2. Boost Beast Translation (zh_Hans)
3. Doc / Qbk / 03 Core / 3 Timeouts (qbk)
4. English
5. Zen

2 string ID 12
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Network programs must handle adverse connection conditions; the most common is that a connected peer goes offline unexpectedly. Protocols have no way of identifying this reliably: the peer is offline after all, and unable to send a message announcing the absence. A peer can go offline for various reasons: 306/10000 · 306
3 string ID 24
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — To determine when a peer is offline or idle, a program will implement a [@https://en.wikipedia.org/wiki/Timeout_(computing) timeout] algorithm, which closes the connection after a specified amount of time if some condition is met. For example, if no data is received for the duration. A timeout may be used to: 310/10000 · 310
4 string ID 36
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Traditionally, programs use a [@boost:/doc/html/boost_asio/reference/steady_timer.html `net::steady_timer`] to determine when a timeout occurs, and then call [@boost:/doc/html/boost_asio/reference/basic_socket/close/overload2.html `close`] on the socket to release the resources. The complexity of managing a separate timer is often a source of [@http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1269r0.html#timers frustration] for non-experts. 452/10000 · 452
5 string ID 46
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — For portability reasons, networking does not provide timeouts 61/10000 · 61
6 string ID 50
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — To simplify the handling of timeouts, these provided types wrap a [@boost:/doc/html/boost_asio/reference/basic_stream_socket.html `net::basic_stream_socket`] to provide additional features: 189/10000 · 189
7 string ID 54
	Source string description type: table cell
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — [link beast.ref.boost__beast__tcp_stream `tcp_stream`] 54/10000 · 54
8 string ID 54
	Source string description type: table cell
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — [itemized_list [Timeouts for logical operations] [[@boost:/doc/html/boost_asio/reference/ip__tcp.html `net::ip::tcp`] protocol] [[@boost:/doc/html/boost_asio/reference/executor.html `net::executor`] executor] [[link beast.ref.boost__beast__unlimited_rate_policy `unlimited_rate_policy`] rate limits] ] 301/10000 · 301
9 string ID 54
	Source string description type: table cell
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — [link beast.ref.boost__beast__basic_stream `basic_stream`] 58/10000 · 58
10 string ID 54
	Source string description type: table cell
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — [itemized_list [Timeouts for logical operations] [Configurable __Protocol__ type] [Configurable __Executor__ type] [Configurable __RatePolicy__ type] ] 151/10000 · 151
11 string ID 76
	Source string description type: heading
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Construction 12/10000 · 12
12 string ID 78
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The `tcp_stream` is designed as a replacement for [@boost:/doc/html/boost_asio/reference/ip__tcp/socket.html `net::ip::tcp::socket`]. Any program which currently uses a socket, can switch to a `tcp_stream` and achieve the features above (although some interfaces are different, see below). Networking now allows I/O objects to construct with any instance of __ExecutionContext__ or __Executor__ objects. Here we construct a stream which uses a particular I/O context to dispatch completion handlers: 499/10000 · 499
13 string ID 88
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Alternatively, we can construct the stream from an executor: 60/10000 · 60
14 string ID 92
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The function [@boost:/doc/html/boost_asio/reference/make_strand.html `make_strand`] returns a strand constructed from an execution context or executor. When a [@boost:/doc/html/boost_asio/reference/strand.html `net::strand`] is chosen for the stream's executor, all completion handlers which do not already have an associated executor will use the strand. This is both a notational convenience (no need for `strand::wrap` or `bind_executor` at call sites) and a measure of safety, as it is no longer possible to forget to use the strand. 537/10000 · 537
15 string ID 106
	Source string description type: heading
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Connecting 10/10000 · 10
16 string ID 108
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Before data can be exchanged, the stream needs to be connected to a peer. The following code sets a timeout for an asynchronous connect operation. In Beast, functions to connect to a range of endpoints (such as the range returned by [@boost:/doc/html/boost_asio/reference/ip__basic_resolver/resolve/overload3.html `net::ip::tcp::resolver::resolve`]) are members of the class rather than free functions such as [@boost:/doc/html/boost_asio/reference/async_connect.html `net::async_connect`]. 490/10000 · 490
17 string ID 118
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — A server will use an acceptor bound to a particular IP address and port to listen to and receive incoming connection requests. The acceptor returns an ordinary socket. A `tcp_stream` can be move-constructed from the underlying `basic_stream_socket` thusly: 256/10000 · 256
18 string ID 127
	Source string description type: heading
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Reading and Writing 19/10000 · 19
19 string ID 129
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Timeouts apply to the logical operation, expressed as a series of asynchronous calls, rather than just the next call. This code reads a line from the stream and writes it back. Both the read and the write must complete within 30 seconds from when the timeout was set; the timer is not reset between operations. 310/10000 · 310
20 string ID 136
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Since reads and writes can take place concurrently, it is possible to have two simultaneous logical operations where each operation either only reads, or only writes. The beginning of a new read or write operation will use the most recently set timeout. This will not affect operations that are already outstanding. 315/10000 · 315
21 string ID 144
	Source string description type: paragraph
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — When a timeout is set, it cancels any previous read or write timeout for which no outstanding operation is in progress. Algorithms which loop over logical operations simply need to set the timeout once before the logical operation, it is not necessary to call `expires_never` in this case. Here we implement an algorithm which continuously echoes lines back, with a timeout. This example is implemented as a complete function. 426/10000 · 426