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 <string.h> // for memset
25 
26 namespace MT
27 {
28 
29 #ifdef MT_INSTRUMENTED_BUILD
30 	TaskScheduler::TaskScheduler(uint32 workerThreadsCount, WorkerThreadParams* workerParameters, IProfilerEventListener* listener)
31 #else
32 	TaskScheduler::TaskScheduler(uint32 workerThreadsCount, WorkerThreadParams* workerParameters)
33 #endif
34 		: roundRobinThreadIndex(0)
35 		, startedThreadsCount(0)
36 	{
37 
38 #ifdef MT_INSTRUMENTED_BUILD
39 		profilerEventListener = listener;
40 #endif
41 
42 		if (workerThreadsCount != 0)
43 		{
44 			threadsCount.StoreRelaxed( MT::Clamp(workerThreadsCount, (uint32)1, (uint32)MT_MAX_THREAD_COUNT) );
45 		} else
46 		{
47 			//query number of processor
48 			threadsCount.StoreRelaxed( (uint32)MT::Clamp(Thread::GetNumberOfHardwareThreads() - 1, 1, (int)MT_MAX_THREAD_COUNT) );
49 		}
50 
51 		// create fiber pool (fibers with standard stack size)
52 		for (uint32 i = 0; i < MT_MAX_STANDART_FIBERS_COUNT; i++)
53 		{
54 			FiberContext& context = standartFiberContexts[i];
55 			context.fiber.Create(MT_STANDART_FIBER_STACK_SIZE, FiberMain, &context);
56 			bool res = standartFibersAvailable.TryPush( &context );
57 			MT_USED_IN_ASSERT(res);
58 			MT_ASSERT(res == true, "Can't add fiber to storage");
59 		}
60 
61 		// create fiber pool (fibers with extended stack size)
62 		for (uint32 i = 0; i < MT_MAX_EXTENDED_FIBERS_COUNT; i++)
63 		{
64 			FiberContext& context = extendedFiberContexts[i];
65 			context.fiber.Create(MT_EXTENDED_FIBER_STACK_SIZE, FiberMain, &context);
66 			bool res = extendedFibersAvailable.TryPush( &context );
67 			MT_USED_IN_ASSERT(res);
68 			MT_ASSERT(res == true, "Can't add fiber to storage");
69 		}
70 
71 
72 		for (int16 i = 0; i < TaskGroup::MT_MAX_GROUPS_COUNT; i++)
73 		{
74 			if (i != TaskGroup::DEFAULT)
75 			{
76 				bool res = availableGroups.TryPush( TaskGroup(i) );
77 				MT_USED_IN_ASSERT(res);
78 				MT_ASSERT(res == true, "Can't add group to storage");
79 			}
80 		}
81 
82 #if MT_GROUP_DEBUG
83 		groupStats[TaskGroup::DEFAULT].SetDebugIsFree(false);
84 #endif
85 
86 		// create worker thread pool
87 		int32 totalThreadsCount = GetWorkersCount();
88 		for (int32 i = 0; i < totalThreadsCount; i++)
89 		{
90 			threadContext[i].SetThreadIndex(i);
91 			threadContext[i].taskScheduler = this;
92 
93 			uint32 threadCore = i;
94 			ThreadPriority::Type priority = ThreadPriority::DEFAULT;
95 			if (workerParameters != nullptr)
96 			{
97 				const WorkerThreadParams& params = workerParameters[i];
98 
99 				threadCore = params.core;
100 				priority = params.priority;
101 			}
102 
103 			threadContext[i].thread.Start( MT_SCHEDULER_STACK_SIZE, WorkerThreadMain, &threadContext[i], threadCore, priority);
104 		}
105 	}
106 
107 
108 	TaskScheduler::~TaskScheduler()
109 	{
110 		int32 totalThreadsCount = GetWorkersCount();
111 		for (int32 i = 0; i < totalThreadsCount; i++)
112 		{
113 			threadContext[i].state.Store(internal::ThreadState::EXIT);
114 			threadContext[i].hasNewTasksEvent.Signal();
115 		}
116 
117 		for (int32 i = 0; i < totalThreadsCount; i++)
118 		{
119 			threadContext[i].thread.Join();
120 		}
121 	}
122 
123 	FiberContext* TaskScheduler::RequestFiberContext(internal::GroupedTask& task)
124 	{
125 		FiberContext *fiberContext = task.awaitingFiber;
126 		if (fiberContext)
127 		{
128 			task.awaitingFiber = nullptr;
129 			return fiberContext;
130 		}
131 
132 		MT::StackRequirements::Type stackRequirements = task.desc.stackRequirements;
133 
134 		fiberContext = nullptr;
135 		bool res = false;
136 		MT_USED_IN_ASSERT(res);
137 		switch(stackRequirements)
138 		{
139 		case MT::StackRequirements::STANDARD:
140 			res = standartFibersAvailable.TryPop(fiberContext);
141 			MT_ASSERT(res, "Can't get more standard fibers!");
142 			break;
143 		case MT::StackRequirements::EXTENDED:
144 			res = extendedFibersAvailable.TryPop(fiberContext);
145 			MT_ASSERT(res, "Can't get more extended fibers!");
146 			break;
147 		default:
148 			MT_REPORT_ASSERT("Unknown stack requrements");
149 		}
150 
151 		MT_ASSERT(fiberContext != nullptr, "Can't get more fibers. Too many tasks in flight simultaneously?");
152 
153 		fiberContext->currentTask = task.desc;
154 		fiberContext->currentGroup = task.group;
155 		fiberContext->parentFiber = task.parentFiber;
156 		fiberContext->stackRequirements = stackRequirements;
157 		return fiberContext;
158 	}
159 
160 	void TaskScheduler::ReleaseFiberContext(FiberContext*&& fiberContext)
161 	{
162 		MT_ASSERT(fiberContext, "Can't release nullptr Fiber. fiberContext is nullptr");
163 
164 		MT::StackRequirements::Type stackRequirements = fiberContext->stackRequirements;
165 		fiberContext->Reset();
166 
167 		MT_ASSERT(fiberContext != nullptr, "Fiber context can't be nullptr");
168 
169 		bool res = false;
170 		MT_USED_IN_ASSERT(res);
171 		switch(stackRequirements)
172 		{
173 		case MT::StackRequirements::STANDARD:
174 			res = standartFibersAvailable.TryPush(std::move(fiberContext));
175 			break;
176 		case MT::StackRequirements::EXTENDED:
177 			res = extendedFibersAvailable.TryPush(std::move(fiberContext));
178 			break;
179 		default:
180 			MT_REPORT_ASSERT("Unknown stack requrements");
181 		}
182 
183 		MT_USED_IN_ASSERT(res);
184 		MT_ASSERT(res != false, "Can't return fiber to storage");
185 	}
186 
187 	FiberContext* TaskScheduler::ExecuteTask(internal::ThreadContext& threadContext, FiberContext* fiberContext)
188 	{
189 		MT_ASSERT(threadContext.thread.IsCurrentThread(), "Thread context sanity check failed");
190 
191 		MT_ASSERT(fiberContext, "Invalid fiber context");
192 		MT_ASSERT(fiberContext->currentTask.IsValid(), "Invalid task");
193 
194 		// Set actual thread context to fiber
195 		fiberContext->SetThreadContext(&threadContext);
196 
197 		// Update task status
198 		fiberContext->SetStatus(FiberTaskStatus::RUNNED);
199 
200 		MT_ASSERT(fiberContext->GetThreadContext()->thread.IsCurrentThread(), "Thread context sanity check failed");
201 
202 		const void* poolUserData = fiberContext->currentTask.userData;
203 		TPoolTaskDestroy poolDestroyFunc = fiberContext->currentTask.poolDestroyFunc;
204 
205 #ifdef MT_INSTRUMENTED_BUILD
206 		//threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::SUSPEND);
207 		threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::STOP);
208 #endif
209 
210 		// Run current task code
211 		Fiber::SwitchTo(threadContext.schedulerFiber, fiberContext->fiber);
212 
213 #ifdef MT_INSTRUMENTED_BUILD
214 		//threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::RESUME);
215 		threadContext.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::START);
216 #endif
217 
218 		// If task was done
219 		FiberTaskStatus::Type taskStatus = fiberContext->GetStatus();
220 		if (taskStatus == FiberTaskStatus::FINISHED)
221 		{
222 			//destroy task (call dtor) for "fire and forget" type of task from TaskPool
223 			if (poolDestroyFunc != nullptr)
224 			{
225 				poolDestroyFunc(poolUserData);
226 			}
227 
228 			TaskGroup taskGroup = fiberContext->currentGroup;
229 
230 			TaskScheduler::TaskGroupDescription  & groupDesc = threadContext.taskScheduler->GetGroupDesc(taskGroup);
231 
232 			// Update group status
233 			int groupTaskCount = groupDesc.Dec();
234 			MT_ASSERT(groupTaskCount >= 0, "Sanity check failed!");
235 			if (groupTaskCount == 0)
236 			{
237 				// Signal pending threads that group work is finished. Group can be destroyed after this call.
238 				groupDesc.Signal();
239 
240 				fiberContext->currentGroup = TaskGroup::INVALID;
241 			}
242 
243 			// Update total task count
244 			int allGroupTaskCount = threadContext.taskScheduler->allGroups.Dec();
245 			MT_ASSERT(allGroupTaskCount >= 0, "Sanity check failed!");
246 			if (allGroupTaskCount == 0)
247 			{
248 				// Notify all tasks in all group finished
249 				threadContext.taskScheduler->allGroups.Signal();
250 			}
251 
252 			FiberContext* parentFiberContext = fiberContext->parentFiber;
253 			if (parentFiberContext != nullptr)
254 			{
255 				int childrenFibersCount = parentFiberContext->childrenFibersCount.DecFetch();
256 				MT_ASSERT(childrenFibersCount >= 0, "Sanity check failed!");
257 
258 				if (childrenFibersCount == 0)
259 				{
260 					// This is a last subtask. Restore parent task
261 					MT_ASSERT(threadContext.thread.IsCurrentThread(), "Thread context sanity check failed");
262 					MT_ASSERT(parentFiberContext->GetThreadContext() == nullptr, "Inactive parent should not have a valid thread context");
263 
264 					// WARNING!! Thread context can changed here! Set actual current thread context.
265 					parentFiberContext->SetThreadContext(&threadContext);
266 
267 					MT_ASSERT(parentFiberContext->GetThreadContext()->thread.IsCurrentThread(), "Thread context sanity check failed");
268 
269 					// All subtasks is done.
270 					// Exiting and return parent fiber to scheduler
271 					return parentFiberContext;
272 				} else
273 				{
274 					// Other subtasks still exist
275 					// Exiting
276 					return nullptr;
277 				}
278 			} else
279 			{
280 				// Task is finished and no parent task
281 				// Exiting
282 				return nullptr;
283 			}
284 		}
285 
286 		MT_ASSERT(taskStatus != FiberTaskStatus::RUNNED, "Incorrect task status")
287 		return nullptr;
288 	}
289 
290 
291 	void TaskScheduler::FiberMain(void* userData)
292 	{
293 		FiberContext& fiberContext = *(FiberContext*)(userData);
294 		for(;;)
295 		{
296 			MT_ASSERT(fiberContext.currentTask.IsValid(), "Invalid task in fiber context");
297 			MT_ASSERT(fiberContext.GetThreadContext(), "Invalid thread context");
298 			MT_ASSERT(fiberContext.GetThreadContext()->thread.IsCurrentThread(), "Thread context sanity check failed");
299 
300 #ifdef MT_INSTRUMENTED_BUILD
301 			fiberContext.fiber.SetName( MT_SYSTEM_TASK_FIBER_NAME );
302 			fiberContext.GetThreadContext()->NotifyTaskExecuteStateChanged( fiberContext.currentTask.debugColor, fiberContext.currentTask.debugID, TaskExecuteState::START );
303 #endif
304 
305 			fiberContext.currentTask.taskFunc( fiberContext, fiberContext.currentTask.userData );
306 			fiberContext.SetStatus(FiberTaskStatus::FINISHED);
307 
308 #ifdef MT_INSTRUMENTED_BUILD
309 			fiberContext.fiber.SetName( MT_SYSTEM_TASK_FIBER_NAME );
310 			fiberContext.GetThreadContext()->NotifyTaskExecuteStateChanged( fiberContext.currentTask.debugColor, fiberContext.currentTask.debugID, TaskExecuteState::STOP );
311 #endif
312 
313 			Fiber::SwitchTo(fiberContext.fiber, fiberContext.GetThreadContext()->schedulerFiber);
314 		}
315 
316 	}
317 
318 
319 	bool TaskScheduler::TryStealTask(internal::ThreadContext& threadContext, internal::GroupedTask & task, uint32 workersCount)
320 	{
321 		if (workersCount <= 1)
322 		{
323 			return false;
324 		}
325 
326 		uint32 victimIndex = threadContext.random.Get();
327 
328 		for (uint32 attempt = 0; attempt < workersCount; attempt++)
329 		{
330 			uint32 index = victimIndex % workersCount;
331 			if (index == threadContext.workerIndex)
332 			{
333 				victimIndex++;
334 				index = victimIndex % workersCount;
335 			}
336 
337 			internal::ThreadContext& victimContext = threadContext.taskScheduler->threadContext[index];
338 			if (victimContext.queue.TryPopNewest(task))
339 			{
340 				return true;
341 			}
342 
343 			victimIndex++;
344 		}
345 		return false;
346 	}
347 
348 
349 	void TaskScheduler::WorkerThreadMain( void* userData )
350 	{
351 		internal::ThreadContext& context = *(internal::ThreadContext*)(userData);
352 		MT_ASSERT(context.taskScheduler, "Task scheduler must be not null!");
353 
354 #ifdef MT_INSTRUMENTED_BUILD
355 		const char* threadNames[] = {"worker0","worker1","worker2","worker3","worker4","worker5","worker6","worker7","worker8","worker9","worker10","worker11","worker12"};
356 		if (context.workerIndex < MT_ARRAY_SIZE(threadNames))
357 		{
358 			Thread::SetThreadName(threadNames[context.workerIndex]);
359 		} else
360 		{
361 			Thread::SetThreadName("worker_thread");
362 		}
363 #endif
364 
365 		context.schedulerFiber.CreateFromCurrentThreadAndRun(SchedulerFiberMain, userData);
366 	}
367 
368 
369 	void TaskScheduler::SchedulerFiberMain( void* userData )
370 	{
371 		internal::ThreadContext& context = *(internal::ThreadContext*)(userData);
372 		MT_ASSERT(context.taskScheduler, "Task scheduler must be not null!");
373 
374 #ifdef MT_INSTRUMENTED_BUILD
375 		context.NotifyThreadCreate(context.workerIndex);
376 #endif
377 
378 		uint32 workersCount = context.taskScheduler->GetWorkersCount();
379 		int32 totalThreadsCount = context.taskScheduler->threadsCount.LoadRelaxed();
380 
381 		context.taskScheduler->startedThreadsCount.IncFetch();
382 
383 		//Simple spinlock until all threads is started and initialized
384 		for(;;)
385 		{
386 			int32 initializedThreadsCount = context.taskScheduler->startedThreadsCount.Load();
387 			if (initializedThreadsCount == totalThreadsCount)
388 			{
389 				break;
390 			}
391 
392 			// sleep some time until all other thread initialized
393 			Thread::Sleep(1);
394 		}
395 
396 		HardwareFullMemoryBarrier();
397 
398 #ifdef MT_INSTRUMENTED_BUILD
399 		context.NotifyThreadStart(context.workerIndex);
400 		context.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::START);
401 #endif
402 
403 		while(context.state.Load() != internal::ThreadState::EXIT)
404 		{
405 			internal::GroupedTask task;
406 			if (context.queue.TryPopOldest(task) || TryStealTask(context, task, workersCount) )
407 			{
408 #ifdef MT_INSTRUMENTED_BUILD
409 				bool isNewTask = (task.awaitingFiber == nullptr);
410 #endif
411 
412 				// There is a new task
413 				FiberContext* fiberContext = context.taskScheduler->RequestFiberContext(task);
414 				MT_ASSERT(fiberContext, "Can't get execution context from pool");
415 				MT_ASSERT(fiberContext->currentTask.IsValid(), "Sanity check failed");
416 				MT_ASSERT(fiberContext->stackRequirements == task.desc.stackRequirements, "Sanity check failed");
417 
418 				while(fiberContext)
419 				{
420 #ifdef MT_INSTRUMENTED_BUILD
421 					if (isNewTask)
422 					{
423 						//TODO:
424 						isNewTask = false;
425 					}
426 #endif
427 					// prevent invalid fiber resume from child tasks, before ExecuteTask is done
428 					fiberContext->childrenFibersCount.IncFetch();
429 
430 					FiberContext* parentFiber = ExecuteTask(context, fiberContext);
431 
432 					FiberTaskStatus::Type taskStatus = fiberContext->GetStatus();
433 
434 					//release guard
435 					int childrenFibersCount = fiberContext->childrenFibersCount.DecFetch();
436 
437 					// Can drop fiber context - task is finished
438 					if (taskStatus == FiberTaskStatus::FINISHED)
439 					{
440 						MT_ASSERT( childrenFibersCount == 0, "Sanity check failed");
441 						context.taskScheduler->ReleaseFiberContext(std::move(fiberContext));
442 
443 						// If parent fiber is exist transfer flow control to parent fiber, if parent fiber is null, exit
444 						fiberContext = parentFiber;
445 					} else
446 					{
447 						MT_ASSERT( childrenFibersCount >= 0, "Sanity check failed");
448 
449 						// No subtasks here and status is not finished, this mean all subtasks already finished before parent return from ExecuteTask
450 						if (childrenFibersCount == 0)
451 						{
452 							MT_ASSERT(parentFiber == nullptr, "Sanity check failed");
453 						} else
454 						{
455 							// If subtasks still exist, drop current task execution. task will be resumed when last subtask finished
456 							break;
457 						}
458 
459 						// If task is in await state drop execution. task will be resumed when RestoreAwaitingTasks called
460 						if (taskStatus == FiberTaskStatus::AWAITING_GROUP)
461 						{
462 							break;
463 						}
464 					}
465 				} //while(fiberContext)
466 
467 			} else
468 			{
469 #ifdef MT_INSTRUMENTED_BUILD
470 				context.NotifyThreadIdleBegin(context.workerIndex);
471 #endif
472 
473 				// Queue if empty and stealing attempt failed
474 				// Wait for new events
475 				context.hasNewTasksEvent.Wait(2000);
476 
477 #ifdef MT_INSTRUMENTED_BUILD
478 				context.NotifyThreadIdleEnd(context.workerIndex);
479 #endif
480 
481 			}
482 
483 		} // main thread loop
484 
485 #ifdef MT_INSTRUMENTED_BUILD
486 		context.NotifyTaskExecuteStateChanged( MT_SYSTEM_TASK_COLOR, MT_SYSTEM_TASK_NAME, TaskExecuteState::STOP);
487 		context.NotifyThreadStop(context.workerIndex);
488 #endif
489 
490 	}
491 
492 	void TaskScheduler::RunTasksImpl(ArrayView<internal::TaskBucket>& buckets, FiberContext * parentFiber, bool restoredFromAwaitState)
493 	{
494 		// This storage is necessary to calculate how many tasks we add to different groups
495 		int newTaskCountInGroup[TaskGroup::MT_MAX_GROUPS_COUNT];
496 
497 		// Default value is 0
498 		memset(&newTaskCountInGroup[0], 0, sizeof(newTaskCountInGroup));
499 
500 		// Set parent fiber pointer
501 		// Calculate the number of tasks per group
502 		// Calculate total number of tasks
503 		size_t count = 0;
504 		for (size_t i = 0; i < buckets.Size(); ++i)
505 		{
506 			internal::TaskBucket& bucket = buckets[i];
507 			for (size_t taskIndex = 0; taskIndex < bucket.count; taskIndex++)
508 			{
509 				internal::GroupedTask & task = bucket.tasks[taskIndex];
510 
511 				task.parentFiber = parentFiber;
512 
513 				int idx = task.group.GetValidIndex();
514 				MT_ASSERT(idx >= 0 && idx < TaskGroup::MT_MAX_GROUPS_COUNT, "Invalid index");
515 				newTaskCountInGroup[idx]++;
516 			}
517 
518 			count += bucket.count;
519 		}
520 
521 		// Increments child fibers count on parent fiber
522 		if (parentFiber)
523 		{
524 			parentFiber->childrenFibersCount.AddFetch((int)count);
525 		}
526 
527 		if (restoredFromAwaitState == false)
528 		{
529 			// Increase the number of active tasks in the group using data from temporary storage
530 			for (size_t i = 0; i < TaskGroup::MT_MAX_GROUPS_COUNT; i++)
531 			{
532 				int groupNewTaskCount = newTaskCountInGroup[i];
533 				if (groupNewTaskCount > 0)
534 				{
535 					groupStats[i].Reset();
536 					groupStats[i].Add((uint32)groupNewTaskCount);
537 				}
538 			}
539 
540 			// Increments all task in progress counter
541 			allGroups.Reset();
542 			allGroups.Add((uint32)count);
543 		} else
544 		{
545 			// If task's restored from await state, counters already in correct state
546 		}
547 
548 		// Add to thread queue
549 		for (size_t i = 0; i < buckets.Size(); ++i)
550 		{
551 			int bucketIndex = roundRobinThreadIndex.IncFetch() % threadsCount.LoadRelaxed();
552 			internal::ThreadContext & context = threadContext[bucketIndex];
553 
554 			internal::TaskBucket& bucket = buckets[i];
555 
556 			for(;;)
557 			{
558 				bool res = context.queue.Add(bucket.tasks, bucket.count);
559 				if (res == true)
560 				{
561 					break;
562 				}
563 
564 				//Can't add new tasks onto the queue. Look like the job system is overloaded. Wait some time and try again.
565 				//TODO: implement waiting until workers done using events.
566 				Thread::Sleep(10);
567 			}
568 
569 			context.hasNewTasksEvent.Signal();
570 		}
571 	}
572 
573 	void TaskScheduler::RunAsync(TaskGroup group, const TaskHandle* taskHandleArray, uint32 taskHandleCount)
574 	{
575 		MT_ASSERT(!IsWorkerThread(), "Can't use RunAsync inside Task. Use FiberContext.RunAsync() instead.");
576 
577 		ArrayView<internal::GroupedTask> buffer(MT_ALLOCATE_ON_STACK(sizeof(internal::GroupedTask) * taskHandleCount), taskHandleCount);
578 
579 		uint32 bucketCount = MT::Min((uint32)GetWorkersCount(), taskHandleCount);
580 		ArrayView<internal::TaskBucket> buckets(MT_ALLOCATE_ON_STACK(sizeof(internal::TaskBucket) * bucketCount), bucketCount);
581 
582 		internal::DistibuteDescriptions(group, taskHandleArray, buffer, buckets);
583 		RunTasksImpl(buckets, nullptr, false);
584 	}
585 
586 	bool TaskScheduler::WaitGroup(TaskGroup group, uint32 milliseconds)
587 	{
588 		MT_VERIFY(IsWorkerThread() == false, "Can't use WaitGroup inside Task. Use FiberContext.WaitGroupAndYield() instead.", return false);
589 
590 		TaskScheduler::TaskGroupDescription & groupDesc = GetGroupDesc(group);
591 
592 		return groupDesc.Wait(milliseconds);
593 	}
594 
595 	bool TaskScheduler::WaitAll(uint32 milliseconds)
596 	{
597 		MT_VERIFY(IsWorkerThread() == false, "Can't use WaitAll inside Task.", return false);
598 
599 		return allGroups.Wait(milliseconds);
600 	}
601 
602 	bool TaskScheduler::IsEmpty()
603 	{
604 		for (uint32 i = 0; i < MT_MAX_THREAD_COUNT; i++)
605 		{
606 			if (!threadContext[i].queue.IsEmpty())
607 			{
608 				return false;
609 			}
610 		}
611 		return true;
612 	}
613 
614 	int32 TaskScheduler::GetWorkersCount() const
615 	{
616 		return threadsCount.LoadRelaxed();
617 	}
618 
619 	bool TaskScheduler::IsWorkerThread() const
620 	{
621 		for (uint32 i = 0; i < MT_MAX_THREAD_COUNT; i++)
622 		{
623 			if (threadContext[i].thread.IsCurrentThread())
624 			{
625 				return true;
626 			}
627 		}
628 		return false;
629 	}
630 
631 	TaskGroup TaskScheduler::CreateGroup()
632 	{
633 		MT_ASSERT(IsWorkerThread() == false, "Can't use CreateGroup inside Task.");
634 
635 		TaskGroup group;
636 		if (!availableGroups.TryPop(group))
637 		{
638 			MT_REPORT_ASSERT("Group pool is empty");
639 		}
640 
641 		int idx = group.GetValidIndex();
642 		MT_USED_IN_ASSERT(idx);
643 		MT_ASSERT(groupStats[idx].GetDebugIsFree() == true, "Bad logic!");
644 #if MT_GROUP_DEBUG
645 		groupStats[idx].SetDebugIsFree(false);
646 #endif
647 
648 		return group;
649 	}
650 
651 	void TaskScheduler::ReleaseGroup(TaskGroup group)
652 	{
653 		MT_ASSERT(IsWorkerThread() == false, "Can't use ReleaseGroup inside Task.");
654 		MT_ASSERT(group.IsValid(), "Invalid group ID");
655 
656 		int idx = group.GetValidIndex();
657 		MT_USED_IN_ASSERT(idx);
658 		MT_ASSERT(groupStats[idx].GetDebugIsFree() == false, "Group already released");
659 #if MT_GROUP_DEBUG
660 		groupStats[idx].SetDebugIsFree(true);
661 #endif
662 
663 		bool res = availableGroups.TryPush(std::move(group));
664 		MT_USED_IN_ASSERT(res);
665 		MT_ASSERT(res, "Can't return group to pool");
666 	}
667 
668 	TaskScheduler::TaskGroupDescription & TaskScheduler::GetGroupDesc(TaskGroup group)
669 	{
670 		MT_ASSERT(group.IsValid(), "Invalid group ID");
671 
672 		int idx = group.GetValidIndex();
673 		TaskScheduler::TaskGroupDescription & groupDesc = groupStats[idx];
674 
675 		MT_ASSERT(groupDesc.GetDebugIsFree() == false, "Invalid group");
676 		return groupDesc;
677 	}
678 }
679 
680 
681