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 samples to process.
  57  */
  58
  59 void
  60 Session::process (pframes_t nframes)
  61 {
  62         samplepos_t transport_at_start = _transport_sample;
  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 sample
 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         samplepos_t end_sample = _transport_sample + 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_sample, end_sample, _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_sample, 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_sample, end_sample, 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_sample, end_sample, 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 samplepos_t start_sample = _transport_sample;
 189         const samplepos_t end_sample = _transport_sample + 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_sample, 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_sample, end_sample, 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_sample, end_sample, 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         samplepos_t     end_sample;
 269         bool           session_needs_butler = false;
 270         samplecnt_t     samples_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                 samplecnt_t ns = std::min ((samplecnt_t)nframes, _count_in_samples);
 302
 303                 no_roll (ns);
 304                 run_click (_transport_sample - _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_sample == _transport_sample) {
 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 > (sample_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_sample, 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 (_transport_speed == 1.0) {
 392                 samples_moved = (samplecnt_t) nframes;
 393         } else {
 394                 interpolation.set_target_speed (_target_transport_speed);
 395                 interpolation.set_speed (_transport_speed);
 396                 samples_moved = (samplecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 397         }
 398
 399         end_sample = _transport_sample + samples_moved;
 400
 401         {
 402                 SessionEvent* this_event;
 403                 Events::iterator the_next_one;
 404
 405                 if (!process_can_proceed()) {
 406                         _silent = true;
 407                         return;
 408                 }
 409
 410                 if (!_exporting && _slave) {
 411                         if (!follow_slave (nframes)) {
 412                                 return;
 413                         }
 414                 }
 415
 416                 if (_transport_speed == 0) {
 417                         no_roll (nframes);
 418                         return;
 419                 }
 420
 421                 if (!_exporting && !timecode_transmission_suspended()) {
 422                         send_midi_time_code_for_cycle (_transport_sample, end_sample, nframes);
 423                 }
 424
 425                 ltc_tx_send_time_code_for_cycle (_transport_sample, end_sample, _target_transport_speed, _transport_speed, nframes);
 426
 427                 samplepos_t stop_limit = compute_stop_limit ();
 428
 429                 if (maybe_stop (stop_limit)) {
 430                         no_roll (nframes);
 431                         return;
 432                 }
 433
 434                 this_event = *next_event;
 435                 the_next_one = next_event;
 436                 ++the_next_one;
 437
 438                 /* yes folks, here it is, the actual loop where we really truly
 439                    process some audio
 440                 */
 441
 442                 while (nframes) {
 443
 444                         this_nframes = nframes; /* real (jack) time relative */
 445                         samples_moved = (samplecnt_t) floor (_transport_speed * nframes); /* transport relative */
 446
 447                         /* running an event, position transport precisely to its time */
 448                         if (this_event && this_event->action_sample <= end_sample && this_event->action_sample >= _transport_sample) {
 449                                 /* this isn't quite right for reverse play */
 450                                 samples_moved = (samplecnt_t) (this_event->action_sample - _transport_sample);
 451                                 this_nframes = abs (floor(samples_moved / _transport_speed));
 452                         }
 453
 454                         try_run_lua (this_nframes);
 455
 456                         if (this_nframes) {
 457
 458                                 click (_transport_sample, this_nframes);
 459
 460                                 if (process_routes (this_nframes, session_needs_butler)) {
 461                                         fail_roll (nframes);
 462                                         return;
 463                                 }
 464
 465                                 get_track_statistics ();
 466
 467                                 nframes -= this_nframes;
 468
 469                                 if (samples_moved < 0) {
 470                                         decrement_transport_position (-samples_moved);
 471                                 } else if (samples_moved) {
 472                                         increment_transport_position (samples_moved);
 473                                 }
 474
 475                                 maybe_stop (stop_limit);
 476                                 check_declick_out ();
 477                         }
 478
 479                         if (nframes > 0) {
 480                                 _engine.split_cycle (this_nframes);
 481                         }
 482
 483                         /* now handle this event and all others scheduled for the same time */
 484
 485                         while (this_event && this_event->action_sample == _transport_sample) {
 486                                 process_event (this_event);
 487
 488                                 if (the_next_one == events.end()) {
 489                                         this_event = 0;
 490                                 } else {
 491                                         this_event = *the_next_one;
 492                                         ++the_next_one;
 493                                 }
 494                         }
 495
 496                         /* if an event left our state changing, do the right thing */
 497
 498                         if (nframes && non_realtime_work_pending()) {
 499                                 no_roll (nframes);
 500                                 break;
 501                         }
 502
 503                         /* this is necessary to handle the case of seamless looping */
 504                         end_sample = _transport_sample + floor (nframes * _transport_speed);
 505                 }
 506
 507                 set_next_event ();
 508
 509         } /* implicit release of route lock */
 510
 511         if (session_needs_butler) {
 512                 DEBUG_TRACE (DEBUG::Butler, "p-with-events: session needs butler, call it\n");
 513                 _butler->summon ();
 514         }
 515 }
 516
 517 void
 518 Session::reset_slave_state ()
 519 {
 520         average_slave_delta = 1800;
 521         delta_accumulator_cnt = 0;
 522         have_first_delta_accumulator = false;
 523         _slave_state = Stopped;
 524         DiskReader::set_no_disk_output (false);
 525 }
 526
 527 bool
 528 Session::transport_locked () const
 529 {
 530         Slave* sl = _slave;
 531
 532         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 533                 return true;
 534         }
 535
 536         return false;
 537 }
 538
 539 bool
 540 Session::follow_slave (pframes_t nframes)
 541 {
 542         double slave_speed;
 543         samplepos_t slave_transport_sample;
 544         samplecnt_t this_delta;
 545         int dir;
 546
 547         if (!_slave->ok()) {
 548                 stop_transport ();
 549                 config.set_external_sync (false);
 550                 goto noroll;
 551         }
 552
 553         _slave->speed_and_position (slave_speed, slave_transport_sample);
 554
 555         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_sample, slave_speed));
 556
 557         if (!_slave->locked()) {
 558                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 559                 goto noroll;
 560         }
 561
 562         if (slave_transport_sample > _transport_sample) {
 563                 this_delta = slave_transport_sample - _transport_sample;
 564                 dir = 1;
 565         } else {
 566                 this_delta = _transport_sample - slave_transport_sample;
 567                 dir = -1;
 568         }
 569
 570         if (_slave->starting()) {
 571                 slave_speed = 0.0f;
 572         }
 573
 574         if (_slave->is_always_synced() ||
 575                         (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 576                         ) {
 577
 578                 /* if the TC source is synced, then we assume that its
 579                    speed is binary: 0.0 or 1.0
 580                 */
 581
 582                 if (slave_speed != 0.0f) {
 583                         slave_speed = 1.0f;
 584                 }
 585
 586         } else {
 587
 588                 /* if we are chasing and the average delta between us and the
 589                    master gets too big, we want to switch to silent
 590                    motion. so keep track of that here.
 591                 */
 592
 593                 if (_slave_state == Running) {
 594                         calculate_moving_average_of_slave_delta(dir, abs(this_delta));
 595                 }
 596         }
 597
 598         track_slave_state (slave_speed, slave_transport_sample, this_delta);
 599
 600         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 601                                                    _slave_state, slave_transport_sample, slave_speed, this_delta, average_slave_delta));
 602
 603
 604         if (_slave_state == Running && !_slave->is_always_synced() && !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)) {
 605
 606                 /* may need to varispeed to sync with slave */
 607
 608                 if (_transport_speed != 0.0f) {
 609
 610                         /*
 611                            note that average_dir is +1 or -1
 612                         */
 613
 614                         float delta;
 615
 616                         if (average_slave_delta == 0) {
 617                                 delta = this_delta;
 618                                 delta *= dir;
 619                         } else {
 620                                 delta = average_slave_delta;
 621                                 delta *= average_dir;
 622                         }
 623
 624 #ifndef NDEBUG
 625                         if (slave_speed != 0.0) {
 626                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 627                                                                            (int) (dir * this_delta),
 628                                                                            slave_speed,
 629                                                                            _transport_speed,
 630                                                                            _transport_sample,
 631                                                                            slave_transport_sample,
 632                                                                            average_slave_delta));
 633                         }
 634 #endif
 635
 636                         if (_slave->give_slave_full_control_over_transport_speed()) {
 637                                 set_transport_speed (slave_speed, 0, false, false);
 638                                 //std::cout << "set speed = " << slave_speed << "\n";
 639                         } else {
 640                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_sample_rate)));
 641                                 request_transport_speed (adjusted_speed);
 642                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 643                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 644                                                                            slave_speed));
 645                         }
 646
 647                         if (!actively_recording() && (samplecnt_t) average_slave_delta > _slave->resolution()) {
 648                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("average slave delta %1 greater than slave resolution %2 => no disk output\n", average_slave_delta, _slave->resolution()));
 649                                 /* run routes as normal, but no disk output */
 650                                 DiskReader::set_no_disk_output (true);
 651                                 return true;
 652                         }
 653
 654                         if (!have_first_delta_accumulator) {
 655                                 DEBUG_TRACE (DEBUG::Slave, "waiting for first slave delta accumulator to be ready, no disk output\n");
 656                                 /* run routes as normal, but no disk output */
 657                                 DiskReader::set_no_disk_output (true);
 658                                 return true;
 659                         }
 660                 }
 661         }
 662
 663
 664         if (!have_first_delta_accumulator) {
 665                 DEBUG_TRACE (DEBUG::Slave, "still waiting to compute slave delta, no disk output\n");
 666                 DiskReader::set_no_disk_output (true);
 667         } else {
 668                 DiskReader::set_no_disk_output (false);
 669         }
 670
 671         if ((_slave_state == Running) && (0 == (post_transport_work () & ~PostTransportSpeed))) {
 672                 /* speed is set, we're locked, and good to go */
 673                 return true;
 674         }
 675
 676   noroll:
 677         /* don't move at all */
 678         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 679         no_roll (nframes);
 680         return false;
 681 }
 682
 683 void
 684 Session::calculate_moving_average_of_slave_delta (int dir, samplecnt_t this_delta)
 685 {
 686         if (delta_accumulator_cnt >= delta_accumulator_size) {
 687                 have_first_delta_accumulator = true;
 688                 delta_accumulator_cnt = 0;
 689         }
 690
 691         if (delta_accumulator_cnt != 0 || this_delta < _current_sample_rate) {
 692                 delta_accumulator[delta_accumulator_cnt++] = (samplecnt_t) dir *  (samplecnt_t) this_delta;
 693         }
 694
 695         if (have_first_delta_accumulator) {
 696                 average_slave_delta = 0L;
 697                 for (int i = 0; i < delta_accumulator_size; ++i) {
 698                         average_slave_delta += delta_accumulator[i];
 699                 }
 700                 average_slave_delta /= (int32_t) delta_accumulator_size;
 701                 if (average_slave_delta < 0L) {
 702                         average_dir = -1;
 703                         average_slave_delta = average_slave_delta;
 704                 } else {
 705                         average_dir = 1;
 706                 }
 707         }
 708 }
 709
 710 void
 711 Session::track_slave_state (float slave_speed, samplepos_t slave_transport_sample, samplecnt_t /*this_delta*/)
 712 {
 713         if (slave_speed != 0.0f) {
 714
 715                 /* slave is running */
 716
 717                 switch (_slave_state) {
 718                 case Stopped:
 719                         if (_slave->requires_seekahead()) {
 720                                 slave_wait_end = slave_transport_sample + _slave->seekahead_distance ();
 721                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 722                                 /* we can call locate() here because we are in process context */
 723                                 locate (slave_wait_end, false, false);
 724                                 _slave_state = Waiting;
 725
 726                         } else {
 727
 728                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_sample));
 729
 730                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 731                                 average_slave_delta = 0L;
 732
 733                                 Location* al = _locations->auto_loop_location();
 734
 735                                 if (al && play_loop && (slave_transport_sample < al->start() || slave_transport_sample > al->end())) {
 736                                         // cancel looping
 737                                         request_play_loop(false);
 738                                 }
 739
 740                                 if (slave_transport_sample != _transport_sample) {
 741                                         DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_sample, slave_transport_sample));
 742                                         locate (slave_transport_sample, false, false);
 743                                 }
 744                                 _slave_state = Running;
 745                         }
 746                         break;
 747
 748                 case Waiting:
 749                 default:
 750                         break;
 751                 }
 752
 753                 if (_slave_state == Waiting) {
 754
 755                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_sample));
 756
 757                         if (slave_transport_sample >= slave_wait_end) {
 758
 759                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_sample, _transport_sample));
 760
 761                                 _slave_state = Running;
 762
 763                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 764                                    precisely with the master.
 765                                 */
 766
 767
 768                                 bool ok = true;
 769                                 samplecnt_t sample_delta = slave_transport_sample - _transport_sample;
 770
 771                                 boost::shared_ptr<RouteList> rl = routes.reader();
 772                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 773                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 774                                         if (tr && !tr->can_internal_playback_seek (sample_delta)) {
 775                                                 ok = false;
 776                                                 break;
 777                                         }
 778                                 }
 779
 780                                 if (ok) {
 781                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 782                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 783                                                 if (tr) {
 784                                                         tr->internal_playback_seek (sample_delta);
 785                                                 }
 786                                         }
 787                                         _transport_sample += sample_delta;
 788
 789                                 } else {
 790                                         cerr << "cannot micro-seek\n";
 791                                         /* XXX what? */
 792                                 }
 793                         }
 794                 }
 795
 796                 if (_slave_state == Running && _transport_speed == 0.0f) {
 797                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 798                         start_transport ();
 799                 }
 800
 801         } else { // slave_speed is 0
 802
 803                 /* slave has stopped */
 804
 805                 if (_transport_speed != 0.0f) {
 806                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 sample %2 tf %3\n", slave_speed, slave_transport_sample, _transport_sample));
 807                         stop_transport ();
 808                 }
 809
 810                 if (slave_transport_sample != _transport_sample) {
 811                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_sample));
 812                         force_locate (slave_transport_sample, false);
 813                 }
 814
 815                 reset_slave_state();
 816         }
 817 }
 818
 819 void
 820 Session::process_without_events (pframes_t nframes)
 821 {
 822         bool session_needs_butler = false;
 823         samplecnt_t samples_moved;
 824
 825         if (!process_can_proceed()) {
 826                 _silent = true;
 827                 return;
 828         }
 829
 830         if (!_exporting && _slave) {
 831                 if (!follow_slave (nframes)) {
 832                         ltc_tx_send_time_code_for_cycle (_transport_sample, _transport_sample, 0, 0 , nframes);
 833                         return;
 834                 }
 835         }
 836
 837         if (_transport_speed == 0) {
 838                 no_roll (nframes);
 839                 return;
 840         }
 841
 842         if (_transport_speed == 1.0) {
 843                 samples_moved = (samplecnt_t) nframes;
 844         } else {
 845                 interpolation.set_target_speed (_target_transport_speed);
 846                 interpolation.set_speed (_transport_speed);
 847                 samples_moved = (samplecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 848         }
 849
 850         if (!_exporting && !timecode_transmission_suspended()) {
 851                 send_midi_time_code_for_cycle (_transport_sample, _transport_sample + samples_moved, nframes);
 852         }
 853
 854         ltc_tx_send_time_code_for_cycle (_transport_sample, _transport_sample + samples_moved, _target_transport_speed, _transport_speed, nframes);
 855
 856         samplepos_t const stop_limit = compute_stop_limit ();
 857
 858         if (maybe_stop (stop_limit)) {
 859                 no_roll (nframes);
 860                 return;
 861         }
 862
 863         if (maybe_sync_start (nframes)) {
 864                 return;
 865         }
 866
 867         click (_transport_sample, nframes);
 868
 869         if (process_routes (nframes, session_needs_butler)) {
 870                 fail_roll (nframes);
 871                 return;
 872         }
 873
 874         get_track_statistics ();
 875
 876         if (samples_moved < 0) {
 877                 decrement_transport_position (-samples_moved);
 878         } else if (samples_moved) {
 879                 increment_transport_position (samples_moved);
 880         }
 881
 882         maybe_stop (stop_limit);
 883         check_declick_out ();
 884
 885         if (session_needs_butler) {
 886                 DEBUG_TRACE (DEBUG::Butler, "p-without-events: session needs butler, call it\n");
 887                 _butler->summon ();
 888         }
 889 }
 890
 891 /** Process callback used when the auditioner is active.
 892  * @param nframes number of samples to process.
 893  */
 894 void
 895 Session::process_audition (pframes_t nframes)
 896 {
 897         SessionEvent* ev;
 898         boost::shared_ptr<RouteList> r = routes.reader ();
 899
 900         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 901                 if (!(*i)->is_auditioner()) {
 902                         (*i)->silence (nframes);
 903                 }
 904         }
 905
 906         /* run the auditioner, and if it says we need butler service, ask for it */
 907
 908         if (auditioner->play_audition (nframes) > 0) {
 909                 DEBUG_TRACE (DEBUG::Butler, "auditioner needs butler, call it\n");
 910                 _butler->summon ();
 911         }
 912
 913         /* if using a monitor section, run it because otherwise we don't hear anything */
 914
 915         if (_monitor_out && auditioner->needs_monitor()) {
 916                 _monitor_out->monitor_run (_transport_sample, _transport_sample + nframes, nframes, false);
 917         }
 918
 919         /* handle pending events */
 920
 921         while (pending_events.read (&ev, 1) == 1) {
 922                 merge_event (ev);
 923         }
 924
 925         /* if we are not in the middle of a state change,
 926            and there are immediate events queued up,
 927            process them.
 928         */
 929
 930         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 931                 SessionEvent *ev = immediate_events.front ();
 932                 immediate_events.pop_front ();
 933                 process_event (ev);
 934         }
 935
 936         if (!auditioner->auditioning()) {
 937                 /* auditioner no longer active, so go back to the normal process callback */
 938                 process_function = &Session::process_with_events;
 939         }
 940 }
 941
 942 bool
 943 Session::maybe_sync_start (pframes_t & nframes)
 944 {
 945         pframes_t sync_offset;
 946
 947         if (!waiting_for_sync_offset) {
 948                 return false;
 949         }
 950
 951         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 952
 953                 /* generate silence up to the sync point, then
 954                    adjust nframes + offset to reflect whatever
 955                    is left to do.
 956                 */
 957
 958                 no_roll (sync_offset);
 959                 nframes -= sync_offset;
 960                 Port::increment_global_port_buffer_offset (sync_offset);
 961                 waiting_for_sync_offset = false;
 962
 963                 if (nframes == 0) {
 964                         return true; // done, nothing left to process
 965                 }
 966
 967         } else {
 968
 969                 /* sync offset point is not within this process()
 970                    cycle, so just generate silence. and don't bother
 971                    with any fancy stuff here, just the minimal silence.
 972                 */
 973
 974                 _silent = true;
 975
 976                 if (Config->get_locate_while_waiting_for_sync()) {
 977                         if (micro_locate (nframes)) {
 978                                 /* XXX ERROR !!! XXX */
 979                         }
 980                 }
 981
 982                 return true; // done, nothing left to process
 983         }
 984
 985         return false;
 986 }
 987
 988 void
 989 Session::queue_event (SessionEvent* ev)
 990 {
 991         if (_state_of_the_state & Deletion) {
 992                 return;
 993         } else if (_state_of_the_state & Loading) {
 994                 merge_event (ev);
 995         } else {
 996                 Glib::Threads::Mutex::Lock lm (rb_write_lock);
 997                 pending_events.write (&ev, 1);
 998         }
 999 }
1000
1001 void
1002 Session::set_next_event ()
1003 {
1004         if (events.empty()) {
1005                 next_event = events.end();
1006                 return;
1007         }
1008
1009         if (next_event == events.end()) {
1010                 next_event = events.begin();
1011         }
1012
1013         if ((*next_event)->action_sample > _transport_sample) {
1014                 next_event = events.begin();
1015         }
1016
1017         for (; next_event != events.end(); ++next_event) {
1018                 if ((*next_event)->action_sample >= _transport_sample) {
1019                         break;
1020                 }
1021         }
1022 }
1023
1024 void
1025 Session::process_event (SessionEvent* ev)
1026 {
1027         bool remove = true;
1028         bool del = true;
1029
1030         /* if we're in the middle of a state change (i.e. waiting
1031            for the butler thread to complete the non-realtime
1032            part of the change), we'll just have to queue this
1033            event for a time when the change is complete.
1034         */
1035
1036         if (non_realtime_work_pending()) {
1037
1038                 /* except locates, which we have the capability to handle */
1039
1040                 if (ev->type != SessionEvent::Locate) {
1041                         immediate_events.insert (immediate_events.end(), ev);
1042                         _remove_event (ev);
1043                         return;
1044                 }
1045         }
1046
1047         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_sample));
1048
1049         switch (ev->type) {
1050         case SessionEvent::SetLoop:
1051                 set_play_loop (ev->yes_or_no, ev->speed);
1052                 break;
1053
1054         case SessionEvent::AutoLoop:
1055                 if (play_loop) {
1056                         /* roll after locate, do not flush, set "with loop"
1057                            true only if we are seamless looping
1058                         */
1059                         start_locate (ev->target_sample, true, false, Config->get_seamless_loop());
1060                 }
1061                 remove = false;
1062                 del = false;
1063                 break;
1064
1065         case SessionEvent::AutoLoopDeclick:
1066                 if (play_loop) {
1067                         /* Request a declick fade-out and a fade-in; the fade-out will happen
1068                            at the end of the loop, and the fade-in at the start.
1069                         */
1070                         transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
1071                 }
1072                 remove = false;
1073                 del = false;
1074                 break;
1075
1076         case SessionEvent::Locate:
1077                 if (ev->yes_or_no) { /* force locate */
1078                         /* args: do not roll after locate, do flush, not with loop */
1079                         locate (ev->target_sample, false, true, false);
1080                 } else {
1081                         /* args: do not roll after locate, do flush, not with loop */
1082                         start_locate (ev->target_sample, false, true, false);
1083                 }
1084                 _send_timecode_update = true;
1085                 break;
1086
1087         case SessionEvent::LocateRoll:
1088                 if (ev->yes_or_no) {
1089                         /* args: roll after locate, do flush, not with loop */
1090                         locate (ev->target_sample, true, true, false);
1091                 } else {
1092                         /* args: roll after locate, do flush, not with loop */
1093                         start_locate (ev->target_sample, true, true, false);
1094                 }
1095                 _send_timecode_update = true;
1096                 break;
1097
1098         case SessionEvent::Skip:
1099                 if (Config->get_skip_playback()) {
1100                         start_locate (ev->target_sample, true, true, false);
1101                         _send_timecode_update = true;
1102                 }
1103                 remove = false;
1104                 del = false;
1105                 break;
1106
1107         case SessionEvent::LocateRollLocate:
1108                 // locate is handled by ::request_roll_at_and_return()
1109                 _requested_return_sample = ev->target_sample;
1110                 request_locate (ev->target2_sample, true);
1111                 break;
1112
1113
1114         case SessionEvent::SetTransportSpeed:
1115                 set_transport_speed (ev->speed, ev->target_sample, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
1116                 break;
1117
1118         case SessionEvent::PunchIn:
1119                 // cerr << "PunchIN at " << transport_sample() << endl;
1120                 if (config.get_punch_in() && record_status() == Enabled && !preroll_record_punch_enabled()) {
1121                         enable_record ();
1122                 }
1123                 remove = false;
1124                 del = false;
1125                 break;
1126
1127         case SessionEvent::PunchOut:
1128                 // cerr << "PunchOUT at " << transport_sample() << endl;
1129                 if (config.get_punch_out() && !preroll_record_punch_enabled()) {
1130                         step_back_from_record ();
1131                 }
1132                 remove = false;
1133                 del = false;
1134                 break;
1135
1136         case SessionEvent::RecordStart:
1137                 if (preroll_record_punch_enabled() && record_status() == Enabled) {
1138                         enable_record ();
1139                 }
1140                 remove = false;
1141                 del = false;
1142                 break;
1143
1144         case SessionEvent::StopOnce:
1145                 if (!non_realtime_work_pending()) {
1146                         _clear_event_type (SessionEvent::StopOnce);
1147                         stop_transport (ev->yes_or_no);
1148                 }
1149                 remove = false;
1150                 del = false;
1151                 break;
1152
1153         case SessionEvent::RangeStop:
1154                 if (!non_realtime_work_pending()) {
1155                         stop_transport (ev->yes_or_no);
1156                 }
1157                 remove = false;
1158                 del = false;
1159                 break;
1160
1161         case SessionEvent::RangeLocate:
1162                 /* args: roll after locate, do flush, not with loop */
1163                 start_locate (ev->target_sample, true, true, false);
1164                 remove = false;
1165                 del = false;
1166                 break;
1167
1168         case SessionEvent::Overwrite:
1169                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1170                 break;
1171
1172         case SessionEvent::SetSyncSource:
1173                 DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
1174                 use_sync_source (ev->slave);
1175                 break;
1176
1177         case SessionEvent::Audition:
1178                 set_audition (ev->region);
1179                 // drop reference to region
1180                 ev->region.reset ();
1181                 break;
1182
1183         case SessionEvent::SetPlayAudioRange:
1184                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1185                 break;
1186
1187         case SessionEvent::CancelPlayAudioRange:
1188                 unset_play_range();
1189                 break;
1190
1191         case SessionEvent::RealTimeOperation:
1192                 process_rtop (ev);
1193                 del = false; // other side of RT request needs to clean up
1194                 break;
1195
1196         case SessionEvent::AdjustPlaybackBuffering:
1197                 schedule_playback_buffering_adjustment ();
1198                 break;
1199
1200         case SessionEvent::AdjustCaptureBuffering:
1201                 schedule_capture_buffering_adjustment ();
1202                 break;
1203
1204         case SessionEvent::SetTimecodeTransmission:
1205                 g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
1206                 break;
1207
1208         default:
1209           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1210                 abort(); /*NOTREACHED*/
1211                 break;
1212         };
1213
1214         if (remove) {
1215                 del = del && !_remove_event (ev);
1216         }
1217
1218         if (del) {
1219                 delete ev;
1220         }
1221 }
1222
1223 samplepos_t
1224 Session::compute_stop_limit () const
1225 {
1226         if (!Config->get_stop_at_session_end ()) {
1227                 return max_samplepos;
1228         }
1229
1230         if (_slave) {
1231                 return max_samplepos;
1232         }
1233
1234         if (preroll_record_punch_enabled ()) {
1235                 return max_samplepos;
1236         }
1237
1238         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1239         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1240
1241         if (actively_recording ()) {
1242                 /* permanently recording */
1243                 return max_samplepos;
1244         } else if (punching_in && !punching_out) {
1245                 /* punching in but never out */
1246                 return max_samplepos;
1247         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_sample()) {
1248                 /* punching in and punching out after session end */
1249                 return max_samplepos;
1250         }
1251
1252         return current_end_sample ();
1253 }
1254
1255
1256
1257 /* dedicated thread for signal emission.
1258  *
1259  * while sending cross-thread signals from the process thread
1260  * is fine in general, PBD::Signal's use of boost::function and
1261  * boost:bind can produce a vast overhead which is not
1262  * acceptable for low latency.
1263  *
1264  * This works around the issue by moving the boost overhead
1265  * out of the RT thread. The overall load is probably higher but
1266  * the realtime thread remains unaffected.
1267  */
1268
1269 void
1270 Session::emit_route_signals ()
1271 {
1272         // TODO use RAII to allow using these signals in other places
1273         BatchUpdateStart(); /* EMIT SIGNAL */
1274         boost::shared_ptr<RouteList> r = routes.reader ();
1275         for (RouteList::const_iterator ci = r->begin(); ci != r->end(); ++ci) {
1276                 (*ci)->emit_pending_signals ();
1277         }
1278         BatchUpdateEnd(); /* EMIT SIGNAL */
1279 }
1280
1281 void
1282 Session::emit_thread_start ()
1283 {
1284         if (_rt_thread_active) {
1285                 return;
1286         }
1287         _rt_thread_active = true;
1288
1289         if (pthread_create (&_rt_emit_thread, NULL, emit_thread, this)) {
1290                 _rt_thread_active = false;
1291         }
1292 }
1293
1294 void
1295 Session::emit_thread_terminate ()
1296 {
1297         if (!_rt_thread_active) {
1298                 return;
1299         }
1300         _rt_thread_active = false;
1301
1302         if (pthread_mutex_lock (&_rt_emit_mutex) == 0) {
1303                 pthread_cond_signal (&_rt_emit_cond);
1304                 pthread_mutex_unlock (&_rt_emit_mutex);
1305         }
1306
1307         void *status;
1308         pthread_join (_rt_emit_thread, &status);
1309 }
1310
1311 void *
1312 Session::emit_thread (void *arg)
1313 {
1314         Session *s = static_cast<Session *>(arg);
1315         s->emit_thread_run ();
1316         pthread_exit (0);
1317         return 0;
1318 }
1319
1320 void
1321 Session::emit_thread_run ()
1322 {
1323         pthread_mutex_lock (&_rt_emit_mutex);
1324         while (_rt_thread_active) {
1325                 emit_route_signals();
1326                 pthread_cond_wait (&_rt_emit_cond, &_rt_emit_mutex);
1327         }
1328         pthread_mutex_unlock (&_rt_emit_mutex);
1329 }