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Diffstat (limited to 'external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/yqueue.hpp')
| -rw-r--r-- | external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/yqueue.hpp | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/yqueue.hpp b/external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/yqueue.hpp deleted file mode 100644 index bd42b8a6..00000000 --- a/external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/yqueue.hpp +++ /dev/null @@ -1,205 +0,0 @@ -/* - Copyright (c) 2007-2015 Contributors as noted in the AUTHORS file - - This file is part of libzmq, the ZeroMQ core engine in C++. - - libzmq is free software; you can redistribute it and/or modify it under - the terms of the GNU Lesser General Public License (LGPL) as published - by the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. - - As a special exception, the Contributors give you permission to link - this library with independent modules to produce an executable, - regardless of the license terms of these independent modules, and to - copy and distribute the resulting executable under terms of your choice, - provided that you also meet, for each linked independent module, the - terms and conditions of the license of that module. An independent - module is a module which is not derived from or based on this library. - If you modify this library, you must extend this exception to your - version of the library. - - libzmq is distributed in the hope that it will be useful, but WITHOUT - ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public - License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. -*/ - -#ifndef __ZMQ_YQUEUE_HPP_INCLUDED__ -#define __ZMQ_YQUEUE_HPP_INCLUDED__ - -#include <stdlib.h> -#include <stddef.h> - -#include "err.hpp" -#include "atomic_ptr.hpp" - -namespace zmq -{ - - // yqueue is an efficient queue implementation. The main goal is - // to minimise number of allocations/deallocations needed. Thus yqueue - // allocates/deallocates elements in batches of N. - // - // yqueue allows one thread to use push/back function and another one - // to use pop/front functions. However, user must ensure that there's no - // pop on the empty queue and that both threads don't access the same - // element in unsynchronised manner. - // - // T is the type of the object in the queue. - // N is granularity of the queue (how many pushes have to be done till - // actual memory allocation is required). - - template <typename T, int N> class yqueue_t - { - public: - - // Create the queue. - inline yqueue_t () - { - begin_chunk = (chunk_t*) malloc (sizeof (chunk_t)); - alloc_assert (begin_chunk); - begin_pos = 0; - back_chunk = NULL; - back_pos = 0; - end_chunk = begin_chunk; - end_pos = 0; - } - - // Destroy the queue. - inline ~yqueue_t () - { - while (true) { - if (begin_chunk == end_chunk) { - free (begin_chunk); - break; - } - chunk_t *o = begin_chunk; - begin_chunk = begin_chunk->next; - free (o); - } - - chunk_t *sc = spare_chunk.xchg (NULL); - free (sc); - } - - // Returns reference to the front element of the queue. - // If the queue is empty, behaviour is undefined. - inline T &front () - { - return begin_chunk->values [begin_pos]; - } - - // Returns reference to the back element of the queue. - // If the queue is empty, behaviour is undefined. - inline T &back () - { - return back_chunk->values [back_pos]; - } - - // Adds an element to the back end of the queue. - inline void push () - { - back_chunk = end_chunk; - back_pos = end_pos; - - if (++end_pos != N) - return; - - chunk_t *sc = spare_chunk.xchg (NULL); - if (sc) { - end_chunk->next = sc; - sc->prev = end_chunk; - } else { - end_chunk->next = (chunk_t*) malloc (sizeof (chunk_t)); - alloc_assert (end_chunk->next); - end_chunk->next->prev = end_chunk; - } - end_chunk = end_chunk->next; - end_pos = 0; - } - - // Removes element from the back end of the queue. In other words - // it rollbacks last push to the queue. Take care: Caller is - // responsible for destroying the object being unpushed. - // The caller must also guarantee that the queue isn't empty when - // unpush is called. It cannot be done automatically as the read - // side of the queue can be managed by different, completely - // unsynchronised thread. - inline void unpush () - { - // First, move 'back' one position backwards. - if (back_pos) - --back_pos; - else { - back_pos = N - 1; - back_chunk = back_chunk->prev; - } - - // Now, move 'end' position backwards. Note that obsolete end chunk - // is not used as a spare chunk. The analysis shows that doing so - // would require free and atomic operation per chunk deallocated - // instead of a simple free. - if (end_pos) - --end_pos; - else { - end_pos = N - 1; - end_chunk = end_chunk->prev; - free (end_chunk->next); - end_chunk->next = NULL; - } - } - - // Removes an element from the front end of the queue. - inline void pop () - { - if (++ begin_pos == N) { - chunk_t *o = begin_chunk; - begin_chunk = begin_chunk->next; - begin_chunk->prev = NULL; - begin_pos = 0; - - // 'o' has been more recently used than spare_chunk, - // so for cache reasons we'll get rid of the spare and - // use 'o' as the spare. - chunk_t *cs = spare_chunk.xchg (o); - free (cs); - } - } - - private: - - // Individual memory chunk to hold N elements. - struct chunk_t - { - T values [N]; - chunk_t *prev; - chunk_t *next; - }; - - // Back position may point to invalid memory if the queue is empty, - // while begin & end positions are always valid. Begin position is - // accessed exclusively be queue reader (front/pop), while back and - // end positions are accessed exclusively by queue writer (back/push). - chunk_t *begin_chunk; - int begin_pos; - chunk_t *back_chunk; - int back_pos; - chunk_t *end_chunk; - int end_pos; - - // People are likely to produce and consume at similar rates. In - // this scenario holding onto the most recently freed chunk saves - // us from having to call malloc/free. - atomic_ptr_t<chunk_t> spare_chunk; - - // Disable copying of yqueue. - yqueue_t (const yqueue_t&); - const yqueue_t &operator = (const yqueue_t&); - }; - -} - -#endif |