HTML Diff allocation/server.cpp

src/examples/cpp03/allocation/server.cpp		src/examples/cpp11/allocation/server.cpp
⋮		⋮
1	//	1	//
2	//·server.cpp	2	//·server.cpp
3	//·~~~~~~~~~~	3	//·~~~~~~~~~~
4	//	4	//
5	//·Copyright·(c)·2003-2022·Christopher·M.·Kohlhoff·(chris·at·kohlhoff·dot·com)	5	//·Copyright·(c)·2003-2022·Christopher·M.·Kohlhoff·(chris·at·kohlhoff·dot·com)
6	//	6	//
7	//·Distributed·under·the·Boost·Software·License,·Version·1.0.·(See·accompanying	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)	8	//·file·LICENSE_1_0.txt·or·copy·at·http://www.boost.org/LICENSE_1_0.txt)
9	//	9	//
10		10
		11	#include·<array>
11	#include·<cstdlib>	12	#include·<cstdlib>
12	#include·<iostream>	13	#include·<iostream>
13	#include·<boost/aligned_storage.hpp>	14	#include·<memory>
14	#include·<boost/array.hpp>	15	#include·<type_traits>
15	#include·<boost/bind/bind.hpp>	16	#include·<utility>
16	#include·<boost/enable_shared_from_this.hpp>
17	#include·<boost/noncopyable.hpp>
18	#include·<boost/shared_ptr.hpp>
19	#include·"asio.hpp"	17	#include·"asio.hpp"
20		18
21	using·asio::ip::tcp;	19	using·asio::ip::tcp;
22		20
23	//·Class·to·manage·the·memory·to·be·used·for·handler-based·custom·allocation.	21	//·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	22	//·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	23	//·requests.·If·the·memory·is·in·use·when·an·allocation·request·is·made,·the
26	//·allocator·delegates·allocation·to·the·global·heap.	24	//·allocator·delegates·allocation·to·the·global·heap.
27	class·handler_memory	25	class·handler_memory
28	··:·private·boost::noncopyable
29	{	26	{
30	public:	27	public:
31	··handler_memory()	28	··handler_memory()
32	····:·in_use_(false)	29	····:·in_use_(false)
33	··{	30	··{
34	··}	31	··}
35		32
		33	··handler_memory(const·handler_memory&)·=·delete;
		34	··handler_memory&·operator=(const·handler_memory&)·=·delete;
		35
36	··void*·allocate(std::size_t·size)	36	··void*·allocate(std::size_t·size)
37	··{	37	··{
38	····if·(!in_use_·&&·size·<·storage_.size)	38	····if·(!in_use_·&&·size·<·sizeof(storage_))
39	····{	39	····{
40	······in_use_·=·true;	40	······in_use_·=·true;
41	······return·storage_.address();	41	······return·&storage_;
42	····}	42	····}
43	····else	43	····else
44	····{	44	····{
45	······return·::operator·new(size);	45	······return·::operator·new(size);
46	····}	46	····}
47	··}	47	··}
48		48
49	··void·deallocate(void*·pointer)	49	··void·deallocate(void*·pointer)
50	··{	50	··{
51	····if·(pointer·==·storage_.address())	51	····if·(pointer·==·&storage_)
52	····{	52	····{
53	······in_use_·=·false;	53	······in_use_·=·false;
54	····}	54	····}
55	····else	55	····else
56	····{	56	····{
57	······::operator·delete(pointer);	57	······::operator·delete(pointer);
58	····}	58	····}
59	··}	59	··}
60		60
61	private:	61	private:
62	··//·Storage·space·used·for·handler-based·custom·memory·allocation.	62	··//·Storage·space·used·for·handler-based·custom·memory·allocation.
63	··boost::aligned_storage<1024>·storage_;	63	··typename·std::aligned_storage<1024>::type·storage_;
64		64
65	··//·Whether·the·handler-based·custom·allocation·storage·has·been·used.	65	··//·Whether·the·handler-based·custom·allocation·storage·has·been·used.
66	··bool·in_use_;	66	··bool·in_use_;
67	};	67	};
68		68
69	//·The·allocator·to·be·associated·with·the·handler·objects.·This·allocator·only	69	//·The·allocator·to·be·associated·with·the·handler·objects.·This·allocator·only
70	//·needs·to·satisfy·the·C++11·minimal·allocator·requirements,·plus·rebind·when	70	//·needs·to·satisfy·the·C++11·minimal·allocator·requirements.
71	//·targeting·C++03.
72	template·<typename·T>	71	template·<typename·T>
73	class·handler_allocator	72	class·handler_allocator
74	{	73	{
75	public:	74	public:
76	··typedef·T·value_type;	75	··using·value_type·=·T;
77		76
78	··explicit·handler_allocator(handler_memory&·mem)	77	··explicit·handler_allocator(handler_memory&·mem)
79	····:·memory_(mem)	78	····:·memory_(mem)
80	··{	79	··{
81	··}	80	··}
82		81
83	··template·<typename·U>	82	··template·<typename·U>
84	··handler_allocator(const·handler_allocator<U>&·other)	83	··handler_allocator(const·handler_allocator<U>&·other)·noexcept
85	····:·memory_(other.memory_)	84	····:·memory_(other.memory_)
86	··{	85	··{
87	··}	86	··}
88		87
89	··template·<typename·U>	88	··bool·operator==(const·handler_allocator&·other)·const·noexcept
90	··struct·rebind
91	··{
92	····typedef·handler_allocator<U>·other;
93	··};
94
95	··bool·operator==(const·handler_allocator&·other)·const
96	··{	89	··{
97	····return·&memory_·==·&other.memory_;	90	····return·&memory_·==·&other.memory_;
98	··}	91	··}
99		92
100	··bool·operator!=(const·handler_allocator&·other)·const	93	··bool·operator!=(const·handler_allocator&·other)·const·noexcept
101	··{	94	··{
102	····return·&memory_·!=·&other.memory_;	95	····return·&memory_·!=·&other.memory_;
103	··}	96	··}
104		97
105	··T*·allocate(std::size_t·n)·const	98	··T*·allocate(std::size_t·n)·const
106	··{	99	··{
107	····return·static_cast<T>(memory_.allocate(sizeof(T)··n));	100	····return·static_cast<T>(memory_.allocate(sizeof(T)··n));
108	··}	101	··}
109		102
110	··void·deallocate(T·p,·std::size_t·/n*/)·const	103	··void·deallocate(T·p,·std::size_t·/n*/)·const
111	··{	104	··{
112	····return·memory_.deallocate(p);	105	····return·memory_.deallocate(p);
113	··}	106	··}
114		107
115	//private:	108	private:
		109	··template·<typename>·friend·class·handler_allocator;
		110
116	··//·The·underlying·memory.	111	··//·The·underlying·memory.
117	··handler_memory&·memory_;	112	··handler_memory&·memory_;
118	};	113	};
119		114
120	class·session	115	class·session
121	··:·public·boost::enable_shared_from_this<session>	116	··:·public·std::enable_shared_from_this<session>
122	{	117	{
123	public:	118	public:
124	··session(asio::io_context&·io_context)	119	··session(tcp::socket·socket)
125	····:·socket_(io_context)	120	····:·socket_(std::move(socket))
126	··{	121	··{
127	··}	122	··}
128		123
129	··tcp::socket&·socket()	124	··void·start()
130	··{	125	··{
131	····return·socket_;	126	····do_read();
132	··}	127	··}
133		128
134	··void·start()	129	private:
		130	··void·do_read()
135	··{	131	··{
		132	····auto·self(shared_from_this());
136	····socket_.async_read_some(asio::buffer(data_),	133	····socket_.async_read_some(asio::buffer(data_),
137	········asio::bind_allocator(	134	········asio::bind_allocator(
138	··········handler_allocator<int>(handler_memory_),	135	··········handler_allocator<int>(handler_memory_),
139	··········boost::bind(&session::handle_read,	136	··········[this,·self](std::error_code·ec,·std::size_t·length)
140	············shared_from_this(),	137	··········{
141	············asio::placeholders::error,	138	············if·(!ec)
142	············asio::placeholders::bytes_transferred)));	139	············{
143	··}	140	··············do_write(length);
144		141	············}
145	··void·handle_read(const·asio::error_code&·error,	142	··········}));
146	······size_t·bytes_transferred)
147	··{
148	····if·(!error)
149	····{
150	······asio::async_write(socket_,
151	··········asio::buffer(data_,·bytes_transferred),
152	··········asio::bind_allocator(
153	············handler_allocator<int>(handler_memory_),
154	············boost::bind(&session::handle_write,
155	··············shared_from_this(),
156	··············asio::placeholders::error)));
157	····}
158	··}	143	··}
159		144
160	··void·handle_write(const·asio::error_code&·error)	145	··void·do_write(std::size_t·length)
161	··{	146	··{
162	····if·(!error)	147	····auto·self(shared_from_this());
163	····{	148	····asio::async_write(socket_,·asio::buffer(data_,·length),
164	······socket_.async_read_some(asio::buffer(data_),	149	········asio::bind_allocator(
165	··········asio::bind_allocator(	150	··········handler_allocator<int>(handler_memory_),
166	············handler_allocator<int>(handler_memory_),	151	··········[this,·self](std::error_code·ec,·std::size_t·/length/)
167	············boost::bind(&session::handle_read,	152	··········{
168	··············shared_from_this(),	153	············if·(!ec)
169	··············asio::placeholders::error,	154	············{
170	··············asio::placeholders::bytes_transferred)));	155	··············do_read();
171	····}	156	············}
		157	··········}));
172	··}	158	··}
173		159
174	private:
175	··//·The·socket·used·to·communicate·with·the·client.	160	··//·The·socket·used·to·communicate·with·the·client.
176	··tcp::socket·socket_;	161	··tcp::socket·socket_;
177		162
178	··//·Buffer·used·to·store·data·received·from·the·client.	163	··//·Buffer·used·to·store·data·received·from·the·client.
179	··boost::array<char,·1024>·data_;	164	··std::array<char,·1024>·data_;
180		165
181	··//·The·memory·to·use·for·handler-based·custom·memory·allocation.	166	··//·The·memory·to·use·for·handler-based·custom·memory·allocation.
182	··handler_memory·handler_memory_;	167	··handler_memory·handler_memory_;
183	};	168	};
184		169
185	typedef·boost::shared_ptr<session>·session_ptr;
186
187	class·server	170	class·server
188	{	171	{
189	public:	172	public:
190	··server(asio::io_context&·io_context,·short·port)	173	··server(asio::io_context&·io_context,·short·port)
191	····:·io_context_(io_context),	174	····:·acceptor_(io_context,·tcp::endpoint(tcp::v4(),·port))
192	······acceptor_(io_context,·tcp::endpoint(tcp::v4(),·port))
193	··{	175	··{
194	····session_ptr·new_session(new·session(io_context_));	176	····do_accept();
195	····acceptor_.async_accept(new_session->socket(),
196	········boost::bind(&server::handle_accept,·this,·new_session,
197	··········asio::placeholders::error));
198	··}	177	··}
199		178
200	··void·handle_accept(session_ptr·new_session,	179	private:
201	······const·asio::error_code&·error)	180	··void·do_accept()
202	··{	181	··{
203	····if·(!error)	182	····acceptor_.async_accept(
204	····{	183	········[this](std::error_code·ec,·tcp::socket·socket)
205	······new_session->start();	184	········{
206	····}	185	··········if·(!ec)
		186	··········{
		187	············std::make_shared<session>(std::move(socket))->start();
		188	··········}
207		189
208	····new_session.reset(new·session(io_context_));	190	··········do_accept();
209	····acceptor_.async_accept(new_session->socket(),	191	········});
210	········boost::bind(&server::handle_accept,·this,·new_session,
211	··········asio::placeholders::error));
212	··}	192	··}
213		193
214	private:
215	··asio::io_context&·io_context_;
216	··tcp::acceptor·acceptor_;	194	··tcp::acceptor·acceptor_;
217	};	195	};
218		196
219	int·main(int·argc,·char*·argv[])	197	int·main(int·argc,·char*·argv[])
220	{	198	{
221	··try	199	··try
222	··{	200	··{
223	····if·(argc·!=·2)	201	····if·(argc·!=·2)
224	····{	202	····{
225	······std::cerr·<<·"Usage:·server·<port>\n";	203	······std::cerr·<<·"Usage:·server·<port>\n";
226	······return·1;	204	······return·1;
227	····}	205	····}
228		206
229	····asio::io_context·io_context;	207	····asio::io_context·io_context;
230		208	····server·s(io_context,·std::atoi(argv[1]));
231	····using·namespace·std;·//·For·atoi.
232	····server·s(io_context,·atoi(argv[1]));
233
234	····io_context.run();	209	····io_context.run();
235	··}	210	··}
236	··catch·(std::exception&·e)	211	··catch·(std::exception&·e)
237	··{	212	··{
238	····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n";	213	····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n";
239	··}	214	··}
240		215
241	··return·0;	216	··return·0;
242	}	217	}