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