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 #include <ucontext.h>
26 #include <stdlib.h>
27 #include <string.h>
28 
29 #define _DARWIN_C_SOURCE
30 #include <sys/mman.h>
31 
32 #ifndef MAP_ANONYMOUS
33     #define MAP_ANONYMOUS MAP_ANON
34 #endif
35 
36 #ifndef MAP_STACK
37     #define MAP_STACK (0)
38 #endif
39 
40 #include <MTAllocator.h>
41 
42 namespace MT
43 {
44 
45 	//
46 	//
47 	//
48 	class Fiber
49 	{
50 		void * funcData;
51 		TThreadEntryPoint func;
52 
53 		Memory::StackDesc stackDesc;
54 
55 		ucontext_t fiberContext;
56 		bool isInitialized;
57 
58 		static void FiberFuncInternal(void *pFiber)
59 		{
60 			MT_ASSERT(pFiber != nullptr, "Invalid fiber");
61 			Fiber* self = (Fiber*)pFiber;
62 
63 			MT_ASSERT(self->isInitialized == true, "Using non initialized fiber");
64 
65 			MT_ASSERT(self->func != nullptr, "Invalid fiber func");
66 			self->func(self->funcData);
67 		}
68 
69 	private:
70 
71 		Fiber(const Fiber &) {}
72 		void operator=(const Fiber &) {}
73 
74 	public:
75 
76 		Fiber()
77 			: funcData(nullptr)
78 			, func(nullptr)
79 			, isInitialized(false)
80 		{
81 			memset(&fiberContext, 0, sizeof(ucontext_t));
82 		}
83 
84 		~Fiber()
85 		{
86 			if (isInitialized)
87 			{
88 				// if func != null than we have stack memory ownership
89 				if (func != nullptr)
90 				{
91 					Memory::FreeStack(stackDesc);
92 				}
93 
94 				isInitialized = false;
95 			}
96 		}
97 
98 
99 		void CreateFromThread(Thread & thread)
100 		{
101 			MT_ASSERT(!isInitialized, "Already initialized");
102 			MT_ASSERT(thread.IsCurrentThread(), "ERROR: Can create fiber only from current thread!");
103 
104 			int res = getcontext(&fiberContext);
105 			MT_ASSERT(res == 0, "getcontext - failed");
106 
107 			fiberContext.uc_link = nullptr;
108 			fiberContext.uc_stack.ss_sp = thread.GetStackBottom();
109 			fiberContext.uc_stack.ss_size = thread.GetStackSize();
110 			fiberContext.uc_stack.ss_flags = 0;
111 
112 			func = nullptr;
113 			funcData = nullptr;
114 
115 			isInitialized = true;
116 		}
117 
118 
119 		void Create(size_t stackSize, TThreadEntryPoint entryPoint, void *userData)
120 		{
121 			MT_ASSERT(!isInitialized, "Already initialized");
122 			MT_ASSERT(stackSize >= PTHREAD_STACK_MIN, "Stack to small");
123 
124 			func = entryPoint;
125 			funcData = userData;
126 
127 			int res = getcontext(&fiberContext);
128 			MT_ASSERT(res == 0, "getcontext - failed");
129 
130 			stackDesc = Memory::AllocStack(stackSize);
131 
132 			fiberContext.uc_link = nullptr;
133 			fiberContext.uc_stack.ss_sp = stackDesc.stackBottom;
134 			fiberContext.uc_stack.ss_size = stackDesc.GetStackSize();
135 			fiberContext.uc_stack.ss_flags = 0;
136 
137 			makecontext(&fiberContext, (void(*)())&FiberFuncInternal, 1, (void *)this);
138 
139 			isInitialized = true;
140 		}
141 
142 		static void SwitchTo(Fiber & from, Fiber & to)
143 		{
144 			 __sync_synchronize();
145 
146 			MT_ASSERT(from.isInitialized, "Invalid from fiber");
147 			MT_ASSERT(to.isInitialized, "Invalid to fiber");
148 
149 			int res = swapcontext(&from.fiberContext, &to.fiberContext);
150 			MT_ASSERT(res == 0, "setcontext - failed");
151 
152 		}
153 
154 
155 
156 	};
157 
158 
159 }
160 
161 
162