17 lines
5.4 KiB
HTML
17 lines
5.4 KiB
HTML
<!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="Thread-safe, non-blocking, “first one wins” flavor of `OnceCell`."><title>once_cell::race - 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="once_cell" 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 mod"><!--[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="#">Module race</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../once_cell/index.html">once_<wbr>cell</a><span class="version">1.21.3</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Module race</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#atomic-orderings" title="Atomic orderings">Atomic orderings</a></li></ul><h3><a href="#structs">Module Items</a></h3><ul class="block"><li><a href="#structs" title="Structs">Structs</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="../index.html">In crate once_<wbr>cell</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">once_cell</a></div><h1>Module <span>race</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/once_cell/race.rs.html#1-498">Source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Thread-safe, non-blocking, “first one wins” flavor of <code>OnceCell</code>.</p>
|
||
<p>If two threads race to initialize a type from the <code>race</code> module, they
|
||
don’t block, execute initialization function together, but only one of
|
||
them stores the result.</p>
|
||
<p>This module does not require <code>std</code> feature.</p>
|
||
<h2 id="atomic-orderings"><a class="doc-anchor" href="#atomic-orderings">§</a>Atomic orderings</h2>
|
||
<p>All types in this module use <code>Acquire</code> and <code>Release</code>
|
||
<a href="https://doc.rust-lang.org/1.93.1/core/sync/atomic/enum.Ordering.html" title="enum core::sync::atomic::Ordering">atomic orderings</a> for all their operations. While this is not
|
||
strictly necessary for types other than <code>OnceBox</code>, it is useful for users as
|
||
it allows them to be certain that after <code>get</code> or <code>get_or_init</code> returns on
|
||
one thread, any side-effects caused by the setter thread prior to them
|
||
calling <code>set</code> or <code>get_or_init</code> will be made visible to that thread; without
|
||
it, it’s possible for it to appear as if they haven’t happened yet from the
|
||
getter thread’s perspective. This is an acceptable tradeoff to make since
|
||
<code>Acquire</code> and <code>Release</code> have very little performance overhead on most
|
||
architectures versus <code>Relaxed</code>.</p>
|
||
</div></details><h2 id="structs" class="section-header">Structs<a href="#structs" class="anchor">§</a></h2><dl class="item-table"><dt><a class="struct" href="struct.OnceBool.html" title="struct once_cell::race::OnceBool">Once<wbr>Bool</a></dt><dd>A thread-safe cell which can be written to only once.</dd><dt><a class="struct" href="struct.OnceBox.html" title="struct once_cell::race::OnceBox">OnceBox</a></dt><dd>A thread-safe cell which can be written to only once.</dd><dt><a class="struct" href="struct.OnceNonZeroUsize.html" title="struct once_cell::race::OnceNonZeroUsize">Once<wbr>NonZero<wbr>Usize</a></dt><dd>A thread-safe cell which can be written to only once.</dd><dt><a class="struct" href="struct.OnceRef.html" title="struct once_cell::race::OnceRef">OnceRef</a></dt><dd>A thread-safe cell which can be written to only once.</dd></dl></section></div></main></body></html> |