| <!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="Strategies for protecting the reference counts."><meta name="keywords" content="rust, rustlang, rust-lang, strategy"><title>arc_swap::strategy - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.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]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../arc_swap/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../arc_swap/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Module strategy</a></h2><div class="sidebar-elems"><section><ul class="block"><li><a href="#traits">Traits</a></li><li><a href="#types">Type Definitions</a></li></ul></section></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Module <a href="../index.html">arc_swap</a>::<wbr><a class="mod" href="#">strategy</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../src/arc_swap/strategy/mod.rs.html#1-160">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Strategies for protecting the reference counts.</p> |
| <p>There are multiple algorithms how to protect the reference counts while they’re being updated |
| by multiple threads, each with its own set of pros and cons. The <a href="type.DefaultStrategy.html" title="DefaultStrategy"><code>DefaultStrategy</code></a> is used by |
| default and should generally be the least surprising option. It is possible to pick a different |
| strategy.</p> |
| <p>For now, the traits in here are sealed and don’t expose any methods to the users of the crate. |
| This is because we are not confident about the details just yet. In the future it may be |
| possible for downstream users to implement their own, but for now it is only so users can |
| choose one of the provided.</p> |
| <p>It is expected that future strategies would come with different capabilities and limitations. |
| In particular, some that are not “tight” in the cleanup (delay the cleanup) or not support the |
| compare and swap operations.</p> |
| <p>Currently, we have these strategies:</p> |
| <ul> |
| <li><a href="type.DefaultStrategy.html" title="DefaultStrategy"><code>DefaultStrategy</code></a> (this one is used implicitly)</li> |
| <li>[<code>RwLock<()></code>][std::sync::RwLock]</li> |
| </ul> |
| <h2 id="testing"><a href="#testing">Testing</a></h2> |
| <p>Formally, the [<code>RwLock<()></code>][std::sync::RwLock] may be used as a strategy too. It doesn’t have |
| the performance characteristics or lock-free guarantees of the others, but it is much simpler |
| and contains less <code>unsafe</code> code (actually, less code altogether). Therefore, it can be used for |
| testing purposes and cross-checking.</p> |
| <p>Note that generally, using [<code>RwLock<Arc<T>></code>][std::sync::RwLock] is likely to be better |
| performance wise. So if the goal is to not use third-party unsafe code, only the one in |
| [<code>std</code>], that is the better option. This is provided mostly for investigation and testing of |
| <a href="../type.ArcSwap.html"><code>ArcSwap</code></a> itself or algorithms written to use <a href="../type.ArcSwap.html"><code>ArcSwap</code></a>.</p> |
| <p><em>This is not meant to be used in production code</em>.</p> |
| </div></details><h2 id="traits" class="small-section-header"><a href="#traits">Traits</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="trait" href="trait.CaS.html" title="arc_swap::strategy::CaS trait">CaS</a></div><div class="item-right docblock-short">An extension of the <a href="trait.Strategy.html" title="Strategy"><code>Strategy</code></a>, allowing for compare and swap operation.</div></div><div class="item-row"><div class="item-left module-item"><a class="trait" href="trait.Strategy.html" title="arc_swap::strategy::Strategy trait">Strategy</a></div><div class="item-right docblock-short">A strategy for protecting the reference counted pointer <code>T</code>.</div></div></div><h2 id="types" class="small-section-header"><a href="#types">Type Definitions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="type" href="type.DefaultStrategy.html" title="arc_swap::strategy::DefaultStrategy type">DefaultStrategy</a></div><div class="item-right docblock-short">The default strategy.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="arc_swap" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
