1 /* 2 * Copyright (c) 2015 Dario Casalinuovo <b.vitruvio@gmail.com> 3 * Copyright (c) 2002, 2003 Marcus Overhagen <Marcus@Overhagen.de> 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining 6 * a copy of this software and associated documentation files or portions 7 * thereof (the "Software"), to deal in the Software without restriction, 8 * including without limitation the rights to use, copy, modify, merge, 9 * publish, distribute, sublicense, and/or sell copies of the Software, 10 * and to permit persons to whom the Software is furnished to do so, subject 11 * to the following conditions: 12 * 13 * * Redistributions of source code must retain the above copyright notice, 14 * this list of conditions and the following disclaimer. 15 * 16 * * Redistributions in binary form must reproduce the above copyright notice 17 * in the binary, as well as this list of conditions and the following 18 * disclaimer in the documentation and/or other materials provided with 19 * the distribution. 20 * 21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 22 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 24 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 27 * THE SOFTWARE. 28 * 29 */ 30 31 #include <MediaEventLooper.h> 32 #include <TimeSource.h> 33 #include <scheduler.h> 34 #include <Buffer.h> 35 #include <ServerInterface.h> 36 #include "debug.h" 37 38 /************************************************************* 39 * protected BMediaEventLooper 40 *************************************************************/ 41 42 /* virtual */ 43 BMediaEventLooper::~BMediaEventLooper() 44 { 45 CALLED(); 46 47 // don't call Quit(); here, except if the user was stupid 48 if (fControlThread != -1) { 49 printf("You MUST call BMediaEventLooper::Quit() in your destructor!\n"); 50 Quit(); 51 } 52 } 53 54 /* explicit */ 55 BMediaEventLooper::BMediaEventLooper(uint32 apiVersion) : 56 BMediaNode("called by BMediaEventLooper"), 57 fControlThread(-1), 58 fCurrentPriority(B_URGENT_PRIORITY), 59 fSetPriority(B_URGENT_PRIORITY), 60 fRunState(B_UNREGISTERED), 61 fEventLatency(0), 62 fSchedulingLatency(0), 63 fBufferDuration(0), 64 fOfflineTime(0), 65 fApiVersion(apiVersion) 66 { 67 CALLED(); 68 fEventQueue.SetCleanupHook(BMediaEventLooper::_CleanUpEntry, this); 69 fRealTimeQueue.SetCleanupHook(BMediaEventLooper::_CleanUpEntry, this); 70 } 71 72 /* virtual */ void 73 BMediaEventLooper::NodeRegistered() 74 { 75 CALLED(); 76 // Calling Run() should be done by the derived class, 77 // at least that's how it is documented by the BeBook. 78 // It appears that BeOS R5 called it here. Calling Run() 79 // twice doesn't hurt, and some nodes need it to be called here. 80 Run(); 81 } 82 83 84 /* virtual */ void 85 BMediaEventLooper::Start(bigtime_t performance_time) 86 { 87 CALLED(); 88 // This hook function is called when a node is started 89 // by a call to the BMediaRoster. The specified 90 // performanceTime, the time at which the node 91 // should start running, may be in the future. 92 fEventQueue.AddEvent(media_timed_event(performance_time, BTimedEventQueue::B_START)); 93 } 94 95 96 /* virtual */ void 97 BMediaEventLooper::Stop(bigtime_t performance_time, 98 bool immediate) 99 { 100 CALLED(); 101 // This hook function is called when a node is stopped 102 // by a call to the BMediaRoster. The specified performanceTime, 103 // the time at which the node should stop, may be in the future. 104 // If immediate is true, your node should ignore the performanceTime 105 // value and synchronously stop performance. When Stop() returns, 106 // you're promising not to write into any BBuffers you may have 107 // received from your downstream consumers, and you promise not 108 // to send any more buffers until Start() is called again. 109 110 if (immediate) { 111 // always be sure to add to the front of the queue so we can make sure it is 112 // handled before any buffers are sent! 113 performance_time = 0; 114 } 115 fEventQueue.AddEvent(media_timed_event(performance_time, BTimedEventQueue::B_STOP)); 116 } 117 118 119 /* virtual */ void 120 BMediaEventLooper::Seek(bigtime_t media_time, 121 bigtime_t performance_time) 122 { 123 CALLED(); 124 // This hook function is called when a node is asked to seek to 125 // the specified mediaTime by a call to the BMediaRoster. 126 // The specified performanceTime, the time at which the node 127 // should begin the seek operation, may be in the future. 128 fEventQueue.AddEvent(media_timed_event(performance_time, BTimedEventQueue::B_SEEK, NULL, 129 BTimedEventQueue::B_NO_CLEANUP, 0, media_time, NULL)); 130 } 131 132 133 /* virtual */ void 134 BMediaEventLooper::TimeWarp(bigtime_t at_real_time, 135 bigtime_t to_performance_time) 136 { 137 CALLED(); 138 // This hook function is called when the time source to which the 139 // node is slaved is repositioned (via a seek operation) such that 140 // there will be a sudden jump in the performance time progression 141 // as seen by the node. The to_performance_time argument indicates 142 // the new performance time; the change should occur at the real 143 // time specified by the at_real_time argument. 144 145 // place in the realtime queue 146 fRealTimeQueue.AddEvent(media_timed_event(at_real_time, BTimedEventQueue::B_WARP, 147 NULL, BTimedEventQueue::B_NO_CLEANUP, 0, to_performance_time, NULL)); 148 149 // BeBook: Your implementation of TimeWarp() should call through to BMediaNode::TimeWarp() 150 // BeBook: as well as all other inherited forms of TimeWarp() 151 // XXX should we do this here? 152 BMediaNode::TimeWarp(at_real_time, to_performance_time); 153 } 154 155 156 /* virtual */ status_t 157 BMediaEventLooper::AddTimer(bigtime_t at_performance_time, 158 int32 cookie) 159 { 160 CALLED(); 161 162 media_timed_event event(at_performance_time, 163 BTimedEventQueue::B_TIMER, NULL, 164 BTimedEventQueue::B_EXPIRE_TIMER); 165 event.data = cookie; 166 return EventQueue()->AddEvent(event); 167 } 168 169 170 /* virtual */ void 171 BMediaEventLooper::SetRunMode(run_mode mode) 172 { 173 CALLED(); 174 // The SetRunMode() hook function is called when someone requests that your node's run mode be changed. 175 176 // bump or reduce priority when switching from/to offline run mode 177 int32 priority; 178 priority = (mode == B_OFFLINE) ? min_c(B_NORMAL_PRIORITY, fSetPriority) : fSetPriority; 179 if (priority != fCurrentPriority) { 180 fCurrentPriority = priority; 181 if (fControlThread > 0) { 182 set_thread_priority(fControlThread, fCurrentPriority); 183 fSchedulingLatency = estimate_max_scheduling_latency(fControlThread); 184 printf("BMediaEventLooper: SchedulingLatency is %" B_PRId64 "\n", 185 fSchedulingLatency); 186 } 187 } 188 189 BMediaNode::SetRunMode(mode); 190 } 191 192 193 /* virtual */ void 194 BMediaEventLooper::CleanUpEvent(const media_timed_event *event) 195 { 196 CALLED(); 197 // Implement this function to clean up after custom events you've created 198 // and added to your queue. It's called when a custom event is removed from 199 // the queue, to let you handle any special tidying-up that the event might require. 200 } 201 202 203 /* virtual */ bigtime_t 204 BMediaEventLooper::OfflineTime() 205 { 206 CALLED(); 207 return fOfflineTime; 208 } 209 210 211 /* virtual */ void 212 BMediaEventLooper::ControlLoop() 213 { 214 CALLED(); 215 216 status_t err = B_OK; 217 bigtime_t waitUntil = B_INFINITE_TIMEOUT; 218 bool hasRealtime = false; 219 bool hasEvent = false; 220 bool hasBooted = false; 221 222 // While there are no events or it is not time for the earliest event, 223 // process messages using WaitForMessages. Whenever this funtion times out, 224 // we need to handle the next event 225 226 fSchedulingLatency = estimate_max_scheduling_latency(fControlThread); 227 while (RunState() != B_QUITTING) { 228 if (err == B_TIMED_OUT 229 || err == B_WOULD_BLOCK) { 230 // NOTE: The reference for doing the lateness calculus this way can 231 // be found in the BeBook article "A BMediaEventLooper Example". 232 // The value which we are going to calculate, is referred there as 233 // 'lateness'. 234 media_timed_event event; 235 if (hasEvent) 236 err = fEventQueue.RemoveFirstEvent(&event); 237 else if (hasRealtime) 238 err = fRealTimeQueue.RemoveFirstEvent(&event); 239 240 if (err == B_OK) { 241 // The general idea of lateness is to allow 242 // the client code to detect when the buffer 243 // is handled late or early. What we add is 244 // that the code log the time at which the 245 // current event is added to the queue. This 246 // allow us to detect cyclic/stagnant latency 247 // in the meantime, so that the client can 248 // notify to the producer only the portion 249 // that might be attributable. 250 bigtime_t lateness = 0; 251 if (waitUntil > 0) { 252 lateness = waitUntil - TimeSource()->RealTime(); 253 if (lateness > 0) { 254 bigtime_t enqueueLatency 255 = event.enqueue_time - waitUntil; 256 if (enqueueLatency > 0) 257 lateness += enqueueLatency; 258 } 259 } 260 DispatchEvent(&event, -lateness, hasRealtime); 261 } 262 } else if (err != B_OK) 263 return; 264 265 // BMediaEventLooper compensates your performance time by adding 266 // the event latency (see SetEventLatency()) and the scheduling 267 // latency (or, for real-time events, only the scheduling latency). 268 269 hasRealtime = fRealTimeQueue.HasEvents(); 270 hasEvent = fEventQueue.HasEvents(); 271 272 if (hasEvent) { 273 waitUntil = TimeSource()->RealTimeFor( 274 fEventQueue.FirstEventTime(), 275 fEventLatency + fSchedulingLatency); 276 277 // The first event we handle will have 278 // a negative startup wait. In this case 279 // we just check the port and let the 280 // first event to be executed just now. 281 if (!hasBooted && waitUntil < 0) { 282 waitUntil = 0; 283 hasBooted = true; 284 } 285 } else if (!hasRealtime) 286 waitUntil = B_INFINITE_TIMEOUT; 287 288 if (hasRealtime) { 289 bigtime_t realtimeWait = fRealTimeQueue.FirstEventTime() 290 - fSchedulingLatency; 291 292 if (!hasEvent || realtimeWait <= waitUntil) { 293 waitUntil = realtimeWait; 294 hasEvent = false; 295 } else 296 hasRealtime = false; 297 } 298 err = WaitForMessage(waitUntil); 299 } 300 } 301 302 303 thread_id 304 BMediaEventLooper::ControlThread() 305 { 306 CALLED(); 307 return fControlThread; 308 } 309 310 /************************************************************* 311 * protected BMediaEventLooper 312 *************************************************************/ 313 314 315 BTimedEventQueue * 316 BMediaEventLooper::EventQueue() 317 { 318 CALLED(); 319 return &fEventQueue; 320 } 321 322 323 BTimedEventQueue * 324 BMediaEventLooper::RealTimeQueue() 325 { 326 CALLED(); 327 return &fRealTimeQueue; 328 } 329 330 331 int32 332 BMediaEventLooper::Priority() const 333 { 334 CALLED(); 335 return fCurrentPriority; 336 } 337 338 339 int32 340 BMediaEventLooper::RunState() const 341 { 342 PRINT(6, "CALLED BMediaEventLooper::RunState()\n"); 343 return fRunState; 344 } 345 346 347 bigtime_t 348 BMediaEventLooper::EventLatency() const 349 { 350 CALLED(); 351 return fEventLatency; 352 } 353 354 355 bigtime_t 356 BMediaEventLooper::BufferDuration() const 357 { 358 CALLED(); 359 return fBufferDuration; 360 } 361 362 363 bigtime_t 364 BMediaEventLooper::SchedulingLatency() const 365 { 366 CALLED(); 367 return fSchedulingLatency; 368 } 369 370 371 status_t 372 BMediaEventLooper::SetPriority(int32 priority) 373 { 374 CALLED(); 375 376 // clamp to a valid value 377 if (priority < 5) 378 priority = 5; 379 380 if (priority > 120) 381 priority = 120; 382 383 fSetPriority = priority; 384 fCurrentPriority = (RunMode() == B_OFFLINE) ? min_c(B_NORMAL_PRIORITY, fSetPriority) : fSetPriority; 385 386 if (fControlThread > 0) { 387 set_thread_priority(fControlThread, fCurrentPriority); 388 fSchedulingLatency = estimate_max_scheduling_latency(fControlThread); 389 printf("BMediaEventLooper: SchedulingLatency is %" B_PRId64 "\n", 390 fSchedulingLatency); 391 } 392 393 return B_OK; 394 } 395 396 397 void 398 BMediaEventLooper::SetRunState(run_state state) 399 { 400 CALLED(); 401 402 // don't allow run state changes while quitting, 403 // also needed for correct terminating of the ControlLoop() 404 if (fRunState == B_QUITTING && state != B_TERMINATED) 405 return; 406 407 fRunState = state; 408 } 409 410 411 void 412 BMediaEventLooper::SetEventLatency(bigtime_t latency) 413 { 414 CALLED(); 415 // clamp to a valid value 416 if (latency < 0) 417 latency = 0; 418 419 fEventLatency = latency; 420 write_port_etc(ControlPort(), GENERAL_PURPOSE_WAKEUP, 0, 0, B_TIMEOUT, 0); 421 } 422 423 424 void 425 BMediaEventLooper::SetBufferDuration(bigtime_t duration) 426 { 427 CALLED(); 428 fBufferDuration = duration; 429 } 430 431 432 void 433 BMediaEventLooper::SetOfflineTime(bigtime_t offTime) 434 { 435 CALLED(); 436 fOfflineTime = offTime; 437 } 438 439 440 void 441 BMediaEventLooper::Run() 442 { 443 CALLED(); 444 445 if (fControlThread != -1) 446 return; // thread already running 447 448 // until now, the run state is B_UNREGISTERED, but we need to start in B_STOPPED state. 449 SetRunState(B_STOPPED); 450 451 char threadName[32]; 452 sprintf(threadName, "%.20s control", Name()); 453 fControlThread = spawn_thread(_ControlThreadStart, threadName, fCurrentPriority, this); 454 resume_thread(fControlThread); 455 456 // get latency information 457 fSchedulingLatency = estimate_max_scheduling_latency(fControlThread); 458 } 459 460 461 void 462 BMediaEventLooper::Quit() 463 { 464 CALLED(); 465 466 if (fRunState == B_TERMINATED) 467 return; 468 469 SetRunState(B_QUITTING); 470 close_port(ControlPort()); 471 if (fControlThread != -1) { 472 status_t err; 473 wait_for_thread(fControlThread, &err); 474 fControlThread = -1; 475 } 476 SetRunState(B_TERMINATED); 477 } 478 479 480 void 481 BMediaEventLooper::DispatchEvent(const media_timed_event *event, 482 bigtime_t lateness, 483 bool realTimeEvent) 484 { 485 PRINT(6, "CALLED BMediaEventLooper::DispatchEvent()\n"); 486 487 HandleEvent(event, lateness, realTimeEvent); 488 489 switch (event->type) { 490 case BTimedEventQueue::B_START: 491 SetRunState(B_STARTED); 492 break; 493 494 case BTimedEventQueue::B_STOP: 495 SetRunState(B_STOPPED); 496 break; 497 498 case BTimedEventQueue::B_SEEK: 499 /* nothing */ 500 break; 501 502 case BTimedEventQueue::B_WARP: 503 /* nothing */ 504 break; 505 506 case BTimedEventQueue::B_TIMER: 507 TimerExpired(event->event_time, event->data); 508 break; 509 510 default: 511 break; 512 } 513 514 _DispatchCleanUp(event); 515 } 516 517 /************************************************************* 518 * private BMediaEventLooper 519 *************************************************************/ 520 521 522 /* static */ int32 523 BMediaEventLooper::_ControlThreadStart(void *arg) 524 { 525 CALLED(); 526 ((BMediaEventLooper *)arg)->SetRunState(B_STOPPED); 527 ((BMediaEventLooper *)arg)->ControlLoop(); 528 ((BMediaEventLooper *)arg)->SetRunState(B_QUITTING); 529 return 0; 530 } 531 532 533 /* static */ void 534 BMediaEventLooper::_CleanUpEntry(const media_timed_event *event, 535 void *context) 536 { 537 PRINT(6, "CALLED BMediaEventLooper::_CleanUpEntry()\n"); 538 ((BMediaEventLooper *)context)->_DispatchCleanUp(event); 539 } 540 541 542 void 543 BMediaEventLooper::_DispatchCleanUp(const media_timed_event *event) 544 { 545 PRINT(6, "CALLED BMediaEventLooper::_DispatchCleanUp()\n"); 546 547 // this function to clean up after custom events you've created 548 if (event->cleanup >= BTimedEventQueue::B_USER_CLEANUP) 549 CleanUpEvent(event); 550 } 551 552 /* 553 // unimplemented 554 BMediaEventLooper::BMediaEventLooper(const BMediaEventLooper &) 555 BMediaEventLooper &BMediaEventLooper::operator=(const BMediaEventLooper &) 556 */ 557 558 /************************************************************* 559 * protected BMediaEventLooper 560 *************************************************************/ 561 562 563 status_t 564 BMediaEventLooper::DeleteHook(BMediaNode *node) 565 { 566 CALLED(); 567 // this is the DeleteHook that gets called by the media server 568 // before the media node is deleted 569 Quit(); 570 return BMediaNode::DeleteHook(node); 571 } 572 573 /************************************************************* 574 * private BMediaEventLooper 575 *************************************************************/ 576 577 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_0(int32 arg,...) { return B_ERROR; } 578 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_1(int32 arg,...) { return B_ERROR; } 579 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_2(int32 arg,...) { return B_ERROR; } 580 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_3(int32 arg,...) { return B_ERROR; } 581 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_4(int32 arg,...) { return B_ERROR; } 582 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_5(int32 arg,...) { return B_ERROR; } 583 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_6(int32 arg,...) { return B_ERROR; } 584 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_7(int32 arg,...) { return B_ERROR; } 585 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_8(int32 arg,...) { return B_ERROR; } 586 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_9(int32 arg,...) { return B_ERROR; } 587 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_10(int32 arg,...) { return B_ERROR; } 588 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_11(int32 arg,...) { return B_ERROR; } 589 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_12(int32 arg,...) { return B_ERROR; } 590 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_13(int32 arg,...) { return B_ERROR; } 591 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_14(int32 arg,...) { return B_ERROR; } 592 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_15(int32 arg,...) { return B_ERROR; } 593 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_16(int32 arg,...) { return B_ERROR; } 594 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_17(int32 arg,...) { return B_ERROR; } 595 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_18(int32 arg,...) { return B_ERROR; } 596 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_19(int32 arg,...) { return B_ERROR; } 597 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_20(int32 arg,...) { return B_ERROR; } 598 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_21(int32 arg,...) { return B_ERROR; } 599 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_22(int32 arg,...) { return B_ERROR; } 600 status_t BMediaEventLooper::_Reserved_BMediaEventLooper_23(int32 arg,...) { return B_ERROR; } 601 602