| <!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="A runtime for writing reliable network applications without compromising speed."><meta name="keywords" content="rust, rustlang, rust-lang, tokio"><title>tokio - 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="../crates.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 crate"><!--[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="../tokio/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="../tokio/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Crate tokio</a></h2><div class="sidebar-elems"><ul class="block"><li class="version">Version 1.24.0</li><li><a id="all-types" href="all.html">All Items</a></li></ul><section><ul class="block"><li><a href="#modules">Modules</a></li><li><a href="#macros">Macros</a></li><li><a href="#functions">Functions</a></li><li><a href="#attributes">Attribute Macros</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">Crate <a class="mod" href="#">tokio</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/tokio/lib.rs.html#1-633">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>A runtime for writing reliable network applications without compromising speed.</p> |
| <p>Tokio is an event-driven, non-blocking I/O platform for writing asynchronous |
| applications with the Rust programming language. At a high level, it |
| provides a few major components:</p> |
| <ul> |
| <li>Tools for <a href="#working-with-tasks">working with asynchronous tasks</a>, including |
| <a href="sync/index.html">synchronization primitives and channels</a> and <a href="time/index.html">timeouts, sleeps, and |
| intervals</a>.</li> |
| <li>APIs for <a href="#asynchronous-io">performing asynchronous I/O</a>, including <a href="net/index.html">TCP and UDP</a> sockets, |
| <a href="crate::fs">filesystem</a> operations, and <a href="crate::process">process</a> and <a href="crate::signal">signal</a> management.</li> |
| <li>A <a href="runtime/index.html">runtime</a> for executing asynchronous code, including a task scheduler, |
| an I/O driver backed by the operating system’s event queue (epoll, kqueue, |
| IOCP, etc…), and a high performance timer.</li> |
| </ul> |
| <p>Guide level documentation is found on the <a href="https://tokio.rs/tokio/tutorial">website</a>.</p> |
| <h2 id="a-tour-of-tokio"><a href="#a-tour-of-tokio">A Tour of Tokio</a></h2> |
| <p>Tokio consists of a number of modules that provide a range of functionality |
| essential for implementing asynchronous applications in Rust. In this |
| section, we will take a brief tour of Tokio, summarizing the major APIs and |
| their uses.</p> |
| <p>The easiest way to get started is to enable all features. Do this by |
| enabling the <code>full</code> feature flag:</p> |
| <div class="example-wrap"><pre class="language-toml"><code>tokio = { version = "1", features = ["full"] }</code></pre></div><h4 id="authoring-applications"><a href="#authoring-applications">Authoring applications</a></h4> |
| <p>Tokio is great for writing applications and most users in this case shouldn’t |
| worry too much about what features they should pick. If you’re unsure, we suggest |
| going with <code>full</code> to ensure that you don’t run into any road blocks while you’re |
| building your application.</p> |
| <h5 id="example"><a href="#example">Example</a></h5> |
| <p>This example shows the quickest way to get started with Tokio.</p> |
| <div class="example-wrap"><pre class="language-toml"><code>tokio = { version = "1", features = ["full"] }</code></pre></div><h4 id="authoring-libraries"><a href="#authoring-libraries">Authoring libraries</a></h4> |
| <p>As a library author your goal should be to provide the lightest weight crate |
| that is based on Tokio. To achieve this you should ensure that you only enable |
| the features you need. This allows users to pick up your crate without having |
| to enable unnecessary features.</p> |
| <h5 id="example-1"><a href="#example-1">Example</a></h5> |
| <p>This example shows how you may want to import features for a library that just |
| needs to <code>tokio::spawn</code> and use a <code>TcpStream</code>.</p> |
| <div class="example-wrap"><pre class="language-toml"><code>tokio = { version = "1", features = ["rt", "net"] }</code></pre></div><h3 id="working-with-tasks"><a href="#working-with-tasks">Working With Tasks</a></h3> |
| <p>Asynchronous programs in Rust are based around lightweight, non-blocking |
| units of execution called <a href="#working-with-tasks"><em>tasks</em></a>. The <a href="task/index.html"><code>tokio::task</code></a> module provides |
| important tools for working with tasks:</p> |
| <ul> |
| <li>The <a href="task/fn.spawn.html"><code>spawn</code></a> function and <a href="task/struct.JoinHandle.html"><code>JoinHandle</code></a> type, for scheduling a new task |
| on the Tokio runtime and awaiting the output of a spawned task, respectively,</li> |
| <li>Functions for <a href="task/index.html#blocking-and-yielding">running blocking operations</a> in an asynchronous |
| task context.</li> |
| </ul> |
| <p>The <a href="task/index.html"><code>tokio::task</code></a> module is present only when the “rt” feature flag |
| is enabled.</p> |
| <p>The <a href="sync/index.html"><code>tokio::sync</code></a> module contains synchronization primitives to use when |
| needing to communicate or share data. These include:</p> |
| <ul> |
| <li>channels (<a href="sync/oneshot/index.html"><code>oneshot</code></a>, <a href="sync/mpsc/index.html"><code>mpsc</code></a>, <a href="sync/watch/index.html"><code>watch</code></a>, and <a href="sync/broadcast/index.html"><code>broadcast</code></a>), for sending values |
| between tasks,</li> |
| <li>a non-blocking <a href="sync/struct.Mutex.html"><code>Mutex</code></a>, for controlling access to a shared, mutable |
| value,</li> |
| <li>an asynchronous <a href="sync/struct.Barrier.html"><code>Barrier</code></a> type, for multiple tasks to synchronize before |
| beginning a computation.</li> |
| </ul> |
| <p>The <code>tokio::sync</code> module is present only when the “sync” feature flag is |
| enabled.</p> |
| <p>The <a href="time/index.html"><code>tokio::time</code></a> module provides utilities for tracking time and |
| scheduling work. This includes functions for setting <a href="time/fn.timeout.html">timeouts</a> for |
| tasks, <a href="time/fn.sleep.html">sleeping</a> work to run in the future, or <a href="time/fn.interval.html">repeating an operation at an |
| interval</a>.</p> |
| <p>In order to use <code>tokio::time</code>, the “time” feature flag must be enabled.</p> |
| <p>Finally, Tokio provides a <em>runtime</em> for executing asynchronous tasks. Most |
| applications can use the <a href="attr.main.html"><code>#[tokio::main]</code></a> macro to run their code on the |
| Tokio runtime. However, this macro provides only basic configuration options. As |
| an alternative, the <a href="runtime/index.html"><code>tokio::runtime</code></a> module provides more powerful APIs for configuring |
| and managing runtimes. You should use that module if the <code>#[tokio::main]</code> macro doesn’t |
| provide the functionality you need.</p> |
| <p>Using the runtime requires the “rt” or “rt-multi-thread” feature flags, to |
| enable the current-thread <a href="runtime/index.html#current-thread-scheduler">single-threaded scheduler</a> and the <a href="runtime/index.html#multi-thread-scheduler">multi-thread |
| scheduler</a>, respectively. See the <a href="runtime/index.html#runtime-scheduler"><code>runtime</code> module |
| documentation</a> for details. In addition, the “macros” feature |
| flag enables the <code>#[tokio::main]</code> and <code>#[tokio::test]</code> attributes.</p> |
| <h3 id="cpu-bound-tasks-and-blocking-code"><a href="#cpu-bound-tasks-and-blocking-code">CPU-bound tasks and blocking code</a></h3> |
| <p>Tokio is able to concurrently run many tasks on a few threads by repeatedly |
| swapping the currently running task on each thread. However, this kind of |
| swapping can only happen at <code>.await</code> points, so code that spends a long time |
| without reaching an <code>.await</code> will prevent other tasks from running. To |
| combat this, Tokio provides two kinds of threads: Core threads and blocking threads.</p> |
| <p>The core threads are where all asynchronous code runs, and Tokio will by default |
| spawn one for each CPU core. You can use the environment variable <code>TOKIO_WORKER_THREADS</code> |
| to override the default value.</p> |
| <p>The blocking threads are spawned on demand, can be used to run blocking code |
| that would otherwise block other tasks from running and are kept alive when |
| not used for a certain amount of time which can be configured with <a href="runtime/struct.Builder.html#method.thread_keep_alive"><code>thread_keep_alive</code></a>. |
| Since it is not possible for Tokio to swap out blocking tasks, like it |
| can do with asynchronous code, the upper limit on the number of blocking |
| threads is very large. These limits can be configured on the <a href="runtime/struct.Builder.html"><code>Builder</code></a>.</p> |
| <p>To spawn a blocking task, you should use the <a href="task/fn.spawn_blocking.html"><code>spawn_blocking</code></a> function.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="comment">// This is running on a core thread. |
| |
| </span><span class="kw">let </span>blocking_task = tokio::task::spawn_blocking(|| { |
| <span class="comment">// This is running on a blocking thread. |
| // Blocking here is ok. |
| </span>}); |
| |
| <span class="comment">// We can wait for the blocking task like this: |
| // If the blocking task panics, the unwrap below will propagate the |
| // panic. |
| </span>blocking_task.<span class="kw">await</span>.unwrap(); |
| }</code></pre></div> |
| <p>If your code is CPU-bound and you wish to limit the number of threads used |
| to run it, you should use a separate thread pool dedicated to CPU bound tasks. |
| For example, you could consider using the <a href="https://docs.rs/rayon">rayon</a> library for CPU-bound |
| tasks. It is also possible to create an extra Tokio runtime dedicated to |
| CPU-bound tasks, but if you do this, you should be careful that the extra |
| runtime runs <em>only</em> CPU-bound tasks, as IO-bound tasks on that runtime |
| will behave poorly.</p> |
| <p>Hint: If using rayon, you can use a <a href="sync/oneshot/index.html"><code>oneshot</code></a> channel to send the result back |
| to Tokio when the rayon task finishes.</p> |
| <h3 id="asynchronous-io"><a href="#asynchronous-io">Asynchronous IO</a></h3> |
| <p>As well as scheduling and running tasks, Tokio provides everything you need |
| to perform input and output asynchronously.</p> |
| <p>The <a href="io/index.html"><code>tokio::io</code></a> module provides Tokio’s asynchronous core I/O primitives, |
| the <a href="io/trait.AsyncRead.html"><code>AsyncRead</code></a>, <a href="io/trait.AsyncWrite.html"><code>AsyncWrite</code></a>, and <a href="io/trait.AsyncBufRead.html"><code>AsyncBufRead</code></a> traits. In addition, |
| when the “io-util” feature flag is enabled, it also provides combinators and |
| functions for working with these traits, forming as an asynchronous |
| counterpart to <a href="std::io"><code>std::io</code></a>.</p> |
| <p>Tokio also includes APIs for performing various kinds of I/O and interacting |
| with the operating system asynchronously. These include:</p> |
| <ul> |
| <li><a href="net/index.html"><code>tokio::net</code></a>, which contains non-blocking versions of <a href="net/tcp/index.html">TCP</a>, <a href="net/struct.UdpSocket.html">UDP</a>, and |
| <a href="net/unix/index.html">Unix Domain Sockets</a> (enabled by the “net” feature flag),</li> |
| <li><a href="crate::fs"><code>tokio::fs</code></a>, similar to <a href="std::fs"><code>std::fs</code></a> but for performing filesystem I/O |
| asynchronously (enabled by the “fs” feature flag),</li> |
| <li><a href="crate::signal"><code>tokio::signal</code></a>, for asynchronously handling Unix and Windows OS signals |
| (enabled by the “signal” feature flag),</li> |
| <li><a href="crate::process"><code>tokio::process</code></a>, for spawning and managing child processes (enabled by |
| the “process” feature flag).</li> |
| </ul> |
| <h2 id="examples"><a href="#examples">Examples</a></h2> |
| <p>A simple TCP echo server:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::net::TcpListener; |
| <span class="kw">use </span>tokio::io::{AsyncReadExt, AsyncWriteExt}; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() -> <span class="prelude-ty">Result</span><(), Box<<span class="kw">dyn </span>std::error::Error>> { |
| <span class="kw">let </span>listener = TcpListener::bind(<span class="string">"127.0.0.1:8080"</span>).<span class="kw">await</span><span class="question-mark">?</span>; |
| |
| <span class="kw">loop </span>{ |
| <span class="kw">let </span>(<span class="kw-2">mut </span>socket, <span class="kw">_</span>) = listener.accept().<span class="kw">await</span><span class="question-mark">?</span>; |
| |
| tokio::spawn(<span class="kw">async move </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0</span>; <span class="number">1024</span>]; |
| |
| <span class="comment">// In a loop, read data from the socket and write the data back. |
| </span><span class="kw">loop </span>{ |
| <span class="kw">let </span>n = <span class="kw">match </span>socket.read(<span class="kw-2">&mut </span>buf).<span class="kw">await </span>{ |
| <span class="comment">// socket closed |
| </span><span class="prelude-val">Ok</span>(n) <span class="kw">if </span>n == <span class="number">0 </span>=> <span class="kw">return</span>, |
| <span class="prelude-val">Ok</span>(n) => n, |
| <span class="prelude-val">Err</span>(e) => { |
| <span class="macro">eprintln!</span>(<span class="string">"failed to read from socket; err = {:?}"</span>, e); |
| <span class="kw">return</span>; |
| } |
| }; |
| |
| <span class="comment">// Write the data back |
| </span><span class="kw">if let </span><span class="prelude-val">Err</span>(e) = socket.write_all(<span class="kw-2">&</span>buf[<span class="number">0</span>..n]).<span class="kw">await </span>{ |
| <span class="macro">eprintln!</span>(<span class="string">"failed to write to socket; err = {:?}"</span>, e); |
| <span class="kw">return</span>; |
| } |
| } |
| }); |
| } |
| }</code></pre></div> |
| <h3 id="feature-flags"><a href="#feature-flags">Feature flags</a></h3> |
| <p>Tokio uses a set of <a href="https://doc.rust-lang.org/cargo/reference/manifest.html#the-features-section">feature flags</a> to reduce the amount of compiled code. It |
| is possible to just enable certain features over others. By default, Tokio |
| does not enable any features but allows one to enable a subset for their use |
| case. Below is a list of the available feature flags. You may also notice |
| above each function, struct and trait there is listed one or more feature flags |
| that are required for that item to be used. If you are new to Tokio it is |
| recommended that you use the <code>full</code> feature flag which will enable all public APIs. |
| Beware though that this will pull in many extra dependencies that you may not |
| need.</p> |
| <ul> |
| <li><code>full</code>: Enables all features listed below except <code>test-util</code> and <code>tracing</code>.</li> |
| <li><code>rt</code>: Enables <code>tokio::spawn</code>, the current-thread scheduler, |
| and non-scheduler utilities.</li> |
| <li><code>rt-multi-thread</code>: Enables the heavier, multi-threaded, work-stealing scheduler.</li> |
| <li><code>io-util</code>: Enables the IO based <code>Ext</code> traits.</li> |
| <li><code>io-std</code>: Enable <code>Stdout</code>, <code>Stdin</code> and <code>Stderr</code> types.</li> |
| <li><code>net</code>: Enables <code>tokio::net</code> types such as <code>TcpStream</code>, <code>UnixStream</code> and |
| <code>UdpSocket</code>, as well as (on Unix-like systems) <code>AsyncFd</code> and (on |
| FreeBSD) <code>PollAio</code>.</li> |
| <li><code>time</code>: Enables <code>tokio::time</code> types and allows the schedulers to enable |
| the built in timer.</li> |
| <li><code>process</code>: Enables <code>tokio::process</code> types.</li> |
| <li><code>macros</code>: Enables <code>#[tokio::main]</code> and <code>#[tokio::test]</code> macros.</li> |
| <li><code>sync</code>: Enables all <code>tokio::sync</code> types.</li> |
| <li><code>signal</code>: Enables all <code>tokio::signal</code> types.</li> |
| <li><code>fs</code>: Enables <code>tokio::fs</code> types.</li> |
| <li><code>test-util</code>: Enables testing based infrastructure for the Tokio runtime.</li> |
| <li><code>parking_lot</code>: As a potential optimization, use the <em>parking_lot</em> crate’s |
| synchronization primitives internally. Also, this |
| dependency is necessary to construct some of our primitives |
| in a const context. MSRV may increase according to the |
| <em>parking_lot</em> release in use.</li> |
| </ul> |
| <p><em>Note: <code>AsyncRead</code> and <code>AsyncWrite</code> traits do not require any features and are |
| always available.</em></p> |
| <h4 id="unstable-features"><a href="#unstable-features">Unstable features</a></h4> |
| <p>Some feature flags are only available when specifying the <code>tokio_unstable</code> flag:</p> |
| <ul> |
| <li><code>tracing</code>: Enables tracing events.</li> |
| </ul> |
| <p>Likewise, some parts of the API are only available with the same flag:</p> |
| <ul> |
| <li>[<code>task::Builder</code>]</li> |
| <li>Some methods on <a href="task/struct.JoinSet.html" title="task::JoinSet"><code>task::JoinSet</code></a></li> |
| <li>[<code>runtime::RuntimeMetrics</code>]</li> |
| <li>[<code>runtime::Builder::unhandled_panic</code>]</li> |
| <li>[<code>task::Id</code>]</li> |
| </ul> |
| <p>This flag enables <strong>unstable</strong> features. The public API of these features |
| may break in 1.x releases. To enable these features, the <code>--cfg tokio_unstable</code> argument must be passed to <code>rustc</code> when compiling. This |
| serves to explicitly opt-in to features which may break semver conventions, |
| since Cargo <a href="https://internals.rust-lang.org/t/feature-request-unstable-opt-in-non-transitive-crate-features/16193#why-not-a-crate-feature-2">does not yet directly support such opt-ins</a>.</p> |
| <p>You can specify it in your project’s <code>.cargo/config.toml</code> file:</p> |
| <div class="example-wrap"><pre class="language-toml"><code>[build] |
| rustflags = ["--cfg", "tokio_unstable"]</code></pre></div> |
| <p>Alternatively, you can specify it with an environment variable:</p> |
| <div class="example-wrap"><pre class="language-sh"><code># Many *nix shells: |
| export RUSTFLAGS="--cfg tokio_unstable" |
| cargo build</code></pre></div><div class="example-wrap"><pre class="language-powershell"><code># Windows PowerShell: |
| $Env:RUSTFLAGS="--cfg tokio_unstable" |
| cargo build</code></pre></div><h3 id="wasm-support"><a href="#wasm-support">WASM support</a></h3> |
| <p>Tokio has some limited support for the WASM platform. Without the |
| <code>tokio_unstable</code> flag, the following features are supported:</p> |
| <ul> |
| <li><code>sync</code></li> |
| <li><code>macros</code></li> |
| <li><code>io-util</code></li> |
| <li><code>rt</code></li> |
| <li><code>time</code></li> |
| </ul> |
| <p>Enabling any other feature (including <code>full</code>) will cause a compilation |
| failure.</p> |
| <p>The <code>time</code> module will only work on WASM platforms that have support for |
| timers (e.g. wasm32-wasi). The timing functions will panic if used on a WASM |
| platform that does not support timers.</p> |
| <p>Note also that if the runtime becomes indefinitely idle, it will panic |
| immediately instead of blocking forever. On platforms that don’t support |
| time, this means that the runtime can never be idle in any way.</p> |
| <h4 id="unstable-wasm-support"><a href="#unstable-wasm-support">Unstable WASM support</a></h4> |
| <p>Tokio also has unstable support for some additional WASM features. This |
| requires the use of the <code>tokio_unstable</code> flag.</p> |
| <p>Using this flag enables the use of <code>tokio::net</code> on the wasm32-wasi target. |
| However, not all methods are available on the networking types as WASI |
| currently does not support the creation of new sockets from within WASM. |
| Because of this, sockets must currently be created via the <code>FromRawFd</code> |
| trait.</p> |
| </div></details><h2 id="modules" class="small-section-header"><a href="#modules">Modules</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="mod" href="io/index.html" title="tokio::io mod">io</a></div><div class="item-right docblock-short">Traits, helpers, and type definitions for asynchronous I/O functionality.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="net/index.html" title="tokio::net mod">net</a></div><div class="item-right docblock-short">TCP/UDP/Unix bindings for <code>tokio</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="runtime/index.html" title="tokio::runtime mod">runtime</a></div><div class="item-right docblock-short">The Tokio runtime.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="stream/index.html" title="tokio::stream mod">stream</a></div><div class="item-right docblock-short">Due to the <code>Stream</code> trait’s inclusion in <code>std</code> landing later than Tokio’s 1.0 |
| release, most of the Tokio stream utilities have been moved into the <a href="https://docs.rs/tokio-stream"><code>tokio-stream</code></a> |
| crate.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="sync/index.html" title="tokio::sync mod">sync</a></div><div class="item-right docblock-short">Synchronization primitives for use in asynchronous contexts.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="task/index.html" title="tokio::task mod">task</a></div><div class="item-right docblock-short">Asynchronous green-threads.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="time/index.html" title="tokio::time mod">time</a></div><div class="item-right docblock-short">Utilities for tracking time.</div></div></div><h2 id="macros" class="small-section-header"><a href="#macros">Macros</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.join.html" title="tokio::join macro">join</a></div><div class="item-right docblock-short">Waits on multiple concurrent branches, returning when <strong>all</strong> branches |
| complete.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.pin.html" title="tokio::pin macro">pin</a></div><div class="item-right docblock-short">Pins a value on the stack.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.select.html" title="tokio::select macro">select</a></div><div class="item-right docblock-short">Waits on multiple concurrent branches, returning when the <strong>first</strong> branch |
| completes, cancelling the remaining branches.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.task_local.html" title="tokio::task_local macro">task_local</a></div><div class="item-right docblock-short">Declares a new task-local key of type <a href="task/struct.LocalKey.html"><code>tokio::task::LocalKey</code></a>.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.try_join.html" title="tokio::try_join macro">try_join</a></div><div class="item-right docblock-short">Waits on multiple concurrent branches, returning when <strong>all</strong> branches |
| complete with <code>Ok(_)</code> or on the first <code>Err(_)</code>.</div></div></div><h2 id="functions" class="small-section-header"><a href="#functions">Functions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.spawn.html" title="tokio::spawn fn">spawn</a></div><div class="item-right docblock-short">Spawns a new asynchronous task, returning a |
| <a href="task/struct.JoinHandle.html"><code>JoinHandle</code></a> for it.</div></div></div><h2 id="attributes" class="small-section-header"><a href="#attributes">Attribute Macros</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="attr" href="attr.main.html" title="tokio::main attr">main</a></div><div class="item-right docblock-short">Marks async function to be executed by the selected runtime. This macro |
| helps set up a <code>Runtime</code> without requiring the user to use |
| <a href="../tokio/runtime/struct.Runtime.html">Runtime</a> or |
| <a href="../tokio/runtime/struct.Builder.html">Builder</a> directly.</div></div><div class="item-row"><div class="item-left module-item"><a class="attr" href="attr.test.html" title="tokio::test attr">test</a></div><div class="item-right docblock-short">Marks async function to be executed by runtime, suitable to test environment. |
| This macro helps set up a <code>Runtime</code> without requiring the user to use |
| <a href="../tokio/runtime/struct.Runtime.html">Runtime</a> or |
| <a href="../tokio/runtime/struct.Builder.html">Builder</a> directly.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../" data-current-crate="tokio" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
