68 lines
4.4 KiB
HTML
68 lines
4.4 KiB
HTML
<!DOCTYPE html>
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<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
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<title>std::atomic_ref<T>::is_lock_free</title>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_atomic_atomic_ref_is_lock_free skin-cppreference2 action-view cpp-navbar">
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<div id="cpp-content-base">
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<div id="content"><a id="top"></a>
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::atomic_ref<T>::</span>is_lock_free</h1>
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<div id="bodyContent">
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-atomic.html">atomic</a>‎ | <a href="cpp-atomic-atomic_ref.html">atomic ref</a></span></div>
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<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> is_lock_free<span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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</td>
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<td class="t-dcl-nopad"></td>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
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<td></td>
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<p>检查此对象上的原子操作是否免锁。</p>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
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<p>（无）</p>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
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<p>若此对象上的原子操作为免锁则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> ，否则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> 。</p>
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<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">注解</span></h3>
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<p><span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> 以外的所有原子类型可能会被用互斥或其他锁定操作实现，而不一定用免锁的原子 CPU 指令。亦允许原子类型<i>有时</i>免锁，例如若给定架构上仅对齐的内存访问是原生原子的，则同类型的错误对齐对象必须用锁。</p>
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<p>C++ 标准推荐（但不要求）免锁操作亦为免地址，即适用于使用共享内存的进程间交流。</p>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
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<td class="mbox-text" style="">本节未完成<br />
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原因：暂无示例</td>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
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<div class="t-dsc-member-div">
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<div><a href="cpp-atomic-atomic_ref-is_always_lock_free.html"><span class="t-lines"><span>is_always_lock_free</span></span></a></div>
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<div><span class="t-lines"><span><span class="t-cmark">[静态]</span></span></span></div>
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</div>
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</td>
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<td>指示该类型为始终免锁<br />
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<span class="t-mark">(公开静态成员常量)</span></td>
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