libs/ardour/butler.cc

   1 /*
   2     Copyright (C) 1999-2009 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 <errno.h>
  21 #include <fcntl.h>
  22 #include <unistd.h>
  23 #include <poll.h>
  24 #include "pbd/error.h"
  25 #include "pbd/pthread_utils.h"
  26 #include "ardour/butler.h"
  27 #include "ardour/crossfade.h"
  28 #include "ardour/io.h"
  29 #include "ardour/midi_diskstream.h"
  30 #include "ardour/session.h"
  31 #include "ardour/track.h"
  32 #include "ardour/auditioner.h"
  33
  34 #include "i18n.h"
  35
  36 using namespace PBD;
  37
  38 static float _read_data_rate;
  39 static float _write_data_rate;
  40
  41 namespace ARDOUR {
  42
  43 Butler::Butler(Session& s)
  44         : SessionHandleRef (s)
  45         , thread(0)
  46         , audio_dstream_capture_buffer_size(0)
  47         , audio_dstream_playback_buffer_size(0)
  48         , midi_dstream_buffer_size(0)
  49         , pool_trash(16)
  50 {
  51         g_atomic_int_set(&should_do_transport_work, 0);
  52         SessionEvent::pool->set_trash (&pool_trash);
  53
  54         Config->ParameterChanged.connect_same_thread (*this, boost::bind (&Butler::config_changed, this, _1));
  55 }
  56
  57 Butler::~Butler()
  58 {
  59         terminate_thread ();
  60 }
  61
  62 void
  63 Butler::config_changed (std::string p)
  64 {
  65         if (p == "playback-buffer-seconds") {
  66                 /* size is in Samples, not bytes */
  67                 audio_dstream_playback_buffer_size = (uint32_t) floor (Config->get_audio_playback_buffer_seconds() * _session.frame_rate());
  68                 _session.adjust_playback_buffering ();
  69         } else if (p == "capture-buffer-seconds") {
  70                 audio_dstream_capture_buffer_size = (uint32_t) floor (Config->get_audio_capture_buffer_seconds() * _session.frame_rate());
  71                 _session.adjust_capture_buffering ();
  72         }
  73 }
  74
  75 int
  76 Butler::start_thread()
  77 {
  78         const float rate = (float)_session.frame_rate();
  79
  80         /* size is in Samples, not bytes */
  81         audio_dstream_capture_buffer_size = (uint32_t) floor (Config->get_audio_capture_buffer_seconds() * rate);
  82         audio_dstream_playback_buffer_size = (uint32_t) floor (Config->get_audio_playback_buffer_seconds() * rate);
  83
  84         /* size is in bytes
  85          * XXX: Jack needs to tell us the MIDI buffer size
  86          * (i.e. how many MIDI bytes we might see in a cycle)
  87          */
  88         midi_dstream_buffer_size = (uint32_t) floor (Config->get_midi_track_buffer_seconds() * rate);
  89
  90         MidiDiskstream::set_readahead_frames ((framecnt_t) (Config->get_midi_readahead() * rate));
  91
  92         Crossfade::set_buffer_size (audio_dstream_playback_buffer_size);
  93
  94         should_run = false;
  95
  96         if (pipe (request_pipe)) {
  97                 error << string_compose(_("Cannot create transport request signal pipe (%1)"),
  98                                 strerror (errno)) << endmsg;
  99                 return -1;
 100         }
 101
 102         if (fcntl (request_pipe[0], F_SETFL, O_NONBLOCK)) {
 103                 error << string_compose(_("UI: cannot set O_NONBLOCK on butler request pipe (%1)"),
 104                                 strerror (errno)) << endmsg;
 105                 return -1;
 106         }
 107
 108         if (fcntl (request_pipe[1], F_SETFL, O_NONBLOCK)) {
 109                 error << string_compose(_("UI: cannot set O_NONBLOCK on butler request pipe (%1)"),
 110                                 strerror (errno)) << endmsg;
 111                 return -1;
 112         }
 113
 114         if (pthread_create_and_store ("disk butler", &thread, _thread_work, this)) {
 115                 error << _("Session: could not create butler thread") << endmsg;
 116                 return -1;
 117         }
 118
 119         //pthread_detach (thread);
 120
 121         return 0;
 122 }
 123
 124 void
 125 Butler::terminate_thread ()
 126 {
 127         if (thread) {
 128                 void* status;
 129                 const char c = Request::Quit;
 130                 (void) ::write (request_pipe[1], &c, 1);
 131                 pthread_join (thread, &status);
 132         }
 133 }
 134
 135 void *
 136 Butler::_thread_work (void* arg)
 137 {
 138         SessionEvent::create_per_thread_pool ("butler events", 64);
 139         pthread_set_name (X_("butler"));
 140         return ((Butler *) arg)->thread_work ();
 141 }
 142
 143 void *
 144 Butler::thread_work ()
 145 {
 146         uint32_t err = 0;
 147         int32_t bytes;
 148         bool compute_io;
 149         microseconds_t begin, end;
 150
 151         struct pollfd pfd[1];
 152         bool disk_work_outstanding = false;
 153         RouteList::iterator i;
 154
 155         while (true) {
 156                 pfd[0].fd = request_pipe[0];
 157                 pfd[0].events = POLLIN|POLLERR|POLLHUP;
 158
 159                 if (poll (pfd, 1, (disk_work_outstanding ? 0 : -1)) < 0) {
 160
 161                         if (errno == EINTR) {
 162                                 continue;
 163                         }
 164
 165                         error << string_compose (_("poll on butler request pipe failed (%1)"),
 166                                           strerror (errno))
 167                               << endmsg;
 168                         break;
 169                 }
 170
 171                 if (pfd[0].revents & ~POLLIN) {
 172                         error << string_compose (_("Error on butler thread request pipe: fd=%1 err=%2"), pfd[0].fd, pfd[0].revents) << endmsg;
 173                         break;
 174                 }
 175
 176                 if (pfd[0].revents & POLLIN) {
 177
 178                         char req;
 179
 180                         /* empty the pipe of all current requests */
 181
 182                         while (1) {
 183                                 size_t nread = ::read (request_pipe[0], &req, sizeof (req));
 184                                 if (nread == 1) {
 185
 186                                         switch ((Request::Type) req) {
 187
 188                                         case Request::Wake:
 189                                                 break;
 190
 191                                         case Request::Run:
 192                                                 should_run = true;
 193                                                 break;
 194
 195                                         case Request::Pause:
 196                                                 should_run = false;
 197                                                 break;
 198
 199                                         case Request::Quit:
 200                                                 pthread_exit_pbd (0);
 201                                                 /*NOTREACHED*/
 202                                                 break;
 203
 204                                         default:
 205                                                 break;
 206                                         }
 207
 208                                 } else if (nread == 0) {
 209                                         break;
 210                                 } else if (errno == EAGAIN) {
 211                                         break;
 212                                 } else {
 213                                         fatal << _("Error reading from butler request pipe") << endmsg;
 214                                         /*NOTREACHED*/
 215                                 }
 216                         }
 217                 }
 218
 219
 220                 bytes = 0;
 221                 compute_io = true;
 222
 223 restart:
 224                 disk_work_outstanding = false;
 225
 226                 if (transport_work_requested()) {
 227                         _session.butler_transport_work ();
 228                 }
 229
 230                 begin = get_microseconds();
 231
 232                 boost::shared_ptr<RouteList> rl = _session.get_routes();
 233
 234                 RouteList rl_with_auditioner = *rl;
 235                 rl_with_auditioner.push_back (_session.the_auditioner());
 236
 237 //              for (i = dsl->begin(); i != dsl->end(); ++i) {
 238 //                      cerr << "BEFORE " << (*i)->name() << ": pb = " << (*i)->playback_buffer_load() << " cp = " << (*i)->capture_buffer_load() << endl;
 239 //              }
 240
 241                 for (i = rl_with_auditioner.begin(); !transport_work_requested() && should_run && i != rl_with_auditioner.end(); ++i) {
 242
 243                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 244                         if (!tr) {
 245                                 continue;
 246                         }
 247
 248                         /* don't read inactive tracks */
 249
 250                         boost::shared_ptr<IO> io = tr->input ();
 251
 252                         if (io && !io->active()) {
 253                                 continue;
 254                         }
 255
 256                         switch (tr->do_refill ()) {
 257                         case 0:
 258                                 bytes += tr->read_data_count();
 259                                 break;
 260                         case 1:
 261                                 bytes += tr->read_data_count();
 262                                 disk_work_outstanding = true;
 263                                 break;
 264
 265                         default:
 266                                 compute_io = false;
 267                                 error << string_compose(_("Butler read ahead failure on dstream %1"), (*i)->name()) << endmsg;
 268                                 break;
 269                         }
 270
 271                 }
 272
 273                 if (i != rl_with_auditioner.begin() && i != rl_with_auditioner.end()) {
 274                         /* we didn't get to all the streams */
 275                         disk_work_outstanding = true;
 276                 }
 277
 278                 if (!err && transport_work_requested()) {
 279                         goto restart;
 280                 }
 281
 282                 if (compute_io) {
 283                         end = get_microseconds();
 284                         if (end - begin > 0) {
 285                                 _read_data_rate = (float) bytes / (float) (end - begin);
 286                         } else {
 287                                 _read_data_rate = 0; // infinity better
 288                         }
 289                 }
 290
 291                 bytes = 0;
 292                 compute_io = true;
 293                 begin = get_microseconds();
 294
 295                 for (i = rl->begin(); !transport_work_requested() && should_run && i != rl->end(); ++i) {
 296                         // cerr << "write behind for " << (*i)->name () << endl;
 297
 298                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 299                         if (!tr) {
 300                                 continue;
 301                         }
 302
 303                         /* note that we still try to flush diskstreams attached to inactive routes
 304                          */
 305
 306                         switch (tr->do_flush (ButlerContext)) {
 307                         case 0:
 308                                 bytes += tr->write_data_count();
 309                                 break;
 310                         case 1:
 311                                 bytes += tr->write_data_count();
 312                                 disk_work_outstanding = true;
 313                                 break;
 314
 315                         default:
 316                                 err++;
 317                                 compute_io = false;
 318                                 error << string_compose(_("Butler write-behind failure on dstream %1"), (*i)->name()) << endmsg;
 319                                 /* don't break - try to flush all streams in case they
 320                                    are split across disks.
 321                                 */
 322                         }
 323                 }
 324
 325                 if (err && _session.actively_recording()) {
 326                         /* stop the transport and try to catch as much possible
 327                            captured state as we can.
 328                         */
 329                         _session.request_stop ();
 330                 }
 331
 332                 if (i != rl->begin() && i != rl->end()) {
 333                         /* we didn't get to all the streams */
 334                         disk_work_outstanding = true;
 335                 }
 336
 337                 if (!err && transport_work_requested()) {
 338                         goto restart;
 339                 }
 340
 341                 if (compute_io) {
 342                         // there are no apparent users for this calculation?
 343                         end = get_microseconds();
 344                         if (end - begin > 0) {
 345                                 _write_data_rate = (float) bytes / (float) (end - begin);
 346                         } else {
 347                                 _write_data_rate = 0; // Well, infinity would be better
 348                         }
 349                 }
 350
 351                 if (!disk_work_outstanding) {
 352                         _session.refresh_disk_space ();
 353                 }
 354
 355
 356                 {
 357                         Glib::Mutex::Lock lm (request_lock);
 358
 359                         if (should_run && (disk_work_outstanding || transport_work_requested())) {
 360 //                              for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 361 //                                      cerr << "AFTER " << (*i)->name() << ": pb = " << (*i)->playback_buffer_load() << " cp = " << (*i)->capture_buffer_load() << endl;
 362 //                              }
 363
 364                                 goto restart;
 365                         }
 366
 367                         paused.signal();
 368                 }
 369
 370                 empty_pool_trash ();
 371         }
 372
 373         pthread_exit_pbd (0);
 374         /*NOTREACHED*/
 375         return (0);
 376 }
 377
 378 void
 379 Butler::schedule_transport_work ()
 380 {
 381         g_atomic_int_inc (&should_do_transport_work);
 382         summon ();
 383 }
 384
 385 void
 386 Butler::summon ()
 387 {
 388         char c = Request::Run;
 389         (void) ::write (request_pipe[1], &c, 1);
 390 }
 391
 392 void
 393 Butler::stop ()
 394 {
 395         Glib::Mutex::Lock lm (request_lock);
 396         char c = Request::Pause;
 397         (void) ::write (request_pipe[1], &c, 1);
 398         paused.wait(request_lock);
 399 }
 400
 401 void
 402 Butler::wait_until_finished ()
 403 {
 404         Glib::Mutex::Lock lm (request_lock);
 405         char c = Request::Wake;
 406         (void) ::write (request_pipe[1], &c, 1);
 407         paused.wait(request_lock);
 408 }
 409
 410 bool
 411 Butler::transport_work_requested () const
 412 {
 413         return g_atomic_int_get(&should_do_transport_work);
 414 }
 415
 416 float
 417 Butler::read_data_rate () const
 418 {
 419         /* disk i/o in excess of 10000MB/sec indicate the buffer cache
 420            in action. ignore it.
 421         */
 422         return _read_data_rate > 10485.7600000f ? 0.0f : _read_data_rate;
 423 }
 424
 425 float
 426 Butler::write_data_rate () const
 427 {
 428         /* disk i/o in excess of 10000MB/sec indicate the buffer cache
 429            in action. ignore it.
 430         */
 431         return _write_data_rate > 10485.7600000f ? 0.0f : _write_data_rate;
 432 }
 433
 434 void
 435 Butler::empty_pool_trash ()
 436 {
 437         /* look in the trash, deleting empty pools until we come to one that is not empty */
 438
 439         RingBuffer<CrossThreadPool*>::rw_vector vec;
 440         pool_trash.get_read_vector (&vec);
 441
 442         guint deleted = 0;
 443
 444         for (int i = 0; i < 2; ++i) {
 445                 for (guint j = 0; j < vec.len[i]; ++j) {
 446                         if (vec.buf[i][j]->empty()) {
 447                                 delete vec.buf[i][j];
 448                                 ++deleted;
 449                         } else {
 450                                 /* found a non-empty pool, so stop deleting */
 451                                 if (deleted) {
 452                                         pool_trash.increment_read_idx (deleted);
 453                                 }
 454                                 return;
 455                         }
 456                 }
 457         }
 458
 459         if (deleted) {
 460                 pool_trash.increment_read_idx (deleted);
 461         }
 462 }
 463
 464 void
 465 Butler::drop_references ()
 466 {
 467         SessionEvent::pool->set_trash (0);
 468 }
 469
 470
 471 } // namespace ARDOUR
 472