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 
25 namespace MT
26 {
27 	FiberContext::FiberContext()
28 		: threadContext(nullptr)
29 		, taskStatus(FiberTaskStatus::UNKNOWN)
30 		, childrenFibersCount(0)
31 		, parentFiber(nullptr)
32 	{
33 	}
34 
35 	void FiberContext::SetStatus(FiberTaskStatus::Type _taskStatus)
36 	{
37 		MT_ASSERT(threadContext, "Sanity check failed");
38 		MT_ASSERT(threadContext->thread.IsCurrentThread(), "You can change task status only from owner thread");
39 		taskStatus = _taskStatus;
40 	}
41 
42 	FiberTaskStatus::Type FiberContext::GetStatus() const
43 	{
44 		return taskStatus;
45 	}
46 
47 	void FiberContext::SetThreadContext(internal::ThreadContext * _threadContext)
48 	{
49 		if (_threadContext)
50 		{
51 			_threadContext->lastActiveFiberContext = this;
52 		}
53 
54 		threadContext = _threadContext;
55 	}
56 
57 	internal::ThreadContext* FiberContext::GetThreadContext()
58 	{
59 		return threadContext;
60 	}
61 
62 	void FiberContext::Reset()
63 	{
64 		MT_ASSERT(childrenFibersCount.Load() == 0, "Can't release fiber with active children fibers");
65 		currentTask = internal::TaskDesc();
66 		parentFiber = nullptr;
67 		threadContext = nullptr;
68 		stackRequirements = StackRequirements::INVALID;
69 	}
70 
71 	void FiberContext::WaitGroupAndYield(TaskGroup group)
72 	{
73 		MT_ASSERT(threadContext, "Sanity check failed!");
74 		MT_ASSERT(threadContext->taskScheduler->IsWorkerThread(), "Can't use WaitGroupAndYield outside Task. Use TaskScheduler.WaitGroup() instead.");
75 		MT_ASSERT(threadContext->thread.IsCurrentThread(), "Thread context sanity check failed");
76 
77 		MT_VERIFY(group != currentGroup, "Can't wait the same group. Deadlock detected!", return);
78 		MT_VERIFY(group.IsValid(), "Invalid group!", return);
79 
80 		TaskScheduler::TaskGroupDescription  & groupDesc = threadContext->taskScheduler->GetGroupDesc(group);
81 
82 		ConcurrentQueueLIFO<FiberContext*> & groupQueue = groupDesc.GetWaitQueue();
83 
84 		// Change status
85 		taskStatus = FiberTaskStatus::AWAITING_GROUP;
86 
87 		// Add current fiber to awaiting queue
88 		groupQueue.Push(this);
89 
90 		Fiber & schedulerFiber = threadContext->schedulerFiber;
91 
92 #ifdef MT_INSTRUMENTED_BUILD
93 		threadContext->NotifyTaskYielded(currentTask);
94 #endif
95 
96 		// Yielding, so reset thread context
97 		threadContext = nullptr;
98 
99 		//switch to scheduler
100 		Fiber::SwitchTo(fiber, schedulerFiber);
101 	}
102 
103 	void FiberContext::RunSubtasksAndYieldImpl(ArrayView<internal::TaskBucket>& buckets)
104 	{
105 		MT_ASSERT(threadContext, "Sanity check failed!");
106 		MT_ASSERT(threadContext->taskScheduler->IsWorkerThread(), "Can't use RunSubtasksAndYield outside Task. Use TaskScheduler.WaitGroup() instead.");
107 		MT_ASSERT(threadContext->thread.IsCurrentThread(), "Thread context sanity check failed");
108 
109 		// add to scheduler
110 		threadContext->taskScheduler->RunTasksImpl(buckets, this, false);
111 
112 		//
113 		MT_ASSERT(threadContext->thread.IsCurrentThread(), "Thread context sanity check failed");
114 
115 		// Change status
116 		taskStatus = FiberTaskStatus::AWAITING_CHILD;
117 
118 		Fiber & schedulerFiber = threadContext->schedulerFiber;
119 
120 #ifdef MT_INSTRUMENTED_BUILD
121 		threadContext->NotifyTaskYielded(currentTask);
122 #endif
123 
124 		// Yielding, so reset thread context
125 		threadContext = nullptr;
126 
127 		//switch to scheduler
128 		Fiber::SwitchTo(fiber, schedulerFiber);
129 	}
130 
131 
132 	void FiberContext::RunAsync(TaskGroup taskGroup, const TaskHandle* taskHandleArray, uint32 taskHandleCount)
133 	{
134 		MT_ASSERT(threadContext, "ThreadContext is nullptr");
135 		MT_ASSERT(threadContext->taskScheduler->IsWorkerThread(), "Can't use RunAsync outside Task. Use TaskScheduler.RunAsync() instead.");
136 
137 		TaskScheduler& scheduler = *(threadContext->taskScheduler);
138 
139 		ArrayView<internal::GroupedTask> buffer(threadContext->descBuffer, taskHandleCount);
140 
141 		uint32 bucketCount = MT::Min((uint32)scheduler.GetWorkersCount(), taskHandleCount);
142 		ArrayView<internal::TaskBucket>	buckets(MT_ALLOCATE_ON_STACK(sizeof(internal::TaskBucket) * bucketCount), bucketCount);
143 
144 		internal::DistibuteDescriptions(taskGroup, taskHandleArray, buffer, buckets);
145 		scheduler.RunTasksImpl(buckets, nullptr, false);
146 	}
147 
148 
149 	void FiberContext::RunSubtasksAndYield(TaskGroup taskGroup, const TaskHandle* taskHandleArray, uint32 taskHandleCount)
150 	{
151 		MT_ASSERT(threadContext, "ThreadContext is nullptr");
152 		MT_ASSERT(taskHandleCount < internal::TASK_BUFFER_CAPACITY, "Buffer overrun!");
153 
154 		TaskScheduler& scheduler = *(threadContext->taskScheduler);
155 
156 		ArrayView<internal::GroupedTask> buffer(threadContext->descBuffer, taskHandleCount);
157 
158 		uint32 bucketCount = MT::Min((uint32)scheduler.GetWorkersCount(), taskHandleCount);
159 		ArrayView<internal::TaskBucket> buckets(MT_ALLOCATE_ON_STACK(sizeof(internal::TaskBucket) * bucketCount), bucketCount);
160 
161 		internal::DistibuteDescriptions(taskGroup, taskHandleArray, buffer, buckets);
162 		RunSubtasksAndYieldImpl(buckets);
163 	}
164 
165 
166 
167 }
168