| 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)·2003-2022·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/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 | //·NOTE:·This·example·uses·the·new·form·of·the·asio::async_result·trait. |
| | 26 | //·For·an·example·that·works·with·the·Networking·TS·style·of·completion·tokens, |
| | 27 | //·please·see·an·older·version·of·asio. |
| | 28 | |
| 25 | //·We·will·use·our·sockets·only·with·an·io_context. | 29 | //·We·will·use·our·sockets·only·with·an·io_context. |
| 26 | typedef·asio::basic_stream_socket<tcp, | 30 | using·tcp_socket·=·asio::basic_stream_socket< |
| 27 | ····asio::io_context::executor_type>·tcp_socket; | 31 | ····tcp,·asio::io_context::executor_type>; |
| 28 | | 32 | |
| 29 | //---------------------------------------------------------------------- | 33 | //---------------------------------------------------------------------- |
| 30 | | 34 | |
| 31 | //·A·custom·completion·token·that·makes·asynchronous·operations·behave·as | 35 | //·A·custom·completion·token·that·makes·asynchronous·operations·behave·as |
| 32 | //·though·they·are·blocking·calls·with·a·timeout. | 36 | //·though·they·are·blocking·calls·with·a·timeout. |
| 33 | struct·close_after | 37 | struct·close_after |
| 34 | { | 38 | { |
| 35 | ··close_after(asio::chrono::steady_clock::duration·t,·tcp_socket&·s) | 39 | ··close_after(std::chrono::steady_clock::duration·t,·tcp_socket&·s) |
| 36 | ····:·timeout_(t),·socket_(s) | 40 | ····:·timeout_(t),·socket_(s) |
| 37 | ··{ | 41 | ··{ |
| 38 | ··} | 42 | ··} |
| 39 | | 43 | |
| 40 | ··//·The·maximum·time·to·wait·for·an·asynchronous·operation·to·complete. | 44 | ··//·The·maximum·time·to·wait·for·an·asynchronous·operation·to·complete. |
| 41 | ··asio::chrono::steady_clock::duration·timeout_; | 45 | ··std::chrono::steady_clock::duration·timeout_; |
| 42 | | 46 | |
| 43 | ··//·The·socket·to·be·closed·if·the·operation·does·not·complete·in·time. | 47 | ··//·The·socket·to·be·closed·if·the·operation·does·not·complete·in·time. |
| 44 | ··tcp_socket&·socket_; | 48 | ··tcp_socket&·socket_; |
| 45 | }; | 49 | }; |
| 46 | | 50 | |
| 47 | namespace·asio·{ | 51 | namespace·asio·{ |
| 48 | | 52 | |
| 49 | //·The·async_result·template·is·specialised·to·allow·the·close_after·token·to | 53 | //·The·async_result·template·is·specialised·to·allow·the·close_after·token·to |
| 50 | //·be·used·with·asynchronous·operations·that·have·a·completion·signature·of | 54 | //·be·used·with·asynchronous·operations·that·have·a·completion·signature·of |
| 51 | //·void(error_code,·T).·Generalising·this·for·all·completion·signature·forms·is | 55 | //·void(error_code,·T).·Generalising·this·for·all·completion·signature·forms·is |
| 52 | //·left·as·an·exercise·for·the·reader. | 56 | //·left·as·an·exercise·for·the·reader. |
| 53 | template·<typename·T> | 57 | template·<typename·T> |
| 54 | class·async_result<close_after,·void(asio::error_code,·T)> | 58 | class·async_result<close_after,·void(std::error_code,·T)> |
| 55 | { | 59 | { |
| 56 | public: | 60 | public: |
| 57 | ··//·An·asynchronous·operation's·initiating·function·automatically·creates·an | 61 | ··//·The·initiate()·function·is·used·to·launch·the·asynchronous·operation·by |
| 58 | ··//·completion_handler_type·object·from·the·token.·This·function·object·is | 62 | ··//·calling·the·operation's·initiation·function·object.·For·the·close_after |
| 59 | ··//·then·called·on·completion·of·the·asynchronous·operation. | 63 | ··//·completion·token,·we·use·this·function·to·run·the·io_context·until·the |
| 60 | ··class·completion_handler_type | 64 | ··//·operation·is·complete. |
| | 65 | ··template·<typename·Init,·typename...·Args> |
| | 66 | ··static·T·initiate(Init·init,·close_after·token,·Args&&...·args) |
| 61 | ··{ | 67 | ··{ |
| 62 | ··public: | |
| 63 | ····completion_handler_type(const·close_after&·token) | |
| 64 | ······:·token_(token) | |
| 65 | ····{ | |
| 66 | ····} | |
| 67 | | |
| 68 | ····void·operator()(asio::error_code·ec,·T·t) | |
| 69 | ····{ | |
| 70 | ······*ec_·=·ec; | |
| 71 | ······*t_·=·t; | |
| 72 | ····} | |
| 73 | | |
| 74 | ··private: | |
| 75 | ····friend·class·async_result; | |
| 76 | ····close_after·token_; | |
| 77 | ····asio::error_code*·ec_; | |
| 78 | ····T*·t_; | |
| 79 | ··}; | |
| 80 | | |
| 81 | ··//·The·async_result·constructor·associates·the·completion·handler·object·with | |
| 82 | ··//·the·result·of·the·initiating·function. | |
| 83 | ··explicit·async_result(completion_handler_type&·h) | |
| 84 | ····:·timeout_(h.token_.timeout_), | |
| 85 | ······socket_(h.token_.socket_) | |
| 86 | ··{ | |
| 87 | ····h.ec_·=·&ec_; | |
| 88 | ····h.t_·=·&t_; | |
| 89 | ··} | |
| 90 | | |
| 91 | ··//·The·return_type·typedef·determines·the·result·type·of·the·asynchronous | |
| 92 | ··//·operation's·initiating·function. | |
| 93 | ··typedef·T·return_type; | |
| 94 | | |
| 95 | ··//·The·get()·function·is·used·to·obtain·the·result·of·the·asynchronous | |
| 96 | ··//·operation's·initiating·function.·For·the·close_after·completion·token,·we | |
| 97 | ··//·use·this·function·to·run·the·io_context·until·the·operation·is·complete. | |
| 98 | ··return_type·get() | |
| 99 | ··{ | |
| 100 | ····asio::io_context&·io_context·=·asio::query( | 68 | ····asio::io_context&·io_context·=·asio::query( |
| 101 | ········socket_.get_executor(),·asio::execution::context); | 69 | ········token.socket_.get_executor(),·asio::execution::context); |
| 102 | | 70 | |
| | 71 | ····//·Call·the·operation's·initiation·function·object·to·start·the·operation. |
| | 72 | ····//·A·lambda·is·supplied·as·the·completion·handler,·to·be·called·when·the |
| | 73 | ····//·operation·completes. |
| | 74 | ····std::error_code·error; |
| | 75 | ····T·result; |
| | 76 | ····init([&](std::error_code·e,·T·t) |
| | 77 | ········{ |
| | 78 | ··········error·=·e; |
| | 79 | ··········result·=·t; |
| | 80 | ········},·std::forward<Args>(args)...); |
| | 81 | |
| 103 | ····//·Restart·the·io_context,·as·it·may·have·been·left·in·the·"stopped"·state | 82 | ····//·Restart·the·io_context,·as·it·may·have·been·left·in·the·"stopped"·state |
| 104 | ····//·by·a·previous·operation. | 83 | ····//·by·a·previous·operation. |
| 105 | ····io_context.restart(); | 84 | ····io_context.restart(); |
| 106 | | 85 | |
| 107 | ····//·Block·until·the·asynchronous·operation·has·completed,·or·timed·out.·If | 86 | ····//·Block·until·the·asynchronous·operation·has·completed,·or·timed·out.·If |
| 108 | ····//·the·pending·asynchronous·operation·is·a·composed·operation,·the·deadline | 87 | ····//·the·pending·asynchronous·operation·is·a·composed·operation,·the·deadline |
| 109 | ····//·applies·to·the·entire·operation,·rather·than·individual·operations·on | 88 | ····//·applies·to·the·entire·operation,·rather·than·individual·operations·on |
| 110 | ····//·the·socket. | 89 | ····//·the·socket. |
| 111 | ····io_context.run_for(timeout_); | 90 | ····io_context.run_for(token.timeout_); |
| 112 | | 91 | |
| 113 | ····//·If·the·asynchronous·operation·completed·successfully·then·the·io_context | 92 | ····//·If·the·asynchronous·operation·completed·successfully·then·the·io_context |
| 114 | ····//·would·have·been·stopped·due·to·running·out·of·work.·If·it·was·not | 93 | ····//·would·have·been·stopped·due·to·running·out·of·work.·If·it·was·not |
| 115 | ····//·stopped,·then·the·io_context::run_for·call·must·have·timed·out·and·the | 94 | ····//·stopped,·then·the·io_context::run_for·call·must·have·timed·out·and·the |
| 116 | ····//·operation·is·still·incomplete. | 95 | ····//·operation·is·still·incomplete. |
| 117 | ····if·(!io_context.stopped()) | 96 | ····if·(!io_context.stopped()) |
| 118 | ····{ | 97 | ····{ |
| 119 | ······//·Close·the·socket·to·cancel·the·outstanding·asynchronous·operation. | 98 | ······//·Close·the·socket·to·cancel·the·outstanding·asynchronous·operation. |
| 120 | ······socket_.close(); | 99 | ······token.socket_.close(); |
| 121 | | 100 | |
| 122 | ······//·Run·the·io_context·again·until·the·operation·completes. | 101 | ······//·Run·the·io_context·again·until·the·operation·completes. |
| 123 | ······io_context.run(); | 102 | ······io_context.run(); |
| 124 | ····} | 103 | ····} |
| 125 | | 104 | |
| 126 | ····//·If·the·operation·failed,·throw·an·exception.·Otherwise·return·the·result. | 105 | ····//·If·the·operation·failed,·throw·an·exception.·Otherwise·return·the·result. |
| 127 | ····return·ec_·?·throw·asio::system_error(ec_)·:·t_; | 106 | ····return·error·?·throw·std::system_error(error)·:·result; |
| 128 | ··} | 107 | ··} |
| 129 | | |
| 130 | private: | |
| 131 | ··asio::chrono::steady_clock::duration·timeout_; | |
| 132 | ··tcp_socket&·socket_; | |
| 133 | ··asio::error_code·ec_; | |
| 134 | ··T·t_; | |
| 135 | }; | 108 | }; |
| 136 | | 109 | |
| 137 | }·//·namespace·asio | 110 | }·//·namespace·asio |
| 138 | | 111 | |
| 139 | //---------------------------------------------------------------------- | 112 | //---------------------------------------------------------------------- |
| 140 | | 113 | |
| 141 | int·main(int·argc,·char*·argv[]) | 114 | int·main(int·argc,·char*·argv[]) |
| 142 | { | 115 | { |
| 143 | ··try | 116 | ··try |
| 144 | ··{ | 117 | ··{ |
| 145 | ····if·(argc·!=·4) | 118 | ····if·(argc·!=·4) |
| 146 | ····{ | 119 | ····{ |
| 147 | ······std::cerr·<<·"Usage:·blocking_tcp_client·<host>·<port>·<message>\n"; | 120 | ······std::cerr·<<·"Usage:·blocking_tcp_client·<host>·<port>·<message>\n"; |
| 148 | ······return·1; | 121 | ······return·1; |
| 149 | ····} | 122 | ····} |
| 150 | | 123 | |
| 151 | ····asio::io_context·io_context; | 124 | ····asio::io_context·io_context; |
| 152 | | 125 | |
| 153 | ····//·Resolve·the·host·name·and·service·to·a·list·of·endpoints. | 126 | ····//·Resolve·the·host·name·and·service·to·a·list·of·endpoints. |
| 154 | ····tcp::resolver::results_type·endpoints·= | 127 | ····auto·endpoints·=·tcp::resolver(io_context).resolve(argv[1],·argv[2]); |
| 155 | ······tcp::resolver(io_context).resolve(argv[1],·argv[2]); | |
| 156 | | 128 | |
| 157 | ····tcp_socket·socket(io_context); | 129 | ····tcp_socket·socket(io_context); |
| 158 | | 130 | |
| 159 | ····//·Run·an·asynchronous·connect·operation·with·a·timeout. | 131 | ····//·Run·an·asynchronous·connect·operation·with·a·timeout. |
| 160 | ····asio::async_connect(socket,·endpoints, | 132 | ····asio::async_connect(socket,·endpoints, |
| 161 | ········close_after(asio::chrono::seconds(10),·socket)); | 133 | ········close_after(std::chrono::seconds(10),·socket)); |
| 162 | | 134 | |
| 163 | ····asio::chrono::steady_clock::time_point·time_sent·= | 135 | ····auto·time_sent·=·std::chrono::steady_clock::now(); |
| 164 | ······asio::chrono::steady_clock::now(); | |
| 165 | | 136 | |
| 166 | ····//·Run·an·asynchronous·write·operation·with·a·timeout. | 137 | ····//·Run·an·asynchronous·write·operation·with·a·timeout. |
| 167 | ····std::string·msg·=·argv[3]·+·std::string("\n"); | 138 | ····std::string·msg·=·argv[3]·+·std::string("\n"); |
| 168 | ····asio::async_write(socket,·asio::buffer(msg), | 139 | ····asio::async_write(socket,·asio::buffer(msg), |
| 169 | ········close_after(asio::chrono::seconds(10),·socket)); | 140 | ········close_after(std::chrono::seconds(10),·socket)); |
| 170 | | 141 | |
| 171 | ····for·(std::string·input_buffer;;) | 142 | ····for·(std::string·input_buffer;;) |
| 172 | ····{ | 143 | ····{ |
| 173 | ······//·Run·an·asynchronous·read·operation·with·a·timeout. | 144 | ······//·Run·an·asynchronous·read·operation·with·a·timeout. |
| 174 | ······std::size_t·n·=·asio::async_read_until(socket, | 145 | ······std::size_t·n·=·asio::async_read_until(socket, |
| 175 | ··········asio::dynamic_buffer(input_buffer),·'\n', | 146 | ··········asio::dynamic_buffer(input_buffer),·'\n', |
| 176 | ··········close_after(asio::chrono::seconds(10),·socket)); | 147 | ··········close_after(std::chrono::seconds(10),·socket)); |
| 177 | | 148 | |
| 178 | ······std::string·line(input_buffer.substr(0,·n·-·1)); | 149 | ······std::string·line(input_buffer.substr(0,·n·-·1)); |
| 179 | ······input_buffer.erase(0,·n); | 150 | ······input_buffer.erase(0,·n); |
| 180 | | 151 | |
| 181 | ······//·Keep·going·until·we·get·back·the·line·that·was·sent. | 152 | ······//·Keep·going·until·we·get·back·the·line·that·was·sent. |
| 182 | ······if·(line·==·argv[3]) | 153 | ······if·(line·==·argv[3]) |
| 183 | ········break; | 154 | ········break; |
| 184 | ····} | 155 | ····} |
| 185 | | 156 | |
| 186 | ····asio::chrono::steady_clock::time_point·time_received·= | 157 | ····auto·time_received·=·std::chrono::steady_clock::now(); |
| 187 | ······asio::chrono::steady_clock::now(); | |
| 188 | | 158 | |
| 189 | ····std::cout·<<·"Round·trip·time:·"; | 159 | ····std::cout·<<·"Round·trip·time:·"; |
| 190 | ····std::cout·<<·asio::chrono::duration_cast< | 160 | ····std::cout·<<·std::chrono::duration_cast< |
| 191 | ······asio::chrono::microseconds>( | 161 | ······std::chrono::microseconds>( |
| 192 | ········time_received·-·time_sent).count(); | 162 | ········time_received·-·time_sent).count(); |
| 193 | ····std::cout·<<·"·microseconds\n"; | 163 | ····std::cout·<<·"·microseconds\n"; |
| 194 | ··} | 164 | ··} |
| 195 | ··catch·(std::exception&·e) | 165 | ··catch·(std::exception&·e) |
| 196 | ··{ | 166 | ··{ |
| 197 | ····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n"; | 167 | ····std::cerr·<<·"Exception:·"·<<·e.what()·<<·"\n"; |
| 198 | ··} | 168 | ··} |
| 199 | | 169 | |
| 200 | ··return·0; | 170 | ··return·0; |
| 201 | } | 171 | } |