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7c673cae FG |
1 | // lock-free queue from |
2 | // Michael, M. M. and Scott, M. L., | |
3 | // "simple, fast and practical non-blocking and blocking concurrent queue algorithms" | |
4 | // | |
5 | // Copyright (C) 2008-2013 Tim Blechmann | |
6 | // | |
7 | // Distributed under the Boost Software License, Version 1.0. (See | |
8 | // accompanying file LICENSE_1_0.txt or copy at | |
9 | // http://www.boost.org/LICENSE_1_0.txt) | |
10 | ||
11 | #ifndef BOOST_LOCKFREE_FIFO_HPP_INCLUDED | |
12 | #define BOOST_LOCKFREE_FIFO_HPP_INCLUDED | |
13 | ||
14 | #include <boost/assert.hpp> | |
15 | #include <boost/static_assert.hpp> | |
20effc67 | 16 | #include <boost/core/allocator_access.hpp> |
7c673cae FG |
17 | #include <boost/type_traits/has_trivial_assign.hpp> |
18 | #include <boost/type_traits/has_trivial_destructor.hpp> | |
19 | #include <boost/config.hpp> // for BOOST_LIKELY & BOOST_ALIGNMENT | |
20 | ||
21 | #include <boost/lockfree/detail/atomic.hpp> | |
22 | #include <boost/lockfree/detail/copy_payload.hpp> | |
23 | #include <boost/lockfree/detail/freelist.hpp> | |
24 | #include <boost/lockfree/detail/parameter.hpp> | |
25 | #include <boost/lockfree/detail/tagged_ptr.hpp> | |
26 | ||
27 | #include <boost/lockfree/lockfree_forward.hpp> | |
28 | ||
29 | #ifdef BOOST_HAS_PRAGMA_ONCE | |
30 | #pragma once | |
31 | #endif | |
32 | ||
33 | ||
34 | #if defined(_MSC_VER) | |
35 | #pragma warning(push) | |
36 | #pragma warning(disable: 4324) // structure was padded due to __declspec(align()) | |
37 | #endif | |
38 | ||
92f5a8d4 TL |
39 | #if defined(BOOST_INTEL) && (BOOST_INTEL_CXX_VERSION > 1000) |
40 | #pragma warning(push) | |
41 | #pragma warning(disable:488) // template parameter unused in declaring parameter types, | |
42 | // gets erronously triggered the queue constructor which | |
43 | // takes an allocator of another type and rebinds it | |
44 | #endif | |
45 | ||
46 | ||
7c673cae FG |
47 | |
48 | namespace boost { | |
49 | namespace lockfree { | |
50 | namespace detail { | |
51 | ||
52 | typedef parameter::parameters<boost::parameter::optional<tag::allocator>, | |
53 | boost::parameter::optional<tag::capacity> | |
54 | > queue_signature; | |
55 | ||
56 | } /* namespace detail */ | |
57 | ||
58 | ||
59 | /** The queue class provides a multi-writer/multi-reader queue, pushing and popping is lock-free, | |
60 | * construction/destruction has to be synchronized. It uses a freelist for memory management, | |
61 | * freed nodes are pushed to the freelist and not returned to the OS before the queue is destroyed. | |
62 | * | |
63 | * \b Policies: | |
64 | * - \ref boost::lockfree::fixed_sized, defaults to \c boost::lockfree::fixed_sized<false> \n | |
65 | * Can be used to completely disable dynamic memory allocations during push in order to ensure lockfree behavior. \n | |
66 | * If the data structure is configured as fixed-sized, the internal nodes are stored inside an array and they are addressed | |
67 | * by array indexing. This limits the possible size of the queue to the number of elements that can be addressed by the index | |
68 | * type (usually 2**16-2), but on platforms that lack double-width compare-and-exchange instructions, this is the best way | |
69 | * to achieve lock-freedom. | |
70 | * | |
71 | * - \ref boost::lockfree::capacity, optional \n | |
72 | * If this template argument is passed to the options, the size of the queue is set at compile-time.\n | |
b32b8144 | 73 | * This option implies \c fixed_sized<true> |
7c673cae FG |
74 | * |
75 | * - \ref boost::lockfree::allocator, defaults to \c boost::lockfree::allocator<std::allocator<void>> \n | |
76 | * Specifies the allocator that is used for the internal freelist | |
77 | * | |
78 | * \b Requirements: | |
79 | * - T must have a copy constructor | |
80 | * - T must have a trivial assignment operator | |
81 | * - T must have a trivial destructor | |
82 | * | |
83 | * */ | |
84 | #ifdef BOOST_NO_CXX11_VARIADIC_TEMPLATES | |
85 | template <typename T, class A0, class A1, class A2> | |
86 | #else | |
87 | template <typename T, typename ...Options> | |
88 | #endif | |
89 | class queue | |
90 | { | |
91 | private: | |
92 | #ifndef BOOST_DOXYGEN_INVOKED | |
93 | ||
94 | #ifdef BOOST_HAS_TRIVIAL_DESTRUCTOR | |
95 | BOOST_STATIC_ASSERT((boost::has_trivial_destructor<T>::value)); | |
96 | #endif | |
97 | ||
98 | #ifdef BOOST_HAS_TRIVIAL_ASSIGN | |
99 | BOOST_STATIC_ASSERT((boost::has_trivial_assign<T>::value)); | |
100 | #endif | |
101 | ||
102 | #ifdef BOOST_NO_CXX11_VARIADIC_TEMPLATES | |
103 | typedef typename detail::queue_signature::bind<A0, A1, A2>::type bound_args; | |
104 | #else | |
105 | typedef typename detail::queue_signature::bind<Options...>::type bound_args; | |
106 | #endif | |
107 | ||
108 | static const bool has_capacity = detail::extract_capacity<bound_args>::has_capacity; | |
109 | static const size_t capacity = detail::extract_capacity<bound_args>::capacity + 1; // the queue uses one dummy node | |
110 | static const bool fixed_sized = detail::extract_fixed_sized<bound_args>::value; | |
111 | static const bool node_based = !(has_capacity || fixed_sized); | |
112 | static const bool compile_time_sized = has_capacity; | |
113 | ||
114 | struct BOOST_ALIGNMENT(BOOST_LOCKFREE_CACHELINE_BYTES) node | |
115 | { | |
116 | typedef typename detail::select_tagged_handle<node, node_based>::tagged_handle_type tagged_node_handle; | |
117 | typedef typename detail::select_tagged_handle<node, node_based>::handle_type handle_type; | |
118 | ||
119 | node(T const & v, handle_type null_handle): | |
20effc67 | 120 | data(v) |
7c673cae FG |
121 | { |
122 | /* increment tag to avoid ABA problem */ | |
123 | tagged_node_handle old_next = next.load(memory_order_relaxed); | |
124 | tagged_node_handle new_next (null_handle, old_next.get_next_tag()); | |
125 | next.store(new_next, memory_order_release); | |
126 | } | |
127 | ||
128 | node (handle_type null_handle): | |
129 | next(tagged_node_handle(null_handle, 0)) | |
130 | {} | |
131 | ||
132 | node(void) | |
133 | {} | |
134 | ||
135 | atomic<tagged_node_handle> next; | |
136 | T data; | |
137 | }; | |
138 | ||
139 | typedef typename detail::extract_allocator<bound_args, node>::type node_allocator; | |
140 | typedef typename detail::select_freelist<node, node_allocator, compile_time_sized, fixed_sized, capacity>::type pool_t; | |
141 | typedef typename pool_t::tagged_node_handle tagged_node_handle; | |
142 | typedef typename detail::select_tagged_handle<node, node_based>::handle_type handle_type; | |
143 | ||
144 | void initialize(void) | |
145 | { | |
146 | node * n = pool.template construct<true, false>(pool.null_handle()); | |
147 | tagged_node_handle dummy_node(pool.get_handle(n), 0); | |
148 | head_.store(dummy_node, memory_order_relaxed); | |
149 | tail_.store(dummy_node, memory_order_release); | |
150 | } | |
151 | ||
152 | struct implementation_defined | |
153 | { | |
154 | typedef node_allocator allocator; | |
155 | typedef std::size_t size_type; | |
156 | }; | |
157 | ||
158 | #endif | |
159 | ||
160 | BOOST_DELETED_FUNCTION(queue(queue const&)) | |
161 | BOOST_DELETED_FUNCTION(queue& operator= (queue const&)) | |
162 | ||
163 | public: | |
164 | typedef T value_type; | |
165 | typedef typename implementation_defined::allocator allocator; | |
166 | typedef typename implementation_defined::size_type size_type; | |
167 | ||
168 | /** | |
169 | * \return true, if implementation is lock-free. | |
170 | * | |
171 | * \warning It only checks, if the queue head and tail nodes and the freelist can be modified in a lock-free manner. | |
172 | * On most platforms, the whole implementation is lock-free, if this is true. Using c++0x-style atomics, there is | |
173 | * no possibility to provide a completely accurate implementation, because one would need to test every internal | |
174 | * node, which is impossible if further nodes will be allocated from the operating system. | |
175 | * */ | |
176 | bool is_lock_free (void) const | |
177 | { | |
178 | return head_.is_lock_free() && tail_.is_lock_free() && pool.is_lock_free(); | |
179 | } | |
180 | ||
20effc67 TL |
181 | /** Construct a fixed-sized queue |
182 | * | |
183 | * \pre Must specify a capacity<> argument | |
184 | * */ | |
7c673cae FG |
185 | queue(void): |
186 | head_(tagged_node_handle(0, 0)), | |
187 | tail_(tagged_node_handle(0, 0)), | |
188 | pool(node_allocator(), capacity) | |
189 | { | |
20effc67 TL |
190 | // Don't use BOOST_STATIC_ASSERT() here since it will be evaluated when compiling |
191 | // this function and this function may be compiled even when it isn't being used. | |
7c673cae FG |
192 | BOOST_ASSERT(has_capacity); |
193 | initialize(); | |
194 | } | |
195 | ||
20effc67 TL |
196 | /** Construct a fixed-sized queue with a custom allocator |
197 | * | |
198 | * \pre Must specify a capacity<> argument | |
199 | * */ | |
7c673cae | 200 | template <typename U> |
20effc67 | 201 | explicit queue(typename boost::allocator_rebind<node_allocator, U>::type const & alloc): |
7c673cae FG |
202 | head_(tagged_node_handle(0, 0)), |
203 | tail_(tagged_node_handle(0, 0)), | |
204 | pool(alloc, capacity) | |
205 | { | |
206 | BOOST_STATIC_ASSERT(has_capacity); | |
207 | initialize(); | |
208 | } | |
209 | ||
20effc67 TL |
210 | /** Construct a fixed-sized queue with a custom allocator |
211 | * | |
212 | * \pre Must specify a capacity<> argument | |
213 | * */ | |
7c673cae FG |
214 | explicit queue(allocator const & alloc): |
215 | head_(tagged_node_handle(0, 0)), | |
216 | tail_(tagged_node_handle(0, 0)), | |
217 | pool(alloc, capacity) | |
218 | { | |
20effc67 TL |
219 | // Don't use BOOST_STATIC_ASSERT() here since it will be evaluated when compiling |
220 | // this function and this function may be compiled even when it isn't being used. | |
7c673cae FG |
221 | BOOST_ASSERT(has_capacity); |
222 | initialize(); | |
223 | } | |
7c673cae | 224 | |
20effc67 TL |
225 | /** Construct a variable-sized queue |
226 | * | |
227 | * Allocate n nodes initially for the freelist | |
228 | * | |
229 | * \pre Must \b not specify a capacity<> argument | |
230 | * */ | |
7c673cae FG |
231 | explicit queue(size_type n): |
232 | head_(tagged_node_handle(0, 0)), | |
233 | tail_(tagged_node_handle(0, 0)), | |
234 | pool(node_allocator(), n + 1) | |
235 | { | |
20effc67 TL |
236 | // Don't use BOOST_STATIC_ASSERT() here since it will be evaluated when compiling |
237 | // this function and this function may be compiled even when it isn't being used. | |
7c673cae FG |
238 | BOOST_ASSERT(!has_capacity); |
239 | initialize(); | |
240 | } | |
241 | ||
20effc67 TL |
242 | /** Construct a variable-sized queue with a custom allocator |
243 | * | |
244 | * Allocate n nodes initially for the freelist | |
245 | * | |
246 | * \pre Must \b not specify a capacity<> argument | |
247 | * */ | |
7c673cae | 248 | template <typename U> |
20effc67 | 249 | queue(size_type n, typename boost::allocator_rebind<node_allocator, U>::type const & alloc): |
7c673cae FG |
250 | head_(tagged_node_handle(0, 0)), |
251 | tail_(tagged_node_handle(0, 0)), | |
252 | pool(alloc, n + 1) | |
253 | { | |
254 | BOOST_STATIC_ASSERT(!has_capacity); | |
255 | initialize(); | |
256 | } | |
7c673cae FG |
257 | |
258 | /** \copydoc boost::lockfree::stack::reserve | |
259 | * */ | |
260 | void reserve(size_type n) | |
261 | { | |
262 | pool.template reserve<true>(n); | |
263 | } | |
264 | ||
265 | /** \copydoc boost::lockfree::stack::reserve_unsafe | |
266 | * */ | |
267 | void reserve_unsafe(size_type n) | |
268 | { | |
269 | pool.template reserve<false>(n); | |
270 | } | |
271 | ||
272 | /** Destroys queue, free all nodes from freelist. | |
273 | * */ | |
274 | ~queue(void) | |
275 | { | |
276 | T dummy; | |
277 | while(unsynchronized_pop(dummy)) | |
278 | {} | |
279 | ||
280 | pool.template destruct<false>(head_.load(memory_order_relaxed)); | |
281 | } | |
282 | ||
283 | /** Check if the queue is empty | |
284 | * | |
285 | * \return true, if the queue is empty, false otherwise | |
286 | * \note The result is only accurate, if no other thread modifies the queue. Therefore it is rarely practical to use this | |
287 | * value in program logic. | |
288 | * */ | |
289 | bool empty(void) const | |
290 | { | |
291 | return pool.get_handle(head_.load()) == pool.get_handle(tail_.load()); | |
292 | } | |
293 | ||
294 | /** Pushes object t to the queue. | |
295 | * | |
296 | * \post object will be pushed to the queue, if internal node can be allocated | |
297 | * \returns true, if the push operation is successful. | |
298 | * | |
299 | * \note Thread-safe. If internal memory pool is exhausted and the memory pool is not fixed-sized, a new node will be allocated | |
300 | * from the OS. This may not be lock-free. | |
301 | * */ | |
302 | bool push(T const & t) | |
303 | { | |
304 | return do_push<false>(t); | |
305 | } | |
306 | ||
307 | /** Pushes object t to the queue. | |
308 | * | |
309 | * \post object will be pushed to the queue, if internal node can be allocated | |
310 | * \returns true, if the push operation is successful. | |
311 | * | |
312 | * \note Thread-safe and non-blocking. If internal memory pool is exhausted, operation will fail | |
313 | * \throws if memory allocator throws | |
314 | * */ | |
315 | bool bounded_push(T const & t) | |
316 | { | |
317 | return do_push<true>(t); | |
318 | } | |
319 | ||
320 | ||
321 | private: | |
322 | #ifndef BOOST_DOXYGEN_INVOKED | |
323 | template <bool Bounded> | |
324 | bool do_push(T const & t) | |
325 | { | |
326 | node * n = pool.template construct<true, Bounded>(t, pool.null_handle()); | |
327 | handle_type node_handle = pool.get_handle(n); | |
328 | ||
329 | if (n == NULL) | |
330 | return false; | |
331 | ||
332 | for (;;) { | |
333 | tagged_node_handle tail = tail_.load(memory_order_acquire); | |
334 | node * tail_node = pool.get_pointer(tail); | |
335 | tagged_node_handle next = tail_node->next.load(memory_order_acquire); | |
336 | node * next_ptr = pool.get_pointer(next); | |
337 | ||
338 | tagged_node_handle tail2 = tail_.load(memory_order_acquire); | |
339 | if (BOOST_LIKELY(tail == tail2)) { | |
340 | if (next_ptr == 0) { | |
341 | tagged_node_handle new_tail_next(node_handle, next.get_next_tag()); | |
342 | if ( tail_node->next.compare_exchange_weak(next, new_tail_next) ) { | |
343 | tagged_node_handle new_tail(node_handle, tail.get_next_tag()); | |
344 | tail_.compare_exchange_strong(tail, new_tail); | |
345 | return true; | |
346 | } | |
347 | } | |
348 | else { | |
349 | tagged_node_handle new_tail(pool.get_handle(next_ptr), tail.get_next_tag()); | |
350 | tail_.compare_exchange_strong(tail, new_tail); | |
351 | } | |
352 | } | |
353 | } | |
354 | } | |
355 | #endif | |
356 | ||
357 | public: | |
358 | ||
359 | /** Pushes object t to the queue. | |
360 | * | |
361 | * \post object will be pushed to the queue, if internal node can be allocated | |
362 | * \returns true, if the push operation is successful. | |
363 | * | |
364 | * \note Not Thread-safe. If internal memory pool is exhausted and the memory pool is not fixed-sized, a new node will be allocated | |
365 | * from the OS. This may not be lock-free. | |
366 | * \throws if memory allocator throws | |
367 | * */ | |
368 | bool unsynchronized_push(T const & t) | |
369 | { | |
370 | node * n = pool.template construct<false, false>(t, pool.null_handle()); | |
371 | ||
372 | if (n == NULL) | |
373 | return false; | |
374 | ||
375 | for (;;) { | |
376 | tagged_node_handle tail = tail_.load(memory_order_relaxed); | |
377 | tagged_node_handle next = tail->next.load(memory_order_relaxed); | |
378 | node * next_ptr = next.get_ptr(); | |
379 | ||
380 | if (next_ptr == 0) { | |
381 | tail->next.store(tagged_node_handle(n, next.get_next_tag()), memory_order_relaxed); | |
382 | tail_.store(tagged_node_handle(n, tail.get_next_tag()), memory_order_relaxed); | |
383 | return true; | |
384 | } | |
385 | else | |
386 | tail_.store(tagged_node_handle(next_ptr, tail.get_next_tag()), memory_order_relaxed); | |
387 | } | |
388 | } | |
389 | ||
390 | /** Pops object from queue. | |
391 | * | |
392 | * \post if pop operation is successful, object will be copied to ret. | |
393 | * \returns true, if the pop operation is successful, false if queue was empty. | |
394 | * | |
395 | * \note Thread-safe and non-blocking | |
396 | * */ | |
397 | bool pop (T & ret) | |
398 | { | |
399 | return pop<T>(ret); | |
400 | } | |
401 | ||
402 | /** Pops object from queue. | |
403 | * | |
404 | * \pre type U must be constructible by T and copyable, or T must be convertible to U | |
405 | * \post if pop operation is successful, object will be copied to ret. | |
406 | * \returns true, if the pop operation is successful, false if queue was empty. | |
407 | * | |
408 | * \note Thread-safe and non-blocking | |
409 | * */ | |
410 | template <typename U> | |
411 | bool pop (U & ret) | |
412 | { | |
413 | for (;;) { | |
414 | tagged_node_handle head = head_.load(memory_order_acquire); | |
415 | node * head_ptr = pool.get_pointer(head); | |
416 | ||
417 | tagged_node_handle tail = tail_.load(memory_order_acquire); | |
418 | tagged_node_handle next = head_ptr->next.load(memory_order_acquire); | |
419 | node * next_ptr = pool.get_pointer(next); | |
420 | ||
421 | tagged_node_handle head2 = head_.load(memory_order_acquire); | |
422 | if (BOOST_LIKELY(head == head2)) { | |
423 | if (pool.get_handle(head) == pool.get_handle(tail)) { | |
424 | if (next_ptr == 0) | |
425 | return false; | |
426 | ||
427 | tagged_node_handle new_tail(pool.get_handle(next), tail.get_next_tag()); | |
428 | tail_.compare_exchange_strong(tail, new_tail); | |
429 | ||
430 | } else { | |
431 | if (next_ptr == 0) | |
432 | /* this check is not part of the original algorithm as published by michael and scott | |
433 | * | |
434 | * however we reuse the tagged_ptr part for the freelist and clear the next part during node | |
435 | * allocation. we can observe a null-pointer here. | |
436 | * */ | |
437 | continue; | |
438 | detail::copy_payload(next_ptr->data, ret); | |
439 | ||
440 | tagged_node_handle new_head(pool.get_handle(next), head.get_next_tag()); | |
441 | if (head_.compare_exchange_weak(head, new_head)) { | |
442 | pool.template destruct<true>(head); | |
443 | return true; | |
444 | } | |
445 | } | |
446 | } | |
447 | } | |
448 | } | |
449 | ||
450 | /** Pops object from queue. | |
451 | * | |
452 | * \post if pop operation is successful, object will be copied to ret. | |
453 | * \returns true, if the pop operation is successful, false if queue was empty. | |
454 | * | |
455 | * \note Not thread-safe, but non-blocking | |
456 | * | |
457 | * */ | |
458 | bool unsynchronized_pop (T & ret) | |
459 | { | |
460 | return unsynchronized_pop<T>(ret); | |
461 | } | |
462 | ||
463 | /** Pops object from queue. | |
464 | * | |
465 | * \pre type U must be constructible by T and copyable, or T must be convertible to U | |
466 | * \post if pop operation is successful, object will be copied to ret. | |
467 | * \returns true, if the pop operation is successful, false if queue was empty. | |
468 | * | |
469 | * \note Not thread-safe, but non-blocking | |
470 | * | |
471 | * */ | |
472 | template <typename U> | |
473 | bool unsynchronized_pop (U & ret) | |
474 | { | |
475 | for (;;) { | |
476 | tagged_node_handle head = head_.load(memory_order_relaxed); | |
477 | node * head_ptr = pool.get_pointer(head); | |
478 | tagged_node_handle tail = tail_.load(memory_order_relaxed); | |
479 | tagged_node_handle next = head_ptr->next.load(memory_order_relaxed); | |
480 | node * next_ptr = pool.get_pointer(next); | |
481 | ||
482 | if (pool.get_handle(head) == pool.get_handle(tail)) { | |
483 | if (next_ptr == 0) | |
484 | return false; | |
485 | ||
486 | tagged_node_handle new_tail(pool.get_handle(next), tail.get_next_tag()); | |
487 | tail_.store(new_tail); | |
488 | } else { | |
489 | if (next_ptr == 0) | |
490 | /* this check is not part of the original algorithm as published by michael and scott | |
491 | * | |
492 | * however we reuse the tagged_ptr part for the freelist and clear the next part during node | |
493 | * allocation. we can observe a null-pointer here. | |
494 | * */ | |
495 | continue; | |
496 | detail::copy_payload(next_ptr->data, ret); | |
497 | tagged_node_handle new_head(pool.get_handle(next), head.get_next_tag()); | |
498 | head_.store(new_head); | |
499 | pool.template destruct<false>(head); | |
500 | return true; | |
501 | } | |
502 | } | |
503 | } | |
504 | ||
505 | /** consumes one element via a functor | |
506 | * | |
507 | * pops one element from the queue and applies the functor on this object | |
508 | * | |
509 | * \returns true, if one element was consumed | |
510 | * | |
511 | * \note Thread-safe and non-blocking, if functor is thread-safe and non-blocking | |
512 | * */ | |
513 | template <typename Functor> | |
514 | bool consume_one(Functor & f) | |
515 | { | |
516 | T element; | |
517 | bool success = pop(element); | |
518 | if (success) | |
519 | f(element); | |
520 | ||
521 | return success; | |
522 | } | |
523 | ||
524 | /// \copydoc boost::lockfree::queue::consume_one(Functor & rhs) | |
525 | template <typename Functor> | |
526 | bool consume_one(Functor const & f) | |
527 | { | |
528 | T element; | |
529 | bool success = pop(element); | |
530 | if (success) | |
531 | f(element); | |
532 | ||
533 | return success; | |
534 | } | |
535 | ||
536 | /** consumes all elements via a functor | |
537 | * | |
538 | * sequentially pops all elements from the queue and applies the functor on each object | |
539 | * | |
540 | * \returns number of elements that are consumed | |
541 | * | |
542 | * \note Thread-safe and non-blocking, if functor is thread-safe and non-blocking | |
543 | * */ | |
544 | template <typename Functor> | |
545 | size_t consume_all(Functor & f) | |
546 | { | |
547 | size_t element_count = 0; | |
548 | while (consume_one(f)) | |
549 | element_count += 1; | |
550 | ||
551 | return element_count; | |
552 | } | |
553 | ||
554 | /// \copydoc boost::lockfree::queue::consume_all(Functor & rhs) | |
555 | template <typename Functor> | |
556 | size_t consume_all(Functor const & f) | |
557 | { | |
558 | size_t element_count = 0; | |
559 | while (consume_one(f)) | |
560 | element_count += 1; | |
561 | ||
562 | return element_count; | |
563 | } | |
564 | ||
565 | private: | |
566 | #ifndef BOOST_DOXYGEN_INVOKED | |
567 | atomic<tagged_node_handle> head_; | |
568 | static const int padding_size = BOOST_LOCKFREE_CACHELINE_BYTES - sizeof(tagged_node_handle); | |
569 | char padding1[padding_size]; | |
570 | atomic<tagged_node_handle> tail_; | |
571 | char padding2[padding_size]; | |
572 | ||
573 | pool_t pool; | |
574 | #endif | |
575 | }; | |
576 | ||
577 | } /* namespace lockfree */ | |
578 | } /* namespace boost */ | |
579 | ||
92f5a8d4 TL |
580 | #if defined(BOOST_INTEL) && (BOOST_INTEL_CXX_VERSION > 1000) |
581 | #pragma warning(pop) | |
582 | #endif | |
583 | ||
7c673cae FG |
584 | #if defined(_MSC_VER) |
585 | #pragma warning(pop) | |
586 | #endif | |
587 | ||
588 | #endif /* BOOST_LOCKFREE_FIFO_HPP_INCLUDED */ |