| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/hyper-0.14.26/src/common/sync_wrapper.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>sync_wrapper.rs - source</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="../../../source-script.js"></script><script defer src="../../../source-files.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 source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../hyper/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../hyper/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><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="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="comment">/* |
| * This is a copy of the sync_wrapper crate. |
| */ |
| |
| </span><span class="doccomment">/// A mutual exclusion primitive that relies on static type information only |
| /// |
| /// In some cases synchronization can be proven statically: whenever you hold an exclusive `&mut` |
| /// reference, the Rust type system ensures that no other part of the program can hold another |
| /// reference to the data. Therefore it is safe to access it even if the current thread obtained |
| /// this reference via a channel. Whenever this is the case, the overhead of allocating and locking |
| /// a [`Mutex`] can be avoided by using this static version. |
| /// |
| /// One example where this is often applicable is [`Future`], which requires an exclusive reference |
| /// for its [`poll`] method: While a given `Future` implementation may not be safe to access by |
| /// multiple threads concurrently, the executor can only run the `Future` on one thread at any |
| /// given time, making it [`Sync`] in practice as long as the implementation is `Send`. You can |
| /// therefore use the sync wrapper to prove that your data structure is `Sync` even though it |
| /// contains such a `Future`. |
| /// |
| /// # Example |
| /// |
| /// ```ignore |
| /// use hyper::common::sync_wrapper::SyncWrapper; |
| /// use std::future::Future; |
| /// |
| /// struct MyThing { |
| /// future: SyncWrapper<Box<dyn Future<Output = String> + Send>>, |
| /// } |
| /// |
| /// impl MyThing { |
| /// // all accesses to `self.future` now require an exclusive reference or ownership |
| /// } |
| /// |
| /// fn assert_sync<T: Sync>() {} |
| /// |
| /// assert_sync::<MyThing>(); |
| /// ``` |
| /// |
| /// [`Mutex`]: https://doc.rust-lang.org/std/sync/struct.Mutex.html |
| /// [`Future`]: https://doc.rust-lang.org/std/future/trait.Future.html |
| /// [`poll`]: https://doc.rust-lang.org/std/future/trait.Future.html#method.poll |
| /// [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html |
| </span><span class="attribute">#[repr(transparent)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>SyncWrapper<T>(T); |
| |
| <span class="kw">impl</span><T> SyncWrapper<T> { |
| <span class="doccomment">/// Creates a new SyncWrapper containing the given value. |
| /// |
| /// # Examples |
| /// |
| /// ```ignore |
| /// use hyper::common::sync_wrapper::SyncWrapper; |
| /// |
| /// let wrapped = SyncWrapper::new(42); |
| /// ``` |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>new(value: T) -> <span class="self">Self </span>{ |
| <span class="self">Self</span>(value) |
| } |
| |
| <span class="doccomment">/// Acquires a reference to the protected value. |
| /// |
| /// This is safe because it requires an exclusive reference to the wrapper. Therefore this method |
| /// neither panics nor does it return an error. This is in contrast to [`Mutex::get_mut`] which |
| /// returns an error if another thread panicked while holding the lock. It is not recommended |
| /// to send an exclusive reference to a potentially damaged value to another thread for further |
| /// processing. |
| /// |
| /// [`Mutex::get_mut`]: https://doc.rust-lang.org/std/sync/struct.Mutex.html#method.get_mut |
| /// |
| /// # Examples |
| /// |
| /// ```ignore |
| /// use hyper::common::sync_wrapper::SyncWrapper; |
| /// |
| /// let mut wrapped = SyncWrapper::new(42); |
| /// let value = wrapped.get_mut(); |
| /// *value = 0; |
| /// assert_eq!(*wrapped.get_mut(), 0); |
| /// ``` |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>get_mut(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&mut </span>T { |
| <span class="kw-2">&mut </span><span class="self">self</span>.<span class="number">0 |
| </span>} |
| |
| <span class="doccomment">/// Consumes this wrapper, returning the underlying data. |
| /// |
| /// This is safe because it requires ownership of the wrapper, aherefore this method will neither |
| /// panic nor does it return an error. This is in contrast to [`Mutex::into_inner`] which |
| /// returns an error if another thread panicked while holding the lock. It is not recommended |
| /// to send an exclusive reference to a potentially damaged value to another thread for further |
| /// processing. |
| /// |
| /// [`Mutex::into_inner`]: https://doc.rust-lang.org/std/sync/struct.Mutex.html#method.into_inner |
| /// |
| /// # Examples |
| /// |
| /// ```ignore |
| /// use hyper::common::sync_wrapper::SyncWrapper; |
| /// |
| /// let mut wrapped = SyncWrapper::new(42); |
| /// assert_eq!(wrapped.into_inner(), 42); |
| /// ``` |
| </span><span class="attribute">#[allow(dead_code)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>into_inner(<span class="self">self</span>) -> T { |
| <span class="self">self</span>.<span class="number">0 |
| </span>} |
| } |
| |
| <span class="comment">// this is safe because the only operations permitted on this data structure require exclusive |
| // access or ownership |
| </span><span class="kw">unsafe impl</span><T: Send> Sync <span class="kw">for </span>SyncWrapper<T> {} |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="hyper" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
