wasmer/rustdoc/rayon/fn.spawn.html
2019-09-06 15:57:44 -07:00

40 lines
7.2 KiB
HTML
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!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="API documentation for the Rust `spawn` fn in crate `rayon`."><meta name="keywords" content="rust, rustlang, rust-lang, spawn"><title>rayon::spawn - Rust</title><link rel="stylesheet" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../dark.css"><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><script src="../storage.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="shortcut icon" href="../favicon.ico"><style type="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><body class="rustdoc fn"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">&#9776;</div><a href='../rayon/index.html'><div class='logo-container'><img src='../rust-logo.png' alt='logo'></div></a><div class="sidebar-elems"><p class='location'><a href='index.html'>rayon</a></p><script>window.sidebarCurrent = {name: 'spawn', ty: 'fn', relpath: ''};</script><script defer src="sidebar-items.js"></script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press S to search, ? for more options…" type="search"></div><a id="settings-menu" href="../settings.html"><img src="../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class='fqn'><span class='out-of-band'><span id='render-detail'><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class='inner'>&#x2212;</span>]</a></span><a class='srclink' href='../src/rayon_core/spawn/mod.rs.html#61-67' title='goto source code'>[src]</a></span><span class='in-band'>Function <a href='index.html'>rayon</a>::<wbr><a class="fn" href=''>spawn</a></span></h1><pre class='rust fn'>pub fn spawn&lt;F&gt;(func: F) <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>() + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> + 'static,&nbsp;</span></pre><div class='docblock'><p>Fires off a task into the Rayon threadpool in the &quot;static&quot; or
&quot;global&quot; scope. Just like a standard thread, this task is not
tied to the current stack frame, and hence it cannot hold any
references other than those with <code>'static</code> lifetime. If you want
to spawn a task that references stack data, use <a href="fn.scope.html">the <code>scope()</code>
function</a> to create a scope.</p>
<p>Since tasks spawned with this function cannot hold references into
the enclosing stack frame, you almost certainly want to use a
<code>move</code> closure as their argument (otherwise, the closure will
typically hold references to any variables from the enclosing
function that you happen to use).</p>
<p>This API assumes that the closure is executed purely for its
side-effects (i.e., it might send messages, modify data protected
by a mutex, or some such thing). If you want to compute a result,
consider <code>spawn_future()</code>.</p>
<p>There is no guaranteed order of execution for spawns, given that
other threads may steal tasks at any time. However, they are
generally prioritized in a LIFO order on the thread from which
they were spawned. Other threads always steal from the other end of
the deque, like FIFO order. The idea is that &quot;recent&quot; tasks are
most likely to be fresh in the local CPU's cache, while other
threads can steal older &quot;stale&quot; tasks. For an alternate approach,
consider <a href="fn.spawn_fifo.html"><code>spawn_fifo()</code></a> instead.</p>
<h1 id="panic-handling" class="section-header"><a href="#panic-handling">Panic handling</a></h1>
<p>If this closure should panic, the resulting panic will be
propagated to the panic handler registered in the <code>ThreadPoolBuilder</code>,
if any. See <a href="struct.ThreadPoolBuilder.html#method.panic_handler"><code>ThreadPoolBuilder::panic_handler()</code></a> for more
details.</p>
<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
<p>This code creates a Rayon task that increments a global counter.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">sync</span>::<span class="ident">atomic</span>::{<span class="ident">AtomicUsize</span>, <span class="ident">Ordering</span>, <span class="ident">ATOMIC_USIZE_INIT</span>};
<span class="kw">static</span> <span class="ident">GLOBAL_COUNTER</span>: <span class="ident">AtomicUsize</span> <span class="op">=</span> <span class="ident">ATOMIC_USIZE_INIT</span>;
<span class="ident">rayon</span>::<span class="ident">spawn</span>(<span class="kw">move</span> <span class="op">|</span><span class="op">|</span> {
<span class="ident">GLOBAL_COUNTER</span>.<span class="ident">fetch_add</span>(<span class="number">1</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>);
});</pre></div>
</div></section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd></kbd></dt><dd>Move up in search results</dd><dt><kbd></kbd></dt><dd>Move down in search results</dd><dt><kbd></kbd></dt><dd>Switch tab</dd><dt><kbd>&#9166;</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g., <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g., <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g., <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../";window.currentCrate = "rayon";</script><script src="../aliases.js"></script><script src="../main.js"></script><script defer src="../search-index.js"></script></body></html>