src/examples/cpp03/timeouts/blocking_token_tcp_client.cpp | src/examples/cpp11/timeouts/blocking_token_tcp_client.cpp |
⋮ | ⋮ |
1 | // | 1 | // |
2 | //·blocking_token_tcp_client.cpp | 2 | //·blocking_token_tcp_client.cpp |
3 | //·~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | 3 | //·~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
4 | // | 4 | // |
5 | //·Copyright·(c)·2003-2018·Christopher·M.·Kohlhoff·(chris·at·kohlhoff·dot·com) | 5 | //·Copyright·(c)·2003-2018·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·"asio/connect.hpp" | 11 | #include·"asio/connect.hpp" |
12 | #include·"asio/io_context.hpp" | 12 | #include·"asio/io_context.hpp" |
13 | #include·"asio/ip/tcp.hpp" | 13 | #include·"asio/ip/tcp.hpp" |
14 | #include·"asio/read_until.hpp" | 14 | #include·"asio/read_until.hpp" |
15 | #include·"asio/streambuf.hpp" | 15 | #include·"asio/streambuf.hpp" |
16 | #include·"asio/system_error.hpp" | 16 | #include·"asio/system_error.hpp" |
17 | #include·"asio/write.hpp" | 17 | #include·"asio/write.hpp" |
18 | #include·<cstdlib> | 18 | #include·<cstdlib> |
19 | #include·<iostream> | 19 | #include·<iostream> |
20 | #include·<memory> | 20 | #include·<memory> |
21 | #include·<string> | 21 | #include·<string> |
22 | | 22 | |
23 | using·asio::ip::tcp; | 23 | using·asio::ip::tcp; |
24 | | 24 | |
25 | //---------------------------------------------------------------------- | 25 | //---------------------------------------------------------------------- |
26 | | 26 | |
27 | //·A·custom·completion·token·that·makes·asynchronous·operations·behave·as | 27 | //·A·custom·completion·token·that·makes·asynchronous·operations·behave·as |
28 | //·though·they·are·blocking·calls·with·a·timeout. | 28 | //·though·they·are·blocking·calls·with·a·timeout. |
29 | struct·close_after | 29 | struct·close_after |
30 | { | 30 | { |
31 | ··close_after(asio::chrono::steady_clock::duration·t,·tcp::socket&·s) | 31 | ··close_after(std::chrono::steady_clock::duration·t,·tcp::socket&·s) |
32 | ····:·timeout_(t),·socket_(s) | 32 | ····:·timeout_(t),·socket_(s) |
33 | ··{ | 33 | ··{ |
34 | ··} | 34 | ··} |
35 | | 35 | |
36 | ··//·The·maximum·time·to·wait·for·an·asynchronous·operation·to·complete. | 36 | ··//·The·maximum·time·to·wait·for·an·asynchronous·operation·to·complete. |
37 | ··asio::chrono::steady_clock::duration·timeout_; | 37 | ··std::chrono::steady_clock::duration·timeout_; |
38 | | 38 | |
39 | ··//·The·socket·to·be·closed·if·the·operation·does·not·complete·in·time. | 39 | ··//·The·socket·to·be·closed·if·the·operation·does·not·complete·in·time. |
40 | ··tcp::socket&·socket_; | 40 | ··tcp::socket&·socket_; |
41 | }; | 41 | }; |
42 | | 42 | |
43 | namespace·asio·{ | 43 | namespace·asio·{ |
44 | | 44 | |
45 | //·The·async_result·template·is·specialised·to·allow·the·close_after·token·to | 45 | //·The·async_result·template·is·specialised·to·allow·the·close_after·token·to |
46 | //·be·used·with·asynchronous·operations·that·have·a·completion·signature·of | 46 | //·be·used·with·asynchronous·operations·that·have·a·completion·signature·of |
47 | //·void(error_code,·T).·Generalising·this·for·all·completion·signature·forms·is | 47 | //·void(error_code,·T).·Generalising·this·for·all·completion·signature·forms·is |
48 | //·left·as·an·exercise·for·the·reader. | 48 | //·left·as·an·exercise·for·the·reader. |
49 | template·<typename·T> | 49 | template·<typename·T> |
50 | class·async_result<close_after,·void(asio::error_code,·T)> | 50 | class·async_result<close_after,·void(std::error_code,·T)> |
51 | { | 51 | { |
52 | public: | 52 | public: |
53 | ··//·An·asynchronous·operation's·initiating·function·automatically·creates·an | 53 | ··//·An·asynchronous·operation's·initiating·function·automatically·creates·an |
54 | ··//·completion_handler_type·object·from·the·token.·This·function·object·is | 54 | ··//·completion_handler_type·object·from·the·token.·This·function·object·is |
55 | ··//·then·called·on·completion·of·the·asynchronous·operation. | 55 | ··//·then·called·on·completion·of·the·asynchronous·operation. |
56 | ··class·completion_handler_type | 56 | ··class·completion_handler_type |
57 | ··{ | 57 | ··{ |
58 | ··public: | 58 | ··public: |
59 | ····completion_handler_type(const·close_after&·token) | 59 | ····completion_handler_type(const·close_after&·token) |
60 | ······:·token_(token) | 60 | ······:·token_(token) |
61 | ····{ | 61 | ····{ |
62 | ····} | 62 | ····} |
63 | | 63 | |
64 | ····void·operator()(asio::error_code·ec,·T·t) | 64 | ····void·operator()(const·std::error_code&·error,·T·t) |
65 | ····{ | 65 | ····{ |
66 | ······*ec_·=·ec; | 66 | ······*error_·=·error; |
67 | ······*t_·=·t; | 67 | ······*t_·=·t; |
68 | ····} | 68 | ····} |
69 | | 69 | |
70 | ··private: | 70 | ··private: |
71 | ····friend·class·async_result; | 71 | ····friend·class·async_result; |
72 | ····close_after·token_; | 72 | ····close_after·token_; |
73 | ····asio::error_code*·ec_; | 73 | ····std::error_code*·error_; |
74 | ····T*·t_; | 74 | ····T*·t_; |
75 | ··}; | 75 | ··}; |
76 | | 76 | |
77 | ··//·The·async_result·constructor·associates·the·completion·handler·object·with | 77 | ··//·The·async_result·constructor·associates·the·completion·handler·object·with |
78 | ··//·the·result·of·the·initiating·function. | 78 | ··//·the·result·of·the·initiating·function. |
79 | ··explicit·async_result(completion_handler_type&·h) | 79 | ··explicit·async_result(completion_handler_type&·h) |
80 | ····:·timeout_(h.token_.timeout_), | 80 | ····:·timeout_(h.token_.timeout_), |
81 | ······socket_(h.token_.socket_) | 81 | ······socket_(h.token_.socket_) |
82 | ··{ | 82 | ··{ |
83 | ····h.ec_·=·&ec_; | 83 | ····h.error_·=·&error_; |
84 | ····h.t_·=·&t_; | 84 | ····h.t_·=·&t_; |
85 | ··} | 85 | ··} |
86 | | 86 | |
87 | ··//·The·return_type·typedef·determines·the·result·type·of·the·asynchronous | 87 | ··//·The·return_type·typedef·determines·the·result·type·of·the·asynchronous |
88 | ··//·operation's·initiating·function. | 88 | ··//·operation's·initiating·function. |
89 | ··typedef·T·return_type; | 89 | ··typedef·T·return_type; |
90 | | 90 | |
91 | ··//·The·get()·function·is·used·to·obtain·the·result·of·the·asynchronous | 91 | ··//·The·get()·function·is·used·to·obtain·the·result·of·the·asynchronous |
92 | ··//·operation's·initiating·function.·For·the·close_after·completion·token,·we | 92 | ··//·operation's·initiating·function.·For·the·close_after·completion·token,·we |
93 | ··//·use·this·function·to·run·the·io_context·until·the·operation·is·complete. | 93 | ··//·use·this·function·to·run·the·io_context·until·the·operation·is·complete. |
94 | ··return_type·get() | 94 | ··return_type·get() |
95 | ··{ | 95 | ··{ |
96 | ····asio::io_context&·io_context·=·socket_.get_executor().context(); | 96 | ····asio::io_context&·io_context·=·socket_.get_executor().context(); |
97 | | 97 | |
98 | ····//·Restart·the·io_context,·as·it·may·have·been·left·in·the·"stopped"·state | 98 | ····//·Restart·the·io_context,·as·it·may·have·been·left·in·the·"stopped"·state |
99 | ····//·by·a·previous·operation. | 99 | ····//·by·a·previous·operation. |
100 | ····io_context.restart(); | 100 | ····io_context.restart(); |
101 | | 101 | |
102 | ····//·Block·until·the·asynchronous·operation·has·completed,·or·timed·out.·If | 102 | ····//·Block·until·the·asynchronous·operation·has·completed,·or·timed·out.·If |
103 | ····//·the·pending·asynchronous·operation·is·a·composed·operation,·the·deadline | 103 | ····//·the·pending·asynchronous·operation·is·a·composed·operation,·the·deadline |
104 | ····//·applies·to·the·entire·operation,·rather·than·individual·operations·on | 104 | ····//·applies·to·the·entire·operation,·rather·than·individual·operations·on |
105 | ····//·the·socket. | 105 | ····//·the·socket. |
106 | ····io_context.run_for(timeout_); | 106 | ····io_context.run_for(timeout_); |
107 | | 107 | |
108 | ····//·If·the·asynchronous·operation·completed·successfully·then·the·io_context | 108 | ····//·If·the·asynchronous·operation·completed·successfully·then·the·io_context |
109 | ····//·would·have·been·stopped·due·to·running·out·of·work.·If·it·was·not | 109 | ····//·would·have·been·stopped·due·to·running·out·of·work.·If·it·was·not |
110 | ····//·stopped,·then·the·io_context::run_for·call·must·have·timed·out·and·the | 110 | ····//·stopped,·then·the·io_context::run_for·call·must·have·timed·out·and·the |
111 | ····//·operation·is·still·incomplete. | 111 | ····//·operation·is·still·incomplete. |
112 | ····if·(!io_context.stopped()) | 112 | ····if·(!io_context.stopped()) |
113 | ····{ | 113 | ····{ |
114 | ······//·Close·the·socket·to·cancel·the·outstanding·asynchronous·operation. | 114 | ······//·Close·the·socket·to·cancel·the·outstanding·asynchronous·operation. |
115 | ······socket_.close(); | 115 | ······socket_.close(); |
116 | | 116 | |
117 | ······//·Run·the·io_context·again·until·the·operation·completes. | 117 | ······//·Run·the·io_context·again·until·the·operation·completes. |
118 | ······io_context.run(); | 118 | ······io_context.run(); |
119 | ····} | 119 | ····} |
120 | | 120 | |
121 | ····//·If·the·operation·failed,·throw·an·exception.·Otherwise·return·the·result. | 121 | ····//·If·the·operation·failed,·throw·an·exception.·Otherwise·return·the·result. |
122 | ····return·ec_·?·throw·asio::system_error(ec_)·:·t_; | 122 | ····return·error_·?·throw·std::system_error(error_)·:·t_; |
123 | ··} | 123 | ··} |
124 | | 124 | |
125 | private: | 125 | private: |
126 | ··asio::chrono::steady_clock::duration·timeout_; | 126 | ··std::chrono::steady_clock::duration·timeout_; |
127 | ··tcp::socket&·socket_; | 127 | ··tcp::socket&·socket_; |
128 | ··asio::error_code·ec_; | 128 | ··std::error_code·error_; |
129 | ··T·t_; | 129 | ··T·t_; |
130 | }; | 130 | }; |
131 | | 131 | |
132 | }·//·namespace·asio | 132 | }·//·namespace·asio |
133 | | 133 | |
134 | //---------------------------------------------------------------------- | 134 | //---------------------------------------------------------------------- |
135 | | 135 | |
136 | int·main(int·argc,·char*·argv[]) | 136 | int·main(int·argc,·char*·argv[]) |
137 | { | 137 | { |
138 | ··try | 138 | ··try |
139 | ··{ | 139 | ··{ |
140 | ····if·(argc·!=·4) | 140 | ····if·(argc·!=·4) |
141 | ····{ | 141 | ····{ |
142 | ······std::cerr·<<·"Usage:·blocking_tcp_client·<host>·<port>·<message>\n"; | 142 | ······std::cerr·<<·"Usage:·blocking_tcp_client·<host>·<port>·<message>\n"; |
143 | ······return·1; | 143 | ······return·1; |
144 | ····} | 144 | ····} |
145 | | 145 | |
146 | ····asio::io_context·io_context; | 146 | ····asio::io_context·io_context; |
147 | | 147 | |
148 | ····//·Resolve·the·host·name·and·service·to·a·list·of·endpoints. | 148 | ····//·Resolve·the·host·name·and·service·to·a·list·of·endpoints. |
149 | ····tcp::resolver::results_type·endpoints·= | 149 | ····auto·endpoints·=·tcp::resolver(io_context).resolve(argv[1],·argv[2]); |
150 | ······tcp::resolver(io_context).resolve(argv[1],·argv[2]); | |
151 | | 150 | |
152 | ····tcp::socket·socket(io_context); | 151 | ····tcp::socket·socket(io_context); |
153 | | 152 | |
154 | ····//·Run·an·asynchronous·connect·operation·with·a·timeout. | 153 | ····//·Run·an·asynchronous·connect·operation·with·a·timeout. |
155 | ····asio::async_connect(socket,·endpoints, | 154 | ····asio::async_connect(socket,·endpoints, |
156 | ········close_after(asio::chrono::seconds(10),·socket)); | 155 | ········close_after(std::chrono::seconds(10),·socket)); |
157 | | 156 | |
158 | ····asio::chrono::steady_clock::time_point·time_sent·= | 157 | ····auto·time_sent·=·std::chrono::steady_clock::now(); |
159 | ······asio::chrono::steady_clock::now(); | |
160 | | 158 | |
161 | ····//·Run·an·asynchronous·write·operation·with·a·timeout. | 159 | ····//·Run·an·asynchronous·write·operation·with·a·timeout. |
162 | ····std::string·msg·=·argv[3]·+·std::string("\n"); | 160 | ····std::string·msg·=·argv[3]·+·std::string("\n"); |
163 | ····asio::async_write(socket,·asio::buffer(msg), | 161 | ····asio::async_write(socket,·asio::buffer(msg), |
164 | ········close_after(asio::chrono::seconds(10),·socket)); | 162 | ········close_after(std::chrono::seconds(10),·socket)); |
165 | | 163 | |
166 | ····for·(std::string·input_buffer;;) | 164 | ····for·(std::string·input_buffer;;) |
167 | ····{ | 165 | ····{ |
168 | ······//·Run·an·asynchronous·read·operation·with·a·timeout. | 166 | ······//·Run·an·asynchronous·read·operation·with·a·timeout. |
169 | ······std::size_t·n·=·asio::async_read_until(socket, | 167 | ······std::size_t·n·=·asio::async_read_until(socket, |
170 | ··········asio::dynamic_buffer(input_buffer),·'\n', | 168 | ··········asio::dynamic_buffer(input_buffer),·'\n', |
171 | ··········close_after(asio::chrono::seconds(10),·socket)); | 169 | ··········close_after(std::chrono::seconds(10),·socket)); |
172 | | 170 | |
173 | ······std::string·line(input_buffer.substr(0,·n·-·1)); | 171 | ······std::string·line(input_buffer.substr(0,·n·-·1)); |
174 | ······input_buffer.erase(0,·n); | 172 | ······input_buffer.erase(0,·n); |
175 | | 173 | |
176 | ······//·Keep·going·until·we·get·back·the·line·that·was·sent. | 174 | ······//·Keep·going·until·we·get·back·the·line·that·was·sent. |
177 | ······if·(line·==·argv[3]) | 175 | ······if·(line·==·argv[3]) |
178 | ········break; | 176 | ········break; |
179 | ····} | 177 | ····} |
180 | | 178 | |
181 | ····asio::chrono::steady_clock::time_point·time_received·= | 179 | ····auto·time_received·=·std::chrono::steady_clock::now(); |
182 | ······asio::chrono::steady_clock::now(); | |
183 | | 180 | |
184 | ····std::cout·<<·"Round·trip·time:·"; | 181 | ····std::cout·<<·"Round·trip·time:·"; |
185 | ····std::cout·<<·asio::chrono::duration_cast< | 182 | ····std::cout·<<·std::chrono::duration_cast< |
186 | ······asio::chrono::microseconds>( | 183 | ······std::chrono::microseconds>( |
187 | ········time_received·-·time_sent).count(); | 184 | ········time_received·-·time_sent).count(); |
188 | ····std::cout·<<·"·microseconds\n"; | 185 | ····std::cout·<<·"·microseconds\n"; |
189 | ··} | 186 | ··} |
190 | ··catch·(std::exception&·e) | 187 | ··catch·(std::exception&·e) |
191 | ··{ | 188 | ··{ |
192 | ····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n"; | 189 | ····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n"; |
193 | ··} | 190 | ··} |
194 | | 191 | |
195 | ··return·0; | 192 | ··return·0; |
196 | } | 193 | } |