{"id":3839,"date":"2025-07-12T12:41:46","date_gmt":"2025-07-12T04:41:46","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3839"},"modified":"2025-07-12T12:42:39","modified_gmt":"2025-07-12T04:42:39","slug":"%e8%b0%88%e8%b0%88%e4%bd%a0%e5%af%b9aqs%e7%9a%84%e7%90%86%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/07\/12\/%e8%b0%88%e8%b0%88%e4%bd%a0%e5%af%b9aqs%e7%9a%84%e7%90%86%e8%a7%a3\/","title":{"rendered":"\u8c08\u8c08\u4f60\u5bf9AQS\u7684\u7406\u89e3"},"content":{"rendered":"\n<p>AbstractQueuedSynchronizer\uff08\u7b80\u79f0 <strong>AQS<\/strong>\uff09\u662f Java \u5e76\u53d1\u5305 <code>java.util.concurrent<\/code> \u7684\u6838\u5fc3\u57fa\u7840\u7ec4\u4ef6\u4e4b\u4e00\uff0c\u5c24\u5176\u662f\u6784\u5efa\u81ea\u5b9a\u4e49\u540c\u6b65\u5668\uff08\u5982\u9501\u3001\u4fe1\u53f7\u91cf\u3001\u6805\u680f\u7b49\uff09\u7684\u57fa\u7840\u6846\u67b6\u3002<strong>\u7406\u89e3 AQS \u662f\u6df1\u5165\u638c\u63e1 Java \u5e76\u53d1\u7f16\u7a0b\u7684\u5173\u952e\u6b65\u9aa4\u4e4b\u4e00\u3002<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e00\u3001AQS \u662f\u4ec0\u4e48\uff1f<\/h2>\n\n\n\n<p><strong>AQS \u5168\u79f0\uff1a<code>AbstractQueuedSynchronizer<\/code><\/strong><br>\u662f Java \u5e76\u53d1\u5305\u4e2d\u5b9a\u4e49\u7684\u4e00\u4e2a<strong>\u7528\u4e8e\u6784\u5efa\u9501\u548c\u540c\u6b65\u5668\u7684\u57fa\u7840\u6846\u67b6\u7c7b<\/strong>\uff0c\u5176\u6838\u5fc3\u539f\u7406\u662f\uff1a<strong>\u4ee5\u4e00\u4e2a int \u72b6\u6001\u503c\uff08state\uff09\u548c\u4e00\u4e2a FIFO \u53cc\u5411\u7b49\u5f85\u961f\u5217\u4e3a\u57fa\u7840<\/strong>\uff0c\u6765\u63a7\u5236\u7ebf\u7a0b\u7684\u5e76\u53d1\u8bbf\u95ee\u3002<\/p>\n\n\n\n<p>AQS \u4e3b\u8981\u901a\u8fc7**\u201c\u72b6\u6001\u4f4d + \u961f\u5217\u201d<strong>\u5b9e\u73b0<\/strong>\u7ebf\u7a0b\u4e4b\u95f4\u7684\u540c\u6b65\u4e0e\u901a\u4fe1**\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e8c\u3001\u6838\u5fc3\u7ed3\u6784\u4e0e\u5173\u952e\u70b9<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7ec4\u6210\u90e8\u5206<\/th><th>\u63cf\u8ff0<\/th><\/tr><\/thead><tbody><tr><td><code>state<\/code><\/td><td>\u8868\u793a\u540c\u6b65\u72b6\u6001\uff08\u4f8b\u5982\u662f\u5426\u5df2\u52a0\u9501\uff09<\/td><\/tr><tr><td><code>exclusive owner thread<\/code><\/td><td>\u72ec\u5360\u6a21\u5f0f\u4e0b\u8bb0\u5f55\u5f53\u524d\u6301\u6709\u9501\u7684\u7ebf\u7a0b<\/td><\/tr><tr><td><code>CLH \u961f\u5217<\/code><\/td><td>FIFO \u7b49\u5f85\u961f\u5217\uff0c\u4fdd\u5b58\u83b7\u53d6\u540c\u6b65\u72b6\u6001\u5931\u8d25\u7684\u7ebf\u7a0b<\/td><\/tr><tr><td><code>Node<\/code><\/td><td>\u961f\u5217\u4e2d\u7684\u5143\u7d20\uff0c\u6bcf\u4e2a\u7b49\u5f85\u7ebf\u7a0b\u5bf9\u5e94\u4e00\u4e2a Node \u8282\u70b9<\/td><\/tr><tr><td><code>compareAndSetState<\/code><\/td><td>\u4f7f\u7528 CAS \u539f\u5b50\u64cd\u4f5c\u4fdd\u8bc1\u7ebf\u7a0b\u5b89\u5168<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">AQS \u652f\u6301\u4e24\u79cd\u540c\u6b65\u6a21\u5f0f\uff1a<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u6a21\u5f0f<\/th><th>\u63cf\u8ff0<\/th><th>\u793a\u4f8b<\/th><\/tr><\/thead><tbody><tr><td>\u72ec\u5360\uff08Exclusive\uff09<\/td><td>\u540c\u4e00\u65f6\u95f4\u53ea\u5141\u8bb8\u4e00\u4e2a\u7ebf\u7a0b\u83b7\u53d6\u8d44\u6e90<\/td><td>ReentrantLock<\/td><\/tr><tr><td>\u5171\u4eab\uff08Shared\uff09<\/td><td>\u540c\u4e00\u8d44\u6e90\u53ef\u88ab\u591a\u4e2a\u7ebf\u7a0b\u5171\u4eab<\/td><td>CountDownLatch\u3001Semaphore<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e09\u3001\u5de5\u4f5c\u673a\u5236\u539f\u7406\uff08\u72ec\u5360\u6a21\u5f0f\uff09<\/h2>\n\n\n\n<p>\u4ee5 <strong>ReentrantLock\uff08\u72ec\u5360\uff09<\/strong> \u4e3a\u4f8b\uff0c\u7b80\u5316\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u7ebf\u7a0b\u5c1d\u8bd5\u901a\u8fc7 <code>tryAcquire()<\/code> \u83b7\u53d6\u9501<\/li>\n\n\n\n<li>\u5982\u679c\u83b7\u53d6\u5931\u8d25\uff08\u5373 state != 0\uff09\uff0c\u5219\u6784\u9020 <code>Node<\/code> \u8282\u70b9\u52a0\u5165 AQS \u7684\u7b49\u5f85\u961f\u5217<\/li>\n\n\n\n<li>\u540e\u7eed\u7ebf\u7a0b\u901a\u8fc7 <code>acquire()<\/code> \u4e0d\u65ad\u5c1d\u8bd5\u83b7\u53d6\u9501<\/li>\n\n\n\n<li>\u5f53\u524d\u7ebf\u7a0b\u91ca\u653e\u9501\u65f6\u8c03\u7528 <code>release()<\/code>\uff0c\u5e76\u901a\u77e5\uff08unpark\uff09\u4e0b\u4e00\u4e2a\u7b49\u5f85\u7ebf\u7a0b\u5c1d\u8bd5\u83b7\u53d6\u9501<\/li>\n<\/ol>\n\n\n\n<p>\ud83d\udccc AQS \u4e0d\u76f4\u63a5\u5b9e\u73b0\u540c\u6b65\u5668\u903b\u8f91\uff0c\u800c\u662f\u901a\u8fc7 <strong>\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f<\/strong>\uff0c\u5b50\u7c7b\uff08\u5982 <code>ReentrantLock<\/code>\uff09\u9700\u5b9e\u73b0\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>protected boolean tryAcquire(int arg);\nprotected boolean tryRelease(int arg);<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u56db\u3001\u6838\u5fc3\u65b9\u6cd5\u89e3\u6790\uff08\u6838\u5fc3\u9aa8\u67b6\uff09<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1\u3001\u72ec\u5360\u6a21\u5f0f\u6838\u5fc3\u65b9\u6cd5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public final void acquire(int arg)\npublic final boolean release(int arg)<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>acquire()<\/code>\uff1a\u5c1d\u8bd5\u83b7\u53d6\u9501\uff08\u5931\u8d25\u5219\u5165\u961f\uff09<\/li>\n\n\n\n<li><code>release()<\/code>\uff1a\u91ca\u653e\u9501\u5e76\u5524\u9192\u4e0b\u4e00\u4e2a\u8282\u70b9<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2\u3001\u5171\u4eab\u6a21\u5f0f\u6838\u5fc3\u65b9\u6cd5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public final void acquireShared(int arg)\npublic final boolean releaseShared(int arg)<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7528\u4e8e\u652f\u6301\u591a\u4e2a\u7ebf\u7a0b\u5171\u4eab\u8d44\u6e90\uff08\u5982\u4fe1\u53f7\u91cf\uff09<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e94\u3001\u5178\u578b\u5b9e\u73b0\u793a\u4f8b\uff08\u57fa\u4e8e AQS\uff09<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u540c\u6b65\u5de5\u5177<\/th><th>\u4f7f\u7528\u6a21\u5f0f<\/th><th>\u8bf4\u660e<\/th><\/tr><\/thead><tbody><tr><td><code>ReentrantLock<\/code><\/td><td>\u72ec\u5360<\/td><td>\u53ef\u91cd\u5165\u9501<\/td><\/tr><tr><td><code>Semaphore<\/code><\/td><td>\u5171\u4eab<\/td><td>\u63a7\u5236\u5e76\u53d1\u7ebf\u7a0b\u6570<\/td><\/tr><tr><td><code>CountDownLatch<\/code><\/td><td>\u5171\u4eab<\/td><td>\u7b49\u5f85\u5176\u4ed6\u7ebf\u7a0b\u5b8c\u6210<\/td><\/tr><tr><td><code>ReentrantReadWriteLock<\/code><\/td><td>\u5171\u4eab+\u72ec\u5360<\/td><td>\u8bfb\u5171\u4eab\uff0c\u5199\u72ec\u5360<\/td><\/tr><tr><td><code>FutureTask<\/code><\/td><td>\u72ec\u5360<\/td><td>\u63a7\u5236\u4efb\u52a1\u6267\u884c\u4e00\u6b21\u6027\u5b8c\u6210<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u516d\u3001\u6df1\u5165\u5173\u952e\u70b9<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1. CLH \u961f\u5217\uff08\u94fe\u8868\u961f\u5217\uff09<\/h3>\n\n\n\n<p>AQS \u4f7f\u7528\u4e86 CLH\uff08Craig, Landin, and Hagersten\uff09\u961f\u5217\u5b9e\u73b0\u7ebf\u7a0b\u7684\u6392\u961f\u7b49\u5f85\uff0c\u5177\u6709<strong>\u975e\u963b\u585e\u3001\u81ea\u65cb<\/strong>\u7684\u7279\u6027\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>head \u2192 Node1 \u2192 Node2 \u2192 Node3 \u2192 ...<\/code><\/pre>\n\n\n\n<p>\u6bcf\u4e2a <code>Node<\/code> \u5305\u542b\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>thread<\/code>\uff1a\u7ebf\u7a0b\u672c\u8eab<\/li>\n\n\n\n<li><code>waitStatus<\/code>\uff1a\u7b49\u5f85\u72b6\u6001\uff08\u5982 <code>SIGNAL<\/code>, <code>CANCELLED<\/code>, <code>CONDITION<\/code>\uff09<\/li>\n\n\n\n<li><code>prev\/next<\/code>\uff1a\u524d\u540e\u6307\u9488<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">2. \u72b6\u6001\u53d8\u91cf <code>state<\/code><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6240\u6709\u540c\u6b65\u5668\u7684\u6838\u5fc3\u72b6\u6001\u90fd\u4fdd\u5b58\u5728 <code>int state<\/code> \u4e2d\uff1b<\/li>\n\n\n\n<li>\u5b50\u7c7b\u901a\u8fc7 <code>getState()<\/code> \/ <code>setState()<\/code> \/ <code>compareAndSetState()<\/code> \u64cd\u4f5c\uff1b<\/li>\n\n\n\n<li>\u652f\u6301<strong>\u591a\u91cd\u52a0\u9501\uff08\u91cd\u5165\u9501\uff09<\/strong>\u6216<strong>\u8ba1\u6570<\/strong>\uff08\u5982\u4fe1\u53f7\u91cf permits\uff09\uff1b<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3. CAS \u4fdd\u8bc1\u7ebf\u7a0b\u5b89\u5168<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>protected final boolean compareAndSetState(int expect, int update)<\/code><\/pre>\n\n\n\n<p>AQS \u4f9d\u8d56\u5e95\u5c42 <code>Unsafe<\/code> \u7c7b\u7684 CAS \u5b9e\u73b0\uff08Compare And Swap\uff09\uff0c\u907f\u514d\u52a0\u9501\u5f00\u9500\uff0c\u5b9e\u73b0\u975e\u963b\u585e\u5e76\u53d1\u63a7\u5236\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e03\u3001\u5b9e\u6218\u6848\u4f8b\uff1a\u81ea\u5b9a\u4e49\u72ec\u5360\u9501<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>class MyLock extends AbstractQueuedSynchronizer {\n    public boolean tryAcquire(int acquires) {\n        if (compareAndSetState(0, acquires)) {\n            setExclusiveOwnerThread(Thread.currentThread());\n            return true;\n        }\n        return false;\n    }\n\n    protected boolean tryRelease(int releases) {\n        setExclusiveOwnerThread(null);\n        setState(0);\n        return true;\n    }\n\n    public void lock() {\n        acquire(1);\n    }\n\n    public void unlock() {\n        release(1);\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u516b\u3001\u76f8\u5173\u6e90\u7801\u5165\u53e3\uff08JDK\uff09<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>AbstractQueuedSynchronizer.java<\/code><br>GitHub \u94fe\u63a5\uff08OpenJDK\uff09:<br>\ud83d\udd17 <a href=\"https:\/\/github.com\/openjdk\/jdk\/blob\/master\/src\/java.base\/share\/classes\/java\/util\/concurrent\/locks\/AbstractQueuedSynchronizer.java\">https:\/\/github.com\/openjdk\/jdk\/blob\/master\/src\/java.base\/share\/classes\/java\/util\/concurrent\/locks\/AbstractQueuedSynchronizer.java<\/a><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e5d\u3001\u5b66\u4e60\u8d44\u6599\u63a8\u8350<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u300aJava \u5e76\u53d1\u7f16\u7a0b\u5b9e\u6218\u300b<\/strong> \u2013 Brian Goetz<\/li>\n\n\n\n<li><strong>\u300a\u6df1\u5165\u7406\u89e3 Java \u865a\u62df\u673a\u300b<\/strong> \u2013 \u5468\u5fd7\u660e<\/li>\n\n\n\n<li><strong>JDK \u5b98\u65b9\u6587\u6863<\/strong>:<br>\ud83d\udd17 <a href=\"https:\/\/docs.oracle.com\/javase\/8\/docs\/api\/java\/util\/concurrent\/locks\/AbstractQueuedSynchronizer.html\">https:\/\/docs.oracle.com\/javase\/8\/docs\/api\/java\/util\/concurrent\/locks\/AbstractQueuedSynchronizer.html<\/a><\/li>\n\n\n\n<li><strong>AQS \u53ef\u89c6\u5316\u56fe\u89e3<\/strong>:<br><a href=\"https:\/\/tech.meituan.com\/2019\/12\/05\/aqs-theory-and-apply.html\">https:\/\/tech.meituan.com\/2019\/12\/05\/aqs-theory-and-apply.html<\/a> \uff08\u63a8\u8350\u9605\u8bfb\uff09<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u5341\u3001\u603b\u7ed3\uff1aAQS \u7684\u4f18\u7f3a\u70b9<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u4f18\u70b9<\/th><th>\u7f3a\u70b9<\/th><\/tr><\/thead><tbody><tr><td>\u7edf\u4e00\u5e76\u53d1\u63a7\u5236\u6846\u67b6\uff0c\u7075\u6d3b\u6027\u9ad8<\/td><td>\u5b66\u4e60\u66f2\u7ebf\u9661\u5ced<\/td><\/tr><tr><td>\u652f\u6301\u72ec\u5360\u3001\u5171\u4eab\u6a21\u5f0f\u5207\u6362<\/td><td>\u4e0d\u6613\u8c03\u8bd5\uff08\u5e95\u5c42\u4f9d\u8d56 CAS\u3001\u81ea\u65cb\uff09<\/td><\/tr><tr><td>\u9ad8\u6027\u80fd\u3001\u975e\u963b\u585e<\/td><td>\u4f7f\u7528\u4e0d\u5f53\u5bb9\u6613\u6b7b\u9501<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>AbstractQueuedSynchronizer\uff08\u7b80\u79f0 AQS\uff09\u662f Java \u5e76\u53d1\u5305 java.util. [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3840,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68],"tags":[],"class_list":["post-3839","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3839","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=3839"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3839\/revisions"}],"predecessor-version":[{"id":3841,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3839\/revisions\/3841"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media\/3840"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=3839"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=3839"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=3839"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}