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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="Notifies a single task to wake up."><title>Notify in tokio::sync - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-ca0dd0c4.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="tokio" data-themes="" data-resource-suffix="" data-rustdoc-version="1.93.1 (01f6ddf75 2026-02-11) (Arch Linux rust 1:1.93.1-1)" data-channel="1.93.1" data-search-js="search-9e2438ea.js" data-stringdex-js="stringdex-a3946164.js" data-settings-js="settings-c38705f0.js" ><script src="../../static.files/storage-e2aeef58.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../static.files/main-a410ff4d.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-263c88ec.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc struct"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">Notify</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../tokio/index.html">tokio</a><span class="version">1.49.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Notify</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#examples" title="Examples">Examples</a></li></ul><h3><a href="#implementations">Methods</a></h3><ul class="block method"><li><a href="#method.const_new" title="const_new">const_new</a></li><li><a href="#method.new" title="new">new</a></li><li><a href="#method.notified" title="notified">notified</a></li><li><a href="#method.notified_owned" title="notified_owned">notified_owned</a></li><li><a href="#method.notify_last" title="notify_last">notify_last</a></li><li><a href="#method.notify_one" title="notify_one">notify_one</a></li><li><a href="#method.notify_waiters" title="notify_waiters">notify_waiters</a></li></ul><h3><a href="#trait-implementations">Trait Implementations</a></h3><ul class="block trait-implementation"><li><a href="#impl-Debug-for-Notify" title="Debug">Debug</a></li><li><a href="#impl-Default-for-Notify" title="Default">Default</a></li><li><a href="#impl-RefUnwindSafe-for-Notify" title="RefUnwindSafe">RefUnwindSafe</a></li><li><a href="#impl-UnwindSafe-for-Notify" title="UnwindSafe">UnwindSafe</a></li></ul><h3><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><ul class="block synthetic-implementation"><li><a href="#impl-Freeze-for-Notify" title="!Freeze">!Freeze</a></li><li><a href="#impl-Send-for-Notify" title="Send">Send</a></li><li><a href="#impl-Sync-for-Notify" title="Sync">Sync</a></li><li><a href="#impl-Unpin-for-Notify" title="Unpin">Unpin</a></li></ul><h3><a href="#blanket-implementations">Blanket Implementations</a></h3><ul class="block blanket-implementation"><li><a href="#impl-Any-for-T" title="Any">Any</a></li><li><a href="#impl-Borrow%3CT%3E-for-T" title="Borrow<T>">Borrow<T></a></li><li><a href="#impl-BorrowMut%3CT%3E-for-T" title="BorrowMut<T>">BorrowMut<T></a></li><li><a href="#impl-From%3CT%3E-for-T" title="From<T>">From<T></a></li><li><a href="#impl-Into%3CU%3E-for-T" title="Into<U>">Into<U></a></li><li><a href="#impl-TryFrom%3CU%3E-for-T" title="TryFrom<U>">TryFrom<U></a></li><li><a href="#impl-TryInto%3CU%3E-for-T" title="TryInto<U>">TryInto<U></a></li></ul></section><div id="rustdoc-modnav"><h2><a href="index.html">In tokio::<wbr>sync</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="../index.html">tokio</a>::<wbr><a href="index.html">sync</a></div><h1>Struct <span class="struct">Notify</span> <button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../../src/tokio/sync/notify.rs.html#202-215">Source</a> </span></div><pre class="rust item-decl"><code>pub struct Notify { <span class="comment">/* private fields */</span> }</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Notifies a single task to wake up.</p>
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<p><code>Notify</code> provides a basic mechanism to notify a single task of an event.
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<code>Notify</code> itself does not carry any data. Instead, it is to be used to signal
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another task to perform an operation.</p>
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<p>A <code>Notify</code> can be thought of as a <a href="struct.Semaphore.html" title="struct tokio::sync::Semaphore"><code>Semaphore</code></a> starting with 0 permits. The
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<a href="struct.Notify.html#method.notified" title="method tokio::sync::Notify::notified"><code>notified().await</code></a> method waits for a permit to become available, and
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<a href="struct.Notify.html#method.notify_one" title="method tokio::sync::Notify::notify_one"><code>notify_one()</code></a> sets a permit <strong>if there currently are no available
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permits</strong>.</p>
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<p>The synchronization details of <code>Notify</code> are similar to
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<a href="https://doc.rust-lang.org/1.93.1/std/thread/functions/fn.park.html" title="fn std::thread::functions::park"><code>thread::park</code></a> and <a href="https://doc.rust-lang.org/1.93.1/std/thread/thread/struct.Thread.html#method.unpark" title="method std::thread::thread::Thread::unpark"><code>Thread::unpark</code></a> from std. A <a href="struct.Notify.html" title="struct tokio::sync::Notify"><code>Notify</code></a>
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value contains a single permit. <a href="struct.Notify.html#method.notified" title="method tokio::sync::Notify::notified"><code>notified().await</code></a> waits for the permit to
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be made available, consumes the permit, and resumes. <a href="struct.Notify.html#method.notify_one" title="method tokio::sync::Notify::notify_one"><code>notify_one()</code></a> sets
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the permit, waking a pending task if there is one.</p>
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<p>If <code>notify_one()</code> is called <strong>before</strong> <code>notified().await</code>, then the next
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call to <code>notified().await</code> will complete immediately, consuming the permit.
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Any subsequent calls to <code>notified().await</code> will wait for a new permit.</p>
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<p>If <code>notify_one()</code> is called <strong>multiple</strong> times before <code>notified().await</code>,
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only a <strong>single</strong> permit is stored. The next call to <code>notified().await</code> will
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complete immediately, but the one after will wait for a new permit.</p>
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<h2 id="examples"><a class="doc-anchor" href="#examples">§</a>Examples</h2>
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<p>Basic usage.</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
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<span class="kw">use </span>std::sync::Arc;
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<span class="kw">let </span>notify = Arc::new(Notify::new());
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<span class="kw">let </span>notify2 = notify.clone();
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<span class="kw">let </span>handle = tokio::spawn(<span class="kw">async move </span>{
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notify2.notified().<span class="kw">await</span>;
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<span class="macro">println!</span>(<span class="string">"received notification"</span>);
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});
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<span class="macro">println!</span>(<span class="string">"sending notification"</span>);
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notify.notify_one();
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<span class="comment">// Wait for task to receive notification.
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</span>handle.<span class="kw">await</span>.unwrap();</code></pre></div>
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<p>Unbound multi-producer single-consumer (mpsc) channel.</p>
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<p>No wakeups can be lost when using this channel because the call to
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<code>notify_one()</code> will store a permit in the <code>Notify</code>, which the following call
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to <code>notified()</code> will consume.</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
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<span class="kw">use </span>std::collections::VecDeque;
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<span class="kw">use </span>std::sync::Mutex;
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<span class="kw">struct </span>Channel<T> {
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values: Mutex<VecDeque<T>>,
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notify: Notify,
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}
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<span class="kw">impl</span><T> Channel<T> {
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<span class="kw">pub fn </span>send(<span class="kw-2">&</span><span class="self">self</span>, value: T) {
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<span class="self">self</span>.values.lock().unwrap()
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.push_back(value);
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<span class="comment">// Notify the consumer a value is available
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</span><span class="self">self</span>.notify.notify_one();
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}
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<span class="comment">// This is a single-consumer channel, so several concurrent calls to
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// `recv` are not allowed.
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</span><span class="kw">pub async fn </span>recv(<span class="kw-2">&</span><span class="self">self</span>) -> T {
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<span class="kw">loop </span>{
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<span class="comment">// Drain values
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</span><span class="kw">if let </span><span class="prelude-val">Some</span>(value) = <span class="self">self</span>.values.lock().unwrap().pop_front() {
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<span class="kw">return </span>value;
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}
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<span class="comment">// Wait for values to be available
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</span><span class="self">self</span>.notify.notified().<span class="kw">await</span>;
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}
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}
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}</code></pre></div>
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<p>Unbound multi-producer multi-consumer (mpmc) channel.</p>
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<p>The call to <a href="futures/struct.Notified.html#method.enable" title="method tokio::sync::futures::Notified::enable"><code>enable</code></a> is important because otherwise if you have two
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calls to <code>recv</code> and two calls to <code>send</code> in parallel, the following could
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happen:</p>
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<ol>
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<li>Both calls to <code>try_recv</code> return <code>None</code>.</li>
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<li>Both new elements are added to the vector.</li>
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<li>The <code>notify_one</code> method is called twice, adding only a single
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permit to the <code>Notify</code>.</li>
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<li>Both calls to <code>recv</code> reach the <code>Notified</code> future. One of them
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consumes the permit, and the other sleeps forever.</li>
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</ol>
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<p>By adding the <code>Notified</code> futures to the list by calling <code>enable</code> before
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<code>try_recv</code>, the <code>notify_one</code> calls in step three would remove the
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futures from the list and mark them notified instead of adding a permit
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to the <code>Notify</code>. This ensures that both futures are woken.</p>
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<p>Notice that this failure can only happen if there are two concurrent calls
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to <code>recv</code>. This is why the mpsc example above does not require a call to
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<code>enable</code>.</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
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<span class="kw">use </span>std::collections::VecDeque;
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<span class="kw">use </span>std::sync::Mutex;
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<span class="kw">struct </span>Channel<T> {
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messages: Mutex<VecDeque<T>>,
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notify_on_sent: Notify,
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}
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<span class="kw">impl</span><T> Channel<T> {
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<span class="kw">pub fn </span>send(<span class="kw-2">&</span><span class="self">self</span>, msg: T) {
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<span class="kw">let </span><span class="kw-2">mut </span>locked_queue = <span class="self">self</span>.messages.lock().unwrap();
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locked_queue.push_back(msg);
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drop(locked_queue);
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<span class="comment">// Send a notification to one of the calls currently
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// waiting in a call to `recv`.
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</span><span class="self">self</span>.notify_on_sent.notify_one();
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}
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<span class="kw">pub fn </span>try_recv(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><T> {
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<span class="kw">let </span><span class="kw-2">mut </span>locked_queue = <span class="self">self</span>.messages.lock().unwrap();
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locked_queue.pop_front()
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}
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<span class="kw">pub async fn </span>recv(<span class="kw-2">&</span><span class="self">self</span>) -> T {
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<span class="kw">let </span>future = <span class="self">self</span>.notify_on_sent.notified();
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<span class="macro">tokio::pin!</span>(future);
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<span class="kw">loop </span>{
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<span class="comment">// Make sure that no wakeup is lost if we get
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// `None` from `try_recv`.
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</span>future.as_mut().enable();
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<span class="kw">if let </span><span class="prelude-val">Some</span>(msg) = <span class="self">self</span>.try_recv() {
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<span class="kw">return </span>msg;
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}
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<span class="comment">// Wait for a call to `notify_one`.
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//
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// This uses `.as_mut()` to avoid consuming the future,
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// which lets us call `Pin::set` below.
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</span>future.as_mut().<span class="kw">await</span>;
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<span class="comment">// Reset the future in case another call to
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// `try_recv` got the message before us.
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</span>future.set(<span class="self">self</span>.notify_on_sent.notified());
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}
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}
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}</code></pre></div></div></details><h2 id="implementations" class="section-header">Implementations<a href="#implementations" class="anchor">§</a></h2><div id="implementations-list"><details class="toggle implementors-toggle" open><summary><section id="impl-Notify" class="impl"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#473-833">Source</a><a href="#impl-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.new" class="method"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#483-488">Source</a><h4 class="code-header">pub fn <a href="#method.new" class="fn">new</a>() -> <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h4></section></summary><div class="docblock"><p>Create a new <code>Notify</code>, initialized without a permit.</p>
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<h5 id="examples-1"><a class="doc-anchor" href="#examples-1">§</a>Examples</h5>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
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<span class="kw">let </span>notify = Notify::new();</code></pre></div></div></details><details class="toggle method-toggle" open><summary><section id="method.const_new" class="method"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#508-513">Source</a><h4 class="code-header">pub const fn <a href="#method.const_new" class="fn">const_new</a>() -> <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h4></section></summary><div class="docblock"><p>Create a new <code>Notify</code>, initialized without a permit.</p>
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<p>When using the <code>tracing</code> <a href="../index.html#unstable-features" title="mod tokio">unstable feature</a>, a <code>Notify</code> created with
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<code>const_new</code> will not be instrumented. As such, it will not be visible
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in <a href="https://github.com/tokio-rs/console"><code>tokio-console</code></a>. Instead, <a href="struct.Notify.html#method.new" title="associated function tokio::sync::Notify::new"><code>Notify::new</code></a> should be used to create
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an instrumented object if that is needed.</p>
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<h5 id="examples-2"><a class="doc-anchor" href="#examples-2">§</a>Examples</h5>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
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<span class="kw">static </span>NOTIFY: Notify = Notify::const_new();</code></pre></div></div></details><details class="toggle method-toggle" open><summary><section id="method.notified" class="method"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#565-575">Source</a><h4 class="code-header">pub fn <a href="#method.notified" class="fn">notified</a>(&self) -> <a class="struct" href="futures/struct.Notified.html" title="struct tokio::sync::futures::Notified">Notified</a><'_> <a href="#" class="tooltip" data-notable-ty="Notified<'_>">ⓘ</a></h4></section></summary><div class="docblock"><p>Wait for a notification.</p>
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<p>Equivalent to:</p>
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<div class="example-wrap ignore"><a href="#" class="tooltip" title="This example is not tested">ⓘ</a><pre class="rust rust-example-rendered"><code><span class="kw">async fn </span>notified(<span class="kw-2">&</span><span class="self">self</span>);</code></pre></div>
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<p>Each <code>Notify</code> value holds a single permit. If a permit is available from
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an earlier call to <a href="struct.Notify.html#method.notify_one" title="method tokio::sync::Notify::notify_one"><code>notify_one()</code></a>, then <code>notified().await</code> will complete
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immediately, consuming that permit. Otherwise, <code>notified().await</code> waits
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for a permit to be made available by the next call to <code>notify_one()</code>.</p>
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<p>The <code>Notified</code> future is not guaranteed to receive wakeups from calls to
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<code>notify_one()</code> if it has not yet been polled. See the documentation for
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<a href="futures/struct.Notified.html#method.enable" title="method tokio::sync::futures::Notified::enable"><code>Notified::enable()</code></a> for more details.</p>
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<p>The <code>Notified</code> future is guaranteed to receive wakeups from
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<code>notify_waiters()</code> as soon as it has been created, even if it has not
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yet been polled.</p>
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<h5 id="cancel-safety"><a class="doc-anchor" href="#cancel-safety">§</a>Cancel safety</h5>
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<p>This method uses a queue to fairly distribute notifications in the order
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they were requested. Cancelling a call to <code>notified</code> makes you lose your
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place in the queue.</p>
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<h5 id="examples-3"><a class="doc-anchor" href="#examples-3">§</a>Examples</h5>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
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<span class="kw">use </span>std::sync::Arc;
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<span class="kw">let </span>notify = Arc::new(Notify::new());
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<span class="kw">let </span>notify2 = notify.clone();
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tokio::spawn(<span class="kw">async move </span>{
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notify2.notified().<span class="kw">await</span>;
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<span class="macro">println!</span>(<span class="string">"received notification"</span>);
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});
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<span class="macro">println!</span>(<span class="string">"sending notification"</span>);
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notify.notify_one();</code></pre></div></div></details><details class="toggle method-toggle" open><summary><section id="method.notified_owned" class="method"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#613-623">Source</a><h4 class="code-header">pub fn <a href="#method.notified_owned" class="fn">notified_owned</a>(self: <a class="struct" href="https://doc.rust-lang.org/1.93.1/alloc/sync/struct.Arc.html" title="struct alloc::sync::Arc">Arc</a><Self>) -> <a class="struct" href="futures/struct.OwnedNotified.html" title="struct tokio::sync::futures::OwnedNotified">OwnedNotified</a> <a href="#" class="tooltip" data-notable-ty="OwnedNotified">ⓘ</a></h4></section></summary><div class="docblock"><p>Wait for a notification with an owned <code>Future</code>.</p>
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<p>Unlike <a href="struct.Notify.html#method.notified" title="method tokio::sync::Notify::notified"><code>Self::notified</code></a> which returns a future tied to the <code>Notify</code>’s
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lifetime, <code>notified_owned</code> creates a self-contained future that owns its
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notification state, making it safe to move between threads.</p>
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<p>See <a href="struct.Notify.html#method.notified" title="method tokio::sync::Notify::notified"><code>Self::notified</code></a> for more details.</p>
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<h5 id="cancel-safety-1"><a class="doc-anchor" href="#cancel-safety-1">§</a>Cancel safety</h5>
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<p>This method uses a queue to fairly distribute notifications in the order
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they were requested. Cancelling a call to <code>notified_owned</code> makes you lose your
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place in the queue.</p>
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<h5 id="examples-4"><a class="doc-anchor" href="#examples-4">§</a>Examples</h5>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc;
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<span class="kw">use </span>tokio::sync::Notify;
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<span class="kw">let </span>notify = Arc::new(Notify::new());
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||
<span class="kw">for _ in </span><span class="number">0</span>..<span class="number">10 </span>{
|
||
<span class="kw">let </span>notified = notify.clone().notified_owned();
|
||
tokio::spawn(<span class="kw">async move </span>{
|
||
notified.<span class="kw">await</span>;
|
||
<span class="macro">println!</span>(<span class="string">"received notification"</span>);
|
||
});
|
||
}
|
||
|
||
<span class="macro">println!</span>(<span class="string">"sending notification"</span>);
|
||
notify.notify_waiters();</code></pre></div></div></details><details class="toggle method-toggle" open><summary><section id="method.notify_one" class="method"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#660-662">Source</a><h4 class="code-header">pub fn <a href="#method.notify_one" class="fn">notify_one</a>(&self)</h4></section></summary><div class="docblock"><p>Notifies the first waiting task.</p>
|
||
<p>If a task is currently waiting, that task is notified. Otherwise, a
|
||
permit is stored in this <code>Notify</code> value and the <strong>next</strong> call to
|
||
<a href="struct.Notify.html#method.notified" title="method tokio::sync::Notify::notified"><code>notified().await</code></a> will complete immediately consuming the permit made
|
||
available by this call to <code>notify_one()</code>.</p>
|
||
<p>At most one permit may be stored by <code>Notify</code>. Many sequential calls to
|
||
<code>notify_one</code> will result in a single permit being stored. The next call to
|
||
<code>notified().await</code> will complete immediately, but the one after that
|
||
will wait.</p>
|
||
<h5 id="examples-5"><a class="doc-anchor" href="#examples-5">§</a>Examples</h5>
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
|
||
<span class="kw">use </span>std::sync::Arc;
|
||
|
||
<span class="kw">let </span>notify = Arc::new(Notify::new());
|
||
<span class="kw">let </span>notify2 = notify.clone();
|
||
|
||
tokio::spawn(<span class="kw">async move </span>{
|
||
notify2.notified().<span class="kw">await</span>;
|
||
<span class="macro">println!</span>(<span class="string">"received notification"</span>);
|
||
});
|
||
|
||
<span class="macro">println!</span>(<span class="string">"sending notification"</span>);
|
||
notify.notify_one();</code></pre></div></div></details><details class="toggle method-toggle" open><summary><section id="method.notify_last" class="method"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#673-675">Source</a><h4 class="code-header">pub fn <a href="#method.notify_last" class="fn">notify_last</a>(&self)</h4></section></summary><div class="docblock"><p>Notifies the last waiting task.</p>
|
||
<p>This function behaves similar to <code>notify_one</code>. The only difference is that it wakes
|
||
the most recently added waiter instead of the oldest waiter.</p>
|
||
<p>Check the <a href="struct.Notify.html#method.notify_one" title="method tokio::sync::Notify::notify_one"><code>notify_one()</code></a> documentation for more info and
|
||
examples.</p>
|
||
</div></details><details class="toggle method-toggle" open><summary><section id="method.notify_waiters" class="method"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#743-745">Source</a><h4 class="code-header">pub fn <a href="#method.notify_waiters" class="fn">notify_waiters</a>(&self)</h4></section></summary><div class="docblock"><p>Notifies all waiting tasks.</p>
|
||
<p>If a task is currently waiting, that task is notified. Unlike with
|
||
<code>notify_one()</code>, no permit is stored to be used by the next call to
|
||
<code>notified().await</code>. The purpose of this method is to notify all
|
||
already registered waiters. Registering for notification is done by
|
||
acquiring an instance of the <code>Notified</code> future via calling <code>notified()</code>.</p>
|
||
<h5 id="examples-6"><a class="doc-anchor" href="#examples-6">§</a>Examples</h5>
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::Notify;
|
||
<span class="kw">use </span>std::sync::Arc;
|
||
|
||
<span class="kw">let </span>notify = Arc::new(Notify::new());
|
||
<span class="kw">let </span>notify2 = notify.clone();
|
||
|
||
<span class="kw">let </span>notified1 = notify.notified();
|
||
<span class="kw">let </span>notified2 = notify.notified();
|
||
|
||
<span class="kw">let </span>handle = tokio::spawn(<span class="kw">async move </span>{
|
||
<span class="macro">println!</span>(<span class="string">"sending notifications"</span>);
|
||
notify2.notify_waiters();
|
||
});
|
||
|
||
notified1.<span class="kw">await</span>;
|
||
notified2.<span class="kw">await</span>;
|
||
<span class="macro">println!</span>(<span class="string">"received notifications"</span>);</code></pre></div></div></details></div></details></div><h2 id="trait-implementations" class="section-header">Trait Implementations<a href="#trait-implementations" class="anchor">§</a></h2><div id="trait-implementations-list"><details class="toggle implementors-toggle" open><summary><section id="impl-Debug-for-Notify" class="impl"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#201">Source</a><a href="#impl-Debug-for-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.fmt" class="method trait-impl"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#201">Source</a><a href="#method.fmt" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/fmt/trait.Debug.html#tymethod.fmt" class="fn">fmt</a>(&self, f: &mut <a class="struct" href="https://doc.rust-lang.org/1.93.1/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a><'_>) -> <a class="type" href="https://doc.rust-lang.org/1.93.1/core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></h4></section></summary><div class='docblock'>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/1.93.1/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Default-for-Notify" class="impl"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#835-839">Source</a><a href="#impl-Default-for-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/default/trait.Default.html" title="trait core::default::Default">Default</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.default" class="method trait-impl"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#836-838">Source</a><a href="#method.default" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/default/trait.Default.html#tymethod.default" class="fn">default</a>() -> <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h4></section></summary><div class='docblock'>Returns the “default value” for a type. <a href="https://doc.rust-lang.org/1.93.1/core/default/trait.Default.html#tymethod.default">Read more</a></div></details></div></details><section id="impl-RefUnwindSafe-for-Notify" class="impl"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#842">Source</a><a href="#impl-RefUnwindSafe-for-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/panic/unwind_safe/trait.RefUnwindSafe.html" title="trait core::panic::unwind_safe::RefUnwindSafe">RefUnwindSafe</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section><section id="impl-UnwindSafe-for-Notify" class="impl"><a class="src rightside" href="../../src/tokio/sync/notify.rs.html#841">Source</a><a href="#impl-UnwindSafe-for-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/panic/unwind_safe/trait.UnwindSafe.html" title="trait core::panic::unwind_safe::UnwindSafe">UnwindSafe</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section></div><h2 id="synthetic-implementations" class="section-header">Auto Trait Implementations<a href="#synthetic-implementations" class="anchor">§</a></h2><div id="synthetic-implementations-list"><section id="impl-Freeze-for-Notify" class="impl"><a href="#impl-Freeze-for-Notify" class="anchor">§</a><h3 class="code-header">impl !<a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Freeze.html" title="trait core::marker::Freeze">Freeze</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section><section id="impl-Send-for-Notify" class="impl"><a href="#impl-Send-for-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section><section id="impl-Sync-for-Notify" class="impl"><a href="#impl-Sync-for-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section><section id="impl-Unpin-for-Notify" class="impl"><a href="#impl-Unpin-for-Notify" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a> for <a class="struct" href="struct.Notify.html" title="struct tokio::sync::Notify">Notify</a></h3></section></div><h2 id="blanket-implementations" class="section-header">Blanket Implementations<a href="#blanket-implementations" class="anchor">§</a></h2><div id="blanket-implementations-list"><details class="toggle implementors-toggle"><summary><section id="impl-Any-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/any.rs.html#138">Source</a><a href="#impl-Any-for-T" class="anchor">§</a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/any/trait.Any.html" title="trait core::any::Any">Any</a> for T<div class="where">where
|
||
T: 'static + ?<a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.type_id" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/any.rs.html#139">Source</a><a href="#method.type_id" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/any/trait.Any.html#tymethod.type_id" class="fn">type_id</a>(&self) -> <a class="struct" href="https://doc.rust-lang.org/1.93.1/core/any/struct.TypeId.html" title="struct core::any::TypeId">TypeId</a></h4></section></summary><div class='docblock'>Gets the <code>TypeId</code> of <code>self</code>. <a href="https://doc.rust-lang.org/1.93.1/core/any/trait.Any.html#tymethod.type_id">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-Borrow%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/borrow.rs.html#212">Source</a><a href="#impl-Borrow%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/borrow/trait.Borrow.html" title="trait core::borrow::Borrow">Borrow</a><T> for T<div class="where">where
|
||
T: ?<a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.borrow" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/borrow.rs.html#214">Source</a><a href="#method.borrow" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/borrow/trait.Borrow.html#tymethod.borrow" class="fn">borrow</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/1.93.1/std/primitive.reference.html">&T</a></h4></section></summary><div class='docblock'>Immutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.93.1/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-BorrowMut%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/borrow.rs.html#221">Source</a><a href="#impl-BorrowMut%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/borrow/trait.BorrowMut.html" title="trait core::borrow::BorrowMut">BorrowMut</a><T> for T<div class="where">where
|
||
T: ?<a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.borrow_mut" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/borrow.rs.html#222">Source</a><a href="#method.borrow_mut" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut" class="fn">borrow_mut</a>(&mut self) -> <a class="primitive" href="https://doc.rust-lang.org/1.93.1/std/primitive.reference.html">&mut T</a></h4></section></summary><div class='docblock'>Mutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.93.1/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-From%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#785">Source</a><a href="#impl-From%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.From.html" title="trait core::convert::From">From</a><T> for T</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.from" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#788">Source</a><a href="#method.from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.From.html#tymethod.from" class="fn">from</a>(t: T) -> T</h4></section></summary><div class="docblock"><p>Returns the argument unchanged.</p>
|
||
</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-Into%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#767-769">Source</a><a href="#impl-Into%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><U> for T<div class="where">where
|
||
U: <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.From.html" title="trait core::convert::From">From</a><T>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.into" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#777">Source</a><a href="#method.into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.Into.html#tymethod.into" class="fn">into</a>(self) -> U</h4></section></summary><div class="docblock"><p>Calls <code>U::from(self)</code>.</p>
|
||
<p>That is, this conversion is whatever the implementation of
|
||
<code><a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.From.html" title="trait core::convert::From">From</a><T> for U</code> chooses to do.</p>
|
||
</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-TryFrom%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#827-829">Source</a><a href="#impl-TryFrom%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U> for T<div class="where">where
|
||
U: <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><T>,</div></h3></section></summary><div class="impl-items"><details class="toggle" open><summary><section id="associatedtype.Error-1" class="associatedtype trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#831">Source</a><a href="#associatedtype.Error-1" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html#associatedtype.Error" class="associatedtype">Error</a> = <a class="enum" href="https://doc.rust-lang.org/1.93.1/core/convert/enum.Infallible.html" title="enum core::convert::Infallible">Infallible</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="toggle method-toggle" open><summary><section id="method.try_from" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#834">Source</a><a href="#method.try_from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html#tymethod.try_from" class="fn">try_from</a>(value: U) -> <a class="enum" href="https://doc.rust-lang.org/1.93.1/core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, <T as <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U>>::<a class="associatedtype" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-TryInto%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#811-813">Source</a><a href="#impl-TryInto%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryInto.html" title="trait core::convert::TryInto">TryInto</a><U> for T<div class="where">where
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U: <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>,</div></h3></section></summary><div class="impl-items"><details class="toggle" open><summary><section id="associatedtype.Error" class="associatedtype trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#815">Source</a><a href="#associatedtype.Error" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryInto.html#associatedtype.Error" class="associatedtype">Error</a> = <U as <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="associatedtype" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="toggle method-toggle" open><summary><section id="method.try_into" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#818">Source</a><a href="#method.try_into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryInto.html#tymethod.try_into" class="fn">try_into</a>(self) -> <a class="enum" href="https://doc.rust-lang.org/1.93.1/core/result/enum.Result.html" title="enum core::result::Result">Result</a><U, <U as <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="associatedtype" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details></div><script type="text/json" id="notable-traits-data">{"Notified<'_>":"<h3>Notable traits for <code><a class=\"struct\" href=\"futures/struct.Notified.html\" title=\"struct tokio::sync::futures::Notified\">Notified</a><'_></code></h3><pre><code><div class=\"where\">impl <a class=\"trait\" href=\"https://doc.rust-lang.org/1.93.1/core/future/future/trait.Future.html\" title=\"trait core::future::future::Future\">Future</a> for <a class=\"struct\" href=\"futures/struct.Notified.html\" title=\"struct tokio::sync::futures::Notified\">Notified</a><'_></div><div class=\"where\"> type <a href=\"https://doc.rust-lang.org/1.93.1/core/future/future/trait.Future.html#associatedtype.Output\" class=\"associatedtype\">Output</a> = <a class=\"primitive\" href=\"https://doc.rust-lang.org/1.93.1/std/primitive.unit.html\">()</a>;</div>","OwnedNotified":"<h3>Notable traits for <code><a class=\"struct\" href=\"futures/struct.OwnedNotified.html\" title=\"struct tokio::sync::futures::OwnedNotified\">OwnedNotified</a></code></h3><pre><code><div class=\"where\">impl <a class=\"trait\" href=\"https://doc.rust-lang.org/1.93.1/core/future/future/trait.Future.html\" title=\"trait core::future::future::Future\">Future</a> for <a class=\"struct\" href=\"futures/struct.OwnedNotified.html\" title=\"struct tokio::sync::futures::OwnedNotified\">OwnedNotified</a></div><div class=\"where\"> type <a href=\"https://doc.rust-lang.org/1.93.1/core/future/future/trait.Future.html#associatedtype.Output\" class=\"associatedtype\">Output</a> = <a class=\"primitive\" href=\"https://doc.rust-lang.org/1.93.1/std/primitive.unit.html\">()</a>;</div>"}</script></section></div></main></body></html> |