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     $Id$
  19 */
  20
  21 #include <cmath>
  22 #include <cerrno>
  23 #include <algorithm>
  24 #include <unistd.h>
  25
  26 #include <ardour/timestamps.h>
  27
  28 #include <pbd/error.h>
  29 #include <pbd/atomic.h>
  30 #include <pbd/lockmonitor.h>
  31
  32 #include <ardour/ardour.h>
  33 #include <ardour/session.h>
  34 #include <ardour/diskstream.h>
  35 #include <ardour/audioengine.h>
  36 #include <ardour/slave.h>
  37 #include <ardour/auditioner.h>
  38 #include <ardour/cycles.h>
  39 #include <ardour/cycle_timer.h>
  40
  41 #include <midi++/manager.h>
  42
  43 #include "i18n.h"
  44
  45 using namespace ARDOUR;
  46 //using namespace sigc;
  47 using namespace std;
  48
  49 void
  50 Session::process (jack_nframes_t nframes)
  51 {
  52         //cerr << "CYCLE START " << _transport_frame << "-------------------" << endl;
  53
  54         MIDI::Manager::instance()->cycle_start(nframes);
  55
  56         if (synced_to_jack() && waiting_to_start) {
  57                 if ( _engine.transport_state() == AudioEngine::TransportRolling) {
  58                         actually_start_transport ();
  59                 }
  60         }
  61
  62         if (non_realtime_work_pending()) {
  63                 if (atomic_read (&butler_should_do_transport_work) == 0) {
  64                         post_transport ();
  65                 }
  66         }
  67
  68         (this->*process_function) (nframes);
  69
  70         MIDI::Manager::instance()->cycle_end();
  71
  72         //cerr << "CYCLE END " << _transport_frame << "-----------------------" << endl;
  73 }
  74
  75 void
  76 Session::prepare_diskstreams ()
  77 {
  78         for (DiskStreamList::iterator i = diskstreams.begin(); i != diskstreams.end(); ++i) {
  79                 (*i)->prepare ();
  80         }
  81 }
  82
  83 int
  84 Session::no_roll (jack_nframes_t nframes, jack_nframes_t offset)
  85 {
  86         jack_nframes_t end_frame = _transport_frame + nframes;
  87         int ret = 0;
  88         bool declick = get_transport_declick_required();
  89
  90         if (_click_io) {
  91                 _click_io->silence (nframes, offset);
  92         }
  93
  94         /* XXX we're supposed to have the route_lock while doing this.
  95            this is really bad ...
  96         */
  97
  98         if (atomic_read (&processing_prohibited)) {
  99                 for (RouteList::iterator i = routes.begin(); i != routes.end(); ++i) {
 100                         (*i)->silence (nframes, offset);
 101                 }
 102                 return 0;
 103         }
 104
 105         for (RouteList::iterator i = routes.begin(); i != routes.end(); ++i) {
 106
 107                 if ((*i)->hidden()) {
 108                         continue;
 109                 }
 110
 111                 (*i)->set_pending_declick (declick);
 112
 113                 if ((*i)->no_roll (nframes, _transport_frame, end_frame, offset, non_realtime_work_pending(),
 114                                    actively_recording(), declick)) {
 115                         error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 116                         ret = -1;
 117                         break;
 118                 }
 119         }
 120
 121         return ret;
 122 }
 123
 124 int
 125 Session::process_routes (jack_nframes_t nframes, jack_nframes_t offset)
 126 {
 127         bool record_active;
 128         int  declick = get_transport_declick_required();
 129         bool rec_monitors = get_rec_monitors_input();
 130
 131         if (transport_sub_state & StopPendingCapture) {
 132                 /* force a declick out */
 133                 declick = -1;
 134         }
 135
 136         record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 137
 138         for (RouteList::iterator i = routes.begin(); i != routes.end(); ++i) {
 139
 140                 int ret;
 141
 142                 if ((*i)->hidden()) {
 143                         continue;
 144                 }
 145
 146                 (*i)->set_pending_declick (declick);
 147
 148                 if ((ret = (*i)->roll (nframes, _transport_frame, _transport_frame + nframes, offset, declick, record_active, rec_monitors)) < 0) {
 149
 150                         /* we have to do this here. Route::roll() for an AudioTrack will have called DiskStream::process(),
 151                            and the DS will expect DiskStream::commit() to be called. but we're aborting from that
 152                            call path, so make sure we release any outstanding locks here before we return failure.
 153                         */
 154
 155                         for (DiskStreamList::iterator ids = diskstreams.begin(); ids != diskstreams.end(); ++ids) {
 156                                 (*ids)->recover ();
 157                         }
 158
 159                         stop_transport ();
 160                         return -1;
 161                 }
 162         }
 163
 164         return 0;
 165 }
 166
 167 int
 168 Session::silent_process_routes (jack_nframes_t nframes, jack_nframes_t offset)
 169 {
 170         bool record_active = actively_recording();
 171         int  declick = get_transport_declick_required();
 172         bool rec_monitors = get_rec_monitors_input();
 173
 174         if (transport_sub_state & StopPendingCapture) {
 175                 /* force a declick out */
 176                 declick = -1;
 177         }
 178
 179         for (RouteList::iterator i = routes.begin(); i != routes.end(); ++i) {
 180
 181                 int ret;
 182
 183                 if ((*i)->hidden()) {
 184                         continue;
 185                 }
 186
 187                 if ((ret = (*i)->silent_roll (nframes, _transport_frame, _transport_frame + nframes, offset, record_active, rec_monitors)) < 0) {
 188
 189                         /* we have to do this here. Route::roll() for an AudioTrack will have called DiskStream::process(),
 190                            and the DS will expect DiskStream::commit() to be called. but we're aborting from that
 191                            call path, so make sure we release any outstanding locks here before we return failure.
 192                         */
 193
 194                         for (DiskStreamList::iterator ids = diskstreams.begin(); ids != diskstreams.end(); ++ids) {
 195                                 (*ids)->recover ();
 196                         }
 197
 198                         stop_transport ();
 199                         return -1;
 200                 }
 201         }
 202
 203         return 0;
 204 }
 205
 206 void
 207 Session::commit_diskstreams (jack_nframes_t nframes, bool &needs_butler)
 208 {
 209         int dret;
 210         float pworst = 1.0f;
 211         float cworst = 1.0f;
 212
 213         for (DiskStreamList::iterator i = diskstreams.begin(); i != diskstreams.end(); ++i) {
 214
 215                 if ((*i)->hidden()) {
 216                         continue;
 217                 }
 218
 219                 /* force all diskstreams not handled by a Route to call do their stuff.
 220                  */
 221
 222                 if ((dret = (*i)->process (_transport_frame, nframes, 0, actively_recording(), get_rec_monitors_input())) == 0) {
 223                         if ((*i)->commit (nframes)) {
 224                                 needs_butler = true;
 225                         }
 226
 227                 } else if (dret < 0) {
 228                         (*i)->recover();
 229                 }
 230
 231                 pworst = min (pworst, (*i)->playback_buffer_load());
 232                 cworst = min (cworst, (*i)->capture_buffer_load());
 233         }
 234
 235         uint32_t pmin = atomic_read (&_playback_load);
 236         uint32_t pminold = atomic_read (&_playback_load_min);
 237         uint32_t cmin = atomic_read (&_capture_load);
 238         uint32_t cminold = atomic_read (&_capture_load_min);
 239
 240         atomic_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 241         atomic_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 242         atomic_set (&_playback_load_min, min (pmin, pminold));
 243         atomic_set (&_capture_load_min, min (cmin, cminold));
 244
 245         if (actively_recording()) {
 246                 set_dirty();
 247         }
 248 }
 249
 250
 251 void
 252 Session::process_with_events (jack_nframes_t nframes)
 253 {
 254         Event*         ev;
 255         jack_nframes_t this_nframes;
 256         jack_nframes_t end_frame;
 257         jack_nframes_t offset;
 258         jack_nframes_t stop_limit;
 259         long           frames_moved;
 260         bool           session_needs_butler = false;
 261
 262         if (auditioner) {
 263                 auditioner->silence (nframes, 0);
 264         }
 265
 266         while (pending_events.read (&ev, 1) == 1) {
 267                 merge_event (ev);
 268         }
 269
 270         /* if we are not in the middle of a state change,
 271            and there are immediate events queued up,
 272            process them.
 273         */
 274
 275         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 276                 Event *ev = immediate_events.front ();
 277                 immediate_events.pop_front ();
 278                 process_event (ev);
 279         }
 280
 281         /* Events caused a transport change and we need to send MTC
 282          * [DR] FIXME: best place for this? */
 283         if (_send_smpte_update) {
 284                 cerr << "[DR] TIME CHANGE\n" << endl;
 285                 send_full_time_code(nframes);
 286         }
 287
 288         if (!process_can_proceed()) {
 289                 no_roll (nframes, 0);
 290                 return;
 291         }
 292
 293         if (events.empty() || next_event == events.end()) {
 294                 process_without_events (nframes);
 295                 return;
 296         }
 297
 298         end_frame = _transport_frame + nframes;
 299
 300         {
 301                 TentativeRWLockMonitor rm (route_lock, false, __LINE__, __FILE__);
 302                 TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 303
 304                 Event* this_event;
 305                 Events::iterator the_next_one;
 306
 307                 if (!rm.locked() || !dsm.locked() || (post_transport_work & (PostTransportLocate|PostTransportStop))) {
 308                         no_roll (nframes, 0);
 309                         return;
 310                 }
 311
 312                 if (!_exporting && _slave) {
 313                         if (!follow_slave (nframes, 0)) {
 314                                 return;
 315                         }
 316                 }
 317
 318                 if (_transport_speed == 0) {
 319                         no_roll (nframes, 0);
 320                         return;
 321                 }
 322
 323                 if (actively_recording()) {
 324                         stop_limit = max_frames;
 325                 } else {
 326
 327                         if (Config->get_stop_at_session_end()) {
 328                                 stop_limit = current_end_frame();
 329                         } else {
 330                                 stop_limit = max_frames;
 331                         }
 332                 }
 333
 334                 if (maybe_stop (stop_limit)) {
 335                         no_roll (nframes, 0);
 336                         return;
 337                 }
 338
 339                 this_event = *next_event;
 340                 the_next_one = next_event;
 341                 ++the_next_one;
 342
 343                 offset = 0;
 344
 345                 while (nframes) {
 346
 347                         if (this_event == 0 || this_event->action_frame > end_frame || this_event->action_frame < _transport_frame) {
 348
 349                                 this_nframes = nframes;
 350
 351                         } else {
 352
 353                                 /* compute nframes to next event */
 354
 355                                 if (this_event->action_frame < end_frame) {
 356                                         this_nframes = nframes - (end_frame - this_event->action_frame);
 357                                 } else {
 358                                         this_nframes = nframes;
 359                                 }
 360                         }
 361
 362                         if (this_nframes) {
 363
 364                                 click (_transport_frame, nframes, offset);
 365
 366                                 /* now process frames between now and the first event in this block */
 367                                 prepare_diskstreams ();
 368
 369                                 if (process_routes (this_nframes, offset)) {
 370                                         no_roll (nframes, 0);
 371                                         return;
 372                                 }
 373
 374                                 commit_diskstreams (this_nframes, session_needs_butler);
 375
 376                                 nframes -= this_nframes;
 377                                 offset += this_nframes;
 378
 379                                 frames_moved = (jack_nframes_t) floor (_transport_speed * this_nframes);
 380
 381                                 if (frames_moved < 0) {
 382                                         decrement_transport_position (-frames_moved);
 383                                 } else {
 384                                         increment_transport_position (frames_moved);
 385                                 }
 386
 387                                 maybe_stop (stop_limit);
 388                                 check_declick_out ();
 389                         }
 390
 391                         /* now handle this event and all others scheduled for the same time */
 392
 393                         while (this_event && this_event->action_frame == _transport_frame) {
 394                                 process_event (this_event);
 395
 396                                 if (the_next_one == events.end()) {
 397                                         this_event = 0;
 398                                 } else {
 399                                         this_event = *the_next_one;
 400                                         ++the_next_one;
 401                                 }
 402                         }
 403
 404                         /* if an event left our state changing, do the right thing */
 405
 406                         if (non_realtime_work_pending()) {
 407                                 no_roll (nframes, offset);
 408                                 break;
 409                         }
 410
 411                         /* this is necessary to handle the case of seamless looping */
 412                         /* not sure if it will work in conjuction with varispeed */
 413                         end_frame = _transport_frame + nframes;
 414
 415                 }
 416
 417                 set_next_event ();
 418
 419         } /* implicit release of route lock */
 420
 421         if (session_needs_butler)
 422                 summon_butler ();
 423
 424         send_midi_time_code_for_cycle(nframes);
 425 }
 426
 427 void
 428 Session::reset_slave_state ()
 429 {
 430         average_slave_delta = 1800;
 431         delta_accumulator_cnt = 0;
 432         have_first_delta_accumulator = false;
 433         slave_state = Stopped;
 434 }
 435
 436 bool
 437 Session::transport_locked () const
 438 {
 439         Slave* sl = _slave;
 440
 441         if (!locate_pending() && ((_slave_type == None) || (sl && sl->ok() && sl->locked()))) {
 442                 return true;
 443         }
 444
 445         return false;
 446 }
 447
 448 bool
 449 Session::follow_slave (jack_nframes_t nframes, jack_nframes_t offset)
 450 {
 451         float slave_speed;
 452         jack_nframes_t slave_transport_frame;
 453         jack_nframes_t this_delta;
 454         int dir;
 455         bool starting;
 456
 457         if (!_slave->ok()) {
 458                 stop_transport ();
 459                 set_slave_source (None, 0);
 460                 goto noroll;
 461         }
 462
 463         _slave->speed_and_position (slave_speed, slave_transport_frame);
 464
 465         if (!_slave->locked()) {
 466                 goto noroll;
 467         }
 468
 469         if (slave_transport_frame > _transport_frame) {
 470                 this_delta = slave_transport_frame - _transport_frame;
 471                 dir = 1;
 472         } else {
 473                 this_delta = _transport_frame - slave_transport_frame;
 474                 dir = -1;
 475         }
 476
 477         if ((starting = _slave->starting())) {
 478                 slave_speed = 0.0f;
 479         }
 480
 481 #if 0
 482         cerr << "delta = " << (int) (dir * this_delta)
 483              << " speed = " << slave_speed
 484              << " ts = " << _transport_speed
 485              << " M@"<< slave_transport_frame << " S@" << _transport_frame
 486              << " avgdelta = " << average_slave_delta
 487              << endl;
 488 #endif
 489
 490         if (Config->get_timecode_source_is_synced()) {
 491
 492                 /* if the TC source is synced, then we assume that its
 493                    speed is binary: 0.0 or 1.0
 494                 */
 495
 496                 if (slave_speed != 0.0f) {
 497                         slave_speed = 1.0f;
 498                 }
 499
 500         } else {
 501
 502                 /* TC source is able to drift relative to us (slave)
 503                    so we need to keep track of the drift and adjust
 504                    our speed to remain locked.
 505                 */
 506
 507                 if (delta_accumulator_cnt >= delta_accumulator_size) {
 508                         have_first_delta_accumulator = true;
 509                         delta_accumulator_cnt = 0;
 510                 }
 511
 512                 if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 513                         delta_accumulator[delta_accumulator_cnt++] = dir*this_delta;
 514                 }
 515
 516                 if (have_first_delta_accumulator) {
 517                         average_slave_delta = 0;
 518                         for (int i = 0; i < delta_accumulator_size; ++i) {
 519                                 average_slave_delta += delta_accumulator[i];
 520                         }
 521                         average_slave_delta /= delta_accumulator_size;
 522                         if (average_slave_delta < 0) {
 523                                 average_dir = -1;
 524                                 average_slave_delta = -average_slave_delta;
 525                         } else {
 526                                 average_dir = 1;
 527                         }
 528                         // cerr << "avgdelta = " << average_slave_delta*average_dir << endl;
 529                 }
 530         }
 531
 532         if (slave_speed != 0.0f) {
 533
 534                 /* slave is running */
 535
 536                 switch (slave_state) {
 537                 case Stopped:
 538                         if (_slave->requires_seekahead()) {
 539                                 slave_wait_end = slave_transport_frame + _current_frame_rate;
 540                                 locate (slave_wait_end, false, false);
 541                                 slave_state = Waiting;
 542                                 starting = true;
 543
 544                         } else {
 545
 546                                 slave_state = Running;
 547
 548                                 Location* al = _locations.auto_loop_location();
 549
 550                                 if (al && auto_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 551                                         // cancel looping
 552                                         request_auto_loop(false);
 553                                 }
 554
 555                                 if (slave_transport_frame != _transport_frame) {
 556                                         locate (slave_transport_frame, false, false);
 557                                 }
 558                         }
 559                         break;
 560
 561                 case Waiting:
 562                         break;
 563
 564                 default:
 565                         break;
 566
 567                 }
 568
 569                 if (slave_state == Waiting) {
 570
 571                         // cerr << "waiting at " << slave_transport_frame << endl;
 572                         TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 573
 574                         if (dsm.locked() && slave_transport_frame >= slave_wait_end) {
 575                                 // cerr << "\tstart at " << _transport_frame << endl;
 576
 577                                 slave_state = Running;
 578
 579                                 bool ok = true;
 580                                 jack_nframes_t frame_delta = slave_transport_frame - _transport_frame;
 581
 582                                 for (DiskStreamList::iterator i = diskstreams.begin(); i != diskstreams.end(); ++i) {
 583                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 584                                                 ok = false;
 585                                                 break;
 586                                         }
 587                                 }
 588
 589                                 if (ok) {
 590                                         for (DiskStreamList::iterator i = diskstreams.begin(); i != diskstreams.end(); ++i) {
 591                                                 (*i)->internal_playback_seek (frame_delta);
 592                                         }
 593                                         _transport_frame += frame_delta;
 594
 595                                 } else {
 596                                         // cerr << "cannot micro-seek\n";
 597                                         /* XXX what? */
 598                                 }
 599
 600                                 memset (delta_accumulator, 0, sizeof (jack_nframes_t) * delta_accumulator_size);
 601                                 average_slave_delta = 0;
 602                                 this_delta = 0;
 603                         }
 604                 }
 605
 606                 if (slave_state == Running && _transport_speed == 0.0f) {
 607
 608                         // cerr << "slave starts transport\n";
 609
 610                         start_transport ();
 611                 }
 612
 613         } else {
 614
 615                 /* slave has stopped */
 616
 617                 if (_transport_speed != 0.0f) {
 618
 619                         // cerr << "slave stops transport: " << slave_speed << " frame: " << slave_transport_frame
 620                         // << " tf = " << _transport_frame
 621                         // << endl;
 622
 623                         if (_slave_type == JACK) {
 624                                 last_stop_frame = _transport_frame;
 625                         }
 626
 627                         stop_transport();
 628                 }
 629
 630                 if (slave_transport_frame != _transport_frame) {
 631                         // cerr << "slave stopped, move to " << slave_transport_frame << endl;
 632                         force_locate (slave_transport_frame, false);
 633                 }
 634
 635                 slave_state = Stopped;
 636         }
 637
 638         if (slave_state == Running && !Config->get_timecode_source_is_synced()) {
 639
 640
 641                 if (_transport_speed != 0.0f) {
 642
 643                         /*
 644                            note that average_dir is +1 or -1
 645                         */
 646
 647                         const float adjust_seconds = 1.0f;
 648                         float delta;
 649
 650                         //if (average_slave_delta == 0) {
 651                                 delta = this_delta;
 652                                 delta *= dir;
 653 //                      } else {
 654 //                              delta = average_slave_delta;
 655 //                              delta *= average_dir;
 656 //                      }
 657
 658                         float adjusted_speed = slave_speed +
 659                                 (delta / (adjust_seconds * _current_frame_rate));
 660
 661                         // cerr << "adjust using " << delta
 662                         // << " towards " << adjusted_speed
 663                         // << " ratio = " << adjusted_speed / slave_speed
 664                         // << " current = " << _transport_speed
 665                         // << " slave @ " << slave_speed
 666                         // << endl;
 667
 668                         request_transport_speed (adjusted_speed);
 669
 670 #if 1
 671                         if ((jack_nframes_t) average_slave_delta > _slave->resolution()) {
 672                                 // cerr << "not locked\n";
 673                                 goto silent_motion;
 674                         }
 675 #endif
 676                 }
 677         }
 678
 679         if (!starting && !non_realtime_work_pending()) {
 680                 /* speed is set, we're locked, and good to go */
 681                 return true;
 682         }
 683
 684   silent_motion:
 685
 686         if (slave_speed && _transport_speed) {
 687
 688                 /* something isn't right, but we should move with the master
 689                    for now.
 690                 */
 691
 692                 bool need_butler;
 693
 694                 TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 695                 if (!dsm.locked()) {
 696                         goto noroll;
 697                 }
 698
 699
 700                 prepare_diskstreams ();
 701                 silent_process_routes (nframes, offset);
 702                 commit_diskstreams (nframes, need_butler);
 703
 704                 if (need_butler) {
 705                         summon_butler ();
 706                 }
 707
 708                 jack_nframes_t frames_moved = (long) floor (_transport_speed * nframes);
 709
 710                 if (frames_moved < 0) {
 711                         decrement_transport_position (-frames_moved);
 712                 } else {
 713                         increment_transport_position (frames_moved);
 714                 }
 715
 716                 jack_nframes_t stop_limit;
 717
 718                 if (actively_recording()) {
 719                         stop_limit = max_frames;
 720                 } else {
 721                         if (Config->get_stop_at_session_end()) {
 722                                 stop_limit = current_end_frame();
 723                         } else {
 724                                 stop_limit = max_frames;
 725                         }
 726                 }
 727
 728                 maybe_stop (stop_limit);
 729         }
 730
 731   noroll:
 732         /* don't move at all */
 733         no_roll (nframes, 0);
 734         return false;
 735 }
 736
 737 void
 738 Session::process_without_events (jack_nframes_t nframes)
 739 {
 740         bool session_needs_butler = false;
 741         jack_nframes_t stop_limit;
 742         long frames_moved;
 743
 744         {
 745                 TentativeRWLockMonitor rm (route_lock, false, __LINE__, __FILE__);
 746                 TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 747
 748                 if (!rm.locked() || !dsm.locked() || (post_transport_work & (PostTransportLocate|PostTransportStop))) {
 749                         no_roll (nframes, 0);
 750                         return;
 751                 }
 752
 753                 if (!_exporting && _slave) {
 754                         if (!follow_slave (nframes, 0)) {
 755                                 return;
 756                         }
 757                 }
 758
 759                 if (_transport_speed == 0) {
 760                         no_roll (nframes, 0);
 761                         return;
 762                 }
 763
 764                 if (actively_recording()) {
 765                         stop_limit = max_frames;
 766                 } else {
 767                         if (Config->get_stop_at_session_end()) {
 768                                 stop_limit = current_end_frame();
 769                         } else {
 770                                 stop_limit = max_frames;
 771                         }
 772                 }
 773
 774                 if (maybe_stop (stop_limit)) {
 775                         no_roll (nframes, 0);
 776                         return;
 777                 }
 778
 779                 click (_transport_frame, nframes, 0);
 780
 781                 prepare_diskstreams ();
 782
 783                 frames_moved = (long) floor (_transport_speed * nframes);
 784
 785                 if (process_routes (nframes, 0)) {
 786                         no_roll (nframes, 0);
 787                         return;
 788                 }
 789
 790                 commit_diskstreams (nframes, session_needs_butler);
 791
 792                 if (frames_moved < 0) {
 793                         decrement_transport_position (-frames_moved);
 794                 } else {
 795                         increment_transport_position (frames_moved);
 796                 }
 797
 798                 maybe_stop (stop_limit);
 799                 check_declick_out ();
 800
 801         } /* implicit release of route lock */
 802
 803         send_midi_time_code_for_cycle(nframes);
 804
 805         if (session_needs_butler)
 806                 summon_butler ();
 807 }
 808
 809 void
 810 Session::process_audition (jack_nframes_t nframes)
 811 {
 812         TentativeRWLockMonitor rm (route_lock, false, __LINE__, __FILE__);
 813         Event* ev;
 814
 815         if (rm.locked()) {
 816                 for (RouteList::iterator i = routes.begin(); i != routes.end(); ++i) {
 817                         if (!(*i)->hidden()) {
 818                                 (*i)->silence (nframes, 0);
 819                         }
 820                 }
 821         }
 822
 823         if (auditioner->play_audition (nframes) > 0) {
 824                 summon_butler ();
 825         }
 826
 827         while (pending_events.read (&ev, 1) == 1) {
 828                 merge_event (ev);
 829         }
 830
 831         /* if we are not in the middle of a state change,
 832            and there are immediate events queued up,
 833            process them.
 834         */
 835
 836         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 837                 Event *ev = immediate_events.front ();
 838                 immediate_events.pop_front ();
 839                 process_event (ev);
 840         }
 841
 842         if (!auditioner->active()) {
 843                 process_function = &Session::process_with_events;
 844         }
 845 }
 846