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 /** @param need_butler to be set to true by this method if it needs the butler,
 234  *  otherwise it must be left alone.
 235  */
 236 int
 237 Session::silent_process_routes (pframes_t nframes, bool& need_butler)
 238 {
 239         DiskReader::set_no_disk_output (true);
 240         int ret = process_routes (nframes, need_butler);
 241         DiskReader::set_no_disk_output (false);
 242         return ret;
 243 }
 244
 245 void
 246 Session::get_track_statistics ()
 247 {
 248         float pworst = 1.0f;
 249         float cworst = 1.0f;
 250
 251         boost::shared_ptr<RouteList> rl = routes.reader();
 252         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 253
 254                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 255
 256                 if (!tr || tr->is_private_route()) {
 257                         continue;
 258                 }
 259
 260                 pworst = min (pworst, tr->playback_buffer_load());
 261                 cworst = min (cworst, tr->capture_buffer_load());
 262         }
 263
 264         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 265         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 266
 267         if (actively_recording()) {
 268                 set_dirty();
 269         }
 270 }
 271
 272 /** Process callback used when the auditioner is not active */
 273 void
 274 Session::process_with_events (pframes_t nframes)
 275 {
 276         PT_TIMING_CHECK (3);
 277
 278         SessionEvent*  ev;
 279         pframes_t      this_nframes;
 280         framepos_t     end_frame;
 281         bool           session_needs_butler = false;
 282         framecnt_t     frames_moved;
 283
 284         /* make sure the auditioner is silent */
 285
 286         if (auditioner) {
 287                 auditioner->silence (nframes);
 288         }
 289
 290         /* handle any pending events */
 291
 292         while (pending_events.read (&ev, 1) == 1) {
 293                 merge_event (ev);
 294         }
 295
 296         /* if we are not in the middle of a state change,
 297            and there are immediate events queued up,
 298            process them.
 299         */
 300
 301         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 302                 SessionEvent *ev = immediate_events.front ();
 303                 immediate_events.pop_front ();
 304                 process_event (ev);
 305         }
 306
 307         /* count in */
 308         if (_transport_speed != 1.0 && _count_in_samples > 0) {
 309                 _count_in_samples = 0;
 310         }
 311
 312         if (_count_in_samples > 0) {
 313                 framecnt_t ns = std::min ((framecnt_t)nframes, _count_in_samples);
 314
 315                 no_roll (ns);
 316                 run_click (_transport_frame - _count_in_samples, ns);
 317
 318                 _count_in_samples -= ns;
 319                 nframes -= ns;
 320
 321                 /* process events.. */
 322                 if (!events.empty() && next_event != events.end()) {
 323                         SessionEvent* this_event = *next_event;
 324                         Events::iterator the_next_one = next_event;
 325                         ++the_next_one;
 326
 327                         while (this_event && this_event->action_frame == _transport_frame) {
 328                                 process_event (this_event);
 329                                 if (the_next_one == events.end()) {
 330                                         this_event = 0;
 331                                 } else {
 332                                         this_event = *the_next_one;
 333                                         ++the_next_one;
 334                                 }
 335                         }
 336                         set_next_event ();
 337                 }
 338
 339                 check_declick_out ();
 340
 341                 if (nframes == 0) {
 342                         return;
 343                 } else {
 344                         _engine.split_cycle (ns);
 345                 }
 346         }
 347
 348         /* Decide on what to do with quarter-frame MTC during this cycle */
 349
 350         bool const was_sending_qf_mtc = _send_qf_mtc;
 351         double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
 352
 353         if (_transport_speed != 0) {
 354                 _send_qf_mtc = (
 355                         Config->get_send_mtc () &&
 356                         _transport_speed >= (1 - tolerance) &&
 357                         _transport_speed <= (1 + tolerance)
 358                         );
 359
 360                 if (_send_qf_mtc && !was_sending_qf_mtc) {
 361                         /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
 362                         _send_timecode_update = true;
 363                 }
 364
 365                 if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
 366                         /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
 367                            a quarter of a second since we sent anything at all, so send a full MTC update
 368                            this cycle.
 369                         */
 370                         _send_timecode_update = true;
 371                 }
 372
 373                 _pframes_since_last_mtc += nframes;
 374         }
 375
 376         /* Events caused a transport change (or we re-started sending
 377          * MTC), so send an MTC Full Frame (Timecode) message.  This
 378          * is sent whether rolling or not, to give slaves an idea of
 379          * ardour time on locates (and allow slow slaves to position
 380          * and prepare for rolling)
 381          */
 382         if (_send_timecode_update) {
 383                 send_full_time_code (_transport_frame, nframes);
 384         }
 385
 386         if (!process_can_proceed()) {
 387                 _silent = true;
 388                 return;
 389         }
 390
 391         if (events.empty() || next_event == events.end()) {
 392                 try_run_lua (nframes); // also during export ?? ->move to process_without_events()
 393                 /* lua scripts may inject events */
 394                 while (_n_lua_scripts > 0 && pending_events.read (&ev, 1) == 1) {
 395                         merge_event (ev);
 396                 }
 397                 if (events.empty() || next_event == events.end()) {
 398                         process_without_events (nframes);
 399                         return;
 400                 }
 401         }
 402
 403         if (locate_pending()) {
 404                 frames_moved = 0;
 405         } else {
 406                 if (_transport_speed == 1.0) {
 407                         frames_moved = (framecnt_t) nframes;
 408                 } else {
 409                         interpolation.set_target_speed (_target_transport_speed);
 410                         interpolation.set_speed (_transport_speed);
 411                         frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 412                 }
 413         }
 414
 415         end_frame = _transport_frame + frames_moved;
 416
 417         {
 418                 SessionEvent* this_event;
 419                 Events::iterator the_next_one;
 420
 421                 if (!process_can_proceed()) {
 422                         _silent = true;
 423                         return;
 424                 }
 425
 426                 if (!_exporting && _slave) {
 427                         if (!follow_slave (nframes)) {
 428                                 return;
 429                         }
 430                 }
 431
 432                 if (_transport_speed == 0) {
 433                         no_roll (nframes);
 434                         return;
 435                 }
 436
 437                 if (!_exporting && !timecode_transmission_suspended()) {
 438                         send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
 439                 }
 440
 441                 ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 442
 443                 framepos_t stop_limit = compute_stop_limit ();
 444
 445                 if (maybe_stop (stop_limit)) {
 446                         no_roll (nframes);
 447                         return;
 448                 }
 449
 450                 this_event = *next_event;
 451                 the_next_one = next_event;
 452                 ++the_next_one;
 453
 454                 /* yes folks, here it is, the actual loop where we really truly
 455                    process some audio
 456                 */
 457
 458                 while (nframes) {
 459
 460                         this_nframes = nframes; /* real (jack) time relative */
 461                         if (locate_pending()) {
 462                                 frames_moved = 0;
 463                         } else {
 464                                 frames_moved = (framecnt_t) floor (_transport_speed * nframes); /* transport relative */
 465                         }
 466
 467                         /* running an event, position transport precisely to its time */
 468                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 469                                 /* this isn't quite right for reverse play */
 470                                 frames_moved = (framecnt_t) (this_event->action_frame - _transport_frame);
 471                                 this_nframes = abs (floor(frames_moved / _transport_speed));
 472                         }
 473
 474                         try_run_lua (this_nframes);
 475
 476                         if (this_nframes) {
 477
 478                                 click (_transport_frame, this_nframes);
 479
 480                                 if (process_routes (this_nframes, session_needs_butler)) {
 481                                         fail_roll (nframes);
 482                                         return;
 483                                 }
 484
 485                                 get_track_statistics ();
 486
 487                                 nframes -= this_nframes;
 488
 489                                 if (frames_moved < 0) {
 490                                         decrement_transport_position (-frames_moved);
 491                                 } else if (frames_moved) {
 492                                         increment_transport_position (frames_moved);
 493                                 }
 494
 495                                 maybe_stop (stop_limit);
 496                                 check_declick_out ();
 497                         }
 498
 499                         if (nframes > 0) {
 500                                 _engine.split_cycle (this_nframes);
 501                         }
 502
 503                         /* now handle this event and all others scheduled for the same time */
 504
 505                         while (this_event && this_event->action_frame == _transport_frame) {
 506                                 process_event (this_event);
 507
 508                                 if (the_next_one == events.end()) {
 509                                         this_event = 0;
 510                                 } else {
 511                                         this_event = *the_next_one;
 512                                         ++the_next_one;
 513                                 }
 514                         }
 515
 516                         /* if an event left our state changing, do the right thing */
 517
 518                         if (nframes && non_realtime_work_pending()) {
 519                                 no_roll (nframes);
 520                                 break;
 521                         }
 522
 523                         /* this is necessary to handle the case of seamless looping */
 524                         end_frame = _transport_frame + floor (nframes * _transport_speed);
 525                 }
 526
 527                 set_next_event ();
 528
 529         } /* implicit release of route lock */
 530
 531         if (session_needs_butler) {
 532                 DEBUG_TRACE (DEBUG::Butler, "p-with-events: session needs butler, call it\n");
 533                 _butler->summon ();
 534         }
 535 }
 536
 537 void
 538 Session::reset_slave_state ()
 539 {
 540         average_slave_delta = 1800;
 541         delta_accumulator_cnt = 0;
 542         have_first_delta_accumulator = false;
 543         _slave_state = Stopped;
 544 }
 545
 546 bool
 547 Session::transport_locked () const
 548 {
 549         Slave* sl = _slave;
 550
 551         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 552                 return true;
 553         }
 554
 555         return false;
 556 }
 557
 558 bool
 559 Session::follow_slave (pframes_t nframes)
 560 {
 561         double slave_speed;
 562         framepos_t slave_transport_frame;
 563         framecnt_t this_delta;
 564         int dir;
 565
 566         if (!_slave->ok()) {
 567                 stop_transport ();
 568                 config.set_external_sync (false);
 569                 goto noroll;
 570         }
 571
 572         _slave->speed_and_position (slave_speed, slave_transport_frame);
 573
 574         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 575
 576         if (!_slave->locked()) {
 577                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 578                 goto noroll;
 579         }
 580
 581         if (slave_transport_frame > _transport_frame) {
 582                 this_delta = slave_transport_frame - _transport_frame;
 583                 dir = 1;
 584         } else {
 585                 this_delta = _transport_frame - slave_transport_frame;
 586                 dir = -1;
 587         }
 588
 589         if (_slave->starting()) {
 590                 slave_speed = 0.0f;
 591         }
 592
 593         if (_slave->is_always_synced() ||
 594                         (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 595                         ) {
 596
 597                 /* if the TC source is synced, then we assume that its
 598                    speed is binary: 0.0 or 1.0
 599                 */
 600
 601                 if (slave_speed != 0.0f) {
 602                         slave_speed = 1.0f;
 603                 }
 604
 605         } else {
 606
 607                 /* if we are chasing and the average delta between us and the
 608                    master gets too big, we want to switch to silent
 609                    motion. so keep track of that here.
 610                 */
 611
 612                 if (_slave_state == Running) {
 613                         calculate_moving_average_of_slave_delta(dir, this_delta);
 614                 }
 615         }
 616
 617         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 618
 619         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 620                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 621
 622
 623         if (_slave_state == Running && !_slave->is_always_synced() &&
 624                         !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 625                         ) {
 626
 627                 if (_transport_speed != 0.0f) {
 628
 629                         /*
 630                            note that average_dir is +1 or -1
 631                         */
 632
 633                         float delta;
 634
 635                         if (average_slave_delta == 0) {
 636                                 delta = this_delta;
 637                                 delta *= dir;
 638                         } else {
 639                                 delta = average_slave_delta;
 640                                 delta *= average_dir;
 641                         }
 642
 643 #ifndef NDEBUG
 644                         if (slave_speed != 0.0) {
 645                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 646                                                                            (int) (dir * this_delta),
 647                                                                            slave_speed,
 648                                                                            _transport_speed,
 649                                                                            _transport_frame,
 650                                                                            slave_transport_frame,
 651                                                                            average_slave_delta));
 652                         }
 653 #endif
 654
 655                         if (_slave->give_slave_full_control_over_transport_speed()) {
 656                                 set_transport_speed (slave_speed, 0, false, false);
 657                                 //std::cout << "set speed = " << slave_speed << "\n";
 658                         } else {
 659                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 660                                 request_transport_speed (adjusted_speed);
 661                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 662                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 663                                                                            slave_speed));
 664                         }
 665
 666 #if 1
 667                         if (!actively_recording() && (framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
 668                                 cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
 669                                 goto silent_motion;
 670                         }
 671 #endif
 672                 }
 673         }
 674
 675
 676         if (_slave_state == Running && 0 == (post_transport_work () & ~PostTransportSpeed)) {
 677                 /* speed is set, we're locked, and good to go */
 678                 return true;
 679         }
 680
 681   silent_motion:
 682         DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
 683         follow_slave_silently (nframes, slave_speed);
 684
 685   noroll:
 686         /* don't move at all */
 687         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 688         no_roll (nframes);
 689         return false;
 690 }
 691
 692 void
 693 Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta)
 694 {
 695         if (delta_accumulator_cnt >= delta_accumulator_size) {
 696                 have_first_delta_accumulator = true;
 697                 delta_accumulator_cnt = 0;
 698         }
 699
 700         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 701                 delta_accumulator[delta_accumulator_cnt++] = (framecnt_t) dir *  (framecnt_t) this_delta;
 702         }
 703
 704         if (have_first_delta_accumulator) {
 705                 average_slave_delta = 0L;
 706                 for (int i = 0; i < delta_accumulator_size; ++i) {
 707                         average_slave_delta += delta_accumulator[i];
 708                 }
 709                 average_slave_delta /= (int32_t) delta_accumulator_size;
 710                 if (average_slave_delta < 0L) {
 711                         average_dir = -1;
 712                         average_slave_delta = abs(average_slave_delta);
 713                 } else {
 714                         average_dir = 1;
 715                 }
 716         }
 717 }
 718
 719 void
 720 Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
 721 {
 722         if (slave_speed != 0.0f) {
 723
 724                 /* slave is running */
 725
 726                 switch (_slave_state) {
 727                 case Stopped:
 728                         if (_slave->requires_seekahead()) {
 729                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 730                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 731                                 /* we can call locate() here because we are in process context */
 732                                 locate (slave_wait_end, false, false);
 733                                 _slave_state = Waiting;
 734
 735                         } else {
 736
 737                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_frame));
 738
 739                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 740                                 average_slave_delta = 0L;
 741
 742                                 Location* al = _locations->auto_loop_location();
 743
 744                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 745                                         // cancel looping
 746                                         request_play_loop(false);
 747                                 }
 748
 749                                 if (slave_transport_frame != _transport_frame) {
 750                                         DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_frame, slave_transport_frame));
 751                                         locate (slave_transport_frame, false, false);
 752                                 }
 753                                 _slave_state = Running;
 754                         }
 755                         break;
 756
 757                 case Waiting:
 758                 default:
 759                         break;
 760                 }
 761
 762                 if (_slave_state == Waiting) {
 763
 764                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 765
 766                         if (slave_transport_frame >= slave_wait_end) {
 767
 768                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 769
 770                                 _slave_state = Running;
 771
 772                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 773                                    precisely with the master.
 774                                 */
 775
 776
 777                                 bool ok = true;
 778                                 framecnt_t frame_delta = slave_transport_frame - _transport_frame;
 779
 780                                 boost::shared_ptr<RouteList> rl = routes.reader();
 781                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 782                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 783                                         if (tr && !tr->can_internal_playback_seek (frame_delta)) {
 784                                                 ok = false;
 785                                                 break;
 786                                         }
 787                                 }
 788
 789                                 if (ok) {
 790                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 791                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 792                                                 if (tr) {
 793                                                         tr->internal_playback_seek (frame_delta);
 794                                                 }
 795                                         }
 796                                         _transport_frame += frame_delta;
 797
 798                                 } else {
 799                                         cerr << "cannot micro-seek\n";
 800                                         /* XXX what? */
 801                                 }
 802                         }
 803                 }
 804
 805                 if (_slave_state == Running && _transport_speed == 0.0f) {
 806                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 807                         start_transport ();
 808                 }
 809
 810         } else { // slave_speed is 0
 811
 812                 /* slave has stopped */
 813
 814                 if (_transport_speed != 0.0f) {
 815                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 816                         stop_transport ();
 817                 }
 818
 819                 if (slave_transport_frame != _transport_frame) {
 820                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 821                         force_locate (slave_transport_frame, false);
 822                 }
 823
 824                 reset_slave_state();
 825         }
 826 }
 827
 828 void
 829 Session::follow_slave_silently (pframes_t nframes, float slave_speed)
 830 {
 831         if (slave_speed && _transport_speed) {
 832
 833                 /* something isn't right, but we should move with the master
 834                    for now.
 835                 */
 836
 837                 bool need_butler = false;
 838
 839                 silent_process_routes (nframes, need_butler);
 840
 841                 get_track_statistics ();
 842
 843                 if (need_butler) {
 844                         DEBUG_TRACE (DEBUG::Butler, "f-slave-silently: session needs butler, call it\n");
 845                         _butler->summon ();
 846                 }
 847
 848                 int32_t frames_moved;
 849
 850                 if (locate_pending()) {
 851                         frames_moved = 0;
 852                 } else {
 853                         frames_moved = (int32_t) floor (_transport_speed * nframes);
 854                 }
 855
 856                 if (frames_moved < 0) {
 857                         decrement_transport_position (-frames_moved);
 858                 } else if (frames_moved) {
 859                         increment_transport_position (frames_moved);
 860                 }
 861
 862                 framepos_t const stop_limit = compute_stop_limit ();
 863                 maybe_stop (stop_limit);
 864         }
 865 }
 866
 867 void
 868 Session::process_without_events (pframes_t nframes)
 869 {
 870         bool session_needs_butler = false;
 871         framecnt_t frames_moved;
 872
 873         if (!process_can_proceed()) {
 874                 _silent = true;
 875                 return;
 876         }
 877
 878         if (!_exporting && _slave) {
 879                 if (!follow_slave (nframes)) {
 880                         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame, 0, 0 , nframes);
 881                         return;
 882                 }
 883         }
 884
 885         if (_transport_speed == 0) {
 886                 no_roll (nframes);
 887                 return;
 888         }
 889
 890         if (locate_pending()) {
 891                 frames_moved = 0;
 892         } else {
 893                 if (_transport_speed == 1.0) {
 894                         frames_moved = (framecnt_t) nframes;
 895                 } else {
 896                         interpolation.set_target_speed (_target_transport_speed);
 897                         interpolation.set_speed (_transport_speed);
 898                         frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 899                 }
 900         }
 901
 902         if (!_exporting && !timecode_transmission_suspended()) {
 903                 send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
 904         }
 905
 906         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, _target_transport_speed, _transport_speed, nframes);
 907
 908         framepos_t const stop_limit = compute_stop_limit ();
 909
 910         if (maybe_stop (stop_limit)) {
 911                 no_roll (nframes);
 912                 return;
 913         }
 914
 915         if (maybe_sync_start (nframes)) {
 916                 return;
 917         }
 918
 919         click (_transport_frame, nframes);
 920
 921         if (process_routes (nframes, session_needs_butler)) {
 922                 fail_roll (nframes);
 923                 return;
 924         }
 925
 926         get_track_statistics ();
 927
 928         if (frames_moved < 0) {
 929                 decrement_transport_position (-frames_moved);
 930         } else if (frames_moved) {
 931                 increment_transport_position (frames_moved);
 932         }
 933
 934         maybe_stop (stop_limit);
 935         check_declick_out ();
 936
 937         if (session_needs_butler) {
 938                 DEBUG_TRACE (DEBUG::Butler, "p-without-events: session needs butler, call it\n");
 939                 _butler->summon ();
 940         }
 941 }
 942
 943 /** Process callback used when the auditioner is active.
 944  * @param nframes number of frames to process.
 945  */
 946 void
 947 Session::process_audition (pframes_t nframes)
 948 {
 949         SessionEvent* ev;
 950         boost::shared_ptr<RouteList> r = routes.reader ();
 951
 952         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 953                 if (!(*i)->is_auditioner()) {
 954                         (*i)->silence (nframes);
 955                 }
 956         }
 957
 958         /* run the auditioner, and if it says we need butler service, ask for it */
 959
 960         if (auditioner->play_audition (nframes) > 0) {
 961                 DEBUG_TRACE (DEBUG::Butler, "auditioner needs butler, call it\n");
 962                 _butler->summon ();
 963         }
 964
 965         /* if using a monitor section, run it because otherwise we don't hear anything */
 966
 967         if (_monitor_out && auditioner->needs_monitor()) {
 968                 _monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
 969         }
 970
 971         /* handle pending events */
 972
 973         while (pending_events.read (&ev, 1) == 1) {
 974                 merge_event (ev);
 975         }
 976
 977         /* if we are not in the middle of a state change,
 978            and there are immediate events queued up,
 979            process them.
 980         */
 981
 982         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 983                 SessionEvent *ev = immediate_events.front ();
 984                 immediate_events.pop_front ();
 985                 process_event (ev);
 986         }
 987
 988         if (!auditioner->auditioning()) {
 989                 /* auditioner no longer active, so go back to the normal process callback */
 990                 process_function = &Session::process_with_events;
 991         }
 992 }
 993
 994 bool
 995 Session::maybe_sync_start (pframes_t & nframes)
 996 {
 997         pframes_t sync_offset;
 998
 999         if (!waiting_for_sync_offset) {
1000                 return false;
1001         }
1002
1003         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
1004
1005                 /* generate silence up to the sync point, then
1006                    adjust nframes + offset to reflect whatever
1007                    is left to do.
1008                 */
1009
1010                 no_roll (sync_offset);
1011                 nframes -= sync_offset;
1012                 Port::increment_global_port_buffer_offset (sync_offset);
1013                 waiting_for_sync_offset = false;
1014
1015                 if (nframes == 0) {
1016                         return true; // done, nothing left to process
1017                 }
1018
1019         } else {
1020
1021                 /* sync offset point is not within this process()
1022                    cycle, so just generate silence. and don't bother
1023                    with any fancy stuff here, just the minimal silence.
1024                 */
1025
1026                 _silent = true;
1027
1028                 if (Config->get_locate_while_waiting_for_sync()) {
1029                         if (micro_locate (nframes)) {
1030                                 /* XXX ERROR !!! XXX */
1031                         }
1032                 }
1033
1034                 return true; // done, nothing left to process
1035         }
1036
1037         return false;
1038 }
1039
1040 void
1041 Session::queue_event (SessionEvent* ev)
1042 {
1043         if (_state_of_the_state & Deletion) {
1044                 return;
1045         } else if (_state_of_the_state & Loading) {
1046                 merge_event (ev);
1047         } else {
1048                 Glib::Threads::Mutex::Lock lm (rb_write_lock);
1049                 pending_events.write (&ev, 1);
1050         }
1051 }
1052
1053 void
1054 Session::set_next_event ()
1055 {
1056         if (events.empty()) {
1057                 next_event = events.end();
1058                 return;
1059         }
1060
1061         if (next_event == events.end()) {
1062                 next_event = events.begin();
1063         }
1064
1065         if ((*next_event)->action_frame > _transport_frame) {
1066                 next_event = events.begin();
1067         }
1068
1069         for (; next_event != events.end(); ++next_event) {
1070                 if ((*next_event)->action_frame >= _transport_frame) {
1071                         break;
1072                 }
1073         }
1074 }
1075
1076 void
1077 Session::process_event (SessionEvent* ev)
1078 {
1079         bool remove = true;
1080         bool del = true;
1081
1082         /* if we're in the middle of a state change (i.e. waiting
1083            for the butler thread to complete the non-realtime
1084            part of the change), we'll just have to queue this
1085            event for a time when the change is complete.
1086         */
1087
1088         if (non_realtime_work_pending()) {
1089
1090                 /* except locates, which we have the capability to handle */
1091
1092                 if (ev->type != SessionEvent::Locate) {
1093                         immediate_events.insert (immediate_events.end(), ev);
1094                         _remove_event (ev);
1095                         return;
1096                 }
1097         }
1098
1099         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
1100
1101         switch (ev->type) {
1102         case SessionEvent::SetLoop:
1103                 set_play_loop (ev->yes_or_no, ev->speed);
1104                 break;
1105
1106         case SessionEvent::AutoLoop:
1107                 if (play_loop) {
1108                         /* roll after locate, do not flush, set "with loop"
1109                            true only if we are seamless looping
1110                         */
1111                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
1112                 }
1113                 remove = false;
1114                 del = false;
1115                 break;
1116
1117         case SessionEvent::AutoLoopDeclick:
1118                 if (play_loop) {
1119                         /* Request a declick fade-out and a fade-in; the fade-out will happen
1120                            at the end of the loop, and the fade-in at the start.
1121                         */
1122                         transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
1123                 }
1124                 remove = false;
1125                 del = false;
1126                 break;
1127
1128         case SessionEvent::Locate:
1129                 if (ev->yes_or_no) {
1130                         /* args: do not roll after locate, do flush, not with loop */
1131                         locate (ev->target_frame, false, true, false);
1132                 } else {
1133                         /* args: do not roll after locate, do flush, not with loop */
1134                         start_locate (ev->target_frame, false, true, false);
1135                 }
1136                 _send_timecode_update = true;
1137                 break;
1138
1139         case SessionEvent::LocateRoll:
1140                 if (ev->yes_or_no) {
1141                         /* args: roll after locate, do flush, not with loop */
1142                         locate (ev->target_frame, true, true, false);
1143                 } else {
1144                         /* args: roll after locate, do flush, not with loop */
1145                         start_locate (ev->target_frame, true, true, false);
1146                 }
1147                 _send_timecode_update = true;
1148                 break;
1149
1150         case SessionEvent::Skip:
1151                 if (Config->get_skip_playback()) {
1152                         start_locate (ev->target_frame, true, true, false);
1153                         _send_timecode_update = true;
1154                 }
1155                 remove = false;
1156                 del = false;
1157                 break;
1158
1159         case SessionEvent::LocateRollLocate:
1160                 // locate is handled by ::request_roll_at_and_return()
1161                 _requested_return_frame = ev->target_frame;
1162                 request_locate (ev->target2_frame, true);
1163                 break;
1164
1165
1166         case SessionEvent::SetTransportSpeed:
1167                 set_transport_speed (ev->speed, ev->target_frame, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
1168                 break;
1169
1170         case SessionEvent::PunchIn:
1171                 // cerr << "PunchIN at " << transport_frame() << endl;
1172                 if (config.get_punch_in() && record_status() == Enabled && !preroll_record_punch_enabled()) {
1173                         enable_record ();
1174                 }
1175                 remove = false;
1176                 del = false;
1177                 break;
1178
1179         case SessionEvent::PunchOut:
1180                 // cerr << "PunchOUT at " << transport_frame() << endl;
1181                 if (config.get_punch_out() && !preroll_record_punch_enabled()) {
1182                         step_back_from_record ();
1183                 }
1184                 remove = false;
1185                 del = false;
1186                 break;
1187
1188         case SessionEvent::RecordStart:
1189                 if (preroll_record_punch_enabled() && record_status() == Enabled) {
1190                         enable_record ();
1191                 }
1192                 remove = false;
1193                 del = false;
1194                 break;
1195
1196         case SessionEvent::StopOnce:
1197                 if (!non_realtime_work_pending()) {
1198                         _clear_event_type (SessionEvent::StopOnce);
1199                         stop_transport (ev->yes_or_no);
1200                 }
1201                 remove = false;
1202                 del = false;
1203                 break;
1204
1205         case SessionEvent::RangeStop:
1206                 if (!non_realtime_work_pending()) {
1207                         stop_transport (ev->yes_or_no);
1208                 }
1209                 remove = false;
1210                 del = false;
1211                 break;
1212
1213         case SessionEvent::RangeLocate:
1214                 /* args: roll after locate, do flush, not with loop */
1215                 start_locate (ev->target_frame, true, true, false);
1216                 remove = false;
1217                 del = false;
1218                 break;
1219
1220         case SessionEvent::Overwrite:
1221                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1222                 break;
1223
1224         case SessionEvent::SetSyncSource:
1225                 DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
1226                 use_sync_source (ev->slave);
1227                 break;
1228
1229         case SessionEvent::Audition:
1230                 set_audition (ev->region);
1231                 // drop reference to region
1232                 ev->region.reset ();
1233                 break;
1234
1235         case SessionEvent::SetPlayAudioRange:
1236                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1237                 break;
1238
1239         case SessionEvent::CancelPlayAudioRange:
1240                 unset_play_range();
1241                 break;
1242
1243         case SessionEvent::RealTimeOperation:
1244                 process_rtop (ev);
1245                 del = false; // other side of RT request needs to clean up
1246                 break;
1247
1248         case SessionEvent::AdjustPlaybackBuffering:
1249                 schedule_playback_buffering_adjustment ();
1250                 break;
1251
1252         case SessionEvent::AdjustCaptureBuffering:
1253                 schedule_capture_buffering_adjustment ();
1254                 break;
1255
1256         case SessionEvent::SetTimecodeTransmission:
1257                 g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
1258                 break;
1259
1260         default:
1261           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1262                 abort(); /*NOTREACHED*/
1263                 break;
1264         };
1265
1266         if (remove) {
1267                 del = del && !_remove_event (ev);
1268         }
1269
1270         if (del) {
1271                 delete ev;
1272         }
1273 }
1274
1275 framepos_t
1276 Session::compute_stop_limit () const
1277 {
1278         if (!Config->get_stop_at_session_end ()) {
1279                 return max_framepos;
1280         }
1281
1282         if (_slave) {
1283                 return max_framepos;
1284         }
1285
1286         if (preroll_record_punch_enabled ()) {
1287                 return max_framepos;
1288         }
1289
1290         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1291         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1292
1293         if (actively_recording ()) {
1294                 /* permanently recording */
1295                 return max_framepos;
1296         } else if (punching_in && !punching_out) {
1297                 /* punching in but never out */
1298                 return max_framepos;
1299         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
1300                 /* punching in and punching out after session end */
1301                 return max_framepos;
1302         }
1303
1304         return current_end_frame ();
1305 }
1306
1307
1308
1309 /* dedicated thread for signal emission.
1310  *
1311  * while sending cross-thread signals from the process thread
1312  * is fine in general, PBD::Signal's use of boost::function and
1313  * boost:bind can produce a vast overhead which is not
1314  * acceptable for low latency.
1315  *
1316  * This works around the issue by moving the boost overhead
1317  * out of the RT thread. The overall load is probably higher but
1318  * the realtime thread remains unaffected.
1319  */
1320
1321 void
1322 Session::emit_route_signals ()
1323 {
1324         // TODO use RAII to allow using these signals in other places
1325         BatchUpdateStart(); /* EMIT SIGNAL */
1326         boost::shared_ptr<RouteList> r = routes.reader ();
1327         for (RouteList::const_iterator ci = r->begin(); ci != r->end(); ++ci) {
1328                 (*ci)->emit_pending_signals ();
1329         }
1330         BatchUpdateEnd(); /* EMIT SIGNAL */
1331 }
1332
1333 void
1334 Session::emit_thread_start ()
1335 {
1336         if (_rt_thread_active) {
1337                 return;
1338         }
1339         _rt_thread_active = true;
1340
1341         if (pthread_create (&_rt_emit_thread, NULL, emit_thread, this)) {
1342                 _rt_thread_active = false;
1343         }
1344 }
1345
1346 void
1347 Session::emit_thread_terminate ()
1348 {
1349         if (!_rt_thread_active) {
1350                 return;
1351         }
1352         _rt_thread_active = false;
1353
1354         if (pthread_mutex_lock (&_rt_emit_mutex) == 0) {
1355                 pthread_cond_signal (&_rt_emit_cond);
1356                 pthread_mutex_unlock (&_rt_emit_mutex);
1357         }
1358
1359         void *status;
1360         pthread_join (_rt_emit_thread, &status);
1361 }
1362
1363 void *
1364 Session::emit_thread (void *arg)
1365 {
1366         Session *s = static_cast<Session *>(arg);
1367         s->emit_thread_run ();
1368         pthread_exit (0);
1369         return 0;
1370 }
1371
1372 void
1373 Session::emit_thread_run ()
1374 {
1375         pthread_mutex_lock (&_rt_emit_mutex);
1376         while (_rt_thread_active) {
1377                 emit_route_signals();
1378                 pthread_cond_wait (&_rt_emit_cond, &_rt_emit_mutex);
1379         }
1380         pthread_mutex_unlock (&_rt_emit_mutex);
1381 }