mentat/crossbeam_epoch/struct.Guard.html
2018-08-22 17:04:13 +00:00

357 lines
No EOL
32 KiB
HTML
Raw 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 `Guard` struct in crate `crossbeam_epoch`.">
<meta name="keywords" content="rust, rustlang, rust-lang, Guard">
<title>crossbeam_epoch::Guard - 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">&#9776;</div>
<p class='location'>Struct Guard</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#methods">Methods</a><div class="sidebar-links"><a href="#method.defer">defer</a><a href="#method.flush">flush</a><a href="#method.repin">repin</a><a href="#method.repin_after">repin_after</a><a href="#method.collector">collector</a></div><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Drop">Drop</a><a href="#impl-Clone">Clone</a><a href="#impl-Debug">Debug</a></div></div><p class='location'><a href='index.html'>crossbeam_epoch</a></p><script>window.sidebarCurrent = {name: 'Guard', 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'>crossbeam_epoch</a>::<wbr><a class="struct" href=''>Guard</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'>&#x2212;</span>]
</a>
</span><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#77-79' title='goto source code'>[src]</a></span></h1>
<pre class='rust struct'>pub struct Guard { /* fields omitted */ }</pre><div class='docblock'><p>A guard that keeps the current thread pinned.</p>
<h1 id="pinning" class="section-header"><a href="#pinning">Pinning</a></h1>
<p>The current thread is pinned by calling <a href="fn.pin.html"><code>pin</code></a>, which returns a new guard:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">crossbeam_epoch</span> <span class="kw">as</span> <span class="ident">epoch</span>;
<span class="comment">// It is often convenient to prefix a call to `pin` with a `&amp;` in order to create a reference.</span>
<span class="comment">// This is not really necessary, but makes passing references to the guard a bit easier.</span>
<span class="kw">let</span> <span class="ident">guard</span> <span class="op">=</span> <span class="kw-2">&amp;</span><span class="ident">epoch</span>::<span class="ident">pin</span>();</pre>
<p>When a guard gets dropped, the current thread is automatically unpinned.</p>
<h1 id="pointers-on-the-stack" class="section-header"><a href="#pointers-on-the-stack">Pointers on the stack</a></h1>
<p>Having a guard allows us to create pointers on the stack to heap-allocated objects.
For example:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">crossbeam_epoch</span>::{<span class="self">self</span> <span class="kw">as</span> <span class="ident">epoch</span>, <span class="ident">Atomic</span>, <span class="ident">Owned</span>};
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">sync</span>::<span class="ident">atomic</span>::<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>;
<span class="comment">// Create a heap-allocated number.</span>
<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">Atomic</span>::<span class="ident">new</span>(<span class="number">777</span>);
<span class="comment">// Pin the current thread.</span>
<span class="kw">let</span> <span class="ident">guard</span> <span class="op">=</span> <span class="kw-2">&amp;</span><span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="comment">// Load the heap-allocated object and create pointer `p` on the stack.</span>
<span class="kw">let</span> <span class="ident">p</span> <span class="op">=</span> <span class="ident">a</span>.<span class="ident">load</span>(<span class="ident">SeqCst</span>, <span class="ident">guard</span>);
<span class="comment">// Dereference the pointer and print the value:</span>
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">num</span>) <span class="op">=</span> <span class="kw">unsafe</span> { <span class="ident">p</span>.<span class="ident">as_ref</span>() } {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;The number is {}.&quot;</span>, <span class="ident">num</span>);
}</pre>
<h1 id="multiple-guards" class="section-header"><a href="#multiple-guards">Multiple guards</a></h1>
<p>Pinning is reentrant and it is perfectly legal to create multiple guards. In that case, the
thread will actually be pinned only when the first guard is created and unpinned when the last
one is dropped:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">crossbeam_epoch</span> <span class="kw">as</span> <span class="ident">epoch</span>;
<span class="kw">let</span> <span class="ident">guard1</span> <span class="op">=</span> <span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="kw">let</span> <span class="ident">guard2</span> <span class="op">=</span> <span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">epoch</span>::<span class="ident">is_pinned</span>());
<span class="ident">drop</span>(<span class="ident">guard1</span>);
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">epoch</span>::<span class="ident">is_pinned</span>());
<span class="ident">drop</span>(<span class="ident">guard2</span>);
<span class="macro">assert</span><span class="macro">!</span>(<span class="op">!</span><span class="ident">epoch</span>::<span class="ident">is_pinned</span>());</pre>
<p>The same can be achieved by cloning guards:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">crossbeam_epoch</span> <span class="kw">as</span> <span class="ident">epoch</span>;
<span class="kw">let</span> <span class="ident">guard1</span> <span class="op">=</span> <span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="kw">let</span> <span class="ident">guard2</span> <span class="op">=</span> <span class="ident">guard1</span>.<span class="ident">clone</span>();</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="../crossbeam_epoch/struct.Guard.html" title="struct crossbeam_epoch::Guard">Guard</a></code><a href='#impl' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#81-322' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.defer' class="method"><span id='defer.v' class='invisible'><code>pub unsafe fn <a href='#method.defer' class='fnname'>defer</a>&lt;F, R&gt;(&amp;self, f: 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>() -&gt; R,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#171-178' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Stores a function so that it can be executed at some point after all currently pinned
threads get unpinned.</p>
<p>This method first stores <code>f</code> into the thread-local (or handle-local) cache. If this cache
becomes full, some functions are moved into the global cache. At the same time, some
functions from both local and global caches may get executed in order to incrementally
clean up the caches as they fill up.</p>
<p>There is no guarantee when exactly <code>f</code> will be executed. The only guarantee is that won't
until all currently pinned threads get unpinned. In theory, <code>f</code> might never be deallocated,
but the epoch-based garbage collection will make an effort to execute it reasonably soon.</p>
<p>If this method is called from an <a href="fn.unprotected.html"><code>unprotected</code></a> guard, the function will simply be
executed immediately.</p>
<h1 id="safety" class="section-header"><a href="#safety">Safety</a></h1>
<p>The given function must not hold reference onto the stack. It is highly recommended that
the passed function is <strong>always</strong> marked with <code>move</code> in order to prevent accidental
borrows.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">crossbeam_epoch</span> <span class="kw">as</span> <span class="ident">epoch</span>;
<span class="kw">let</span> <span class="ident">guard</span> <span class="op">=</span> <span class="kw-2">&amp;</span><span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="kw">let</span> <span class="ident">message</span> <span class="op">=</span> <span class="string">&quot;Hello!&quot;</span>;
<span class="kw">unsafe</span> {
<span class="comment">// ALWAYS use `move` when sending a closure into `defef`.</span>
<span class="ident">guard</span>.<span class="ident">defer</span>(<span class="kw">move</span> <span class="op">||</span> {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;{}&quot;</span>, <span class="ident">message</span>);
});
}</pre>
<p>Apart from that, keep in mind that another thread may execute <code>f</code>, so anything accessed by
the closure must be <code>Send</code>.</p>
<p>We intentionally didn't require <code>F: Send</code>, because Rust's type systems usually cannot prove
<code>F: Send</code> for typical use cases. For example, consider the following code snippet, which
exemplifies the typical use case of deferring the deallocation of a shared reference:</p>
<div class='information'><div class='tooltip ignore'><span class='tooltiptext'>This example is not tested</span></div></div><pre class="rust rust-example-rendered ignore">
<span class="kw">let</span> <span class="ident">shared</span> <span class="op">=</span> <span class="ident">Owned</span>::<span class="ident">new</span>(<span class="number">7i32</span>).<span class="ident">into_shared</span>(<span class="ident">guard</span>);
<span class="ident">guard</span>.<span class="ident">defer</span>(<span class="ident">Deferred</span>::<span class="ident">new</span>(<span class="kw">move</span> <span class="op">||</span> <span class="ident">shared</span>.<span class="ident">into_owned</span>())); <span class="comment">// `Shared` is not `Send`!</span></pre>
<p>While <code>Shared</code> is not <code>Send</code>, it's safe for another thread to call the deferred function,
because it's called only after the grace period and <code>shared</code> is no longer shared with other
threads. But we don't expect type systems to prove this.</p>
<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
<p>When a heap-allocated object in a data structure becomes unreachable, it has to be
deallocated. However, the current thread and other threads may be still holding references
on the stack to that same object. Therefore it cannot be deallocated before those references
get dropped. This method can defer deallocation until all those threads get unpinned and
consequently drop all their references on the stack.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">crossbeam_epoch</span>::{<span class="self">self</span> <span class="kw">as</span> <span class="ident">epoch</span>, <span class="ident">Atomic</span>, <span class="ident">Owned</span>};
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">sync</span>::<span class="ident">atomic</span>::<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>;
<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">Atomic</span>::<span class="ident">new</span>(<span class="string">&quot;foo&quot;</span>);
<span class="comment">// Now suppose that `a` is shared among multiple threads and concurrently</span>
<span class="comment">// accessed and modified...</span>
<span class="comment">// Pin the current thread.</span>
<span class="kw">let</span> <span class="ident">guard</span> <span class="op">=</span> <span class="kw-2">&amp;</span><span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="comment">// Steal the object currently stored in `a` and swap it with another one.</span>
<span class="kw">let</span> <span class="ident">p</span> <span class="op">=</span> <span class="ident">a</span>.<span class="ident">swap</span>(<span class="ident">Owned</span>::<span class="ident">new</span>(<span class="string">&quot;bar&quot;</span>).<span class="ident">into_shared</span>(<span class="ident">guard</span>), <span class="ident">SeqCst</span>, <span class="ident">guard</span>);
<span class="kw">if</span> <span class="op">!</span><span class="ident">p</span>.<span class="ident">is_null</span>() {
<span class="comment">// The object `p` is pointing to is now unreachable.</span>
<span class="comment">// Defer its deallocation until all currently pinned threads get unpinned.</span>
<span class="kw">unsafe</span> {
<span class="comment">// ALWAYS use `move` when sending a closure into `defer`.</span>
<span class="ident">guard</span>.<span class="ident">defer</span>(<span class="kw">move</span> <span class="op">||</span> {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;{} is now being deallocated.&quot;</span>, <span class="ident">p</span>.<span class="ident">deref</span>());
<span class="comment">// Now we have unique access to the object pointed to by `p` and can turn it</span>
<span class="comment">// into an `Owned`. Dropping the `Owned` will deallocate the object.</span>
<span class="ident">drop</span>(<span class="ident">p</span>.<span class="ident">into_owned</span>());
});
}
}</pre>
</div><h4 id='method.flush' class="method"><span id='flush.v' class='invisible'><code>pub fn <a href='#method.flush' class='fnname'>flush</a>(&amp;self)</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#204-208' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Clears up the thread-local cache of deferred functions by executing them or moving into the
global cache.</p>
<p>Call this method after deferring execution of a function if you want to get it executed as
soon as possible. Flushing will make sure it is residing in in the global cache, so that
any thread has a chance of taking the function and executing it.</p>
<p>If this method is called from an <a href="fn.unprotected.html"><code>unprotected</code></a> guard, it is a no-op (nothing happens).</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">crossbeam_epoch</span> <span class="kw">as</span> <span class="ident">epoch</span>;
<span class="kw">let</span> <span class="ident">guard</span> <span class="op">=</span> <span class="kw-2">&amp;</span><span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="kw">unsafe</span> {
<span class="ident">guard</span>.<span class="ident">defer</span>(<span class="kw">move</span> <span class="op">||</span> {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;This better be printed as soon as possible!&quot;</span>);
});
}
<span class="ident">guard</span>.<span class="ident">flush</span>();</pre>
</div><h4 id='method.repin' class="method"><span id='repin.v' class='invisible'><code>pub fn <a href='#method.repin' class='fnname'>repin</a>(&amp;mut self)</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#241-245' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Unpins and then immediately re-pins the thread.</p>
<p>This method is useful when you don't want delay the advancement of the global epoch by
holding an old epoch. For safety, you should not maintain any guard-based reference across
the call (the latter is enforced by <code>&amp;mut self</code>). The thread will only be repinned if this
is the only active guard for the current thread.</p>
<p>If this method is called from an <a href="fn.unprotected.html"><code>unprotected</code></a> guard, then the call will be just no-op.</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">crossbeam_epoch</span>::{<span class="self">self</span> <span class="kw">as</span> <span class="ident">epoch</span>, <span class="ident">Atomic</span>};
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">sync</span>::<span class="ident">atomic</span>::<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">time</span>::<span class="ident">Duration</span>;
<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">Atomic</span>::<span class="ident">new</span>(<span class="number">777</span>);
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">guard</span> <span class="op">=</span> <span class="ident">epoch</span>::<span class="ident">pin</span>();
{
<span class="kw">let</span> <span class="ident">p</span> <span class="op">=</span> <span class="ident">a</span>.<span class="ident">load</span>(<span class="ident">SeqCst</span>, <span class="kw-2">&amp;</span><span class="ident">guard</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="kw">unsafe</span> { <span class="ident">p</span>.<span class="ident">as_ref</span>() }, <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="number">777</span>));
}
<span class="ident">guard</span>.<span class="ident">repin</span>();
{
<span class="kw">let</span> <span class="ident">p</span> <span class="op">=</span> <span class="ident">a</span>.<span class="ident">load</span>(<span class="ident">SeqCst</span>, <span class="kw-2">&amp;</span><span class="ident">guard</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="kw">unsafe</span> { <span class="ident">p</span>.<span class="ident">as_ref</span>() }, <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="number">777</span>));
}</pre>
</div><h4 id='method.repin_after' class="method"><span id='repin_after.v' class='invisible'><code>pub fn <a href='#method.repin_after' class='fnname'>repin_after</a>&lt;F, R&gt;(&amp;mut self, f: F) -&gt; R <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>() -&gt; R,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#279-299' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Temporarily unpins the thread, executes the given function and then re-pins the thread.</p>
<p>This method is useful when you need to perform a long-running operation (e.g. sleeping)
and don't need to maintain any guard-based reference across the call (the latter is enforced
by <code>&amp;mut self</code>). The thread will only be unpinned if this is the only active guard for the
current thread.</p>
<p>If this method is called from an <a href="fn.unprotected.html"><code>unprotected</code></a> guard, then the passed function is called
directly without unpinning the thread.</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">crossbeam_epoch</span>::{<span class="self">self</span> <span class="kw">as</span> <span class="ident">epoch</span>, <span class="ident">Atomic</span>};
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">sync</span>::<span class="ident">atomic</span>::<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">time</span>::<span class="ident">Duration</span>;
<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">Atomic</span>::<span class="ident">new</span>(<span class="number">777</span>);
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">guard</span> <span class="op">=</span> <span class="ident">epoch</span>::<span class="ident">pin</span>();
{
<span class="kw">let</span> <span class="ident">p</span> <span class="op">=</span> <span class="ident">a</span>.<span class="ident">load</span>(<span class="ident">SeqCst</span>, <span class="kw-2">&amp;</span><span class="ident">guard</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="kw">unsafe</span> { <span class="ident">p</span>.<span class="ident">as_ref</span>() }, <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="number">777</span>));
}
<span class="ident">guard</span>.<span class="ident">repin_after</span>(<span class="op">||</span> <span class="ident">thread</span>::<span class="ident">sleep</span>(<span class="ident">Duration</span>::<span class="ident">from_millis</span>(<span class="number">50</span>)));
{
<span class="kw">let</span> <span class="ident">p</span> <span class="op">=</span> <span class="ident">a</span>.<span class="ident">load</span>(<span class="ident">SeqCst</span>, <span class="kw-2">&amp;</span><span class="ident">guard</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="kw">unsafe</span> { <span class="ident">p</span>.<span class="ident">as_ref</span>() }, <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="number">777</span>));
}</pre>
</div><h4 id='method.collector' class="method"><span id='collector.v' class='invisible'><code>pub fn <a href='#method.collector' class='fnname'>collector</a>(&amp;self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;&amp;<a class="struct" href="../crossbeam_epoch/struct.Collector.html" title="struct crossbeam_epoch::Collector">Collector</a>&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#319-321' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns the <code>Collector</code> associated with this guard.</p>
<p>This method is useful when you need to ensure that all guards used with
a data structure come from the same collector.</p>
<p>If this method is called from an <a href="fn.unprotected.html"><code>unprotected</code></a> guard, then <code>None</code> is returned.</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">crossbeam_epoch</span> <span class="kw">as</span> <span class="ident">epoch</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">guard1</span> <span class="op">=</span> <span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">guard2</span> <span class="op">=</span> <span class="ident">epoch</span>::<span class="ident">pin</span>();
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">guard1</span>.<span class="ident">collector</span>() <span class="op">==</span> <span class="ident">guard2</span>.<span class="ident">collector</span>());</pre>
</div></div>
<h2 id='implementations' class='small-section-header'>
Trait Implementations<a href='#implementations' class='anchor'></a>
</h2>
<h3 id='impl-Drop' class='impl'><span class='in-band'><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/drop/trait.Drop.html" title="trait core::ops::drop::Drop">Drop</a> for <a class="struct" href="../crossbeam_epoch/struct.Guard.html" title="struct crossbeam_epoch::Guard">Guard</a></code><a href='#impl-Drop' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#324-331' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.drop' class="method"><span id='drop.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/ops/drop/trait.Drop.html#tymethod.drop' class='fnname'>drop</a>(&amp;mut self)</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#326-330' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Executes the destructor for this type. <a href="https://doc.rust-lang.org/nightly/core/ops/drop/trait.Drop.html#tymethod.drop">Read more</a></p>
</div></div><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="../crossbeam_epoch/struct.Guard.html" title="struct crossbeam_epoch::Guard">Guard</a></code><a href='#impl-Clone' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#333-341' 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>(&amp;self) -&gt; <a class="struct" href="../crossbeam_epoch/struct.Guard.html" title="struct crossbeam_epoch::Guard">Guard</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#335-340' 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>(&amp;mut self, source: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;</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="../crossbeam_epoch/struct.Guard.html" title="struct crossbeam_epoch::Guard">Guard</a></code><a href='#impl-Debug' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/crossbeam_epoch/guard.rs.html#343-347' 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>(&amp;self, f: &amp;mut <a class="struct" href="https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>) -&gt; <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/crossbeam_epoch/guard.rs.html#344-346' 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>&#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>
</div>
</div>
</aside>
<script>
window.rootPath = "../";
window.currentCrate = "crossbeam_epoch";
</script>
<script src="../main.js"></script>
<script defer src="../search-index.js"></script>
</body>
</html>