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/graph.h"
  36 #include "ardour/port.h"
  37 #include "ardour/process_thread.h"
  38 #include "ardour/scene_changer.h"
  39 #include "ardour/session.h"
  40 #include "ardour/slave.h"
  41 #include "ardour/ticker.h"
  42 #include "ardour/types.h"
  43 #include "ardour/vca.h"
  44 #include "ardour/vca_manager.h"
  45
  46 #include "midi++/mmc.h"
  47
  48 #include "pbd/i18n.h"
  49
  50 using namespace ARDOUR;
  51 using namespace PBD;
  52 using namespace std;
  53
  54 /** Called by the audio engine when there is work to be done with JACK.
  55  * @param nframes Number of frames to process.
  56  */
  57
  58 void
  59 Session::process (pframes_t nframes)
  60 {
  61         framepos_t transport_at_start = _transport_frame;
  62
  63         _silent = false;
  64
  65         if (processing_blocked()) {
  66                 _silent = true;
  67                 return;
  68         }
  69
  70         if (non_realtime_work_pending()) {
  71                 if (!_butler->transport_work_requested ()) {
  72                         post_transport ();
  73                 }
  74         }
  75
  76         _engine.main_thread()->get_buffers ();
  77
  78         (this->*process_function) (nframes);
  79
  80         /* realtime-safe meter-position and processor-order changes
  81          *
  82          * ideally this would be done in
  83          * Route::process_output_buffers() but various functions
  84          * callig it hold a _processor_lock reader-lock
  85          */
  86         boost::shared_ptr<RouteList> r = routes.reader ();
  87         for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
  88                 if ((*i)->apply_processor_changes_rt()) {
  89                         _rt_emit_pending = true;
  90                 }
  91         }
  92         if (_rt_emit_pending) {
  93                 if (!_rt_thread_active) {
  94                         emit_route_signals ();
  95                 }
  96                 if (pthread_mutex_trylock (&_rt_emit_mutex) == 0) {
  97                         pthread_cond_signal (&_rt_emit_cond);
  98                         pthread_mutex_unlock (&_rt_emit_mutex);
  99                         _rt_emit_pending = false;
 100                 }
 101         }
 102
 103         _engine.main_thread()->drop_buffers ();
 104
 105         /* deliver MIDI clock. Note that we need to use the transport frame
 106          * position at the start of process(), not the value at the end of
 107          * it. We may already have ticked() because of a transport state
 108          * change, for example.
 109          */
 110
 111         try {
 112                 if (!_silent && !_engine.freewheeling() && Config->get_send_midi_clock() && (transport_speed() == 1.0f || transport_speed() == 0.0f) && midi_clock->has_midi_port()) {
 113                         midi_clock->tick (transport_at_start, nframes);
 114                 }
 115
 116                 _scene_changer->run (transport_at_start, transport_at_start + nframes);
 117
 118         } catch (...) {
 119                 /* don't bother with a message */
 120         }
 121
 122         SendFeedback (); /* EMIT SIGNAL */
 123 }
 124
 125 int
 126 Session::fail_roll (pframes_t nframes)
 127 {
 128         return no_roll (nframes);
 129 }
 130
 131 int
 132 Session::no_roll (pframes_t nframes)
 133 {
 134         PT_TIMING_CHECK (4);
 135
 136         framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
 137         int ret = 0;
 138         int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
 139         boost::shared_ptr<RouteList> r = routes.reader ();
 140
 141         if (_click_io) {
 142                 _click_io->silence (nframes);
 143         }
 144
 145         ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 146
 147         VCAList v = _vca_manager->vcas ();
 148         for (VCAList::const_iterator i = v.begin(); i != v.end(); ++i) {
 149                 (*i)->automation_run (_transport_frame, nframes);
 150         }
 151
 152         if (_process_graph) {
 153                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
 154                 _process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
 155         } else {
 156                 PT_TIMING_CHECK (10);
 157                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 158
 159                         if ((*i)->is_auditioner()) {
 160                                 continue;
 161                         }
 162
 163                         (*i)->set_pending_declick (declick);
 164
 165                         if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending())) {
 166                                 error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 167                                 ret = -1;
 168                                 break;
 169                         }
 170                 }
 171                 PT_TIMING_CHECK (11);
 172         }
 173
 174         PT_TIMING_CHECK (5);
 175         return ret;
 176 }
 177
 178 /** @param need_butler to be set to true by this method if it needs the butler,
 179  *  otherwise it must be left alone.
 180  */
 181 int
 182 Session::process_routes (pframes_t nframes, bool& need_butler)
 183 {
 184         int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
 185         boost::shared_ptr<RouteList> r = routes.reader ();
 186
 187         const framepos_t start_frame = _transport_frame;
 188         const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
 189
 190         VCAList v = _vca_manager->vcas ();
 191         for (VCAList::const_iterator i = v.begin(); i != v.end(); ++i) {
 192                 (*i)->automation_run (start_frame, nframes);
 193         }
 194
 195         if (_process_graph) {
 196                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
 197                 if (_process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler) < 0) {
 198                         stop_transport ();
 199                         return -1;
 200                 }
 201         } else {
 202
 203                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 204
 205                         int ret;
 206
 207                         if ((*i)->is_auditioner()) {
 208                                 continue;
 209                         }
 210
 211                         (*i)->set_pending_declick (declick);
 212
 213                         bool b = false;
 214
 215                         if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, b)) < 0) {
 216                                 stop_transport ();
 217                                 return -1;
 218                         }
 219
 220                         if (b) {
 221                                 DEBUG_TRACE (DEBUG::Butler, string_compose ("%1 rolled and needs butler\n", (*i)->name()));
 222                                 need_butler = true;
 223                         }
 224                 }
 225         }
 226
 227         return 0;
 228 }
 229
 230 /** @param need_butler to be set to true by this method if it needs the butler,
 231  *  otherwise it must be left alone.
 232  */
 233 int
 234 Session::silent_process_routes (pframes_t nframes, bool& need_butler)
 235 {
 236         boost::shared_ptr<RouteList> r = routes.reader ();
 237
 238         const framepos_t start_frame = _transport_frame;
 239         const framepos_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 240
 241         VCAList v = _vca_manager->vcas ();
 242         for (VCAList::const_iterator i = v.begin(); i != v.end(); ++i) {
 243                 (*i)->automation_run (start_frame, nframes);
 244         }
 245
 246         if (_process_graph) {
 247                 _process_graph->silent_process_routes (nframes, start_frame, end_frame, need_butler);
 248         } else {
 249                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 250
 251                         int ret;
 252
 253                         if ((*i)->is_auditioner()) {
 254                                 continue;
 255                         }
 256
 257                         bool b = false;
 258
 259                         if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, b)) < 0) {
 260                                 stop_transport ();
 261                                 return -1;
 262                         }
 263
 264                         if (b) {
 265                                 need_butler = true;
 266                         }
 267                 }
 268         }
 269
 270         return 0;
 271 }
 272
 273 void
 274 Session::get_track_statistics ()
 275 {
 276         float pworst = 1.0f;
 277         float cworst = 1.0f;
 278
 279         boost::shared_ptr<RouteList> rl = routes.reader();
 280         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 281
 282                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 283
 284                 if (!tr || tr->hidden()) {
 285                         continue;
 286                 }
 287
 288                 pworst = min (pworst, tr->playback_buffer_load());
 289                 cworst = min (cworst, tr->capture_buffer_load());
 290         }
 291
 292         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 293         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 294
 295         if (actively_recording()) {
 296                 set_dirty();
 297         }
 298 }
 299
 300 /** Process callback used when the auditioner is not active */
 301 void
 302 Session::process_with_events (pframes_t nframes)
 303 {
 304         PT_TIMING_CHECK (3);
 305
 306         SessionEvent*  ev;
 307         pframes_t      this_nframes;
 308         framepos_t     end_frame;
 309         bool           session_needs_butler = false;
 310         framecnt_t     frames_moved;
 311
 312         /* make sure the auditioner is silent */
 313
 314         if (auditioner) {
 315                 auditioner->silence (nframes);
 316         }
 317
 318         /* handle any pending events */
 319
 320         while (pending_events.read (&ev, 1) == 1) {
 321                 merge_event (ev);
 322         }
 323
 324         /* if we are not in the middle of a state change,
 325            and there are immediate events queued up,
 326            process them.
 327         */
 328
 329         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 330                 SessionEvent *ev = immediate_events.front ();
 331                 immediate_events.pop_front ();
 332                 process_event (ev);
 333         }
 334
 335         /* count in */
 336         if (_transport_speed != 1.0 && _count_in_samples > 0) {
 337                 _count_in_samples = 0;
 338         }
 339
 340         if (_count_in_samples > 0) {
 341                 framecnt_t ns = std::min ((framecnt_t)nframes, _count_in_samples);
 342
 343                 no_roll (ns);
 344                 run_click (_transport_frame - _count_in_samples, ns);
 345
 346                 _count_in_samples -= ns;
 347                 nframes -= ns;
 348
 349                 /* process events.. */
 350                 if (!events.empty() && next_event != events.end()) {
 351                         SessionEvent* this_event = *next_event;
 352                         Events::iterator the_next_one = next_event;
 353                         ++the_next_one;
 354
 355                         while (this_event && this_event->action_frame == _transport_frame) {
 356                                 process_event (this_event);
 357                                 if (the_next_one == events.end()) {
 358                                         this_event = 0;
 359                                 } else {
 360                                         this_event = *the_next_one;
 361                                         ++the_next_one;
 362                                 }
 363                         }
 364                         set_next_event ();
 365                 }
 366
 367                 check_declick_out ();
 368
 369                 if (nframes == 0) {
 370                         return;
 371                 } else {
 372                         _engine.split_cycle (ns);
 373                 }
 374         }
 375
 376         /* Decide on what to do with quarter-frame MTC during this cycle */
 377
 378         bool const was_sending_qf_mtc = _send_qf_mtc;
 379         double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
 380
 381         if (_transport_speed != 0) {
 382                 _send_qf_mtc = (
 383                         Config->get_send_mtc () &&
 384                         _transport_speed >= (1 - tolerance) &&
 385                         _transport_speed <= (1 + tolerance)
 386                         );
 387
 388                 if (_send_qf_mtc && !was_sending_qf_mtc) {
 389                         /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
 390                         _send_timecode_update = true;
 391                 }
 392
 393                 if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
 394                         /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
 395                            a quarter of a second since we sent anything at all, so send a full MTC update
 396                            this cycle.
 397                         */
 398                         _send_timecode_update = true;
 399                 }
 400
 401                 _pframes_since_last_mtc += nframes;
 402         }
 403
 404         /* Events caused a transport change (or we re-started sending
 405          * MTC), so send an MTC Full Frame (Timecode) message.  This
 406          * is sent whether rolling or not, to give slaves an idea of
 407          * ardour time on locates (and allow slow slaves to position
 408          * and prepare for rolling)
 409          */
 410         if (_send_timecode_update) {
 411                 send_full_time_code (_transport_frame, nframes);
 412         }
 413
 414         if (!process_can_proceed()) {
 415                 _silent = true;
 416                 return;
 417         }
 418
 419         if (events.empty() || next_event == events.end()) {
 420                 try_run_lua (nframes); // also during export ?? ->move to process_without_events()
 421                 /* lua scripts may inject events */
 422                 while (_n_lua_scripts > 0 && pending_events.read (&ev, 1) == 1) {
 423                         merge_event (ev);
 424                 }
 425                 if (events.empty() || next_event == events.end()) {
 426                         process_without_events (nframes);
 427                         return;
 428                 }
 429         }
 430
 431         if (_transport_speed == 1.0) {
 432                 frames_moved = (framecnt_t) nframes;
 433         } else {
 434                 interpolation.set_target_speed (_target_transport_speed);
 435                 interpolation.set_speed (_transport_speed);
 436                 frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 437         }
 438
 439         end_frame = _transport_frame + frames_moved;
 440
 441         {
 442                 SessionEvent* this_event;
 443                 Events::iterator the_next_one;
 444
 445                 if (!process_can_proceed()) {
 446                         _silent = true;
 447                         return;
 448                 }
 449
 450                 if (!_exporting && _slave) {
 451                         if (!follow_slave (nframes)) {
 452                                 return;
 453                         }
 454                 }
 455
 456                 if (_transport_speed == 0) {
 457                         no_roll (nframes);
 458                         return;
 459                 }
 460
 461                 if (!_exporting && !timecode_transmission_suspended()) {
 462                         send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
 463                 }
 464
 465                 ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 466
 467                 framepos_t stop_limit = compute_stop_limit ();
 468
 469                 if (maybe_stop (stop_limit)) {
 470                         no_roll (nframes);
 471                         return;
 472                 }
 473
 474                 this_event = *next_event;
 475                 the_next_one = next_event;
 476                 ++the_next_one;
 477
 478                 /* yes folks, here it is, the actual loop where we really truly
 479                    process some audio
 480                 */
 481
 482                 while (nframes) {
 483
 484                         this_nframes = nframes; /* real (jack) time relative */
 485                         frames_moved = (framecnt_t) floor (_transport_speed * nframes); /* transport relative */
 486
 487                         /* running an event, position transport precisely to its time */
 488                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 489                                 /* this isn't quite right for reverse play */
 490                                 frames_moved = (framecnt_t) (this_event->action_frame - _transport_frame);
 491                                 this_nframes = abs (floor(frames_moved / _transport_speed));
 492                         }
 493
 494                         try_run_lua (this_nframes);
 495
 496                         if (this_nframes) {
 497
 498                                 click (_transport_frame, this_nframes);
 499
 500                                 if (process_routes (this_nframes, session_needs_butler)) {
 501                                         fail_roll (nframes);
 502                                         return;
 503                                 }
 504
 505                                 get_track_statistics ();
 506
 507                                 nframes -= this_nframes;
 508
 509                                 if (frames_moved < 0) {
 510                                         decrement_transport_position (-frames_moved);
 511                                 } else {
 512                                         increment_transport_position (frames_moved);
 513                                 }
 514
 515                                 maybe_stop (stop_limit);
 516                                 check_declick_out ();
 517                         }
 518
 519                         if (nframes > 0) {
 520                                 _engine.split_cycle (this_nframes);
 521                         }
 522
 523                         /* now handle this event and all others scheduled for the same time */
 524
 525                         while (this_event && this_event->action_frame == _transport_frame) {
 526                                 process_event (this_event);
 527
 528                                 if (the_next_one == events.end()) {
 529                                         this_event = 0;
 530                                 } else {
 531                                         this_event = *the_next_one;
 532                                         ++the_next_one;
 533                                 }
 534                         }
 535
 536                         /* if an event left our state changing, do the right thing */
 537
 538                         if (nframes && non_realtime_work_pending()) {
 539                                 no_roll (nframes);
 540                                 break;
 541                         }
 542
 543                         /* this is necessary to handle the case of seamless looping */
 544                         end_frame = _transport_frame + floor (nframes * _transport_speed);
 545                 }
 546
 547                 set_next_event ();
 548
 549         } /* implicit release of route lock */
 550
 551         if (session_needs_butler) {
 552                 DEBUG_TRACE (DEBUG::Butler, "p-with-events: session needs butler, call it\n");
 553                 _butler->summon ();
 554         }
 555 }
 556
 557 void
 558 Session::reset_slave_state ()
 559 {
 560         average_slave_delta = 1800;
 561         delta_accumulator_cnt = 0;
 562         have_first_delta_accumulator = false;
 563         _slave_state = Stopped;
 564 }
 565
 566 bool
 567 Session::transport_locked () const
 568 {
 569         Slave* sl = _slave;
 570
 571         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 572                 return true;
 573         }
 574
 575         return false;
 576 }
 577
 578 bool
 579 Session::follow_slave (pframes_t nframes)
 580 {
 581         double slave_speed;
 582         framepos_t slave_transport_frame;
 583         framecnt_t this_delta;
 584         int dir;
 585
 586         if (!_slave->ok()) {
 587                 stop_transport ();
 588                 config.set_external_sync (false);
 589                 goto noroll;
 590         }
 591
 592         _slave->speed_and_position (slave_speed, slave_transport_frame);
 593
 594         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 595
 596         if (!_slave->locked()) {
 597                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 598                 goto noroll;
 599         }
 600
 601         if (slave_transport_frame > _transport_frame) {
 602                 this_delta = slave_transport_frame - _transport_frame;
 603                 dir = 1;
 604         } else {
 605                 this_delta = _transport_frame - slave_transport_frame;
 606                 dir = -1;
 607         }
 608
 609         if (_slave->starting()) {
 610                 slave_speed = 0.0f;
 611         }
 612
 613         if (_slave->is_always_synced() ||
 614                         (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 615                         ) {
 616
 617                 /* if the TC source is synced, then we assume that its
 618                    speed is binary: 0.0 or 1.0
 619                 */
 620
 621                 if (slave_speed != 0.0f) {
 622                         slave_speed = 1.0f;
 623                 }
 624
 625         } else {
 626
 627                 /* if we are chasing and the average delta between us and the
 628                    master gets too big, we want to switch to silent
 629                    motion. so keep track of that here.
 630                 */
 631
 632                 if (_slave_state == Running) {
 633                         calculate_moving_average_of_slave_delta(dir, this_delta);
 634                 }
 635         }
 636
 637         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 638
 639         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 640                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 641
 642
 643         if (_slave_state == Running && !_slave->is_always_synced() &&
 644                         !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 645                         ) {
 646
 647                 if (_transport_speed != 0.0f) {
 648
 649                         /*
 650                            note that average_dir is +1 or -1
 651                         */
 652
 653                         float delta;
 654
 655                         if (average_slave_delta == 0) {
 656                                 delta = this_delta;
 657                                 delta *= dir;
 658                         } else {
 659                                 delta = average_slave_delta;
 660                                 delta *= average_dir;
 661                         }
 662
 663 #ifndef NDEBUG
 664                         if (slave_speed != 0.0) {
 665                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 666                                                                            (int) (dir * this_delta),
 667                                                                            slave_speed,
 668                                                                            _transport_speed,
 669                                                                            _transport_frame,
 670                                                                            slave_transport_frame,
 671                                                                            average_slave_delta));
 672                         }
 673 #endif
 674
 675                         if (_slave->give_slave_full_control_over_transport_speed()) {
 676                                 set_transport_speed (slave_speed, 0, false, false);
 677                                 //std::cout << "set speed = " << slave_speed << "\n";
 678                         } else {
 679                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 680                                 request_transport_speed (adjusted_speed);
 681                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 682                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 683                                                                            slave_speed));
 684                         }
 685
 686 #if 1
 687                         if (!actively_recording() && (framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
 688                                 cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
 689                                 goto silent_motion;
 690                         }
 691 #endif
 692                 }
 693         }
 694
 695
 696         if (_slave_state == Running && 0 == (post_transport_work () & ~PostTransportSpeed)) {
 697                 /* speed is set, we're locked, and good to go */
 698                 return true;
 699         }
 700
 701   silent_motion:
 702         DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
 703         follow_slave_silently (nframes, slave_speed);
 704
 705   noroll:
 706         /* don't move at all */
 707         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 708         no_roll (nframes);
 709         return false;
 710 }
 711
 712 void
 713 Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta)
 714 {
 715         if (delta_accumulator_cnt >= delta_accumulator_size) {
 716                 have_first_delta_accumulator = true;
 717                 delta_accumulator_cnt = 0;
 718         }
 719
 720         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 721                 delta_accumulator[delta_accumulator_cnt++] = (framecnt_t) dir *  (framecnt_t) this_delta;
 722         }
 723
 724         if (have_first_delta_accumulator) {
 725                 average_slave_delta = 0L;
 726                 for (int i = 0; i < delta_accumulator_size; ++i) {
 727                         average_slave_delta += delta_accumulator[i];
 728                 }
 729                 average_slave_delta /= (int32_t) delta_accumulator_size;
 730                 if (average_slave_delta < 0L) {
 731                         average_dir = -1;
 732                         average_slave_delta = abs(average_slave_delta);
 733                 } else {
 734                         average_dir = 1;
 735                 }
 736         }
 737 }
 738
 739 void
 740 Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
 741 {
 742         if (slave_speed != 0.0f) {
 743
 744                 /* slave is running */
 745
 746                 switch (_slave_state) {
 747                 case Stopped:
 748                         if (_slave->requires_seekahead()) {
 749                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 750                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 751                                 /* we can call locate() here because we are in process context */
 752                                 locate (slave_wait_end, false, false);
 753                                 _slave_state = Waiting;
 754
 755                         } else {
 756
 757                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_frame));
 758
 759                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 760                                 average_slave_delta = 0L;
 761
 762                                 Location* al = _locations->auto_loop_location();
 763
 764                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 765                                         // cancel looping
 766                                         request_play_loop(false);
 767                                 }
 768
 769                                 if (slave_transport_frame != _transport_frame) {
 770                                         DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_frame, slave_transport_frame));
 771                                         locate (slave_transport_frame, false, false);
 772                                 }
 773                                 _slave_state = Running;
 774                         }
 775                         break;
 776
 777                 case Waiting:
 778                 default:
 779                         break;
 780                 }
 781
 782                 if (_slave_state == Waiting) {
 783
 784                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 785
 786                         if (slave_transport_frame >= slave_wait_end) {
 787
 788                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 789
 790                                 _slave_state = Running;
 791
 792                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 793                                    precisely with the master.
 794                                 */
 795
 796
 797                                 bool ok = true;
 798                                 framecnt_t frame_delta = slave_transport_frame - _transport_frame;
 799
 800                                 boost::shared_ptr<RouteList> rl = routes.reader();
 801                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 802                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 803                                         if (tr && !tr->can_internal_playback_seek (frame_delta)) {
 804                                                 ok = false;
 805                                                 break;
 806                                         }
 807                                 }
 808
 809                                 if (ok) {
 810                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 811                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 812                                                 if (tr) {
 813                                                         tr->internal_playback_seek (frame_delta);
 814                                                 }
 815                                         }
 816                                         _transport_frame += frame_delta;
 817
 818                                 } else {
 819                                         cerr << "cannot micro-seek\n";
 820                                         /* XXX what? */
 821                                 }
 822                         }
 823                 }
 824
 825                 if (_slave_state == Running && _transport_speed == 0.0f) {
 826                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 827                         start_transport ();
 828                 }
 829
 830         } else { // slave_speed is 0
 831
 832                 /* slave has stopped */
 833
 834                 if (_transport_speed != 0.0f) {
 835                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 836                         stop_transport ();
 837                 }
 838
 839                 if (slave_transport_frame != _transport_frame) {
 840                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 841                         force_locate (slave_transport_frame, false);
 842                 }
 843
 844                 reset_slave_state();
 845         }
 846 }
 847
 848 void
 849 Session::follow_slave_silently (pframes_t nframes, float slave_speed)
 850 {
 851         if (slave_speed && _transport_speed) {
 852
 853                 /* something isn't right, but we should move with the master
 854                    for now.
 855                 */
 856
 857                 bool need_butler = false;
 858
 859                 silent_process_routes (nframes, need_butler);
 860
 861                 get_track_statistics ();
 862
 863                 if (need_butler) {
 864                         DEBUG_TRACE (DEBUG::Butler, "f-slave-silently: session needs butler, call it\n");
 865                         _butler->summon ();
 866                 }
 867
 868                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 869
 870                 if (frames_moved < 0) {
 871                         decrement_transport_position (-frames_moved);
 872                 } else {
 873                         increment_transport_position (frames_moved);
 874                 }
 875
 876                 framepos_t const stop_limit = compute_stop_limit ();
 877                 maybe_stop (stop_limit);
 878         }
 879 }
 880
 881 void
 882 Session::process_without_events (pframes_t nframes)
 883 {
 884         bool session_needs_butler = false;
 885         framecnt_t frames_moved;
 886
 887         if (!process_can_proceed()) {
 888                 _silent = true;
 889                 return;
 890         }
 891
 892         if (!_exporting && _slave) {
 893                 if (!follow_slave (nframes)) {
 894                         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame, 0, 0 , nframes);
 895                         return;
 896                 }
 897         }
 898
 899         if (_transport_speed == 0) {
 900                 fail_roll (nframes);
 901                 return;
 902         }
 903
 904         if (_transport_speed == 1.0) {
 905                 frames_moved = (framecnt_t) nframes;
 906         } else {
 907                 interpolation.set_target_speed (_target_transport_speed);
 908                 interpolation.set_speed (_transport_speed);
 909                 frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 910         }
 911
 912         if (!_exporting && !timecode_transmission_suspended()) {
 913                 send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
 914         }
 915
 916         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, _target_transport_speed, _transport_speed, nframes);
 917
 918         framepos_t const stop_limit = compute_stop_limit ();
 919
 920         if (maybe_stop (stop_limit)) {
 921                 fail_roll (nframes);
 922                 return;
 923         }
 924
 925         if (maybe_sync_start (nframes)) {
 926                 return;
 927         }
 928
 929         click (_transport_frame, nframes);
 930
 931         if (process_routes (nframes, session_needs_butler)) {
 932                 fail_roll (nframes);
 933                 return;
 934         }
 935
 936         get_track_statistics ();
 937
 938         if (frames_moved < 0) {
 939                 decrement_transport_position (-frames_moved);
 940         } else {
 941                 increment_transport_position (frames_moved);
 942         }
 943
 944         maybe_stop (stop_limit);
 945         check_declick_out ();
 946
 947         if (session_needs_butler) {
 948                 DEBUG_TRACE (DEBUG::Butler, "p-without-events: session needs butler, call it\n");
 949                 _butler->summon ();
 950         }
 951 }
 952
 953 /** Process callback used when the auditioner is active.
 954  * @param nframes number of frames to process.
 955  */
 956 void
 957 Session::process_audition (pframes_t nframes)
 958 {
 959         SessionEvent* ev;
 960         boost::shared_ptr<RouteList> r = routes.reader ();
 961
 962         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 963                 if (!(*i)->is_auditioner()) {
 964                         (*i)->silence (nframes);
 965                 }
 966         }
 967
 968         /* run the auditioner, and if it says we need butler service, ask for it */
 969
 970         if (auditioner->play_audition (nframes) > 0) {
 971                 DEBUG_TRACE (DEBUG::Butler, "auditioner needs butler, call it\n");
 972                 _butler->summon ();
 973         }
 974
 975         /* if using a monitor section, run it because otherwise we don't hear anything */
 976
 977         if (_monitor_out && auditioner->needs_monitor()) {
 978                 _monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
 979         }
 980
 981         /* handle pending events */
 982
 983         while (pending_events.read (&ev, 1) == 1) {
 984                 merge_event (ev);
 985         }
 986
 987         /* if we are not in the middle of a state change,
 988            and there are immediate events queued up,
 989            process them.
 990         */
 991
 992         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 993                 SessionEvent *ev = immediate_events.front ();
 994                 immediate_events.pop_front ();
 995                 process_event (ev);
 996         }
 997
 998         if (!auditioner->auditioning()) {
 999                 /* auditioner no longer active, so go back to the normal process callback */
1000                 process_function = &Session::process_with_events;
1001         }
1002 }
1003
1004 bool
1005 Session::maybe_sync_start (pframes_t & nframes)
1006 {
1007         pframes_t sync_offset;
1008
1009         if (!waiting_for_sync_offset) {
1010                 return false;
1011         }
1012
1013         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
1014
1015                 /* generate silence up to the sync point, then
1016                    adjust nframes + offset to reflect whatever
1017                    is left to do.
1018                 */
1019
1020                 no_roll (sync_offset);
1021                 nframes -= sync_offset;
1022                 Port::increment_global_port_buffer_offset (sync_offset);
1023                 waiting_for_sync_offset = false;
1024
1025                 if (nframes == 0) {
1026                         return true; // done, nothing left to process
1027                 }
1028
1029         } else {
1030
1031                 /* sync offset point is not within this process()
1032                    cycle, so just generate silence. and don't bother
1033                    with any fancy stuff here, just the minimal silence.
1034                 */
1035
1036                 _silent = true;
1037
1038                 if (Config->get_locate_while_waiting_for_sync()) {
1039                         if (micro_locate (nframes)) {
1040                                 /* XXX ERROR !!! XXX */
1041                         }
1042                 }
1043
1044                 return true; // done, nothing left to process
1045         }
1046
1047         return false;
1048 }
1049
1050 void
1051 Session::queue_event (SessionEvent* ev)
1052 {
1053         if (_state_of_the_state & Deletion) {
1054                 return;
1055         } else if (_state_of_the_state & Loading) {
1056                 merge_event (ev);
1057         } else {
1058                 Glib::Threads::Mutex::Lock lm (rb_write_lock);
1059                 pending_events.write (&ev, 1);
1060         }
1061 }
1062
1063 void
1064 Session::set_next_event ()
1065 {
1066         if (events.empty()) {
1067                 next_event = events.end();
1068                 return;
1069         }
1070
1071         if (next_event == events.end()) {
1072                 next_event = events.begin();
1073         }
1074
1075         if ((*next_event)->action_frame > _transport_frame) {
1076                 next_event = events.begin();
1077         }
1078
1079         for (; next_event != events.end(); ++next_event) {
1080                 if ((*next_event)->action_frame >= _transport_frame) {
1081                         break;
1082                 }
1083         }
1084 }
1085
1086 void
1087 Session::process_event (SessionEvent* ev)
1088 {
1089         bool remove = true;
1090         bool del = true;
1091
1092         /* if we're in the middle of a state change (i.e. waiting
1093            for the butler thread to complete the non-realtime
1094            part of the change), we'll just have to queue this
1095            event for a time when the change is complete.
1096         */
1097
1098         if (non_realtime_work_pending()) {
1099
1100                 /* except locates, which we have the capability to handle */
1101
1102                 if (ev->type != SessionEvent::Locate) {
1103                         immediate_events.insert (immediate_events.end(), ev);
1104                         _remove_event (ev);
1105                         return;
1106                 }
1107         }
1108
1109         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
1110
1111         switch (ev->type) {
1112         case SessionEvent::SetLoop:
1113                 set_play_loop (ev->yes_or_no, ev->speed);
1114                 break;
1115
1116         case SessionEvent::AutoLoop:
1117                 if (play_loop) {
1118                         /* roll after locate, do not flush, set "with loop"
1119                            true only if we are seamless looping
1120                         */
1121                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
1122                 }
1123                 remove = false;
1124                 del = false;
1125                 break;
1126
1127         case SessionEvent::AutoLoopDeclick:
1128                 if (play_loop) {
1129                         /* Request a declick fade-out and a fade-in; the fade-out will happen
1130                            at the end of the loop, and the fade-in at the start.
1131                         */
1132                         transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
1133                 }
1134                 remove = false;
1135                 del = false;
1136                 break;
1137
1138         case SessionEvent::Locate:
1139                 if (ev->yes_or_no) {
1140                         /* args: do not roll after locate, do flush, not with loop */
1141                         locate (ev->target_frame, false, true, false);
1142                 } else {
1143                         /* args: do not roll after locate, do flush, not with loop */
1144                         start_locate (ev->target_frame, false, true, false);
1145                 }
1146                 _send_timecode_update = true;
1147                 break;
1148
1149         case SessionEvent::LocateRoll:
1150                 if (ev->yes_or_no) {
1151                         /* args: roll after locate, do flush, not with loop */
1152                         locate (ev->target_frame, true, true, false);
1153                 } else {
1154                         /* args: roll after locate, do flush, not with loop */
1155                         start_locate (ev->target_frame, true, true, false);
1156                 }
1157                 _send_timecode_update = true;
1158                 break;
1159
1160         case SessionEvent::Skip:
1161                 if (Config->get_skip_playback()) {
1162                         start_locate (ev->target_frame, true, true, false);
1163                         _send_timecode_update = true;
1164                 }
1165                 remove = false;
1166                 del = false;
1167                 break;
1168
1169         case SessionEvent::LocateRollLocate:
1170                 // locate is handled by ::request_roll_at_and_return()
1171                 _requested_return_frame = ev->target_frame;
1172                 request_locate (ev->target2_frame, true);
1173                 break;
1174
1175
1176         case SessionEvent::SetTransportSpeed:
1177                 set_transport_speed (ev->speed, ev->target_frame, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
1178                 break;
1179
1180         case SessionEvent::PunchIn:
1181                 // cerr << "PunchIN at " << transport_frame() << endl;
1182                 if (config.get_punch_in() && record_status() == Enabled && !preroll_record_punch_enabled()) {
1183                         enable_record ();
1184                 }
1185                 remove = false;
1186                 del = false;
1187                 break;
1188
1189         case SessionEvent::PunchOut:
1190                 // cerr << "PunchOUT at " << transport_frame() << endl;
1191                 if (config.get_punch_out() && !preroll_record_punch_enabled()) {
1192                         step_back_from_record ();
1193                 }
1194                 remove = false;
1195                 del = false;
1196                 break;
1197
1198         case SessionEvent::RecordStart:
1199                 if (preroll_record_punch_enabled() && record_status() == Enabled) {
1200                         enable_record ();
1201                 }
1202                 remove = false;
1203                 del = false;
1204                 break;
1205
1206         case SessionEvent::StopOnce:
1207                 if (!non_realtime_work_pending()) {
1208                         _clear_event_type (SessionEvent::StopOnce);
1209                         stop_transport (ev->yes_or_no);
1210                 }
1211                 remove = false;
1212                 del = false;
1213                 break;
1214
1215         case SessionEvent::RangeStop:
1216                 if (!non_realtime_work_pending()) {
1217                         stop_transport (ev->yes_or_no);
1218                 }
1219                 remove = false;
1220                 del = false;
1221                 break;
1222
1223         case SessionEvent::RangeLocate:
1224                 /* args: roll after locate, do flush, not with loop */
1225                 start_locate (ev->target_frame, true, true, false);
1226                 remove = false;
1227                 del = false;
1228                 break;
1229
1230         case SessionEvent::Overwrite:
1231                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1232                 break;
1233
1234         case SessionEvent::SetSyncSource:
1235                 DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
1236                 use_sync_source (ev->slave);
1237                 break;
1238
1239         case SessionEvent::Audition:
1240                 set_audition (ev->region);
1241                 // drop reference to region
1242                 ev->region.reset ();
1243                 break;
1244
1245         case SessionEvent::SetPlayAudioRange:
1246                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1247                 break;
1248
1249         case SessionEvent::CancelPlayAudioRange:
1250                 unset_play_range();
1251                 break;
1252
1253         case SessionEvent::RealTimeOperation:
1254                 process_rtop (ev);
1255                 del = false; // other side of RT request needs to clean up
1256                 break;
1257
1258         case SessionEvent::AdjustPlaybackBuffering:
1259                 schedule_playback_buffering_adjustment ();
1260                 break;
1261
1262         case SessionEvent::AdjustCaptureBuffering:
1263                 schedule_capture_buffering_adjustment ();
1264                 break;
1265
1266         case SessionEvent::SetTimecodeTransmission:
1267                 g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
1268                 break;
1269
1270         default:
1271           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1272                 abort(); /*NOTREACHED*/
1273                 break;
1274         };
1275
1276         if (remove) {
1277                 del = del && !_remove_event (ev);
1278         }
1279
1280         if (del) {
1281                 delete ev;
1282         }
1283 }
1284
1285 framepos_t
1286 Session::compute_stop_limit () const
1287 {
1288         if (!Config->get_stop_at_session_end ()) {
1289                 return max_framepos;
1290         }
1291
1292         if (_slave) {
1293                 return max_framepos;
1294         }
1295
1296         if (preroll_record_punch_enabled ()) {
1297                 return max_framepos;
1298         }
1299
1300         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1301         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1302
1303         if (actively_recording ()) {
1304                 /* permanently recording */
1305                 return max_framepos;
1306         } else if (punching_in && !punching_out) {
1307                 /* punching in but never out */
1308                 return max_framepos;
1309         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
1310                 /* punching in and punching out after session end */
1311                 return max_framepos;
1312         }
1313
1314         return current_end_frame ();
1315 }
1316
1317
1318
1319 /* dedicated thread for signal emission.
1320  *
1321  * while sending cross-thread signals from the process thread
1322  * is fine in general, PBD::Signal's use of boost::function and
1323  * boost:bind can produce a vast overhead which is not
1324  * acceptable for low latency.
1325  *
1326  * This works around the issue by moving the boost overhead
1327  * out of the RT thread. The overall load is probably higher but
1328  * the realtime thread remains unaffected.
1329  */
1330
1331 void
1332 Session::emit_route_signals ()
1333 {
1334         // TODO use RAII to allow using these signals in other places
1335         BatchUpdateStart(); /* EMIT SIGNAL */
1336         boost::shared_ptr<RouteList> r = routes.reader ();
1337         for (RouteList::const_iterator ci = r->begin(); ci != r->end(); ++ci) {
1338                 (*ci)->emit_pending_signals ();
1339         }
1340         BatchUpdateEnd(); /* EMIT SIGNAL */
1341 }
1342
1343 void
1344 Session::emit_thread_start ()
1345 {
1346         if (_rt_thread_active) {
1347                 return;
1348         }
1349         _rt_thread_active = true;
1350
1351         if (pthread_create (&_rt_emit_thread, NULL, emit_thread, this)) {
1352                 _rt_thread_active = false;
1353         }
1354 }
1355
1356 void
1357 Session::emit_thread_terminate ()
1358 {
1359         if (!_rt_thread_active) {
1360                 return;
1361         }
1362         _rt_thread_active = false;
1363
1364         if (pthread_mutex_lock (&_rt_emit_mutex) == 0) {
1365                 pthread_cond_signal (&_rt_emit_cond);
1366                 pthread_mutex_unlock (&_rt_emit_mutex);
1367         }
1368
1369         void *status;
1370         pthread_join (_rt_emit_thread, &status);
1371 }
1372
1373 void *
1374 Session::emit_thread (void *arg)
1375 {
1376         Session *s = static_cast<Session *>(arg);
1377         s->emit_thread_run ();
1378         pthread_exit (0);
1379         return 0;
1380 }
1381
1382 void
1383 Session::emit_thread_run ()
1384 {
1385         pthread_mutex_lock (&_rt_emit_mutex);
1386         while (_rt_thread_active) {
1387                 emit_route_signals();
1388                 pthread_cond_wait (&_rt_emit_cond, &_rt_emit_mutex);
1389         }
1390         pthread_mutex_unlock (&_rt_emit_mutex);
1391 }