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<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Requires a `Future` to complete before the specified duration has elapsed."><title>timeout in actix_web::rt::time - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../../../static.files/rustdoc-dd39b87e5fcfba68.css"><meta name="rustdoc-vars" data-root-path="../../../" data-static-root-path="../../../static.files/" data-current-crate="actix_web" data-themes="" data-resource-suffix="" data-rustdoc-version="1.80.0-nightly (bdbbb6c6a 2024-05-26)" data-channel="nightly" data-search-js="search-d52510db62a78183.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../../../static.files/storage-118b08c4c78b968e.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../../static.files/main-20a3ad099b048cf2.js"></script><noscript><link rel="stylesheet" href="../../../static.files/noscript-df360f571f6edeae.css"></noscript><link rel="icon" href="https://actix.rs/favicon.ico"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button><a class="logo-container" href="../../../actix_web/index.html"><img src="https://actix.rs/img/logo.png" alt=""></a></nav><nav class="sidebar"><div class="sidebar-crate"><a class="logo-container" href="../../../actix_web/index.html"><img src="https://actix.rs/img/logo.png" alt="logo"></a><h2><a href="../../../actix_web/index.html">actix_web</a><span class="version">4.6.0</span></h2></div><div class="sidebar-elems"><h2><a href="index.html">In actix_web::rt::time</a></h2></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Function <a href="../../index.html">actix_web</a>::<wbr><a href="../index.html">rt</a>::<wbr><a href="index.html">time</a>::<wbr><a class="fn" href="#">timeout</a><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><span class="out-of-band"><button id="toggle-all-docs" title="collapse all docs">[<span>−</span>]</button></span></div><pre class="rust item-decl"><code>pub fn timeout<F>(duration: <a class="struct" href="https://doc.rust-lang.org/nightly/core/time/struct.Duration.html" title="struct core::time::Duration">Duration</a>, future: F) -> <a class="struct" href="struct.Timeout.html" title="struct actix_web::rt::time::Timeout">Timeout</a><F> <a href="#" class="tooltip" data-notable-ty="Timeout<F>">ⓘ</a><div class="where">where
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F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html" title="trait core::future::future::Future">Future</a>,</div></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Requires a <code>Future</code> to complete before the specified duration has elapsed.</p>
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<p>If the future completes before the duration has elapsed, then the completed
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value is returned. Otherwise, an error is returned and the future is
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canceled.</p>
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<p>Note that the timeout is checked before polling the future, so if the future
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does not yield during execution then it is possible for the future to complete
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and exceed the timeout <em>without</em> returning an error.</p>
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<p>This function returns a future whose return type is <a href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result"><code>Result</code></a><code><T,</code><a href="crate::time::error::Elapsed"><code>Elapsed</code></a><code>></code>, where <code>T</code> is the
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return type of the provided future.</p>
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<p>If the provided future completes immediately, then the future returned from
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this function is guaranteed to complete immediately with an <a href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html#variant.Ok" title="variant core::result::Result::Ok"><code>Ok</code></a> variant
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no matter the provided duration.</p>
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<h2 id="cancellation"><a class="doc-anchor" href="#cancellation">§</a>Cancellation</h2>
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<p>Cancelling a timeout is done by dropping the future. No additional cleanup
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or other work is required.</p>
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<p>The original future may be obtained by calling <a href="struct.Timeout.html#method.into_inner" title="method actix_web::rt::time::Timeout::into_inner"><code>Timeout::into_inner</code></a>. This
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consumes the <code>Timeout</code>.</p>
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<h2 id="examples"><a class="doc-anchor" href="#examples">§</a>Examples</h2>
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<p>Create a new <code>Timeout</code> set to expire in 10 milliseconds.</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::time::timeout;
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<span class="kw">use </span>tokio::sync::oneshot;
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<span class="kw">use </span>std::time::Duration;
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<span class="kw">let </span>(tx, rx) = oneshot::channel();
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<span class="comment">// Wrap the future with a `Timeout` set to expire in 10 milliseconds.
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</span><span class="kw">if let </span><span class="prelude-val">Err</span>(<span class="kw">_</span>) = timeout(Duration::from_millis(<span class="number">10</span>), rx).<span class="kw">await </span>{
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<span class="macro">println!</span>(<span class="string">"did not receive value within 10 ms"</span>);
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}</code></pre></div>
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<h2 id="panics"><a class="doc-anchor" href="#panics">§</a>Panics</h2>
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<p>This function panics if there is no current timer set.</p>
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<p>It can be triggered when <a href="crate::runtime::Builder::enable_time"><code>Builder::enable_time</code></a> or
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<a href="crate::runtime::Builder::enable_all"><code>Builder::enable_all</code></a> are not included in the builder.</p>
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<p>It can also panic whenever a timer is created outside of a
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Tokio runtime. That is why <code>rt.block_on(sleep(...))</code> will panic,
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since the function is executed outside of the runtime.
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Whereas <code>rt.block_on(async {sleep(...).await})</code> doesn’t panic.
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And this is because wrapping the function on an async makes it lazy,
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and so gets executed inside the runtime successfully without
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panicking.</p>
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</div></details><script type="text/json" id="notable-traits-data">{"Timeout<F>":"<h3>Notable traits for <code><a class=\"struct\" href=\"struct.Timeout.html\" title=\"struct actix_web::rt::time::Timeout\">Timeout</a><T></code></h3><pre><code><div class=\"where\">impl<T> <a class=\"trait\" href=\"https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html\" title=\"trait core::future::future::Future\">Future</a> for <a class=\"struct\" href=\"struct.Timeout.html\" title=\"struct actix_web::rt::time::Timeout\">Timeout</a><T><div class=\"where\">where\n T: <a class=\"trait\" href=\"https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html\" title=\"trait core::future::future::Future\">Future</a>,</div></div><div class=\"where\"> type <a href=\"https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html#associatedtype.Output\" class=\"associatedtype\">Output</a> = <a class=\"enum\" href=\"https://doc.rust-lang.org/nightly/core/result/enum.Result.html\" title=\"enum core::result::Result\">Result</a><<T as <a class=\"trait\" href=\"https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html\" title=\"trait core::future::future::Future\">Future</a>>::<a class=\"associatedtype\" href=\"https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html#associatedtype.Output\" title=\"type core::future::future::Future::Output\">Output</a>, Elapsed>;</div>"}</script></section></div></main></body></html> |