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 #pragma once
24 
25 #ifndef __MT_FIBER_DEFAULT__
26 #define __MT_FIBER_DEFAULT__
27 
28 #include "MTAtomic.h"
29 
30 namespace MT
31 {
32 
FiberGetSelf()33 	inline void* FiberGetSelf()
34 	{
35 		MW_BOOL isThreadAFiber = ::IsThreadAFiber();
36 		if  (isThreadAFiber == 0)
37 		{
38 			// GetCurrentFiber() return invalid values is current thread is not fiber.
39 			return nullptr;
40 		}
41 
42 		//This function is equal to GetCurrentFiber() macro
43 		void* pFiber = (void*)ReadTeb(MW_CURRENT_FIBER_OFFSET);
44 		return pFiber;
45 	}
46 
47 
48 	//
49 	// Fibers implementation using system fibers
50 	// Beware! Windows Fibers are wasteful use of Virtual Memory space for the stack. ( 1Mb reserved for each Fiber )
51 	//
52 	class Fiber
53 	{
54 		void* funcData;
55 		TThreadEntryPoint func;
56 
57 		void* fiber;
58 
FiberFuncInternal(void * pFiber)59 		static void __stdcall FiberFuncInternal(void* pFiber)
60 		{
61 			Fiber* self = (Fiber*)pFiber;
62 			self->func(self->funcData);
63 		}
64 
CleanUp()65 		void CleanUp()
66 		{
67 			if (fiber)
68 			{
69 				// Do not destroy fibers created using ::ConvertThreadToFiberEx
70 				if (func != nullptr)
71 				{
72 					::DeleteFiber(fiber);
73 				}
74 				else
75 				{
76 					::ConvertFiberToThread();
77 				}
78 				fiber = nullptr;
79 			}
80 		}
81 
82 	public:
83 
84 		MT_NOCOPYABLE(Fiber);
85 
Fiber()86 		Fiber()
87 			: fiber(nullptr)
88 		{
89 		}
90 
~Fiber()91 		~Fiber()
92 		{
93 			CleanUp();
94 		}
95 
96 
CreateFromCurrentThreadAndRun(TThreadEntryPoint entryPoint,void * userData)97 		void CreateFromCurrentThreadAndRun(TThreadEntryPoint entryPoint, void *userData)
98 		{
99 			MT_ASSERT(fiber == nullptr, "Fiber already created");
100 
101 			func = nullptr;
102 			funcData = nullptr;
103 
104 			void* fiberSelf = FiberGetSelf();
105 			if (fiberSelf != nullptr)
106 			{
107 				fiber = fiberSelf;
108 			} else
109 			{
110 				fiber = ::ConvertThreadToFiberEx(nullptr, MW_FIBER_FLAG_FLOAT_SWITCH);
111 				MT_ASSERT(fiber != nullptr, "Can't create fiber");
112 			}
113 
114 			entryPoint(userData);
115 
116 			CleanUp();
117 		}
118 
119 
Create(size_t stackSize,TThreadEntryPoint entryPoint,void * userData)120 		void Create(size_t stackSize, TThreadEntryPoint entryPoint, void* userData)
121 		{
122 			MT_ASSERT(fiber == nullptr, "Fiber already created");
123 
124 			func = entryPoint;
125 			funcData = userData;
126 			fiber = ::CreateFiber( stackSize, FiberFuncInternal, this );
127 			MT_ASSERT(fiber != nullptr, "Can't create fiber");
128 		}
129 
130 #ifdef MT_INSTRUMENTED_BUILD
SetName(const char * fiberName)131 		void SetName(const char* fiberName)
132 		{
133 			MT_UNUSED(fiberName);
134 		}
135 #endif
136 
SwitchTo(Fiber & from,Fiber & to)137 		static void SwitchTo(Fiber & from, Fiber & to)
138 		{
139 			MT_USED_IN_ASSERT(from);
140 
141 			HardwareFullMemoryBarrier();
142 
143 			MT_ASSERT(from.fiber != nullptr, "Invalid from fiber");
144 			MT_ASSERT(to.fiber != nullptr, "Invalid to fiber");
145 
146 			::SwitchToFiber( (void*)to.fiber );
147 		}
148 
149 
150 	};
151 
152 }
153 
154 #endif
155