X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fsession_process.cc;h=8a677105bd81509398a54829e2ad21c54a0be2f8;hb=a473d630eb165272992e90f8d854b1d66ec0be63;hp=0f697806eb6fe1b18d7dcd5246209228e12a9ee4;hpb=e0aaed6d65f160c328cb8b56d7c6552ee15d65e2;p=ardour.git

diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index 0f697806eb..8a677105bd 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 1999-2002 Paul Davis 
+    Copyright (C) 1999-2002 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -23,20 +23,24 @@
 #include <unistd.h>
 
 #include "pbd/error.h"
+#include "pbd/enumwriter.h"
 
 #include <glibmm/thread.h>
 
 #include "ardour/ardour.h"
-#include "ardour/session.h"
-#include "ardour/timestamps.h"
-#include "ardour/audio_diskstream.h"
 #include "ardour/audioengine.h"
-#include "ardour/slave.h"
 #include "ardour/auditioner.h"
-#include "ardour/cycles.h"
-#include "ardour/cycle_timer.h"
+#include "ardour/butler.h"
+#include "ardour/debug.h"
+#include "ardour/process_thread.h"
+#include "ardour/session.h"
+#include "ardour/slave.h"
+#include "ardour/timestamps.h"
+#include "ardour/graph.h"
+#include "ardour/audio_port.h"
 
 #include "midi++/manager.h"
+#include "midi++/mmc.h"
 
 #include "i18n.h"
 
@@ -47,79 +51,80 @@ 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 (nframes_t nframes)
+Session::process (pframes_t nframes)
 {
-	// This is no more the appropriate place to call cycle
-	// start. cycle_start needs to be called at the Route::roll()
-	// where the signals which we want to mixdown have been calculated.
-	//
 	MIDI::Manager::instance()->cycle_start(nframes);
 
 	_silent = false;
 
+	if (processing_blocked()) {
+		_silent = true;
+		return;
+	}
+
 	if (non_realtime_work_pending()) {
-		if (!transport_work_requested ()) {
+		if (!_butler->transport_work_requested ()) {
 			post_transport ();
-		} 
-	} 
-	
+		}
+	}
+
+	_engine.main_thread()->get_buffers ();
+
 	(this->*process_function) (nframes);
-	
+
+	_engine.main_thread()->drop_buffers ();
+
 	// the ticker is for sending time information like MidiClock
-	nframes_t transport_frames = transport_frame();
-	BBT_Time  transport_bbt;
+	framepos_t transport_frames = transport_frame();
+	Timecode::BBT_Time transport_bbt;
 	bbt_time(transport_frames, transport_bbt);
-	SMPTE::Time transport_smpte;
-	smpte_time(transport_frames, transport_smpte);
-	tick (transport_frames, transport_bbt, transport_smpte); /* EMIT SIGNAL */
-	
+	Timecode::Time transport_timecode;
+	timecode_time(transport_frames, transport_timecode);
+	tick (transport_frames, transport_bbt, transport_timecode); /* EMIT SIGNAL */
+
 	SendFeedback (); /* EMIT SIGNAL */
-	
+
 	MIDI::Manager::instance()->cycle_end();
 }
 
-void
-Session::prepare_diskstreams ()
+int
+Session::fail_roll (pframes_t nframes)
 {
-	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
-		(*i)->prepare ();
-	}
+	return no_roll (nframes);
 }
 
 int
-Session::no_roll (nframes_t nframes, nframes_t offset)
+Session::no_roll (pframes_t nframes)
 {
-	nframes_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
+	framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
 	int ret = 0;
 	bool declick = get_transport_declick_required();
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
 	if (_click_io) {
-		_click_io->silence (nframes, offset);
+		_click_io->silence (nframes);
 	}
 
-	if (g_atomic_int_get (&processing_prohibited)) {
+	if (route_graph->threads_in_use() > 0) {
+		DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
+		route_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), actively_recording(), declick);
+	} else {
 		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-			(*i)->silence (nframes, offset);
-		}
-		return 0;
-	}
 
-	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-		
-		if ((*i)->is_hidden()) {
-			continue;
-		}
-		
-		(*i)->set_pending_declick (declick);
-		
-		if ((*i)->no_roll (nframes, _transport_frame, end_frame, offset, non_realtime_work_pending(), 
-				   actively_recording(), declick)) {
-			error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
-			ret = -1;
-			break;
+			if ((*i)->is_hidden()) {
+				continue;
+			}
+
+			(*i)->set_pending_declick (declick);
+
+			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;
+			}
 		}
 	}
 
@@ -127,7 +132,7 @@ Session::no_roll (nframes_t nframes, nframes_t offset)
 }
 
 int
-Session::process_routes (nframes_t nframes, nframes_t offset)
+Session::process_routes (pframes_t nframes, bool& need_butler)
 {
 	bool record_active;
 	int  declick = get_transport_declick_required();
@@ -141,41 +146,40 @@ Session::process_routes (nframes_t nframes, nframes_t offset)
 
 	record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 
-	const nframes_t start_frame = _transport_frame;
-	const nframes_t end_frame = _transport_frame + (nframes_t)floor(nframes * _transport_speed);
-
-	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+	const framepos_t start_frame = _transport_frame;
+	const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
 
-		int ret;
+	/* XXX this is hack to force use of the graph even if we are only
+	   using 1 thread. its needed because otherwise when we remove
+	   tracks, the graph never gets updated.
+	*/
+	if (1 || route_graph->threads_in_use() > 0) {
+		DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
+		route_graph->process_routes( nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler);
+	} else {
 
-		if ((*i)->is_hidden()) {
-			continue;
-		}
+		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-		(*i)->set_pending_declick (declick);
+			int ret;
 
-		if ((ret = (*i)->roll (nframes, start_frame, end_frame, offset, declick, record_active, rec_monitors)) < 0) {
+			if ((*i)->is_hidden()) {
+				continue;
+			}
 
-			/* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
-			   and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
-			   call path, so make sure we release any outstanding locks here before we return failure.
-			*/
+			(*i)->set_pending_declick (declick);
 
-			boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-			for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
-				(*ids)->recover ();
+			if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler)) < 0) {
+				stop_transport ();
+				return -1;
 			}
-
-			stop_transport ();
-			return -1;
-		} 
+		}
 	}
 
 	return 0;
 }
 
 int
-Session::silent_process_routes (nframes_t nframes, nframes_t offset)
+Session::silent_process_routes (pframes_t nframes, bool& need_butler)
 {
 	bool record_active = actively_recording();
 	int  declick = get_transport_declick_required();
@@ -186,80 +190,56 @@ Session::silent_process_routes (nframes_t nframes, nframes_t offset)
 		/* force a declick out */
 		declick = -1;
 	}
-	
-	const nframes_t start_frame = _transport_frame;
-	const nframes_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 
-	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+	const framepos_t start_frame = _transport_frame;
+	const framepos_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 
-		int ret;
-
-		if ((*i)->is_hidden()) {
-			continue;
-		}
+	/* XXX this is hack to force use of the graph even if we are only
+	   using 1 thread. its needed because otherwise when we remove
+	   tracks, the graph never gets updated.
+	*/
+	if (1 || route_graph->threads_in_use() > 0) {
+		route_graph->silent_process_routes( nframes, start_frame, end_frame, record_active, rec_monitors, need_butler);
+	} else {
+		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-		if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, offset, record_active, rec_monitors)) < 0) {
-			
-			/* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
-			   and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
-			   call path, so make sure we release any outstanding locks here before we return failure.
-			*/
+			int ret;
 
-			boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-			for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
-				(*ids)->recover ();
+			if ((*i)->is_hidden()) {
+				continue;
 			}
 
-			stop_transport ();
-			return -1;
-		} 
+			if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, record_active, rec_monitors, need_butler)) < 0) {
+				stop_transport ();
+				return -1;
+			}
+		}
 	}
 
 	return 0;
 }
 
 void
-Session::commit_diskstreams (nframes_t nframes, bool &needs_butler)
+Session::get_track_statistics ()
 {
-	int dret;
 	float pworst = 1.0f;
 	float cworst = 1.0f;
 
-	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
+	boost::shared_ptr<RouteList> rl = routes.reader();
+	for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 
-		if ((*i)->hidden()) {
+		boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
+
+		if (!tr || tr->hidden()) {
 			continue;
 		}
-		
-		/* force all diskstreams not handled by a Route to call do their stuff.
-		   Note: the diskstreams that were handled by a route will just return zero
-		   from this call, because they know they were processed. So in fact, this
-		   also runs commit() for every diskstream.
-		 */
-
-		if ((dret = (*i)->process (_transport_frame, nframes, 0, actively_recording(), get_rec_monitors_input())) == 0) {
-			if ((*i)->commit (nframes)) {
-				needs_butler = true;
-			}
 
-		} else if (dret < 0) {
-			(*i)->recover();
-		}
-		
-		pworst = min (pworst, (*i)->playback_buffer_load());
-		cworst = min (cworst, (*i)->capture_buffer_load());
+		pworst = min (pworst, tr->playback_buffer_load());
+		cworst = min (cworst, tr->capture_buffer_load());
 	}
 
-	uint32_t pmin = g_atomic_int_get (&_playback_load);
-	uint32_t pminold = g_atomic_int_get (&_playback_load_min);
-	uint32_t cmin = g_atomic_int_get (&_capture_load);
-	uint32_t cminold = g_atomic_int_get (&_capture_load_min);
-
 	g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 	g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
-	g_atomic_int_set (&_playback_load_min, min (pmin, pminold));
-	g_atomic_int_set (&_capture_load_min, min (cmin, cminold));
 
 	if (actively_recording()) {
 		set_dirty();
@@ -268,20 +248,18 @@ Session::commit_diskstreams (nframes_t nframes, bool &needs_butler)
 
 /** Process callback used when the auditioner is not active */
 void
-Session::process_with_events (nframes_t nframes)
+Session::process_with_events (pframes_t nframes)
 {
-	Event*         ev;
-	nframes_t      this_nframes;
-	nframes_t      end_frame;
-	nframes_t      offset;
+	SessionEvent*  ev;
+	pframes_t      this_nframes;
+	framepos_t     end_frame;
 	bool           session_needs_butler = false;
-	nframes_t      stop_limit;
-	long           frames_moved;
-	
+	framecnt_t     frames_moved;
+
 	/* make sure the auditioner is silent */
 
 	if (auditioner) {
-		auditioner->silence (nframes, 0);
+		auditioner->silence (nframes);
 	}
 
 	/* handle any pending events */
@@ -292,21 +270,51 @@ Session::process_with_events (nframes_t nframes)
 
 	/* if we are not in the middle of a state change,
 	   and there are immediate events queued up,
-	   process them. 
+	   process them.
 	*/
 
 	while (!non_realtime_work_pending() && !immediate_events.empty()) {
-		Event *ev = immediate_events.front ();
+		SessionEvent *ev = immediate_events.front ();
 		immediate_events.pop_front ();
 		process_event (ev);
 	}
 
-	/* Events caused a transport change, send an MTC Full Frame (SMPTE) message.
-	 * This is sent whether rolling or not, to give slaves an idea of ardour time
-	 * on locates (and allow slow slaves to position and prepare for rolling)
+	/* Decide on what to do with quarter-frame MTC during this cycle */
+
+	bool const was_sending_qf_mtc = _send_qf_mtc;
+	double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
+
+	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 (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
+	 * ardour time on locates (and allow slow slaves to position
+	 * and prepare for rolling)
 	 */
-	if (_send_smpte_update) {
-		send_full_time_code(nframes);
+	if (_send_timecode_update) {
+		send_full_time_code (_transport_frame);
 	}
 
 	if (!process_can_proceed()) {
@@ -319,94 +327,80 @@ Session::process_with_events (nframes_t nframes)
 		return;
 	}
 
-	/// TODO: Figure out what happens to phi and phase, if transport speed momentarily becomes
-	/// 1.0 eg. during the adjustments of a slave. If that is a bug, then AudioDiskstream::process
-	/// is very likely broken too
 	if (_transport_speed == 1.0) {
-		frames_moved = (long) nframes;
-	} else {		
-		frames_moved = (long) AudioDiskstream::
-			calculate_varispeed_playback_distance(nframes, phase, phi, target_phi); 
+		frames_moved = (framecnt_t) nframes;
+	} else {
+		interpolation.set_target_speed (fabs(_target_transport_speed));
+		interpolation.set_speed (fabs(_transport_speed));
+		frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 	}
 
-	end_frame = _transport_frame + (nframes_t)frames_moved;
+	end_frame = _transport_frame + frames_moved;
 
 	{
-		Event* this_event;
+		SessionEvent* this_event;
 		Events::iterator the_next_one;
-		
+
 		if (!process_can_proceed()) {
 			_silent = true;
 			return;
 		}
-		
+
 		if (!_exporting && _slave) {
-			if (!follow_slave (nframes, 0)) {
+			if (!follow_slave (nframes)) {
 				return;
 			}
-		} 
+		}
 
 		if (_transport_speed == 0) {
-			no_roll (nframes, 0);
+			no_roll (nframes);
 			return;
 		}
-	
-		if (!_exporting) {
-			send_midi_time_code_for_cycle (nframes);
-		}
-
-		if (actively_recording()) {
-			stop_limit = max_frames;
-		} else {
 
-			if (Config->get_stop_at_session_end()) {
-				stop_limit = current_end_frame();
-			} else {
-				stop_limit = max_frames;
-			}
+		if (!_exporting && !timecode_transmission_suspended()) {
+			send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
 		}
 
+		framepos_t stop_limit = compute_stop_limit ();
+
 		if (maybe_stop (stop_limit)) {
-			no_roll (nframes, 0);
+			no_roll (nframes);
 			return;
-		} 
+		}
 
 		this_event = *next_event;
 		the_next_one = next_event;
 		++the_next_one;
 
-		offset = 0;
-
 		/* yes folks, here it is, the actual loop where we really truly
-		   process some audio */
+		   process some audio
+		*/
+
 		while (nframes) {
 
 			this_nframes = nframes; /* real (jack) time relative */
+			frames_moved = (framecnt_t) floor (_transport_speed * nframes); /* transport relative */
 
 			/* running an event, position transport precisely to its time */
 			if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 				/* this isn't quite right for reverse play */
-				frames_moved = (long) (this_event->action_frame - _transport_frame);
-				this_nframes = (nframes_t) abs( floor(frames_moved / _transport_speed) );
-			} 
+				frames_moved = (framecnt_t) (this_event->action_frame - _transport_frame);
+				this_nframes = abs (floor(frames_moved / _transport_speed));
+			}
 
 			if (this_nframes) {
-				
-				click (_transport_frame, nframes, offset);
-				
-				/* now process frames between now and the first event in this block */
-				prepare_diskstreams ();
-
-				if (process_routes (this_nframes, offset)) {
-					no_roll (nframes, 0);
+
+				click (_transport_frame, this_nframes);
+
+				if (process_routes (this_nframes, session_needs_butler)) {
+					fail_roll (nframes);
 					return;
 				}
-				
-				commit_diskstreams (this_nframes, session_needs_butler);
+
+				get_track_statistics ();
 
 				nframes -= this_nframes;
-				offset += this_nframes;
-				
+
 				if (frames_moved < 0) {
 					decrement_transport_position (-frames_moved);
 				} else {
@@ -417,8 +411,10 @@ Session::process_with_events (nframes_t nframes)
 				check_declick_out ();
 			}
 
+			_engine.split_cycle (this_nframes);
+
 			/* now handle this event and all others scheduled for the same time */
-			
+
 			while (this_event && this_event->action_frame == _transport_frame) {
 				process_event (this_event);
 
@@ -428,26 +424,26 @@ Session::process_with_events (nframes_t nframes)
 					this_event = *the_next_one;
 					++the_next_one;
 				}
-			} 
+			}
 
 			/* if an event left our state changing, do the right thing */
 
-			if (non_realtime_work_pending()) {
-				no_roll (nframes, offset);
+			if (nframes && non_realtime_work_pending()) {
+				no_roll (nframes);
 				break;
 			}
 
 			/* this is necessary to handle the case of seamless looping */
-			end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
-			
+			end_frame = _transport_frame + floor (nframes * _transport_speed);
 		}
 
 		set_next_event ();
 
 	} /* implicit release of route lock */
 
-	if (session_needs_butler)
-		summon_butler ();
+	if (session_needs_butler) {
+		_butler->summon ();
+	}
 }
 
 void
@@ -456,7 +452,7 @@ Session::reset_slave_state ()
 	average_slave_delta = 1800;
 	delta_accumulator_cnt = 0;
 	have_first_delta_accumulator = false;
-	slave_state = Stopped;
+	_slave_state = Stopped;
 }
 
 bool
@@ -464,7 +460,7 @@ Session::transport_locked () const
 {
 	Slave* sl = _slave;
 
-	if (!locate_pending() && ((Config->get_slave_source() == None) || (sl && sl->ok() && sl->locked()))) {
+	if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 		return true;
 	}
 
@@ -472,23 +468,25 @@ Session::transport_locked () const
 }
 
 bool
-Session::follow_slave (nframes_t nframes, nframes_t offset)
+Session::follow_slave (pframes_t nframes)
 {
 	double slave_speed;
-	nframes_t slave_transport_frame;
-	nframes_t this_delta;
+	framepos_t slave_transport_frame;
+	framecnt_t this_delta;
 	int dir;
-	bool starting;
 
 	if (!_slave->ok()) {
 		stop_transport ();
-		Config->set_slave_source (None);
+		config.set_external_sync (false);
 		goto noroll;
 	}
-	
+
 	_slave->speed_and_position (slave_speed, slave_transport_frame);
 
+	DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
+
 	if (!_slave->locked()) {
+		DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 		goto noroll;
 	}
 
@@ -500,111 +498,107 @@ Session::follow_slave (nframes_t nframes, nframes_t offset)
 		dir = -1;
 	}
 
-	if ((starting = _slave->starting())) {
+	if (_slave->starting()) {
 		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()) {
 
-		/* if the TC source is synced, then we assume that its 
+		/* if the TC source is synced, then we assume that its
 		   speed is binary: 0.0 or 1.0
 		*/
 
 		if (slave_speed != 0.0f) {
 			slave_speed = 1.0f;
-		} 
+		}
 
 	} else {
 
-		/* TC source is able to drift relative to us (slave)
-		   so we need to keep track of the drift and adjust
-		   our speed to remain locked.
+		/* if we are chasing and the average delta between us and the
+		   master gets too big, we want to switch to silent
+		   motion. so keep track of that here.
 		*/
 
-		calculate_moving_average_of_slave_delta(dir, this_delta);
+		if (_slave_state == Running) {
+			calculate_moving_average_of_slave_delta(dir, this_delta);
+		}
 	}
-	
-	track_slave_state(slave_speed, slave_transport_frame, this_delta, starting);
 
-	if (slave_state == Running && !_slave->is_always_synced() && !Config->get_timecode_source_is_synced()) {
+	track_slave_state (slave_speed, slave_transport_frame, this_delta);
+
+	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 (_transport_speed != 0.0f) {
-			
-			/* 
-			   note that average_dir is +1 or -1 
+
+			/*
+			   note that average_dir is +1 or -1
 			*/
-			
+
 			float delta;
 
-			#ifdef USE_MOVING_AVERAGE_OF_SLAVE
-				if (average_slave_delta == 0) {
-					delta = this_delta;
-					delta *= dir;
-				} else {
-					delta = average_slave_delta;
-					delta *= average_dir;
-				}
-			#else
+			if (average_slave_delta == 0) {
 				delta = this_delta;
 				delta *= dir;
-			#endif
+			} else {
+				delta = average_slave_delta;
+				delta *= average_dir;
+			}
+
+#ifndef NDEBUG
+			if (slave_speed != 0.0) {
+				DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
+									   (int) (dir * this_delta),
+									   slave_speed,
+									   _transport_speed,
+									   _transport_frame,
+									   slave_transport_frame,
+									   average_slave_delta));
+			}
+#endif
 
-			float adjusted_speed = slave_speed + (delta /  float(_current_frame_rate));
-			
 			if (_slave->give_slave_full_control_over_transport_speed()) {
-				request_transport_speed(slave_speed);
+				set_transport_speed (slave_speed, false, false);
+				//std::cout << "set speed = " << slave_speed << "\n";
 			} else {
-				request_transport_speed(adjusted_speed);
-				#ifdef DEBUG_SLAVES
-				cerr << "adjust using " << delta
-					 << " towards " << adjusted_speed
-					 << " ratio = " << adjusted_speed / slave_speed
-					 << " current = " << _transport_speed
-					 << " slave @ " << slave_speed
-					 << endl;
-				#endif
+				float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
+				request_transport_speed (adjusted_speed);
+				DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
+									   delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
+									   slave_speed));
 			}
-			
-			if (abs(average_slave_delta) > (long) _slave->resolution()) {
-				cerr << "average slave delta greater than slave resolution, going to silent motion\n";
+
+#if 1
+			if ((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;
 			}
+#endif
 		}
-	} 
-	
-	#ifdef DEBUG_SLAVES
-	if (slave_speed != 0.0)
-	cerr << "delta = " << (int) (dir * this_delta)
-		 << " speed = " << slave_speed 
-		 << " ts = " << _transport_speed 
-		 << " M@ "<< slave_transport_frame << " S@ " << _transport_frame 
-		 << " avgdelta = " << average_slave_delta 
-		 << endl;
-	#endif	
-
-	if (!starting && !non_realtime_work_pending()) {
+	}
+
+
+	if (_slave_state == Running && !non_realtime_work_pending()) {
 		/* speed is set, we're locked, and good to go */
 		return true;
 	}
 
   silent_motion:
-	#ifdef DEBUG_SLAVES	
-	cerr << "reached silent_motion:" <<endl;
-	#endif
-	
-	follow_slave_silently(nframes, offset, slave_speed);
-	
+	DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
+	follow_slave_silently (nframes, slave_speed);
+
   noroll:
 	/* don't move at all */
-	#ifdef DEBUG_SLAVES	
-	cerr << "reached no_roll:" <<endl;
-	#endif
-	no_roll (nframes, 0);
+	DEBUG_TRACE (DEBUG::Slave, "no roll\n")
+	no_roll (nframes);
 	return false;
 }
 
 void
-Session::calculate_moving_average_of_slave_delta(int dir, nframes_t this_delta)
+Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta)
 {
 	if (delta_accumulator_cnt >= delta_accumulator_size) {
 		have_first_delta_accumulator = true;
@@ -612,15 +606,15 @@ Session::calculate_moving_average_of_slave_delta(int dir, nframes_t this_delta)
 	}
 
 	if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
-		delta_accumulator[delta_accumulator_cnt++] = long(dir) * long(this_delta);
+		delta_accumulator[delta_accumulator_cnt++] = (framecnt_t) dir *  (framecnt_t) this_delta;
 	}
-	
+
 	if (have_first_delta_accumulator) {
 		average_slave_delta = 0L;
 		for (int i = 0; i < delta_accumulator_size; ++i) {
 			average_slave_delta += delta_accumulator[i];
 		}
-		average_slave_delta /= long(delta_accumulator_size);
+		average_slave_delta /= (int32_t) delta_accumulator_size;
 		if (average_slave_delta < 0L) {
 			average_dir = -1;
 			average_slave_delta = abs(average_slave_delta);
@@ -631,29 +625,26 @@ Session::calculate_moving_average_of_slave_delta(int dir, nframes_t this_delta)
 }
 
 void
-Session::track_slave_state(
-		float slave_speed, 
-		nframes_t slave_transport_frame, 
-		nframes_t this_delta,
-		bool starting)
+Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t this_delta)
 {
 	if (slave_speed != 0.0f) {
 
 		/* slave is running */
 
-		switch (slave_state) {
+		switch (_slave_state) {
 		case Stopped:
 			if (_slave->requires_seekahead()) {
-				slave_wait_end = slave_transport_frame + _current_frame_rate;
+				slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
+				DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
+				/* we can call locate() here because we are in process context */
 				locate (slave_wait_end, false, false);
-				slave_state = Waiting;
-				starting = true;
+				_slave_state = Waiting;
 
 			} else {
 
-				slave_state = Running;
+				_slave_state = Running;
 
-				Location* al = _locations.auto_loop_location();
+				Location* al = _locations->auto_loop_location();
 
 				if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 					// cancel looping
@@ -667,88 +658,82 @@ Session::track_slave_state(
 			break;
 
 		case Waiting:
-			break;
-
 		default:
 			break;
-
 		}
 
-		if (slave_state == Waiting) {
+		if (_slave_state == Waiting) {
+
+			DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 
-		#ifdef DEBUG_SLAVES
-			cerr << "waiting at " << slave_transport_frame << endl;
-		#endif			
 			if (slave_transport_frame >= slave_wait_end) {
-#ifdef DEBUG_SLAVES
-				cerr << "\tstart at " << _transport_frame << endl;
-#endif
-				slave_state = Running;
+
+				DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
+
+				_slave_state = Running;
+
+				/* now perform a "micro-seek" within the disk buffers to realign ourselves
+				   precisely with the master.
+				*/
+
 
 				bool ok = true;
-				nframes_t frame_delta = slave_transport_frame - _transport_frame;
+				framecnt_t frame_delta = slave_transport_frame - _transport_frame;
 
-				boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-				
-				for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
-					if (!(*i)->can_internal_playback_seek (frame_delta)) {
+				boost::shared_ptr<RouteList> rl = routes.reader();
+				for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
+					boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
+					if (tr && !tr->can_internal_playback_seek (frame_delta)) {
 						ok = false;
 						break;
 					}
 				}
 
 				if (ok) {
-					for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
-						(*i)->internal_playback_seek (frame_delta);
+					for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
+						boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
+						if (tr) {
+							tr->internal_playback_seek (frame_delta);
+						}
 					}
 					_transport_frame += frame_delta;
-				       
+
 				} else {
 					cerr << "cannot micro-seek\n";
 					/* XXX what? */
 				}
 
-				memset (delta_accumulator, 0, sizeof (long) * delta_accumulator_size);
+				memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 				average_slave_delta = 0L;
 				this_delta = 0;
 			}
 		}
-		
-		if (slave_state == Running && _transport_speed == 0.0f) {
-			
-        #ifdef DEBUG_SLAVES
-			cerr << "slave starts transport\n";
-        #endif
+
+		if (_slave_state == Running && _transport_speed == 0.0f) {
+			DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 			start_transport ();
-		} 
+		}
 
 	} else { // slave_speed is 0
 
 		/* slave has stopped */
 
 		if (_transport_speed != 0.0f) {
-
-         #ifdef DEBUG_SLAVES
-			cerr << "slave stops transport: " << slave_speed << " frame: " << slave_transport_frame 
-			     << " tf = " << _transport_frame << endl;
-         #endif
-			
-			stop_transport();
+			DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
+			stop_transport ();
 		}
 
 		if (slave_transport_frame != _transport_frame) {
-        #ifdef DEBUG_SLAVES			
-			cerr << "slave stopped, move to " << slave_transport_frame << endl;
-        #endif
+			DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 			force_locate (slave_transport_frame, false);
 		}
 
-		slave_state = Stopped;
+		_slave_state = Stopped;
 	}
 }
 
 void
-Session::follow_slave_silently(nframes_t nframes, nframes_t offset, float slave_speed)
+Session::follow_slave_silently (pframes_t nframes, float slave_speed)
 {
 	if (slave_speed && _transport_speed) {
 
@@ -757,46 +742,33 @@ Session::follow_slave_silently(nframes_t nframes, nframes_t offset, float slave_
 		*/
 
 		bool need_butler;
-		
-		prepare_diskstreams ();
-		silent_process_routes (nframes, offset);
-		commit_diskstreams (nframes, need_butler);
+
+		silent_process_routes (nframes, need_butler);
+
+		get_track_statistics ();
 
 		if (need_butler) {
-			summon_butler ();
+			_butler->summon ();
 		}
-		
+
 		int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
-		
+
 		if (frames_moved < 0) {
 			decrement_transport_position (-frames_moved);
 		} else {
 			increment_transport_position (frames_moved);
 		}
-		
-		nframes_t stop_limit;
-		
-		if (actively_recording()) {
-			stop_limit = max_frames;
-		} else {
-			if (Config->get_stop_at_session_end()) {
-				stop_limit = current_end_frame();
-			} else {
-				stop_limit = max_frames;
-			}
-		}
 
+		framepos_t const stop_limit = compute_stop_limit ();
 		maybe_stop (stop_limit);
 	}
 }
 
 void
-Session::process_without_events (nframes_t nframes)
+Session::process_without_events (pframes_t nframes)
 {
 	bool session_needs_butler = false;
-	nframes_t stop_limit;
-	long frames_moved;
-	nframes_t offset = 0;
+	framecnt_t frames_moved;
 
 	if (!process_can_proceed()) {
 		_silent = true;
@@ -804,59 +776,57 @@ Session::process_without_events (nframes_t nframes)
 	}
 
 	if (!_exporting && _slave) {
-		if (!follow_slave (nframes, 0)) {
+		if (!follow_slave (nframes)) {
 			return;
 		}
-	} 
+	}
 
 	if (_transport_speed == 0) {
-		no_roll (nframes, 0);
+		fail_roll (nframes);
 		return;
 	}
-		
-	if (!_exporting) {
-		send_midi_time_code_for_cycle (nframes);
-	}
 
-	if (actively_recording()) {
-		stop_limit = max_frames;
+	if (_transport_speed == 1.0) {
+		frames_moved = (framecnt_t) nframes;
 	} else {
-		if (Config->get_stop_at_session_end()) {
-			stop_limit = current_end_frame();
-		} else {
-			stop_limit = max_frames;
-		}
+		interpolation.set_target_speed (fabs(_target_transport_speed));
+		interpolation.set_speed (fabs(_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);
+	}
+
+	framepos_t const stop_limit = compute_stop_limit ();
+
 	if (maybe_stop (stop_limit)) {
-		no_roll (nframes, 0);
+		fail_roll (nframes);
 		return;
-	} 
+	}
 
-	if (maybe_sync_start (nframes, offset)) {
+	if (maybe_sync_start (nframes)) {
 		return;
 	}
 
-	click (_transport_frame, nframes, offset);
+	click (_transport_frame, nframes);
 
-	prepare_diskstreams ();
-	
-	/// TODO: Figure out what happens to phi and phase, if transport speed momentarily becomes
-	/// 1.0 eg. during the adjustments of a slave. If that is a bug, then AudioDiskstream::process
-	/// is very likely broken too
-	if (_transport_speed == 1.0) {
-		frames_moved = (long) nframes;
-	} else {		
-		frames_moved = (long) AudioDiskstream::
-			calculate_varispeed_playback_distance(nframes, phase, phi, target_phi); 
-	}
-
-	if (process_routes (nframes, offset)) {
-		no_roll (nframes, offset);
+	if (process_routes (nframes, session_needs_butler)) {
+		fail_roll (nframes);
 		return;
 	}
 
-	commit_diskstreams (nframes, session_needs_butler);
+	get_track_statistics ();
+
+	/* XXX: I'm not sure whether this is correct, but at least it
+	   matches process_with_events, so that this new frames_moved
+	   is -ve when transport speed is -ve.  This means that the
+	   transport position is updated correctly when we are in
+	   reverse.  It seems a bit wrong that we're not using the
+	   interpolator to compute this.
+	*/
+
+	frames_moved = (framecnt_t) floor (_transport_speed * nframes);
 
 	if (frames_moved < 0) {
 		decrement_transport_position (-frames_moved);
@@ -867,30 +837,37 @@ Session::process_without_events (nframes_t nframes)
 	maybe_stop (stop_limit);
 	check_declick_out ();
 
-	if (session_needs_butler)
-		summon_butler ();
+	if (session_needs_butler) {
+		_butler->summon ();
+	}
 }
 
 /** Process callback used when the auditioner is active.
  * @param nframes number of frames to process.
  */
 void
-Session::process_audition (nframes_t nframes)
+Session::process_audition (pframes_t nframes)
 {
-	Event* ev;
+	SessionEvent* ev;
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		if (!(*i)->is_hidden()) {
-			(*i)->silence (nframes, 0);
+			(*i)->silence (nframes);
 		}
 	}
 
 	/* run the auditioner, and if it says we need butler service, ask for it */
-	
+
 	if (auditioner->play_audition (nframes) > 0) {
-		summon_butler ();
-	} 
+		_butler->summon ();
+	}
+
+	/* if using a monitor section, run it because otherwise we don't hear anything */
+
+	if (auditioner->needs_monitor()) {
+		_monitor_out->passthru (_transport_frame, _transport_frame + nframes, nframes, false);
+	}
 
 	/* handle pending events */
 
@@ -900,25 +877,25 @@ Session::process_audition (nframes_t nframes)
 
 	/* if we are not in the middle of a state change,
 	   and there are immediate events queued up,
-	   process them. 
+	   process them.
 	*/
 
 	while (!non_realtime_work_pending() && !immediate_events.empty()) {
-		Event *ev = immediate_events.front ();
+		SessionEvent *ev = immediate_events.front ();
 		immediate_events.pop_front ();
 		process_event (ev);
 	}
 
-	if (!auditioner->active()) {
+	if (!auditioner->auditioning()) {
 		/* auditioner no longer active, so go back to the normal process callback */
 		process_function = &Session::process_with_events;
 	}
 }
 
 bool
-Session::maybe_sync_start (nframes_t& nframes, nframes_t& offset)
+Session::maybe_sync_start (pframes_t & nframes)
 {
-	nframes_t sync_offset;
+	pframes_t sync_offset;
 
 	if (!waiting_for_sync_offset) {
 		return false;
@@ -931,25 +908,23 @@ Session::maybe_sync_start (nframes_t& nframes, nframes_t& offset)
 		   is left to do.
 		*/
 
-		no_roll (sync_offset, 0);
+		no_roll (sync_offset);
 		nframes -= sync_offset;
-		offset += sync_offset;
+		Port::increment_global_port_buffer_offset (sync_offset);
 		waiting_for_sync_offset = false;
-		
+
 		if (nframes == 0) {
 			return true; // done, nothing left to process
 		}
-		
+
 	} else {
 
 		/* sync offset point is not within this process()
-		   cycle, so just generate silence. and don't bother 
+		   cycle, so just generate silence. and don't bother
 		   with any fancy stuff here, just the minimal silence.
 		*/
 
-		g_atomic_int_inc (&processing_prohibited);
-		no_roll (nframes, 0);
-		g_atomic_int_dec_and_test (&processing_prohibited);
+		_silent = true;
 
 		if (Config->get_locate_while_waiting_for_sync()) {
 			if (micro_locate (nframes)) {
@@ -963,3 +938,220 @@ Session::maybe_sync_start (nframes_t& nframes, nframes_t& offset)
 	return false;
 }
 
+void
+Session::queue_event (SessionEvent* ev)
+{
+	if (_state_of_the_state & Deletion) {
+		return;
+	} else if (_state_of_the_state & Loading) {
+		merge_event (ev);
+	} else {
+		pending_events.write (&ev, 1);
+	}
+}
+
+void
+Session::set_next_event ()
+{
+	if (events.empty()) {
+		next_event = events.end();
+		return;
+	}
+
+	if (next_event == events.end()) {
+		next_event = events.begin();
+	}
+
+	if ((*next_event)->action_frame > _transport_frame) {
+		next_event = events.begin();
+	}
+
+	for (; next_event != events.end(); ++next_event) {
+		if ((*next_event)->action_frame >= _transport_frame) {
+			break;
+		}
+	}
+}
+
+void
+Session::process_event (SessionEvent* ev)
+{
+	bool remove = true;
+	bool del = true;
+
+	/* if we're in the middle of a state change (i.e. waiting
+	   for the butler thread to complete the non-realtime
+	   part of the change), we'll just have to queue this
+	   event for a time when the change is complete.
+	*/
+
+	if (non_realtime_work_pending()) {
+
+		/* except locates, which we have the capability to handle */
+
+		if (ev->type != SessionEvent::Locate) {
+			immediate_events.insert (immediate_events.end(), ev);
+			_remove_event (ev);
+			return;
+		}
+	}
+
+	DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
+
+	switch (ev->type) {
+	case SessionEvent::SetLoop:
+		set_play_loop (ev->yes_or_no);
+		break;
+
+	case SessionEvent::AutoLoop:
+		if (play_loop) {
+			start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
+		}
+		remove = false;
+		del = false;
+		break;
+
+	case SessionEvent::Locate:
+		if (ev->yes_or_no) {
+			// cerr << "forced locate to " << ev->target_frame << endl;
+			locate (ev->target_frame, false, true, false);
+		} else {
+			// cerr << "soft locate to " << ev->target_frame << endl;
+			start_locate (ev->target_frame, false, true, false);
+		}
+		_send_timecode_update = true;
+		break;
+
+	case SessionEvent::LocateRoll:
+		if (ev->yes_or_no) {
+			// cerr << "forced locate to+roll " << ev->target_frame << endl;
+			locate (ev->target_frame, true, true, false);
+		} else {
+			// cerr << "soft locate to+roll " << ev->target_frame << endl;
+			start_locate (ev->target_frame, true, true, false);
+		}
+		_send_timecode_update = true;
+		break;
+
+	case SessionEvent::LocateRollLocate:
+		// locate is handled by ::request_roll_at_and_return()
+		_requested_return_frame = ev->target_frame;
+		request_locate (ev->target2_frame, true);
+		break;
+
+
+	case SessionEvent::SetTransportSpeed:
+		set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no);
+		break;
+
+	case SessionEvent::PunchIn:
+		// cerr << "PunchIN at " << transport_frame() << endl;
+		if (config.get_punch_in() && record_status() == Enabled) {
+			enable_record ();
+		}
+		remove = false;
+		del = false;
+		break;
+
+	case SessionEvent::PunchOut:
+		// cerr << "PunchOUT at " << transport_frame() << endl;
+		if (config.get_punch_out()) {
+			step_back_from_record ();
+		}
+		remove = false;
+		del = false;
+		break;
+
+	case SessionEvent::StopOnce:
+		if (!non_realtime_work_pending()) {
+			stop_transport (ev->yes_or_no);
+			_clear_event_type (SessionEvent::StopOnce);
+		}
+		remove = false;
+		del = false;
+		break;
+
+	case SessionEvent::RangeStop:
+		if (!non_realtime_work_pending()) {
+			stop_transport (ev->yes_or_no);
+		}
+		remove = false;
+		del = false;
+		break;
+
+	case SessionEvent::RangeLocate:
+		start_locate (ev->target_frame, true, true, false);
+		remove = false;
+		del = false;
+		break;
+
+	case SessionEvent::Overwrite:
+		overwrite_some_buffers (static_cast<Track*>(ev->ptr));
+		break;
+
+	case SessionEvent::SetTrackSpeed:
+		set_track_speed (static_cast<Track*> (ev->ptr), ev->speed);
+		break;
+
+	case SessionEvent::SetSyncSource:
+		use_sync_source (ev->slave);
+		break;
+
+	case SessionEvent::Audition:
+		set_audition (ev->region);
+		// drop reference to region
+		ev->region.reset ();
+		break;
+
+	case SessionEvent::InputConfigurationChange:
+		add_post_transport_work (PostTransportInputChange);
+		_butler->schedule_transport_work ();
+		break;
+
+	case SessionEvent::SetPlayAudioRange:
+		set_play_range (ev->audio_range, (ev->speed == 1.0f));
+		break;
+
+	case SessionEvent::RealTimeOperation:
+		process_rtop (ev);
+		del = false; // other side of RT request needs to clean up
+		break;
+
+	case SessionEvent::AdjustPlaybackBuffering:
+		schedule_playback_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);
+		break;
+
+	default:
+	  fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
+		/*NOTREACHED*/
+		break;
+	};
+
+	if (remove) {
+		del = del && !_remove_event (ev);
+	}
+
+	if (del) {
+		delete ev;
+	}
+}
+
+framepos_t
+Session::compute_stop_limit () const
+{
+	bool const punching = (config.get_punch_in () && _locations->auto_punch_location());
+
+	if (!actively_recording() && !punching && Config->get_stop_at_session_end()) {
+		return current_end_frame ();
+	}
+
+	return max_framepos;
+}