1 // The MIT License (MIT) 2 // 3 // Copyright (c) 2015 Sergey Makeev, Vadim Slyusarev 4 // 5 // Permission is hereby granted, free of charge, to any person obtaining a copy 6 // of this software and associated documentation files (the "Software"), to deal 7 // in the Software without restriction, including without limitation the rights 8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 // copies of the Software, and to permit persons to whom the Software is 10 // furnished to do so, subject to the following conditions: 11 // 12 // The above copyright notice and this permission notice shall be included in 13 // all copies or substantial portions of the Software. 14 // 15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 21 // THE SOFTWARE. 22 23 #include <MTScheduler.h> 24 #include <MTStaticVector.h> 25 #include <string.h> // for memset 26 27 28 // Enable low latency experimental wait code path. 29 // Look like low latency hybrid wait is work better for PS4/X1, but a little worse on PC 30 //#define MT_LOW_LATENCY_EXPERIMENTAL_WAIT (1) 31 32 33 namespace MT 34 { 35 mt_thread_local uint32 isWorkerThreadTLS = 0; 36 37 38 #ifdef MT_INSTRUMENTED_BUILD 39 TaskScheduler::TaskScheduler(uint32 workerThreadsCount, WorkerThreadParams* workerParameters, IProfilerEventListener* listener, TaskStealingMode::Type stealMode) 40 #else 41 TaskScheduler::TaskScheduler(uint32 workerThreadsCount, WorkerThreadParams* workerParameters, TaskStealingMode::Type stealMode) 42 #endif 43 : roundRobinThreadIndex(0) 44 , startedThreadsCount(0) 45 , taskStealingDisabled(stealMode == TaskStealingMode::DISABLED) 46 { 47 48 #ifdef MT_INSTRUMENTED_BUILD 49 profilerEventListener = listener; 50 #endif 51 52 if (workerThreadsCount != 0) 53 { 54 threadsCount.StoreRelaxed( MT::Clamp(workerThreadsCount, (uint32)1, (uint32)MT_MAX_THREAD_COUNT) ); 55 } else 56 { 57 //query number of processor 58 threadsCount.StoreRelaxed( (uint32)MT::Clamp(Thread::GetNumberOfHardwareThreads() - 1, 1, (int)MT_MAX_THREAD_COUNT) ); 59 } 60 61 62 uint32 fiberIndex = 0; 63 64 // create fiber pool (fibers with standard stack size) 65 for (uint32 i = 0; i < MT_MAX_STANDART_FIBERS_COUNT; i++) 66 { 67 FiberContext& context = standartFiberContexts[i]; 68 context.fiber.Create(MT_STANDART_FIBER_STACK_SIZE, FiberMain, &context); 69 context.fiberIndex = fiberIndex; 70 bool res = standartFibersAvailable.TryPush( &context ); 71 MT_USED_IN_ASSERT(res); 72 MT_ASSERT(res == true, "Can't add fiber to storage"); 73 fiberIndex++; 74 } 75 76 // create fiber pool (fibers with extended stack size) 77 for (uint32 i = 0; i < MT_MAX_EXTENDED_FIBERS_COUNT; i++) 78 { 79 FiberContext& context = extendedFiberContexts[i]; 80 context.fiber.Create(MT_EXTENDED_FIBER_STACK_SIZE, FiberMain, &context); 81 context.fiberIndex = fiberIndex; 82 bool res = extendedFibersAvailable.TryPush( &context ); 83 MT_USED_IN_ASSERT(res); 84 MT_ASSERT(res == true, "Can't add fiber to storage"); 85 fiberIndex++; 86 } 87 88 #ifdef MT_INSTRUMENTED_BUILD 89 NotifyFibersCreated(MT_MAX_STANDART_FIBERS_COUNT + MT_MAX_EXTENDED_FIBERS_COUNT); 90 #endif 91 92 for (int16 i = 0; i < TaskGroup::MT_MAX_GROUPS_COUNT; i++) 93 { 94 if (i != TaskGroup::DEFAULT) 95 { 96 bool res = availableGroups.TryPush( TaskGroup(i) ); 97 MT_USED_IN_ASSERT(res); 98 MT_ASSERT(res == true, "Can't add group to storage"); 99 } 100 } 101 102 #if MT_GROUP_DEBUG 103 groupStats[TaskGroup::DEFAULT].SetDebugIsFree(false); 104 #endif 105 106 // create worker thread pool 107 int32 totalThreadsCount = GetWorkersCount(); 108 109 #ifdef MT_INSTRUMENTED_BUILD 110 NotifyThreadsCreated(totalThreadsCount); 111 #endif 112 113 for (int32 i = 0; i < totalThreadsCount; i++) 114 { 115 threadContext[i].SetThreadIndex(i); 116 threadContext[i].taskScheduler = this; 117 118 uint32 threadCore = i; 119 ThreadPriority::Type priority = ThreadPriority::DEFAULT; 120 if (workerParameters != nullptr) 121 { 122 const WorkerThreadParams& params = workerParameters[i]; 123 124 threadCore = params.core; 125 priority = params.priority; 126 } 127 128 threadContext[i].thread.Start( MT_SCHEDULER_STACK_SIZE, WorkerThreadMain, &threadContext[i], threadCore, priority); 129 } 130 } 131 132 133 TaskScheduler::~TaskScheduler() 134 { 135 int32 totalThreadsCount = GetWorkersCount(); 136 for (int32 i = 0; i < totalThreadsCount; i++) 137 { 138 threadContext[i].state.Store(internal::ThreadState::EXIT); 139 threadContext[i].hasNewTasksEvent.Signal(); 140 } 141 142 for (int32 i = 0; i < totalThreadsCount; i++) 143 { 144 threadContext[i].thread.Join(); 145 } 146 } 147 148 FiberContext* TaskScheduler::RequestFiberContext(internal::GroupedTask& task) 149 { 150 FiberContext *fiberContext = task.awaitingFiber; 151 if (fiberContext) 152 { 153 task.awaitingFiber = nullptr; 154 return fiberContext; 155 } 156 157 MT::StackRequirements::Type stackRequirements = task.desc.stackRequirements; 158 159 fiberContext = nullptr; 160 bool res = false; 161 MT_USED_IN_ASSERT(res); 162 switch(stackRequirements) 163 { 164 case MT::StackRequirements::STANDARD: 165 res = standartFibersAvailable.TryPop(fiberContext); 166 MT_ASSERT(res, "Can't get more standard fibers!"); 167 break; 168 case MT::StackRequirements::EXTENDED: 169 res = extendedFibersAvailable.TryPop(fiberContext); 170 MT_ASSERT(res, "Can't get more extended fibers!"); 171 break; 172 default: 173 MT_REPORT_ASSERT("Unknown stack requrements"); 174 } 175 176 MT_ASSERT(fiberContext != nullptr, "Can't get more fibers. Too many tasks in flight simultaneously?"); 177 178 fiberContext->currentTask = task.desc; 179 fiberContext->currentGroup = task.group; 180 fiberContext->parentFiber = task.parentFiber; 181 fiberContext->stackRequirements = stackRequirements; 182 return fiberContext; 183 } 184 185 void TaskScheduler::ReleaseFiberContext(FiberContext*&& fiberContext) 186 { 187 MT_ASSERT(fiberContext, "Can't release nullptr Fiber. fiberContext is nullptr"); 188 189 MT::StackRequirements::Type stackRequirements = fiberContext->stackRequirements; 190 fiberContext->Reset(); 191 192 MT_ASSERT(fiberContext != nullptr, "Fiber context can't be nullptr"); 193 194 bool res = false; 195 MT_USED_IN_ASSERT(res); 196 switch(stackRequirements) 197 { 198 case MT::StackRequirements::STANDARD: 199 res = standartFibersAvailable.TryPush(std::move(fiberContext)); 200 break; 201 case MT::StackRequirements::EXTENDED: 202 res = extendedFibersAvailable.TryPush(std::move(fiberContext)); 203 break; 204 default: 205 MT_REPORT_ASSERT("Unknown stack requrements"); 206 } 207 208 MT_USED_IN_ASSERT(res); 209 MT_ASSERT(res != false, "Can't return fiber to storage"); 210 } 211 212 FiberContext* TaskScheduler::ExecuteTask(internal::ThreadContext& threadContext, FiberContext* fiberContext) 213 { 214 MT_ASSERT(threadContext.threadId.IsEqual(ThreadId::Self()), "Thread context sanity check failed"); 215 216 MT_ASSERT(fiberContext, "Invalid fiber context"); 217 MT_ASSERT(fiberContext->currentTask.IsValid(), "Invalid task"); 218 219 // Set actual thread context to fiber 220 fiberContext->SetThreadContext(&threadContext); 221 222 // Update task status 223 fiberContext->SetStatus(FiberTaskStatus::RUNNED); 224 225 MT_ASSERT(fiberContext->GetThreadContext()->threadId.IsEqual(ThreadId::Self()), "Thread context sanity check failed"); 226 227 const void* poolUserData = fiberContext->currentTask.userData; 228 TPoolTaskDestroy poolDestroyFunc = fiberContext->currentTask.poolDestroyFunc; 229 230 #ifdef MT_INSTRUMENTED_BUILD 231 //threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::SUSPEND); 232 threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::STOP); 233 #endif 234 235 // Run current task code 236 Fiber::SwitchTo(threadContext.schedulerFiber, fiberContext->fiber); 237 238 #ifdef MT_INSTRUMENTED_BUILD 239 //threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::RESUME); 240 threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::START); 241 #endif 242 243 // If task was done 244 FiberTaskStatus::Type taskStatus = fiberContext->GetStatus(); 245 if (taskStatus == FiberTaskStatus::FINISHED) 246 { 247 //destroy task (call dtor) for "fire and forget" type of task from TaskPool 248 if (poolDestroyFunc != nullptr) 249 { 250 poolDestroyFunc(poolUserData); 251 } 252 253 TaskGroup taskGroup = fiberContext->currentGroup; 254 255 TaskScheduler::TaskGroupDescription & groupDesc = threadContext.taskScheduler->GetGroupDesc(taskGroup); 256 257 // Update group status 258 int groupTaskCount = groupDesc.Dec(); 259 MT_ASSERT(groupTaskCount >= 0, "Sanity check failed!"); 260 if (groupTaskCount == 0) 261 { 262 fiberContext->currentGroup = TaskGroup::INVALID; 263 } 264 265 // Update total task count 266 int allGroupTaskCount = threadContext.taskScheduler->allGroups.Dec(); 267 MT_USED_IN_ASSERT(allGroupTaskCount); 268 MT_ASSERT(allGroupTaskCount >= 0, "Sanity check failed!"); 269 270 FiberContext* parentFiberContext = fiberContext->parentFiber; 271 if (parentFiberContext != nullptr) 272 { 273 int childrenFibersCount = parentFiberContext->childrenFibersCount.DecFetch(); 274 MT_ASSERT(childrenFibersCount >= 0, "Sanity check failed!"); 275 276 if (childrenFibersCount == 0) 277 { 278 // This is a last subtask. Restore parent task 279 MT_ASSERT(threadContext.threadId.IsEqual(ThreadId::Self()), "Thread context sanity check failed"); 280 MT_ASSERT(parentFiberContext->GetThreadContext() == nullptr, "Inactive parent should not have a valid thread context"); 281 282 // WARNING!! Thread context can changed here! Set actual current thread context. 283 parentFiberContext->SetThreadContext(&threadContext); 284 285 MT_ASSERT(parentFiberContext->GetThreadContext()->threadId.IsEqual(ThreadId::Self()), "Thread context sanity check failed"); 286 287 // All subtasks is done. 288 // Exiting and return parent fiber to scheduler 289 return parentFiberContext; 290 } else 291 { 292 // Other subtasks still exist 293 // Exiting 294 return nullptr; 295 } 296 } else 297 { 298 // Task is finished and no parent task 299 // Exiting 300 return nullptr; 301 } 302 } 303 304 MT_ASSERT(taskStatus != FiberTaskStatus::RUNNED, "Incorrect task status") 305 return nullptr; 306 } 307 308 309 void TaskScheduler::FiberMain(void* userData) 310 { 311 FiberContext& fiberContext = *(FiberContext*)(userData); 312 for(;;) 313 { 314 MT_ASSERT(fiberContext.currentTask.IsValid(), "Invalid task in fiber context"); 315 MT_ASSERT(fiberContext.GetThreadContext(), "Invalid thread context"); 316 MT_ASSERT(fiberContext.GetThreadContext()->threadId.IsEqual(ThreadId::Self()), "Thread context sanity check failed"); 317 318 #ifdef MT_INSTRUMENTED_BUILD 319 fiberContext.fiber.SetName( MT_SYSTEM_TASK_FIBER_NAME ); 320 fiberContext.GetThreadContext()->NotifyTaskExecuteStateChanged( fiberContext.currentTask.debugColor, fiberContext.currentTask.debugID, TaskExecuteState::START ); 321 #endif 322 323 fiberContext.currentTask.taskFunc( fiberContext, fiberContext.currentTask.userData ); 324 fiberContext.SetStatus(FiberTaskStatus::FINISHED); 325 326 #ifdef MT_INSTRUMENTED_BUILD 327 fiberContext.fiber.SetName( MT_SYSTEM_TASK_FIBER_NAME ); 328 fiberContext.GetThreadContext()->NotifyTaskExecuteStateChanged( fiberContext.currentTask.debugColor, fiberContext.currentTask.debugID, TaskExecuteState::STOP ); 329 #endif 330 331 Fiber::SwitchTo(fiberContext.fiber, fiberContext.GetThreadContext()->schedulerFiber); 332 } 333 334 } 335 336 337 bool TaskScheduler::TryStealTask(internal::ThreadContext& threadContext, internal::GroupedTask & task) 338 { 339 bool taskStealingDisabled = threadContext.taskScheduler->IsTaskStealingDisabled(); 340 uint32 workersCount = threadContext.taskScheduler->GetWorkersCount(); 341 342 if (workersCount <= 1 || taskStealingDisabled ) 343 { 344 return false; 345 } 346 347 uint32 victimIndex = threadContext.random.Get(); 348 349 for (uint32 attempt = 0; attempt < workersCount; attempt++) 350 { 351 uint32 index = victimIndex % workersCount; 352 if (index == threadContext.workerIndex) 353 { 354 victimIndex++; 355 index = victimIndex % workersCount; 356 } 357 358 internal::ThreadContext& victimContext = threadContext.taskScheduler->threadContext[index]; 359 if (victimContext.queue.TryPopNewest(task)) 360 { 361 return true; 362 } 363 364 victimIndex++; 365 } 366 return false; 367 } 368 369 void TaskScheduler::WorkerThreadMain( void* userData ) 370 { 371 internal::ThreadContext& context = *(internal::ThreadContext*)(userData); 372 MT_ASSERT(context.taskScheduler, "Task scheduler must be not null!"); 373 374 isWorkerThreadTLS = 1; 375 context.threadId = ThreadId::Self(); 376 377 #ifdef MT_INSTRUMENTED_BUILD 378 const char* threadNames[] = {"worker0","worker1","worker2","worker3","worker4","worker5","worker6","worker7","worker8","worker9","worker10","worker11","worker12"}; 379 if (context.workerIndex < MT_ARRAY_SIZE(threadNames)) 380 { 381 Thread::SetThreadName(threadNames[context.workerIndex]); 382 } else 383 { 384 Thread::SetThreadName("worker_thread"); 385 } 386 #endif 387 388 context.schedulerFiber.CreateFromCurrentThreadAndRun(SchedulerFiberMain, userData); 389 } 390 391 392 void TaskScheduler::SchedulerFiberWait( void* userData ) 393 { 394 WaitContext& waitContext = *(WaitContext*)(userData); 395 internal::ThreadContext& context = *waitContext.threadContext; 396 MT_ASSERT(context.taskScheduler, "Task scheduler must be not null!"); 397 MT_ASSERT(waitContext.waitCounter, "Wait counter must be not null!"); 398 399 #ifdef MT_INSTRUMENTED_BUILD 400 context.NotifyWaitStarted(); 401 context.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::START); 402 #endif 403 404 bool isTaskStealingDisabled = context.taskScheduler->IsTaskStealingDisabled(); 405 406 int64 timeOut = GetTimeMicroSeconds() + (waitContext.waitTimeMs * 1000); 407 408 SpinWait spinWait; 409 410 for(;;) 411 { 412 if ( SchedulerFiberStep(context, isTaskStealingDisabled) == false ) 413 { 414 spinWait.SpinOnce(); 415 } else 416 { 417 spinWait.Reset(); 418 } 419 420 int32 groupTaskCount = waitContext.waitCounter->Load(); 421 if (groupTaskCount == 0) 422 { 423 waitContext.exitCode = 0; 424 break; 425 } 426 427 int64 timeNow = GetTimeMicroSeconds(); 428 if (timeNow >= timeOut) 429 { 430 waitContext.exitCode = 1; 431 break; 432 } 433 } 434 435 #ifdef MT_INSTRUMENTED_BUILD 436 context.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::STOP); 437 context.NotifyWaitFinished(); 438 #endif 439 440 } 441 442 void TaskScheduler::SchedulerFiberMain( void* userData ) 443 { 444 internal::ThreadContext& context = *(internal::ThreadContext*)(userData); 445 MT_ASSERT(context.taskScheduler, "Task scheduler must be not null!"); 446 447 #ifdef MT_INSTRUMENTED_BUILD 448 context.NotifyThreadCreated(context.workerIndex); 449 #endif 450 451 int32 totalThreadsCount = context.taskScheduler->threadsCount.LoadRelaxed(); 452 context.taskScheduler->startedThreadsCount.IncFetch(); 453 454 //Simple spinlock until all threads is started and initialized 455 for(;;) 456 { 457 int32 initializedThreadsCount = context.taskScheduler->startedThreadsCount.Load(); 458 if (initializedThreadsCount == totalThreadsCount) 459 { 460 break; 461 } 462 463 // sleep some time until all other thread initialized 464 Thread::Sleep(1); 465 } 466 467 HardwareFullMemoryBarrier(); 468 469 #ifdef MT_INSTRUMENTED_BUILD 470 context.NotifyThreadStarted(context.workerIndex); 471 context.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::START); 472 #endif 473 bool isTaskStealingDisabled = context.taskScheduler->IsTaskStealingDisabled(); 474 475 while(context.state.Load() != internal::ThreadState::EXIT) 476 { 477 if ( SchedulerFiberStep(context, isTaskStealingDisabled) == false) 478 { 479 #ifdef MT_INSTRUMENTED_BUILD 480 context.NotifyThreadIdleStarted(context.workerIndex); 481 #endif 482 483 #if MT_LOW_LATENCY_EXPERIMENTAL_WAIT 484 485 SpinWait spinWait; 486 487 for(;;) 488 { 489 // Queue is empty and stealing attempt has failed. 490 // Fast Spin Wait for new tasks 491 if (spinWait.SpinOnce() >= SpinWait::YIELD_SLEEP0_THRESHOLD) 492 { 493 // Fast Spin wait for new tasks has failed. 494 // Wait for new events using events 495 context.hasNewTasksEvent.Wait(20000); 496 497 spinWait.Reset(); 498 499 #ifdef MT_INSTRUMENTED_BUILD 500 context.NotifyThreadIdleFinished(context.workerIndex); 501 #endif 502 503 break; 504 } 505 506 internal::GroupedTask task; 507 if ( context.queue.TryPopOldest(task) ) 508 { 509 #ifdef MT_INSTRUMENTED_BUILD 510 context.NotifyThreadIdleFinished(context.workerIndex); 511 #endif 512 513 SchedulerFiberProcessTask(context, task); 514 515 break; 516 } 517 518 } 519 #else 520 // Queue is empty and stealing attempt has failed. 521 // Wait for new events using events 522 context.hasNewTasksEvent.Wait(20000); 523 524 #ifdef MT_INSTRUMENTED_BUILD 525 context.NotifyThreadIdleFinished(context.workerIndex); 526 #endif 527 528 #endif 529 530 } 531 532 } // main thread loop 533 534 #ifdef MT_INSTRUMENTED_BUILD 535 context.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::STOP); 536 context.NotifyThreadStoped(context.workerIndex); 537 #endif 538 539 } 540 541 void TaskScheduler::SchedulerFiberProcessTask( internal::ThreadContext& context, internal::GroupedTask& task ) 542 { 543 #ifdef MT_INSTRUMENTED_BUILD 544 bool isNewTask = (task.awaitingFiber == nullptr); 545 #endif 546 547 // There is a new task 548 FiberContext* fiberContext = context.taskScheduler->RequestFiberContext(task); 549 MT_ASSERT(fiberContext, "Can't get execution context from pool"); 550 MT_ASSERT(fiberContext->currentTask.IsValid(), "Sanity check failed"); 551 MT_ASSERT(fiberContext->stackRequirements == task.desc.stackRequirements, "Sanity check failed"); 552 553 while(fiberContext) 554 { 555 #ifdef MT_INSTRUMENTED_BUILD 556 if (isNewTask) 557 { 558 //TODO: 559 isNewTask = false; 560 } 561 #endif 562 // prevent invalid fiber resume from child tasks, before ExecuteTask is done 563 fiberContext->childrenFibersCount.IncFetch(); 564 565 FiberContext* parentFiber = ExecuteTask(context, fiberContext); 566 567 FiberTaskStatus::Type taskStatus = fiberContext->GetStatus(); 568 569 //release guard 570 int childrenFibersCount = fiberContext->childrenFibersCount.DecFetch(); 571 572 // Can drop fiber context - task is finished 573 if (taskStatus == FiberTaskStatus::FINISHED) 574 { 575 MT_ASSERT( childrenFibersCount == 0, "Sanity check failed"); 576 context.taskScheduler->ReleaseFiberContext(std::move(fiberContext)); 577 578 // If parent fiber is exist transfer flow control to parent fiber, if parent fiber is null, exit 579 fiberContext = parentFiber; 580 } else 581 { 582 MT_ASSERT( childrenFibersCount >= 0, "Sanity check failed"); 583 584 // No subtasks here and status is not finished, this mean all subtasks already finished before parent return from ExecuteTask 585 if (childrenFibersCount == 0) 586 { 587 MT_ASSERT(parentFiber == nullptr, "Sanity check failed"); 588 } else 589 { 590 // If subtasks still exist, drop current task execution. task will be resumed when last subtask finished 591 break; 592 } 593 594 // If task is yielded execution, get another task from queue. 595 if (taskStatus == FiberTaskStatus::YIELDED) 596 { 597 // Task is yielded, add to tasks queue 598 ArrayView<internal::GroupedTask> buffer(context.descBuffer, 1); 599 ArrayView<internal::TaskBucket> buckets( MT_ALLOCATE_ON_STACK(sizeof(internal::TaskBucket)), 1 ); 600 601 FiberContext* yieldedTask = fiberContext; 602 StaticVector<FiberContext*, 1> yieldedTasksQueue(1, yieldedTask); 603 internal::DistibuteDescriptions( TaskGroup(TaskGroup::ASSIGN_FROM_CONTEXT), yieldedTasksQueue.Begin(), buffer, buckets ); 604 605 // add yielded task to scheduler 606 context.taskScheduler->RunTasksImpl(buckets, nullptr, true); 607 608 // ATENTION! yielded task can be already completed at this point 609 610 break; 611 } 612 } 613 } //while(fiberContext) 614 } 615 616 bool TaskScheduler::SchedulerFiberStep( internal::ThreadContext& context, bool disableTaskStealing) 617 { 618 internal::GroupedTask task; 619 if ( context.queue.TryPopOldest(task) || (disableTaskStealing == false && TryStealTask(context, task) ) ) 620 { 621 SchedulerFiberProcessTask(context, task); 622 return true; 623 } 624 625 return false; 626 } 627 628 void TaskScheduler::RunTasksImpl(ArrayView<internal::TaskBucket>& buckets, FiberContext * parentFiber, bool restoredFromAwaitState) 629 { 630 631 #if MT_LOW_LATENCY_EXPERIMENTAL_WAIT 632 // Early wakeup worker threads (worker thread spin wait for some time before sleep) 633 int32 roundRobinIndex = roundRobinThreadIndex.LoadRelaxed(); 634 for (size_t i = 0; i < buckets.Size(); ++i) 635 { 636 int bucketIndex = ((roundRobinIndex + i) % threadsCount.LoadRelaxed()); 637 internal::ThreadContext & context = threadContext[bucketIndex]; 638 context.hasNewTasksEvent.Signal(); 639 } 640 #endif 641 642 643 // This storage is necessary to calculate how many tasks we add to different groups 644 int newTaskCountInGroup[TaskGroup::MT_MAX_GROUPS_COUNT]; 645 646 // Default value is 0 647 memset(&newTaskCountInGroup[0], 0, MT_ARRAY_SIZE(newTaskCountInGroup)); 648 649 // Set parent fiber pointer 650 // Calculate the number of tasks per group 651 // Calculate total number of tasks 652 size_t count = 0; 653 for (size_t i = 0; i < buckets.Size(); ++i) 654 { 655 internal::TaskBucket& bucket = buckets[i]; 656 for (size_t taskIndex = 0; taskIndex < bucket.count; taskIndex++) 657 { 658 internal::GroupedTask & task = bucket.tasks[taskIndex]; 659 660 task.parentFiber = parentFiber; 661 662 int idx = task.group.GetValidIndex(); 663 MT_ASSERT(idx >= 0 && idx < TaskGroup::MT_MAX_GROUPS_COUNT, "Invalid index"); 664 newTaskCountInGroup[idx]++; 665 } 666 667 count += bucket.count; 668 } 669 670 // Increments child fibers count on parent fiber 671 if (parentFiber) 672 { 673 parentFiber->childrenFibersCount.AddFetch((int)count); 674 } 675 676 if (restoredFromAwaitState == false) 677 { 678 // Increase the number of active tasks in the group using data from temporary storage 679 for (size_t i = 0; i < TaskGroup::MT_MAX_GROUPS_COUNT; i++) 680 { 681 int groupNewTaskCount = newTaskCountInGroup[i]; 682 if (groupNewTaskCount > 0) 683 { 684 groupStats[i].Add((uint32)groupNewTaskCount); 685 } 686 } 687 688 // Increments all task in progress counter 689 allGroups.Add((uint32)count); 690 } else 691 { 692 // If task's restored from await state, counters already in correct state 693 } 694 695 // Add to thread queue 696 for (size_t i = 0; i < buckets.Size(); ++i) 697 { 698 int bucketIndex = roundRobinThreadIndex.IncFetch() % threadsCount.LoadRelaxed(); 699 internal::ThreadContext & context = threadContext[bucketIndex]; 700 701 internal::TaskBucket& bucket = buckets[i]; 702 703 for(;;) 704 { 705 MT_ASSERT(bucket.count < (internal::TASK_BUFFER_CAPACITY - 1), "Sanity check failed. Too many tasks per one bucket."); 706 707 bool res = context.queue.Add(bucket.tasks, bucket.count); 708 if (res == true) 709 { 710 break; 711 } 712 713 //Can't add new tasks onto the queue. Look like the job system is overloaded. Wait some time and try again. 714 //TODO: implement waiting until workers done using events. 715 Thread::Sleep(10); 716 } 717 718 context.hasNewTasksEvent.Signal(); 719 } 720 } 721 722 void TaskScheduler::RunAsync(TaskGroup group, const TaskHandle* taskHandleArray, uint32 taskHandleCount) 723 { 724 MT_ASSERT(!IsWorkerThread(), "Can't use RunAsync inside Task. Use FiberContext.RunAsync() instead."); 725 726 ArrayView<internal::GroupedTask> buffer(MT_ALLOCATE_ON_STACK(sizeof(internal::GroupedTask) * taskHandleCount), taskHandleCount); 727 728 uint32 bucketCount = MT::Min((uint32)GetWorkersCount(), taskHandleCount); 729 ArrayView<internal::TaskBucket> buckets(MT_ALLOCATE_ON_STACK(sizeof(internal::TaskBucket) * bucketCount), bucketCount); 730 731 internal::DistibuteDescriptions(group, taskHandleArray, buffer, buckets); 732 RunTasksImpl(buckets, nullptr, false); 733 } 734 735 bool TaskScheduler::WaitGroup(TaskGroup group, uint32 milliseconds) 736 { 737 MT_VERIFY(IsWorkerThread() == false, "Can't use WaitGroup inside Task. Use FiberContext.WaitGroupAndYield() instead.", return false); 738 739 TaskScheduler::TaskGroupDescription& groupDesc = GetGroupDesc(group); 740 741 // Early exit if not tasks in group 742 int32 taskCount = groupDesc.GetTaskCount(); 743 if (taskCount == 0) 744 { 745 return true; 746 } 747 748 size_t bytesCountForDescBuffer = internal::ThreadContext::GetMemoryRequrementInBytesForDescBuffer(); 749 void* descBuffer = MT_ALLOCATE_ON_STACK(bytesCountForDescBuffer); 750 751 internal::ThreadContext context(descBuffer); 752 context.taskScheduler = this; 753 context.SetThreadIndex(0xFFFFFFFF); 754 context.threadId = ThreadId::Self(); 755 756 WaitContext waitContext; 757 waitContext.threadContext = &context; 758 waitContext.waitCounter = groupDesc.GetWaitCounter(); 759 waitContext.waitTimeMs = milliseconds; 760 waitContext.exitCode = 0; 761 762 isWorkerThreadTLS = 1; 763 764 context.schedulerFiber.CreateFromCurrentThreadAndRun(SchedulerFiberWait, &waitContext); 765 766 isWorkerThreadTLS = 0; 767 768 #ifdef MT_INSTRUMENTED_BUILD 769 context.NotifyThreadAssignedToFiber(); 770 #endif 771 772 return (waitContext.exitCode == 0); 773 } 774 775 bool TaskScheduler::WaitAll(uint32 milliseconds) 776 { 777 MT_VERIFY(IsWorkerThread() == false, "Can't use WaitAll inside Task.", return false); 778 779 // Early exit if not tasks in group 780 int32 taskCount = allGroups.GetTaskCount(); 781 if (taskCount == 0) 782 { 783 return true; 784 } 785 786 size_t bytesCountForDescBuffer = internal::ThreadContext::GetMemoryRequrementInBytesForDescBuffer(); 787 void* descBuffer = MT_ALLOCATE_ON_STACK(bytesCountForDescBuffer); 788 789 internal::ThreadContext context(descBuffer); 790 context.taskScheduler = this; 791 context.SetThreadIndex(0xFFFFFFFF); 792 context.threadId = ThreadId::Self(); 793 794 WaitContext waitContext; 795 waitContext.threadContext = &context; 796 waitContext.waitCounter = allGroups.GetWaitCounter(); 797 waitContext.waitTimeMs = milliseconds; 798 waitContext.exitCode = 0; 799 800 isWorkerThreadTLS = 1; 801 802 context.schedulerFiber.CreateFromCurrentThreadAndRun(SchedulerFiberWait, &waitContext); 803 804 isWorkerThreadTLS = 0; 805 806 #ifdef MT_INSTRUMENTED_BUILD 807 context.NotifyThreadAssignedToFiber(); 808 #endif 809 810 return (waitContext.exitCode == 0); 811 } 812 813 bool TaskScheduler::IsTaskStealingDisabled() const 814 { 815 if (threadsCount.LoadRelaxed() <= 1) 816 { 817 return true; 818 } 819 820 return taskStealingDisabled; 821 } 822 823 int32 TaskScheduler::GetWorkersCount() const 824 { 825 return threadsCount.LoadRelaxed(); 826 } 827 828 829 bool TaskScheduler::IsWorkerThread() const 830 { 831 return (isWorkerThreadTLS != 0); 832 } 833 834 TaskGroup TaskScheduler::CreateGroup() 835 { 836 MT_ASSERT(IsWorkerThread() == false, "Can't use CreateGroup inside Task."); 837 838 TaskGroup group; 839 if (!availableGroups.TryPop(group)) 840 { 841 MT_REPORT_ASSERT("Group pool is empty"); 842 } 843 844 int idx = group.GetValidIndex(); 845 MT_USED_IN_ASSERT(idx); 846 MT_ASSERT(groupStats[idx].GetDebugIsFree() == true, "Bad logic!"); 847 #if MT_GROUP_DEBUG 848 groupStats[idx].SetDebugIsFree(false); 849 #endif 850 851 return group; 852 } 853 854 void TaskScheduler::ReleaseGroup(TaskGroup group) 855 { 856 MT_ASSERT(IsWorkerThread() == false, "Can't use ReleaseGroup inside Task."); 857 MT_ASSERT(group.IsValid(), "Invalid group ID"); 858 859 int idx = group.GetValidIndex(); 860 MT_USED_IN_ASSERT(idx); 861 MT_ASSERT(groupStats[idx].GetDebugIsFree() == false, "Group already released"); 862 #if MT_GROUP_DEBUG 863 groupStats[idx].SetDebugIsFree(true); 864 #endif 865 866 bool res = availableGroups.TryPush(std::move(group)); 867 MT_USED_IN_ASSERT(res); 868 MT_ASSERT(res, "Can't return group to pool"); 869 } 870 871 TaskScheduler::TaskGroupDescription& TaskScheduler::GetGroupDesc(TaskGroup group) 872 { 873 MT_ASSERT(group.IsValid(), "Invalid group ID"); 874 875 int idx = group.GetValidIndex(); 876 TaskScheduler::TaskGroupDescription & groupDesc = groupStats[idx]; 877 878 MT_ASSERT(groupDesc.GetDebugIsFree() == false, "Invalid group"); 879 return groupDesc; 880 } 881 882 883 #ifdef MT_INSTRUMENTED_BUILD 884 885 void TaskScheduler::NotifyFibersCreated(uint32 fibersCount) 886 { 887 if (IProfilerEventListener* eventListener = GetProfilerEventListener()) 888 { 889 eventListener->OnFibersCreated(fibersCount); 890 } 891 } 892 893 void TaskScheduler::NotifyThreadsCreated(uint32 threadsCount) 894 { 895 if (IProfilerEventListener* eventListener = GetProfilerEventListener()) 896 { 897 eventListener->OnThreadsCreated(threadsCount); 898 } 899 } 900 901 902 #endif 903 904 } 905 906 907