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<article id="wikiArticle">
<p></p><p></p>
<p><strong><code>Atomics</code></strong> 对象提供了一组静态方法用来对 <a href="Reference/Global_Objects/SharedArrayBuffer" title="SharedArrayBuffer 对象用来表示一个通用的固定长度的原始二进制数据缓冲区类似于 ArrayBuffer 对象它们都可以用来在共享内存shared memory上创建视图。与 ArrayBuffer 不同的是SharedArrayBuffer 不能被分离。"><code>SharedArrayBuffer</code></a> 对象进行原子操作。</p>
<p>这些原子操作属于 <code>Atomics</code> 模块。与一般的全局对象不同,<code>Atomics</code> 不是构造函数,因此不能使用 <a href="https://developer.mozilla.orgReference/Operators/new">new</a> 操作符调用,也不能将其当作函数直接调用。<code>Atomics</code> 的所有属性和方法都是静态的(与 <a href="Reference/Global_Objects/Math" title="Math 是一个内置对象 它具有数学常数和函数的属性和方法。不是一个函数对象。"><code>Math</code></a>  对象一样)。</p>
<h2 id="属性">属性</h2>
<dl>
<dt><code>Atomics[Symbol.toStringTag]</code></dt>
<dd>该属性的值为“Atomics”。</dd>
</dl>
<h2 id="方法">方法</h2>
<h3 id="原子操作">原子操作</h3>
<p>多个共享内存的线程能够同时读写同一位置上的数据。原子操作会确保正在读或写的数据的值是符合预期的,即下一个原子操作一定会在上一个原子操作结束后才会开始,其操作过程不会中断。</p>
<dl>
<dt><span style="display: none;"> </span></dt>
<dt><a href="Reference/Global_Objects/Atomics/add" title="Atomics.add() 静态方法会将给定的值加到数组里的某个特定位置上,并返回该位置的旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.add()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相加,并返回相加前该元素的值。</dd>
<dt><strong><a href="Reference/Global_Objects/Atomics/and" title="Atomics.and() 静态方法会将给定的值与数组上的值进行按位与操作,并将结果赋值给数组,然后返回数组该位置上的旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.and()</code></a></strong></dt>
<dd>将指定位置上的数组元素与给定的值相与,并返回与操作前该元素的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/compareExchange" title="Atomics.compareExchange() 静态方法会在数组的值与期望值相等的时候,将给定的替换值替换掉数组上的值,然后返回旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.compareExchange()</code></a></dt>
<dd>如果数组中指定的元素与给定的值相等,则将其更新为新的值,并返回该元素原先的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/exchange" title="Atomics.exchange() 静态方法会用给定的值替换掉数组上的值,然后返回数组的旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.exchange()</code></a></dt>
<dd>将数组中指定的元素更新为给定的值,并返回该元素更新前的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/load" title="静态方法 Atomics.load() 返回一个数组当中给定位置的值。"><code>Atomics.load()</code></a></dt>
<dd>返回数组中指定元素的值。</dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/or" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.or()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相或,并返回或操作前该元素的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/store" title="静态的Atomics.store方法将给定的值存储在数组中的指定位置并返回该值。."><code>Atomics.store()</code></a></dt>
<dd>将数组中指定的元素设置为给定的值,并返回<strong>该值</strong></dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/sub" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.sub()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相减,并返回相减前该元素的值。</dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/xor" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.xor()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相异或,并返回异或操作前该元素的值。</dd>
</dl>
<h3 id="等待和唤醒">等待和唤醒</h3>
<p><code>wait()</code><code>wake()</code> 方法采用的是 Linux 上的 futexes 模型fast user-space mutex快速用户空间互斥量可以让进程一直等待直到某个特定的条件为真主要用于实现阻塞。</p>
<dl>
<dt><a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wait()</code></a></dt>
<dd>检测数组中某个指定位置上的值是否仍然是给定值,是则保持挂起直到被唤醒或超时。返回值为 "<code>ok</code>"、"<code>not-equal</code>" 或 "<code>time-out</code>"。调用时,如果当前线程不允许阻塞,则会抛出异常(大多数浏览器都不允许在主线程中调用 <code>wait()</code>)。</dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/wake" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wake()</code></a></dt>
<dd>唤醒等待队列中正在数组指定位置的元素上等待的线程。返回值为成功唤醒的线程数量。</dd>
<dt><a href="Reference/Global_Objects/Atomics/isLockFree" title="静态方法 Atomics.isLockFree() 用于校验是否能够使用原子操作的TypedArray的标准字节长度之一. 若该字节长度为可处理的TypedArray标准字节长度之一则返回  true.  TypedArray的标准字节长度参见 BYTES_PER_ELEMENT"><code>Atomics.isLockFree(size)</code></a></dt>
<dd>可以用来检测当前系统是否支持硬件级的原子操作。对于指定大小的数组,如果当前系统支持硬件级的原子操作,则返回 <code>true</code>;否则就意味着对于该数组,<code>Atomics</code> 对象中的各原子操作都只能用锁来实现。此函数面向的是技术专家。</dd>
</dl>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范</th>
<th scope="col">状态</th>
<th scope="col">说明</th>
</tr>
<tr>
<td><a class="external" href="https://tc39.github.io/ecma262/#sec-atomics-object" hreflang="en" lang="en" rel="noopener">ECMAScript Latest Draft (ECMA-262)<br/><small lang="zh-CN">Atomics</small></a></td>
<td><span class="spec-Draft">Draft</span></td>
<td>ES2017 中的初始定义</td>
</tr>
<tr>
<td><a class="external" href="https://www.ecma-international.org/ecma-262/8.0/#sec-atomics-object" hreflang="en" lang="en" rel="noopener">ECMAScript 2017 (ECMA-262)<br/><small lang="zh-CN">Atomics</small></a></td>
<td><span class="spec-Standard">Standard</span></td>
<td> </td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<div class="hidden">The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out <a class="external" href="https://github.com/mdn/browser-compat-data" rel="noopener">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</div>
<p></p><div class="bc-data"><a class="bc-github-link external" href="https://github.com/mdn/browser-compat-data" rel="noopener">Update compatibility data on GitHub</a><table class="bc-table bc-table-js"><thead><tr class="bc-platforms"><td></td><th class="bc-platform-desktop" colspan="6"><span>Desktop</span></th><th class="bc-platform-mobile" colspan="7"><span>Mobile</span></th><th class="bc-platform-server" colspan="1"><span>Server</span></th></tr><tr class="bc-browsers"><td></td><th class="bc-browser-chrome"><span class="bc-head-txt-label bc-head-icon-chrome">Chrome</span></th><th class="bc-browser-edge"><span class="bc-head-txt-label bc-head-icon-edge">Edge</span></th><th class="bc-browser-firefox"><span class="bc-head-txt-label bc-head-icon-firefox">Firefox</span></th><th class="bc-browser-ie"><span class="bc-head-txt-label bc-head-icon-ie">Internet Explorer</span></th><th class="bc-browser-opera"><span class="bc-head-txt-label bc-head-icon-opera">Opera</span></th><th class="bc-browser-safari"><span class="bc-head-txt-label bc-head-icon-safari">Safari</span></th><th class="bc-browser-webview_android"><span class="bc-head-txt-label bc-head-icon-webview_android">Android webview</span></th><th class="bc-browser-chrome_android"><span class="bc-head-txt-label bc-head-icon-chrome_android">Chrome for Android</span></th><th class="bc-browser-edge_mobile"><span class="bc-head-txt-label bc-head-icon-edge_mobile">Edge Mobile</span></th><th class="bc-browser-firefox_android"><span class="bc-head-txt-label bc-head-icon-firefox_android">Firefox for Android</span></th><th class="bc-browser-opera_android"><span class="bc-head-txt-label bc-head-icon-opera_android">Opera for Android</span></th><th class="bc-browser-safari_ios"><span class="bc-head-txt-label bc-head-icon-safari_ios">Safari on iOS</span></th><th class="bc-browser-samsunginternet_android"><span class="bc-head-txt-label bc-head-icon-samsunginternet_android">Samsung Internet</span></th><th class="bc-browser-nodejs"><span class="bc-head-txt-label bc-head-icon-nodejs">Node.js</span></th></tr></thead><tbody><tr><th scope="row"><code>Atomics</code></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect1"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect2"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect3"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect4"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect5"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect6"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/add"><code>add</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect7"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect8"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect9"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect10"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect11"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect12"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/and"><code>and</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect13"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect14"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect15"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect16"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect17"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect18"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/compareExchange"><code>compareExchange</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect19"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect20"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect21"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect22"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect23"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect24"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/exchange"><code>exchange</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect25"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect26"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect27"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect28"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect29"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect30"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/isLockFree"><code>isLockFree</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect31"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect32"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect33"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect34"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect35"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect36"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/load"><code>load</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect37"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect38"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect39"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect40"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect41"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect42"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/notify" rel="nofollow"><code>notify</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect43"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect44"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect45"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 63: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The <code>count</code> parameter defaults to <code>0</code> instead of the later-specified <code>+Infinity</code>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari bc-has-history"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect46"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect47"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect48"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect49"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 63: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The <code>count</code> parameter defaults to <code>0</code> instead of the later-specified <code>+Infinity</code>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs bc-has-history"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect50"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/or" rel="nofollow"><code>or</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect51"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect52"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect53"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect54"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect55"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect56"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/store"><code>store</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect57"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect58"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect59"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect60"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect61"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect62"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/sub" rel="nofollow"><code>sub</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect63"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect64"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect65"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect66"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect67"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect68"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow"><code>wait</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect69"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect70"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect71"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The method returns values <code>Atomics.OK</code>, <code>Atomics.TIMEDOUT</code>, and <code>Atomics.NOTEQUAL</code>, instead of the later-specified strings.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWait</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect72"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect73"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect74"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The method returns values <code>Atomics.OK</code>, <code>Atomics.TIMEDOUT</code>, and <code>Atomics.NOTEQUAL</code>, instead of the later-specified strings.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWait</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/xor" rel="nofollow"><code>xor</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div><section class="bc-history" id="sect75"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect76"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect77"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect78"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect79"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
?
</abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect80"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
8.10.0</td></tr></tbody></table><section class="bc-legend" id="sect81"><h3 class="offscreen" id="Legend">Legend</h3><dl><dt><span class="bc-supports-yes bc-supports">
<abbr class="bc-level bc-level-yes only-icon" title="Full support">
<span>Full support</span>
 
</abbr></span></dt><dd>Full support</dd><dt><span class="bc-supports-no bc-supports">
<abbr class="bc-level bc-level-no only-icon" title="No support">
<span>No support</span>
 
</abbr></span></dt><dd>No support</dd><dt><span class="bc-supports-unknown bc-supports">
<abbr class="bc-level bc-level-unknown only-icon" title="Compatibility unknown">
<span>Compatibility unknown</span>
 
</abbr></span></dt><dd>Compatibility unknown</dd><dt><abbr class="only-icon" title="See implementation notes."><span>See implementation notes.</span><i class="ic-footnote"></i></abbr></dt><dd>See implementation notes.</dd><dt><abbr class="only-icon" title="User must explicitly enable this feature."><span>User must explicitly enable this feature.</span><i class="ic-disabled"></i></abbr></dt><dd>User must explicitly enable this feature.</dd><dt><abbr class="only-icon" title="Uses a non-standard name."><span>Uses a non-standard name.</span><i class="ic-altname"></i></abbr></dt><dd>Uses a non-standard name.</dd></dl></section></div><p></p>
<h2 id="兼容性提示">兼容性提示</h2>
<p>直到 Firefox 48最新的 API 名称和语意都还没有实现。FirFox 46 到 FireFox 48 之间主要有以下变化:</p>
<ul>
<li>移除了方法 <code>Atomics.futexWakeOrRequeue()</code> 和 <code>Atomics.fence()</code> bug(1259544)、bug(1225028))。</li>
<li> <a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wait()</code></a> 和 <a class="new" href="Reference/Global_Objects/Atomics/wake" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wake()</code></a> 方法名称已改为 <code>Atomics.futexWait()</code> 和 <code>Atomics.futexWake()</code><a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1260910" rel="noopener" title="FIXED: Rename Atomics.{futexWait,futexWake} as Atomics.{wait,wake}">bug 1260910</a>)。注意:之前的名称在 49 版本之后已被移除(<a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1262062" rel="noopener" title="FIXED: Remove futexWait and futexWake aliases after FF48 branches">bug 1262062</a></li>
<li>移除了属性 <code>Atomics.OK</code>、 <code>Atomics.TIMEDOUT</code>、 <code>Atomics.NOTEQUAL</code><a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wait()</code></a> 方法现在返回字符串 "ok"、"timed-out" 和 "not-equal" <a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1260835" rel="noopener" title="FIXED: Remove Atomics.{OK,NOTEQUAL,TIMEDOUT}, return strings from Atomics.futexWait instead">bug 1260835</a>)。</li>
<li>
<p><a class="new" href="Reference/Global_Objects/Atomics/wake" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wake()</code></a> 方法的 <code>count</code> 参数的默认值从 <code>0</code> 变为 <code>+Infinity</code><a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1253350" rel="noopener" title='FIXED: Shared memory spec change: futexWake / futexWakeOrRequeue "count" argument'>bug 1253350</a>)。</p>
</li>
</ul>
<h2 id="相关链接">相关链接</h2>
<ul>
<li><a href="Reference/Global_Objects/ArrayBuffer" title="The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request."><code>ArrayBuffer</code></a></li>
<li><a href="Typed_arrays">JavaScript typed arrays</a></li>
<li><a href="/zh-CN/docs/Web/API/Web_Workers_API">Web Workers</a></li>
<li><a class="external" href="https://github.com/lars-t-hansen/parlib-simple" rel="noopener">parlib-simple </a> a simple library providing synchronization and work distribution abstractions.</li>
<li><a class="external" href="https://github.com/tc39/ecmascript_sharedmem/blob/master/TUTORIAL.md" rel="noopener">Shared Memory a brief tutorial</a></li>
<li><a class="external" href="https://hacks.mozilla.org/2016/05/a-taste-of-javascripts-new-parallel-primitives/" rel="noopener">A Taste of JavaScripts New Parallel Primitives Mozilla Hacks</a></li>
</ul>
</article>