<!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/mpsc/blocking.rs`."> <meta name="keywords" content="rust, rustlang, rust-lang"> <title>blocking.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> <span id="30">30</span> <span id="31">31</span> <span id="32">32</span> <span id="33">33</span> <span id="34">34</span> <span id="35">35</span> <span id="36">36</span> <span id="37">37</span> <span id="38">38</span> <span id="39">39</span> <span id="40">40</span> <span id="41">41</span> <span id="42">42</span> <span id="43">43</span> <span id="44">44</span> <span id="45">45</span> <span id="46">46</span> <span id="47">47</span> <span id="48">48</span> <span id="49">49</span> <span id="50">50</span> <span id="51">51</span> <span id="52">52</span> <span id="53">53</span> <span id="54">54</span> <span id="55">55</span> <span id="56">56</span> <span id="57">57</span> <span id="58">58</span> <span id="59">59</span> <span id="60">60</span> <span id="61">61</span> <span id="62">62</span> <span id="63">63</span> <span id="64">64</span> <span id="65">65</span> <span id="66">66</span> <span id="67">67</span> <span id="68">68</span> <span id="69">69</span> <span id="70">70</span> <span id="71">71</span> <span id="72">72</span> <span id="73">73</span> <span id="74">74</span> <span id="75">75</span> <span id="76">76</span> <span id="77">77</span> <span id="78">78</span> <span id="79">79</span> <span id="80">80</span> <span id="81">81</span> <span id="82">82</span> <span id="83">83</span> <span id="84">84</span> <span id="85">85</span> <span id="86">86</span> <span id="87">87</span> <span id="88">88</span> <span id="89">89</span> <span id="90">90</span> <span id="91">91</span> <span id="92">92</span> <span id="93">93</span> <span id="94">94</span> <span id="95">95</span> <span id="96">96</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="doccomment">//! Generic support for building blocking abstractions.</span> <span class="kw">use</span> <span class="ident">thread</span>::{<span class="self">self</span>, <span class="ident">Thread</span>}; <span class="kw">use</span> <span class="ident">sync</span>::<span class="ident">atomic</span>::{<span class="ident">AtomicBool</span>, <span class="ident">Ordering</span>}; <span class="kw">use</span> <span class="ident">sync</span>::<span class="ident">Arc</span>; <span class="kw">use</span> <span class="ident">mem</span>; <span class="kw">use</span> <span class="ident">time</span>::<span class="ident">Instant</span>; <span class="kw">struct</span> <span class="ident">Inner</span> { <span class="ident">thread</span>: <span class="ident">Thread</span>, <span class="ident">woken</span>: <span class="ident">AtomicBool</span>, } <span class="kw">unsafe</span> <span class="kw">impl</span> <span class="ident">Send</span> <span class="kw">for</span> <span class="ident">Inner</span> {} <span class="kw">unsafe</span> <span class="kw">impl</span> <span class="ident">Sync</span> <span class="kw">for</span> <span class="ident">Inner</span> {} <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>)]</span> <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">SignalToken</span> { <span class="ident">inner</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">Inner</span><span class="op">></span>, } <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">WaitToken</span> { <span class="ident">inner</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">Inner</span><span class="op">></span>, } <span class="kw">impl</span> <span class="op">!</span><span class="ident">Send</span> <span class="kw">for</span> <span class="ident">WaitToken</span> {} <span class="kw">impl</span> <span class="op">!</span><span class="ident">Sync</span> <span class="kw">for</span> <span class="ident">WaitToken</span> {} <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">tokens</span>() <span class="op">-></span> (<span class="ident">WaitToken</span>, <span class="ident">SignalToken</span>) { <span class="kw">let</span> <span class="ident">inner</span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">Inner</span> { <span class="ident">thread</span>: <span class="ident">thread</span>::<span class="ident">current</span>(), <span class="ident">woken</span>: <span class="ident">AtomicBool</span>::<span class="ident">new</span>(<span class="bool-val">false</span>), }); <span class="kw">let</span> <span class="ident">wait_token</span> <span class="op">=</span> <span class="ident">WaitToken</span> { <span class="ident">inner</span>: <span class="ident">inner</span>.<span class="ident">clone</span>(), }; <span class="kw">let</span> <span class="ident">signal_token</span> <span class="op">=</span> <span class="ident">SignalToken</span> { <span class="ident">inner</span>: <span class="ident">inner</span> }; (<span class="ident">wait_token</span>, <span class="ident">signal_token</span>) } <span class="kw">impl</span> <span class="ident">SignalToken</span> { <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">signal</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">bool</span> { <span class="kw">let</span> <span class="ident">wake</span> <span class="op">=</span> <span class="op">!</span><span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">woken</span>.<span class="ident">compare_and_swap</span>(<span class="bool-val">false</span>, <span class="bool-val">true</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>); <span class="kw">if</span> <span class="ident">wake</span> { <span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">thread</span>.<span class="ident">unpark</span>(); } <span class="ident">wake</span> } <span class="doccomment">/// Convert to an unsafe usize value. Useful for storing in a pipe's state</span> <span class="doccomment">/// flag.</span> <span class="attribute">#[<span class="ident">inline</span>]</span> <span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">cast_to_usize</span>(<span class="self">self</span>) <span class="op">-></span> <span class="ident">usize</span> { <span class="ident">mem</span>::<span class="ident">transmute</span>(<span class="self">self</span>.<span class="ident">inner</span>) } <span class="doccomment">/// Convert from an unsafe usize value. Useful for retrieving a pipe's state</span> <span class="doccomment">/// flag.</span> <span class="attribute">#[<span class="ident">inline</span>]</span> <span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">cast_from_usize</span>(<span class="ident">signal_ptr</span>: <span class="ident">usize</span>) <span class="op">-></span> <span class="ident">SignalToken</span> { <span class="ident">SignalToken</span> { <span class="ident">inner</span>: <span class="ident">mem</span>::<span class="ident">transmute</span>(<span class="ident">signal_ptr</span>) } } } <span class="kw">impl</span> <span class="ident">WaitToken</span> { <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait</span>(<span class="self">self</span>) { <span class="kw">while</span> <span class="op">!</span><span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">woken</span>.<span class="ident">load</span>(<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) { <span class="ident">thread</span>::<span class="ident">park</span>() } } <span class="doccomment">/// Returns true if we wake up normally, false otherwise.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_max_until</span>(<span class="self">self</span>, <span class="ident">end</span>: <span class="ident">Instant</span>) <span class="op">-></span> <span class="ident">bool</span> { <span class="kw">while</span> <span class="op">!</span><span class="self">self</span>.<span class="ident">inner</span>.<span class="ident">woken</span>.<span class="ident">load</span>(<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) { <span class="kw">let</span> <span class="ident">now</span> <span class="op">=</span> <span class="ident">Instant</span>::<span class="ident">now</span>(); <span class="kw">if</span> <span class="ident">now</span> <span class="op">>=</span> <span class="ident">end</span> { <span class="kw">return</span> <span class="bool-val">false</span>; } <span class="ident">thread</span>::<span class="ident">park_timeout</span>(<span class="ident">end</span> <span class="op">-</span> <span class="ident">now</span>) } <span class="bool-val">true</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 = "../../../../"; window.currentCrate = "std"; </script> <script src="../../../../main.js"></script> <script defer src="../../../../search-index.js"></script> </body> </html>