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
  32 #include "i18n.h"
  33
  34 using namespace PBD;
  35
  36 static float _read_data_rate;
  37 static float _write_data_rate;
  38
  39 namespace ARDOUR {
  40
  41 Butler::Butler(Session& s)
  42         : SessionHandleRef (s)
  43         , thread(0)
  44         , audio_dstream_buffer_size(0)
  45         , midi_dstream_buffer_size(0)
  46 {
  47         g_atomic_int_set(&should_do_transport_work, 0);
  48 }
  49
  50 Butler::~Butler()
  51 {
  52         terminate_thread ();
  53 }
  54
  55 int
  56 Butler::start_thread()
  57 {
  58         const float rate = (float)_session.frame_rate();
  59
  60         /* size is in Samples, not bytes */
  61         audio_dstream_buffer_size = (uint32_t) floor (Config->get_audio_track_buffer_seconds() * rate);
  62
  63         /* size is in bytes
  64          * XXX: Jack needs to tell us the MIDI buffer size
  65          * (i.e. how many MIDI bytes we might see in a cycle)
  66          */
  67         midi_dstream_buffer_size = (uint32_t) floor (Config->get_midi_track_buffer_seconds() * rate);
  68
  69         MidiDiskstream::set_readahead_frames ((nframes_t)(Config->get_midi_readahead() * rate));
  70
  71         Crossfade::set_buffer_size (audio_dstream_buffer_size);
  72
  73         should_run = false;
  74
  75         if (pipe (request_pipe)) {
  76                 error << string_compose(_("Cannot create transport request signal pipe (%1)"),
  77                                 strerror (errno)) << endmsg;
  78                 return -1;
  79         }
  80
  81         if (fcntl (request_pipe[0], F_SETFL, O_NONBLOCK)) {
  82                 error << string_compose(_("UI: cannot set O_NONBLOCK on butler request pipe (%1)"),
  83                                 strerror (errno)) << endmsg;
  84                 return -1;
  85         }
  86
  87         if (fcntl (request_pipe[1], F_SETFL, O_NONBLOCK)) {
  88                 error << string_compose(_("UI: cannot set O_NONBLOCK on butler request pipe (%1)"),
  89                                 strerror (errno)) << endmsg;
  90                 return -1;
  91         }
  92
  93         if (pthread_create_and_store ("disk butler", &thread, _thread_work, this)) {
  94                 error << _("Session: could not create butler thread") << endmsg;
  95                 return -1;
  96         }
  97
  98         //pthread_detach (thread);
  99
 100         return 0;
 101 }
 102
 103 void
 104 Butler::terminate_thread ()
 105 {
 106         if (thread) {
 107                 void* status;
 108                 const char c = Request::Quit;
 109                 ::write (request_pipe[1], &c, 1);
 110                 pthread_join (thread, &status);
 111         }
 112 }
 113
 114 void *
 115 Butler::_thread_work (void* arg)
 116 {
 117         SessionEvent::create_per_thread_pool ("butler events", 64);
 118         return ((Butler *) arg)->thread_work ();
 119 }
 120
 121 void *
 122 Butler::thread_work ()
 123 {
 124         uint32_t err = 0;
 125         int32_t bytes;
 126         bool compute_io;
 127         microseconds_t begin, end;
 128
 129         struct pollfd pfd[1];
 130         bool disk_work_outstanding = false;
 131         Session::DiskstreamList::iterator i;
 132
 133         while (true) {
 134                 pfd[0].fd = request_pipe[0];
 135                 pfd[0].events = POLLIN|POLLERR|POLLHUP;
 136
 137                 if (poll (pfd, 1, (disk_work_outstanding ? 0 : -1)) < 0) {
 138
 139                         if (errno == EINTR) {
 140                                 continue;
 141                         }
 142
 143                         error << string_compose (_("poll on butler request pipe failed (%1)"),
 144                                           strerror (errno))
 145                               << endmsg;
 146                         break;
 147                 }
 148
 149                 if (pfd[0].revents & ~POLLIN) {
 150                         error << string_compose (_("Error on butler thread request pipe: fd=%1 err=%2"), pfd[0].fd, pfd[0].revents) << endmsg;
 151                         break;
 152                 }
 153
 154                 if (pfd[0].revents & POLLIN) {
 155
 156                         char req;
 157
 158                         /* empty the pipe of all current requests */
 159
 160                         while (1) {
 161                                 size_t nread = ::read (request_pipe[0], &req, sizeof (req));
 162                                 if (nread == 1) {
 163
 164                                         switch ((Request::Type) req) {
 165
 166                                         case Request::Wake:
 167                                                 break;
 168
 169                                         case Request::Run:
 170                                                 should_run = true;
 171                                                 break;
 172
 173                                         case Request::Pause:
 174                                                 should_run = false;
 175                                                 break;
 176
 177                                         case Request::Quit:
 178                                                 pthread_exit_pbd (0);
 179                                                 /*NOTREACHED*/
 180                                                 break;
 181
 182                                         default:
 183                                                 break;
 184                                         }
 185
 186                                 } else if (nread == 0) {
 187                                         break;
 188                                 } else if (errno == EAGAIN) {
 189                                         break;
 190                                 } else {
 191                                         fatal << _("Error reading from butler request pipe") << endmsg;
 192                                         /*NOTREACHED*/
 193                                 }
 194                         }
 195                 }
 196
 197                 if (transport_work_requested()) {
 198                         _session.butler_transport_work ();
 199                 }
 200
 201                 disk_work_outstanding = false;
 202                 bytes = 0;
 203                 compute_io = true;
 204
 205                 begin = get_microseconds();
 206
 207                 boost::shared_ptr<Session::DiskstreamList> dsl = _session.diskstream_list().reader ();
 208
 209 //              for (i = dsl->begin(); i != dsl->end(); ++i) {
 210 //                      cerr << "BEFORE " << (*i)->name() << ": pb = " << (*i)->playback_buffer_load() << " cp = " << (*i)->capture_buffer_load() << endl;
 211 //              }
 212
 213                 for (i = dsl->begin(); !transport_work_requested() && should_run && i != dsl->end(); ++i) {
 214
 215                         boost::shared_ptr<Diskstream> ds = *i;
 216
 217                         /* don't read inactive tracks */
 218
 219                         boost::shared_ptr<IO> io = ds->io();
 220
 221                         if (io && !io->active()) {
 222                                 continue;
 223                         }
 224
 225                         switch (ds->do_refill ()) {
 226                         case 0:
 227                                 bytes += ds->read_data_count();
 228                                 break;
 229                         case 1:
 230                                 bytes += ds->read_data_count();
 231                                 disk_work_outstanding = true;
 232                                 break;
 233
 234                         default:
 235                                 compute_io = false;
 236                                 error << string_compose(_("Butler read ahead failure on dstream %1"), (*i)->name()) << endmsg;
 237                                 break;
 238                         }
 239
 240                 }
 241
 242                 if (i != dsl->end()) {
 243                         /* we didn't get to all the streams */
 244                         disk_work_outstanding = true;
 245                 }
 246
 247                 if (!err && transport_work_requested()) {
 248                         continue;
 249                 }
 250
 251                 if (compute_io) {
 252                         end = get_microseconds();
 253                         if (end - begin > 0) {
 254                                 _read_data_rate = (float) bytes / (float) (end - begin);
 255                         } else {
 256                                 _read_data_rate = 0; // infinity better
 257                         }
 258                 }
 259
 260                 bytes = 0;
 261                 compute_io = true;
 262                 begin = get_microseconds();
 263
 264                 for (i = dsl->begin(); !transport_work_requested() && should_run && i != dsl->end(); ++i) {
 265                         // cerr << "write behind for " << (*i)->name () << endl;
 266
 267                         /* note that we still try to flush diskstreams attached to inactive routes
 268                          */
 269
 270                         switch ((*i)->do_flush (ButlerContext)) {
 271                         case 0:
 272                                 bytes += (*i)->write_data_count();
 273                                 break;
 274                         case 1:
 275                                 bytes += (*i)->write_data_count();
 276                                 disk_work_outstanding = true;
 277                                 break;
 278
 279                         default:
 280                                 err++;
 281                                 compute_io = false;
 282                                 error << string_compose(_("Butler write-behind failure on dstream %1"), (*i)->name()) << endmsg;
 283                                 /* don't break - try to flush all streams in case they
 284                                    are split across disks.
 285                                 */
 286                         }
 287                 }
 288
 289                 if (err && _session.actively_recording()) {
 290                         /* stop the transport and try to catch as much possible
 291                            captured state as we can.
 292                         */
 293                         _session.request_stop ();
 294                 }
 295
 296                 if (i != dsl->end()) {
 297                         /* we didn't get to all the streams */
 298                         disk_work_outstanding = true;
 299                 }
 300
 301                 if (!err && transport_work_requested()) {
 302                         continue;
 303                 }
 304
 305                 if (compute_io) {
 306                         // there are no apparent users for this calculation?
 307                         end = get_microseconds();
 308                         if (end - begin > 0) {
 309                                 _write_data_rate = (float) bytes / (float) (end - begin);
 310                         } else {
 311                                 _write_data_rate = 0; // Well, infinity would be better
 312                         }
 313                 }
 314
 315                 if (!disk_work_outstanding) {
 316                         _session.refresh_disk_space ();
 317                 }
 318
 319
 320                 {
 321                         Glib::Mutex::Lock lm (request_lock);
 322
 323                         if (should_run && (disk_work_outstanding || transport_work_requested())) {
 324 //                              for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 325 //                                      cerr << "AFTER " << (*i)->name() << ": pb = " << (*i)->playback_buffer_load() << " cp = " << (*i)->capture_buffer_load() << endl;
 326 //                              }
 327
 328                                 continue;
 329                         }
 330
 331                         paused.signal();
 332                 }
 333         }
 334
 335         pthread_exit_pbd (0);
 336         /*NOTREACHED*/
 337         return (0);
 338 }
 339
 340 void
 341 Butler::schedule_transport_work ()
 342 {
 343         g_atomic_int_inc (&should_do_transport_work);
 344         summon ();
 345 }
 346
 347 void
 348 Butler::summon ()
 349 {
 350         char c = Request::Run;
 351         ::write (request_pipe[1], &c, 1);
 352 }
 353
 354 void
 355 Butler::stop ()
 356 {
 357         Glib::Mutex::Lock lm (request_lock);
 358         char c = Request::Pause;
 359         ::write (request_pipe[1], &c, 1);
 360         paused.wait(request_lock);
 361 }
 362
 363 void
 364 Butler::wait_until_finished ()
 365 {
 366         Glib::Mutex::Lock lm (request_lock);
 367         char c = Request::Wake;
 368         ::write (request_pipe[1], &c, 1);
 369         paused.wait(request_lock);
 370 }
 371
 372 bool
 373 Butler::transport_work_requested () const
 374 {
 375         return g_atomic_int_get(&should_do_transport_work);
 376 }
 377
 378 float
 379 Butler::read_data_rate () const
 380 {
 381         /* disk i/o in excess of 10000MB/sec indicate the buffer cache
 382            in action. ignore it.
 383         */
 384         return _read_data_rate > 10485.7600000f ? 0.0f : _read_data_rate;
 385 }
 386
 387 float
 388 Butler::write_data_rate () const
 389 {
 390         /* disk i/o in excess of 10000MB/sec indicate the buffer cache
 391            in action. ignore it.
 392         */
 393         return _write_data_rate > 10485.7600000f ? 0.0f : _write_data_rate;
 394 }
 395
 396 } // namespace ARDOUR