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         /* only count-in when going to roll at speed 1.0 */
 296         if (_transport_speed != 1.0 && _count_in_samples > 0) {
 297                 _count_in_samples = 0;
 298         }
 299         if (_transport_speed == 0.0) {
 300                 _remaining_latency_preroll = 0;
 301         }
 302
 303         assert (_count_in_samples == 0 || _remaining_latency_preroll == 0 || _count_in_samples == _remaining_latency_preroll);
 304
 305         while (_count_in_samples > 0 || _remaining_latency_preroll > 0) {
 306                 samplecnt_t ns;
 307
 308                 if (_remaining_latency_preroll > 0) {
 309                         ns = std::min ((samplecnt_t)nframes, _remaining_latency_preroll);
 310                 } else {
 311                         ns = std::min ((samplecnt_t)nframes, _count_in_samples);
 312                 }
 313
 314                 boost::shared_ptr<RouteList> r = routes.reader ();
 315                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 316                         samplecnt_t route_offset = (*i)->playback_latency ();
 317                         if (_remaining_latency_preroll > route_offset + ns) {
 318                                 /* route will no-roll for complete pre-roll cycle */
 319                                 continue;
 320                         }
 321                         if (_remaining_latency_preroll > route_offset) {
 322                                 /* route may need partial no-roll and partial roll from
 323                                 * (_transport_sample - _remaining_latency_preroll) ..  +ns.
 324                                 * shorten and split the cycle.
 325                                 */
 326                                 ns = std::min (ns, (_remaining_latency_preroll - route_offset));
 327                         }
 328                 }
 329
 330                 if (_count_in_samples > 0) {
 331                         run_click (_transport_sample - _count_in_samples, ns);
 332                         assert (_count_in_samples >= ns);
 333                         _count_in_samples -= ns;
 334                 }
 335
 336                 if (_remaining_latency_preroll > 0) {
 337                         if (_count_in_samples == 0) {
 338                                 click (_transport_sample - _remaining_latency_preroll, ns);
 339                         }
 340                         if (process_routes (ns, session_needs_butler)) {
 341                                 fail_roll (ns);
 342                         }
 343                 } else {
 344                         no_roll (ns);
 345                 }
 346
 347                 if (_remaining_latency_preroll > 0) {
 348                         assert (_remaining_latency_preroll >= ns);
 349                         _remaining_latency_preroll -= ns;
 350                 }
 351
 352                 nframes -= ns;
 353
 354                 /* process events.. */
 355                 if (!events.empty() && next_event != events.end()) {
 356                         SessionEvent* this_event = *next_event;
 357                         Events::iterator the_next_one = next_event;
 358                         ++the_next_one;
 359
 360                         while (this_event && this_event->action_sample == _transport_sample) {
 361                                 process_event (this_event);
 362                                 if (the_next_one == events.end()) {
 363                                         this_event = 0;
 364                                 } else {
 365                                         this_event = *the_next_one;
 366                                         ++the_next_one;
 367                                 }
 368                         }
 369                         set_next_event ();
 370                 }
 371
 372                 check_declick_out ();
 373
 374                 if (nframes == 0) {
 375                         return;
 376                 } else {
 377                         _engine.split_cycle (ns);
 378                 }
 379         }
 380
 381         /* Decide on what to do with quarter-frame MTC during this cycle */
 382
 383         bool const was_sending_qf_mtc = _send_qf_mtc;
 384         double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
 385
 386         if (_transport_speed != 0) {
 387                 _send_qf_mtc = (
 388                         Config->get_send_mtc () &&
 389                         _transport_speed >= (1 - tolerance) &&
 390                         _transport_speed <= (1 + tolerance)
 391                         );
 392
 393                 if (_send_qf_mtc && !was_sending_qf_mtc) {
 394                         /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
 395                         _send_timecode_update = true;
 396                 }
 397
 398                 if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (sample_rate () / 4)) {
 399                         /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
 400                            a quarter of a second since we sent anything at all, so send a full MTC update
 401                            this cycle.
 402                         */
 403                         _send_timecode_update = true;
 404                 }
 405
 406                 _pframes_since_last_mtc += nframes;
 407         }
 408
 409         /* Events caused a transport change (or we re-started sending
 410          * MTC), so send an MTC Full Frame (Timecode) message.  This
 411          * is sent whether rolling or not, to give slaves an idea of
 412          * ardour time on locates (and allow slow slaves to position
 413          * and prepare for rolling)
 414          */
 415         if (_send_timecode_update) {
 416                 send_full_time_code (_transport_sample, nframes);
 417         }
 418
 419         if (!process_can_proceed()) {
 420                 _silent = true;
 421                 return;
 422         }
 423
 424         if (events.empty() || next_event == events.end()) {
 425                 try_run_lua (nframes); // also during export ?? ->move to process_without_events()
 426                 /* lua scripts may inject events */
 427                 while (_n_lua_scripts > 0 && pending_events.read (&ev, 1) == 1) {
 428                         merge_event (ev);
 429                 }
 430                 if (events.empty() || next_event == events.end()) {
 431                         process_without_events (nframes);
 432                         return;
 433                 }
 434         }
 435
 436         assert (_transport_speed == 0 || _transport_speed == 1.0 || _transport_speed == -1.0);
 437
 438         samples_moved = (samplecnt_t) nframes * _transport_speed;
 439
 440         end_sample = _transport_sample + samples_moved;
 441
 442         {
 443                 SessionEvent* this_event;
 444                 Events::iterator the_next_one;
 445
 446                 if (!process_can_proceed()) {
 447                         _silent = true;
 448                         return;
 449                 }
 450
 451                 if (!_exporting && _slave) {
 452                         if (!follow_slave (nframes)) {
 453                                 return;
 454                         }
 455                 }
 456
 457                 if (_transport_speed == 0) {
 458                         no_roll (nframes);
 459                         return;
 460                 }
 461
 462                 if (!_exporting && !timecode_transmission_suspended()) {
 463                         send_midi_time_code_for_cycle (_transport_sample, end_sample, nframes);
 464                 }
 465
 466                 ltc_tx_send_time_code_for_cycle (_transport_sample, end_sample, _target_transport_speed, _transport_speed, nframes);
 467
 468                 samplepos_t stop_limit = compute_stop_limit ();
 469
 470                 if (maybe_stop (stop_limit)) {
 471                         no_roll (nframes);
 472                         return;
 473                 }
 474
 475                 this_event = *next_event;
 476                 the_next_one = next_event;
 477                 ++the_next_one;
 478
 479                 /* yes folks, here it is, the actual loop where we really truly
 480                    process some audio
 481                 */
 482
 483                 while (nframes) {
 484
 485                         this_nframes = nframes; /* real (jack) time relative */
 486                         samples_moved = (samplecnt_t) floor (_transport_speed * nframes); /* transport relative */
 487
 488                         /* running an event, position transport precisely to its time */
 489                         if (this_event && this_event->action_sample <= end_sample && this_event->action_sample >= _transport_sample) {
 490                                 /* this isn't quite right for reverse play */
 491                                 samples_moved = (samplecnt_t) (this_event->action_sample - _transport_sample);
 492                                 this_nframes = abs (floor(samples_moved / _transport_speed));
 493                         }
 494
 495                         try_run_lua (this_nframes);
 496
 497                         if (this_nframes) {
 498
 499                                 click (_transport_sample, this_nframes);
 500
 501                                 if (process_routes (this_nframes, session_needs_butler)) {
 502                                         fail_roll (nframes);
 503                                         return;
 504                                 }
 505
 506                                 get_track_statistics ();
 507
 508                                 nframes -= this_nframes;
 509
 510                                 if (samples_moved < 0) {
 511                                         decrement_transport_position (-samples_moved);
 512                                 } else if (samples_moved) {
 513                                         increment_transport_position (samples_moved);
 514                                 }
 515
 516                                 maybe_stop (stop_limit);
 517                                 check_declick_out ();
 518                         }
 519
 520                         if (nframes > 0) {
 521                                 _engine.split_cycle (this_nframes);
 522                         }
 523
 524                         /* now handle this event and all others scheduled for the same time */
 525
 526                         while (this_event && this_event->action_sample == _transport_sample) {
 527                                 process_event (this_event);
 528
 529                                 if (the_next_one == events.end()) {
 530                                         this_event = 0;
 531                                 } else {
 532                                         this_event = *the_next_one;
 533                                         ++the_next_one;
 534                                 }
 535                         }
 536
 537                         /* if an event left our state changing, do the right thing */
 538
 539                         if (nframes && non_realtime_work_pending()) {
 540                                 no_roll (nframes);
 541                                 break;
 542                         }
 543
 544                         /* this is necessary to handle the case of seamless looping */
 545                         end_sample = _transport_sample + floor (nframes * _transport_speed);
 546                 }
 547
 548                 set_next_event ();
 549
 550         } /* implicit release of route lock */
 551
 552         if (session_needs_butler) {
 553                 DEBUG_TRACE (DEBUG::Butler, "p-with-events: session needs butler, call it\n");
 554                 _butler->summon ();
 555         }
 556 }
 557
 558 void
 559 Session::reset_slave_state ()
 560 {
 561         average_slave_delta = 1800;
 562         delta_accumulator_cnt = 0;
 563         have_first_delta_accumulator = false;
 564         _slave_state = Stopped;
 565         DiskReader::set_no_disk_output (false);
 566 }
 567
 568 bool
 569 Session::transport_locked () const
 570 {
 571         Slave* sl = _slave;
 572
 573         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 574                 return true;
 575         }
 576
 577         return false;
 578 }
 579
 580 bool
 581 Session::follow_slave (pframes_t nframes)
 582 {
 583         double slave_speed;
 584         samplepos_t slave_transport_sample;
 585         samplecnt_t this_delta;
 586         int dir;
 587
 588         if (!_slave->ok()) {
 589                 stop_transport ();
 590                 config.set_external_sync (false);
 591                 goto noroll;
 592         }
 593
 594         _slave->speed_and_position (slave_speed, slave_transport_sample);
 595
 596         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_sample, slave_speed));
 597
 598         if (!_slave->locked()) {
 599                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 600                 goto noroll;
 601         }
 602
 603         if (slave_transport_sample > _transport_sample) {
 604                 this_delta = slave_transport_sample - _transport_sample;
 605                 dir = 1;
 606         } else {
 607                 this_delta = _transport_sample - slave_transport_sample;
 608                 dir = -1;
 609         }
 610
 611         if (_slave->starting()) {
 612                 slave_speed = 0.0f;
 613         }
 614
 615         if (_slave->is_always_synced() ||
 616                         (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
 617                         ) {
 618
 619                 /* if the TC source is synced, then we assume that its
 620                    speed is binary: 0.0 or 1.0
 621                 */
 622
 623                 if (slave_speed != 0.0f) {
 624                         slave_speed = 1.0f;
 625                 }
 626
 627         } else {
 628
 629                 /* if we are chasing and the average delta between us and the
 630                    master gets too big, we want to switch to silent
 631                    motion. so keep track of that here.
 632                 */
 633
 634                 if (_slave_state == Running) {
 635                         calculate_moving_average_of_slave_delta(dir, abs(this_delta));
 636                 }
 637         }
 638
 639         track_slave_state (slave_speed, slave_transport_sample, this_delta);
 640
 641         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 642                                                    _slave_state, slave_transport_sample, slave_speed, this_delta, average_slave_delta));
 643
 644
 645         if (_slave_state == Running && !_slave->is_always_synced() && !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)) {
 646
 647                 /* may need to varispeed to sync with slave */
 648
 649                 if (_transport_speed != 0.0f) {
 650
 651                         /*
 652                            note that average_dir is +1 or -1
 653                         */
 654
 655                         float delta;
 656
 657                         if (average_slave_delta == 0) {
 658                                 delta = this_delta;
 659                                 delta *= dir;
 660                         } else {
 661                                 delta = average_slave_delta;
 662                                 delta *= average_dir;
 663                         }
 664
 665 #ifndef NDEBUG
 666                         if (slave_speed != 0.0) {
 667                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 668                                                                            (int) (dir * this_delta),
 669                                                                            slave_speed,
 670                                                                            _transport_speed,
 671                                                                            _transport_sample,
 672                                                                            slave_transport_sample,
 673                                                                            average_slave_delta));
 674                         }
 675 #endif
 676
 677                         if (_slave->give_slave_full_control_over_transport_speed()) {
 678                                 set_transport_speed (slave_speed, 0, false, false);
 679                                 //std::cout << "set speed = " << slave_speed << "\n";
 680                         } else {
 681                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_sample_rate)));
 682                                 request_transport_speed (adjusted_speed);
 683                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 684                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 685                                                                            slave_speed));
 686                         }
 687
 688                         if (!actively_recording() && (samplecnt_t) average_slave_delta > _slave->resolution()) {
 689                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("average slave delta %1 greater than slave resolution %2 => no disk output\n", average_slave_delta, _slave->resolution()));
 690                                 /* run routes as normal, but no disk output */
 691                                 DiskReader::set_no_disk_output (true);
 692                                 return true;
 693                         }
 694
 695                         if (!have_first_delta_accumulator) {
 696                                 DEBUG_TRACE (DEBUG::Slave, "waiting for first slave delta accumulator to be ready, no disk output\n");
 697                                 /* run routes as normal, but no disk output */
 698                                 DiskReader::set_no_disk_output (true);
 699                                 return true;
 700                         }
 701                 }
 702         }
 703
 704
 705         if (!have_first_delta_accumulator) {
 706                 DEBUG_TRACE (DEBUG::Slave, "still waiting to compute slave delta, no disk output\n");
 707                 DiskReader::set_no_disk_output (true);
 708         } else {
 709                 DiskReader::set_no_disk_output (false);
 710         }
 711
 712         if ((_slave_state == Running) && (0 == (post_transport_work () & ~PostTransportSpeed))) {
 713                 /* speed is set, we're locked, and good to go */
 714                 return true;
 715         }
 716
 717   noroll:
 718         /* don't move at all */
 719         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 720         no_roll (nframes);
 721         return false;
 722 }
 723
 724 void
 725 Session::calculate_moving_average_of_slave_delta (int dir, samplecnt_t this_delta)
 726 {
 727         if (delta_accumulator_cnt >= delta_accumulator_size) {
 728                 have_first_delta_accumulator = true;
 729                 delta_accumulator_cnt = 0;
 730         }
 731
 732         if (delta_accumulator_cnt != 0 || this_delta < _current_sample_rate) {
 733                 delta_accumulator[delta_accumulator_cnt++] = (samplecnt_t) dir *  (samplecnt_t) this_delta;
 734         }
 735
 736         if (have_first_delta_accumulator) {
 737                 average_slave_delta = 0L;
 738                 for (int i = 0; i < delta_accumulator_size; ++i) {
 739                         average_slave_delta += delta_accumulator[i];
 740                 }
 741                 average_slave_delta /= (int32_t) delta_accumulator_size;
 742                 if (average_slave_delta < 0L) {
 743                         average_dir = -1;
 744                         average_slave_delta = average_slave_delta;
 745                 } else {
 746                         average_dir = 1;
 747                 }
 748         }
 749 }
 750
 751 void
 752 Session::track_slave_state (float slave_speed, samplepos_t slave_transport_sample, samplecnt_t /*this_delta*/)
 753 {
 754         if (slave_speed != 0.0f) {
 755
 756                 /* slave is running */
 757
 758                 switch (_slave_state) {
 759                 case Stopped:
 760                         if (_slave->requires_seekahead()) {
 761                                 slave_wait_end = slave_transport_sample + _slave->seekahead_distance ();
 762                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 763                                 /* we can call locate() here because we are in process context */
 764                                 locate (slave_wait_end, false, false);
 765                                 _slave_state = Waiting;
 766
 767                         } else {
 768
 769                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_sample));
 770
 771                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 772                                 average_slave_delta = 0L;
 773
 774                                 Location* al = _locations->auto_loop_location();
 775
 776                                 if (al && play_loop && (slave_transport_sample < al->start() || slave_transport_sample > al->end())) {
 777                                         // cancel looping
 778                                         request_play_loop(false);
 779                                 }
 780
 781                                 if (slave_transport_sample != _transport_sample) {
 782                                         DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_sample, slave_transport_sample));
 783                                         locate (slave_transport_sample, false, false);
 784                                 }
 785                                 _slave_state = Running;
 786                         }
 787                         break;
 788
 789                 case Waiting:
 790                 default:
 791                         break;
 792                 }
 793
 794                 if (_slave_state == Waiting) {
 795
 796                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_sample));
 797
 798                         if (slave_transport_sample >= slave_wait_end) {
 799
 800                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_sample, _transport_sample));
 801
 802                                 _slave_state = Running;
 803
 804                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 805                                    precisely with the master.
 806                                 */
 807
 808
 809                                 bool ok = true;
 810                                 samplecnt_t sample_delta = slave_transport_sample - _transport_sample;
 811
 812                                 boost::shared_ptr<RouteList> rl = routes.reader();
 813                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 814                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 815                                         if (tr && !tr->can_internal_playback_seek (sample_delta)) {
 816                                                 ok = false;
 817                                                 break;
 818                                         }
 819                                 }
 820
 821                                 if (ok) {
 822                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 823                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 824                                                 if (tr) {
 825                                                         tr->internal_playback_seek (sample_delta);
 826                                                 }
 827                                         }
 828                                         _transport_sample += sample_delta;
 829
 830                                 } else {
 831                                         cerr << "cannot micro-seek\n";
 832                                         /* XXX what? */
 833                                 }
 834                         }
 835                 }
 836
 837                 if (_slave_state == Running && _transport_speed == 0.0f) {
 838                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 839                         start_transport ();
 840                 }
 841
 842         } else { // slave_speed is 0
 843
 844                 /* slave has stopped */
 845
 846                 if (_transport_speed != 0.0f) {
 847                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 sample %2 tf %3\n", slave_speed, slave_transport_sample, _transport_sample));
 848                         stop_transport ();
 849                 }
 850
 851                 if (slave_transport_sample != _transport_sample) {
 852                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_sample));
 853                         force_locate (slave_transport_sample, false);
 854                 }
 855
 856                 reset_slave_state();
 857         }
 858 }
 859
 860 void
 861 Session::process_without_events (pframes_t nframes)
 862 {
 863         bool session_needs_butler = false;
 864         samplecnt_t samples_moved;
 865
 866         if (!process_can_proceed()) {
 867                 _silent = true;
 868                 return;
 869         }
 870
 871         if (!_exporting && _slave) {
 872                 if (!follow_slave (nframes)) {
 873                         ltc_tx_send_time_code_for_cycle (_transport_sample, _transport_sample, 0, 0 , nframes);
 874                         return;
 875                 }
 876         }
 877
 878         if (_transport_speed == 0) {
 879                 no_roll (nframes);
 880                 return;
 881         }
 882
 883         if (_transport_speed == 1.0) {
 884                 samples_moved = (samplecnt_t) nframes;
 885         } else {
 886                 interpolation.set_speed (_transport_speed);
 887                 samples_moved = interpolation.distance (nframes);
 888         }
 889
 890         if (!_exporting && !timecode_transmission_suspended()) {
 891                 send_midi_time_code_for_cycle (_transport_sample, _transport_sample + samples_moved, nframes);
 892         }
 893
 894         ltc_tx_send_time_code_for_cycle (_transport_sample, _transport_sample + samples_moved, _target_transport_speed, _transport_speed, nframes);
 895
 896         samplepos_t const stop_limit = compute_stop_limit ();
 897
 898         if (maybe_stop (stop_limit)) {
 899                 no_roll (nframes);
 900                 return;
 901         }
 902
 903         if (maybe_sync_start (nframes)) {
 904                 return;
 905         }
 906
 907         click (_transport_sample, nframes);
 908
 909         if (process_routes (nframes, session_needs_butler)) {
 910                 fail_roll (nframes);
 911                 return;
 912         }
 913
 914         get_track_statistics ();
 915
 916         if (samples_moved < 0) {
 917                 decrement_transport_position (-samples_moved);
 918         } else if (samples_moved) {
 919                 increment_transport_position (samples_moved);
 920         }
 921
 922         maybe_stop (stop_limit);
 923         check_declick_out ();
 924
 925         if (session_needs_butler) {
 926                 DEBUG_TRACE (DEBUG::Butler, "p-without-events: session needs butler, call it\n");
 927                 _butler->summon ();
 928         }
 929 }
 930
 931 /** Process callback used when the auditioner is active.
 932  * @param nframes number of samples to process.
 933  */
 934 void
 935 Session::process_audition (pframes_t nframes)
 936 {
 937         SessionEvent* ev;
 938         boost::shared_ptr<RouteList> r = routes.reader ();
 939
 940         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 941                 if (!(*i)->is_auditioner()) {
 942                         (*i)->silence (nframes);
 943                 }
 944         }
 945
 946         /* run the auditioner, and if it says we need butler service, ask for it */
 947
 948         if (auditioner->play_audition (nframes) > 0) {
 949                 DEBUG_TRACE (DEBUG::Butler, "auditioner needs butler, call it\n");
 950                 _butler->summon ();
 951         }
 952
 953         /* if using a monitor section, run it because otherwise we don't hear anything */
 954
 955         if (_monitor_out && auditioner->needs_monitor()) {
 956                 _monitor_out->monitor_run (_transport_sample, _transport_sample + nframes, nframes, false);
 957         }
 958
 959         /* handle pending events */
 960
 961         while (pending_events.read (&ev, 1) == 1) {
 962                 merge_event (ev);
 963         }
 964
 965         /* if we are not in the middle of a state change,
 966            and there are immediate events queued up,
 967            process them.
 968         */
 969
 970         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 971                 SessionEvent *ev = immediate_events.front ();
 972                 immediate_events.pop_front ();
 973                 process_event (ev);
 974         }
 975
 976         if (!auditioner->auditioning()) {
 977                 /* auditioner no longer active, so go back to the normal process callback */
 978                 process_function = &Session::process_with_events;
 979         }
 980 }
 981
 982 bool
 983 Session::maybe_sync_start (pframes_t & nframes)
 984 {
 985         pframes_t sync_offset;
 986
 987         if (!waiting_for_sync_offset) {
 988                 return false;
 989         }
 990
 991         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 992
 993                 /* generate silence up to the sync point, then
 994                    adjust nframes + offset to reflect whatever
 995                    is left to do.
 996                 */
 997
 998                 no_roll (sync_offset);
 999                 nframes -= sync_offset;
1000                 Port::increment_global_port_buffer_offset (sync_offset);
1001                 waiting_for_sync_offset = false;
1002
1003                 if (nframes == 0) {
1004                         return true; // done, nothing left to process
1005                 }
1006
1007         } else {
1008
1009                 /* sync offset point is not within this process()
1010                    cycle, so just generate silence. and don't bother
1011                    with any fancy stuff here, just the minimal silence.
1012                 */
1013
1014                 _silent = true;
1015
1016                 if (Config->get_locate_while_waiting_for_sync()) {
1017                         if (micro_locate (nframes)) {
1018                                 /* XXX ERROR !!! XXX */
1019                         }
1020                 }
1021
1022                 return true; // done, nothing left to process
1023         }
1024
1025         return false;
1026 }
1027
1028 void
1029 Session::queue_event (SessionEvent* ev)
1030 {
1031         if (_state_of_the_state & Deletion) {
1032                 return;
1033         } else if (_state_of_the_state & Loading) {
1034                 merge_event (ev);
1035         } else {
1036                 Glib::Threads::Mutex::Lock lm (rb_write_lock);
1037                 pending_events.write (&ev, 1);
1038         }
1039 }
1040
1041 void
1042 Session::set_next_event ()
1043 {
1044         if (events.empty()) {
1045                 next_event = events.end();
1046                 return;
1047         }
1048
1049         if (next_event == events.end()) {
1050                 next_event = events.begin();
1051         }
1052
1053         if ((*next_event)->action_sample > _transport_sample) {
1054                 next_event = events.begin();
1055         }
1056
1057         for (; next_event != events.end(); ++next_event) {
1058                 if ((*next_event)->action_sample >= _transport_sample) {
1059                         break;
1060                 }
1061         }
1062 }
1063
1064 void
1065 Session::process_event (SessionEvent* ev)
1066 {
1067         bool remove = true;
1068         bool del = true;
1069
1070         /* if we're in the middle of a state change (i.e. waiting
1071            for the butler thread to complete the non-realtime
1072            part of the change), we'll just have to queue this
1073            event for a time when the change is complete.
1074         */
1075
1076         if (non_realtime_work_pending()) {
1077
1078                 /* except locates, which we have the capability to handle */
1079
1080                 if (ev->type != SessionEvent::Locate) {
1081                         immediate_events.insert (immediate_events.end(), ev);
1082                         _remove_event (ev);
1083                         return;
1084                 }
1085         }
1086
1087         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_sample));
1088
1089         switch (ev->type) {
1090         case SessionEvent::SetLoop:
1091                 set_play_loop (ev->yes_or_no, ev->speed);
1092                 break;
1093
1094         case SessionEvent::AutoLoop:
1095                 if (play_loop) {
1096                         /* roll after locate, do not flush, set "with loop"
1097                            true only if we are seamless looping
1098                         */
1099                         start_locate (ev->target_sample, true, false, Config->get_seamless_loop());
1100                 }
1101                 remove = false;
1102                 del = false;
1103                 break;
1104
1105         case SessionEvent::AutoLoopDeclick:
1106                 if (play_loop) {
1107                         /* Request a declick fade-out and a fade-in; the fade-out will happen
1108                            at the end of the loop, and the fade-in at the start.
1109                         */
1110                         transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
1111                 }
1112                 remove = false;
1113                 del = false;
1114                 break;
1115
1116         case SessionEvent::Locate:
1117                 if (ev->yes_or_no) { /* force locate */
1118                         /* args: do not roll after locate, do flush, not with loop */
1119                         locate (ev->target_sample, false, true, false);
1120                 } else {
1121                         /* args: do not roll after locate, do flush, not with loop */
1122                         start_locate (ev->target_sample, false, true, false);
1123                 }
1124                 _send_timecode_update = true;
1125                 break;
1126
1127         case SessionEvent::LocateRoll:
1128                 if (ev->yes_or_no) {
1129                         /* args: roll after locate, do flush, not with loop */
1130                         locate (ev->target_sample, true, true, false);
1131                 } else {
1132                         /* args: roll after locate, do flush, not with loop */
1133                         start_locate (ev->target_sample, true, true, false);
1134                 }
1135                 _send_timecode_update = true;
1136                 break;
1137
1138         case SessionEvent::Skip:
1139                 if (Config->get_skip_playback()) {
1140                         start_locate (ev->target_sample, true, true, false);
1141                         _send_timecode_update = true;
1142                 }
1143                 remove = false;
1144                 del = false;
1145                 break;
1146
1147         case SessionEvent::LocateRollLocate:
1148                 // locate is handled by ::request_roll_at_and_return()
1149                 _requested_return_sample = ev->target_sample;
1150                 request_locate (ev->target2_sample, true);
1151                 break;
1152
1153
1154         case SessionEvent::SetTransportSpeed:
1155                 set_transport_speed (ev->speed, ev->target_sample, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
1156                 break;
1157
1158         case SessionEvent::PunchIn:
1159                 // cerr << "PunchIN at " << transport_sample() << endl;
1160                 if (config.get_punch_in() && record_status() == Enabled) {
1161                         enable_record ();
1162                 }
1163                 remove = false;
1164                 del = false;
1165                 break;
1166
1167         case SessionEvent::PunchOut:
1168                 // cerr << "PunchOUT at " << transport_sample() << endl;
1169                 if (config.get_punch_out()) {
1170                         step_back_from_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_sample, 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 samplepos_t
1256 Session::compute_stop_limit () const
1257 {
1258         if (!Config->get_stop_at_session_end ()) {
1259                 return max_samplepos;
1260         }
1261
1262         if (_slave) {
1263                 return max_samplepos;
1264         }
1265
1266         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1267         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1268
1269         if (actively_recording ()) {
1270                 /* permanently recording */
1271                 return max_samplepos;
1272         } else if (punching_in && !punching_out) {
1273                 /* punching in but never out */
1274                 return max_samplepos;
1275         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_sample()) {
1276                 /* punching in and punching out after session end */
1277                 return max_samplepos;
1278         }
1279
1280         return current_end_sample ();
1281 }
1282
1283
1284
1285 /* dedicated thread for signal emission.
1286  *
1287  * while sending cross-thread signals from the process thread
1288  * is fine in general, PBD::Signal's use of boost::function and
1289  * boost:bind can produce a vast overhead which is not
1290  * acceptable for low latency.
1291  *
1292  * This works around the issue by moving the boost overhead
1293  * out of the RT thread. The overall load is probably higher but
1294  * the realtime thread remains unaffected.
1295  */
1296
1297 void
1298 Session::emit_route_signals ()
1299 {
1300         // TODO use RAII to allow using these signals in other places
1301         BatchUpdateStart(); /* EMIT SIGNAL */
1302         boost::shared_ptr<RouteList> r = routes.reader ();
1303         for (RouteList::const_iterator ci = r->begin(); ci != r->end(); ++ci) {
1304                 (*ci)->emit_pending_signals ();
1305         }
1306         BatchUpdateEnd(); /* EMIT SIGNAL */
1307 }
1308
1309 void
1310 Session::emit_thread_start ()
1311 {
1312         if (_rt_thread_active) {
1313                 return;
1314         }
1315         _rt_thread_active = true;
1316
1317         if (pthread_create (&_rt_emit_thread, NULL, emit_thread, this)) {
1318                 _rt_thread_active = false;
1319         }
1320 }
1321
1322 void
1323 Session::emit_thread_terminate ()
1324 {
1325         if (!_rt_thread_active) {
1326                 return;
1327         }
1328         _rt_thread_active = false;
1329
1330         if (pthread_mutex_lock (&_rt_emit_mutex) == 0) {
1331                 pthread_cond_signal (&_rt_emit_cond);
1332                 pthread_mutex_unlock (&_rt_emit_mutex);
1333         }
1334
1335         void *status;
1336         pthread_join (_rt_emit_thread, &status);
1337 }
1338
1339 void *
1340 Session::emit_thread (void *arg)
1341 {
1342         Session *s = static_cast<Session *>(arg);
1343         s->emit_thread_run ();
1344         pthread_exit (0);
1345         return 0;
1346 }
1347
1348 void
1349 Session::emit_thread_run ()
1350 {
1351         pthread_mutex_lock (&_rt_emit_mutex);
1352         while (_rt_thread_active) {
1353                 emit_route_signals();
1354                 pthread_cond_wait (&_rt_emit_cond, &_rt_emit_mutex);
1355         }
1356         pthread_mutex_unlock (&_rt_emit_mutex);
1357 }