src/examples/cpp03/timeouts/blocking_tcp_client.cpp | src/examples/cpp11/timeouts/blocking_tcp_client.cpp |
⋮ | ⋮ |
1 | // | 1 | // |
2 | //·blocking_tcp_client.cpp | 2 | //·blocking_tcp_client.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·"asio/buffer.hpp" | 11 | #include·"asio/buffer.hpp" |
12 | #include·"asio/connect.hpp" | 12 | #include·"asio/connect.hpp" |
13 | #include·"asio/io_context.hpp" | 13 | #include·"asio/io_context.hpp" |
14 | #include·"asio/ip/tcp.hpp" | 14 | #include·"asio/ip/tcp.hpp" |
15 | #include·"asio/read_until.hpp" | 15 | #include·"asio/read_until.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·<string> | 20 | #include·<string> |
21 | #include·<boost/lambda/bind.hpp> | |
22 | #include·<boost/lambda/lambda.hpp> | |
23 | | 21 | |
24 | using·asio::ip::tcp; | 22 | using·asio::ip::tcp; |
25 | using·boost::lambda::bind; | |
26 | using·boost::lambda::var; | |
27 | using·boost::lambda::_1; | |
28 | using·boost::lambda::_2; | |
29 | | 23 | |
30 | //---------------------------------------------------------------------- | 24 | //---------------------------------------------------------------------- |
31 | | 25 | |
32 | // | 26 | // |
33 | //·This·class·manages·socket·timeouts·by·running·the·io_context·using·the·timed | 27 | //·This·class·manages·socket·timeouts·by·running·the·io_context·using·the·timed |
34 | //·io_context::run_for()·member·function.·Each·asynchronous·operation·is·given | 28 | //·io_context::run_for()·member·function.·Each·asynchronous·operation·is·given |
35 | //·a·timeout·within·which·it·must·complete.·The·socket·operations·themselves | 29 | //·a·timeout·within·which·it·must·complete.·The·socket·operations·themselves |
36 | //·use·boost::lambda·function·objects·as·completion·handlers.·For·a·given | 30 | //·use·lambdas·as·completion·handlers.·For·a·given·socket·operation,·the·client |
37 | //·socket·operation,·the·client·object·runs·the·io_context·to·block·thread | 31 | //·object·runs·the·io_context·to·block·thread·execution·until·the·operation |
38 | //·execution·until·the·operation·completes·or·the·timeout·is·reached.·If·the | 32 | //·completes·or·the·timeout·is·reached.·If·the·io_context::run_for()·function |
39 | //·io_context::run_for()·function·times·out,·the·socket·is·closed·and·the | 33 | //·times·out,·the·socket·is·closed·and·the·outstanding·asynchronous·operation |
40 | //·outstanding·asynchronous·operation·is·cancelled. | 34 | //·is·cancelled. |
41 | // | 35 | // |
42 | class·client | 36 | class·client |
43 | { | 37 | { |
44 | public: | 38 | public: |
45 | ··client() | |
46 | ····:·socket_(io_context_) | |
47 | ··{ | |
48 | ··} | |
49 | | |
50 | ··void·connect(const·std::string&·host,·const·std::string&·service, | 39 | ··void·connect(const·std::string&·host,·const·std::string&·service, |
51 | ······asio::chrono::steady_clock::duration·timeout) | 40 | ······std::chrono::steady_clock::duration·timeout) |
52 | ··{ | 41 | ··{ |
53 | ····//·Resolve·the·host·name·and·service·to·a·list·of·endpoints. | 42 | ····//·Resolve·the·host·name·and·service·to·a·list·of·endpoints. |
54 | ····tcp::resolver::results_type·endpoints·= | 43 | ····auto·endpoints·=·tcp::resolver(io_context_).resolve(host,·service); |
55 | ······tcp::resolver(io_context_).resolve(host,·service); | |
56 | | 44 | |
57 | ····//·Start·the·asynchronous·operation·itself.·The·boost::lambda·function | 45 | ····//·Start·the·asynchronous·operation·itself.·The·lambda·that·is·used·as·a |
58 | ····//·object·is·used·as·a·callback·and·will·update·the·ec·variable·when·the | 46 | ····//·callback·will·update·the·error·variable·when·the·operation·completes. |
59 | ····//·operation·completes.·The·blocking_udp_client.cpp·example·shows·how·you | 47 | ····//·The·blocking_udp_client.cpp·example·shows·how·you·can·use·std::bind |
60 | ····//·can·use·boost::bind·rather·than·boost::lambda. | 48 | ····//·rather·than·a·lambda. |
61 | ····asio::error_code·ec; | 49 | ····std::error_code·error; |
62 | ····asio::async_connect(socket_,·endpoints,·var(ec)·=·_1); | 50 | ····asio::async_connect(socket_,·endpoints, |
| 51 | ········[&](const·std::error_code&·result_error, |
| 52 | ············const·tcp::endpoint&·/*result_endpoint*/) |
| 53 | ········{ |
| 54 | ··········error·=·result_error; |
| 55 | ········}); |
63 | | 56 | |
64 | ····//·Run·the·operation·until·it·completes,·or·until·the·timeout. | 57 | ····//·Run·the·operation·until·it·completes,·or·until·the·timeout. |
65 | ····run(timeout); | 58 | ····run(timeout); |
66 | | 59 | |
67 | ····//·Determine·whether·a·connection·was·successfully·established. | 60 | ····//·Determine·whether·a·connection·was·successfully·established. |
68 | ····if·(ec) | 61 | ····if·(error) |
69 | ······throw·asio::system_error(ec); | 62 | ······throw·std::system_error(error); |
70 | ··} | 63 | ··} |
71 | | 64 | |
72 | ··std::string·read_line(asio::chrono::steady_clock::duration·timeout) | 65 | ··std::string·read_line(std::chrono::steady_clock::duration·timeout) |
73 | ··{ | 66 | ··{ |
74 | ····//·Start·the·asynchronous·operation.·The·boost::lambda·function·object·is | 67 | ····//·Start·the·asynchronous·operation.·The·lambda·that·is·used·as·a·callback |
75 | ····//·used·as·a·callback·and·will·update·the·ec·variable·when·the·operation | 68 | ····//·will·update·the·error·and·n·variables·when·the·operation·completes.·The |
76 | ····//·completes.·The·blocking_udp_client.cpp·example·shows·how·you·can·use | 69 | ····//·blocking_udp_client.cpp·example·shows·how·you·can·use·std::bind·rather |
77 | ····//·boost::bind·rather·than·boost::lambda. | 70 | ····//·than·a·lambda. |
78 | ····asio::error_code·ec; | 71 | ····std::error_code·error; |
79 | ····std::size_t·n·=·0; | 72 | ····std::size_t·n·=·0; |
80 | ····asio::async_read_until(socket_, | 73 | ····asio::async_read_until(socket_, |
81 | ········asio::dynamic_buffer(input_buffer_), | 74 | ········asio::dynamic_buffer(input_buffer_),·'\n', |
82 | ········'\n',·(var(ec)·=·_1,·var(n)·=·_2)); | 75 | ········[&](const·std::error_code&·result_error, |
| 76 | ············std::size_t·result_n) |
| 77 | ········{ |
| 78 | ··········error·=·result_error; |
| 79 | ··········n·=·result_n; |
| 80 | ········}); |
83 | | 81 | |
84 | ····//·Run·the·operation·until·it·completes,·or·until·the·timeout. | 82 | ····//·Run·the·operation·until·it·completes,·or·until·the·timeout. |
85 | ····run(timeout); | 83 | ····run(timeout); |
86 | | 84 | |
87 | ····//·Determine·whether·the·read·completed·successfully. | 85 | ····//·Determine·whether·the·read·completed·successfully. |
88 | ····if·(ec) | 86 | ····if·(error) |
89 | ······throw·asio::system_error(ec); | 87 | ······throw·std::system_error(error); |
90 | | 88 | |
91 | ····std::string·line(input_buffer_.substr(0,·n·-·1)); | 89 | ····std::string·line(input_buffer_.substr(0,·n·-·1)); |
92 | ····input_buffer_.erase(0,·n); | 90 | ····input_buffer_.erase(0,·n); |
93 | ····return·line; | 91 | ····return·line; |
94 | ··} | 92 | ··} |
95 | | 93 | |
96 | ··void·write_line(const·std::string&·line, | 94 | ··void·write_line(const·std::string&·line, |
97 | ······asio::chrono::steady_clock::duration·timeout) | 95 | ······std::chrono::steady_clock::duration·timeout) |
98 | ··{ | 96 | ··{ |
99 | ····std::string·data·=·line·+·"\n"; | 97 | ····std::string·data·=·line·+·"\n"; |
100 | | 98 | |
101 | ····//·Start·the·asynchronous·operation.·The·boost::lambda·function·object·is | 99 | ····//·Start·the·asynchronous·operation·itself.·The·lambda·that·is·used·as·a |
102 | ····//·used·as·a·callback·and·will·update·the·ec·variable·when·the·operation | 100 | ····//·callback·will·update·the·error·variable·when·the·operation·completes. |
103 | ····//·completes.·The·blocking_udp_client.cpp·example·shows·how·you·can·use | 101 | ····//·The·blocking_udp_client.cpp·example·shows·how·you·can·use·std::bind |
104 | ····//·boost::bind·rather·than·boost::lambda. | 102 | ····//·rather·than·a·lambda. |
105 | ····asio::error_code·ec; | 103 | ····std::error_code·error; |
106 | ····asio::async_write(socket_,·asio::buffer(data),·var(ec)·=·_1); | 104 | ····asio::async_write(socket_,·asio::buffer(data), |
| 105 | ········[&](const·std::error_code&·result_error, |
| 106 | ············std::size_t·/*result_n*/) |
| 107 | ········{ |
| 108 | ··········error·=·result_error; |
| 109 | ········}); |
107 | | 110 | |
108 | ····//·Run·the·operation·until·it·completes,·or·until·the·timeout. | 111 | ····//·Run·the·operation·until·it·completes,·or·until·the·timeout. |
109 | ····run(timeout); | 112 | ····run(timeout); |
110 | | 113 | |
111 | ····//·Determine·whether·the·read·completed·successfully. | 114 | ····//·Determine·whether·the·read·completed·successfully. |
112 | ····if·(ec) | 115 | ····if·(error) |
113 | ······throw·asio::system_error(ec); | 116 | ······throw·std::system_error(error); |
114 | ··} | 117 | ··} |
115 | | 118 | |
116 | private: | 119 | private: |
117 | ··void·run(asio::chrono::steady_clock::duration·timeout) | 120 | ··void·run(std::chrono::steady_clock::duration·timeout) |
118 | ··{ | 121 | ··{ |
119 | ····//·Restart·the·io_context,·as·it·may·have·been·left·in·the·"stopped"·state | 122 | ····//·Restart·the·io_context,·as·it·may·have·been·left·in·the·"stopped"·state |
120 | ····//·by·a·previous·operation. | 123 | ····//·by·a·previous·operation. |
121 | ····io_context_.restart(); | 124 | ····io_context_.restart(); |
122 | | 125 | |
123 | ····//·Block·until·the·asynchronous·operation·has·completed,·or·timed·out.·If | 126 | ····//·Block·until·the·asynchronous·operation·has·completed,·or·timed·out.·If |
124 | ····//·the·pending·asynchronous·operation·is·a·composed·operation,·the·deadline | 127 | ····//·the·pending·asynchronous·operation·is·a·composed·operation,·the·deadline |
125 | ····//·applies·to·the·entire·operation,·rather·than·individual·operations·on | 128 | ····//·applies·to·the·entire·operation,·rather·than·individual·operations·on |
126 | ····//·the·socket. | 129 | ····//·the·socket. |
127 | ····io_context_.run_for(timeout); | 130 | ····io_context_.run_for(timeout); |
128 | | 131 | |
129 | ····//·If·the·asynchronous·operation·completed·successfully·then·the·io_context | 132 | ····//·If·the·asynchronous·operation·completed·successfully·then·the·io_context |
130 | ····//·would·have·been·stopped·due·to·running·out·of·work.·If·it·was·not | 133 | ····//·would·have·been·stopped·due·to·running·out·of·work.·If·it·was·not |
131 | ····//·stopped,·then·the·io_context::run_for·call·must·have·timed·out. | 134 | ····//·stopped,·then·the·io_context::run_for·call·must·have·timed·out. |
132 | ····if·(!io_context_.stopped()) | 135 | ····if·(!io_context_.stopped()) |
133 | ····{ | 136 | ····{ |
134 | ······//·Close·the·socket·to·cancel·the·outstanding·asynchronous·operation. | 137 | ······//·Close·the·socket·to·cancel·the·outstanding·asynchronous·operation. |
135 | ······socket_.close(); | 138 | ······socket_.close(); |
136 | | 139 | |
137 | ······//·Run·the·io_context·again·until·the·operation·completes. | 140 | ······//·Run·the·io_context·again·until·the·operation·completes. |
138 | ······io_context_.run(); | 141 | ······io_context_.run(); |
139 | ····} | 142 | ····} |
140 | ··} | 143 | ··} |
141 | | 144 | |
142 | ··asio::io_context·io_context_; | 145 | ··asio::io_context·io_context_; |
143 | ··tcp::socket·socket_; | 146 | ··tcp::socket·socket_{io_context_}; |
144 | ··std::string·input_buffer_; | 147 | ··std::string·input_buffer_; |
145 | }; | 148 | }; |
146 | | 149 | |
147 | //---------------------------------------------------------------------- | 150 | //---------------------------------------------------------------------- |
148 | | 151 | |
149 | int·main(int·argc,·char*·argv[]) | 152 | int·main(int·argc,·char*·argv[]) |
150 | { | 153 | { |
151 | ··try | 154 | ··try |
152 | ··{ | 155 | ··{ |
153 | ····if·(argc·!=·4) | 156 | ····if·(argc·!=·4) |
154 | ····{ | 157 | ····{ |
155 | ······std::cerr·<<·"Usage:·blocking_tcp_client·<host>·<port>·<message>\n"; | 158 | ······std::cerr·<<·"Usage:·blocking_tcp_client·<host>·<port>·<message>\n"; |
156 | ······return·1; | 159 | ······return·1; |
157 | ····} | 160 | ····} |
158 | | 161 | |
159 | ····client·c; | 162 | ····client·c; |
160 | ····c.connect(argv[1],·argv[2],·asio::chrono::seconds(10)); | 163 | ····c.connect(argv[1],·argv[2],·std::chrono::seconds(10)); |
161 | | 164 | |
162 | ····asio::chrono::steady_clock::time_point·time_sent·= | 165 | ····auto·time_sent·=·std::chrono::steady_clock::now(); |
163 | ······asio::chrono::steady_clock::now(); | |
164 | | 166 | |
165 | ····c.write_line(argv[3],·asio::chrono::seconds(10)); | 167 | ····c.write_line(argv[3],·std::chrono::seconds(10)); |
166 | | 168 | |
167 | ····for·(;;) | 169 | ····for·(;;) |
168 | ····{ | 170 | ····{ |
169 | ······std::string·line·=·c.read_line(asio::chrono::seconds(10)); | 171 | ······std::string·line·=·c.read_line(std::chrono::seconds(10)); |
170 | | 172 | |
171 | ······//·Keep·going·until·we·get·back·the·line·that·was·sent. | 173 | ······//·Keep·going·until·we·get·back·the·line·that·was·sent. |
172 | ······if·(line·==·argv[3]) | 174 | ······if·(line·==·argv[3]) |
173 | ········break; | 175 | ········break; |
174 | ····} | 176 | ····} |
175 | | 177 | |
176 | ····asio::chrono::steady_clock::time_point·time_received·= | 178 | ····auto·time_received·=·std::chrono::steady_clock::now(); |
177 | ······asio::chrono::steady_clock::now(); | |
178 | | 179 | |
179 | ····std::cout·<<·"Round·trip·time:·"; | 180 | ····std::cout·<<·"Round·trip·time:·"; |
180 | ····std::cout·<<·asio::chrono::duration_cast< | 181 | ····std::cout·<<·std::chrono::duration_cast< |
181 | ······asio::chrono::microseconds>( | 182 | ······std::chrono::microseconds>( |
182 | ········time_received·-·time_sent).count(); | 183 | ········time_received·-·time_sent).count(); |
183 | ····std::cout·<<·"·microseconds\n"; | 184 | ····std::cout·<<·"·microseconds\n"; |
184 | ··} | 185 | ··} |
185 | ··catch·(std::exception&·e) | 186 | ··catch·(std::exception&·e) |
186 | ··{ | 187 | ··{ |
187 | ····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n"; | 188 | ····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n"; |
188 | ··} | 189 | ··} |
189 | | 190 | |
190 | ··return·0; | 191 | ··return·0; |
191 | } | 192 | } |