_stop_limit ();
 
 		if (maybe_stop (stop_limit)) {
 			no_roll (nframes);
@@ -394,7 +425,9 @@ Session::process_with_events (pframes_t nframes)
 				check_declick_out ();
 			}
 
-			_engine.split_cycle (this_nframes);
+			if (nframes > 0) {
+				_engine.split_cycle (this_nframes);
+			}
 
 			/* now handle this event and all others scheduled for the same time */
 
@@ -418,7 +451,6 @@ Session::process_with_events (pframes_t nframes)
 
 			/* this is necessary to handle the case of seamless looping */
 			end_frame = _transport_frame + floor (nframes * _transport_speed);
-
 		}
 
 		set_next_event ();
@@ -486,7 +518,9 @@ Session::follow_slave (pframes_t nframes)
 		slave_speed = 0.0f;
 	}
 
-	if (_slave->is_always_synced() || config.get_timecode_source_is_synced()) {
+	if (_slave->is_always_synced() ||
+			(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
+			) {
 
 		/* if the TC source is synced, then we assume that its
 		   speed is binary: 0.0 or 1.0
@@ -512,9 +546,11 @@ Session::follow_slave (pframes_t nframes)
 
 	DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 						   _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
-		     
 
-	if (_slave_state == Running && !_slave->is_always_synced() && !config.get_timecode_source_is_synced()) {
+
+	if (_slave_state == Running && !_slave->is_always_synced() &&
+			!(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
+			) {
 
 		if (_transport_speed != 0.0f) {
 
@@ -539,11 +575,11 @@ Session::follow_slave (pframes_t nframes)
 									   slave_speed,
 									   _transport_speed,
 									   _transport_frame,
-									   slave_transport_frame, 
+									   slave_transport_frame,
 									   average_slave_delta));
 			}
 #endif
-			
+
 			if (_slave->give_slave_full_control_over_transport_speed()) {
 				set_transport_speed (slave_speed, false, false);
 				//std::cout << "set speed = " << slave_speed << "\n";
@@ -554,9 +590,9 @@ Session::follow_slave (pframes_t nframes)
 									   delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 									   slave_speed));
 			}
-			
+
 #if 1
-			if ((framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
+			if (!actively_recording() && (framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
 				cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
 				goto silent_motion;
 			}
@@ -609,7 +645,7 @@ Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta
 }
 
 void
-Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t this_delta)
+Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
 {
 	if (slave_speed != 0.0f) {
 
@@ -626,7 +662,10 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
 
 			} else {
 
-				_slave_state = Running;
+				DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_frame));
+
+				memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
+				average_slave_delta = 0L;
 
 				Location* al = _locations->auto_loop_location();
 
@@ -636,8 +675,10 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
 				}
 
 				if (slave_transport_frame != _transport_frame) {
+					DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_frame, slave_transport_frame));
 					locate (slave_transport_frame, false, false);
 				}
+				_slave_state = Running;
 			}
 			break;
 
@@ -686,10 +727,6 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
 					cerr << "cannot micro-seek\n";
 					/* XXX what? */
 				}
-
-				memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
-				average_slave_delta = 0L;
-				this_delta = 0;
 			}
 		}
 
@@ -704,7 +741,7 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
 
 		if (_transport_speed != 0.0f) {
 			DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
-			stop_transport();
+			stop_transport ();
 		}
 
 		if (slave_transport_frame != _transport_frame) {
@@ -712,7 +749,7 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
 			force_locate (slave_transport_frame, false);
 		}
 
-		_slave_state = Stopped;
+		reset_slave_state();
 	}
 }
 
@@ -742,19 +779,8 @@ Session::follow_slave_silently (pframes_t nframes, float slave_speed)
 		} else {
 			increment_transport_position (frames_moved);
 		}
-                
-		framepos_t stop_limit;
-
-		if (actively_recording()) {
-			stop_limit = max_framepos;
-		} else {
-			if (Config->get_stop_at_session_end()) {
-				stop_limit = current_end_frame();
-			} else {
-				stop_limit = max_framepos;
-			}
-		}
 
+		framepos_t const stop_limit = compute_stop_limit ();
 		maybe_stop (stop_limit);
 	}
 }
@@ -763,7 +789,6 @@ void
 Session::process_without_events (pframes_t nframes)
 {
 	bool session_needs_butler = false;
-	framepos_t stop_limit;
 	framecnt_t frames_moved;
 
 	if (!process_can_proceed()) {
@@ -773,6 +798,7 @@ Session::process_without_events (pframes_t nframes)
 
 	if (!_exporting && _slave) {
 		if (!follow_slave (nframes)) {
+			ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame, 0, 0 , nframes);
 			return;
 		}
 	}
@@ -785,24 +811,18 @@ Session::process_without_events (pframes_t nframes)
 	if (_transport_speed == 1.0) {
 		frames_moved = (framecnt_t) nframes;
 	} else {
-		interpolation.set_target_speed (fabs(_target_transport_speed));
-		interpolation.set_speed (fabs(_transport_speed));
+		interpolation.set_target_speed (_target_transport_speed);
+		interpolation.set_speed (_transport_speed);
 		frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 	}
-	
+
 	if (!_exporting && !timecode_transmission_suspended()) {
 		send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
 	}
 
-	if (actively_recording()) {
-		stop_limit = max_framepos;
-	} else {
-		if (Config->get_stop_at_session_end()) {
-			stop_limit = current_end_frame();
-		} else {
-			stop_limit = max_framepos;
-		}
-	}
+	ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, _target_transport_speed, _transport_speed, nframes);
+
+	framepos_t const stop_limit = compute_stop_limit ();
 
 	if (maybe_stop (stop_limit)) {
 		fail_roll (nframes);
@@ -846,7 +866,7 @@ Session::process_audition (pframes_t nframes)
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-		if (!(*i)->is_hidden()) {
+		if (!(*i)->is_auditioner()) {
 			(*i)->silence (nframes);
 		}
 	}
@@ -857,12 +877,12 @@ Session::process_audition (pframes_t nframes)
 		_butler->summon ();
 	}
 
-        /* if using a monitor section, run it because otherwise we don't hear anything */
+	/* if using a monitor section, run it because otherwise we don't hear anything */
+
+	if (_monitor_out && auditioner->needs_monitor()) {
+		_monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
+	}
 
-        if (auditioner->needs_monitor()) {
-                _monitor_out->passthru (_transport_frame, _transport_frame + nframes, nframes, false);
-        }
-        
 	/* handle pending events */
 
 	while (pending_events.read (&ev, 1) == 1) {
@@ -904,7 +924,7 @@ Session::maybe_sync_start (pframes_t & nframes)
 
 		no_roll (sync_offset);
 		nframes -= sync_offset;
-		AudioPort::increment_port_offset (sync_offset);
+		Port::increment_global_port_buffer_offset (sync_offset);
 		waiting_for_sync_offset = false;
 
 		if (nframes == 0) {
@@ -994,23 +1014,37 @@ Session::process_event (SessionEvent* ev)
 
 	switch (ev->type) {
 	case SessionEvent::SetLoop:
-		set_play_loop (ev->yes_or_no);
+		set_play_loop (ev->yes_or_no, ev->speed);
 		break;
 
 	case SessionEvent::AutoLoop:
 		if (play_loop) {
+			/* roll after locate, do not flush, set "with loop"
+			   true only if we are seamless looping
+			*/
 			start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
 		}
 		remove = false;
 		del = false;
 		break;
 
+	case SessionEvent::AutoLoopDeclick:
+		if (play_loop) {
+			/* Request a declick fade-out and a fade-in; the fade-out will happen
+			   at the end of the loop, and the fade-in at the start.
+			*/
+			transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
+		}
+		remove = false;
+		del = false;
+		break;
+
 	case SessionEvent::Locate:
 		if (ev->yes_or_no) {
-			// cerr << "forced locate to " << ev->target_frame << endl;
+			/* args: do not roll after locate, do flush, not with loop */
 			locate (ev->target_frame, false, true, false);
 		} else {
-			// cerr << "soft locate to " << ev->target_frame << endl;
+			/* args: do not roll after locate, do flush, not with loop */
 			start_locate (ev->target_frame, false, true, false);
 		}
 		_send_timecode_update = true;
@@ -1018,10 +1052,10 @@ Session::process_event (SessionEvent* ev)
 
 	case SessionEvent::LocateRoll:
 		if (ev->yes_or_no) {
-			// cerr << "forced locate to+roll " << ev->target_frame << endl;
+			/* args: roll after locate, do flush, not with loop */
 			locate (ev->target_frame, true, true, false);
 		} else {
-			// cerr << "soft locate to+roll " << ev->target_frame << endl;
+			/* args: roll after locate, do flush, not with loop */
 			start_locate (ev->target_frame, true, true, false);
 		}
 		_send_timecode_update = true;
@@ -1035,7 +1069,7 @@ Session::process_event (SessionEvent* ev)
 
 
 	case SessionEvent::SetTransportSpeed:
-		set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no);
+		set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
 		break;
 
 	case SessionEvent::PunchIn:
@@ -1074,6 +1108,7 @@ Session::process_event (SessionEvent* ev)
 		break;
 
 	case SessionEvent::RangeLocate:
+		/* args: roll after locate, do flush, not with loop */
 		start_locate (ev->target_frame, true, true, false);
 		remove = false;
 		del = false;
@@ -1088,6 +1123,7 @@ Session::process_event (SessionEvent* ev)
 		break;
 
 	case SessionEvent::SetSyncSource:
+		DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
 		use_sync_source (ev->slave);
 		break;
 
@@ -1111,13 +1147,13 @@ Session::process_event (SessionEvent* ev)
 		del = false; // other side of RT request needs to clean up
 		break;
 
-        case SessionEvent::AdjustPlaybackBuffering:
-                schedule_playback_buffering_adjustment ();
-                break;
+	case SessionEvent::AdjustPlaybackBuffering:
+		schedule_playback_buffering_adjustment ();
+		break;
 
-        case SessionEvent::AdjustCaptureBuffering:
-                schedule_capture_buffering_adjustment ();
-                break;
+	case SessionEvent::AdjustCaptureBuffering:
+		schedule_capture_buffering_adjustment ();
+		break;
 
 	case SessionEvent::SetTimecodeTransmission:
 		g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
@@ -1138,3 +1174,31 @@ Session::process_event (SessionEvent* ev)
 	}
 }
 
+framepos_t
+Session::compute_stop_limit () const
+{
+	if (!Config->get_stop_at_session_end ()) {
+		return max_framepos;
+	}
+
+	if (_slave) {
+		return max_framepos;
+	}
+
+	
+	bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
+	bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
+
+	if (actively_recording ()) {
+		/* permanently recording */
+		return max_framepos;
+	} else if (punching_in && !punching_out) {
+		/* punching in but never out */
+		return max_framepos;
+	} else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
+		/* punching in and punching out after session end */
+		return max_framepos;
+	}
+
+	return current_end_frame ();
+}