libs/ardour/graph.cc

   1 /*
   2   Copyright (C) 2010 Paul Davis
   3   Author: Torben Hohn
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9
  10   This program is distributed in the hope that it will be useful,
  11   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13   GNU General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; if not, write to the Free Software
  17   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18
  19 */
  20 #include <stdio.h>
  21 #include <cmath>
  22
  23 #include "pbd/compose.h"
  24 #include "pbd/debug_rt_alloc.h"
  25 #include "pbd/pthread_utils.h"
  26
  27 #include "ardour/debug.h"
  28 #include "ardour/graph.h"
  29 #include "ardour/types.h"
  30 #include "ardour/session.h"
  31 #include "ardour/route.h"
  32 #include "ardour/process_thread.h"
  33 #include "ardour/audioengine.h"
  34
  35 #include "pbd/i18n.h"
  36
  37 using namespace ARDOUR;
  38 using namespace PBD;
  39 using namespace std;
  40
  41 #ifdef DEBUG_RT_ALLOC
  42 static Graph* graph = 0;
  43
  44 extern "C" {
  45
  46 int alloc_allowed ()
  47 {
  48         return !graph->in_process_thread ();
  49 }
  50
  51 }
  52 #endif
  53
  54 Graph::Graph (Session & session)
  55         : SessionHandleRef (session)
  56         , _threads_active (false)
  57         , _execution_sem ("graph_execution", 0)
  58         , _callback_start_sem ("graph_start", 0)
  59         , _callback_done_sem ("graph_done", 0)
  60         , _cleanup_sem ("graph_cleanup", 0)
  61 {
  62         pthread_mutex_init( &_trigger_mutex, NULL);
  63
  64         /* XXX: rather hacky `fix' to stop _trigger_queue.push_back() allocating
  65            memory in the RT thread.
  66         */
  67         _trigger_queue.reserve (8192);
  68
  69         _execution_tokens = 0;
  70
  71         _current_chain = 0;
  72         _pending_chain = 0;
  73         _setup_chain   = 1;
  74         _graph_empty = true;
  75
  76
  77         ARDOUR::AudioEngine::instance()->Running.connect_same_thread (engine_connections, boost::bind (&Graph::reset_thread_list, this));
  78         ARDOUR::AudioEngine::instance()->Stopped.connect_same_thread (engine_connections, boost::bind (&Graph::engine_stopped, this));
  79         ARDOUR::AudioEngine::instance()->Halted.connect_same_thread (engine_connections, boost::bind (&Graph::engine_stopped, this));
  80
  81         reset_thread_list ();
  82
  83 #ifdef DEBUG_RT_ALLOC
  84         graph = this;
  85         pbd_alloc_allowed = &::alloc_allowed;
  86 #endif
  87 }
  88
  89 void
  90 Graph::engine_stopped ()
  91 {
  92         if (AudioEngine::instance()->process_thread_count() != 0) {
  93                 drop_threads ();
  94         }
  95 }
  96
  97 /** Set up threads for running the graph */
  98 void
  99 Graph::reset_thread_list ()
 100 {
 101         uint32_t num_threads = how_many_dsp_threads ();
 102
 103         /* For now, we shouldn't be using the graph code if we only have 1 DSP thread */
 104         assert (num_threads > 1);
 105
 106         /* don't bother doing anything here if we already have the right
 107            number of threads.
 108         */
 109
 110         if (AudioEngine::instance()->process_thread_count() == num_threads) {
 111                 return;
 112         }
 113
 114         Glib::Threads::Mutex::Lock lm (_session.engine().process_lock());
 115
 116         if (AudioEngine::instance()->process_thread_count() != 0) {
 117                 drop_threads ();
 118         }
 119
 120         _threads_active = true;
 121
 122         if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::main_thread, this)) != 0) {
 123                 throw failed_constructor ();
 124         }
 125
 126         for (uint32_t i = 1; i < num_threads; ++i) {
 127                 if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::helper_thread, this))) {
 128                         throw failed_constructor ();
 129                 }
 130         }
 131 }
 132
 133 void
 134 Graph::session_going_away()
 135 {
 136         drop_threads ();
 137
 138         // now drop all references on the nodes.
 139         _nodes_rt[0].clear();
 140         _nodes_rt[1].clear();
 141         _init_trigger_list[0].clear();
 142         _init_trigger_list[1].clear();
 143         _trigger_queue.clear();
 144 }
 145
 146 void
 147 Graph::drop_threads ()
 148 {
 149         Glib::Threads::Mutex::Lock ls (_swap_mutex);
 150         _threads_active = false;
 151
 152         uint32_t thread_count = AudioEngine::instance()->process_thread_count ();
 153
 154         for (unsigned int i=0; i < thread_count; i++) {
 155                 pthread_mutex_lock (&_trigger_mutex);
 156                 _execution_sem.signal ();
 157                 pthread_mutex_unlock (&_trigger_mutex);
 158         }
 159
 160         pthread_mutex_lock (&_trigger_mutex);
 161         _callback_start_sem.signal ();
 162         pthread_mutex_unlock (&_trigger_mutex);
 163
 164         AudioEngine::instance()->join_process_threads ();
 165
 166         _execution_tokens = 0;
 167 }
 168
 169 void
 170 Graph::clear_other_chain ()
 171 {
 172         Glib::Threads::Mutex::Lock ls (_swap_mutex);
 173
 174         while (1) {
 175                 if (_setup_chain != _pending_chain) {
 176
 177                         for (node_list_t::iterator ni=_nodes_rt[_setup_chain].begin(); ni!=_nodes_rt[_setup_chain].end(); ni++) {
 178                                 (*ni)->_activation_set[_setup_chain].clear();
 179                         }
 180
 181                         _nodes_rt[_setup_chain].clear ();
 182                         _init_trigger_list[_setup_chain].clear ();
 183                         break;
 184                 }
 185                 /* setup chain == pending chain - we have
 186                    to wait till this is no longer true.
 187                 */
 188                 _cleanup_cond.wait (_swap_mutex);
 189         }
 190 }
 191
 192 void
 193 Graph::prep()
 194 {
 195         node_list_t::iterator i;
 196         int chain;
 197
 198         if (_swap_mutex.trylock()) {
 199                 // we got the swap mutex.
 200                 if (_current_chain != _pending_chain)
 201                 {
 202                         // printf ("chain swap ! %d -> %d\n", _current_chain, _pending_chain);
 203                         _setup_chain = _current_chain;
 204                         _current_chain = _pending_chain;
 205                         _cleanup_cond.signal ();
 206                 }
 207                 _swap_mutex.unlock ();
 208         }
 209
 210         chain = _current_chain;
 211
 212         _graph_empty = true;
 213         for (i=_nodes_rt[chain].begin(); i!=_nodes_rt[chain].end(); i++) {
 214                 (*i)->prep( chain);
 215                 _graph_empty = false;
 216         }
 217         _finished_refcount = _init_finished_refcount[chain];
 218
 219         /* Trigger the initial nodes for processing, which are the ones at the `input' end */
 220         pthread_mutex_lock (&_trigger_mutex);
 221         for (i=_init_trigger_list[chain].begin(); i!=_init_trigger_list[chain].end(); i++) {
 222                 /* don't use ::trigger here, as we have already locked the mutex */
 223                 _trigger_queue.push_back (i->get ());
 224         }
 225         pthread_mutex_unlock (&_trigger_mutex);
 226 }
 227
 228 void
 229 Graph::trigger (GraphNode* n)
 230 {
 231         pthread_mutex_lock (&_trigger_mutex);
 232         _trigger_queue.push_back (n);
 233         pthread_mutex_unlock (&_trigger_mutex);
 234 }
 235
 236 /** Called when a node at the `output' end of the chain (ie one that has no-one to feed)
 237  *  is finished.
 238  */
 239 void
 240 Graph::dec_ref()
 241 {
 242         if (g_atomic_int_dec_and_test (const_cast<gint*> (&_finished_refcount))) {
 243
 244                 /* We have run all the nodes that are at the `output' end of
 245                    the graph, so there is nothing more to do this time around.
 246                 */
 247
 248                 restart_cycle ();
 249         }
 250 }
 251
 252 void
 253 Graph::restart_cycle()
 254 {
 255         // we are through. wakeup our caller.
 256
 257   again:
 258         _callback_done_sem.signal ();
 259
 260         /* Block until the a process callback triggers us */
 261         _callback_start_sem.wait();
 262
 263         if (!_threads_active) {
 264                 return;
 265         }
 266
 267         prep ();
 268
 269         if (_graph_empty && _threads_active) {
 270                 goto again;
 271         }
 272
 273         // returning will restart the cycle.
 274         // starting with waking up the others.
 275 }
 276
 277 /** Rechain our stuff using a list of routes (which can be in any order) and
 278  *  a directed graph of their interconnections, which is guaranteed to be
 279  *  acyclic.
 280  */
 281
 282 void
 283 Graph::rechain (boost::shared_ptr<RouteList> routelist, GraphEdges const & edges)
 284 {
 285         Glib::Threads::Mutex::Lock ls (_swap_mutex);
 286
 287         int chain = _setup_chain;
 288         DEBUG_TRACE (DEBUG::Graph, string_compose ("============== setup %1\n", chain));
 289
 290         /* This will become the number of nodes that do not feed any other node;
 291            once we have processed this number of those nodes, we have finished.
 292         */
 293         _init_finished_refcount[chain] = 0;
 294
 295         /* This will become a list of nodes that are not fed by another node, ie
 296            those at the `input' end.
 297         */
 298         _init_trigger_list[chain].clear();
 299
 300         _nodes_rt[chain].clear();
 301
 302         /* Clear things out, and make _nodes_rt[chain] a copy of routelist */
 303         for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++) {
 304                 (*ri)->_init_refcount[chain] = 0;
 305                 (*ri)->_activation_set[chain].clear();
 306                 _nodes_rt[chain].push_back (*ri);
 307         }
 308
 309         // now add refs for the connections.
 310
 311         for (node_list_t::iterator ni = _nodes_rt[chain].begin(); ni != _nodes_rt[chain].end(); ni++) {
 312
 313                 boost::shared_ptr<Route> r = boost::dynamic_pointer_cast<Route> (*ni);
 314
 315                 /* The routes that are directly fed by r */
 316                 set<GraphVertex> fed_from_r = edges.from (r);
 317
 318                 /* Hence whether r has an output */
 319                 bool const has_output = !fed_from_r.empty ();
 320
 321                 /* Set up r's activation set */
 322                 for (set<GraphVertex>::iterator i = fed_from_r.begin(); i != fed_from_r.end(); ++i) {
 323                         r->_activation_set[chain].insert (*i);
 324                 }
 325
 326                 /* r has an input if there are some incoming edges to r in the graph */
 327                 bool const has_input = !edges.has_none_to (r);
 328
 329                 /* Increment the refcount of any route that we directly feed */
 330                 for (node_set_t::iterator ai = r->_activation_set[chain].begin(); ai != r->_activation_set[chain].end(); ai++) {
 331                         (*ai)->_init_refcount[chain] += 1;
 332                 }
 333
 334                 if (!has_input) {
 335                         /* no input, so this node needs to be triggered initially to get things going */
 336                         _init_trigger_list[chain].push_back (*ni);
 337                 }
 338
 339                 if (!has_output) {
 340                         /* no output, so this is one of the nodes that we can count off to decide
 341                            if we've finished
 342                         */
 343                         _init_finished_refcount[chain] += 1;
 344                 }
 345         }
 346
 347         _pending_chain = chain;
 348         dump(chain);
 349 }
 350
 351 /** Called by both the main thread and all helpers.
 352  *  @return true to quit, false to carry on.
 353  */
 354 bool
 355 Graph::run_one()
 356 {
 357         GraphNode* to_run;
 358
 359         pthread_mutex_lock (&_trigger_mutex);
 360         if (_trigger_queue.size()) {
 361                 to_run = _trigger_queue.back();
 362                 _trigger_queue.pop_back();
 363         } else {
 364                 to_run = 0;
 365         }
 366
 367         /* the number of threads that are asleep */
 368         int et = _execution_tokens;
 369         /* the number of nodes that need to be run */
 370         int ts = _trigger_queue.size();
 371
 372         /* hence how many threads to wake up */
 373         int wakeup = min (et, ts);
 374         /* update the number of threads that will still be sleeping */
 375         _execution_tokens -= wakeup;
 376
 377         DEBUG_TRACE(DEBUG::ProcessThreads, string_compose ("%1 signals %2\n", pthread_name(), wakeup));
 378
 379         for (int i = 0; i < wakeup; i++) {
 380                 _execution_sem.signal ();
 381         }
 382
 383         while (to_run == 0) {
 384                 _execution_tokens += 1;
 385                 pthread_mutex_unlock (&_trigger_mutex);
 386                 DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 goes to sleep\n", pthread_name()));
 387                 _execution_sem.wait ();
 388                 if (!_threads_active) {
 389                         return true;
 390                 }
 391                 DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 is awake\n", pthread_name()));
 392                 pthread_mutex_lock (&_trigger_mutex);
 393                 if (_trigger_queue.size()) {
 394                         to_run = _trigger_queue.back();
 395                         _trigger_queue.pop_back();
 396                 }
 397         }
 398         pthread_mutex_unlock (&_trigger_mutex);
 399
 400         to_run->process();
 401         to_run->finish (_current_chain);
 402
 403         DEBUG_TRACE(DEBUG::ProcessThreads, string_compose ("%1 has finished run_one()\n", pthread_name()));
 404
 405         return !_threads_active;
 406 }
 407
 408 void
 409 Graph::helper_thread()
 410 {
 411         suspend_rt_malloc_checks ();
 412         ProcessThread* pt = new ProcessThread ();
 413         resume_rt_malloc_checks ();
 414
 415         pt->get_buffers();
 416
 417         while(1) {
 418                 if (run_one()) {
 419                         break;
 420                 }
 421         }
 422
 423         pt->drop_buffers();
 424         delete pt;
 425 }
 426
 427 /** Here's the main graph thread */
 428 void
 429 Graph::main_thread()
 430 {
 431         suspend_rt_malloc_checks ();
 432         ProcessThread* pt = new ProcessThread ();
 433         resume_rt_malloc_checks ();
 434
 435         pt->get_buffers();
 436
 437 again:
 438         _callback_start_sem.wait ();
 439
 440         DEBUG_TRACE(DEBUG::ProcessThreads, "main thread is awake\n");
 441
 442         if (!_threads_active) {
 443                 return;
 444         }
 445
 446         prep ();
 447
 448         if (_graph_empty && _threads_active) {
 449                 _callback_done_sem.signal ();
 450                 DEBUG_TRACE(DEBUG::ProcessThreads, "main thread sees graph done, goes back to sleep\n");
 451                 goto again;
 452         }
 453
 454         /* This loop will run forever */
 455         while (1) {
 456                 DEBUG_TRACE(DEBUG::ProcessThreads, "main thread runs one graph node\n");
 457                 if (run_one()) {
 458                         break;
 459                 }
 460         }
 461
 462         pt->drop_buffers();
 463         delete (pt);
 464 }
 465
 466 void
 467 Graph::dump (int chain)
 468 {
 469 #ifndef NDEBUG
 470         node_list_t::iterator ni;
 471         node_set_t::iterator ai;
 472
 473         chain = _pending_chain;
 474
 475         DEBUG_TRACE (DEBUG::Graph, "--------------------------------------------Graph dump:\n");
 476         for (ni=_nodes_rt[chain].begin(); ni!=_nodes_rt[chain].end(); ni++) {
 477                 boost::shared_ptr<Route> rp = boost::dynamic_pointer_cast<Route>( *ni);
 478                 DEBUG_TRACE (DEBUG::Graph, string_compose ("GraphNode: %1  refcount: %2\n", rp->name().c_str(), (*ni)->_init_refcount[chain]));
 479                 for (ai=(*ni)->_activation_set[chain].begin(); ai!=(*ni)->_activation_set[chain].end(); ai++) {
 480                         DEBUG_TRACE (DEBUG::Graph, string_compose ("  triggers: %1\n", boost::dynamic_pointer_cast<Route>(*ai)->name().c_str()));
 481                 }
 482         }
 483
 484         DEBUG_TRACE (DEBUG::Graph, "------------- trigger list:\n");
 485         for (ni=_init_trigger_list[chain].begin(); ni!=_init_trigger_list[chain].end(); ni++) {
 486                 DEBUG_TRACE (DEBUG::Graph, string_compose ("GraphNode: %1  refcount: %2\n", boost::dynamic_pointer_cast<Route>(*ni)->name().c_str(), (*ni)->_init_refcount[chain]));
 487         }
 488
 489         DEBUG_TRACE (DEBUG::Graph, string_compose ("final activation refcount: %1\n", _init_finished_refcount[chain]));
 490 #endif
 491 }
 492
 493 int
 494 Graph::silent_process_routes (pframes_t nframes, framepos_t start_frame, framepos_t end_frame, bool& need_butler)
 495 {
 496         if (!_threads_active) return 0;
 497
 498         _process_nframes = nframes;
 499         _process_start_frame = start_frame;
 500         _process_end_frame = end_frame;
 501
 502         _process_silent = true;
 503         _process_noroll = false;
 504         _process_retval = 0;
 505         _process_need_butler = false;
 506
 507         if (!_graph_empty) {
 508                 DEBUG_TRACE(DEBUG::ProcessThreads, "wake graph for silent process\n");
 509                 _callback_start_sem.signal ();
 510                 _callback_done_sem.wait ();
 511         }
 512
 513         need_butler = _process_need_butler;
 514
 515         return _process_retval;
 516 }
 517
 518 int
 519 Graph::process_routes (pframes_t nframes, framepos_t start_frame, framepos_t end_frame, int declick, bool& need_butler)
 520 {
 521         DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("graph execution from %1 to %2 = %3\n", start_frame, end_frame, nframes));
 522
 523         if (!_threads_active) return 0;
 524
 525         _process_nframes = nframes;
 526         _process_start_frame = start_frame;
 527         _process_end_frame = end_frame;
 528         _process_declick = declick;
 529
 530         _process_silent = false;
 531         _process_noroll = false;
 532         _process_retval = 0;
 533         _process_need_butler = false;
 534
 535         DEBUG_TRACE(DEBUG::ProcessThreads, "wake graph for non-silent process\n");
 536         _callback_start_sem.signal ();
 537         _callback_done_sem.wait ();
 538
 539         DEBUG_TRACE (DEBUG::ProcessThreads, "graph execution complete\n");
 540
 541         need_butler = _process_need_butler;
 542
 543         return _process_retval;
 544 }
 545
 546 int
 547 Graph::routes_no_roll (pframes_t nframes, framepos_t start_frame, framepos_t end_frame,
 548                        bool non_rt_pending, int declick)
 549 {
 550         DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("no-roll graph execution from %1 to %2 = %3\n", start_frame, end_frame, nframes));
 551
 552         if (!_threads_active) return 0;
 553
 554         _process_nframes = nframes;
 555         _process_start_frame = start_frame;
 556         _process_end_frame = end_frame;
 557         _process_declick = declick;
 558         _process_non_rt_pending = non_rt_pending;
 559
 560         _process_silent = false;
 561         _process_noroll = true;
 562         _process_retval = 0;
 563         _process_need_butler = false;
 564
 565         DEBUG_TRACE(DEBUG::ProcessThreads, "wake graph for no-roll process\n");
 566         _callback_start_sem.signal ();
 567         _callback_done_sem.wait ();
 568
 569         return _process_retval;
 570 }
 571 void
 572 Graph::process_one_route (Route* route)
 573 {
 574         bool need_butler = false;
 575         int retval;
 576
 577         assert (route);
 578
 579         DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 runs route %2\n", pthread_name(), route->name()));
 580
 581         if (_process_silent) {
 582                 retval = route->silent_roll (_process_nframes, _process_start_frame, _process_end_frame, need_butler);
 583         } else if (_process_noroll) {
 584                 route->set_pending_declick (_process_declick);
 585                 retval = route->no_roll (_process_nframes, _process_start_frame, _process_end_frame, _process_non_rt_pending);
 586         } else {
 587                 route->set_pending_declick (_process_declick);
 588                 retval = route->roll (_process_nframes, _process_start_frame, _process_end_frame, _process_declick, need_butler);
 589         }
 590
 591         if (retval) {
 592                 _process_retval = retval;
 593         }
 594
 595         if (need_butler) {
 596                 _process_need_butler = true;
 597         }
 598 }
 599
 600 bool
 601 Graph::in_process_thread () const
 602 {
 603         return AudioEngine::instance()->in_process_thread ();
 604 }