215 lines
13 KiB
HTML
215 lines
13 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
|
|
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<title>std::jthread</title>
|
|
<link rel="stylesheet" href="ext.css" />
|
|
<link rel="stylesheet" href="site_modules.css" />
|
|
</head>
|
|
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_thread_jthread skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>jthread</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-thread.html">thread</a></span></div>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dsc-header">
|
|
<td>
|
|
<div>定义于头文件 <code><a href="cpp-header-thread.html"><thread></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx20">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">class</span> jthread<span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>类 <code>jthread</code> 表示<a href="https://en.wikipedia.org/wiki/Thread_(computing)" class="extiw" title="enwiki:Thread (computing)">单个执行线程</a>。它拥有通常同 <span class="t-lc"><a href="cpp-thread-thread.html">std::thread</a></span> 的行为，除了 <code>jthread</code> 在析构时自动再结合，而且能在具体情况下取消/停止。</p>
|
|
<p>线程在构造关联的线程对象时（在任何操作系统调度延迟后）立即开始执行，始于作为<a href="cpp-thread-jthread-jthread.html">构造函数参数</a>提供的顶层函数。忽略顶层函数的返回值，而若它因抛异常退出，则调用 <span class="t-lc"><a href="cpp-error-terminate.html">std::terminate</a></span> 。顶层函数可经由 <span class="t-lc"><a href="cpp-thread-promise.html">std::promise</a></span> 向调用方交流其返回值或异常，或通过修改共享变量（要求同步，见 <span class="t-lc"><a href="cpp-thread-mutex.html">std::mutex</a></span> 与 <span class="t-lc"><a href="cpp-atomic-atomic.html">std::atomic</a></span> ）。</p>
|
|
<p>不同于 <span class="t-lc"><a href="cpp-thread-thread.html">std::thread</a></span> ， <code>jthread</code> 逻辑上保有一个内部的 <code>std::stop_source</code> 类型私有成员，它维持共享停止状态。 <code>jthread</code> 的构造函数接受一个 <span class="t-lc">std::stop_token</span> 作为其首参数， <code>jthread</code> 将从其内部的 <code>stop_source</code> 传递它。这允许函数在其执行中检查是否已请求停止，而若已请求则返回。</p>
|
|
<p><code>std::jthread</code> 对象亦可在不表示任何线程的状态（在默认构造、被移动、 <span class="t-lc">detach</span> 或 <span class="t-lc">join</span> 后），而执行线程可以与任何 <code>jthread</code> 对象关联（ <span class="t-lc">detach</span> 后）。</p>
|
|
<p>没有二个 <code>std::jthread</code> 对象可表示同一执行线程； <code>std::jthread</code> 非<a href="cpp-named_req-CopyConstructible.html"><span style="font-style:italic">可复制构造</span> <span style="font-family: Georgia, 'DejaVu Serif', serif; font-style:italic">(CopyConstructible)</span></a> 或<a href="cpp-named_req-CopyAssignable.html"><span style="font-style:italic">可复制赋值</span> <span style="font-family: Georgia, 'DejaVu Serif', serif; font-style:italic">(CopyAssignable)</span></a> ，尽管它为<a href="cpp-named_req-MoveConstructible.html"><span style="font-style:italic">可移动构造</span> <span style="font-family: Georgia, 'DejaVu Serif', serif; font-style:italic">(MoveConstructible)</span></a> 及<a href="cpp-named_req-MoveAssignable.html"><span style="font-style:italic">可移动赋值</span> <span style="font-family: Georgia, 'DejaVu Serif', serif; font-style:italic">(MoveAssignable)</span></a> 。</p>
|
|
<h3><span class="mw-headline" id=".E6.88.90.E5.91.98.E7.B1.BB.E5.9E.8B">成员类型</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc-hitem">
|
|
<td>成员类型</td>
|
|
<td>定义</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>id</code></td>
|
|
<td><a href="cpp-thread-thread-id.html"><tt>std::thread::id</tt></a></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>native_handle_type</code> <span class="t-mark">(可选)</span></td>
|
|
<td><a href="cpp-thread-thread.html"><tt>std::thread::native_handle_type</tt></a></td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E6.88.90.E5.91.98.E5.87.BD.E6.95.B0">成员函数</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div t-dsc-member-nobold-div">
|
|
<div><a href="cpp-thread-jthread-jthread.html"><span class="t-lines"><span>(构造函数)</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>创建新的 <code>jthread</code> 对象<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div t-dsc-member-nobold-div">
|
|
<div><a href="cpp-thread-jthread-~jthread.html"><span class="t-lines"><span>(析构函数)</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>若 <code>joinable()</code> 为 <code>true</code> ，则调用 <code>request_stop()</code> 然后 <code>join()</code> ；不论如何都会销毁 <code>jthread</code> 对象。<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-operator=.html"><span class="t-lines"><span>operator=</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>移动 <code>jthread</code> 对象<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr>
|
|
<td colspan="2">
|
|
<h5><span class="mw-headline" id=".E8.A7.82.E5.AF.9F.E5.99.A8">观察器</span></h5>
|
|
</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-joinable.html"><span class="t-lines"><span>joinable</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>检查线程是否可合并，即潜在地运行于平行环境中<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-get_id.html"><span class="t-lines"><span>get_id</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>返回线程的 <i>id</i><br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-native_handle.html"><span class="t-lines"><span>native_handle</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>返回底层实现定义的线程句柄<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-hardware_concurrency.html"><span class="t-lines"><span>hardware_concurrency</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-cmark">[静态]</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>返回实现支持的并发线程数<br />
|
|
<span class="t-mark">(公开静态成员函数)</span></td>
|
|
</tr>
|
|
<tr>
|
|
<td colspan="2">
|
|
<h5><span class="mw-headline" id=".E6.93.8D.E4.BD.9C">操作</span></h5>
|
|
</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-join.html"><span class="t-lines"><span>join</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>等待线程完成其执行<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-detach.html"><span class="t-lines"><span>detach</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>容许线程从线程句柄独立开来执行<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-swap.html"><span class="t-lines"><span>swap</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>交换二个 <code>jthread</code> 对象<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr>
|
|
<td colspan="2">
|
|
<h5><span class="mw-headline" id=".E5.81.9C.E6.AD.A2.E8.AE.B0.E5.8F.B7.E5.A4.84.E7.90.86">停止记号处理</span></h5>
|
|
</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-get_stop_source.html"><span class="t-lines"><span>get_stop_source</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>返回与线程的停止状态关联的 <code>stop_source</code> 对象<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-get_stop_token.html"><span class="t-lines"><span>get_stop_token</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>返回与线程的共享停止状态关联的 <code>stop_token</code><br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-request_stop.html"><span class="t-lines"><span>request_stop</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>请求执行经由线程的共享停止状态停止<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E9.9D.9E.E6.88.90.E5.91.98.E5.87.BD.E6.95.B0">非成员函数</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-thread-jthread-swap2.html"><span class="t-lines"><span>swap<span class="t-dsc-small">(std::jthread)</span></span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx20">(C++20)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>特化 <span class="t-lc"><a href="cpp-algorithm-swap.html">std::swap</a></span> 算法<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|