5 // Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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)
13 #include <boost/aligned_storage.hpp>
14 #include <boost/array.hpp>
15 #include <boost/bind.hpp>
16 #include <boost/enable_shared_from_this.hpp>
17 #include <boost/noncopyable.hpp>
18 #include <boost/shared_ptr.hpp>
19 #include <boost/asio.hpp>
21 using boost::asio::ip::tcp
;
23 // Class to manage the memory to be used for handler-based custom allocation.
24 // It contains a single block of memory which may be returned for allocation
25 // requests. If the memory is in use when an allocation request is made, the
26 // allocator delegates allocation to the global heap.
27 class handler_allocator
28 : private boost::noncopyable
36 void* allocate(std::size_t size
)
38 if (!in_use_
&& size
< storage_
.size
)
41 return storage_
.address();
45 return ::operator new(size
);
49 void deallocate(void* pointer
)
51 if (pointer
== storage_
.address())
57 ::operator delete(pointer
);
62 // Storage space used for handler-based custom memory allocation.
63 boost::aligned_storage
<1024> storage_
;
65 // Whether the handler-based custom allocation storage has been used.
69 // Wrapper class template for handler objects to allow handler memory
70 // allocation to be customised. Calls to operator() are forwarded to the
71 // encapsulated handler.
72 template <typename Handler
>
73 class custom_alloc_handler
76 custom_alloc_handler(handler_allocator
& a
, Handler h
)
82 template <typename Arg1
>
83 void operator()(Arg1 arg1
)
88 template <typename Arg1
, typename Arg2
>
89 void operator()(Arg1 arg1
, Arg2 arg2
)
94 friend void* asio_handler_allocate(std::size_t size
,
95 custom_alloc_handler
<Handler
>* this_handler
)
97 return this_handler
->allocator_
.allocate(size
);
100 friend void asio_handler_deallocate(void* pointer
, std::size_t /*size*/,
101 custom_alloc_handler
<Handler
>* this_handler
)
103 this_handler
->allocator_
.deallocate(pointer
);
107 handler_allocator
& allocator_
;
111 // Helper function to wrap a handler object to add custom allocation.
112 template <typename Handler
>
113 inline custom_alloc_handler
<Handler
> make_custom_alloc_handler(
114 handler_allocator
& a
, Handler h
)
116 return custom_alloc_handler
<Handler
>(a
, h
);
120 : public boost::enable_shared_from_this
<session
>
123 session(boost::asio::io_service
& io_service
)
124 : socket_(io_service
)
128 tcp::socket
& socket()
135 socket_
.async_read_some(boost::asio::buffer(data_
),
136 make_custom_alloc_handler(allocator_
,
137 boost::bind(&session::handle_read
,
139 boost::asio::placeholders::error
,
140 boost::asio::placeholders::bytes_transferred
)));
143 void handle_read(const boost::system::error_code
& error
,
144 size_t bytes_transferred
)
148 boost::asio::async_write(socket_
,
149 boost::asio::buffer(data_
, bytes_transferred
),
150 make_custom_alloc_handler(allocator_
,
151 boost::bind(&session::handle_write
,
153 boost::asio::placeholders::error
)));
157 void handle_write(const boost::system::error_code
& error
)
161 socket_
.async_read_some(boost::asio::buffer(data_
),
162 make_custom_alloc_handler(allocator_
,
163 boost::bind(&session::handle_read
,
165 boost::asio::placeholders::error
,
166 boost::asio::placeholders::bytes_transferred
)));
171 // The socket used to communicate with the client.
174 // Buffer used to store data received from the client.
175 boost::array
<char, 1024> data_
;
177 // The allocator to use for handler-based custom memory allocation.
178 handler_allocator allocator_
;
181 typedef boost::shared_ptr
<session
> session_ptr
;
186 server(boost::asio::io_service
& io_service
, short port
)
187 : io_service_(io_service
),
188 acceptor_(io_service
, tcp::endpoint(tcp::v4(), port
))
190 session_ptr
new_session(new session(io_service_
));
191 acceptor_
.async_accept(new_session
->socket(),
192 boost::bind(&server::handle_accept
, this, new_session
,
193 boost::asio::placeholders::error
));
196 void handle_accept(session_ptr new_session
,
197 const boost::system::error_code
& error
)
201 new_session
->start();
204 new_session
.reset(new session(io_service_
));
205 acceptor_
.async_accept(new_session
->socket(),
206 boost::bind(&server::handle_accept
, this, new_session
,
207 boost::asio::placeholders::error
));
211 boost::asio::io_service
& io_service_
;
212 tcp::acceptor acceptor_
;
215 int main(int argc
, char* argv
[])
221 std::cerr
<< "Usage: server <port>\n";
225 boost::asio::io_service io_service
;
227 using namespace std
; // For atoi.
228 server
s(io_service
, atoi(argv
[1]));
232 catch (std::exception
& e
)
234 std::cerr
<< "Exception: " << e
.what() << "\n";