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