1 //
2 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
3 //
4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // Official repository: https://github.com/boostorg/beast
8 //
9
10 #ifndef BOOST_BEAST_CORE_IMPL_ASYNC_BASE_HPP
11 #define BOOST_BEAST_CORE_IMPL_ASYNC_BASE_HPP
12
13 #include <boost/core/exchange.hpp>
14
15 namespace boost {
16 namespace beast {
17
18 namespace detail {
19
20 template<class State, class Allocator>
21 struct allocate_stable_state final
22 : stable_base
23 , boost::empty_value<Allocator>
24 {
25 State value;
26
27 template<class... Args>
28 explicit
allocate_stable_stateboost::beast::detail::allocate_stable_state29 allocate_stable_state(
30 Allocator const& alloc,
31 Args&&... args)
32 : boost::empty_value<Allocator>(
33 boost::empty_init_t{}, alloc)
34 , value{std::forward<Args>(args)...}
35 {
36 }
37
destroyboost::beast::detail::allocate_stable_state38 void destroy() override
39 {
40 using A = typename allocator_traits<
41 Allocator>::template rebind_alloc<
42 allocate_stable_state>;
43
44 A a(this->get());
45 auto* p = this;
46 p->~allocate_stable_state();
47 a.deallocate(p, 1);
48 }
49 };
50
51 } // detail
52
53 template<
54 class Handler,
55 class Executor1,
56 class Allocator,
57 class Function>
58 boost::asio::asio_handler_invoke_is_deprecated
asio_handler_invoke(Function && f,async_base<Handler,Executor1,Allocator> * p)59 asio_handler_invoke(
60 Function&& f,
61 async_base<Handler, Executor1, Allocator>* p)
62 {
63 using boost::asio::asio_handler_invoke;
64 return asio_handler_invoke(f,
65 p->get_legacy_handler_pointer());
66 }
67
68 template<
69 class Handler,
70 class Executor1,
71 class Allocator>
72 boost::asio::asio_handler_allocate_is_deprecated
asio_handler_allocate(std::size_t size,async_base<Handler,Executor1,Allocator> * p)73 asio_handler_allocate(
74 std::size_t size,
75 async_base<Handler, Executor1, Allocator>* p)
76 {
77 using boost::asio::asio_handler_allocate;
78 return asio_handler_allocate(size,
79 p->get_legacy_handler_pointer());
80 }
81
82 template<
83 class Handler,
84 class Executor1,
85 class Allocator>
86 boost::asio::asio_handler_deallocate_is_deprecated
asio_handler_deallocate(void * mem,std::size_t size,async_base<Handler,Executor1,Allocator> * p)87 asio_handler_deallocate(
88 void* mem, std::size_t size,
89 async_base<Handler, Executor1, Allocator>* p)
90 {
91 using boost::asio::asio_handler_deallocate;
92 return asio_handler_deallocate(mem, size,
93 p->get_legacy_handler_pointer());
94 }
95
96 template<
97 class Handler,
98 class Executor1,
99 class Allocator>
100 bool
asio_handler_is_continuation(async_base<Handler,Executor1,Allocator> * p)101 asio_handler_is_continuation(
102 async_base<Handler, Executor1, Allocator>* p)
103 {
104 using boost::asio::asio_handler_is_continuation;
105 return asio_handler_is_continuation(
106 p->get_legacy_handler_pointer());
107 }
108
109 template<
110 class State,
111 class Handler,
112 class Executor1,
113 class Allocator,
114 class... Args>
115 State&
allocate_stable(stable_async_base<Handler,Executor1,Allocator> & base,Args &&...args)116 allocate_stable(
117 stable_async_base<
118 Handler, Executor1, Allocator>& base,
119 Args&&... args)
120 {
121 using allocator_type = typename stable_async_base<
122 Handler, Executor1, Allocator>::allocator_type;
123 using state = detail::allocate_stable_state<
124 State, allocator_type>;
125 using A = typename detail::allocator_traits<
126 allocator_type>::template rebind_alloc<state>;
127
128 struct deleter
129 {
130 allocator_type alloc;
131 state* ptr;
132
133 ~deleter()
134 {
135 if(ptr)
136 {
137 A a(alloc);
138 a.deallocate(ptr, 1);
139 }
140 }
141 };
142
143 A a(base.get_allocator());
144 deleter d{base.get_allocator(), a.allocate(1)};
145 ::new(static_cast<void*>(d.ptr))
146 state(d.alloc, std::forward<Args>(args)...);
147 d.ptr->next_ = base.list_;
148 base.list_ = d.ptr;
149 return boost::exchange(d.ptr, nullptr)->value;
150 }
151
152 } // beast
153 } // boost
154
155 #endif
156