| <!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="An asynchronous reader-writer lock."><meta name="keywords" content="rust, rustlang, rust-lang, RwLock"><title>RwLock in tokio::sync - 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" 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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="#">RwLock</a></h2><div class="sidebar-elems"><section><h3><a href="#implementations">Methods</a></h3><ul class="block"><li><a href="#method.blocking_read">blocking_read</a></li><li><a href="#method.blocking_write">blocking_write</a></li><li><a href="#method.get_mut">get_mut</a></li><li><a href="#method.into_inner">into_inner</a></li><li><a href="#method.new">new</a></li><li><a href="#method.read">read</a></li><li><a href="#method.read_owned">read_owned</a></li><li><a href="#method.try_read">try_read</a></li><li><a href="#method.try_read_owned">try_read_owned</a></li><li><a href="#method.try_write">try_write</a></li><li><a href="#method.try_write_owned">try_write_owned</a></li><li><a href="#method.with_max_readers">with_max_readers</a></li><li><a href="#method.write">write</a></li><li><a href="#method.write_owned">write_owned</a></li></ul><h3><a href="#trait-implementations">Trait Implementations</a></h3><ul class="block"><li><a href="#impl-Debug-for-RwLock%3CT%3E">Debug</a></li><li><a href="#impl-Default-for-RwLock%3CT%3E">Default</a></li><li><a href="#impl-From%3CT%3E-for-RwLock%3CT%3E">From<T></a></li><li><a href="#impl-Send-for-RwLock%3CT%3E">Send</a></li><li><a href="#impl-Sync-for-RwLock%3CT%3E">Sync</a></li></ul><h3><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><ul class="block"><li><a href="#impl-RefUnwindSafe-for-RwLock%3CT%3E">!RefUnwindSafe</a></li><li><a href="#impl-Unpin-for-RwLock%3CT%3E">Unpin</a></li><li><a href="#impl-UnwindSafe-for-RwLock%3CT%3E">UnwindSafe</a></li></ul><h3><a href="#blanket-implementations">Blanket Implementations</a></h3><ul class="block"><li><a href="#impl-Any-for-RwLock%3CT%3E">Any</a></li><li><a href="#impl-Borrow%3CT%3E-for-RwLock%3CT%3E">Borrow<T></a></li><li><a href="#impl-BorrowMut%3CT%3E-for-RwLock%3CT%3E">BorrowMut<T></a></li><li><a href="#impl-From%3C!%3E-for-RwLock%3CT%3E">From<!></a></li><li><a href="#impl-From%3CT%3E-for-RwLock%3CT%3E-1">From<T></a></li><li><a href="#impl-Into%3CU%3E-for-RwLock%3CT%3E">Into<U></a></li><li><a href="#impl-TryFrom%3CU%3E-for-RwLock%3CT%3E">TryFrom<U></a></li><li><a href="#impl-TryInto%3CU%3E-for-RwLock%3CT%3E">TryInto<U></a></li></ul></section><h2><a href="index.html">In tokio::sync</a></h2></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">Struct <a href="../index.html">tokio</a>::<wbr><a href="index.html">sync</a>::<wbr><a class="struct" href="#">RwLock</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/sync/rwlock.rs.html#88-100">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust struct"><code>pub struct RwLock<T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>> { /* private fields */ }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>An asynchronous reader-writer lock.</p> |
| <p>This type of lock allows a number of readers or at most one writer at any |
| point in time. The write portion of this lock typically allows modification |
| of the underlying data (exclusive access) and the read portion of this lock |
| typically allows for read-only access (shared access).</p> |
| <p>In comparison, a <a href="struct.Mutex.html"><code>Mutex</code></a> does not distinguish between readers or writers |
| that acquire the lock, therefore causing any tasks waiting for the lock to |
| become available to yield. An <code>RwLock</code> will allow any number of readers to |
| acquire the lock as long as a writer is not holding the lock.</p> |
| <p>The priority policy of Tokio’s read-write lock is <em>fair</em> (or |
| <a href="https://en.wikipedia.org/wiki/Readers%E2%80%93writer_lock#Priority_policies"><em>write-preferring</em></a>), in order to ensure that readers cannot starve |
| writers. Fairness is ensured using a first-in, first-out queue for the tasks |
| awaiting the lock; if a task that wishes to acquire the write lock is at the |
| head of the queue, read locks will not be given out until the write lock has |
| been released. This is in contrast to the Rust standard library’s |
| <code>std::sync::RwLock</code>, where the priority policy is dependent on the |
| operating system’s implementation.</p> |
| <p>The type parameter <code>T</code> represents the data that this lock protects. It is |
| required that <code>T</code> satisfies <a href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html"><code>Send</code></a> to be shared across threads. The RAII guards |
| returned from the locking methods implement <a href="https://doc.rust-lang.org/nightly/core/ops/deref/trait.Deref.html"><code>Deref</code></a> |
| (and <a href="https://doc.rust-lang.org/nightly/core/ops/deref/trait.DerefMut.html"><code>DerefMut</code></a> |
| for the <code>write</code> methods) to allow access to the content of the lock.</p> |
| <h2 id="examples"><a href="#examples">Examples</a></h2> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>lock = RwLock::new(<span class="number">5</span>); |
| |
| <span class="comment">// many reader locks can be held at once |
| </span>{ |
| <span class="kw">let </span>r1 = lock.read().<span class="kw">await</span>; |
| <span class="kw">let </span>r2 = lock.read().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>r1, <span class="number">5</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>r2, <span class="number">5</span>); |
| } <span class="comment">// read locks are dropped at this point |
| |
| // only one write lock may be held, however |
| </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>w = lock.write().<span class="kw">await</span>; |
| <span class="kw-2">*</span>w += <span class="number">1</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>w, <span class="number">6</span>); |
| } <span class="comment">// write lock is dropped here |
| </span>}</code></pre></div> |
| </div></details><h2 id="implementations" class="small-section-header">Implementations<a href="#implementations" class="anchor"></a></h2><div id="implementations-list"><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#193-1081">source</a><a href="#impl-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>> <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.new" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#204-253">source</a><h4 class="code-header">pub fn <a href="#method.new" class="fnname">new</a>(value: T) -> <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</span></h4></section></summary><div class="docblock"><p>Creates a new instance of an <code>RwLock<T></code> which is unlocked.</p> |
| <h5 id="examples-1"><a href="#examples-1">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="kw">let </span>lock = RwLock::new(<span class="number">5</span>);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.with_max_readers" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#270-326">source</a><h4 class="code-header">pub fn <a href="#method.with_max_readers" class="fnname">with_max_readers</a>(value: T, max_reads: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u32.html">u32</a>) -> <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</span></h4></section></summary><div class="docblock"><p>Creates a new instance of an <code>RwLock<T></code> which is unlocked |
| and allows a maximum of <code>max_reads</code> concurrent readers.</p> |
| <h5 id="examples-2"><a href="#examples-2">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="kw">let </span>lock = RwLock::with_max_readers(<span class="number">5</span>, <span class="number">1024</span>);</code></pre></div> |
| <h5 id="panics"><a href="#panics">Panics</a></h5> |
| <p>Panics if <code>max_reads</code> is more than <code>u32::MAX >> 3</code>.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.read" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#423-462">source</a><h4 class="code-header">pub async fn <a href="#method.read" class="fnname">read</a>(&self) -> <a class="struct" href="struct.RwLockReadGuard.html" title="struct tokio::sync::RwLockReadGuard">RwLockReadGuard</a><'_, T></h4></section></summary><div class="docblock"><p>Locks this <code>RwLock</code> with shared read access, causing the current task |
| to yield until the lock has been acquired.</p> |
| <p>The calling task will yield until there are no writers which hold the |
| lock. There may be other readers inside the lock when the task resumes.</p> |
| <p>Note that under the priority policy of <a href="struct.RwLock.html" title="RwLock"><code>RwLock</code></a>, read locks are not |
| granted until prior write locks, to prevent starvation. Therefore |
| deadlock may occur if a read lock is held by the current task, a write |
| lock attempt is made, and then a subsequent read lock attempt is made |
| by the current task.</p> |
| <p>Returns an RAII guard which will drop this read access of the <code>RwLock</code> |
| when dropped.</p> |
| <h5 id="cancel-safety"><a href="#cancel-safety">Cancel safety</a></h5> |
| <p>This method uses a queue to fairly distribute locks in the order they |
| were requested. Cancelling a call to <code>read</code> makes you lose your place in |
| the queue.</p> |
| <h5 id="examples-3"><a href="#examples-3">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>lock = Arc::new(RwLock::new(<span class="number">1</span>)); |
| <span class="kw">let </span>c_lock = lock.clone(); |
| |
| <span class="kw">let </span>n = lock.read().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>n, <span class="number">1</span>); |
| |
| tokio::spawn(<span class="kw">async move </span>{ |
| <span class="comment">// While main has an active read lock, we acquire one too. |
| </span><span class="kw">let </span>r = c_lock.read().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>r, <span class="number">1</span>); |
| }).<span class="kw">await</span>.expect(<span class="string">"The spawned task has panicked"</span>); |
| |
| <span class="comment">// Drop the guard after the spawned task finishes. |
| </span>drop(n); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.blocking_read" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#513-515">source</a><h4 class="code-header">pub fn <a href="#method.blocking_read" class="fnname">blocking_read</a>(&self) -> <a class="struct" href="struct.RwLockReadGuard.html" title="struct tokio::sync::RwLockReadGuard">RwLockReadGuard</a><'_, T></h4></section></summary><div class="docblock"><p>Blockingly locks this <code>RwLock</code> with shared read access.</p> |
| <p>This method is intended for use cases where you |
| need to use this rwlock in asynchronous code as well as in synchronous code.</p> |
| <p>Returns an RAII guard which will drop the read access of this <code>RwLock</code> when dropped.</p> |
| <h5 id="panics-1"><a href="#panics-1">Panics</a></h5> |
| <p>This function panics if called within an asynchronous execution context.</p> |
| <ul> |
| <li>If you find yourself in an asynchronous execution context and needing |
| to call some (synchronous) function which performs one of these |
| <code>blocking_</code> operations, then consider wrapping that call inside |
| <a href="../runtime/struct.Handle.html#method.spawn_blocking" title="crate::runtime::Handle::spawn_blocking"><code>spawn_blocking()</code></a> |
| (or [<code>block_in_place()</code>][crate::task::block_in_place]).</li> |
| </ul> |
| <h5 id="examples-4"><a href="#examples-4">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>rwlock = Arc::new(RwLock::new(<span class="number">1</span>)); |
| <span class="kw">let </span><span class="kw-2">mut </span>write_lock = rwlock.write().<span class="kw">await</span>; |
| |
| <span class="kw">let </span>blocking_task = tokio::task::spawn_blocking({ |
| <span class="kw">let </span>rwlock = Arc::clone(<span class="kw-2">&</span>rwlock); |
| <span class="kw">move </span>|| { |
| <span class="comment">// This shall block until the `write_lock` is released. |
| </span><span class="kw">let </span>read_lock = rwlock.blocking_read(); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>read_lock, <span class="number">0</span>); |
| } |
| }); |
| |
| <span class="kw-2">*</span>write_lock -= <span class="number">1</span>; |
| drop(write_lock); <span class="comment">// release the lock. |
| |
| // Await the completion of the blocking task. |
| </span>blocking_task.<span class="kw">await</span>.unwrap(); |
| |
| <span class="comment">// Assert uncontended. |
| </span><span class="macro">assert!</span>(rwlock.try_write().is_ok()); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.read_owned" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#568-610">source</a><h4 class="code-header">pub async fn <a href="#method.read_owned" class="fnname">read_owned</a>(self: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="struct alloc::sync::Arc">Arc</a><Self>) -> <a class="struct" href="struct.OwnedRwLockReadGuard.html" title="struct tokio::sync::OwnedRwLockReadGuard">OwnedRwLockReadGuard</a><T></h4></section></summary><div class="docblock"><p>Locks this <code>RwLock</code> with shared read access, causing the current task |
| to yield until the lock has been acquired.</p> |
| <p>The calling task will yield until there are no writers which hold the |
| lock. There may be other readers inside the lock when the task resumes.</p> |
| <p>This method is identical to <a href="struct.RwLock.html#method.read" title="RwLock::read"><code>RwLock::read</code></a>, except that the returned |
| guard references the <code>RwLock</code> with an <a href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="Arc"><code>Arc</code></a> rather than by borrowing |
| it. Therefore, the <code>RwLock</code> must be wrapped in an <code>Arc</code> to call this |
| method, and the guard will live for the <code>'static</code> lifetime, as it keeps |
| the <code>RwLock</code> alive by holding an <code>Arc</code>.</p> |
| <p>Note that under the priority policy of <a href="struct.RwLock.html" title="RwLock"><code>RwLock</code></a>, read locks are not |
| granted until prior write locks, to prevent starvation. Therefore |
| deadlock may occur if a read lock is held by the current task, a write |
| lock attempt is made, and then a subsequent read lock attempt is made |
| by the current task.</p> |
| <p>Returns an RAII guard which will drop this read access of the <code>RwLock</code> |
| when dropped.</p> |
| <h5 id="cancel-safety-1"><a href="#cancel-safety-1">Cancel safety</a></h5> |
| <p>This method uses a queue to fairly distribute locks in the order they |
| were requested. Cancelling a call to <code>read_owned</code> makes you lose your |
| place in the queue.</p> |
| <h5 id="examples-5"><a href="#examples-5">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>lock = Arc::new(RwLock::new(<span class="number">1</span>)); |
| <span class="kw">let </span>c_lock = lock.clone(); |
| |
| <span class="kw">let </span>n = lock.read_owned().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>n, <span class="number">1</span>); |
| |
| tokio::spawn(<span class="kw">async move </span>{ |
| <span class="comment">// While main has an active read lock, we acquire one too. |
| </span><span class="kw">let </span>r = c_lock.read_owned().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>r, <span class="number">1</span>); |
| }).<span class="kw">await</span>.expect(<span class="string">"The spawned task has panicked"</span>); |
| |
| <span class="comment">// Drop the guard after the spawned task finishes. |
| </span>drop(n); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_read" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#644-669">source</a><h4 class="code-header">pub fn <a href="#method.try_read" class="fnname">try_read</a>(&self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="struct" href="struct.RwLockReadGuard.html" title="struct tokio::sync::RwLockReadGuard">RwLockReadGuard</a><'_, T>, <a class="struct" href="struct.TryLockError.html" title="struct tokio::sync::TryLockError">TryLockError</a>></h4></section></summary><div class="docblock"><p>Attempts to acquire this <code>RwLock</code> with shared read access.</p> |
| <p>If the access couldn’t be acquired immediately, returns <a href="struct.TryLockError.html"><code>TryLockError</code></a>. |
| Otherwise, an RAII guard is returned which will release read access |
| when dropped.</p> |
| <h5 id="examples-6"><a href="#examples-6">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>lock = Arc::new(RwLock::new(<span class="number">1</span>)); |
| <span class="kw">let </span>c_lock = lock.clone(); |
| |
| <span class="kw">let </span>v = lock.try_read().unwrap(); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>v, <span class="number">1</span>); |
| |
| tokio::spawn(<span class="kw">async move </span>{ |
| <span class="comment">// While main has an active read lock, we acquire one too. |
| </span><span class="kw">let </span>n = c_lock.read().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>n, <span class="number">1</span>); |
| }).<span class="kw">await</span>.expect(<span class="string">"The spawned task has panicked"</span>); |
| |
| <span class="comment">// Drop the guard when spawned task finishes. |
| </span>drop(v); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_read_owned" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#709-734">source</a><h4 class="code-header">pub fn <a href="#method.try_read_owned" class="fnname">try_read_owned</a>(<br> self: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="struct alloc::sync::Arc">Arc</a><Self><br>) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="struct" href="struct.OwnedRwLockReadGuard.html" title="struct tokio::sync::OwnedRwLockReadGuard">OwnedRwLockReadGuard</a><T>, <a class="struct" href="struct.TryLockError.html" title="struct tokio::sync::TryLockError">TryLockError</a>></h4></section></summary><div class="docblock"><p>Attempts to acquire this <code>RwLock</code> with shared read access.</p> |
| <p>If the access couldn’t be acquired immediately, returns <a href="struct.TryLockError.html"><code>TryLockError</code></a>. |
| Otherwise, an RAII guard is returned which will release read access |
| when dropped.</p> |
| <p>This method is identical to <a href="struct.RwLock.html#method.try_read" title="RwLock::try_read"><code>RwLock::try_read</code></a>, except that the |
| returned guard references the <code>RwLock</code> with an <a href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="Arc"><code>Arc</code></a> rather than by |
| borrowing it. Therefore, the <code>RwLock</code> must be wrapped in an <code>Arc</code> to |
| call this method, and the guard will live for the <code>'static</code> lifetime, |
| as it keeps the <code>RwLock</code> alive by holding an <code>Arc</code>.</p> |
| <h5 id="examples-7"><a href="#examples-7">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>lock = Arc::new(RwLock::new(<span class="number">1</span>)); |
| <span class="kw">let </span>c_lock = lock.clone(); |
| |
| <span class="kw">let </span>v = lock.try_read_owned().unwrap(); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>v, <span class="number">1</span>); |
| |
| tokio::spawn(<span class="kw">async move </span>{ |
| <span class="comment">// While main has an active read lock, we acquire one too. |
| </span><span class="kw">let </span>n = c_lock.read_owned().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>n, <span class="number">1</span>); |
| }).<span class="kw">await</span>.expect(<span class="string">"The spawned task has panicked"</span>); |
| |
| <span class="comment">// Drop the guard when spawned task finishes. |
| </span>drop(v); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.write" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#764-804">source</a><h4 class="code-header">pub async fn <a href="#method.write" class="fnname">write</a>(&self) -> <a class="struct" href="struct.RwLockWriteGuard.html" title="struct tokio::sync::RwLockWriteGuard">RwLockWriteGuard</a><'_, T></h4></section></summary><div class="docblock"><p>Locks this <code>RwLock</code> with exclusive write access, causing the current |
| task to yield until the lock has been acquired.</p> |
| <p>The calling task will yield while other writers or readers currently |
| have access to the lock.</p> |
| <p>Returns an RAII guard which will drop the write access of this <code>RwLock</code> |
| when dropped.</p> |
| <h5 id="cancel-safety-2"><a href="#cancel-safety-2">Cancel safety</a></h5> |
| <p>This method uses a queue to fairly distribute locks in the order they |
| were requested. Cancelling a call to <code>write</code> makes you lose your place |
| in the queue.</p> |
| <h5 id="examples-8"><a href="#examples-8">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>lock = RwLock::new(<span class="number">1</span>); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>n = lock.write().<span class="kw">await</span>; |
| <span class="kw-2">*</span>n = <span class="number">2</span>; |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.blocking_write" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#857-859">source</a><h4 class="code-header">pub fn <a href="#method.blocking_write" class="fnname">blocking_write</a>(&self) -> <a class="struct" href="struct.RwLockWriteGuard.html" title="struct tokio::sync::RwLockWriteGuard">RwLockWriteGuard</a><'_, T></h4></section></summary><div class="docblock"><p>Blockingly locks this <code>RwLock</code> with exclusive write access.</p> |
| <p>This method is intended for use cases where you |
| need to use this rwlock in asynchronous code as well as in synchronous code.</p> |
| <p>Returns an RAII guard which will drop the write access of this <code>RwLock</code> when dropped.</p> |
| <h5 id="panics-2"><a href="#panics-2">Panics</a></h5> |
| <p>This function panics if called within an asynchronous execution context.</p> |
| <ul> |
| <li>If you find yourself in an asynchronous execution context and needing |
| to call some (synchronous) function which performs one of these |
| <code>blocking_</code> operations, then consider wrapping that call inside |
| <a href="../runtime/struct.Handle.html#method.spawn_blocking" title="crate::runtime::Handle::spawn_blocking"><code>spawn_blocking()</code></a> |
| (or [<code>block_in_place()</code>][crate::task::block_in_place]).</li> |
| </ul> |
| <h5 id="examples-9"><a href="#examples-9">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::{sync::RwLock}; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>rwlock = Arc::new(RwLock::new(<span class="number">1</span>)); |
| <span class="kw">let </span>read_lock = rwlock.read().<span class="kw">await</span>; |
| |
| <span class="kw">let </span>blocking_task = tokio::task::spawn_blocking({ |
| <span class="kw">let </span>rwlock = Arc::clone(<span class="kw-2">&</span>rwlock); |
| <span class="kw">move </span>|| { |
| <span class="comment">// This shall block until the `read_lock` is released. |
| </span><span class="kw">let </span><span class="kw-2">mut </span>write_lock = rwlock.blocking_write(); |
| <span class="kw-2">*</span>write_lock = <span class="number">2</span>; |
| } |
| }); |
| |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>read_lock, <span class="number">1</span>); |
| <span class="comment">// Release the last outstanding read lock. |
| </span>drop(read_lock); |
| |
| <span class="comment">// Await the completion of the blocking task. |
| </span>blocking_task.<span class="kw">await</span>.unwrap(); |
| |
| <span class="comment">// Assert uncontended. |
| </span><span class="kw">let </span>read_lock = rwlock.try_read().unwrap(); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>read_lock, <span class="number">2</span>); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.write_owned" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#896-939">source</a><h4 class="code-header">pub async fn <a href="#method.write_owned" class="fnname">write_owned</a>(self: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="struct alloc::sync::Arc">Arc</a><Self>) -> <a class="struct" href="struct.OwnedRwLockWriteGuard.html" title="struct tokio::sync::OwnedRwLockWriteGuard">OwnedRwLockWriteGuard</a><T></h4></section></summary><div class="docblock"><p>Locks this <code>RwLock</code> with exclusive write access, causing the current |
| task to yield until the lock has been acquired.</p> |
| <p>The calling task will yield while other writers or readers currently |
| have access to the lock.</p> |
| <p>This method is identical to <a href="struct.RwLock.html#method.write" title="RwLock::write"><code>RwLock::write</code></a>, except that the returned |
| guard references the <code>RwLock</code> with an <a href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="Arc"><code>Arc</code></a> rather than by borrowing |
| it. Therefore, the <code>RwLock</code> must be wrapped in an <code>Arc</code> to call this |
| method, and the guard will live for the <code>'static</code> lifetime, as it keeps |
| the <code>RwLock</code> alive by holding an <code>Arc</code>.</p> |
| <p>Returns an RAII guard which will drop the write access of this <code>RwLock</code> |
| when dropped.</p> |
| <h5 id="cancel-safety-3"><a href="#cancel-safety-3">Cancel safety</a></h5> |
| <p>This method uses a queue to fairly distribute locks in the order they |
| were requested. Cancelling a call to <code>write_owned</code> makes you lose your |
| place in the queue.</p> |
| <h5 id="examples-10"><a href="#examples-10">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>lock = Arc::new(RwLock::new(<span class="number">1</span>)); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>n = lock.write_owned().<span class="kw">await</span>; |
| <span class="kw-2">*</span>n = <span class="number">2</span>; |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_write" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#964-990">source</a><h4 class="code-header">pub fn <a href="#method.try_write" class="fnname">try_write</a>(&self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="struct" href="struct.RwLockWriteGuard.html" title="struct tokio::sync::RwLockWriteGuard">RwLockWriteGuard</a><'_, T>, <a class="struct" href="struct.TryLockError.html" title="struct tokio::sync::TryLockError">TryLockError</a>></h4></section></summary><div class="docblock"><p>Attempts to acquire this <code>RwLock</code> with exclusive write access.</p> |
| <p>If the access couldn’t be acquired immediately, returns <a href="struct.TryLockError.html"><code>TryLockError</code></a>. |
| Otherwise, an RAII guard is returned which will release write access |
| when dropped.</p> |
| <h5 id="examples-11"><a href="#examples-11">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>rw = RwLock::new(<span class="number">1</span>); |
| |
| <span class="kw">let </span>v = rw.read().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>v, <span class="number">1</span>); |
| |
| <span class="macro">assert!</span>(rw.try_write().is_err()); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_write_owned" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1022-1048">source</a><h4 class="code-header">pub fn <a href="#method.try_write_owned" class="fnname">try_write_owned</a>(<br> self: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="struct alloc::sync::Arc">Arc</a><Self><br>) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="struct" href="struct.OwnedRwLockWriteGuard.html" title="struct tokio::sync::OwnedRwLockWriteGuard">OwnedRwLockWriteGuard</a><T>, <a class="struct" href="struct.TryLockError.html" title="struct tokio::sync::TryLockError">TryLockError</a>></h4></section></summary><div class="docblock"><p>Attempts to acquire this <code>RwLock</code> with exclusive write access.</p> |
| <p>If the access couldn’t be acquired immediately, returns <a href="struct.TryLockError.html"><code>TryLockError</code></a>. |
| Otherwise, an RAII guard is returned which will release write access |
| when dropped.</p> |
| <p>This method is identical to <a href="struct.RwLock.html#method.try_write" title="RwLock::try_write"><code>RwLock::try_write</code></a>, except that the |
| returned guard references the <code>RwLock</code> with an <a href="https://doc.rust-lang.org/nightly/alloc/sync/struct.Arc.html" title="Arc"><code>Arc</code></a> rather than by |
| borrowing it. Therefore, the <code>RwLock</code> must be wrapped in an <code>Arc</code> to |
| call this method, and the guard will live for the <code>'static</code> lifetime, |
| as it keeps the <code>RwLock</code> alive by holding an <code>Arc</code>.</p> |
| <h5 id="examples-12"><a href="#examples-12">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="attribute">#[tokio::main] |
| </span><span class="kw">async fn </span>main() { |
| <span class="kw">let </span>rw = Arc::new(RwLock::new(<span class="number">1</span>)); |
| |
| <span class="kw">let </span>v = Arc::clone(<span class="kw-2">&</span>rw).read_owned().<span class="kw">await</span>; |
| <span class="macro">assert_eq!</span>(<span class="kw-2">*</span>v, <span class="number">1</span>); |
| |
| <span class="macro">assert!</span>(rw.try_write_owned().is_err()); |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.get_mut" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1067-1072">source</a><h4 class="code-header">pub fn <a href="#method.get_mut" class="fnname">get_mut</a>(&mut self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&mut </a>T</h4></section></summary><div class="docblock"><p>Returns a mutable reference to the underlying data.</p> |
| <p>Since this call borrows the <code>RwLock</code> mutably, no actual locking needs to |
| take place – the mutable borrow statically guarantees no locks exist.</p> |
| <h5 id="examples-13"><a href="#examples-13">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::sync::RwLock; |
| |
| <span class="kw">fn </span>main() { |
| <span class="kw">let </span><span class="kw-2">mut </span>lock = RwLock::new(<span class="number">1</span>); |
| |
| <span class="kw">let </span>n = lock.get_mut(); |
| <span class="kw-2">*</span>n = <span class="number">2</span>; |
| }</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.into_inner" class="method has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1075-1080">source</a><h4 class="code-header">pub fn <a href="#method.into_inner" class="fnname">into_inner</a>(self) -> T<span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</span></h4></section></summary><div class="docblock"><p>Consumes the lock, returning the underlying data.</p> |
| </div></details></div></details></div><h2 id="trait-implementations" class="small-section-header">Trait Implementations<a href="#trait-implementations" class="anchor"></a></h2><div id="trait-implementations-list"><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-Debug-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1098-1110">source</a><a href="#impl-Debug-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>> <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="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.fmt" class="method trait-impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1102-1109">source</a><a href="#method.fmt" class="anchor"></a><h4 class="code-header">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></h4></section></summary><div class='docblock'>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></div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-Default-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1089-1096">source</a><a href="#impl-Default-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>> <a class="trait" href="https://doc.rust-lang.org/nightly/core/default/trait.Default.html" title="trait core::default::Default">Default</a> for <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/default/trait.Default.html" title="trait core::default::Default">Default</a>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.default" class="method trait-impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1093-1095">source</a><a href="#method.default" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/default/trait.Default.html#tymethod.default" class="fnname">default</a>() -> Self</h4></section></summary><div class='docblock'>Returns the “default value” for a type. <a href="https://doc.rust-lang.org/nightly/core/default/trait.Default.html#tymethod.default">Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-From%3CT%3E-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1083-1087">source</a><a href="#impl-From%3CT%3E-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a><T> for <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from" class="method trait-impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#1084-1086">source</a><a href="#method.from" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from" class="fnname">from</a>(s: T) -> Self</h4></section></summary><div class='docblock'>Converts to this type from the input type.</div></details></div></details><section id="impl-Send-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#149">source</a><a href="#impl-Send-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a>,</span></h3></section><section id="impl-Sync-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="../../src/tokio/sync/rwlock.rs.html#150">source</a><a href="#impl-Sync-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a>,</span></h3></section></div><h2 id="synthetic-implementations" class="small-section-header">Auto Trait Implementations<a href="#synthetic-implementations" class="anchor"></a></h2><div id="synthetic-implementations-list"><section id="impl-RefUnwindSafe-for-RwLock%3CT%3E" class="impl has-srclink"><a href="#impl-RefUnwindSafe-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> !<a class="trait" href="https://doc.rust-lang.org/nightly/core/panic/unwind_safe/trait.RefUnwindSafe.html" title="trait core::panic::unwind_safe::RefUnwindSafe">RefUnwindSafe</a> for <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T></h3></section><section id="impl-Unpin-for-RwLock%3CT%3E" class="impl has-srclink"><a href="#impl-Unpin-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>> <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a> for <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a>,</span></h3></section><section id="impl-UnwindSafe-for-RwLock%3CT%3E" class="impl has-srclink"><a href="#impl-UnwindSafe-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>> <a class="trait" href="https://doc.rust-lang.org/nightly/core/panic/unwind_safe/trait.UnwindSafe.html" title="trait core::panic::unwind_safe::UnwindSafe">UnwindSafe</a> for <a class="struct" href="struct.RwLock.html" title="struct tokio::sync::RwLock">RwLock</a><T><span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/panic/unwind_safe/trait.UnwindSafe.html" title="trait core::panic::unwind_safe::UnwindSafe">UnwindSafe</a>,</span></h3></section></div><h2 id="blanket-implementations" class="small-section-header">Blanket Implementations<a href="#blanket-implementations" class="anchor"></a></h2><div id="blanket-implementations-list"><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Any-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/any.rs.html#200">source</a><a href="#impl-Any-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/any/trait.Any.html" title="trait core::any::Any">Any</a> for T<span class="where fmt-newline">where<br> T: 'static + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.type_id" class="method trait-impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/any.rs.html#201">source</a><a href="#method.type_id" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/any/trait.Any.html#tymethod.type_id" class="fnname">type_id</a>(&self) -> <a class="struct" href="https://doc.rust-lang.org/nightly/core/any/struct.TypeId.html" title="struct core::any::TypeId">TypeId</a></h4></section></summary><div class='docblock'>Gets the <code>TypeId</code> of <code>self</code>. <a href="https://doc.rust-lang.org/nightly/core/any/trait.Any.html#tymethod.type_id">Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Borrow%3CT%3E-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#211">source</a><a href="#impl-Borrow%3CT%3E-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html" title="trait core::borrow::Borrow">Borrow</a><T> for T<span class="where fmt-newline">where<br> T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.borrow" class="method trait-impl has-srclink"><span class="rightside"><span class="since" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/91522" title="Tracking issue for const_borrow">unstable</a></span> · <a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#213">source</a></span><a href="#method.borrow" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow" class="fnname">borrow</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>T</h4></section></summary><div class='docblock'>Immutably borrows from an owned value. <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-BorrowMut%3CT%3E-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#220">source</a><a href="#impl-BorrowMut%3CT%3E-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html" title="trait core::borrow::BorrowMut">BorrowMut</a><T> for T<span class="where fmt-newline">where<br> T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.borrow_mut" class="method trait-impl has-srclink"><span class="rightside"><span class="since" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/91522" title="Tracking issue for const_borrow">unstable</a></span> · <a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#221">source</a></span><a href="#method.borrow_mut" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut" class="fnname">borrow_mut</a>(&mut self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&mut </a>T</h4></section></summary><div class='docblock'>Mutably borrows from an owned value. <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-From%3C!%3E-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#751">source</a><a href="#impl-From%3C!%3E-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.never.html">!</a>> for T</h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from-1" class="method trait-impl has-srclink"><span class="rightside"><span class="since" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span> · <a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#752">source</a></span><a href="#method.from-1" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from" class="fnname">from</a>(t: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.never.html">!</a>) -> T</h4></section></summary><div class='docblock'>Converts to this type from the input type.</div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-From%3CT%3E-for-RwLock%3CT%3E-1" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#733">source</a><a href="#impl-From%3CT%3E-for-RwLock%3CT%3E-1" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a><T> for T</h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from-2" class="method trait-impl has-srclink"><span class="rightside"><span class="since" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span> · <a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#736">source</a></span><a href="#method.from-2" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from" class="fnname">from</a>(t: T) -> T</h4></section></summary><div class="docblock"><p>Returns the argument unchanged.</p> |
| </div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Into%3CU%3E-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#717">source</a><a href="#impl-Into%3CU%3E-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><U> for T<span class="where fmt-newline">where<br> U: <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a><T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.into" class="method trait-impl has-srclink"><span class="rightside"><span class="since" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span> · <a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#725">source</a></span><a href="#method.into" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html#tymethod.into" class="fnname">into</a>(self) -> U</h4></section></summary><div class="docblock"><p>Calls <code>U::from(self)</code>.</p> |
| <p>That is, this conversion is whatever the implementation of |
| <code><a href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="From">From</a><T> for U</code> chooses to do.</p> |
| </div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-TryFrom%3CU%3E-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#775">source</a><a href="#impl-TryFrom%3CU%3E-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U> for T<span class="where fmt-newline">where<br> U: <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><section id="associatedtype.Error-1" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Error-1" class="anchor"></a><h4 class="code-header">type <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" class="associatedtype">Error</a> = <a class="enum" href="https://doc.rust-lang.org/nightly/core/convert/enum.Infallible.html" title="enum core::convert::Infallible">Infallible</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_from" class="method trait-impl has-srclink"><span class="rightside"><span class="since" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span> · <a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#781">source</a></span><a href="#method.try_from" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#tymethod.try_from" class="fnname">try_from</a>(value: U) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, <T as <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U>>::<a class="associatedtype" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-TryInto%3CU%3E-for-RwLock%3CT%3E" class="impl has-srclink"><a class="srclink rightside" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#760">source</a><a href="#impl-TryInto%3CU%3E-for-RwLock%3CT%3E" class="anchor"></a><h3 class="code-header">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html" title="trait core::convert::TryInto">TryInto</a><U> for T<span class="where fmt-newline">where<br> U: <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><section id="associatedtype.Error" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Error" class="anchor"></a><h4 class="code-header">type <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html#associatedtype.Error" class="associatedtype">Error</a> = <U as <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="associatedtype" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_into" class="method trait-impl has-srclink"><span class="rightside"><span class="since" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span> · <a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#766">source</a></span><a href="#method.try_into" class="anchor"></a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html#tymethod.try_into" class="fnname">try_into</a>(self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><U, <U as <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="associatedtype" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details></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> |
