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, send an MTC Full Frame (SMPTE) message.
 282          * This is sent whether rolling or not, to give slaves an idea of ardour time
 283          * on locates (and allow slow slaves to position and prepare for rolling)
 284          */
 285         if (_send_smpte_update) {
 286                 send_full_time_code(nframes);
 287         }
 288
 289         if (!process_can_proceed()) {
 290                 no_roll (nframes, 0);
 291                 return;
 292         }
 293
 294         if (events.empty() || next_event == events.end()) {
 295                 process_without_events (nframes);
 296                 return;
 297         }
 298
 299         end_frame = _transport_frame + nframes;
 300
 301         {
 302                 TentativeRWLockMonitor rm (route_lock, false, __LINE__, __FILE__);
 303                 TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 304
 305                 Event* this_event;
 306                 Events::iterator the_next_one;
 307
 308                 if (!rm.locked() || !dsm.locked() || (post_transport_work & (PostTransportLocate|PostTransportStop))) {
 309                         no_roll (nframes, 0);
 310                         return;
 311                 }
 312
 313                 if (!_exporting && _slave) {
 314                         if (!follow_slave (nframes, 0)) {
 315                                 return;
 316                         }
 317                 }
 318
 319                 if (_transport_speed == 0) {
 320                         no_roll (nframes, 0);
 321                         return;
 322                 }
 323
 324                 send_midi_time_code_for_cycle(nframes);
 325
 326                 if (actively_recording()) {
 327                         stop_limit = max_frames;
 328                 } else {
 329
 330                         if (Config->get_stop_at_session_end()) {
 331                                 stop_limit = current_end_frame();
 332                         } else {
 333                                 stop_limit = max_frames;
 334                         }
 335                 }
 336
 337                 if (maybe_stop (stop_limit)) {
 338                         no_roll (nframes, 0);
 339                         return;
 340                 }
 341
 342                 this_event = *next_event;
 343                 the_next_one = next_event;
 344                 ++the_next_one;
 345
 346                 offset = 0;
 347
 348                 while (nframes) {
 349
 350                         if (this_event == 0 || this_event->action_frame > end_frame || this_event->action_frame < _transport_frame) {
 351
 352                                 this_nframes = nframes;
 353
 354                         } else {
 355
 356                                 /* compute nframes to next event */
 357
 358                                 if (this_event->action_frame < end_frame) {
 359                                         this_nframes = nframes - (end_frame - this_event->action_frame);
 360                                 } else {
 361                                         this_nframes = nframes;
 362                                 }
 363                         }
 364
 365                         if (this_nframes) {
 366
 367                                 click (_transport_frame, nframes, offset);
 368
 369                                 /* now process frames between now and the first event in this block */
 370                                 prepare_diskstreams ();
 371
 372                                 if (process_routes (this_nframes, offset)) {
 373                                         no_roll (nframes, 0);
 374                                         return;
 375                                 }
 376
 377                                 commit_diskstreams (this_nframes, session_needs_butler);
 378
 379                                 nframes -= this_nframes;
 380                                 offset += this_nframes;
 381
 382                                 frames_moved = (jack_nframes_t) floor (_transport_speed * this_nframes);
 383
 384                                 if (frames_moved < 0) {
 385                                         decrement_transport_position (-frames_moved);
 386                                 } else {
 387                                         increment_transport_position (frames_moved);
 388                                 }
 389
 390                                 maybe_stop (stop_limit);
 391                                 check_declick_out ();
 392                         }
 393
 394                         /* now handle this event and all others scheduled for the same time */
 395
 396                         while (this_event && this_event->action_frame == _transport_frame) {
 397                                 process_event (this_event);
 398
 399                                 if (the_next_one == events.end()) {
 400                                         this_event = 0;
 401                                 } else {
 402                                         this_event = *the_next_one;
 403                                         ++the_next_one;
 404                                 }
 405                         }
 406
 407                         /* if an event left our state changing, do the right thing */
 408
 409                         if (non_realtime_work_pending()) {
 410                                 no_roll (nframes, offset);
 411                                 break;
 412                         }
 413
 414                         /* this is necessary to handle the case of seamless looping */
 415                         /* not sure if it will work in conjuction with varispeed */
 416                         end_frame = _transport_frame + nframes;
 417
 418                 }
 419
 420                 set_next_event ();
 421
 422         } /* implicit release of route lock */
 423
 424         if (session_needs_butler)
 425                 summon_butler ();
 426 }
 427
 428 void
 429 Session::reset_slave_state ()
 430 {
 431         average_slave_delta = 1800;
 432         delta_accumulator_cnt = 0;
 433         have_first_delta_accumulator = false;
 434         slave_state = Stopped;
 435 }
 436
 437 bool
 438 Session::transport_locked () const
 439 {
 440         Slave* sl = _slave;
 441
 442         if (!locate_pending() && ((_slave_type == None) || (sl && sl->ok() && sl->locked()))) {
 443                 return true;
 444         }
 445
 446         return false;
 447 }
 448
 449 bool
 450 Session::follow_slave (jack_nframes_t nframes, jack_nframes_t offset)
 451 {
 452         float slave_speed;
 453         jack_nframes_t slave_transport_frame;
 454         jack_nframes_t this_delta;
 455         int dir;
 456         bool starting;
 457
 458         if (!_slave->ok()) {
 459                 stop_transport ();
 460                 set_slave_source (None, 0);
 461                 goto noroll;
 462         }
 463
 464         _slave->speed_and_position (slave_speed, slave_transport_frame);
 465
 466         if (!_slave->locked()) {
 467                 goto noroll;
 468         }
 469
 470         if (slave_transport_frame > _transport_frame) {
 471                 this_delta = slave_transport_frame - _transport_frame;
 472                 dir = 1;
 473         } else {
 474                 this_delta = _transport_frame - slave_transport_frame;
 475                 dir = -1;
 476         }
 477
 478         if ((starting = _slave->starting())) {
 479                 slave_speed = 0.0f;
 480         }
 481
 482 #if 0
 483         cerr << "delta = " << (int) (dir * this_delta)
 484              << " speed = " << slave_speed
 485              << " ts = " << _transport_speed
 486              << " M@"<< slave_transport_frame << " S@" << _transport_frame
 487              << " avgdelta = " << average_slave_delta
 488              << endl;
 489 #endif
 490
 491         if (Config->get_timecode_source_is_synced()) {
 492
 493                 /* if the TC source is synced, then we assume that its
 494                    speed is binary: 0.0 or 1.0
 495                 */
 496
 497                 if (slave_speed != 0.0f) {
 498                         slave_speed = 1.0f;
 499                 }
 500
 501         } else {
 502
 503                 /* TC source is able to drift relative to us (slave)
 504                    so we need to keep track of the drift and adjust
 505                    our speed to remain locked.
 506                 */
 507
 508                 if (delta_accumulator_cnt >= delta_accumulator_size) {
 509                         have_first_delta_accumulator = true;
 510                         delta_accumulator_cnt = 0;
 511                 }
 512
 513                 if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 514                         delta_accumulator[delta_accumulator_cnt++] = dir*this_delta;
 515                 }
 516
 517                 if (have_first_delta_accumulator) {
 518                         average_slave_delta = 0;
 519                         for (int i = 0; i < delta_accumulator_size; ++i) {
 520                                 average_slave_delta += delta_accumulator[i];
 521                         }
 522                         average_slave_delta /= delta_accumulator_size;
 523                         if (average_slave_delta < 0) {
 524                                 average_dir = -1;
 525                                 average_slave_delta = -average_slave_delta;
 526                         } else {
 527                                 average_dir = 1;
 528                         }
 529                         // cerr << "avgdelta = " << average_slave_delta*average_dir << endl;
 530                 }
 531         }
 532
 533         if (slave_speed != 0.0f) {
 534
 535                 /* slave is running */
 536
 537                 switch (slave_state) {
 538                 case Stopped:
 539                         if (_slave->requires_seekahead()) {
 540                                 slave_wait_end = slave_transport_frame + _current_frame_rate;
 541                                 locate (slave_wait_end, false, false);
 542                                 slave_state = Waiting;
 543                                 starting = true;
 544
 545                         } else {
 546
 547                                 slave_state = Running;
 548
 549                                 Location* al = _locations.auto_loop_location();
 550
 551                                 if (al && auto_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 552                                         // cancel looping
 553                                         request_auto_loop(false);
 554                                 }
 555
 556                                 if (slave_transport_frame != _transport_frame) {
 557                                         locate (slave_transport_frame, false, false);
 558                                 }
 559                         }
 560                         break;
 561
 562                 case Waiting:
 563                         break;
 564
 565                 default:
 566                         break;
 567
 568                 }
 569
 570                 if (slave_state == Waiting) {
 571
 572                         // cerr << "waiting at " << slave_transport_frame << endl;
 573                         TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 574
 575                         if (dsm.locked() && slave_transport_frame >= slave_wait_end) {
 576                                 // cerr << "\tstart at " << _transport_frame << endl;
 577
 578                                 slave_state = Running;
 579
 580                                 bool ok = true;
 581                                 jack_nframes_t frame_delta = slave_transport_frame - _transport_frame;
 582
 583                                 for (DiskStreamList::iterator i = diskstreams.begin(); i != diskstreams.end(); ++i) {
 584                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 585                                                 ok = false;
 586                                                 break;
 587                                         }
 588                                 }
 589
 590                                 if (ok) {
 591                                         for (DiskStreamList::iterator i = diskstreams.begin(); i != diskstreams.end(); ++i) {
 592                                                 (*i)->internal_playback_seek (frame_delta);
 593                                         }
 594                                         _transport_frame += frame_delta;
 595
 596                                 } else {
 597                                         // cerr << "cannot micro-seek\n";
 598                                         /* XXX what? */
 599                                 }
 600
 601                                 memset (delta_accumulator, 0, sizeof (jack_nframes_t) * delta_accumulator_size);
 602                                 average_slave_delta = 0;
 603                                 this_delta = 0;
 604                         }
 605                 }
 606
 607                 if (slave_state == Running && _transport_speed == 0.0f) {
 608
 609                         // cerr << "slave starts transport\n";
 610
 611                         start_transport ();
 612                 }
 613
 614         } else {
 615
 616                 /* slave has stopped */
 617
 618                 if (_transport_speed != 0.0f) {
 619
 620                         // cerr << "slave stops transport: " << slave_speed << " frame: " << slave_transport_frame
 621                         // << " tf = " << _transport_frame
 622                         // << endl;
 623
 624                         if (_slave_type == JACK) {
 625                                 last_stop_frame = _transport_frame;
 626                         }
 627
 628                         stop_transport();
 629                 }
 630
 631                 if (slave_transport_frame != _transport_frame) {
 632                         // cerr << "slave stopped, move to " << slave_transport_frame << endl;
 633                         force_locate (slave_transport_frame, false);
 634                 }
 635
 636                 slave_state = Stopped;
 637         }
 638
 639         if (slave_state == Running && !Config->get_timecode_source_is_synced()) {
 640
 641
 642                 if (_transport_speed != 0.0f) {
 643
 644                         /*
 645                            note that average_dir is +1 or -1
 646                         */
 647
 648                         const float adjust_seconds = 1.0f;
 649                         float delta;
 650
 651                         //if (average_slave_delta == 0) {
 652                                 delta = this_delta;
 653                                 delta *= dir;
 654 //                      } else {
 655 //                              delta = average_slave_delta;
 656 //                              delta *= average_dir;
 657 //                      }
 658
 659                         float adjusted_speed = slave_speed +
 660                                 (delta / (adjust_seconds * _current_frame_rate));
 661
 662                         // cerr << "adjust using " << delta
 663                         // << " towards " << adjusted_speed
 664                         // << " ratio = " << adjusted_speed / slave_speed
 665                         // << " current = " << _transport_speed
 666                         // << " slave @ " << slave_speed
 667                         // << endl;
 668
 669                         request_transport_speed (adjusted_speed);
 670
 671 #if 1
 672                         if ((jack_nframes_t) average_slave_delta > _slave->resolution()) {
 673                                 // cerr << "not locked\n";
 674                                 goto silent_motion;
 675                         }
 676 #endif
 677                 }
 678         }
 679
 680         if (!starting && !non_realtime_work_pending()) {
 681                 /* speed is set, we're locked, and good to go */
 682                 return true;
 683         }
 684
 685   silent_motion:
 686
 687         if (slave_speed && _transport_speed) {
 688
 689                 /* something isn't right, but we should move with the master
 690                    for now.
 691                 */
 692
 693                 bool need_butler;
 694
 695                 TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 696                 if (!dsm.locked()) {
 697                         goto noroll;
 698                 }
 699
 700
 701                 prepare_diskstreams ();
 702                 silent_process_routes (nframes, offset);
 703                 commit_diskstreams (nframes, need_butler);
 704
 705                 if (need_butler) {
 706                         summon_butler ();
 707                 }
 708
 709                 jack_nframes_t frames_moved = (long) floor (_transport_speed * nframes);
 710
 711                 if (frames_moved < 0) {
 712                         decrement_transport_position (-frames_moved);
 713                 } else {
 714                         increment_transport_position (frames_moved);
 715                 }
 716
 717                 jack_nframes_t stop_limit;
 718
 719                 if (actively_recording()) {
 720                         stop_limit = max_frames;
 721                 } else {
 722                         if (Config->get_stop_at_session_end()) {
 723                                 stop_limit = current_end_frame();
 724                         } else {
 725                                 stop_limit = max_frames;
 726                         }
 727                 }
 728
 729                 maybe_stop (stop_limit);
 730         }
 731
 732   noroll:
 733         /* don't move at all */
 734         no_roll (nframes, 0);
 735         return false;
 736 }
 737
 738 void
 739 Session::process_without_events (jack_nframes_t nframes)
 740 {
 741         bool session_needs_butler = false;
 742         jack_nframes_t stop_limit;
 743         long frames_moved;
 744
 745         {
 746                 TentativeRWLockMonitor rm (route_lock, false, __LINE__, __FILE__);
 747                 TentativeRWLockMonitor dsm (diskstream_lock, false, __LINE__, __FILE__);
 748
 749                 if (!rm.locked() || !dsm.locked() || (post_transport_work & (PostTransportLocate|PostTransportStop))) {
 750                         no_roll (nframes, 0);
 751                         return;
 752                 }
 753
 754                 if (!_exporting && _slave) {
 755                         if (!follow_slave (nframes, 0)) {
 756                                 return;
 757                         }
 758                 }
 759
 760                 if (_transport_speed == 0) {
 761                         no_roll (nframes, 0);
 762                         return;
 763                 }
 764
 765                 send_midi_time_code_for_cycle(nframes);
 766
 767                 if (actively_recording()) {
 768                         stop_limit = max_frames;
 769                 } else {
 770                         if (Config->get_stop_at_session_end()) {
 771                                 stop_limit = current_end_frame();
 772                         } else {
 773                                 stop_limit = max_frames;
 774                         }
 775                 }
 776
 777                 if (maybe_stop (stop_limit)) {
 778                         no_roll (nframes, 0);
 779                         return;
 780                 }
 781
 782                 click (_transport_frame, nframes, 0);
 783
 784                 prepare_diskstreams ();
 785
 786                 frames_moved = (long) floor (_transport_speed * nframes);
 787
 788                 if (process_routes (nframes, 0)) {
 789                         no_roll (nframes, 0);
 790                         return;
 791                 }
 792
 793                 commit_diskstreams (nframes, session_needs_butler);
 794
 795                 if (frames_moved < 0) {
 796                         decrement_transport_position (-frames_moved);
 797                 } else {
 798                         increment_transport_position (frames_moved);
 799                 }
 800
 801                 maybe_stop (stop_limit);
 802                 check_declick_out ();
 803
 804         } /* implicit release of route lock */
 805
 806         if (session_needs_butler)
 807                 summon_butler ();
 808 }
 809
 810 void
 811 Session::process_audition (jack_nframes_t nframes)
 812 {
 813         TentativeRWLockMonitor rm (route_lock, false, __LINE__, __FILE__);
 814         Event* ev;
 815
 816         if (rm.locked()) {
 817                 for (RouteList::iterator i = routes.begin(); i != routes.end(); ++i) {
 818                         if (!(*i)->hidden()) {
 819                                 (*i)->silence (nframes, 0);
 820                         }
 821                 }
 822         }
 823
 824         if (auditioner->play_audition (nframes) > 0) {
 825                 summon_butler ();
 826         }
 827
 828         while (pending_events.read (&ev, 1) == 1) {
 829                 merge_event (ev);
 830         }
 831
 832         /* if we are not in the middle of a state change,
 833            and there are immediate events queued up,
 834            process them.
 835         */
 836
 837         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 838                 Event *ev = immediate_events.front ();
 839                 immediate_events.pop_front ();
 840                 process_event (ev);
 841         }
 842
 843         if (!auditioner->active()) {
 844                 process_function = &Session::process_with_events;
 845         }
 846 }
 847