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2 | // Copyright Oliver Kowalke 2017. | |
3 | // Distributed under the Boost Software License, Version 1.0. | |
4 | // (See accompanying file LICENSE_1_0.txt or copy at | |
5 | // http://www.boost.org/LICENSE_1_0.txt) | |
6 | ||
7 | #ifndef BOOST_CONTEXT_FIBER_H | |
8 | #define BOOST_CONTEXT_FIBER_H | |
9 | ||
10 | #include <windows.h> | |
11 | ||
12 | #include <boost/context/detail/config.hpp> | |
13 | ||
14 | #include <algorithm> | |
15 | #include <cstddef> | |
16 | #include <cstdint> | |
17 | #include <cstdlib> | |
18 | #include <cstring> | |
19 | #include <functional> | |
20 | #include <memory> | |
21 | #include <ostream> | |
22 | #include <system_error> | |
23 | #include <tuple> | |
24 | #include <utility> | |
25 | ||
26 | #include <boost/assert.hpp> | |
27 | #include <boost/config.hpp> | |
28 | ||
29 | #include <boost/context/detail/disable_overload.hpp> | |
30 | #if defined(BOOST_NO_CXX14_STD_EXCHANGE) | |
31 | #include <boost/context/detail/exchange.hpp> | |
32 | #endif | |
33 | #if defined(BOOST_NO_CXX17_STD_INVOKE) | |
34 | #include <boost/context/detail/invoke.hpp> | |
35 | #endif | |
36 | #include <boost/context/fixedsize_stack.hpp> | |
37 | #include <boost/context/flags.hpp> | |
38 | #include <boost/context/preallocated.hpp> | |
39 | #include <boost/context/stack_context.hpp> | |
40 | ||
41 | #ifdef BOOST_HAS_ABI_HEADERS | |
42 | # include BOOST_ABI_PREFIX | |
43 | #endif | |
44 | ||
45 | #if defined(BOOST_MSVC) | |
46 | # pragma warning(push) | |
47 | # pragma warning(disable: 4702) | |
48 | #endif | |
49 | ||
50 | namespace boost { | |
51 | namespace context { | |
52 | namespace detail { | |
53 | ||
54 | // tampoline function | |
55 | // entered if the execution context | |
56 | // is resumed for the first time | |
57 | template< typename Record > | |
58 | static VOID WINAPI fiber_entry_func( LPVOID data) noexcept { | |
59 | Record * record = static_cast< Record * >( data); | |
60 | BOOST_ASSERT( nullptr != record); | |
61 | // start execution of toplevel context-function | |
62 | record->run(); | |
63 | } | |
64 | ||
65 | struct BOOST_CONTEXT_DECL fiber_activation_record { | |
66 | LPVOID fiber{ nullptr }; | |
67 | stack_context sctx{}; | |
68 | bool main_ctx{ true }; | |
69 | fiber_activation_record * from{ nullptr }; | |
70 | std::function< fiber_activation_record*(fiber_activation_record*&) > ontop{}; | |
71 | bool terminated{ false }; | |
72 | bool force_unwind{ false }; | |
73 | ||
74 | static fiber_activation_record *& current() noexcept; | |
75 | ||
76 | // used for toplevel-context | |
77 | // (e.g. main context, thread-entry context) | |
78 | fiber_activation_record() noexcept { | |
79 | #if ( _WIN32_WINNT > 0x0600) | |
80 | if ( ::IsThreadAFiber() ) { | |
81 | fiber = ::GetCurrentFiber(); | |
82 | } else { | |
83 | fiber = ::ConvertThreadToFiber( nullptr); | |
84 | } | |
85 | #else | |
86 | fiber = ::ConvertThreadToFiber( nullptr); | |
87 | if ( BOOST_UNLIKELY( nullptr == fiber) ) { | |
92f5a8d4 | 88 | BOOST_ASSERT( ERROR_ALREADY_FIBER == ::GetLastError()); |
11fdf7f2 TL |
89 | fiber = ::GetCurrentFiber(); |
90 | BOOST_ASSERT( nullptr != fiber); | |
91 | BOOST_ASSERT( reinterpret_cast< LPVOID >( 0x1E00) != fiber); | |
92 | } | |
93 | #endif | |
94 | } | |
95 | ||
96 | fiber_activation_record( stack_context sctx_) noexcept : | |
97 | sctx{ sctx_ }, | |
98 | main_ctx{ false } { | |
99 | } | |
100 | ||
101 | virtual ~fiber_activation_record() { | |
102 | if ( BOOST_UNLIKELY( main_ctx) ) { | |
103 | ::ConvertFiberToThread(); | |
104 | } else { | |
105 | ::DeleteFiber( fiber); | |
106 | } | |
107 | } | |
108 | ||
109 | fiber_activation_record( fiber_activation_record const&) = delete; | |
110 | fiber_activation_record & operator=( fiber_activation_record const&) = delete; | |
111 | ||
112 | bool is_main_context() const noexcept { | |
113 | return main_ctx; | |
114 | } | |
115 | ||
116 | fiber_activation_record * resume() { | |
117 | from = current(); | |
118 | // store `this` in static, thread local pointer | |
119 | // `this` will become the active (running) context | |
120 | current() = this; | |
121 | // context switch from parent context to `this`-context | |
122 | // context switch | |
123 | ::SwitchToFiber( fiber); | |
124 | #if defined(BOOST_NO_CXX14_STD_EXCHANGE) | |
125 | return detail::exchange( current()->from, nullptr); | |
126 | #else | |
127 | return std::exchange( current()->from, nullptr); | |
128 | #endif | |
129 | } | |
130 | ||
131 | template< typename Ctx, typename Fn > | |
132 | fiber_activation_record * resume_with( Fn && fn) { | |
133 | from = current(); | |
134 | // store `this` in static, thread local pointer | |
135 | // `this` will become the active (running) context | |
136 | // returned by fiber::current() | |
137 | current() = this; | |
138 | #if defined(BOOST_NO_CXX14_GENERIC_LAMBDAS) | |
139 | current()->ontop = std::bind( | |
140 | [](typename std::decay< Fn >::type & fn, fiber_activation_record *& ptr){ | |
141 | Ctx c{ ptr }; | |
142 | c = fn( std::move( c) ); | |
143 | if ( ! c) { | |
144 | ptr = nullptr; | |
145 | } | |
146 | #if defined(BOOST_NO_CXX14_STD_EXCHANGE) | |
147 | return exchange( c.ptr_, nullptr); | |
148 | #else | |
149 | return std::exchange( c.ptr_, nullptr); | |
150 | #endif | |
151 | }, | |
152 | std::forward< Fn >( fn), | |
153 | std::placeholders::_1); | |
154 | #else | |
155 | current()->ontop = [fn=std::forward<Fn>(fn)](fiber_activation_record *& ptr){ | |
156 | Ctx c{ ptr }; | |
157 | c = fn( std::move( c) ); | |
158 | if ( ! c) { | |
159 | ptr = nullptr; | |
160 | } | |
161 | #if defined(BOOST_NO_CXX14_STD_EXCHANGE) | |
162 | return exchange( c.ptr_, nullptr); | |
163 | #else | |
164 | return std::exchange( c.ptr_, nullptr); | |
165 | #endif | |
166 | }; | |
167 | #endif | |
168 | // context switch | |
169 | ::SwitchToFiber( fiber); | |
170 | #if defined(BOOST_NO_CXX14_STD_EXCHANGE) | |
171 | return detail::exchange( current()->from, nullptr); | |
172 | #else | |
173 | return std::exchange( current()->from, nullptr); | |
174 | #endif | |
175 | } | |
176 | ||
177 | virtual void deallocate() noexcept { | |
178 | } | |
179 | }; | |
180 | ||
181 | struct BOOST_CONTEXT_DECL fiber_activation_record_initializer { | |
182 | fiber_activation_record_initializer() noexcept; | |
183 | ~fiber_activation_record_initializer(); | |
184 | }; | |
185 | ||
186 | struct forced_unwind { | |
92f5a8d4 TL |
187 | fiber_activation_record * from{ nullptr }; |
188 | #ifndef BOOST_ASSERT_IS_VOID | |
189 | bool caught{ false }; | |
190 | #endif | |
11fdf7f2 TL |
191 | |
192 | explicit forced_unwind( fiber_activation_record * from_) : | |
193 | from{ from_ } { | |
194 | } | |
92f5a8d4 TL |
195 | |
196 | #ifndef BOOST_ASSERT_IS_VOID | |
197 | ~forced_unwind() { | |
198 | BOOST_ASSERT( caught); | |
199 | } | |
200 | #endif | |
11fdf7f2 TL |
201 | }; |
202 | ||
203 | template< typename Ctx, typename StackAlloc, typename Fn > | |
204 | class fiber_capture_record : public fiber_activation_record { | |
205 | private: | |
206 | typename std::decay< StackAlloc >::type salloc_; | |
207 | typename std::decay< Fn >::type fn_; | |
208 | ||
209 | static void destroy( fiber_capture_record * p) noexcept { | |
210 | typename std::decay< StackAlloc >::type salloc = std::move( p->salloc_); | |
211 | stack_context sctx = p->sctx; | |
212 | // deallocate activation record | |
213 | p->~fiber_capture_record(); | |
214 | // destroy stack with stack allocator | |
215 | salloc.deallocate( sctx); | |
216 | } | |
217 | ||
218 | public: | |
219 | fiber_capture_record( stack_context sctx, StackAlloc && salloc, Fn && fn) noexcept : | |
220 | fiber_activation_record( sctx), | |
221 | salloc_( std::forward< StackAlloc >( salloc)), | |
222 | fn_( std::forward< Fn >( fn) ) { | |
223 | } | |
224 | ||
225 | void deallocate() noexcept override final { | |
226 | BOOST_ASSERT( main_ctx || ( ! main_ctx && terminated) ); | |
227 | destroy( this); | |
228 | } | |
229 | ||
230 | void run() { | |
231 | Ctx c{ from }; | |
232 | try { | |
233 | // invoke context-function | |
234 | #if defined(BOOST_NO_CXX17_STD_INVOKE) | |
235 | c = boost::context::detail::invoke( fn_, std::move( c) ); | |
236 | #else | |
237 | c = std::invoke( fn_, std::move( c) ); | |
238 | #endif | |
239 | } catch ( forced_unwind const& ex) { | |
240 | c = Ctx{ ex.from }; | |
92f5a8d4 TL |
241 | #ifndef BOOST_ASSERT_IS_VOID |
242 | const_cast< forced_unwind & >( ex).caught = true; | |
243 | #endif | |
11fdf7f2 TL |
244 | } |
245 | // this context has finished its task | |
246 | from = nullptr; | |
247 | ontop = nullptr; | |
248 | terminated = true; | |
249 | force_unwind = false; | |
250 | std::move( c).resume(); | |
251 | BOOST_ASSERT_MSG( false, "fiber already terminated"); | |
252 | } | |
253 | }; | |
254 | ||
255 | template< typename Ctx, typename StackAlloc, typename Fn > | |
256 | static fiber_activation_record * create_fiber1( StackAlloc && salloc, Fn && fn) { | |
257 | typedef fiber_capture_record< Ctx, StackAlloc, Fn > capture_t; | |
258 | ||
259 | auto sctx = salloc.allocate(); | |
260 | BOOST_ASSERT( ( sizeof( capture_t) ) < sctx.size); | |
261 | // reserve space for control structure | |
262 | void * storage = reinterpret_cast< void * >( | |
263 | ( reinterpret_cast< uintptr_t >( sctx.sp) - static_cast< uintptr_t >( sizeof( capture_t) ) ) | |
264 | & ~ static_cast< uintptr_t >( 0xff) ); | |
265 | // placment new for control structure on context stack | |
266 | capture_t * record = new ( storage) capture_t{ | |
267 | sctx, std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) }; | |
268 | // create user-context | |
269 | record->fiber = ::CreateFiber( sctx.size, & detail::fiber_entry_func< capture_t >, record); | |
270 | return record; | |
271 | } | |
272 | ||
273 | template< typename Ctx, typename StackAlloc, typename Fn > | |
274 | static fiber_activation_record * create_fiber2( preallocated palloc, StackAlloc && salloc, Fn && fn) { | |
275 | typedef fiber_capture_record< Ctx, StackAlloc, Fn > capture_t; | |
276 | ||
277 | BOOST_ASSERT( ( sizeof( capture_t) ) < palloc.size); | |
278 | // reserve space for control structure | |
279 | void * storage = reinterpret_cast< void * >( | |
280 | ( reinterpret_cast< uintptr_t >( palloc.sp) - static_cast< uintptr_t >( sizeof( capture_t) ) ) | |
281 | & ~ static_cast< uintptr_t >( 0xff) ); | |
282 | // placment new for control structure on context stack | |
283 | capture_t * record = new ( storage) capture_t{ | |
284 | palloc.sctx, std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) }; | |
285 | // create user-context | |
286 | record->fiber = ::CreateFiber( palloc.sctx.size, & detail::fiber_entry_func< capture_t >, record); | |
287 | return record; | |
288 | } | |
289 | ||
290 | } | |
291 | ||
292 | class BOOST_CONTEXT_DECL fiber { | |
293 | private: | |
294 | friend struct detail::fiber_activation_record; | |
295 | ||
296 | template< typename Ctx, typename StackAlloc, typename Fn > | |
297 | friend class detail::fiber_capture_record; | |
298 | ||
299 | template< typename Ctx, typename StackAlloc, typename Fn > | |
300 | friend detail::fiber_activation_record * detail::create_fiber1( StackAlloc &&, Fn &&); | |
301 | ||
302 | template< typename Ctx, typename StackAlloc, typename Fn > | |
303 | friend detail::fiber_activation_record * detail::create_fiber2( preallocated, StackAlloc &&, Fn &&); | |
304 | ||
305 | template< typename StackAlloc, typename Fn > | |
306 | friend fiber | |
307 | callcc( std::allocator_arg_t, StackAlloc &&, Fn &&); | |
308 | ||
309 | template< typename StackAlloc, typename Fn > | |
310 | friend fiber | |
311 | callcc( std::allocator_arg_t, preallocated, StackAlloc &&, Fn &&); | |
312 | ||
313 | detail::fiber_activation_record * ptr_{ nullptr }; | |
314 | ||
315 | fiber( detail::fiber_activation_record * ptr) noexcept : | |
316 | ptr_{ ptr } { | |
317 | } | |
318 | ||
319 | public: | |
320 | fiber() = default; | |
321 | ||
322 | template< typename Fn, typename = detail::disable_overload< fiber, Fn > > | |
323 | fiber( Fn && fn) : | |
324 | fiber{ std::allocator_arg, | |
325 | fixedsize_stack(), | |
326 | std::forward< Fn >( fn) } { | |
327 | } | |
328 | ||
329 | template< typename StackAlloc, typename Fn > | |
330 | fiber( std::allocator_arg_t, StackAlloc && salloc, Fn && fn) : | |
331 | ptr_{ detail::create_fiber1< fiber >( | |
332 | std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) ) } {; | |
333 | } | |
334 | ||
335 | template< typename StackAlloc, typename Fn > | |
336 | fiber( std::allocator_arg_t, preallocated palloc, StackAlloc && salloc, Fn && fn) : | |
337 | ptr_{ detail::create_fiber2< fiber >( | |
338 | palloc, std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) ) } { | |
339 | } | |
340 | ||
341 | ~fiber() { | |
342 | if ( BOOST_UNLIKELY( nullptr != ptr_) && ! ptr_->main_ctx) { | |
343 | if ( BOOST_LIKELY( ! ptr_->terminated) ) { | |
344 | ptr_->force_unwind = true; | |
345 | ptr_->resume(); | |
346 | BOOST_ASSERT( ptr_->terminated); | |
347 | } | |
348 | ptr_->deallocate(); | |
349 | } | |
350 | } | |
351 | ||
352 | fiber( fiber const&) = delete; | |
353 | fiber & operator=( fiber const&) = delete; | |
354 | ||
355 | fiber( fiber && other) noexcept { | |
356 | swap( other); | |
357 | } | |
358 | ||
359 | fiber & operator=( fiber && other) noexcept { | |
360 | if ( BOOST_LIKELY( this != & other) ) { | |
361 | fiber tmp = std::move( other); | |
362 | swap( tmp); | |
363 | } | |
364 | return * this; | |
365 | } | |
366 | ||
367 | fiber resume() && { | |
368 | BOOST_ASSERT( nullptr != ptr_); | |
369 | #if defined(BOOST_NO_CXX14_STD_EXCHANGE) | |
370 | detail::fiber_activation_record * ptr = detail::exchange( ptr_, nullptr)->resume(); | |
371 | #else | |
372 | detail::fiber_activation_record * ptr = std::exchange( ptr_, nullptr)->resume(); | |
373 | #endif | |
374 | if ( BOOST_UNLIKELY( detail::fiber_activation_record::current()->force_unwind) ) { | |
375 | throw detail::forced_unwind{ ptr}; | |
376 | } else if ( BOOST_UNLIKELY( nullptr != detail::fiber_activation_record::current()->ontop) ) { | |
377 | ptr = detail::fiber_activation_record::current()->ontop( ptr); | |
378 | detail::fiber_activation_record::current()->ontop = nullptr; | |
379 | } | |
380 | return { ptr }; | |
381 | } | |
382 | ||
383 | template< typename Fn > | |
384 | fiber resume_with( Fn && fn) && { | |
385 | BOOST_ASSERT( nullptr != ptr_); | |
386 | #if defined(BOOST_NO_CXX14_STD_EXCHANGE) | |
387 | detail::fiber_activation_record * ptr = | |
388 | detail::exchange( ptr_, nullptr)->resume_with< fiber >( std::forward< Fn >( fn) ); | |
389 | #else | |
390 | detail::fiber_activation_record * ptr = | |
391 | std::exchange( ptr_, nullptr)->resume_with< fiber >( std::forward< Fn >( fn) ); | |
392 | #endif | |
393 | if ( BOOST_UNLIKELY( detail::fiber_activation_record::current()->force_unwind) ) { | |
394 | throw detail::forced_unwind{ ptr}; | |
395 | } else if ( BOOST_UNLIKELY( nullptr != detail::fiber_activation_record::current()->ontop) ) { | |
396 | ptr = detail::fiber_activation_record::current()->ontop( ptr); | |
397 | detail::fiber_activation_record::current()->ontop = nullptr; | |
398 | } | |
399 | return { ptr }; | |
400 | } | |
401 | ||
402 | explicit operator bool() const noexcept { | |
403 | return nullptr != ptr_ && ! ptr_->terminated; | |
404 | } | |
405 | ||
406 | bool operator!() const noexcept { | |
407 | return nullptr == ptr_ || ptr_->terminated; | |
408 | } | |
409 | ||
11fdf7f2 TL |
410 | bool operator<( fiber const& other) const noexcept { |
411 | return ptr_ < other.ptr_; | |
412 | } | |
20effc67 TL |
413 | |
414 | #if !defined(BOOST_EMBTC) | |
415 | ||
11fdf7f2 TL |
416 | template< typename charT, class traitsT > |
417 | friend std::basic_ostream< charT, traitsT > & | |
418 | operator<<( std::basic_ostream< charT, traitsT > & os, fiber const& other) { | |
419 | if ( nullptr != other.ptr_) { | |
420 | return os << other.ptr_; | |
421 | } else { | |
422 | return os << "{not-a-context}"; | |
423 | } | |
424 | } | |
425 | ||
20effc67 TL |
426 | #else |
427 | ||
428 | template< typename charT, class traitsT > | |
429 | friend std::basic_ostream< charT, traitsT > & | |
430 | operator<<( std::basic_ostream< charT, traitsT > & os, fiber const& other); | |
431 | ||
432 | #endif | |
433 | ||
11fdf7f2 TL |
434 | void swap( fiber & other) noexcept { |
435 | std::swap( ptr_, other.ptr_); | |
436 | } | |
437 | }; | |
438 | ||
20effc67 TL |
439 | #if defined(BOOST_EMBTC) |
440 | ||
441 | template< typename charT, class traitsT > | |
442 | inline std::basic_ostream< charT, traitsT > & | |
443 | operator<<( std::basic_ostream< charT, traitsT > & os, fiber const& other) { | |
444 | if ( nullptr != other.ptr_) { | |
445 | return os << other.ptr_; | |
446 | } else { | |
447 | return os << "{not-a-context}"; | |
448 | } | |
449 | } | |
450 | ||
451 | #endif | |
452 | ||
11fdf7f2 TL |
453 | inline |
454 | void swap( fiber & l, fiber & r) noexcept { | |
455 | l.swap( r); | |
456 | } | |
457 | ||
92f5a8d4 TL |
458 | typedef fiber fiber_context; |
459 | ||
11fdf7f2 TL |
460 | }} |
461 | ||
462 | #if defined(BOOST_MSVC) | |
463 | # pragma warning(pop) | |
464 | #endif | |
465 | ||
466 | #ifdef BOOST_HAS_ABI_HEADERS | |
467 | # include BOOST_ABI_SUFFIX | |
468 | #endif | |
469 | ||
470 | #endif // BOOST_CONTEXT_FIBER_H |