| // |
| // detail/object_pool.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2014 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| // |
| |
| #ifndef ASIO_DETAIL_OBJECT_POOL_HPP |
| #define ASIO_DETAIL_OBJECT_POOL_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include "asio/detail/noncopyable.hpp" |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace detail { |
| |
| template <typename Object> |
| class object_pool; |
| |
| class object_pool_access |
| { |
| public: |
| template <typename Object> |
| static Object* create() |
| { |
| return new Object; |
| } |
| |
| template <typename Object> |
| static void destroy(Object* o) |
| { |
| delete o; |
| } |
| |
| template <typename Object> |
| static Object*& next(Object* o) |
| { |
| return o->next_; |
| } |
| |
| template <typename Object> |
| static Object*& prev(Object* o) |
| { |
| return o->prev_; |
| } |
| }; |
| |
| template <typename Object> |
| class object_pool |
| : private noncopyable |
| { |
| public: |
| // Constructor. |
| object_pool() |
| : live_list_(0), |
| free_list_(0) |
| { |
| } |
| |
| // Destructor destroys all objects. |
| ~object_pool() |
| { |
| destroy_list(live_list_); |
| destroy_list(free_list_); |
| } |
| |
| // Get the object at the start of the live list. |
| Object* first() |
| { |
| return live_list_; |
| } |
| |
| // Allocate a new object. |
| Object* alloc() |
| { |
| Object* o = free_list_; |
| if (o) |
| free_list_ = object_pool_access::next(free_list_); |
| else |
| o = object_pool_access::create<Object>(); |
| |
| object_pool_access::next(o) = live_list_; |
| object_pool_access::prev(o) = 0; |
| if (live_list_) |
| object_pool_access::prev(live_list_) = o; |
| live_list_ = o; |
| |
| return o; |
| } |
| |
| // Free an object. Moves it to the free list. No destructors are run. |
| void free(Object* o) |
| { |
| if (live_list_ == o) |
| live_list_ = object_pool_access::next(o); |
| |
| if (object_pool_access::prev(o)) |
| { |
| object_pool_access::next(object_pool_access::prev(o)) |
| = object_pool_access::next(o); |
| } |
| |
| if (object_pool_access::next(o)) |
| { |
| object_pool_access::prev(object_pool_access::next(o)) |
| = object_pool_access::prev(o); |
| } |
| |
| object_pool_access::next(o) = free_list_; |
| object_pool_access::prev(o) = 0; |
| free_list_ = o; |
| } |
| |
| private: |
| // Helper function to destroy all elements in a list. |
| void destroy_list(Object* list) |
| { |
| while (list) |
| { |
| Object* o = list; |
| list = object_pool_access::next(o); |
| object_pool_access::destroy(o); |
| } |
| } |
| |
| // The list of live objects. |
| Object* live_list_; |
| |
| // The free list. |
| Object* free_list_; |
| }; |
| |
| } // namespace detail |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #endif // ASIO_DETAIL_OBJECT_POOL_HPP |