1//
2// handler_alloc_hook.hpp
3// ~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6//
7// Distributed under the Boost Software License, Version 1.0. (See accompanying
8// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9//
10
11#ifndef BOOST_ASIO_HANDLER_ALLOC_HOOK_HPP
12#define BOOST_ASIO_HANDLER_ALLOC_HOOK_HPP
13
14#if defined(_MSC_VER) && (_MSC_VER >= 1200)
15# pragma once
16#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
17
18#include <boost/asio/detail/config.hpp>
19#include <cstddef>
20
21#include <boost/asio/detail/push_options.hpp>
22
23namespace boost {
24namespace asio {
25
26/// Default allocation function for handlers.
27/**
28 * Asynchronous operations may need to allocate temporary objects. Since
29 * asynchronous operations have a handler function object, these temporary
30 * objects can be said to be associated with the handler.
31 *
32 * Implement asio_handler_allocate and asio_handler_deallocate for your own
33 * handlers to provide custom allocation for these temporary objects.
34 *
35 * The default implementation of these allocation hooks uses <tt>::operator
36 * new</tt> and <tt>::operator delete</tt>.
37 *
38 * @note All temporary objects associated with a handler will be deallocated
39 * before the upcall to the handler is performed. This allows the same memory to
40 * be reused for a subsequent asynchronous operation initiated by the handler.
41 *
42 * @par Example
43 * @code
44 * class my_handler;
45 *
46 * void* asio_handler_allocate(std::size_t size, my_handler* context)
47 * {
48 * return ::operator new(size);
49 * }
50 *
51 * void asio_handler_deallocate(void* pointer, std::size_t size,
52 * my_handler* context)
53 * {
54 * ::operator delete(pointer);
55 * }
56 * @endcode
57 */
58BOOST_ASIO_DECL void* asio_handler_allocate(
59 std::size_t size, ...);
60
61/// Default deallocation function for handlers.
62/**
63 * Implement asio_handler_allocate and asio_handler_deallocate for your own
64 * handlers to provide custom allocation for the associated temporary objects.
65 *
66 * The default implementation of these allocation hooks uses <tt>::operator
67 * new</tt> and <tt>::operator delete</tt>.
68 *
69 * @sa asio_handler_allocate.
70 */
71BOOST_ASIO_DECL void asio_handler_deallocate(
72 void* pointer, std::size_t size, ...);
73
74} // namespace asio
75} // namespace boost
76
77#include <boost/asio/detail/pop_options.hpp>
78
79#if defined(BOOST_ASIO_HEADER_ONLY)
80# include <boost/asio/impl/handler_alloc_hook.ipp>
81#endif // defined(BOOST_ASIO_HEADER_ONLY)
82
83#endif // BOOST_ASIO_HANDLER_ALLOC_HOOK_HPP
84