<!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 `Builder` struct in crate `std`."> <meta name="keywords" content="rust, rustlang, rust-lang, Builder"> <title>std::thread::Builder - 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="../../main.css" id="themeStyle"> <script src="../../storage.js"></script> <link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"> </head> <body class="rustdoc struct"> <!--[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">☰</div> <a href='../../std/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a> <p class='location'>Struct Builder</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#methods">Methods</a><div class="sidebar-links"><a href="#method.new">new</a><a href="#method.name">name</a><a href="#method.stack_size">stack_size</a><a href="#method.spawn">spawn</a></div><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Debug">Debug</a></div></div><p class='location'><a href='../index.html'>std</a>::<wbr><a href='index.html'>thread</a></p><script>window.sidebarCurrent = {name: 'Builder', ty: 'struct', 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"> <input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"> </div> </form> </nav> <section id='main' class="content"> <h1 class='fqn'><span class='in-band'>Struct <a href='../index.html'>std</a>::<wbr><a href='index.html'>thread</a>::<wbr><a class="struct" href=''>Builder</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version 1.0.0'>1.0.0</span><span id='render-detail'> <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs"> [<span class='inner'>−</span>] </a> </span><a class='srclink' href='../../src/std/thread/mod.rs.html#259-264' title='goto source code'>[src]</a></span></h1> <pre class='rust struct'>pub struct Builder { /* fields omitted */ }</pre><div class='docblock'><p>Thread factory, which can be used in order to configure the properties of a new thread.</p> <p>Methods can be chained on it in order to configure it.</p> <p>The two configurations available are:</p> <ul> <li><a href="../../std/thread/struct.Builder.html#method.name"><code>name</code></a>: specifies an <a href="./index.html#naming-threads">associated name for the thread</a></li> <li><a href="../../std/thread/struct.Builder.html#method.stack_size"><code>stack_size</code></a>: specifies the <a href="./index.html#stack-size">desired stack size for the thread</a></li> </ul> <p>The <a href="../../std/thread/struct.Builder.html#method.spawn"><code>spawn</code></a> method will take ownership of the builder and create an <a href="../../std/io/type.Result.html"><code>io::Result</code></a> to the thread handle with the given configuration.</p> <p>The <a href="../../std/thread/fn.spawn.html"><code>thread::spawn</code></a> free function uses a <code>Builder</code> with default configuration and <a href="../../std/result/enum.Result.html#method.unwrap"><code>unwrap</code></a>s its return value.</p> <p>You may want to use <a href="../../std/thread/struct.Builder.html#method.spawn"><code>spawn</code></a> instead of <a href="../../std/thread/fn.spawn.html"><code>thread::spawn</code></a>, when you want to recover from a failure to launch a thread, indeed the free function will panick where the <code>Builder</code> method will return a <a href="../../std/io/type.Result.html"><code>io::Result</code></a>.</p> <h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1> <pre class="rust rust-example-rendered"> <span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>; <span class="kw">let</span> <span class="ident">builder</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">Builder</span>::<span class="ident">new</span>(); <span class="kw">let</span> <span class="ident">handler</span> <span class="op">=</span> <span class="ident">builder</span>.<span class="ident">spawn</span>(<span class="op">||</span> { <span class="comment">// thread code</span> }).<span class="ident">unwrap</span>(); <span class="ident">handler</span>.<span class="ident">join</span>().<span class="ident">unwrap</span>();<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Athread%3B%0A%0Alet%20builder%20%3D%20thread%3A%3ABuilder%3A%3Anew()%3B%0A%0Alet%20handler%20%3D%20builder.spawn(%7C%7C%20%7B%0A%20%20%20%20%2F%2F%20thread%20code%0A%7D).unwrap()%3B%0A%0Ahandler.join().unwrap()%3B%0A%7D">Run</a></pre> </div> <h2 id='methods' class='small-section-header'> Methods<a href='#methods' class='anchor'></a> </h2> <h3 id='impl' class='impl'><span class='in-band'><code>impl <a class="struct" href="../../std/thread/struct.Builder.html" title="struct std::thread::Builder">Builder</a></code><a href='#impl' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/std/thread/mod.rs.html#266-422' title='goto source code'>[src]</a></span></h3> <div class='impl-items'><h4 id='method.new' class="method"><span id='new.v' class='invisible'><code>pub fn <a href='#method.new' class='fnname'>new</a>() -> <a class="struct" href="../../std/thread/struct.Builder.html" title="struct std::thread::Builder">Builder</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/std/thread/mod.rs.html#286-291' title='goto source code'>[src]</a></span></h4> <div class='docblock'><p>Generates the base configuration for spawning a thread, from which configuration methods can be chained.</p> <h1 id="examples-1" class="section-header"><a href="#examples-1">Examples</a></h1> <pre class="rust rust-example-rendered"> <span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>; <span class="kw">let</span> <span class="ident">builder</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">Builder</span>::<span class="ident">new</span>() .<span class="ident">name</span>(<span class="string">"foo"</span>.<span class="ident">into</span>()) .<span class="ident">stack_size</span>(<span class="number">10</span>); <span class="kw">let</span> <span class="ident">handler</span> <span class="op">=</span> <span class="ident">builder</span>.<span class="ident">spawn</span>(<span class="op">||</span> { <span class="comment">// thread code</span> }).<span class="ident">unwrap</span>(); <span class="ident">handler</span>.<span class="ident">join</span>().<span class="ident">unwrap</span>();<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Athread%3B%0A%0Alet%20builder%20%3D%20thread%3A%3ABuilder%3A%3Anew()%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20.name(%22foo%22.into())%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20.stack_size(10)%3B%0A%0Alet%20handler%20%3D%20builder.spawn(%7C%7C%20%7B%0A%20%20%20%20%2F%2F%20thread%20code%0A%7D).unwrap()%3B%0A%0Ahandler.join().unwrap()%3B%0A%7D">Run</a></pre> </div><h4 id='method.name' class="method"><span id='name.v' class='invisible'><code>pub fn <a href='#method.name' class='fnname'>name</a>(self, name: <a class="struct" href="../../std/string/struct.String.html" title="struct std::string::String">String</a>) -> <a class="struct" href="../../std/thread/struct.Builder.html" title="struct std::thread::Builder">Builder</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/std/thread/mod.rs.html#318-321' title='goto source code'>[src]</a></span></h4> <div class='docblock'><p>Names the thread-to-be. Currently the name is used for identification only in panic messages.</p> <p>The name must not contain null bytes (<code>\0</code>).</p> <p>For more information about named threads, see <a href="./index.html#naming-threads">this module-level documentation</a>.</p> <h1 id="examples-2" class="section-header"><a href="#examples-2">Examples</a></h1> <pre class="rust rust-example-rendered"> <span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>; <span class="kw">let</span> <span class="ident">builder</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">Builder</span>::<span class="ident">new</span>() .<span class="ident">name</span>(<span class="string">"foo"</span>.<span class="ident">into</span>()); <span class="kw">let</span> <span class="ident">handler</span> <span class="op">=</span> <span class="ident">builder</span>.<span class="ident">spawn</span>(<span class="op">||</span> { <span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">thread</span>::<span class="ident">current</span>().<span class="ident">name</span>(), <span class="prelude-val">Some</span>(<span class="string">"foo"</span>)) }).<span class="ident">unwrap</span>(); <span class="ident">handler</span>.<span class="ident">join</span>().<span class="ident">unwrap</span>();<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Athread%3B%0A%0Alet%20builder%20%3D%20thread%3A%3ABuilder%3A%3Anew()%0A%20%20%20%20.name(%22foo%22.into())%3B%0A%0Alet%20handler%20%3D%20builder.spawn(%7C%7C%20%7B%0A%20%20%20%20assert_eq!(thread%3A%3Acurrent().name()%2C%20Some(%22foo%22))%0A%7D).unwrap()%3B%0A%0Ahandler.join().unwrap()%3B%0A%7D">Run</a></pre> </div><h4 id='method.stack_size' class="method"><span id='stack_size.v' class='invisible'><code>pub fn <a href='#method.stack_size' class='fnname'>stack_size</a>(self, size: <a class="primitive" href="../primitive.usize.html">usize</a>) -> <a class="struct" href="../../std/thread/struct.Builder.html" title="struct std::thread::Builder">Builder</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/std/thread/mod.rs.html#341-344' title='goto source code'>[src]</a></span></h4> <div class='docblock'><p>Sets the size of the stack (in bytes) for the new thread.</p> <p>The actual stack size may be greater than this value if the platform specifies minimal stack size.</p> <p>For more information about the stack size for threads, see <a href="./index.html#stack-size">this module-level documentation</a>.</p> <h1 id="examples-3" class="section-header"><a href="#examples-3">Examples</a></h1> <pre class="rust rust-example-rendered"> <span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>; <span class="kw">let</span> <span class="ident">builder</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">Builder</span>::<span class="ident">new</span>().<span class="ident">stack_size</span>(<span class="number">32</span> <span class="op">*</span> <span class="number">1024</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Athread%3B%0A%0Alet%20builder%20%3D%20thread%3A%3ABuilder%3A%3Anew().stack_size(32%20*%201024)%3B%0A%7D">Run</a></pre> </div><h4 id='method.spawn' class="method"><span id='spawn.v' class='invisible'><code>pub fn <a href='#method.spawn' class='fnname'>spawn</a><F, T>(self, f: F) -> <a class="type" href="../../std/io/type.Result.html" title="type std::io::Result">Result</a><<a class="struct" href="../../std/thread/struct.JoinHandle.html" title="struct std::thread::JoinHandle">JoinHandle</a><T>> <span class="where fmt-newline">where<br> F: <a class="trait" href="../../std/ops/trait.FnOnce.html" title="trait std::ops::FnOnce">FnOnce</a>() -> T,<br> F: <a class="trait" href="../../std/marker/trait.Send.html" title="trait std::marker::Send">Send</a> + 'static,<br> T: <a class="trait" href="../../std/marker/trait.Send.html" title="trait std::marker::Send">Send</a> + 'static, </span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/std/thread/mod.rs.html#384-421' title='goto source code'>[src]</a></span></h4> <div class='docblock'><p>Spawns a new thread by taking ownership of the <code>Builder</code>, and returns an <a href="../../std/io/type.Result.html"><code>io::Result</code></a> to its <a href="../../std/thread/struct.JoinHandle.html"><code>JoinHandle</code></a>.</p> <p>The spawned thread may outlive the caller (unless the caller thread is the main thread; the whole process is terminated when the main thread finishes). The join handle can be used to block on termination of the child thread, including recovering its panics.</p> <p>For a more complete documentation see <a href="../../std/thread/fn.spawn.html"><code>thread::spawn</code></a>.</p> <h1 id="errors" class="section-header"><a href="#errors">Errors</a></h1> <p>Unlike the <a href="../../std/thread/fn.spawn.html"><code>spawn</code></a> free function, this method yields an <a href="../../std/io/type.Result.html"><code>io::Result</code></a> to capture any failure to create the thread at the OS level.</p> <h1 id="panics" class="section-header"><a href="#panics">Panics</a></h1> <p>Panics if a thread name was set and it contained null bytes.</p> <h1 id="examples-4" class="section-header"><a href="#examples-4">Examples</a></h1> <pre class="rust rust-example-rendered"> <span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>; <span class="kw">let</span> <span class="ident">builder</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">Builder</span>::<span class="ident">new</span>(); <span class="kw">let</span> <span class="ident">handler</span> <span class="op">=</span> <span class="ident">builder</span>.<span class="ident">spawn</span>(<span class="op">||</span> { <span class="comment">// thread code</span> }).<span class="ident">unwrap</span>(); <span class="ident">handler</span>.<span class="ident">join</span>().<span class="ident">unwrap</span>();<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Athread%3B%0A%0Alet%20builder%20%3D%20thread%3A%3ABuilder%3A%3Anew()%3B%0A%0Alet%20handler%20%3D%20builder.spawn(%7C%7C%20%7B%0A%20%20%20%20%2F%2F%20thread%20code%0A%7D).unwrap()%3B%0A%0Ahandler.join().unwrap()%3B%0A%7D">Run</a></pre> </div></div> <h2 id='implementations' class='small-section-header'> Trait Implementations<a href='#implementations' class='anchor'></a> </h2> <h3 id='impl-Debug' class='impl'><span class='in-band'><code>impl <a class="trait" href="../../std/fmt/trait.Debug.html" title="trait std::fmt::Debug">Debug</a> for <a class="struct" href="../../std/thread/struct.Builder.html" title="struct std::thread::Builder">Builder</a></code><a href='#impl-Debug' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/std/thread/mod.rs.html#258' title='goto source code'>[src]</a></span></h3> <div class='impl-items'><h4 id='method.fmt' class="method"><span id='fmt.v' class='invisible'><code>fn <a href='../../std/fmt/trait.Debug.html#tymethod.fmt' class='fnname'>fmt</a>(&self, __arg_0: &mut <a class="struct" href="../../std/fmt/struct.Formatter.html" title="struct std::fmt::Formatter">Formatter</a>) -> <a class="type" href="../../std/fmt/type.Result.html" title="type std::fmt::Result">Result</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/std/thread/mod.rs.html#258' title='goto source code'>[src]</a></span></h4> <div class='docblock'><p>Formats the value using the given formatter. <a href="../../std/fmt/trait.Debug.html#tymethod.fmt">Read more</a></p> </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>⏎</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> </div> </div> </aside> <script> window.rootPath = "../../"; window.currentCrate = "std"; </script> <script src="../../main.js"></script> <script defer src="../../search-index.js"></script> </body> </html>