1 | // |
---|---|
2 | // detail/thread_info_base.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_DETAIL_THREAD_INFO_BASE_HPP |
12 | #define BOOST_ASIO_DETAIL_THREAD_INFO_BASE_HPP |
13 | |
14 | #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
15 | # pragma once |
16 | #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
17 | |
18 | #include <climits> |
19 | #include <cstddef> |
20 | #include <boost/asio/detail/noncopyable.hpp> |
21 | |
22 | #include <boost/asio/detail/push_options.hpp> |
23 | |
24 | namespace boost { |
25 | namespace asio { |
26 | namespace detail { |
27 | |
28 | class thread_info_base |
29 | : private noncopyable |
30 | { |
31 | public: |
32 | thread_info_base() |
33 | : reusable_memory_(0) |
34 | { |
35 | } |
36 | |
37 | ~thread_info_base() |
38 | { |
39 | if (reusable_memory_) |
40 | ::operator delete(reusable_memory_); |
41 | } |
42 | |
43 | static void* allocate(thread_info_base* this_thread, std::size_t size) |
44 | { |
45 | if (this_thread && this_thread->reusable_memory_) |
46 | { |
47 | void* const pointer = this_thread->reusable_memory_; |
48 | this_thread->reusable_memory_ = 0; |
49 | |
50 | unsigned char* const mem = static_cast<unsigned char*>(pointer); |
51 | if (static_cast<std::size_t>(mem[0]) >= size) |
52 | { |
53 | mem[size] = mem[0]; |
54 | return pointer; |
55 | } |
56 | |
57 | ::operator delete(pointer); |
58 | } |
59 | |
60 | void* const pointer = ::operator new(size + 1); |
61 | unsigned char* const mem = static_cast<unsigned char*>(pointer); |
62 | mem[size] = (size <= UCHAR_MAX) ? static_cast<unsigned char>(size) : 0; |
63 | return pointer; |
64 | } |
65 | |
66 | static void deallocate(thread_info_base* this_thread, |
67 | void* pointer, std::size_t size) |
68 | { |
69 | if (size <= UCHAR_MAX) |
70 | { |
71 | if (this_thread && this_thread->reusable_memory_ == 0) |
72 | { |
73 | unsigned char* const mem = static_cast<unsigned char*>(pointer); |
74 | mem[0] = mem[size]; |
75 | this_thread->reusable_memory_ = pointer; |
76 | return; |
77 | } |
78 | } |
79 | |
80 | ::operator delete(pointer); |
81 | } |
82 | |
83 | private: |
84 | void* reusable_memory_; |
85 | }; |
86 | |
87 | } // namespace detail |
88 | } // namespace asio |
89 | } // namespace boost |
90 | |
91 | #include <boost/asio/detail/pop_options.hpp> |
92 | |
93 | #endif // BOOST_ASIO_DETAIL_THREAD_INFO_BASE_HPP |
94 |