{"id":3937,"date":"2025-07-20T11:00:20","date_gmt":"2025-07-20T03:00:20","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3937"},"modified":"2025-07-20T11:00:20","modified_gmt":"2025-07-20T03:00:20","slug":"clh-%e9%98%9f%e5%88%97%e5%a6%82%e4%bd%95%e5%9c%a8-reentrantreadwritelock-%e4%b8%ad%e8%a2%ab%e6%89%a9%e5%b1%95%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/07\/20\/clh-%e9%98%9f%e5%88%97%e5%a6%82%e4%bd%95%e5%9c%a8-reentrantreadwritelock-%e4%b8%ad%e8%a2%ab%e6%89%a9%e5%b1%95%ef%bc%9f\/","title":{"rendered":"CLH \u961f\u5217\u5982\u4f55\u5728 ReentrantReadWriteLock \u4e2d\u88ab\u6269\u5c55\uff1f"},"content":{"rendered":"\n<p>\u8fd9\u662f\u4e00\u4e2a\u975e\u5e38\u6df1\u5165\u3001\u5e95\u5c42\u7684\u95ee\u9898\uff0c\u4e0b\u9762\u6211\u4eec\u5c06<strong>\u7cfb\u7edf\u6027\u5256\u6790<\/strong>\uff1a<code>CLH \u961f\u5217<\/code> \u662f\u5982\u4f55\u88ab\u6269\u5c55\u548c\u590d\u7528\uff0c\u5728 Java \u5e76\u53d1\u5305\u4e2d\u7684 <code>ReentrantReadWriteLock<\/code>\uff08\u8bfb\u5199\u9501\uff09\u4e2d\u5b9e\u73b0\u591a\u7ebf\u7a0b\u7684\u5b89\u5168\u8c03\u5ea6\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e00\u3001\u524d\u63d0\u80cc\u666f\uff1aCLH \u662f AQS \u7684\u57fa\u7840\u961f\u5217\u6a21\u578b<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>ReentrantReadWriteLock<\/code> \u662f\u901a\u8fc7 <code>AQS<\/code> \u5b9e\u73b0\u7684\u3002<\/li>\n\n\n\n<li><code>AQS<\/code> \u672c\u8eab\u4f7f\u7528**\u53d8\u79cd\u7684 CLH \u961f\u5217\uff08\u53cc\u5411 FIFO \u961f\u5217\uff09**\u6765\u5b9e\u73b0\u7ebf\u7a0b\u963b\u585e\u4e0e\u5524\u9192\u3002<\/li>\n\n\n\n<li><code>ReadWriteLock<\/code> \u7684\u6311\u6218\u5728\u4e8e\u5b83\u8981\u5904\u7406\u4e24\u79cd\u8d44\u6e90\u8bbf\u95ee\u65b9\u5f0f\uff1a<\/li>\n\n\n\n<li>\u591a\u7ebf\u7a0b <strong>\u5171\u4eab\u8bfb\uff08Shared\uff09<\/strong><\/li>\n\n\n\n<li>\u5355\u7ebf\u7a0b <strong>\u72ec\u5360\u5199\uff08Exclusive\uff09<\/strong><\/li>\n<\/ul>\n\n\n\n<p>\u8fd9\u5c31\u610f\u5473\u7740\uff1a<strong>\u4e00\u5957\u961f\u5217\u8981\u652f\u6301\u4e24\u79cd\u6a21\u5f0f\u7684\u7ebf\u7a0b\u8c03\u5ea6\u884c\u4e3a<\/strong>\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\u7c7b\u5173\u7cfb\u7ed3\u6784<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>ReentrantReadWriteLock\n \u251c\u2500\u2500 Sync\uff08\u7ee7\u627f AQS\uff09\n       \u251c\u2500\u2500 FairSync\n       \u2514\u2500\u2500 NonfairSync<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>ReentrantReadWriteLock.Sync<\/code> \u662f\u7ee7\u627f\u81ea <code>AbstractQueuedSynchronizer<\/code> \u7684\u3002<\/li>\n\n\n\n<li>\u5b83\u5b9a\u4e49\u4e86 <code>tryAcquire<\/code>, <code>tryRelease<\/code>, <code>tryAcquireShared<\/code>, <code>tryReleaseShared<\/code> \u7b49\u65b9\u6cd5\uff0c\u652f\u6301\u72ec\u5360\u4e0e\u5171\u4eab\u4e24\u79cd\u6a21\u5f0f\u3002<\/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\">\u4e09\u3001CLH \u961f\u5217\u5982\u4f55\u6269\u5c55\u652f\u6301\u8bfb\u5199\u9501<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1. <code>Node<\/code> \u8282\u70b9\u4e2d\u7684\u5171\u4eab\/\u72ec\u5360\u6807\u8bc6<\/h3>\n\n\n\n<p>AQS \u7684 <code>Node<\/code> \u7c7b\u4e2d\u6709\u4e24\u4e2a\u6807\u8bc6\u6a21\u5f0f\u7684\u5e38\u91cf\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>static final Node SHARED = new Node();\nstatic final Node EXCLUSIVE = null;<\/code><\/pre>\n\n\n\n<p>\u5728\u6784\u5efa CLH \u961f\u5217\u65f6\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8bfb\u7ebf\u7a0b\uff08\u5171\u4eab\uff09\u2192 <code>node.shared = SHARED<\/code><\/li>\n\n\n\n<li>\u5199\u7ebf\u7a0b\uff08\u72ec\u5360\uff09\u2192 <code>node.shared = EXCLUSIVE<\/code><\/li>\n<\/ul>\n\n\n\n<p>CLH \u961f\u5217\u7ed3\u6784\u53d8\u6210\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>head \u2192 &#91;W] \u2192 &#91;R] \u2192 &#91;R] \u2192 &#91;W] \u2192 ...<\/code><\/pre>\n\n\n\n<p>\u5176\u4e2d <code>[W]<\/code> \u8868\u793a\u5199\u8282\u70b9\uff08Exclusive\uff09\uff0c<code>[R]<\/code> \u8868\u793a\u8bfb\u8282\u70b9\uff08Shared\uff09<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">2. <code>tryAcquireShared()<\/code> \u4e0e <code>tryAcquire()<\/code> \u533a\u522b<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5199\u9501\u4f7f\u7528 <code>AQS.tryAcquire()<\/code>\uff08\u72ec\u5360\u6a21\u5f0f\uff09<\/li>\n\n\n\n<li>\u8bfb\u9501\u4f7f\u7528 <code>AQS.tryAcquireShared()<\/code>\uff08\u5171\u4eab\u6a21\u5f0f\uff09<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">\u793a\u4f8b\uff1a\u8bfb\u7ebf\u7a0b\u8c03\u7528 lock() \u2192 \u5c1d\u8bd5\u5171\u4eab\u83b7\u53d6<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>protected final int tryAcquireShared(int unused) {\n    Thread current = Thread.currentThread();\n    int c = getState();\n\n    \/\/ \u5224\u65ad\u662f\u5426\u5df2\u6709\u5199\u9501\n    if (exclusiveCount(c) != 0 &amp;&amp;\n        getExclusiveOwnerThread() != current) {\n        return -1;\n    }\n\n    \/\/ \u5c1d\u8bd5\u589e\u52a0\u8bfb\u9501\u6570\u91cf\uff08state \u4f4e 16 \u4f4d\uff09\n    if (sharedCount(c) == MAX_COUNT)\n        throw new Error(\"Maximum lock count exceeded\");\n\n    if (compareAndSetState(c, c + SHARED_UNIT)) {\n        ...\n        return 1; \/\/ \u6210\u529f\n    }\n\n    return -1; \/\/ \u5931\u8d25\u8fdb\u5165 CLH \u961f\u5217\n}<\/code><\/pre>\n\n\n\n<p>\u8bf4\u660e\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8bfb\u7ebf\u7a0b\u5931\u8d25\u540e\uff0c\u4f1a\u4ee5\u5171\u4eab\u6a21\u5f0f\u52a0\u5165 CLH \u961f\u5217\u3002<\/li>\n\n\n\n<li>\u5524\u9192\u65f6\uff0c\u53ea\u8981\u524d\u9762\u6ca1\u6709\u5199\u7ebf\u7a0b\uff0c\u5c31\u53ef\u4ee5<strong>\u540c\u65f6\u5524\u9192\u591a\u4e2a\u8bfb\u7ebf\u7a0b<\/strong>\u3002<\/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\">\u56db\u3001\u6269\u5c55\u5173\u952e\u70b9\uff1a\u8bfb\u5199\u961f\u5217\u6df7\u5408\u8c03\u5ea6\u7b56\u7565<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1. \u8bfb\u5171\u4eab\uff08Read-Shared\uff09\u7b56\u7565<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u591a\u4e2a\u8bfb\u7ebf\u7a0b\u53ef\u540c\u65f6\u6301\u6709\u9501\uff0c\u524d\u63d0\u662f\u6ca1\u6709\u5199\u7ebf\u7a0b\u6301\u6709\u6216\u5728\u524d\u9762\u6392\u961f\u3002<\/li>\n\n\n\n<li>\u6761\u4ef6\u5224\u65ad\uff1a\u5f53\u524d\u961f\u5217\u4e2d\u524d\u9762\u662f\u5426\u6709\u5199\u7ebf\u7a0b\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5982\u679c\u961f\u9996\u662f\u5199\u7ebf\u7a0b\uff0c\u8bfb\u7ebf\u7a0b\u5c06\u88ab\u963b\u585e\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. \u5199\u72ec\u5360\uff08Write-Exclusive\uff09\u7b56\u7565<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5199\u7ebf\u7a0b\u5fc5\u987b\u7b49\u6240\u6709\u8bfb\u7ebf\u7a0b\u548c\u5176\u4ed6\u5199\u7ebf\u7a0b\u91ca\u653e\u540e\uff0c\u624d\u53ef\u83b7\u53d6\u9501\u3002<\/li>\n\n\n\n<li>\u5199\u7ebf\u7a0b\u83b7\u53d6\u6210\u529f\u540e\uff0c\u5176\u4ed6\u7ebf\u7a0b\u90fd\u5fc5\u987b\u6392\u961f\u3002<\/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\u3001CLH \u5728\u8bfb\u5199\u9501\u4e2d\u7684\u5b9e\u9645\u8868\u73b0\u5f62\u5f0f<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">CLH \u961f\u5217\u6df7\u5408\u72b6\u6001\uff1a<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>head \u2192 &#91;W] \u2192 &#91;R] \u2192 &#91;R] \u2192 &#91;W] \u2192 &#91;R] \u2192 ...\n         \u2191     \u2191     \u2191\n      \u8fd9\u4e9b\u8bfb\u7ebf\u7a0b\u4e0d\u80fd\u6267\u884c\uff08\u88ab\u524d\u9762\u7684\u5199\u9501\u963b\u585e\uff09<\/code><\/pre>\n\n\n\n<p>\u5f53\u5199\u9501\u91ca\u653e\u540e\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u961f\u5217\u4ece\u524d\u5411\u540e\u68c0\u67e5\u662f\u5426\u53ef\u4ee5<strong>\u6279\u91cf\u5524\u9192\u591a\u4e2a\u5171\u4eab\u8282\u70b9\uff08\u8bfb\u7ebf\u7a0b\uff09<\/strong>\u3002<\/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\">\u516d\u3001\u4e3a\u4ec0\u4e48\u7528 CLH \u6269\u5c55\u800c\u4e0d\u662f\u53e6\u5efa\u961f\u5217\uff1f<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u4f18\u70b9\uff1a<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u4f18\u70b9<\/th><th>\u8bf4\u660e<\/th><\/tr><\/thead><tbody><tr><td>\u590d\u7528\u7edf\u4e00\u961f\u5217<\/td><td>\u4e0d\u9700\u8981\u7ef4\u62a4\u4e24\u4e2a\u72ec\u7acb\u7684\u8bfb\/\u5199\u7b49\u5f85\u961f\u5217\uff0c\u964d\u4f4e\u590d\u6742\u5ea6<\/td><\/tr><tr><td>\u540c\u6b65\/\u5171\u4eab\u901a\u7528\u8c03\u5ea6\u673a\u5236<\/td><td>AQS \u652f\u6301\u5171\u4eab &amp; \u72ec\u5360\uff0c\u961f\u5217\u8282\u70b9\u8bbe\u8ba1\u5df2\u80fd\u533a\u5206<\/td><\/tr><tr><td>\u4fdd\u6301 FIFO \u516c\u5e73\u7b56\u7565<\/td><td>\u5199\u7ebf\u7a0b\u4e5f\u80fd\u57fa\u4e8e FIFO \u6392\u961f\uff0c\u907f\u514d\u5199\u9965\u997f<\/td><\/tr><tr><td>\u652f\u6301\u6761\u4ef6\u961f\u5217\uff08Condition\uff09<\/td><td>\u4fdd\u7559 <code>ConditionObject<\/code> \u5b9e\u73b0\u673a\u5236\uff0c\u65e0\u9700\u91cd\u5199 Condition \u7ba1\u7406\u903b\u8f91<\/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\">\u4e03\u3001\u6e90\u7801\u5165\u53e3\u5efa\u8bae\u9605\u8bfb\u8def\u5f84<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u529f\u80fd<\/th><th>\u6e90\u7801\u65b9\u6cd5<\/th><\/tr><\/thead><tbody><tr><td>\u5199\u9501\u52a0\u9501<\/td><td><code>ReentrantReadWriteLock.WriteLock.lock()<\/code><\/td><\/tr><tr><td>\u5199\u9501\u6838\u5fc3\u903b\u8f91<\/td><td><code>Sync.tryAcquire()<\/code><\/td><\/tr><tr><td>\u8bfb\u9501\u52a0\u9501<\/td><td><code>ReentrantReadWriteLock.ReadLock.lock()<\/code><\/td><\/tr><tr><td>\u8bfb\u9501\u6838\u5fc3\u903b\u8f91<\/td><td><code>Sync.tryAcquireShared()<\/code><\/td><\/tr><tr><td>CLH \u5165\u961f\u903b\u8f91<\/td><td><code>AQS.enqueue(Node)<\/code><\/td><\/tr><tr><td>\u8282\u70b9\u6a21\u5f0f\u5224\u65ad<\/td><td><code>Node.shared<\/code>, <code>Node.exclusive<\/code><\/td><\/tr><tr><td>\u5524\u9192\u8bfb\u7ebf\u7a0b\u903b\u8f91<\/td><td><code>doReleaseShared()<\/code><\/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\">\u516b\u3001\u53c2\u8003\u8d44\u6599<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/github.com\/openjdk\/jdk\/blob\/master\/src\/java.base\/share\/classes\/java\/util\/concurrent\/locks\/ReentrantReadWriteLock.java\">OpenJDK ReentrantReadWriteLock \u6e90\u7801<\/a><\/li>\n\n\n\n<li> <a href=\"https:\/\/github.com\/openjdk\/jdk\/blob\/master\/src\/java.base\/share\/classes\/java\/util\/concurrent\/locks\/AbstractQueuedSynchronizer.java\">OpenJDK AbstractQueuedSynchronizer \u6e90\u7801<\/a><\/li>\n\n\n\n<li> <em>Java \u5e76\u53d1\u7f16\u7a0b\u5b9e\u6218<\/em> \u7b2c 13 \u7ae0\u300114 \u7ae0<\/li>\n\n\n\n<li> <em>\u6df1\u5165\u7406\u89e3 Java \u865a\u62df\u673a<\/em> \u2014 \u9501\u673a\u5236\u5b9e\u73b0<\/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\">\u603b\u7ed3\u53e3\u8bc0<\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>CLH \u961f\u5217\u914d AQS\uff0c\u8bfb\u5199\u6a21\u5f0f\u80fd\u5171\u821e\uff1b<br>\u72ec\u5360\u62a2\u9501\u662f\u5199\u7ebf\u7a0b\uff0c\u5171\u4eab\u6392\u961f\u662f\u8bfb\u7ebf\u7a0b\uff1b<br>\u4e00\u4e2a\u961f\u5217\u641e\u5b9a\u5b83\uff0c\u516c\u5e73\u9ad8\u6548\u6ca1\u8bdd\u8bf4\uff01<\/p>\n<\/blockquote>\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>\u8fd9\u662f\u4e00\u4e2a\u975e\u5e38\u6df1\u5165\u3001\u5e95\u5c42\u7684\u95ee\u9898\uff0c\u4e0b\u9762\u6211\u4eec\u5c06\u7cfb\u7edf\u6027\u5256\u6790\uff1aCLH \u961f\u5217 \u662f\u5982\u4f55\u88ab\u6269\u5c55\u548c\u590d\u7528\uff0c\u5728 Java \u5e76\u53d1\u5305\u4e2d\u7684 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3938,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68,86],"tags":[],"class_list":["post-3937","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java","category-java-"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3937","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=3937"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3937\/revisions"}],"predecessor-version":[{"id":3939,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3937\/revisions\/3939"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media\/3938"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=3937"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=3937"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=3937"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}