<!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 to the Rust file `src/libstd/sync/condvar.rs`."> <meta name="keywords" content="rust, rustlang, rust-lang"> <title>condvar.rs.html -- source</title> <link rel="stylesheet" type="text/css" href="../../../normalize.css"> <link rel="stylesheet" type="text/css" href="../../../rustdoc.css"> <link rel="stylesheet" type="text/css" href="../../../main.css"> <link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"> </head> <body class="rustdoc source"> <!--[if lte IE 8]> <div class="warning"> This old browser is unsupported and will most likely display funky things. </div> <![endif]--> <nav class="sidebar"> <a href='../../../std/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a> </nav> <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"><pre class="line-numbers"><span id="1"> 1</span> <span id="2"> 2</span> <span id="3"> 3</span> <span id="4"> 4</span> <span id="5"> 5</span> <span id="6"> 6</span> <span id="7"> 7</span> <span id="8"> 8</span> <span id="9"> 9</span> <span id="10"> 10</span> <span id="11"> 11</span> <span id="12"> 12</span> <span id="13"> 13</span> <span id="14"> 14</span> <span id="15"> 15</span> <span id="16"> 16</span> <span id="17"> 17</span> <span id="18"> 18</span> <span id="19"> 19</span> <span id="20"> 20</span> <span id="21"> 21</span> <span id="22"> 22</span> <span id="23"> 23</span> <span id="24"> 24</span> <span id="25"> 25</span> <span id="26"> 26</span> <span id="27"> 27</span> <span id="28"> 28</span> <span id="29"> 29</span> 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id="565">565</span> <span id="566">566</span> <span id="567">567</span> <span id="568">568</span> <span id="569">569</span> <span id="570">570</span> <span id="571">571</span> <span id="572">572</span> <span id="573">573</span> <span id="574">574</span> <span id="575">575</span> <span id="576">576</span> <span id="577">577</span> <span id="578">578</span> <span id="579">579</span> <span id="580">580</span> <span id="581">581</span> <span id="582">582</span> <span id="583">583</span> <span id="584">584</span> <span id="585">585</span> <span id="586">586</span> <span id="587">587</span> <span id="588">588</span> <span id="589">589</span> </pre><pre class="rust "> <span class="comment">// Copyright 2014 The Rust Project Developers. See the COPYRIGHT</span> <span class="comment">// file at the top-level directory of this distribution and at</span> <span class="comment">// http://rust-lang.org/COPYRIGHT.</span> <span class="comment">//</span> <span class="comment">// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span> <span class="comment">// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span> <span class="comment">// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your</span> <span class="comment">// option. This file may not be copied, modified, or distributed</span> <span class="comment">// except according to those terms.</span> <span class="kw">use</span> <span class="ident">fmt</span>; <span class="kw">use</span> <span class="ident">sync</span>::<span class="ident">atomic</span>::{<span class="ident">AtomicUsize</span>, <span class="ident">Ordering</span>}; <span class="kw">use</span> <span class="ident">sync</span>::{<span class="ident">mutex</span>, <span class="ident">MutexGuard</span>, <span class="ident">PoisonError</span>}; <span class="kw">use</span> <span class="ident">sys_common</span>::<span class="ident">condvar</span> <span class="kw">as</span> <span class="ident">sys</span>; <span class="kw">use</span> <span class="ident">sys_common</span>::<span class="ident">mutex</span> <span class="kw">as</span> <span class="ident">sys_mutex</span>; <span class="kw">use</span> <span class="ident">sys_common</span>::<span class="ident">poison</span>::{<span class="self">self</span>, <span class="ident">LockResult</span>}; <span class="kw">use</span> <span class="ident">time</span>::<span class="ident">Duration</span>; <span class="doccomment">/// A type indicating whether a timed wait on a condition variable returned</span> <span class="doccomment">/// due to a time out or not.</span> <span class="doccomment">///</span> <span class="doccomment">/// It is returned by the [`wait_timeout`] method.</span> <span class="doccomment">///</span> <span class="doccomment">/// [`wait_timeout`]: struct.Condvar.html#method.wait_timeout</span> <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>, <span class="ident">PartialEq</span>, <span class="ident">Eq</span>, <span class="ident">Copy</span>, <span class="ident">Clone</span>)]</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"wait_timeout"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.5.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">WaitTimeoutResult</span>(<span class="ident">bool</span>); <span class="kw">impl</span> <span class="ident">WaitTimeoutResult</span> { <span class="doccomment">/// Returns whether the wait was known to have timed out.</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// This example spawns a thread which will update the boolean value and</span> <span class="doccomment">/// then wait 100 milliseconds before notifying the condvar.</span> <span class="doccomment">///</span> <span class="doccomment">/// The main thread will wait with a timeout on the condvar and then leave</span> <span class="doccomment">/// once the boolean has been updated and notified.</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::{Arc, Mutex, Condvar};</span> <span class="doccomment">/// use std::thread;</span> <span class="doccomment">/// use std::time::Duration;</span> <span class="doccomment">///</span> <span class="doccomment">/// let pair = Arc::new((Mutex::new(false), Condvar::new()));</span> <span class="doccomment">/// let pair2 = pair.clone();</span> <span class="doccomment">///</span> <span class="doccomment">/// thread::spawn(move|| {</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair2;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// // We update the boolean value.</span> <span class="doccomment">/// *started = true;</span> <span class="doccomment">/// // Let's wait 20 milliseconds before notifying the condvar.</span> <span class="doccomment">/// thread::sleep(Duration::from_millis(20));</span> <span class="doccomment">/// cvar.notify_one();</span> <span class="doccomment">/// });</span> <span class="doccomment">///</span> <span class="doccomment">/// // Wait for the thread to start up.</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// loop {</span> <span class="doccomment">/// // Let's put a timeout on the condvar's wait.</span> <span class="doccomment">/// let result = cvar.wait_timeout(started, Duration::from_millis(10)).unwrap();</span> <span class="doccomment">/// // 10 milliseconds have passed, or maybe the value changed!</span> <span class="doccomment">/// started = result.0;</span> <span class="doccomment">/// if *started == true {</span> <span class="doccomment">/// // We received the notification and the value has been updated, we can leave.</span> <span class="doccomment">/// break</span> <span class="doccomment">/// }</span> <span class="doccomment">/// }</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"wait_timeout"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.5.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">timed_out</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">bool</span> { <span class="self">self</span>.<span class="number">0</span> } } <span class="doccomment">/// A Condition Variable</span> <span class="doccomment">///</span> <span class="doccomment">/// Condition variables represent the ability to block a thread such that it</span> <span class="doccomment">/// consumes no CPU time while waiting for an event to occur. Condition</span> <span class="doccomment">/// variables are typically associated with a boolean predicate (a condition)</span> <span class="doccomment">/// and a mutex. The predicate is always verified inside of the mutex before</span> <span class="doccomment">/// determining that a thread must block.</span> <span class="doccomment">///</span> <span class="doccomment">/// Functions in this module will block the current **thread** of execution and</span> <span class="doccomment">/// are bindings to system-provided condition variables where possible. Note</span> <span class="doccomment">/// that this module places one additional restriction over the system condition</span> <span class="doccomment">/// variables: each condvar can be used with precisely one mutex at runtime. Any</span> <span class="doccomment">/// attempt to use multiple mutexes on the same condition variable will result</span> <span class="doccomment">/// in a runtime panic. If this is not desired, then the unsafe primitives in</span> <span class="doccomment">/// `sys` do not have this restriction but may result in undefined behavior.</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::{Arc, Mutex, Condvar};</span> <span class="doccomment">/// use std::thread;</span> <span class="doccomment">///</span> <span class="doccomment">/// let pair = Arc::new((Mutex::new(false), Condvar::new()));</span> <span class="doccomment">/// let pair2 = pair.clone();</span> <span class="doccomment">///</span> <span class="doccomment">/// // Inside of our lock, spawn a new thread, and then wait for it to start.</span> <span class="doccomment">/// thread::spawn(move|| {</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair2;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// *started = true;</span> <span class="doccomment">/// // We notify the condvar that the value has changed.</span> <span class="doccomment">/// cvar.notify_one();</span> <span class="doccomment">/// });</span> <span class="doccomment">///</span> <span class="doccomment">/// // Wait for the thread to start up.</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// while !*started {</span> <span class="doccomment">/// started = cvar.wait(started).unwrap();</span> <span class="doccomment">/// }</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Condvar</span> { <span class="ident">inner</span>: <span class="ident">Box</span><span class="op"><</span><span class="ident">sys</span>::<span class="ident">Condvar</span><span class="op">></span>, <span class="ident">mutex</span>: <span class="ident">AtomicUsize</span>, } <span class="kw">impl</span> <span class="ident">Condvar</span> { <span class="doccomment">/// Creates a new condition variable which is ready to be waited on and</span> <span class="doccomment">/// notified.</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::Condvar;</span> <span class="doccomment">///</span> <span class="doccomment">/// let condvar = Condvar::new();</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>() <span class="op">-></span> <span class="ident">Condvar</span> { <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">Condvar</span> { <span class="ident">inner</span>: <span class="kw">box</span> <span class="ident">sys</span>::<span class="ident">Condvar</span>::<span class="ident">new</span>(), <span class="ident">mutex</span>: <span class="ident">AtomicUsize</span>::<span class="ident">new</span>(<span class="number">0</span>), }; <span class="kw">unsafe</span> { <span class="ident">c</span>.<span class="ident">inner</span>.<span class="ident">init</span>(); } <span class="ident">c</span> } <span class="doccomment">/// Blocks the current thread until this condition variable receives a</span> <span class="doccomment">/// notification.</span> <span class="doccomment">///</span> <span class="doccomment">/// This function will atomically unlock the mutex specified (represented by</span> <span class="doccomment">/// `guard`) and block the current thread. This means that any calls</span> <span class="doccomment">/// to [`notify_one`] or [`notify_all`] which happen logically after the</span> <span class="doccomment">/// mutex is unlocked are candidates to wake this thread up. When this</span> <span class="doccomment">/// function call returns, the lock specified will have been re-acquired.</span> <span class="doccomment">///</span> <span class="doccomment">/// Note that this function is susceptible to spurious wakeups. Condition</span> <span class="doccomment">/// variables normally have a boolean predicate associated with them, and</span> <span class="doccomment">/// the predicate must always be checked each time this function returns to</span> <span class="doccomment">/// protect against spurious wakeups.</span> <span class="doccomment">///</span> <span class="doccomment">/// # Errors</span> <span class="doccomment">///</span> <span class="doccomment">/// This function will return an error if the mutex being waited on is</span> <span class="doccomment">/// poisoned when this thread re-acquires the lock. For more information,</span> <span class="doccomment">/// see information about [poisoning] on the [`Mutex`] type.</span> <span class="doccomment">///</span> <span class="doccomment">/// # Panics</span> <span class="doccomment">///</span> <span class="doccomment">/// This function will [`panic!`] if it is used with more than one mutex</span> <span class="doccomment">/// over time. Each condition variable is dynamically bound to exactly one</span> <span class="doccomment">/// mutex to ensure defined behavior across platforms. If this functionality</span> <span class="doccomment">/// is not desired, then unsafe primitives in `sys` are provided.</span> <span class="doccomment">///</span> <span class="doccomment">/// [`notify_one`]: #method.notify_one</span> <span class="doccomment">/// [`notify_all`]: #method.notify_all</span> <span class="doccomment">/// [poisoning]: ../sync/struct.Mutex.html#poisoning</span> <span class="doccomment">/// [`Mutex`]: ../sync/struct.Mutex.html</span> <span class="doccomment">/// [`panic!`]: ../../std/macro.panic.html</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::{Arc, Mutex, Condvar};</span> <span class="doccomment">/// use std::thread;</span> <span class="doccomment">///</span> <span class="doccomment">/// let pair = Arc::new((Mutex::new(false), Condvar::new()));</span> <span class="doccomment">/// let pair2 = pair.clone();</span> <span class="doccomment">///</span> <span class="doccomment">/// thread::spawn(move|| {</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair2;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// *started = true;</span> <span class="doccomment">/// // We notify the condvar that the value has changed.</span> <span class="doccomment">/// cvar.notify_one();</span> <span class="doccomment">/// });</span> <span class="doccomment">///</span> <span class="doccomment">/// // Wait for the thread to start up.</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// // As long as the value inside the `Mutex` is false, we wait.</span> <span class="doccomment">/// while !*started {</span> <span class="doccomment">/// started = cvar.wait(started).unwrap();</span> <span class="doccomment">/// }</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">guard</span>: <span class="ident">MutexGuard</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>) <span class="op">-></span> <span class="ident">LockResult</span><span class="op"><</span><span class="ident">MutexGuard</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">>></span> { <span class="kw">let</span> <span class="ident">poisoned</span> <span class="op">=</span> <span class="kw">unsafe</span> { <span class="kw">let</span> <span class="ident">lock</span> <span class="op">=</span> <span class="ident">mutex</span>::<span class="ident">guard_lock</span>(<span class="kw-2">&</span><span class="ident">guard</span>); <span class="self">self</span>.<span class="ident">verify</span>(<span class="ident">lock</span>); <span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">wait</span>(<span class="ident">lock</span>); <span class="ident">mutex</span>::<span class="ident">guard_poison</span>(<span class="kw-2">&</span><span class="ident">guard</span>).<span class="ident">get</span>() }; <span class="kw">if</span> <span class="ident">poisoned</span> { <span class="prelude-val">Err</span>(<span class="ident">PoisonError</span>::<span class="ident">new</span>(<span class="ident">guard</span>)) } <span class="kw">else</span> { <span class="prelude-val">Ok</span>(<span class="ident">guard</span>) } } <span class="doccomment">/// Waits on this condition variable for a notification, timing out after a</span> <span class="doccomment">/// specified duration.</span> <span class="doccomment">///</span> <span class="doccomment">/// The semantics of this function are equivalent to [`wait`]</span> <span class="doccomment">/// except that the thread will be blocked for roughly no longer</span> <span class="doccomment">/// than `ms` milliseconds. This method should not be used for</span> <span class="doccomment">/// precise timing due to anomalies such as preemption or platform</span> <span class="doccomment">/// differences that may not cause the maximum amount of time</span> <span class="doccomment">/// waited to be precisely `ms`.</span> <span class="doccomment">///</span> <span class="doccomment">/// Note that the best effort is made to ensure that the time waited is</span> <span class="doccomment">/// measured with a monotonic clock, and not affected by the changes made to</span> <span class="doccomment">/// the system time.</span> <span class="doccomment">///</span> <span class="doccomment">/// The returned boolean is `false` only if the timeout is known</span> <span class="doccomment">/// to have elapsed.</span> <span class="doccomment">///</span> <span class="doccomment">/// Like [`wait`], the lock specified will be re-acquired when this function</span> <span class="doccomment">/// returns, regardless of whether the timeout elapsed or not.</span> <span class="doccomment">///</span> <span class="doccomment">/// [`wait`]: #method.wait</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::{Arc, Mutex, Condvar};</span> <span class="doccomment">/// use std::thread;</span> <span class="doccomment">///</span> <span class="doccomment">/// let pair = Arc::new((Mutex::new(false), Condvar::new()));</span> <span class="doccomment">/// let pair2 = pair.clone();</span> <span class="doccomment">///</span> <span class="doccomment">/// thread::spawn(move|| {</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair2;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// *started = true;</span> <span class="doccomment">/// // We notify the condvar that the value has changed.</span> <span class="doccomment">/// cvar.notify_one();</span> <span class="doccomment">/// });</span> <span class="doccomment">///</span> <span class="doccomment">/// // Wait for the thread to start up.</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// // As long as the value inside the `Mutex` is false, we wait.</span> <span class="doccomment">/// loop {</span> <span class="doccomment">/// let result = cvar.wait_timeout_ms(started, 10).unwrap();</span> <span class="doccomment">/// // 10 milliseconds have passed, or maybe the value changed!</span> <span class="doccomment">/// started = result.0;</span> <span class="doccomment">/// if *started == true {</span> <span class="doccomment">/// // We received the notification and the value has been updated, we can leave.</span> <span class="doccomment">/// break</span> <span class="doccomment">/// }</span> <span class="doccomment">/// }</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span> <span class="attribute">#[<span class="ident">rustc_deprecated</span>(<span class="ident">since</span> <span class="op">=</span> <span class="string">"1.6.0"</span>, <span class="ident">reason</span> <span class="op">=</span> <span class="string">"replaced by `std::sync::Condvar::wait_timeout`"</span>)]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_timeout_ms</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">guard</span>: <span class="ident">MutexGuard</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>, <span class="ident">ms</span>: <span class="ident">u32</span>) <span class="op">-></span> <span class="ident">LockResult</span><span class="op"><</span>(<span class="ident">MutexGuard</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>, <span class="ident">bool</span>)<span class="op">></span> { <span class="kw">let</span> <span class="ident">res</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">wait_timeout</span>(<span class="ident">guard</span>, <span class="ident">Duration</span>::<span class="ident">from_millis</span>(<span class="ident">ms</span> <span class="kw">as</span> <span class="ident">u64</span>)); <span class="ident">poison</span>::<span class="ident">map_result</span>(<span class="ident">res</span>, <span class="op">|</span>(<span class="ident">a</span>, <span class="ident">b</span>)<span class="op">|</span> { (<span class="ident">a</span>, <span class="op">!</span><span class="ident">b</span>.<span class="ident">timed_out</span>()) }) } <span class="doccomment">/// Waits on this condition variable for a notification, timing out after a</span> <span class="doccomment">/// specified duration.</span> <span class="doccomment">///</span> <span class="doccomment">/// The semantics of this function are equivalent to [`wait`] except that</span> <span class="doccomment">/// the thread will be blocked for roughly no longer than `dur`. This</span> <span class="doccomment">/// method should not be used for precise timing due to anomalies such as</span> <span class="doccomment">/// preemption or platform differences that may not cause the maximum</span> <span class="doccomment">/// amount of time waited to be precisely `dur`.</span> <span class="doccomment">///</span> <span class="doccomment">/// Note that the best effort is made to ensure that the time waited is</span> <span class="doccomment">/// measured with a monotonic clock, and not affected by the changes made to</span> <span class="doccomment">/// the system time.</span> <span class="doccomment">///</span> <span class="doccomment">/// The returned [`WaitTimeoutResult`] value indicates if the timeout is</span> <span class="doccomment">/// known to have elapsed.</span> <span class="doccomment">///</span> <span class="doccomment">/// Like [`wait`], the lock specified will be re-acquired when this function</span> <span class="doccomment">/// returns, regardless of whether the timeout elapsed or not.</span> <span class="doccomment">///</span> <span class="doccomment">/// [`wait`]: #method.wait</span> <span class="doccomment">/// [`WaitTimeoutResult`]: struct.WaitTimeoutResult.html</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::{Arc, Mutex, Condvar};</span> <span class="doccomment">/// use std::thread;</span> <span class="doccomment">/// use std::time::Duration;</span> <span class="doccomment">///</span> <span class="doccomment">/// let pair = Arc::new((Mutex::new(false), Condvar::new()));</span> <span class="doccomment">/// let pair2 = pair.clone();</span> <span class="doccomment">///</span> <span class="doccomment">/// thread::spawn(move|| {</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair2;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// *started = true;</span> <span class="doccomment">/// // We notify the condvar that the value has changed.</span> <span class="doccomment">/// cvar.notify_one();</span> <span class="doccomment">/// });</span> <span class="doccomment">///</span> <span class="doccomment">/// // wait for the thread to start up</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// // as long as the value inside the `Mutex` is false, we wait</span> <span class="doccomment">/// loop {</span> <span class="doccomment">/// let result = cvar.wait_timeout(started, Duration::from_millis(10)).unwrap();</span> <span class="doccomment">/// // 10 milliseconds have passed, or maybe the value changed!</span> <span class="doccomment">/// started = result.0;</span> <span class="doccomment">/// if *started == true {</span> <span class="doccomment">/// // We received the notification and the value has been updated, we can leave.</span> <span class="doccomment">/// break</span> <span class="doccomment">/// }</span> <span class="doccomment">/// }</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"wait_timeout"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.5.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_timeout</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">guard</span>: <span class="ident">MutexGuard</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>, <span class="ident">dur</span>: <span class="ident">Duration</span>) <span class="op">-></span> <span class="ident">LockResult</span><span class="op"><</span>(<span class="ident">MutexGuard</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">T</span><span class="op">></span>, <span class="ident">WaitTimeoutResult</span>)<span class="op">></span> { <span class="kw">let</span> (<span class="ident">poisoned</span>, <span class="ident">result</span>) <span class="op">=</span> <span class="kw">unsafe</span> { <span class="kw">let</span> <span class="ident">lock</span> <span class="op">=</span> <span class="ident">mutex</span>::<span class="ident">guard_lock</span>(<span class="kw-2">&</span><span class="ident">guard</span>); <span class="self">self</span>.<span class="ident">verify</span>(<span class="ident">lock</span>); <span class="kw">let</span> <span class="ident">success</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">wait_timeout</span>(<span class="ident">lock</span>, <span class="ident">dur</span>); (<span class="ident">mutex</span>::<span class="ident">guard_poison</span>(<span class="kw-2">&</span><span class="ident">guard</span>).<span class="ident">get</span>(), <span class="ident">WaitTimeoutResult</span>(<span class="op">!</span><span class="ident">success</span>)) }; <span class="kw">if</span> <span class="ident">poisoned</span> { <span class="prelude-val">Err</span>(<span class="ident">PoisonError</span>::<span class="ident">new</span>((<span class="ident">guard</span>, <span class="ident">result</span>))) } <span class="kw">else</span> { <span class="prelude-val">Ok</span>((<span class="ident">guard</span>, <span class="ident">result</span>)) } } <span class="doccomment">/// Wakes up one blocked thread on this condvar.</span> <span class="doccomment">///</span> <span class="doccomment">/// If there is a blocked thread on this condition variable, then it will</span> <span class="doccomment">/// be woken up from its call to [`wait`] or [`wait_timeout`]. Calls to</span> <span class="doccomment">/// `notify_one` are not buffered in any way.</span> <span class="doccomment">///</span> <span class="doccomment">/// To wake up all threads, see [`notify_all`].</span> <span class="doccomment">///</span> <span class="doccomment">/// [`wait`]: #method.wait</span> <span class="doccomment">/// [`wait_timeout`]: #method.wait_timeout</span> <span class="doccomment">/// [`notify_all`]: #method.notify_all</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::{Arc, Mutex, Condvar};</span> <span class="doccomment">/// use std::thread;</span> <span class="doccomment">///</span> <span class="doccomment">/// let pair = Arc::new((Mutex::new(false), Condvar::new()));</span> <span class="doccomment">/// let pair2 = pair.clone();</span> <span class="doccomment">///</span> <span class="doccomment">/// thread::spawn(move|| {</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair2;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// *started = true;</span> <span class="doccomment">/// // We notify the condvar that the value has changed.</span> <span class="doccomment">/// cvar.notify_one();</span> <span class="doccomment">/// });</span> <span class="doccomment">///</span> <span class="doccomment">/// // Wait for the thread to start up.</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// // As long as the value inside the `Mutex` is false, we wait.</span> <span class="doccomment">/// while !*started {</span> <span class="doccomment">/// started = cvar.wait(started).unwrap();</span> <span class="doccomment">/// }</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">notify_one</span>(<span class="kw-2">&</span><span class="self">self</span>) { <span class="kw">unsafe</span> { <span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">notify_one</span>() } } <span class="doccomment">/// Wakes up all blocked threads on this condvar.</span> <span class="doccomment">///</span> <span class="doccomment">/// This method will ensure that any current waiters on the condition</span> <span class="doccomment">/// variable are awoken. Calls to `notify_all()` are not buffered in any</span> <span class="doccomment">/// way.</span> <span class="doccomment">///</span> <span class="doccomment">/// To wake up only one thread, see [`notify_one`].</span> <span class="doccomment">///</span> <span class="doccomment">/// [`notify_one`]: #method.notify_one</span> <span class="doccomment">///</span> <span class="doccomment">/// # Examples</span> <span class="doccomment">///</span> <span class="doccomment">/// ```</span> <span class="doccomment">/// use std::sync::{Arc, Mutex, Condvar};</span> <span class="doccomment">/// use std::thread;</span> <span class="doccomment">///</span> <span class="doccomment">/// let pair = Arc::new((Mutex::new(false), Condvar::new()));</span> <span class="doccomment">/// let pair2 = pair.clone();</span> <span class="doccomment">///</span> <span class="doccomment">/// thread::spawn(move|| {</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair2;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// *started = true;</span> <span class="doccomment">/// // We notify the condvar that the value has changed.</span> <span class="doccomment">/// cvar.notify_all();</span> <span class="doccomment">/// });</span> <span class="doccomment">///</span> <span class="doccomment">/// // Wait for the thread to start up.</span> <span class="doccomment">/// let &(ref lock, ref cvar) = &*pair;</span> <span class="doccomment">/// let mut started = lock.lock().unwrap();</span> <span class="doccomment">/// // As long as the value inside the `Mutex` is false, we wait.</span> <span class="doccomment">/// while !*started {</span> <span class="doccomment">/// started = cvar.wait(started).unwrap();</span> <span class="doccomment">/// }</span> <span class="doccomment">/// ```</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">notify_all</span>(<span class="kw-2">&</span><span class="self">self</span>) { <span class="kw">unsafe</span> { <span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">notify_all</span>() } } <span class="kw">fn</span> <span class="ident">verify</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">mutex</span>: <span class="kw-2">&</span><span class="ident">sys_mutex</span>::<span class="ident">Mutex</span>) { <span class="kw">let</span> <span class="ident">addr</span> <span class="op">=</span> <span class="ident">mutex</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> _ <span class="kw">as</span> <span class="ident">usize</span>; <span class="kw">match</span> <span class="self">self</span>.<span class="ident">mutex</span>.<span class="ident">compare_and_swap</span>(<span class="number">0</span>, <span class="ident">addr</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) { <span class="comment">// If we got out 0, then we have successfully bound the mutex to</span> <span class="comment">// this cvar.</span> <span class="number">0</span> <span class="op">=></span> {} <span class="comment">// If we get out a value that's the same as `addr`, then someone</span> <span class="comment">// already beat us to the punch.</span> <span class="ident">n</span> <span class="kw">if</span> <span class="ident">n</span> <span class="op">==</span> <span class="ident">addr</span> <span class="op">=></span> {} <span class="comment">// Anything else and we're using more than one mutex on this cvar,</span> <span class="comment">// which is currently disallowed.</span> _ <span class="op">=></span> <span class="macro">panic</span><span class="macro">!</span>(<span class="string">"attempted to use a condition variable with two \ mutexes"</span>), } } } <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std_debug"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.16.0"</span>)]</span> <span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Condvar</span> { <span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> { <span class="ident">f</span>.<span class="ident">pad</span>(<span class="string">"Condvar { .. }"</span>) } } <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"condvar_default"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.10.0"</span>)]</span> <span class="kw">impl</span> <span class="ident">Default</span> <span class="kw">for</span> <span class="ident">Condvar</span> { <span class="doccomment">/// Creates a `Condvar` which is ready to be waited on and notified.</span> <span class="kw">fn</span> <span class="ident">default</span>() <span class="op">-></span> <span class="ident">Condvar</span> { <span class="ident">Condvar</span>::<span class="ident">new</span>() } } <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span> <span class="kw">impl</span> <span class="ident">Drop</span> <span class="kw">for</span> <span class="ident">Condvar</span> { <span class="kw">fn</span> <span class="ident">drop</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) { <span class="kw">unsafe</span> { <span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">destroy</span>() } } } <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span> <span class="kw">mod</span> <span class="ident">tests</span> { <span class="kw">use</span> <span class="ident">sync</span>::<span class="ident">mpsc</span>::<span class="ident">channel</span>; <span class="kw">use</span> <span class="ident">sync</span>::{<span class="ident">Condvar</span>, <span class="ident">Mutex</span>, <span class="ident">Arc</span>}; <span class="kw">use</span> <span class="ident">thread</span>; <span class="kw">use</span> <span class="ident">time</span>::<span class="ident">Duration</span>; <span class="kw">use</span> <span class="ident">u32</span>; <span class="attribute">#[<span class="ident">test</span>]</span> <span class="kw">fn</span> <span class="ident">smoke</span>() { <span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">Condvar</span>::<span class="ident">new</span>(); <span class="ident">c</span>.<span class="ident">notify_one</span>(); <span class="ident">c</span>.<span class="ident">notify_all</span>(); } <span class="attribute">#[<span class="ident">test</span>]</span> <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>, <span class="ident">ignore</span>)]</span> <span class="kw">fn</span> <span class="ident">notify_one</span>() { <span class="kw">let</span> <span class="ident">m</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">Mutex</span>::<span class="ident">new</span>(())); <span class="kw">let</span> <span class="ident">m2</span> <span class="op">=</span> <span class="ident">m</span>.<span class="ident">clone</span>(); <span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">Condvar</span>::<span class="ident">new</span>()); <span class="kw">let</span> <span class="ident">c2</span> <span class="op">=</span> <span class="ident">c</span>.<span class="ident">clone</span>(); <span class="kw">let</span> <span class="ident">g</span> <span class="op">=</span> <span class="ident">m</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="kw">let</span> <span class="ident">_t</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">spawn</span>(<span class="kw">move</span><span class="op">||</span> { <span class="kw">let</span> <span class="ident">_g</span> <span class="op">=</span> <span class="ident">m2</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="ident">c2</span>.<span class="ident">notify_one</span>(); }); <span class="kw">let</span> <span class="ident">g</span> <span class="op">=</span> <span class="ident">c</span>.<span class="ident">wait</span>(<span class="ident">g</span>).<span class="ident">unwrap</span>(); <span class="ident">drop</span>(<span class="ident">g</span>); } <span class="attribute">#[<span class="ident">test</span>]</span> <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>, <span class="ident">ignore</span>)]</span> <span class="kw">fn</span> <span class="ident">notify_all</span>() { <span class="kw">const</span> <span class="ident">N</span>: <span class="ident">usize</span> <span class="op">=</span> <span class="number">10</span>; <span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>((<span class="ident">Mutex</span>::<span class="ident">new</span>(<span class="number">0</span>), <span class="ident">Condvar</span>::<span class="ident">new</span>())); <span class="kw">let</span> (<span class="ident">tx</span>, <span class="ident">rx</span>) <span class="op">=</span> <span class="ident">channel</span>(); <span class="kw">for</span> _ <span class="kw">in</span> <span class="number">0</span>..<span class="ident">N</span> { <span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="ident">data</span>.<span class="ident">clone</span>(); <span class="kw">let</span> <span class="ident">tx</span> <span class="op">=</span> <span class="ident">tx</span>.<span class="ident">clone</span>(); <span class="ident">thread</span>::<span class="ident">spawn</span>(<span class="kw">move</span><span class="op">||</span> { <span class="kw">let</span> <span class="kw-2">&</span>(<span class="kw-2">ref</span> <span class="ident">lock</span>, <span class="kw-2">ref</span> <span class="ident">cond</span>) <span class="op">=</span> <span class="kw-2">&</span><span class="kw-2">*</span><span class="ident">data</span>; <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">cnt</span> <span class="op">=</span> <span class="ident">lock</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="kw-2">*</span><span class="ident">cnt</span> <span class="op">+=</span> <span class="number">1</span>; <span class="kw">if</span> <span class="kw-2">*</span><span class="ident">cnt</span> <span class="op">==</span> <span class="ident">N</span> { <span class="ident">tx</span>.<span class="ident">send</span>(()).<span class="ident">unwrap</span>(); } <span class="kw">while</span> <span class="kw-2">*</span><span class="ident">cnt</span> <span class="op">!=</span> <span class="number">0</span> { <span class="ident">cnt</span> <span class="op">=</span> <span class="ident">cond</span>.<span class="ident">wait</span>(<span class="ident">cnt</span>).<span class="ident">unwrap</span>(); } <span class="ident">tx</span>.<span class="ident">send</span>(()).<span class="ident">unwrap</span>(); }); } <span class="ident">drop</span>(<span class="ident">tx</span>); <span class="kw">let</span> <span class="kw-2">&</span>(<span class="kw-2">ref</span> <span class="ident">lock</span>, <span class="kw-2">ref</span> <span class="ident">cond</span>) <span class="op">=</span> <span class="kw-2">&</span><span class="kw-2">*</span><span class="ident">data</span>; <span class="ident">rx</span>.<span class="ident">recv</span>().<span class="ident">unwrap</span>(); <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">cnt</span> <span class="op">=</span> <span class="ident">lock</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="kw-2">*</span><span class="ident">cnt</span> <span class="op">=</span> <span class="number">0</span>; <span class="ident">cond</span>.<span class="ident">notify_all</span>(); <span class="ident">drop</span>(<span class="ident">cnt</span>); <span class="kw">for</span> _ <span class="kw">in</span> <span class="number">0</span>..<span class="ident">N</span> { <span class="ident">rx</span>.<span class="ident">recv</span>().<span class="ident">unwrap</span>(); } } <span class="attribute">#[<span class="ident">test</span>]</span> <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>, <span class="ident">ignore</span>)]</span> <span class="kw">fn</span> <span class="ident">wait_timeout_ms</span>() { <span class="kw">let</span> <span class="ident">m</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">Mutex</span>::<span class="ident">new</span>(())); <span class="kw">let</span> <span class="ident">m2</span> <span class="op">=</span> <span class="ident">m</span>.<span class="ident">clone</span>(); <span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">Condvar</span>::<span class="ident">new</span>()); <span class="kw">let</span> <span class="ident">c2</span> <span class="op">=</span> <span class="ident">c</span>.<span class="ident">clone</span>(); <span class="kw">let</span> <span class="ident">g</span> <span class="op">=</span> <span class="ident">m</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="kw">let</span> (<span class="ident">g</span>, <span class="ident">_no_timeout</span>) <span class="op">=</span> <span class="ident">c</span>.<span class="ident">wait_timeout</span>(<span class="ident">g</span>, <span class="ident">Duration</span>::<span class="ident">from_millis</span>(<span class="number">1</span>)).<span class="ident">unwrap</span>(); <span class="comment">// spurious wakeups mean this isn't necessarily true</span> <span class="comment">// assert!(!no_timeout);</span> <span class="kw">let</span> <span class="ident">_t</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">spawn</span>(<span class="kw">move</span> <span class="op">||</span> { <span class="kw">let</span> <span class="ident">_g</span> <span class="op">=</span> <span class="ident">m2</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="ident">c2</span>.<span class="ident">notify_one</span>(); }); <span class="kw">let</span> (<span class="ident">g</span>, <span class="ident">timeout_res</span>) <span class="op">=</span> <span class="ident">c</span>.<span class="ident">wait_timeout</span>(<span class="ident">g</span>, <span class="ident">Duration</span>::<span class="ident">from_millis</span>(<span class="ident">u32</span>::<span class="ident">MAX</span> <span class="kw">as</span> <span class="ident">u64</span>)).<span class="ident">unwrap</span>(); <span class="macro">assert</span><span class="macro">!</span>(<span class="op">!</span><span class="ident">timeout_res</span>.<span class="ident">timed_out</span>()); <span class="ident">drop</span>(<span class="ident">g</span>); } <span class="attribute">#[<span class="ident">test</span>]</span> <span class="attribute">#[<span class="ident">should_panic</span>]</span> <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>, <span class="ident">ignore</span>)]</span> <span class="kw">fn</span> <span class="ident">two_mutexes</span>() { <span class="kw">let</span> <span class="ident">m</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">Mutex</span>::<span class="ident">new</span>(())); <span class="kw">let</span> <span class="ident">m2</span> <span class="op">=</span> <span class="ident">m</span>.<span class="ident">clone</span>(); <span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">Condvar</span>::<span class="ident">new</span>()); <span class="kw">let</span> <span class="ident">c2</span> <span class="op">=</span> <span class="ident">c</span>.<span class="ident">clone</span>(); <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">g</span> <span class="op">=</span> <span class="ident">m</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="kw">let</span> <span class="ident">_t</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">spawn</span>(<span class="kw">move</span><span class="op">||</span> { <span class="kw">let</span> <span class="ident">_g</span> <span class="op">=</span> <span class="ident">m2</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>(); <span class="ident">c2</span>.<span class="ident">notify_one</span>(); }); <span class="ident">g</span> <span class="op">=</span> <span class="ident">c</span>.<span class="ident">wait</span>(<span class="ident">g</span>).<span class="ident">unwrap</span>(); <span class="ident">drop</span>(<span class="ident">g</span>); <span class="kw">let</span> <span class="ident">m</span> <span class="op">=</span> <span class="ident">Mutex</span>::<span class="ident">new</span>(()); <span class="kw">let</span> _ <span class="op">=</span> <span class="ident">c</span>.<span class="ident">wait</span>(<span class="ident">m</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>()).<span class="ident">unwrap</span>(); } } </pre> </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>?</dt> <dd>Show this help dialog</dd> <dt>S</dt> <dd>Focus the search field</dd> <dt>⇤</dt> <dd>Move up in search results</dd> <dt>⇥</dt> <dd>Move down in search results</dd> <dt>⏎</dt> <dd>Go to active search result</dd> <dt>+</dt> <dd>Collapse/expand 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 = "../../../"; 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