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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::atomic&lt;T&gt;::</span>is_lock_free</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-atomic.html">atomic</a>&lrm; | <a href="cpp-atomic-atomic.html">atomic</a></span></div>
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<td rowspan="142"><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></td>
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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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<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="kw4">volatile</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<p>&#26816;&#26597;&#27492;&#31867;&#22411;&#25152;&#26377;&#23545;&#35937;&#19978;&#30340;&#21407;&#23376;&#25805;&#20316;&#26159;&#21542;&#20813;&#38145;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<p>&#65288;&#26080;&#65289;</p>
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#33509;&#27492;&#31867;&#22411;&#25152;&#26377;&#23545;&#35937;&#19978;&#30340;&#21407;&#23376;&#25805;&#20316;&#20813;&#38145;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> &#65292;&#21542;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> &#12290;</p>
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">&#27880;&#24847;</span></h3>
<p><span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> &#20197;&#22806;&#30340;&#25152;&#26377;&#21407;&#23376;&#31867;&#22411;&#21487;&#29992;&#20114;&#26021;&#25110;&#20854;&#20182;&#38145;&#23450;&#25805;&#20316;&#23454;&#29616;&#65292;&#32780;&#19981;&#19968;&#23450;&#29992;&#20813;&#38145;&#30340;&#21407;&#23376; CPU &#25351;&#20196;&#12290;&#20134;&#20801;&#35768;&#21407;&#23376;&#31867;&#22411;<i>&#26377;&#26102;</i>&#20813;&#38145;&#65292;&#20363;&#22914;&#33509;&#32473;&#23450;&#26550;&#26500;&#19978;&#20165;&#23545;&#40784;&#30340;&#20869;&#23384;&#35775;&#38382;&#26159;&#22825;&#28982;&#21407;&#23376;&#30340;&#65292;&#21017;&#21516;&#31867;&#22411;&#30340;&#38169;&#35823;&#23545;&#40784;&#23545;&#35937;&#24517;&#39035;&#29992;&#38145;&#12290;</p>
<p>C++ &#26631;&#20934;&#25512;&#33616;&#65288;&#20294;&#19981;&#35201;&#27714;&#65289;&#20813;&#38145;&#25805;&#20316;&#20134;&#20026;&#20813;&#22320;&#22336;&#65292;&#21363;&#36866;&#29992;&#20110;&#20351;&#29992;&#20849;&#20139;&#20869;&#23384;&#30340;&#36827;&#31243;&#38388;&#20132;&#27969;&#12290;</p>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
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<pre class="de1"><span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;utility&gt;</span>
<span class="co2">#include &lt;atomic&gt;</span>
<span class="kw1">struct</span> A <span class="br0">{</span> <span class="kw4">int</span> a<span class="br0">[</span><span class="nu0">100</span><span class="br0">]</span><span class="sy4">;</span> <span class="br0">}</span><span class="sy4">;</span>
<span class="kw1">struct</span> B <span class="br0">{</span> <span class="kw4">int</span> x, y<span class="sy4">;</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>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <a href="cpp-io-manip-boolalpha.html"><span class="kw1764">std::<span class="me2">boolalpha</span></span></a>
<span class="sy1">&lt;&lt;</span> <span class="st0">&quot;std::atomic&lt;A&gt; is lock free? &quot;</span>
<span class="sy1">&lt;&lt;</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1">&lt;</span>A<span class="sy1">&gt;</span><span class="br0">{</span><span class="br0">}</span>.<span class="me1">is_lock_free</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span>
<span class="sy1">&lt;&lt;</span> <span class="st0">&quot;std::atomic&lt;B&gt; is lock free? &quot;</span>
<span class="sy1">&lt;&lt;</span> <a href="cpp-atomic-atomic.html"><span class="kw2066">std::<span class="me2">atomic</span></span></a><span class="sy1">&lt;</span>B<span class="sy1">&gt;</span><span class="br0">{</span><span class="br0">}</span>.<span class="me1">is_lock_free</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
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<p>&#21487;&#33021;&#30340;&#36755;&#20986;&#65306;</p>
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<pre class="de1">std::atomic&lt;A&gt; is lock free? false
std::atomic&lt;B&gt; is lock free? true</pre></div>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
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<div><a href="cpp-atomic-atomic_is_lock_free.html"><span class="t-lines"><span>atomic_is_lock_free</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
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<td>&#26816;&#26597;&#23545;&#35813;&#21407;&#23376;&#31867;&#22411;&#30340;&#25805;&#20316;&#26159;&#21542;&#26159;&#26080;&#38145;&#30340;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
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<div><a href="cpp-memory-shared_ptr-atomic.html"><span class="t-lines"><span>atomic_is_lock_free<span class="t-dsc-small">(std::shared_ptr)</span></span></span></a></div>
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<td>&#23545; <span class="t-lc"><a href="cpp-memory-shared_ptr.html">std::shared_ptr</a></span> &#29305;&#21270;&#21407;&#23376;&#25805;&#20316;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
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<div><a href="cpp-atomic-atomic-is_always_lock_free.html"><span class="t-lines"><span>is_always_lock_free</span></span></a></div>
<div><span class="t-lines"><span><span class="t-cmark">[&#38745;&#24577;]</span> <span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
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<td>&#25351;&#31034;&#35813;&#31867;&#22411;&#26159;&#21542;&#22987;&#32456;&#20813;&#38145;<br />
<span class="t-mark">(&#20844;&#24320;&#38745;&#24577;&#25104;&#21592;&#24120;&#37327;)</span></td>
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