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<title>std::atomic_compare_exchange_weak, std::atomic_compare_exchange_strong, std::atomic_compare_exchange_weak_explicit, std::atomic_compare_exchange_strong_explicit</title>
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>atomic_compare_exchange_weak, <span style="font-size:0.7em; line-height:130%">std::</span>atomic_compare_exchange_strong, <span style="font-size:0.7em; line-height:130%">std::</span>atomic_compare_exchange_weak_explicit, <span style="font-size:0.7em; line-height:130%">std::</span>atomic_compare_exchange_strong_explicit</h1>
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-atomic.html">atomic</a></span></div>
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<div>定义于头文件 <code><a href="cpp-header-atomic.html"><atomic></a></code></div>
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<td rowspan="142">(1)</td>
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<td rowspan="142"><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_weak<span class="br0">(</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br /></p>
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_weak<span class="br0">(</span> <span class="kw4">volatile</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br /></p>
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<td rowspan="142">(2)</td>
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<td rowspan="142"><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_strong<span class="br0">(</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br /></p>
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_strong<span class="br0">(</span> <span class="kw4">volatile</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br /></p>
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<td rowspan="142">(3)</td>
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<td rowspan="142"><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_weak_explicit<span class="br0">(</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired,<br />
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> succ,<br /></p>
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> fail <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_weak_explicit<span class="br0">(</span> <span class="kw4">volatile</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired,<br />
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> succ,<br /></p>
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> fail <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<tbody class="t-dcl-rev t-dcl-rev-num t-dcl-rev-notes t-since-cxx11">
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<td rowspan="142">(4)</td>
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<td rowspan="142"><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_strong_explicit<span class="br0">(</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired,<br />
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> succ,<br /></p>
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> fail <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br /></span>
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<p><span class="kw4">bool</span> atomic_compare_exchange_strong_explicit<span class="br0">(</span> <span class="kw4">volatile</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> obj,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span><span class="sy2">*</span> expected,<br />
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<span class="kw1">typename</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">value_type</span> desired,<br />
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> succ,<br /></p>
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<a href="cpp-atomic-memory_order.html"><span class="kw2088">std::<span class="me2">memory_order</span></span></a> fail <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
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<p>原子地比较 <code>obj</code> 所指向对象与 <code>expected</code> 所指向对象的<span class="t-rev-inl t-until-cxx20"><span><a href="cpp-language-object.html">对象表示</a></span> <span><span class="t-mark-rev t-until-cxx20">(C++20 前)</span></span></span><span class="t-rev-inl t-since-cxx20"><span><a href="cpp-language-object.html">值表示</a></span> <span><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></span></span>，而若它们逐位相等，则以 <code>desired</code> 替换前者（进行读修改写操作）。否则，将 <code>obj</code> 所指向对象的实际值加载到 <code>*expected</code> （进行加载操作）。复制如同以 <span class="t-lc"><a href="cpp-string-byte-memcpy.html">std::memcpy</a></span> 进行。</p>
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<p>读-修改-写和加载操作的内存模型各为 <code>succ</code> 和 <code>fail</code> 。 (1-2) 版本默认使用 <span class="t-lc"><a href="cpp-atomic-memory_order.html">std::memory_order_seq_cst</a></span> 。</p>
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<p>这些函数用 <span class="t-lc"><a href="cpp-atomic-atomic.html">std::atomic</a></span> 的成员函数定义：</p>
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<div class="t-li1"><span class="t-li">1)</span> <span class="t-c"><span class="mw-geshi cpp source-cpp">obj<span class="sy2">-</span><span class="sy1">></span>compare_exchange_weak<span class="br0">(</span><span class="sy2">*</span>expected, desired<span class="br0">)</span></span></span></div>
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<div class="t-li1"><span class="t-li">2)</span> <span class="t-c"><span class="mw-geshi cpp source-cpp">obj<span class="sy2">-</span><span class="sy1">></span>compare_exchange_strong<span class="br0">(</span><span class="sy2">*</span>expected, desired<span class="br0">)</span></span></span></div>
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<div class="t-li1"><span class="t-li">3)</span> <span class="t-c"><span class="mw-geshi cpp source-cpp">obj<span class="sy2">-</span><span class="sy1">></span>compare_exchange_weak<span class="br0">(</span><span class="sy2">*</span>expected, desired, succ, fail<span class="br0">)</span></span></span></div>
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<div class="t-li1"><span class="t-li">4)</span> <span class="t-c"><span class="mw-geshi cpp source-cpp">obj<span class="sy2">-</span><span class="sy1">></span>compare_exchange_strong<span class="br0">(</span><span class="sy2">*</span>expected, desired, succ, fail<span class="br0">)</span></span></span></div>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
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<table class="t-par-begin">
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<tr class="t-par">
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<td>obj</td>
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<td>-</td>
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<td>指向要测试和修改的原子对象的指针</td>
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</tr>
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<tr class="t-par">
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<td>expected</td>
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<td>-</td>
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<td>指向期待在原子对象中找到的值的指针</td>
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</tr>
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<tr class="t-par">
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<td>desired</td>
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<td>-</td>
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<td>若满足期待，则要存储于原子对象的值</td>
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</tr>
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<tr class="t-par">
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<td>succ</td>
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<td>-</td>
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<td>若比较成功则用于读-修改-写操作的内存同步顺序。容许所有值。</td>
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</tr>
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<tr class="t-par">
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<td>fail</td>
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<td>-</td>
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<td>若比较失败则用于加载操作的内存同步顺序。不能是 <span class="t-lc"><a href="cpp-atomic-memory_order.html">std::memory_order_release</a></span> 或 <span class="t-lc"><a href="cpp-atomic-memory_order.html">std::memory_order_acq_rel</a></span> <span class="t-rev-inl t-until-cxx17"><span>且不能指定强于 <code>succ</code> 的顺序</span> <span><span class="t-mark-rev t-until-cxx17">(C++17 前)</span></span></span></td>
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</tr>
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</table>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
||||
<p>比较结果：若 <code>*obj</code> 等于 <code>*expected</code> 则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> ，否则 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> 。</p>
|
||||
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
||||
<p>函数的弱形式（ (1) 与 (3) ）允许虚假地失败，即表现为如同 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span>obj <span class="sy3">!</span><span class="sy1">=</span> <span class="sy2">*</span>expected</span></span> ，即使它们相等。当比较并交换在循环中时，弱版本在某些平台上会生成更好的性能。</p>
|
||||
<p>在弱版本会要求循环而强版本不要求时，更偏好强版本，除非 <code>T</code> 的对象表示可能包含<span class="t-rev-inl t-until-cxx20"><span>t填充位、</span> <span><span class="t-mark-rev t-until-cxx20">(C++20 前)</span></span></span>陷阱位，或者为一个值提供多个对象表示（例如浮点 NaN ）。这些情况下，弱的比较并交换经常有用，因为它在某些稳定对象表示上快速收敛。</p>
|
||||
<p>若有些位参与 union 某些成员，但非其他成员的值表示，则比较和交换可能始终失败，因为这种填充位在不参与活跃成员的值表示时拥有不确定值。</p>
|
||||
<table class="t-rev-begin">
|
||||
<tr class="t-rev t-since-cxx20">
|
||||
<td>
|
||||
<p>忽略决不参与对象值表示的填充位。</p>
|
||||
</td>
|
||||
<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
|
||||
</tr>
|
||||
</table>
|
||||
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
||||
<div class="t-example">
|
||||
<p>比较并交换操作常用作无锁数据结构的基础构建块</p>
|
||||
<div class="t-example-live-link"></div>
|
||||
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
||||
<div class="cpp source-cpp">
|
||||
<pre class="de1"><span class="co2">#include <atomic></span>
|
||||
|
||||
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T<span class="sy1">></span>
|
||||
<span class="kw1">struct</span> node
|
||||
<span class="br0">{</span>
|
||||
T data<span class="sy4">;</span>
|
||||
node<span class="sy2">*</span> next<span class="sy4">;</span>
|
||||
node<span class="br0">(</span><span class="kw4">const</span> T<span class="sy3">&</span> data<span class="br0">)</span> <span class="sy4">:</span> data<span class="br0">(</span>data<span class="br0">)</span>, next<span class="br0">(</span>nullptr<span class="br0">)</span> <span class="br0">{</span><span class="br0">}</span>
|
||||
<span class="br0">}</span><span class="sy4">;</span>
|
||||
|
||||
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T<span class="sy1">></span>
|
||||
<span class="kw1">class</span> stack
|
||||
<span class="br0">{</span>
|
||||
<a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1"><</span>node<span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span><span class="sy1">></span> head<span class="sy4">;</span>
|
||||
<span class="kw1">public</span><span class="sy4">:</span>
|
||||
<span class="kw4">void</span> push<span class="br0">(</span><span class="kw4">const</span> T<span class="sy3">&</span> data<span class="br0">)</span>
|
||||
<span class="br0">{</span>
|
||||
node<span class="sy1"><</span>T<span class="sy1">></span><span class="sy2">*</span> new_node <span class="sy1">=</span> new node<span class="sy1"><</span>T<span class="sy1">></span><span class="br0">(</span>data<span class="br0">)</span><span class="sy4">;</span>
|
||||
|
||||
<span class="co1">// 将 head 的当前值放入 new_node->next</span>
|
||||
new_node<span class="sy2">-</span><span class="sy1">></span>next <span class="sy1">=</span> head.<span class="me1">load</span><span class="br0">(</span><a href="cpp-atomic-memory_order.html"><span class="kw2089">std::<span class="me2">memory_order_relaxed</span></span></a><span class="br0">)</span><span class="sy4">;</span>
|
||||
|
||||
<span class="co1">// 现在令 new_node 为新的 head ，</span>
|
||||
<span class="co1">// 但若 head 不再是存储于 new_node->next 者</span>
|
||||
<span class="co1">// （某些其他线程必须已在现在插入结点）</span>
|
||||
<span class="co1">// 则将新的 head 放入 new_node->next 并重试</span>
|
||||
<span class="kw1">while</span><span class="br0">(</span><span class="sy3">!</span>std<span class="sy4">::</span><span class="me2">atomic_compare_exchange_weak_explicit</span><span class="br0">(</span>
|
||||
<span class="sy3">&</span>head,
|
||||
<span class="sy3">&</span>new_node<span class="sy2">-</span><span class="sy1">></span>next,
|
||||
new_node,
|
||||
<a href="cpp-atomic-memory_order.html"><span class="kw2092">std::<span class="me2">memory_order_release</span></span></a>,
|
||||
<a href="cpp-atomic-memory_order.html"><span class="kw2089">std::<span class="me2">memory_order_relaxed</span></span></a><span class="br0">)</span><span class="br0">)</span>
|
||||
<span class="sy4">;</span> <span class="co1">// 循环体为空</span>
|
||||
<span class="co1">// 注意：上述循环非线程安全，至少在</span>
|
||||
<span class="co1">// 早于 4.8.3 的 GCC （ bug 60272 ），早于 2014-05-05 的 clang （ bug 18899）</span>
|
||||
<span class="co1">// 早于 2014-03-17 的 MSVC （ bug 819819 ）。变通方法见成员函数版本</span>
|
||||
<span class="br0">}</span>
|
||||
<span class="br0">}</span><span class="sy4">;</span>
|
||||
|
||||
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
|
||||
<span class="br0">{</span>
|
||||
stack<span class="sy1"><</span><span class="kw4">int</span><span class="sy1">></span> s<span class="sy4">;</span>
|
||||
s.<span class="me1">push</span><span class="br0">(</span><span class="nu0">1</span><span class="br0">)</span><span class="sy4">;</span>
|
||||
s.<span class="me1">push</span><span class="br0">(</span><span class="nu0">2</span><span class="br0">)</span><span class="sy4">;</span>
|
||||
s.<span class="me1">push</span><span class="br0">(</span><span class="nu0">3</span><span class="br0">)</span><span class="sy4">;</span>
|
||||
<span class="br0">}</span></pre></div>
|
||||
</div>
|
||||
</div>
|
||||
<h3><span class="mw-headline" id=".E7.BC.BA.E9.99.B7.E6.8A.A5.E5.91.8A">缺陷报告</span></h3>
|
||||
<p>下列更改行为的缺陷报告追溯地应用于以前出版的 C++ 标准。</p>
|
||||
<table class="dsctable" style="font-size:0.8em">
|
||||
<tr>
|
||||
<th>DR</th>
|
||||
<th>应用于</th>
|
||||
<th>出版时的行为</th>
|
||||
<th>正确行为</th>
|
||||
</tr>
|
||||
<tr>
|
||||
<td><a rel="nofollow" class="external text" href="https://wg21.link/P0558R1">P0558R1</a></td>
|
||||
<td>C++11</td>
|
||||
<td>曾要求准确类型匹配，因为从多个参数推导 <code>T</code></td>
|
||||
<td>仅从 <code>atomic</code> 参数推导 <code>T</code></td>
|
||||
</tr>
|
||||
</table>
|
||||
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
||||
<table class="t-dsc-begin">
|
||||
<tr class="t-dsc">
|
||||
<td>
|
||||
<div class="t-dsc-member-div">
|
||||
<div><a href="cpp-atomic-atomic-compare_exchange.html"><span class="t-lines"><span>compare_exchange_weak</span><span>compare_exchange_strong</span></span></a></div>
|
||||
</div>
|
||||
</td>
|
||||
<td>原子地比较原子对象与非原子参数的值，若相等则进行交换，若不相等则进行加载<br />
|
||||
<span class="t-mark">(<code>std::atomic<T></code> 的公开成员函数)</span></td>
|
||||
</tr>
|
||||
<tr class="t-dsc">
|
||||
<td>
|
||||
<div class="t-dsc-member-div">
|
||||
<div><a href="cpp-atomic-atomic_exchange.html"><span class="t-lines"><span>atomic_exchange</span><span>atomic_exchange_explicit</span></span></a></div>
|
||||
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
|
||||
</div>
|
||||
</td>
|
||||
<td>原子地以非原子实参的值替换原子对象的值，并返回该原子对象的旧值<br />
|
||||
<span class="t-mark">(函数模板)</span></td>
|
||||
</tr>
|
||||
</table>
|
||||
<table class="t-dsc-begin">
|
||||
<tr class="t-dsc">
|
||||
<td>
|
||||
<div class="t-dsc-member-div">
|
||||
<div><a href="cpp-memory-shared_ptr-atomic.html"><span class="t-lines"><span>std::atomic_compare_exchange_weak<span class="t-dsc-small">(std::shared_ptr)</span></span> <span>std::atomic_compare_exchange_strong<span class="t-dsc-small">(std::shared_ptr)</span></span></span></a></div>
|
||||
<div><span class="t-lines"><span><span class="t-mark-rev t-deprecated-cxx20">(C++20 中弃用)</span></span></span></div>
|
||||
</div>
|
||||
</td>
|
||||
<td>为 std::shared_ptr 特化原子操作<br />
|
||||
<span class="t-mark">(函数模板)</span></td>
|
||||
</tr>
|
||||
</table>
|
||||
</div>
|
||||
<div class="visualClear"></div>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
Reference in New Issue
Block a user