204 lines
15 KiB
HTML
204 lines
15 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="API documentation for the Rust `Task` struct in crate `futures`.">
|
|||
|
|
<meta name="keywords" content="rust, rustlang, rust-lang, Task">
|
|||
|
|
|
|||
|
|
<title>futures::task::Task - 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>
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
</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>
|
|||
|
|
|
|||
|
|
<p class='location'>Struct Task</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#methods">Methods</a><div class="sidebar-links"><a href="#method.notify">notify</a><a href="#method.is_current">is_current</a><a href="#method.will_notify_current">will_notify_current</a></div><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Clone">Clone</a><a href="#impl-Debug">Debug</a></div></div><p class='location'><a href='../index.html'>futures</a>::<wbr><a href='index.html'>task</a></p><script>window.sidebarCurrent = {name: 'Task', 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'>futures</a>::<wbr><a href='index.html'>task</a>::<wbr><a class="struct" href=''>Task</a></span><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'>−</span>]
|
|||
|
|
</a>
|
|||
|
|
</span><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#58-62' title='goto source code'>[src]</a></span></h1>
|
|||
|
|
<pre class='rust struct'>pub struct Task { /* fields omitted */ }</pre><div class='docblock'><p>A handle to a "task", which represents a single lightweight "thread" of
|
|||
|
|
execution driving a future to completion.</p>
|
|||
|
|
<p>In general, futures are composed into large units of work, which are then
|
|||
|
|
spawned as tasks onto an <em>executor</em>. The executor is responsible for polling
|
|||
|
|
the future as notifications arrive, until the future terminates.</p>
|
|||
|
|
<p>This is obtained by the <code>task::current</code> function.</p>
|
|||
|
|
</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="../../futures/task/struct.Task.html" title="struct futures::task::Task">Task</a></code><a href='#impl' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#108-194' title='goto source code'>[src]</a></span></h3>
|
|||
|
|
<div class='impl-items'><h4 id='method.notify' class="method"><span id='notify.v' class='invisible'><code>pub fn <a href='#method.notify' class='fnname'>notify</a>(&self)</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#117-120' title='goto source code'>[src]</a></span></h4>
|
|||
|
|
<div class='docblock'><p>Indicate that the task should attempt to poll its future in a timely
|
|||
|
|
fashion.</p>
|
|||
|
|
<p>It's typically guaranteed that, after calling <code>notify</code>, <code>poll</code> will
|
|||
|
|
be called at least once subsequently (unless the future has terminated).
|
|||
|
|
If the task is currently polling its future when <code>notify</code> is called, it
|
|||
|
|
must poll the future <em>again</em> afterwards, ensuring that all relevant
|
|||
|
|
events are eventually observed by the future.</p>
|
|||
|
|
</div><h4 id='method.is_current' class="method"><span id='is_current.v' class='invisible'><code>pub fn <a href='#method.is_current' class='fnname'>is_current</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#165-167' title='goto source code'>[src]</a></span></h4>
|
|||
|
|
<div class='stability'><div class='stab deprecated'>Deprecated<p>: intended to be removed, see docs for details</p>
|
|||
|
|
</div></div><div class='docblock'><p>Returns <code>true</code> when called from within the context of the task.</p>
|
|||
|
|
<p>In other words, the task is currently running on the thread calling the
|
|||
|
|
function. Note that this is currently, and has historically, been
|
|||
|
|
implemented by tracking an <code>id</code> on every instance of <code>Spawn</code> created.
|
|||
|
|
When a <code>Spawn</code> is being polled it stores in thread-local-storage the id
|
|||
|
|
of the instance, and then <code>task::current</code> will return a <code>Task</code> that also
|
|||
|
|
stores this id.</p>
|
|||
|
|
<p>The intention of this function was to answer questions like "if I
|
|||
|
|
<code>notify</code> this task, is it equivalent to <code>task::current().notify()</code>?"
|
|||
|
|
The answer "yes" may be able to avoid some extra work to block the
|
|||
|
|
current task, such as sending a task along a channel or updating a
|
|||
|
|
stored <code>Task</code> somewhere. An answer of "no" typically results in doing
|
|||
|
|
the work anyway.</p>
|
|||
|
|
<p>Unfortunately this function has been somewhat buggy in the past and is
|
|||
|
|
not intended to be supported in the future. By simply matching <code>id</code> the
|
|||
|
|
intended question above isn't accurately taking into account, for
|
|||
|
|
example, unpark events (now deprecated, but still a feature). Thus many
|
|||
|
|
old users of this API weren't fully accounting for the question it was
|
|||
|
|
intended they were asking.</p>
|
|||
|
|
<p>This API continues to be implemented but will in the future, e.g. in the
|
|||
|
|
0.1.x series of this crate, eventually return <code>false</code> unconditionally.
|
|||
|
|
It is intended that this function will be removed in the next breaking
|
|||
|
|
change of this crate. If you'd like to continue to be able to answer the
|
|||
|
|
example question above, it's recommended you use the
|
|||
|
|
<code>will_notify_current</code> method.</p>
|
|||
|
|
<p>If you've got questions about this though please let us know! We'd like
|
|||
|
|
to learn about other use cases here that we did not consider.</p>
|
|||
|
|
<h1 id="panics" class="section-header"><a href="#panics">Panics</a></h1>
|
|||
|
|
<p>This function will panic if no current future is being polled.</p>
|
|||
|
|
</div><h4 id='method.will_notify_current' class="method"><span id='will_notify_current.v' class='invisible'><code>pub fn <a href='#method.will_notify_current' class='fnname'>will_notify_current</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#188-193' title='goto source code'>[src]</a></span></h4>
|
|||
|
|
<div class='docblock'><p>This function is intended as a performance optimization for structures
|
|||
|
|
which store a <code>Task</code> internally.</p>
|
|||
|
|
<p>The purpose of this function is to answer the question "if I <code>notify</code>
|
|||
|
|
this task is it equivalent to <code>task::current().notify()</code>". An answer
|
|||
|
|
"yes" may mean that you don't actually need to call <code>task::current()</code>
|
|||
|
|
and store it, but rather you can simply leave a stored task in place. An
|
|||
|
|
answer of "no" typically means that you need to call <code>task::current()</code>
|
|||
|
|
and store it somewhere.</p>
|
|||
|
|
<p>As this is purely a performance optimization a valid implementation for
|
|||
|
|
this function is to always return <code>false</code>. A best effort is done to
|
|||
|
|
return <code>true</code> where possible, but false negatives may happen. Note that
|
|||
|
|
this function will not return a false positive, however.</p>
|
|||
|
|
<h1 id="panics-1" class="section-header"><a href="#panics-1">Panics</a></h1>
|
|||
|
|
<p>This function will panic if no current future is being polled.</p>
|
|||
|
|
</div></div>
|
|||
|
|
<h2 id='implementations' class='small-section-header'>
|
|||
|
|
Trait Implementations<a href='#implementations' class='anchor'></a>
|
|||
|
|
</h2>
|
|||
|
|
<h3 id='impl-Clone' class='impl'><span class='in-band'><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a> for <a class="struct" href="../../futures/task/struct.Task.html" title="struct futures::task::Task">Task</a></code><a href='#impl-Clone' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#57' title='goto source code'>[src]</a></span></h3>
|
|||
|
|
<div class='impl-items'><h4 id='method.clone' class="method"><span id='clone.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#tymethod.clone' class='fnname'>clone</a>(&self) -> <a class="struct" href="../../futures/task/struct.Task.html" title="struct futures::task::Task">Task</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#57' title='goto source code'>[src]</a></span></h4>
|
|||
|
|
<div class='docblock'><p>Returns a copy of the value. <a href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#tymethod.clone">Read more</a></p>
|
|||
|
|
</div><h4 id='method.clone_from' class="method"><span id='clone_from.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#method.clone_from' class='fnname'>clone_from</a>(&mut self, source: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>Self)</code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.0.0'>1.0.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/clone.rs.html#112-114' title='goto source code'>[src]</a></span></h4>
|
|||
|
|
<div class='docblock'><p>Performs copy-assignment from <code>source</code>. <a href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#method.clone_from">Read more</a></p>
|
|||
|
|
</div></div><h3 id='impl-Debug' class='impl'><span class='in-band'><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="../../futures/task/struct.Task.html" title="struct futures::task::Task">Task</a></code><a href='#impl-Debug' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#196-201' 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='https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html#tymethod.fmt' class='fnname'>fmt</a>(&self, f: &mut <a class="struct" href="https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>) -> <a class="type" href="https://doc.rust-lang.org/nightly/core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/futures/task_impl/mod.rs.html#197-200' title='goto source code'>[src]</a></span></h4>
|
|||
|
|
<div class='docblock'><p>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/nightly/core/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 = "futures";
|
|||
|
|
</script>
|
|||
|
|
<script src="../../main.js"></script>
|
|||
|
|
<script defer src="../../search-index.js"></script>
|
|||
|
|
</body>
|
|||
|
|
</html>
|