libs/ardour/session_process.cc

   1 /*
   2     Copyright (C) 1999-2002 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include <cmath>
  21 #include <cerrno>
  22 #include <algorithm>
  23 #include <unistd.h>
  24
  25 #include "pbd/error.h"
  26 #include "pbd/enumwriter.h"
  27
  28 #include <glibmm/threads.h>
  29
  30 #include "ardour/audioengine.h"
  31 #include "ardour/auditioner.h"
  32 #include "ardour/butler.h"
  33 #include "ardour/cycle_timer.h"
  34 #include "ardour/debug.h"
  35 #include "ardour/disk_reader.h"
  36 #include "ardour/graph.h"
  37 #include "ardour/port.h"
  38 #include "ardour/process_thread.h"
  39 #include "ardour/scene_changer.h"
  40 #include "ardour/session.h"
  41 #include "ardour/slave.h"
  42 #include "ardour/ticker.h"
  43 #include "ardour/types.h"
  44 #include "ardour/vca.h"
  45 #include "ardour/vca_manager.h"
  46
  47 #include "midi++/mmc.h"
  48
  49 #include "pbd/i18n.h"
  50
  51 using namespace ARDOUR;
  52 using namespace PBD;
  53 using namespace std;
  54
  55 /** Called by the audio engine when there is work to be done with JACK.
  56  * @param nframes Number of frames to process.
  57  */
  58
  59 void
  60 Session::process (pframes_t nframes)
  61 {
  62         framepos_t transport_at_start = _transport_frame;
  63
  64         _silent = false;
  65
  66         if (processing_blocked()) {
  67                 _silent = true;
  68                 return;
  69         }
  70
  71         if (non_realtime_work_pending()) {
  72                 if (!_butler->transport_work_requested ()) {
  73                         post_transport ();
  74                 }
  75         }
  76
  77         _engine.main_thread()->get_buffers ();
  78
  79         (this->*process_function) (nframes);
  80
  81         /* realtime-safe meter-position and processor-order changes
  82          *
  83          * ideally this would be done in
  84          * Route::process_output_buffers() but various functions
  85          * callig it hold a _processor_lock reader-lock
  86          */
  87         boost::shared_ptr<RouteList> r = routes.reader ();
  88         for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
  89                 if ((*i)->apply_processor_changes_rt()) {
  90                         _rt_emit_pending = true;
  91                 }
  92         }
  93         if (_rt_emit_pending) {
  94                 if (!_rt_thread_active) {
  95                         emit_route_signals ();
  96                 }
  97                 if (pthread_mutex_trylock (&_rt_emit_mutex) == 0) {
  98                         pthread_cond_signal (&_rt_emit_cond);
  99                         pthread_mutex_unlock (&_rt_emit_mutex);
 100                         _rt_emit_pending = false;
 101                 }
 102         }
 103
 104         _engine.main_thread()->drop_buffers ();
 105
 106         /* deliver MIDI clock. Note that we need to use the transport frame
 107          * position at the start of process(), not the value at the end of
 108          * it. We may already have ticked() because of a transport state
 109          * change, for example.
 110          */
 111
 112         try {
 113                 if (!_silent && !_engine.freewheeling() && Config->get_send_midi_clock() && (transport_speed() == 1.0f || transport_speed() == 0.0f) && midi_clock->has_midi_port()) {
 114                         midi_clock->tick (transport_at_start, nframes);
 115                 }
 116
 117                 _scene_changer->run (transport_at_start, transport_at_start + nframes);
 118
 119         } catch (...) {
 120                 /* don't bother with a message */
 121         }
 122
 123         SendFeedback (); /* EMIT SIGNAL */
 124 }
 125
 126 int
 127 Session::fail_roll (pframes_t nframes)
 128 {
 129         return no_roll (nframes);
 130 }
 131
 132 int
 133 Session::no_roll (pframes_t nframes)
 134 {
 135         PT_TIMING_CHECK (4);
 136
 137         framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
 138         int ret = 0;
 139         int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
 140         boost::shared_ptr<RouteList> r = routes.reader ();
 141
 142         if (_click_io) {
 143                 _click_io->silence (nframes);
 144         }
 145
 146         ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 147
 148         VCAList v = _vca_manager->vcas ();
 149         for (VCAList::const_iterator i = v.begin(); i != v.end(); ++i) {
 150                 (*i)->automation_run (_transport_frame, nframes);
 151         }
 152
 153         if (_process_graph) {
 154                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
 155                 _process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
 156         } else {
 157                 PT_TIMING_CHECK (10);
 158                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 159
 160                         if ((*i)->is_auditioner()) {
 161                                 continue;
 162                         }
 163
 164                         (*i)->set_pending_declick (declick);
 165
 166                         if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending())) {
 167                                 error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 168                                 ret = -1;
 169                                 break;
 170                         }
 171                 }
 172                 PT_TIMING_CHECK (11);
 173         }
 174
 175         PT_TIMING_CHECK (5);
 176         return ret;
 177 }
 178
 179 /** @param need_butler to be set to true by this method if it needs the butler,
 180  *  otherwise it must be left alone.
 181  */
 182 int
 183 Session::process_routes (pframes_t nframes, bool& need_butler)
 184 {
 185         int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
 186         boost::shared_ptr<RouteList> r = routes.reader ();
 187
 188         const framepos_t start_frame = _transport_frame;
 189         const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
 190
 191         VCAList v = _vca_manager->vcas ();
 192         for (VCAList::const_iterator i = v.begin(); i != v.end(); ++i) {
 193                 (*i)->automation_run (start_frame, nframes);
 194         }
 195
 196         _global_locate_pending = locate_pending ();
 197
 198         if (_process_graph) {
 199                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
 200                 if (_process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler) < 0) {
 201                         stop_transport ();
 202                         return -1;
 203                 }
 204         } else {
 205
 206                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 207
 208                         int ret;
 209
 210                         if ((*i)->is_auditioner()) {
 211                                 continue;
 212                         }
 213
 214                         (*i)->set_pending_declick (declick);
 215
 216                         bool b = false;
 217
 218                         if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, b)) < 0) {
 219                                 stop_transport ();
 220                                 return -1;
 221                         }
 222
 223                         if (b) {
 224                                 DEBUG_TRACE (DEBUG::Butler, string_compose ("%1 rolled and needs butler\n", (*i)->name()));
 225                                 need_butler = true;
 226                         }
 227                 }
 228         }
 229
 230         return 0;
 231 }
 232
 233 void
 234 Session::get_track_statistics ()
 235 {
 236         float pworst = 1.0f;
 237         float cworst = 1.0f;
 238
 239         boost::shared_ptr<RouteList> rl = routes.reader();
 240         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 241
 242                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 243
 244                 if (!tr || tr->is_private_route()) {
 245                         continue;
 246                 }
 247
 248                 pworst = min (pworst, tr->playback_buffer_load());
 249                 cworst = min (cworst, tr->capture_buffer_load());
 250         }
 251
 252         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 253         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 254
 255         if (actively_recording()) {
 256                 set_dirty();
 257         }
 258 }
 259
 260 /** Process callback used when the auditioner is not active */
 261 void
 262 Session::process_with_events (pframes_t nframes)
 263 {
 264         PT_TIMING_CHECK (3);
 265
 266         SessionEvent*  ev;
 267         pframes_t      this_nframes;
 268         framepos_t     end_frame;
 269         bool           session_needs_butler = false;
 270         framecnt_t     frames_moved;
 271
 272         /* make sure the auditioner is silent */
 273
 274         if (auditioner) {
 275                 auditioner->silence (nframes);
 276         }
 277
 278         /* handle any pending events */
 279
 280         while (pending_events.read (&ev, 1) == 1) {
 281                 merge_event (ev);
 282         }
 283
 284         /* if we are not in the middle of a state change,
 285            and there are immediate events queued up,
 286            process them.
 287         */
 288
 289         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 290                 SessionEvent *ev = immediate_events.front ();
 291                 immediate_events.pop_front ();
 292                 process_event (ev);
 293         }
 294
 295         /* count in */
 296         if (_transport_speed != 1.0 && _count_in_samples > 0) {
 297                 _count_in_samples = 0;
 298         }
 299
 300         if (_count_in_samples > 0) {
 301                 framecnt_t ns = std::min ((framecnt_t)nframes, _count_in_samples);
 302
 303                 no_roll (ns);
 304                 run_click (_transport_frame - _count_in_samples, ns);
 305
 306                 _count_in_samples -= ns;
 307                 nframes -= ns;
 308
 309                 /* process events.. */
 310                 if (!events.empty() && next_event != events.end()) {
 311                         SessionEvent* this_event = *next_event;
 312                         Events::iterator the_next_one = next_event;
 313                         ++the_next_one;
 314
 315                         while (this_event && this_event->action_frame == _transport_frame) {
 316                                 process_event (this_event);
 317                                 if (the_next_one == events.end()) {
 318                                         this_event = 0;
 319                                 } else {
 320                                         this_event = *the_next_one;
 321                                         ++the_next_one;
 322                                 }
 323                         }
 324                         set_next_event ();
 325                 }
 326
 327                 check_declick_out ();
 328
 329                 if (nframes == 0) {
 330                         return;
 331                 } else {
 332                         _engine.split_cycle (ns);
 333                 }
 334         }
 335
 336         /* Decide on what to do with quarter-frame MTC during this cycle */
 337
 338         bool const was_sending_qf_mtc = _send_qf_mtc;
 339         double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
 340
 341         if (_transport_speed != 0) {
 342                 _send_qf_mtc = (
 343                         Config->get_send_mtc () &&
 344                         _transport_speed >= (1 - tolerance) &&
 345                         _transport_speed <= (1 + tolerance)
 346                         );
 347
 348                 if (_send_qf_mtc && !was_sending_qf_mtc) {
 349                         /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
 350                         _send_timecode_update = true;
 351                 }
 352
 353                 if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
 354                         /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
 355                            a quarter of a second since we sent anything at all, so send a full MTC update
 356                            this cycle.
 357                         */
 358                         _send_timecode_update = true;
 359                 }
 360
 361                 _pframes_since_last_mtc += nframes;
 362         }
 363
 364         /* Events caused a transport change (or we re-started sending
 365          * MTC), so send an MTC Full Frame (Timecode) message.  This
 366          * is sent whether rolling or not, to give slaves an idea of
 367          * ardour time on locates (and allow slow slaves to position
 368          * and prepare for rolling)
 369          */
 370         if (_send_timecode_update) {
 371                 send_full_time_code (_transport_frame, nframes);
 372         }
 373
 374         if (!process_can_proceed()) {
 375                 _silent = true;
 376                 return;
 377         }
 378
 379         if (events.empty() || next_event == events.end()) {
 380                 try_run_lua (nframes); // also during export ?? ->move to process_without_events()
 381                 /* lua scripts may inject events */
 382                 while (_n_lua_scripts > 0 && pending_events.read (&ev, 1) == 1) {
 383                         merge_event (ev);
 384                 }
 385                 if (events.empty() || next_event == events.end()) {
 386                         process_without_events (nframes);
 387                         return;
 388                 }
 389         }
 390
 391         if (locate_pending()) {
 392                 frames_moved = 0;
 393         } else {
 394                 if (_transport_speed == 1.0) {
 395                         frames_moved = (framecnt_t) nframes;
 396                 } else {
 397                         interpolation.set_target_speed (_target_transport_speed);
 398                         interpolation.set_speed (_transport_speed);
 399                         frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 400                 }
 401         }
 402
 403         end_frame = _transport_frame + frames_moved;
 404
 405         {
 406                 SessionEvent* this_event;
 407                 Events::iterator the_next_one;
 408
 409                 if (!process_can_proceed()) {
 410                         _silent = true;
 411                         return;
 412                 }
 413
 414                 if (!_exporting && _slave) {
 415                         if (!follow_slave (nframes)) {
 416                                 cerr << "P-w-E: FS fail\n";
 417                                 return;
 418                         }
 419                 }
 420
 421                 if (_transport_speed == 0) {
 422                         cerr << "P-w-E: ts = 0\n";
 423                         no_roll (nframes);
 424                         return;
 425                 }
 426
 427                 if (!_exporting && !timecode_transmission_suspended()) {
 428                         send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
 429                 }
 430
 431                 ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 432
 433                 framepos_t stop_limit = compute_stop_limit ();
 434
 435                 if (maybe_stop (stop_limit)) {
 436                         cerr << "P-w-E: mebbe stop\n";
 437                         no_roll (nframes);
 438                         return;
 439                 }
 440
 441                 this_event = *next_event;
 442                 the_next_one = next_event;
 443                 ++the_next_one;
 444
 445                 /* yes folks, here it is, the actual loop where we really truly
 446                    process some audio
 447                 */
 448
 449                 while (nframes) {
 450
 451                         this_nframes = nframes; /* real (jack) time relative */
 452                         if (locate_pending()) {
 453                                 frames_moved = 0;
 454                         } else {
 455                                 frames_moved = (framecnt_t) floor (_transport_speed * nframes); /* transport relative */
 456                         }
 457
 458                         /* running an event, position transport precisely to its time */
 459                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 460                                 /* this isn't quite right for reverse play */
 461                                 frames_moved = (framecnt_t) (this_event->action_frame - _transport_frame);
 462                                 this_nframes = abs (floor(frames_moved / _transport_speed));
 463                         }
 464
 465                         try_run_lua (this_nframes);
 466
 467                         if (this_nframes) {
 468
 469                                 click (_transport_frame, this_nframes);
 470
 471                                 if (process_routes (this_nframes, session_needs_butler)) {
 472                                         cerr << "P-w-E: PR fail\n";
 473                                         fail_roll (nframes);
 474                                         return;
 475                                 }
 476
 477                                 get_track_statistics ();
 478
 479                                 nframes -= this_nframes;
 480
 481                                 if (frames_moved < 0) {
 482                                         decrement_transport_position (-frames_moved);
 483                                 } else if (frames_moved) {
 484                                         increment_transport_position (frames_moved);
 485                                 }
 486
 487                                 cerr << "P-w-E: ts now = " << _transport_frame << endl;
 488
 489                                 maybe_stop (stop_limit);
 490                                 check_declick_out ();
 491                         }
 492
 493                         if (nframes > 0) {
 494                                 _engine.split_cycle (this_nframes);
 495                         }
 496
 497                         /* now handle this event and all others scheduled for the same time */
 498
 499                         while (this_event && this_event->action_frame == _transport_frame) {
 500                                 process_event (this_event);
 501
 502                                 if (the_next_one == events.end()) {
 503                                         this_event = 0;
 504                                 } else {
 505                                         this_event = *the_next_one;
 506                                         ++the_next_one;
 507                                 }
 508                         }
 509
 510                         /* if an event left our state changing, do the right thing */
 511
 512                         if (nframes && non_realtime_work_pending()) {
 513                                 cerr << "P-w-E: nrtwp no roll\n";
 514                                 no_roll (nframes);
 515                                 break;
 516                         }
 517
 518                         /* this is necessary to handle the case of seamless looping */
 519                         end_frame = _transport_frame + floor (nframes * _transport_speed);
 520                 }
 521
 522                 set_next_event ();
 523
 524         } /* implicit release of route lock */
 525
 526         cerr << "P-w-E: final ts = " << _transport_frame << endl;
 527
 528         if (session_needs_butler) {
 529                 DEBUG_TRACE (DEBUG::Butler, "p-with-events: session needs butler, call it\n");
 530                 _butler->summon ();
 531         }
 532 }
 533
 534 void
 535 Session::reset_slave_state ()
 536 {
 537         average_slave_delta = 1800;
 538         delta_accumulator_cnt = 0;
 539         have_first_delta_accumulator = false;
 540         _slave_state = Stopped;
 541         DiskReader::set_no_disk_output (false);
 542 }
 543
 544 bool
 545 Session::transport_locked () const
 546 {
 547         Slave* sl = _slave;
 548
 549         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 550                 return true;
 551         }
 552
 553         return false;
 554 }
 555
 556 bool
 557 Session::follow_slave (pframes_t nframes)
 558 {
 559         double slave_speed;
 560         framepos_t slave_transport_frame;
 561         framecnt_t this_delta;
 562         int dir;
 563
 564         if (!_slave->ok()) {
 565                 stop_transport ();
 566                 config.set_external_sync (false);
 567                 goto noroll;
 568         }
 569
 570         _slave->speed_and_position (slave_speed, slave_transport_frame);
 571
 572         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 573
 574         if (!_slave->locked()) {
 575                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 576                 goto noroll;
 577         }
 578
 579         if (slave_transport_frame > _transport_frame) {
 580                 this_delta = slave_transport_frame - _transport_frame;
 581                 dir = 1;
 582         } else {
 583                 this_delta = _transport_frame - slave_transport_frame;
 584                 dir = -1;
 585         }
 586
 587         if (_slave->starting()) {
 588                 slave_speed = 0.0f;
 589         }
 590
 591         if (_slave->is_always_synced() ||
 592                         (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 593                         ) {
 594
 595                 /* if the TC source is synced, then we assume that its
 596                    speed is binary: 0.0 or 1.0
 597                 */
 598
 599                 if (slave_speed != 0.0f) {
 600                         slave_speed = 1.0f;
 601                 }
 602
 603         } else {
 604
 605                 /* if we are chasing and the average delta between us and the
 606                    master gets too big, we want to switch to silent
 607                    motion. so keep track of that here.
 608                 */
 609
 610                 if (_slave_state == Running) {
 611                         calculate_moving_average_of_slave_delta(dir, abs(this_delta));
 612                 }
 613         }
 614
 615         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 616
 617         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 618                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 619
 620
 621         if (_slave_state == Running && !_slave->is_always_synced() && !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)) {
 622
 623                 /* may need to varispeed to sync with slave */
 624
 625                 if (_transport_speed != 0.0f) {
 626
 627                         /*
 628                            note that average_dir is +1 or -1
 629                         */
 630
 631                         float delta;
 632
 633                         if (average_slave_delta == 0) {
 634                                 delta = this_delta;
 635                                 delta *= dir;
 636                         } else {
 637                                 delta = average_slave_delta;
 638                                 delta *= average_dir;
 639                         }
 640
 641 #ifndef NDEBUG
 642                         if (slave_speed != 0.0) {
 643                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 644                                                                            (int) (dir * this_delta),
 645                                                                            slave_speed,
 646                                                                            _transport_speed,
 647                                                                            _transport_frame,
 648                                                                            slave_transport_frame,
 649                                                                            average_slave_delta));
 650                         }
 651 #endif
 652
 653                         if (_slave->give_slave_full_control_over_transport_speed()) {
 654                                 set_transport_speed (slave_speed, 0, false, false);
 655                                 //std::cout << "set speed = " << slave_speed << "\n";
 656                         } else {
 657                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 658                                 request_transport_speed (adjusted_speed);
 659                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 660                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 661                                                                            slave_speed));
 662                         }
 663
 664                         if (!actively_recording() && (framecnt_t) average_slave_delta > _slave->resolution()) {
 665                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("average slave delta %1 greater than slave resolution %2 => no disk output\n", average_slave_delta, _slave->resolution()));
 666                                 /* run routes as normal, but no disk output */
 667                                 DiskReader::set_no_disk_output (true);
 668                                 return true;
 669                         }
 670
 671                         if (!have_first_delta_accumulator) {
 672                                 DEBUG_TRACE (DEBUG::Slave, "waiting for first slave delta accumulator to be ready, no disk output\n");
 673                                 /* run routes as normal, but no disk output */
 674                                 DiskReader::set_no_disk_output (true);
 675                                 return true;
 676                         }
 677                 }
 678         }
 679
 680
 681         if (!have_first_delta_accumulator) {
 682                 DEBUG_TRACE (DEBUG::Slave, "still waiting to compute slave delta, no disk output\n");
 683                 DiskReader::set_no_disk_output (true);
 684         } else {
 685                 DiskReader::set_no_disk_output (false);
 686         }
 687
 688         if ((_slave_state == Running) && (0 == (post_transport_work () & ~PostTransportSpeed))) {
 689                 /* speed is set, we're locked, and good to go */
 690                 return true;
 691         }
 692
 693   noroll:
 694         /* don't move at all */
 695         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 696         no_roll (nframes);
 697         return false;
 698 }
 699
 700 void
 701 Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta)
 702 {
 703         if (delta_accumulator_cnt >= delta_accumulator_size) {
 704                 have_first_delta_accumulator = true;
 705                 delta_accumulator_cnt = 0;
 706         }
 707
 708         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 709                 delta_accumulator[delta_accumulator_cnt++] = (framecnt_t) dir *  (framecnt_t) this_delta;
 710         }
 711
 712         if (have_first_delta_accumulator) {
 713                 average_slave_delta = 0L;
 714                 for (int i = 0; i < delta_accumulator_size; ++i) {
 715                         average_slave_delta += delta_accumulator[i];
 716                 }
 717                 average_slave_delta /= (int32_t) delta_accumulator_size;
 718                 if (average_slave_delta < 0L) {
 719                         average_dir = -1;
 720                         average_slave_delta = average_slave_delta;
 721                 } else {
 722                         average_dir = 1;
 723                 }
 724         }
 725 }
 726
 727 void
 728 Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
 729 {
 730         if (slave_speed != 0.0f) {
 731
 732                 /* slave is running */
 733
 734                 switch (_slave_state) {
 735                 case Stopped:
 736                         if (_slave->requires_seekahead()) {
 737                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 738                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 739                                 /* we can call locate() here because we are in process context */
 740                                 locate (slave_wait_end, false, false);
 741                                 _slave_state = Waiting;
 742
 743                         } else {
 744
 745                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_frame));
 746
 747                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 748                                 average_slave_delta = 0L;
 749
 750                                 Location* al = _locations->auto_loop_location();
 751
 752                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 753                                         // cancel looping
 754                                         request_play_loop(false);
 755                                 }
 756
 757                                 if (slave_transport_frame != _transport_frame) {
 758                                         DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_frame, slave_transport_frame));
 759                                         locate (slave_transport_frame, false, false);
 760                                 }
 761                                 _slave_state = Running;
 762                         }
 763                         break;
 764
 765                 case Waiting:
 766                 default:
 767                         break;
 768                 }
 769
 770                 if (_slave_state == Waiting) {
 771
 772                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 773
 774                         if (slave_transport_frame >= slave_wait_end) {
 775
 776                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 777
 778                                 _slave_state = Running;
 779
 780                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 781                                    precisely with the master.
 782                                 */
 783
 784
 785                                 bool ok = true;
 786                                 framecnt_t frame_delta = slave_transport_frame - _transport_frame;
 787
 788                                 boost::shared_ptr<RouteList> rl = routes.reader();
 789                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 790                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 791                                         if (tr && !tr->can_internal_playback_seek (frame_delta)) {
 792                                                 ok = false;
 793                                                 break;
 794                                         }
 795                                 }
 796
 797                                 if (ok) {
 798                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 799                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 800                                                 if (tr) {
 801                                                         tr->internal_playback_seek (frame_delta);
 802                                                 }
 803                                         }
 804                                         _transport_frame += frame_delta;
 805
 806                                 } else {
 807                                         cerr << "cannot micro-seek\n";
 808                                         /* XXX what? */
 809                                 }
 810                         }
 811                 }
 812
 813                 if (_slave_state == Running && _transport_speed == 0.0f) {
 814                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 815                         start_transport ();
 816                 }
 817
 818         } else { // slave_speed is 0
 819
 820                 /* slave has stopped */
 821
 822                 if (_transport_speed != 0.0f) {
 823                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 824                         stop_transport ();
 825                 }
 826
 827                 if (slave_transport_frame != _transport_frame) {
 828                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 829                         force_locate (slave_transport_frame, false);
 830                 }
 831
 832                 reset_slave_state();
 833         }
 834 }
 835
 836 void
 837 Session::process_without_events (pframes_t nframes)
 838 {
 839         bool session_needs_butler = false;
 840         framecnt_t frames_moved;
 841
 842         if (!process_can_proceed()) {
 843                 _silent = true;
 844                 return;
 845         }
 846
 847         if (!_exporting && _slave) {
 848                 if (!follow_slave (nframes)) {
 849                         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame, 0, 0 , nframes);
 850                         cerr << "p-WO-E: FS fail\n";
 851                         return;
 852                 }
 853         }
 854
 855         if (_transport_speed == 0) {
 856                 cerr << "p-WO-E: ts = 0\n";
 857                 no_roll (nframes);
 858                 return;
 859         }
 860
 861         if (locate_pending()) {
 862                 cerr << "p-WO-E: locate still pending\n";
 863                 frames_moved = 0;
 864         } else {
 865                 if (_transport_speed == 1.0) {
 866                         frames_moved = (framecnt_t) nframes;
 867                 } else {
 868                         interpolation.set_target_speed (_target_transport_speed);
 869                         interpolation.set_speed (_transport_speed);
 870                         frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 871                         cerr << "p-WO-E: current speed : " << _transport_speed << " interpolate says " << frames_moved << endl;
 872                 }
 873         }
 874
 875         cerr << "p-WO-E: will move " << frames_moved << endl;
 876
 877         if (!_exporting && !timecode_transmission_suspended()) {
 878                 send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
 879         }
 880
 881         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, _target_transport_speed, _transport_speed, nframes);
 882
 883         framepos_t const stop_limit = compute_stop_limit ();
 884
 885         if (maybe_stop (stop_limit)) {
 886                 cerr << "p-WO-E: mebbe stop\n";
 887                 no_roll (nframes);
 888                 return;
 889         }
 890
 891         if (maybe_sync_start (nframes)) {
 892                 cerr << "p-WO-E: sync start said no\n";
 893                 return;
 894         }
 895
 896         click (_transport_frame, nframes);
 897
 898         if (process_routes (nframes, session_needs_butler)) {
 899                 cerr << "p-WO-E: pr failed\n";
 900                 fail_roll (nframes);
 901                 return;
 902         }
 903
 904         get_track_statistics ();
 905
 906         if (frames_moved < 0) {
 907                 decrement_transport_position (-frames_moved);
 908         } else if (frames_moved) {
 909                 increment_transport_position (frames_moved);
 910         }
 911
 912         cerr << "p-WO-E: ts now " << _transport_frame << endl;
 913
 914         maybe_stop (stop_limit);
 915         check_declick_out ();
 916
 917         if (session_needs_butler) {
 918                 DEBUG_TRACE (DEBUG::Butler, "p-without-events: session needs butler, call it\n");
 919                 _butler->summon ();
 920         }
 921 }
 922
 923 /** Process callback used when the auditioner is active.
 924  * @param nframes number of frames to process.
 925  */
 926 void
 927 Session::process_audition (pframes_t nframes)
 928 {
 929         SessionEvent* ev;
 930         boost::shared_ptr<RouteList> r = routes.reader ();
 931
 932         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 933                 if (!(*i)->is_auditioner()) {
 934                         (*i)->silence (nframes);
 935                 }
 936         }
 937
 938         /* run the auditioner, and if it says we need butler service, ask for it */
 939
 940         if (auditioner->play_audition (nframes) > 0) {
 941                 DEBUG_TRACE (DEBUG::Butler, "auditioner needs butler, call it\n");
 942                 _butler->summon ();
 943         }
 944
 945         /* if using a monitor section, run it because otherwise we don't hear anything */
 946
 947         if (_monitor_out && auditioner->needs_monitor()) {
 948                 _monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
 949         }
 950
 951         /* handle pending events */
 952
 953         while (pending_events.read (&ev, 1) == 1) {
 954                 merge_event (ev);
 955         }
 956
 957         /* if we are not in the middle of a state change,
 958            and there are immediate events queued up,
 959            process them.
 960         */
 961
 962         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 963                 SessionEvent *ev = immediate_events.front ();
 964                 immediate_events.pop_front ();
 965                 process_event (ev);
 966         }
 967
 968         if (!auditioner->auditioning()) {
 969                 /* auditioner no longer active, so go back to the normal process callback */
 970                 process_function = &Session::process_with_events;
 971         }
 972 }
 973
 974 bool
 975 Session::maybe_sync_start (pframes_t & nframes)
 976 {
 977         pframes_t sync_offset;
 978
 979         if (!waiting_for_sync_offset) {
 980                 return false;
 981         }
 982
 983         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 984
 985                 /* generate silence up to the sync point, then
 986                    adjust nframes + offset to reflect whatever
 987                    is left to do.
 988                 */
 989
 990                 no_roll (sync_offset);
 991                 nframes -= sync_offset;
 992                 Port::increment_global_port_buffer_offset (sync_offset);
 993                 waiting_for_sync_offset = false;
 994
 995                 if (nframes == 0) {
 996                         return true; // done, nothing left to process
 997                 }
 998
 999         } else {
1000
1001                 /* sync offset point is not within this process()
1002                    cycle, so just generate silence. and don't bother
1003                    with any fancy stuff here, just the minimal silence.
1004                 */
1005
1006                 _silent = true;
1007
1008                 if (Config->get_locate_while_waiting_for_sync()) {
1009                         if (micro_locate (nframes)) {
1010                                 /* XXX ERROR !!! XXX */
1011                         }
1012                 }
1013
1014                 return true; // done, nothing left to process
1015         }
1016
1017         return false;
1018 }
1019
1020 void
1021 Session::queue_event (SessionEvent* ev)
1022 {
1023         if (_state_of_the_state & Deletion) {
1024                 return;
1025         } else if (_state_of_the_state & Loading) {
1026                 merge_event (ev);
1027         } else {
1028                 Glib::Threads::Mutex::Lock lm (rb_write_lock);
1029                 pending_events.write (&ev, 1);
1030         }
1031 }
1032
1033 void
1034 Session::set_next_event ()
1035 {
1036         if (events.empty()) {
1037                 next_event = events.end();
1038                 return;
1039         }
1040
1041         if (next_event == events.end()) {
1042                 next_event = events.begin();
1043         }
1044
1045         if ((*next_event)->action_frame > _transport_frame) {
1046                 next_event = events.begin();
1047         }
1048
1049         for (; next_event != events.end(); ++next_event) {
1050                 if ((*next_event)->action_frame >= _transport_frame) {
1051                         break;
1052                 }
1053         }
1054 }
1055
1056 void
1057 Session::process_event (SessionEvent* ev)
1058 {
1059         bool remove = true;
1060         bool del = true;
1061
1062         /* if we're in the middle of a state change (i.e. waiting
1063            for the butler thread to complete the non-realtime
1064            part of the change), we'll just have to queue this
1065            event for a time when the change is complete.
1066         */
1067
1068         if (non_realtime_work_pending()) {
1069
1070                 /* except locates, which we have the capability to handle */
1071
1072                 if (ev->type != SessionEvent::Locate) {
1073                         immediate_events.insert (immediate_events.end(), ev);
1074                         _remove_event (ev);
1075                         return;
1076                 }
1077         }
1078
1079         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
1080
1081         switch (ev->type) {
1082         case SessionEvent::SetLoop:
1083                 set_play_loop (ev->yes_or_no, ev->speed);
1084                 break;
1085
1086         case SessionEvent::AutoLoop:
1087                 if (play_loop) {
1088                         /* roll after locate, do not flush, set "with loop"
1089                            true only if we are seamless looping
1090                         */
1091                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
1092                 }
1093                 remove = false;
1094                 del = false;
1095                 break;
1096
1097         case SessionEvent::AutoLoopDeclick:
1098                 if (play_loop) {
1099                         /* Request a declick fade-out and a fade-in; the fade-out will happen
1100                            at the end of the loop, and the fade-in at the start.
1101                         */
1102                         transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
1103                 }
1104                 remove = false;
1105                 del = false;
1106                 break;
1107
1108         case SessionEvent::Locate:
1109                 if (ev->yes_or_no) {
1110                         /* args: do not roll after locate, do flush, not with loop */
1111                         locate (ev->target_frame, false, true, false);
1112                 } else {
1113                         /* args: do not roll after locate, do flush, not with loop */
1114                         start_locate (ev->target_frame, false, true, false);
1115                 }
1116                 _send_timecode_update = true;
1117                 break;
1118
1119         case SessionEvent::LocateRoll:
1120                 if (ev->yes_or_no) {
1121                         /* args: roll after locate, do flush, not with loop */
1122                         locate (ev->target_frame, true, true, false);
1123                 } else {
1124                         /* args: roll after locate, do flush, not with loop */
1125                         start_locate (ev->target_frame, true, true, false);
1126                 }
1127                 _send_timecode_update = true;
1128                 break;
1129
1130         case SessionEvent::Skip:
1131                 if (Config->get_skip_playback()) {
1132                         start_locate (ev->target_frame, true, true, false);
1133                         _send_timecode_update = true;
1134                 }
1135                 remove = false;
1136                 del = false;
1137                 break;
1138
1139         case SessionEvent::LocateRollLocate:
1140                 // locate is handled by ::request_roll_at_and_return()
1141                 _requested_return_frame = ev->target_frame;
1142                 request_locate (ev->target2_frame, true);
1143                 break;
1144
1145
1146         case SessionEvent::SetTransportSpeed:
1147                 set_transport_speed (ev->speed, ev->target_frame, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
1148                 break;
1149
1150         case SessionEvent::PunchIn:
1151                 // cerr << "PunchIN at " << transport_frame() << endl;
1152                 if (config.get_punch_in() && record_status() == Enabled && !preroll_record_punch_enabled()) {
1153                         enable_record ();
1154                 }
1155                 remove = false;
1156                 del = false;
1157                 break;
1158
1159         case SessionEvent::PunchOut:
1160                 // cerr << "PunchOUT at " << transport_frame() << endl;
1161                 if (config.get_punch_out() && !preroll_record_punch_enabled()) {
1162                         step_back_from_record ();
1163                 }
1164                 remove = false;
1165                 del = false;
1166                 break;
1167
1168         case SessionEvent::RecordStart:
1169                 if (preroll_record_punch_enabled() && record_status() == Enabled) {
1170                         enable_record ();
1171                 }
1172                 remove = false;
1173                 del = false;
1174                 break;
1175
1176         case SessionEvent::StopOnce:
1177                 if (!non_realtime_work_pending()) {
1178                         _clear_event_type (SessionEvent::StopOnce);
1179                         stop_transport (ev->yes_or_no);
1180                 }
1181                 remove = false;
1182                 del = false;
1183                 break;
1184
1185         case SessionEvent::RangeStop:
1186                 if (!non_realtime_work_pending()) {
1187                         stop_transport (ev->yes_or_no);
1188                 }
1189                 remove = false;
1190                 del = false;
1191                 break;
1192
1193         case SessionEvent::RangeLocate:
1194                 /* args: roll after locate, do flush, not with loop */
1195                 start_locate (ev->target_frame, true, true, false);
1196                 remove = false;
1197                 del = false;
1198                 break;
1199
1200         case SessionEvent::Overwrite:
1201                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1202                 break;
1203
1204         case SessionEvent::SetSyncSource:
1205                 DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
1206                 use_sync_source (ev->slave);
1207                 break;
1208
1209         case SessionEvent::Audition:
1210                 set_audition (ev->region);
1211                 // drop reference to region
1212                 ev->region.reset ();
1213                 break;
1214
1215         case SessionEvent::SetPlayAudioRange:
1216                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1217                 break;
1218
1219         case SessionEvent::CancelPlayAudioRange:
1220                 unset_play_range();
1221                 break;
1222
1223         case SessionEvent::RealTimeOperation:
1224                 process_rtop (ev);
1225                 del = false; // other side of RT request needs to clean up
1226                 break;
1227
1228         case SessionEvent::AdjustPlaybackBuffering:
1229                 schedule_playback_buffering_adjustment ();
1230                 break;
1231
1232         case SessionEvent::AdjustCaptureBuffering:
1233                 schedule_capture_buffering_adjustment ();
1234                 break;
1235
1236         case SessionEvent::SetTimecodeTransmission:
1237                 g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
1238                 break;
1239
1240         default:
1241           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1242                 abort(); /*NOTREACHED*/
1243                 break;
1244         };
1245
1246         if (remove) {
1247                 del = del && !_remove_event (ev);
1248         }
1249
1250         if (del) {
1251                 delete ev;
1252         }
1253 }
1254
1255 framepos_t
1256 Session::compute_stop_limit () const
1257 {
1258         if (!Config->get_stop_at_session_end ()) {
1259                 return max_framepos;
1260         }
1261
1262         if (_slave) {
1263                 return max_framepos;
1264         }
1265
1266         if (preroll_record_punch_enabled ()) {
1267                 return max_framepos;
1268         }
1269
1270         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1271         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1272
1273         if (actively_recording ()) {
1274                 /* permanently recording */
1275                 return max_framepos;
1276         } else if (punching_in && !punching_out) {
1277                 /* punching in but never out */
1278                 return max_framepos;
1279         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
1280                 /* punching in and punching out after session end */
1281                 return max_framepos;
1282         }
1283
1284         return current_end_frame ();
1285 }
1286
1287
1288
1289 /* dedicated thread for signal emission.
1290  *
1291  * while sending cross-thread signals from the process thread
1292  * is fine in general, PBD::Signal's use of boost::function and
1293  * boost:bind can produce a vast overhead which is not
1294  * acceptable for low latency.
1295  *
1296  * This works around the issue by moving the boost overhead
1297  * out of the RT thread. The overall load is probably higher but
1298  * the realtime thread remains unaffected.
1299  */
1300
1301 void
1302 Session::emit_route_signals ()
1303 {
1304         // TODO use RAII to allow using these signals in other places
1305         BatchUpdateStart(); /* EMIT SIGNAL */
1306         boost::shared_ptr<RouteList> r = routes.reader ();
1307         for (RouteList::const_iterator ci = r->begin(); ci != r->end(); ++ci) {
1308                 (*ci)->emit_pending_signals ();
1309         }
1310         BatchUpdateEnd(); /* EMIT SIGNAL */
1311 }
1312
1313 void
1314 Session::emit_thread_start ()
1315 {
1316         if (_rt_thread_active) {
1317                 return;
1318         }
1319         _rt_thread_active = true;
1320
1321         if (pthread_create (&_rt_emit_thread, NULL, emit_thread, this)) {
1322                 _rt_thread_active = false;
1323         }
1324 }
1325
1326 void
1327 Session::emit_thread_terminate ()
1328 {
1329         if (!_rt_thread_active) {
1330                 return;
1331         }
1332         _rt_thread_active = false;
1333
1334         if (pthread_mutex_lock (&_rt_emit_mutex) == 0) {
1335                 pthread_cond_signal (&_rt_emit_cond);
1336                 pthread_mutex_unlock (&_rt_emit_mutex);
1337         }
1338
1339         void *status;
1340         pthread_join (_rt_emit_thread, &status);
1341 }
1342
1343 void *
1344 Session::emit_thread (void *arg)
1345 {
1346         Session *s = static_cast<Session *>(arg);
1347         s->emit_thread_run ();
1348         pthread_exit (0);
1349         return 0;
1350 }
1351
1352 void
1353 Session::emit_thread_run ()
1354 {
1355         pthread_mutex_lock (&_rt_emit_mutex);
1356         while (_rt_thread_active) {
1357                 emit_route_signals();
1358                 pthread_cond_wait (&_rt_emit_cond, &_rt_emit_mutex);
1359         }
1360         pthread_mutex_unlock (&_rt_emit_mutex);
1361 }