libs/ardour/session_process.cc

   1 /*
   2     Copyright (C) 1999-2002 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include <cmath>
  21 #include <cerrno>
  22 #include <algorithm>
  23 #include <unistd.h>
  24
  25 #include "pbd/error.h"
  26 #include "pbd/enumwriter.h"
  27
  28 #include <glibmm/threads.h>
  29
  30 #include "ardour/audioengine.h"
  31 #include "ardour/auditioner.h"
  32 #include "ardour/butler.h"
  33 #include "ardour/cycle_timer.h"
  34 #include "ardour/debug.h"
  35 #include "ardour/disk_reader.h"
  36 #include "ardour/graph.h"
  37 #include "ardour/port.h"
  38 #include "ardour/process_thread.h"
  39 #include "ardour/scene_changer.h"
  40 #include "ardour/session.h"
  41 #include "ardour/slave.h"
  42 #include "ardour/ticker.h"
  43 #include "ardour/types.h"
  44 #include "ardour/vca.h"
  45 #include "ardour/vca_manager.h"
  46
  47 #include "midi++/mmc.h"
  48
  49 #include "pbd/i18n.h"
  50
  51 using namespace ARDOUR;
  52 using namespace PBD;
  53 using namespace std;
  54
  55 /** Called by the audio engine when there is work to be done with JACK.
  56  * @param nframes Number of frames to process.
  57  */
  58
  59 void
  60 Session::process (pframes_t nframes)
  61 {
  62         framepos_t transport_at_start = _transport_frame;
  63
  64         _silent = false;
  65
  66         if (processing_blocked()) {
  67                 _silent = true;
  68                 return;
  69         }
  70
  71         if (non_realtime_work_pending()) {
  72                 if (!_butler->transport_work_requested ()) {
  73                         post_transport ();
  74                 }
  75         }
  76
  77         _engine.main_thread()->get_buffers ();
  78
  79         (this->*process_function) (nframes);
  80
  81         /* realtime-safe meter-position and processor-order changes
  82          *
  83          * ideally this would be done in
  84          * Route::process_output_buffers() but various functions
  85          * callig it hold a _processor_lock reader-lock
  86          */
  87         boost::shared_ptr<RouteList> r = routes.reader ();
  88         for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
  89                 if ((*i)->apply_processor_changes_rt()) {
  90                         _rt_emit_pending = true;
  91                 }
  92         }
  93         if (_rt_emit_pending) {
  94                 if (!_rt_thread_active) {
  95                         emit_route_signals ();
  96                 }
  97                 if (pthread_mutex_trylock (&_rt_emit_mutex) == 0) {
  98                         pthread_cond_signal (&_rt_emit_cond);
  99                         pthread_mutex_unlock (&_rt_emit_mutex);
 100                         _rt_emit_pending = false;
 101                 }
 102         }
 103
 104         _engine.main_thread()->drop_buffers ();
 105
 106         /* deliver MIDI clock. Note that we need to use the transport frame
 107          * position at the start of process(), not the value at the end of
 108          * it. We may already have ticked() because of a transport state
 109          * change, for example.
 110          */
 111
 112         try {
 113                 if (!_silent && !_engine.freewheeling() && Config->get_send_midi_clock() && (transport_speed() == 1.0f || transport_speed() == 0.0f) && midi_clock->has_midi_port()) {
 114                         midi_clock->tick (transport_at_start, nframes);
 115                 }
 116
 117                 _scene_changer->run (transport_at_start, transport_at_start + nframes);
 118
 119         } catch (...) {
 120                 /* don't bother with a message */
 121         }
 122
 123         SendFeedback (); /* EMIT SIGNAL */
 124 }
 125
 126 int
 127 Session::fail_roll (pframes_t nframes)
 128 {
 129         return no_roll (nframes);
 130 }
 131
 132 int
 133 Session::no_roll (pframes_t nframes)
 134 {
 135         PT_TIMING_CHECK (4);
 136
 137         framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
 138         int ret = 0;
 139         int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
 140         boost::shared_ptr<RouteList> r = routes.reader ();
 141
 142         if (_click_io) {
 143                 _click_io->silence (nframes);
 144         }
 145
 146         ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 147
 148         VCAList v = _vca_manager->vcas ();
 149         for (VCAList::const_iterator i = v.begin(); i != v.end(); ++i) {
 150                 (*i)->automation_run (_transport_frame, nframes);
 151         }
 152
 153         if (_process_graph) {
 154                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
 155                 _process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
 156         } else {
 157                 PT_TIMING_CHECK (10);
 158                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 159
 160                         if ((*i)->is_auditioner()) {
 161                                 continue;
 162                         }
 163
 164                         (*i)->set_pending_declick (declick);
 165
 166                         if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending())) {
 167                                 error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 168                                 ret = -1;
 169                                 break;
 170                         }
 171                 }
 172                 PT_TIMING_CHECK (11);
 173         }
 174
 175         PT_TIMING_CHECK (5);
 176         return ret;
 177 }
 178
 179 /** @param need_butler to be set to true by this method if it needs the butler,
 180  *  otherwise it must be left alone.
 181  */
 182 int
 183 Session::process_routes (pframes_t nframes, bool& need_butler)
 184 {
 185         int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
 186         boost::shared_ptr<RouteList> r = routes.reader ();
 187
 188         const framepos_t start_frame = _transport_frame;
 189         const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
 190
 191         VCAList v = _vca_manager->vcas ();
 192         for (VCAList::const_iterator i = v.begin(); i != v.end(); ++i) {
 193                 (*i)->automation_run (start_frame, nframes);
 194         }
 195
 196         _global_locate_pending = locate_pending ();
 197
 198         if (_process_graph) {
 199                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
 200                 if (_process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler) < 0) {
 201                         stop_transport ();
 202                         return -1;
 203                 }
 204         } else {
 205
 206                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 207
 208                         int ret;
 209
 210                         if ((*i)->is_auditioner()) {
 211                                 continue;
 212                         }
 213
 214                         (*i)->set_pending_declick (declick);
 215
 216                         bool b = false;
 217
 218                         if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, b)) < 0) {
 219                                 stop_transport ();
 220                                 return -1;
 221                         }
 222
 223                         if (b) {
 224                                 DEBUG_TRACE (DEBUG::Butler, string_compose ("%1 rolled and needs butler\n", (*i)->name()));
 225                                 need_butler = true;
 226                         }
 227                 }
 228         }
 229
 230         return 0;
 231 }
 232
 233 void
 234 Session::get_track_statistics ()
 235 {
 236         float pworst = 1.0f;
 237         float cworst = 1.0f;
 238
 239         boost::shared_ptr<RouteList> rl = routes.reader();
 240         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 241
 242                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 243
 244                 if (!tr || tr->is_private_route()) {
 245                         continue;
 246                 }
 247
 248                 pworst = min (pworst, tr->playback_buffer_load());
 249                 cworst = min (cworst, tr->capture_buffer_load());
 250         }
 251
 252         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 253         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 254
 255         if (actively_recording()) {
 256                 set_dirty();
 257         }
 258 }
 259
 260 /** Process callback used when the auditioner is not active */
 261 void
 262 Session::process_with_events (pframes_t nframes)
 263 {
 264         PT_TIMING_CHECK (3);
 265
 266         SessionEvent*  ev;
 267         pframes_t      this_nframes;
 268         framepos_t     end_frame;
 269         bool           session_needs_butler = false;
 270         framecnt_t     frames_moved;
 271
 272         /* make sure the auditioner is silent */
 273
 274         if (auditioner) {
 275                 auditioner->silence (nframes);
 276         }
 277
 278         /* handle any pending events */
 279
 280         while (pending_events.read (&ev, 1) == 1) {
 281                 merge_event (ev);
 282         }
 283
 284         /* if we are not in the middle of a state change,
 285            and there are immediate events queued up,
 286            process them.
 287         */
 288
 289         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 290                 SessionEvent *ev = immediate_events.front ();
 291                 immediate_events.pop_front ();
 292                 process_event (ev);
 293         }
 294
 295         /* count in */
 296         if (_transport_speed != 1.0 && _count_in_samples > 0) {
 297                 _count_in_samples = 0;
 298         }
 299
 300         if (_count_in_samples > 0) {
 301                 framecnt_t ns = std::min ((framecnt_t)nframes, _count_in_samples);
 302
 303                 no_roll (ns);
 304                 run_click (_transport_frame - _count_in_samples, ns);
 305
 306                 _count_in_samples -= ns;
 307                 nframes -= ns;
 308
 309                 /* process events.. */
 310                 if (!events.empty() && next_event != events.end()) {
 311                         SessionEvent* this_event = *next_event;
 312                         Events::iterator the_next_one = next_event;
 313                         ++the_next_one;
 314
 315                         while (this_event && this_event->action_frame == _transport_frame) {
 316                                 process_event (this_event);
 317                                 if (the_next_one == events.end()) {
 318                                         this_event = 0;
 319                                 } else {
 320                                         this_event = *the_next_one;
 321                                         ++the_next_one;
 322                                 }
 323                         }
 324                         set_next_event ();
 325                 }
 326
 327                 check_declick_out ();
 328
 329                 if (nframes == 0) {
 330                         return;
 331                 } else {
 332                         _engine.split_cycle (ns);
 333                 }
 334         }
 335
 336         /* Decide on what to do with quarter-frame MTC during this cycle */
 337
 338         bool const was_sending_qf_mtc = _send_qf_mtc;
 339         double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
 340
 341         if (_transport_speed != 0) {
 342                 _send_qf_mtc = (
 343                         Config->get_send_mtc () &&
 344                         _transport_speed >= (1 - tolerance) &&
 345                         _transport_speed <= (1 + tolerance)
 346                         );
 347
 348                 if (_send_qf_mtc && !was_sending_qf_mtc) {
 349                         /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
 350                         _send_timecode_update = true;
 351                 }
 352
 353                 if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
 354                         /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
 355                            a quarter of a second since we sent anything at all, so send a full MTC update
 356                            this cycle.
 357                         */
 358                         _send_timecode_update = true;
 359                 }
 360
 361                 _pframes_since_last_mtc += nframes;
 362         }
 363
 364         /* Events caused a transport change (or we re-started sending
 365          * MTC), so send an MTC Full Frame (Timecode) message.  This
 366          * is sent whether rolling or not, to give slaves an idea of
 367          * ardour time on locates (and allow slow slaves to position
 368          * and prepare for rolling)
 369          */
 370         if (_send_timecode_update) {
 371                 send_full_time_code (_transport_frame, nframes);
 372         }
 373
 374         if (!process_can_proceed()) {
 375                 _silent = true;
 376                 return;
 377         }
 378
 379         if (events.empty() || next_event == events.end()) {
 380                 try_run_lua (nframes); // also during export ?? ->move to process_without_events()
 381                 /* lua scripts may inject events */
 382                 while (_n_lua_scripts > 0 && pending_events.read (&ev, 1) == 1) {
 383                         merge_event (ev);
 384                 }
 385                 if (events.empty() || next_event == events.end()) {
 386                         process_without_events (nframes);
 387                         return;
 388                 }
 389         }
 390
 391         if (locate_pending()) {
 392                 frames_moved = 0;
 393         } else {
 394                 if (_transport_speed == 1.0) {
 395                         frames_moved = (framecnt_t) nframes;
 396                 } else {
 397                         interpolation.set_target_speed (_target_transport_speed);
 398                         interpolation.set_speed (_transport_speed);
 399                         frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 400                 }
 401         }
 402
 403         end_frame = _transport_frame + frames_moved;
 404
 405         {
 406                 SessionEvent* this_event;
 407                 Events::iterator the_next_one;
 408
 409                 if (!process_can_proceed()) {
 410                         _silent = true;
 411                         return;
 412                 }
 413
 414                 if (!_exporting && _slave) {
 415                         if (!follow_slave (nframes)) {
 416                                 return;
 417                         }
 418                 }
 419
 420                 if (_transport_speed == 0) {
 421                         no_roll (nframes);
 422                         return;
 423                 }
 424
 425                 if (!_exporting && !timecode_transmission_suspended()) {
 426                         send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
 427                 }
 428
 429                 ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 430
 431                 framepos_t stop_limit = compute_stop_limit ();
 432
 433                 if (maybe_stop (stop_limit)) {
 434                         no_roll (nframes);
 435                         return;
 436                 }
 437
 438                 this_event = *next_event;
 439                 the_next_one = next_event;
 440                 ++the_next_one;
 441
 442                 /* yes folks, here it is, the actual loop where we really truly
 443                    process some audio
 444                 */
 445
 446                 while (nframes) {
 447
 448                         this_nframes = nframes; /* real (jack) time relative */
 449                         if (locate_pending()) {
 450                                 frames_moved = 0;
 451                         } else {
 452                                 frames_moved = (framecnt_t) floor (_transport_speed * nframes); /* transport relative */
 453                         }
 454
 455                         /* running an event, position transport precisely to its time */
 456                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 457                                 /* this isn't quite right for reverse play */
 458                                 frames_moved = (framecnt_t) (this_event->action_frame - _transport_frame);
 459                                 this_nframes = abs (floor(frames_moved / _transport_speed));
 460                         }
 461
 462                         try_run_lua (this_nframes);
 463
 464                         if (this_nframes) {
 465
 466                                 click (_transport_frame, this_nframes);
 467
 468                                 if (process_routes (this_nframes, session_needs_butler)) {
 469                                         fail_roll (nframes);
 470                                         return;
 471                                 }
 472
 473                                 get_track_statistics ();
 474
 475                                 nframes -= this_nframes;
 476
 477                                 if (frames_moved < 0) {
 478                                         decrement_transport_position (-frames_moved);
 479                                 } else if (frames_moved) {
 480                                         increment_transport_position (frames_moved);
 481                                 }
 482
 483                                 maybe_stop (stop_limit);
 484                                 check_declick_out ();
 485                         }
 486
 487                         if (nframes > 0) {
 488                                 _engine.split_cycle (this_nframes);
 489                         }
 490
 491                         /* now handle this event and all others scheduled for the same time */
 492
 493                         while (this_event && this_event->action_frame == _transport_frame) {
 494                                 process_event (this_event);
 495
 496                                 if (the_next_one == events.end()) {
 497                                         this_event = 0;
 498                                 } else {
 499                                         this_event = *the_next_one;
 500                                         ++the_next_one;
 501                                 }
 502                         }
 503
 504                         /* if an event left our state changing, do the right thing */
 505
 506                         if (nframes && non_realtime_work_pending()) {
 507                                 no_roll (nframes);
 508                                 break;
 509                         }
 510
 511                         /* this is necessary to handle the case of seamless looping */
 512                         end_frame = _transport_frame + floor (nframes * _transport_speed);
 513                 }
 514
 515                 set_next_event ();
 516
 517         } /* implicit release of route lock */
 518
 519         if (session_needs_butler) {
 520                 DEBUG_TRACE (DEBUG::Butler, "p-with-events: session needs butler, call it\n");
 521                 _butler->summon ();
 522         }
 523 }
 524
 525 void
 526 Session::reset_slave_state ()
 527 {
 528         average_slave_delta = 1800;
 529         delta_accumulator_cnt = 0;
 530         have_first_delta_accumulator = false;
 531         _slave_state = Stopped;
 532 }
 533
 534 bool
 535 Session::transport_locked () const
 536 {
 537         Slave* sl = _slave;
 538
 539         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 540                 return true;
 541         }
 542
 543         return false;
 544 }
 545
 546 bool
 547 Session::follow_slave (pframes_t nframes)
 548 {
 549         double slave_speed;
 550         framepos_t slave_transport_frame;
 551         framecnt_t this_delta;
 552         int dir;
 553
 554         if (!_slave->ok()) {
 555                 stop_transport ();
 556                 config.set_external_sync (false);
 557                 goto noroll;
 558         }
 559
 560         _slave->speed_and_position (slave_speed, slave_transport_frame);
 561
 562         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 563
 564         if (!_slave->locked()) {
 565                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 566                 goto noroll;
 567         }
 568
 569         if (slave_transport_frame > _transport_frame) {
 570                 this_delta = slave_transport_frame - _transport_frame;
 571                 dir = 1;
 572         } else {
 573                 this_delta = _transport_frame - slave_transport_frame;
 574                 dir = -1;
 575         }
 576
 577         if (_slave->starting()) {
 578                 slave_speed = 0.0f;
 579         }
 580
 581         if (_slave->is_always_synced() ||
 582                         (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 583                         ) {
 584
 585                 /* if the TC source is synced, then we assume that its
 586                    speed is binary: 0.0 or 1.0
 587                 */
 588
 589                 if (slave_speed != 0.0f) {
 590                         slave_speed = 1.0f;
 591                 }
 592
 593         } else {
 594
 595                 /* if we are chasing and the average delta between us and the
 596                    master gets too big, we want to switch to silent
 597                    motion. so keep track of that here.
 598                 */
 599
 600                 if (_slave_state == Running) {
 601                         calculate_moving_average_of_slave_delta(dir, abs(this_delta));
 602                 }
 603         }
 604
 605         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 606
 607         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 608                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 609
 610
 611         if (_slave_state == Running && !_slave->is_always_synced() && !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)) {
 612
 613                 /* may need to varispeed to sync with slave */
 614
 615                 if (_transport_speed != 0.0f) {
 616
 617                         /*
 618                            note that average_dir is +1 or -1
 619                         */
 620
 621                         float delta;
 622
 623                         if (average_slave_delta == 0) {
 624                                 delta = this_delta;
 625                                 delta *= dir;
 626                         } else {
 627                                 delta = average_slave_delta;
 628                                 delta *= average_dir;
 629                         }
 630
 631 #ifndef NDEBUG
 632                         if (slave_speed != 0.0) {
 633                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 634                                                                            (int) (dir * this_delta),
 635                                                                            slave_speed,
 636                                                                            _transport_speed,
 637                                                                            _transport_frame,
 638                                                                            slave_transport_frame,
 639                                                                            average_slave_delta));
 640                         }
 641 #endif
 642
 643                         if (_slave->give_slave_full_control_over_transport_speed()) {
 644                                 set_transport_speed (slave_speed, 0, false, false);
 645                                 //std::cout << "set speed = " << slave_speed << "\n";
 646                         } else {
 647                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 648                                 request_transport_speed (adjusted_speed);
 649                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 650                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 651                                                                            slave_speed));
 652                         }
 653
 654                         if (!actively_recording() && (framecnt_t) average_slave_delta > _slave->resolution()) {
 655                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("average slave delta %1 greater than slave resolution %2 => silent motion\n", average_slave_delta, _slave->resolution()));
 656                                 /* run routes as normal, but no disk output */
 657                                 DiskReader::set_no_disk_output (true);
 658                                 return true;
 659                         }
 660
 661                         if (!have_first_delta_accumulator) {
 662                                 DEBUG_TRACE (DEBUG::Slave, "waiting for first slave delta accumulator to be ready\n");
 663                                 /* run routes as normal, but no disk output */
 664                                 DiskReader::set_no_disk_output (true);
 665                                 return true;
 666                         }
 667                 }
 668         }
 669
 670
 671         if (!have_first_delta_accumulator) {
 672                 DiskReader::set_no_disk_output (true);
 673         } else {
 674                 DiskReader::set_no_disk_output (false);
 675         }
 676
 677         if ((_slave_state == Running) && (0 == (post_transport_work () & ~PostTransportSpeed))) {
 678                 /* speed is set, we're locked, and good to go */
 679                 return true;
 680         }
 681
 682   noroll:
 683         /* don't move at all */
 684         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 685         no_roll (nframes);
 686         return false;
 687 }
 688
 689 void
 690 Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta)
 691 {
 692         if (delta_accumulator_cnt >= delta_accumulator_size) {
 693                 have_first_delta_accumulator = true;
 694                 delta_accumulator_cnt = 0;
 695         }
 696
 697         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 698                 delta_accumulator[delta_accumulator_cnt++] = (framecnt_t) dir *  (framecnt_t) this_delta;
 699         }
 700
 701         if (have_first_delta_accumulator) {
 702                 average_slave_delta = 0L;
 703                 for (int i = 0; i < delta_accumulator_size; ++i) {
 704                         average_slave_delta += delta_accumulator[i];
 705                 }
 706                 average_slave_delta /= (int32_t) delta_accumulator_size;
 707                 if (average_slave_delta < 0L) {
 708                         average_dir = -1;
 709                         average_slave_delta = average_slave_delta;
 710                 } else {
 711                         average_dir = 1;
 712                 }
 713         }
 714 }
 715
 716 void
 717 Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
 718 {
 719         if (slave_speed != 0.0f) {
 720
 721                 /* slave is running */
 722
 723                 switch (_slave_state) {
 724                 case Stopped:
 725                         if (_slave->requires_seekahead()) {
 726                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 727                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 728                                 /* we can call locate() here because we are in process context */
 729                                 locate (slave_wait_end, false, false);
 730                                 _slave_state = Waiting;
 731
 732                         } else {
 733
 734                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_frame));
 735
 736                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 737                                 average_slave_delta = 0L;
 738
 739                                 Location* al = _locations->auto_loop_location();
 740
 741                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 742                                         // cancel looping
 743                                         request_play_loop(false);
 744                                 }
 745
 746                                 if (slave_transport_frame != _transport_frame) {
 747                                         DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_frame, slave_transport_frame));
 748                                         locate (slave_transport_frame, false, false);
 749                                 }
 750                                 _slave_state = Running;
 751                         }
 752                         break;
 753
 754                 case Waiting:
 755                 default:
 756                         break;
 757                 }
 758
 759                 if (_slave_state == Waiting) {
 760
 761                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 762
 763                         if (slave_transport_frame >= slave_wait_end) {
 764
 765                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 766
 767                                 _slave_state = Running;
 768
 769                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 770                                    precisely with the master.
 771                                 */
 772
 773
 774                                 bool ok = true;
 775                                 framecnt_t frame_delta = slave_transport_frame - _transport_frame;
 776
 777                                 boost::shared_ptr<RouteList> rl = routes.reader();
 778                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 779                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 780                                         if (tr && !tr->can_internal_playback_seek (frame_delta)) {
 781                                                 ok = false;
 782                                                 break;
 783                                         }
 784                                 }
 785
 786                                 if (ok) {
 787                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 788                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 789                                                 if (tr) {
 790                                                         tr->internal_playback_seek (frame_delta);
 791                                                 }
 792                                         }
 793                                         _transport_frame += frame_delta;
 794
 795                                 } else {
 796                                         cerr << "cannot micro-seek\n";
 797                                         /* XXX what? */
 798                                 }
 799                         }
 800                 }
 801
 802                 if (_slave_state == Running && _transport_speed == 0.0f) {
 803                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 804                         start_transport ();
 805                 }
 806
 807         } else { // slave_speed is 0
 808
 809                 /* slave has stopped */
 810
 811                 if (_transport_speed != 0.0f) {
 812                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 813                         stop_transport ();
 814                 }
 815
 816                 if (slave_transport_frame != _transport_frame) {
 817                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 818                         force_locate (slave_transport_frame, false);
 819                 }
 820
 821                 reset_slave_state();
 822         }
 823 }
 824
 825 void
 826 Session::process_without_events (pframes_t nframes)
 827 {
 828         bool session_needs_butler = false;
 829         framecnt_t frames_moved;
 830
 831         if (!process_can_proceed()) {
 832                 _silent = true;
 833                 return;
 834         }
 835
 836         if (!_exporting && _slave) {
 837                 if (!follow_slave (nframes)) {
 838                         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame, 0, 0 , nframes);
 839                         return;
 840                 }
 841         }
 842
 843         if (_transport_speed == 0) {
 844                 no_roll (nframes);
 845                 return;
 846         }
 847
 848         if (locate_pending()) {
 849                 frames_moved = 0;
 850         } else {
 851                 if (_transport_speed == 1.0) {
 852                         frames_moved = (framecnt_t) nframes;
 853                 } else {
 854                         interpolation.set_target_speed (_target_transport_speed);
 855                         interpolation.set_speed (_transport_speed);
 856                         frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 857                 }
 858         }
 859
 860         if (!_exporting && !timecode_transmission_suspended()) {
 861                 send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
 862         }
 863
 864         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, _target_transport_speed, _transport_speed, nframes);
 865
 866         framepos_t const stop_limit = compute_stop_limit ();
 867
 868         if (maybe_stop (stop_limit)) {
 869                 no_roll (nframes);
 870                 return;
 871         }
 872
 873         if (maybe_sync_start (nframes)) {
 874                 return;
 875         }
 876
 877         click (_transport_frame, nframes);
 878
 879         if (process_routes (nframes, session_needs_butler)) {
 880                 fail_roll (nframes);
 881                 return;
 882         }
 883
 884         get_track_statistics ();
 885
 886         if (frames_moved < 0) {
 887                 decrement_transport_position (-frames_moved);
 888         } else if (frames_moved) {
 889                 increment_transport_position (frames_moved);
 890         }
 891
 892         maybe_stop (stop_limit);
 893         check_declick_out ();
 894
 895         if (session_needs_butler) {
 896                 DEBUG_TRACE (DEBUG::Butler, "p-without-events: session needs butler, call it\n");
 897                 _butler->summon ();
 898         }
 899 }
 900
 901 /** Process callback used when the auditioner is active.
 902  * @param nframes number of frames to process.
 903  */
 904 void
 905 Session::process_audition (pframes_t nframes)
 906 {
 907         SessionEvent* ev;
 908         boost::shared_ptr<RouteList> r = routes.reader ();
 909
 910         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 911                 if (!(*i)->is_auditioner()) {
 912                         (*i)->silence (nframes);
 913                 }
 914         }
 915
 916         /* run the auditioner, and if it says we need butler service, ask for it */
 917
 918         if (auditioner->play_audition (nframes) > 0) {
 919                 DEBUG_TRACE (DEBUG::Butler, "auditioner needs butler, call it\n");
 920                 _butler->summon ();
 921         }
 922
 923         /* if using a monitor section, run it because otherwise we don't hear anything */
 924
 925         if (_monitor_out && auditioner->needs_monitor()) {
 926                 _monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
 927         }
 928
 929         /* handle pending events */
 930
 931         while (pending_events.read (&ev, 1) == 1) {
 932                 merge_event (ev);
 933         }
 934
 935         /* if we are not in the middle of a state change,
 936            and there are immediate events queued up,
 937            process them.
 938         */
 939
 940         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 941                 SessionEvent *ev = immediate_events.front ();
 942                 immediate_events.pop_front ();
 943                 process_event (ev);
 944         }
 945
 946         if (!auditioner->auditioning()) {
 947                 /* auditioner no longer active, so go back to the normal process callback */
 948                 process_function = &Session::process_with_events;
 949         }
 950 }
 951
 952 bool
 953 Session::maybe_sync_start (pframes_t & nframes)
 954 {
 955         pframes_t sync_offset;
 956
 957         if (!waiting_for_sync_offset) {
 958                 return false;
 959         }
 960
 961         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 962
 963                 /* generate silence up to the sync point, then
 964                    adjust nframes + offset to reflect whatever
 965                    is left to do.
 966                 */
 967
 968                 no_roll (sync_offset);
 969                 nframes -= sync_offset;
 970                 Port::increment_global_port_buffer_offset (sync_offset);
 971                 waiting_for_sync_offset = false;
 972
 973                 if (nframes == 0) {
 974                         return true; // done, nothing left to process
 975                 }
 976
 977         } else {
 978
 979                 /* sync offset point is not within this process()
 980                    cycle, so just generate silence. and don't bother
 981                    with any fancy stuff here, just the minimal silence.
 982                 */
 983
 984                 _silent = true;
 985
 986                 if (Config->get_locate_while_waiting_for_sync()) {
 987                         if (micro_locate (nframes)) {
 988                                 /* XXX ERROR !!! XXX */
 989                         }
 990                 }
 991
 992                 return true; // done, nothing left to process
 993         }
 994
 995         return false;
 996 }
 997
 998 void
 999 Session::queue_event (SessionEvent* ev)
1000 {
1001         if (_state_of_the_state & Deletion) {
1002                 return;
1003         } else if (_state_of_the_state & Loading) {
1004                 merge_event (ev);
1005         } else {
1006                 Glib::Threads::Mutex::Lock lm (rb_write_lock);
1007                 pending_events.write (&ev, 1);
1008         }
1009 }
1010
1011 void
1012 Session::set_next_event ()
1013 {
1014         if (events.empty()) {
1015                 next_event = events.end();
1016                 return;
1017         }
1018
1019         if (next_event == events.end()) {
1020                 next_event = events.begin();
1021         }
1022
1023         if ((*next_event)->action_frame > _transport_frame) {
1024                 next_event = events.begin();
1025         }
1026
1027         for (; next_event != events.end(); ++next_event) {
1028                 if ((*next_event)->action_frame >= _transport_frame) {
1029                         break;
1030                 }
1031         }
1032 }
1033
1034 void
1035 Session::process_event (SessionEvent* ev)
1036 {
1037         bool remove = true;
1038         bool del = true;
1039
1040         /* if we're in the middle of a state change (i.e. waiting
1041            for the butler thread to complete the non-realtime
1042            part of the change), we'll just have to queue this
1043            event for a time when the change is complete.
1044         */
1045
1046         if (non_realtime_work_pending()) {
1047
1048                 /* except locates, which we have the capability to handle */
1049
1050                 if (ev->type != SessionEvent::Locate) {
1051                         immediate_events.insert (immediate_events.end(), ev);
1052                         _remove_event (ev);
1053                         return;
1054                 }
1055         }
1056
1057         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
1058
1059         switch (ev->type) {
1060         case SessionEvent::SetLoop:
1061                 set_play_loop (ev->yes_or_no, ev->speed);
1062                 break;
1063
1064         case SessionEvent::AutoLoop:
1065                 if (play_loop) {
1066                         /* roll after locate, do not flush, set "with loop"
1067                            true only if we are seamless looping
1068                         */
1069                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
1070                 }
1071                 remove = false;
1072                 del = false;
1073                 break;
1074
1075         case SessionEvent::AutoLoopDeclick:
1076                 if (play_loop) {
1077                         /* Request a declick fade-out and a fade-in; the fade-out will happen
1078                            at the end of the loop, and the fade-in at the start.
1079                         */
1080                         transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
1081                 }
1082                 remove = false;
1083                 del = false;
1084                 break;
1085
1086         case SessionEvent::Locate:
1087                 if (ev->yes_or_no) {
1088                         /* args: do not roll after locate, do flush, not with loop */
1089                         locate (ev->target_frame, false, true, false);
1090                 } else {
1091                         /* args: do not roll after locate, do flush, not with loop */
1092                         start_locate (ev->target_frame, false, true, false);
1093                 }
1094                 _send_timecode_update = true;
1095                 break;
1096
1097         case SessionEvent::LocateRoll:
1098                 if (ev->yes_or_no) {
1099                         /* args: roll after locate, do flush, not with loop */
1100                         locate (ev->target_frame, true, true, false);
1101                 } else {
1102                         /* args: roll after locate, do flush, not with loop */
1103                         start_locate (ev->target_frame, true, true, false);
1104                 }
1105                 _send_timecode_update = true;
1106                 break;
1107
1108         case SessionEvent::Skip:
1109                 if (Config->get_skip_playback()) {
1110                         start_locate (ev->target_frame, true, true, false);
1111                         _send_timecode_update = true;
1112                 }
1113                 remove = false;
1114                 del = false;
1115                 break;
1116
1117         case SessionEvent::LocateRollLocate:
1118                 // locate is handled by ::request_roll_at_and_return()
1119                 _requested_return_frame = ev->target_frame;
1120                 request_locate (ev->target2_frame, true);
1121                 break;
1122
1123
1124         case SessionEvent::SetTransportSpeed:
1125                 set_transport_speed (ev->speed, ev->target_frame, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
1126                 break;
1127
1128         case SessionEvent::PunchIn:
1129                 // cerr << "PunchIN at " << transport_frame() << endl;
1130                 if (config.get_punch_in() && record_status() == Enabled && !preroll_record_punch_enabled()) {
1131                         enable_record ();
1132                 }
1133                 remove = false;
1134                 del = false;
1135                 break;
1136
1137         case SessionEvent::PunchOut:
1138                 // cerr << "PunchOUT at " << transport_frame() << endl;
1139                 if (config.get_punch_out() && !preroll_record_punch_enabled()) {
1140                         step_back_from_record ();
1141                 }
1142                 remove = false;
1143                 del = false;
1144                 break;
1145
1146         case SessionEvent::RecordStart:
1147                 if (preroll_record_punch_enabled() && record_status() == Enabled) {
1148                         enable_record ();
1149                 }
1150                 remove = false;
1151                 del = false;
1152                 break;
1153
1154         case SessionEvent::StopOnce:
1155                 if (!non_realtime_work_pending()) {
1156                         _clear_event_type (SessionEvent::StopOnce);
1157                         stop_transport (ev->yes_or_no);
1158                 }
1159                 remove = false;
1160                 del = false;
1161                 break;
1162
1163         case SessionEvent::RangeStop:
1164                 if (!non_realtime_work_pending()) {
1165                         stop_transport (ev->yes_or_no);
1166                 }
1167                 remove = false;
1168                 del = false;
1169                 break;
1170
1171         case SessionEvent::RangeLocate:
1172                 /* args: roll after locate, do flush, not with loop */
1173                 start_locate (ev->target_frame, true, true, false);
1174                 remove = false;
1175                 del = false;
1176                 break;
1177
1178         case SessionEvent::Overwrite:
1179                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1180                 break;
1181
1182         case SessionEvent::SetSyncSource:
1183                 DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
1184                 use_sync_source (ev->slave);
1185                 break;
1186
1187         case SessionEvent::Audition:
1188                 set_audition (ev->region);
1189                 // drop reference to region
1190                 ev->region.reset ();
1191                 break;
1192
1193         case SessionEvent::SetPlayAudioRange:
1194                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1195                 break;
1196
1197         case SessionEvent::CancelPlayAudioRange:
1198                 unset_play_range();
1199                 break;
1200
1201         case SessionEvent::RealTimeOperation:
1202                 process_rtop (ev);
1203                 del = false; // other side of RT request needs to clean up
1204                 break;
1205
1206         case SessionEvent::AdjustPlaybackBuffering:
1207                 schedule_playback_buffering_adjustment ();
1208                 break;
1209
1210         case SessionEvent::AdjustCaptureBuffering:
1211                 schedule_capture_buffering_adjustment ();
1212                 break;
1213
1214         case SessionEvent::SetTimecodeTransmission:
1215                 g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
1216                 break;
1217
1218         default:
1219           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1220                 abort(); /*NOTREACHED*/
1221                 break;
1222         };
1223
1224         if (remove) {
1225                 del = del && !_remove_event (ev);
1226         }
1227
1228         if (del) {
1229                 delete ev;
1230         }
1231 }
1232
1233 framepos_t
1234 Session::compute_stop_limit () const
1235 {
1236         if (!Config->get_stop_at_session_end ()) {
1237                 return max_framepos;
1238         }
1239
1240         if (_slave) {
1241                 return max_framepos;
1242         }
1243
1244         if (preroll_record_punch_enabled ()) {
1245                 return max_framepos;
1246         }
1247
1248         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1249         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1250
1251         if (actively_recording ()) {
1252                 /* permanently recording */
1253                 return max_framepos;
1254         } else if (punching_in && !punching_out) {
1255                 /* punching in but never out */
1256                 return max_framepos;
1257         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
1258                 /* punching in and punching out after session end */
1259                 return max_framepos;
1260         }
1261
1262         return current_end_frame ();
1263 }
1264
1265
1266
1267 /* dedicated thread for signal emission.
1268  *
1269  * while sending cross-thread signals from the process thread
1270  * is fine in general, PBD::Signal's use of boost::function and
1271  * boost:bind can produce a vast overhead which is not
1272  * acceptable for low latency.
1273  *
1274  * This works around the issue by moving the boost overhead
1275  * out of the RT thread. The overall load is probably higher but
1276  * the realtime thread remains unaffected.
1277  */
1278
1279 void
1280 Session::emit_route_signals ()
1281 {
1282         // TODO use RAII to allow using these signals in other places
1283         BatchUpdateStart(); /* EMIT SIGNAL */
1284         boost::shared_ptr<RouteList> r = routes.reader ();
1285         for (RouteList::const_iterator ci = r->begin(); ci != r->end(); ++ci) {
1286                 (*ci)->emit_pending_signals ();
1287         }
1288         BatchUpdateEnd(); /* EMIT SIGNAL */
1289 }
1290
1291 void
1292 Session::emit_thread_start ()
1293 {
1294         if (_rt_thread_active) {
1295                 return;
1296         }
1297         _rt_thread_active = true;
1298
1299         if (pthread_create (&_rt_emit_thread, NULL, emit_thread, this)) {
1300                 _rt_thread_active = false;
1301         }
1302 }
1303
1304 void
1305 Session::emit_thread_terminate ()
1306 {
1307         if (!_rt_thread_active) {
1308                 return;
1309         }
1310         _rt_thread_active = false;
1311
1312         if (pthread_mutex_lock (&_rt_emit_mutex) == 0) {
1313                 pthread_cond_signal (&_rt_emit_cond);
1314                 pthread_mutex_unlock (&_rt_emit_mutex);
1315         }
1316
1317         void *status;
1318         pthread_join (_rt_emit_thread, &status);
1319 }
1320
1321 void *
1322 Session::emit_thread (void *arg)
1323 {
1324         Session *s = static_cast<Session *>(arg);
1325         s->emit_thread_run ();
1326         pthread_exit (0);
1327         return 0;
1328 }
1329
1330 void
1331 Session::emit_thread_run ()
1332 {
1333         pthread_mutex_lock (&_rt_emit_mutex);
1334         while (_rt_thread_active) {
1335                 emit_route_signals();
1336                 pthread_cond_wait (&_rt_emit_cond, &_rt_emit_mutex);
1337         }
1338         pthread_mutex_unlock (&_rt_emit_mutex);
1339 }