{"id":3404,"date":"2018-11-22T16:37:50","date_gmt":"2018-11-22T08:37:50","guid":{"rendered":"http:\/\/www.xttblog.com\/?p=3404"},"modified":"2018-11-22T16:37:50","modified_gmt":"2018-11-22T08:37:50","slug":"%e4%bb%8e-reentrantreadwritelock-%e8%af%b4%e7%8b%ac%e4%ba%ab%e9%94%81%e6%8e%92%e4%bb%96%e9%94%81%e4%b8%8e%e5%85%b1%e4%ba%ab%e9%94%81","status":"publish","type":"post","link":"https:\/\/www.xttblog.com\/?p=3404","title":{"rendered":"\u4ece ReentrantReadWriteLock \u8bf4\u72ec\u4eab\u9501(\u6392\u4ed6\u9501)\u4e0e\u5171\u4eab\u9501"},"content":{"rendered":"<p>\n\t\u9605\u8bfb\u524d\u9762\u7684\u6587\u7ae0\uff0c\u6211\u4eec\u77e5\u9053 ReentrantLock \u662f\u4e00\u4e2a\u9ad8\u6548\u7684\u9501\uff0c\u5b83\u65e2\u80fd\u7528\u4f5c\u516c\u5e73\u9501\uff0c\u53c8\u80fd\u7528\u4f5c\u975e\u516c\u5e73\u9501\uff01\u4f46\u662f\u6709\u4e86 ReentrantLock \u540e\uff0c\u4e3a\u4ec0\u4e48\u8fd8\u9700\u8981 ReentrantReadWriteLock \u5462\uff1f\n<\/p>\n<p>\n\t\u90a3\u5c31\u9700\u8981\u4ece\u6392\u4ed6\u9501\u548c\u5171\u4eab\u9501\u8bf4\u8d77\uff01\n<\/p>\n<h2>\n\t\u72ec\u4eab\u9501<br \/>\n<\/h2>\n<p>\n\t\u6392\u4ed6\u9501\uff0c\u53c8\u53eb\u505a\u72ec\u4eab\u9501\u3002\u987e\u540d\u601d\u4e49\u5c31\u662f\u6307\u8be5\u9501\u4e00\u6b21\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6240\u6301\u6709\u3002\u5982\u679c\u7ebf\u7a0b T \u5bf9\u6570\u636e A \u52a0\u4e0a\u6392\u5b83\u9501\u540e\uff0c\u5219\u5176\u4ed6\u7ebf\u7a0b\u4e0d\u80fd\u518d\u5bf9 A \u52a0\u4efb\u4f55\u7c7b\u578b\u7684\u9501\u3002\u83b7\u5f97\u6392\u5b83\u9501\u7684\u7ebf\u7a0b\u5373\u80fd\u8bfb\u6570\u636e\u53c8\u80fd\u4fee\u6539\u6570\u636e\u3002JDK \u4e2d\u7684 synchronized \u548c JUC \u4e2d Lock \u7684\u5b9e\u73b0\u7c7b\u5c31\u662f\u4e92\u65a5\u9501\u3002\n<\/p>\n<h2>\n\t\u5171\u4eab\u9501<br \/>\n<\/h2>\n<p>\n\t\u5171\u4eab\u9501\u662f\u6307\u8be5\u9501\u53ef\u88ab\u591a\u4e2a\u7ebf\u7a0b\u6240\u6301\u6709\u3002\u5982\u679c\u7ebf\u7a0b T \u5bf9\u6570\u636e A \u52a0\u4e0a\u5171\u4eab\u9501\u540e\uff0c\u5219\u5176\u4ed6\u7ebf\u7a0b\u53ea\u80fd\u5bf9 A \u518d\u52a0\u5171\u4eab\u9501\uff0c\u4e0d\u80fd\u52a0\u6392\u5b83\u9501\u3002\u83b7\u5f97\u5171\u4eab\u9501\u7684\u7ebf\u7a0b\u53ea\u80fd\u8bfb\u6570\u636e\uff0c\u4e0d\u80fd\u4fee\u6539\u6570\u636e\u3002\n<\/p>\n<p>\n\t\u72ec\u4eab\u9501\u4e0e\u5171\u4eab\u9501\u4e5f\u662f\u901a\u8fc7 AQS \u6765\u5b9e\u73b0\u7684\uff0c\u901a\u8fc7\u5b9e\u73b0\u4e0d\u540c\u7684\u65b9\u6cd5\uff0c\u6765\u5b9e\u73b0\u72ec\u4eab\u6216\u8005\u5171\u4eab\u3002\n<\/p>\n<p>\n\t\u4e0b\u9762\u6211\u4eec\u4e00\u8d77\u6765\u770b\u770b ReentrantReadWriteLock \u7684\u6e90\u7801\uff1a\n<\/p>\n<p>\n\t<img decoding=\"async\" alt=\"ReentrantReadWriteLock \u6e90\u7801\u5206\u6790\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/Java_Lock_%20ReentrantReadWriteLock.png\" style=\"width: 1850px;height: 1076px\" \/>ReentrantReadWriteLock \u6709\u4e24\u628a\u9501\uff1aReadLock \u548c WriteLock\uff0c\u7531\u8bcd\u77e5\u610f\uff0c\u4e00\u4e2a\u8bfb\u9501\u4e00\u4e2a\u5199\u9501\uff0c\u5408\u79f0&ldquo;\u8bfb\u5199\u9501&rdquo;\u3002\u518d\u8fdb\u4e00\u6b65\u89c2\u5bdf\u53ef\u4ee5\u53d1\u73b0 ReadLock \u548c WriteLock \u662f\u9760\u5185\u90e8\u7c7b Sync \u5b9e\u73b0\u7684\u9501\u3002Sync \u662f AQS \u7684\u4e00\u4e2a\u5b50\u7c7b\uff0c\u8fd9\u79cd\u7ed3\u6784\u5728 CountDownLatch\u3001ReentrantLock\u3001Semaphore \u91cc\u9762\u4e5f\u90fd\u5b58\u5728\u3002\n<\/p>\n<p>\n\t\u5728 ReentrantReadWriteLock \u91cc\u9762\uff0c\u8bfb\u9501\u548c\u5199\u9501\u7684\u9501\u4e3b\u4f53\u90fd\u662f Sync\uff0c\u4f46\u8bfb\u9501\u548c\u5199\u9501\u7684\u52a0\u9501\u65b9\u5f0f\u4e0d\u4e00\u6837\u3002\u8bfb\u9501\u662f\u5171\u4eab\u9501\uff0c\u5199\u9501\u662f\u72ec\u4eab\u9501\u3002\u8bfb\u9501\u7684\u5171\u4eab\u9501\u53ef\u4fdd\u8bc1\u5e76\u53d1\u8bfb\u975e\u5e38\u9ad8\u6548\uff0c\u800c\u8bfb\u5199\u3001\u5199\u8bfb\u3001\u5199\u5199\u7684\u8fc7\u7a0b\u4e92\u65a5\uff0c\u56e0\u4e3a\u8bfb\u9501\u548c\u5199\u9501\u662f\u5206\u79bb\u7684\u3002\u6240\u4ee5 ReentrantReadWriteLock \u7684\u5e76\u53d1\u6027\u76f8\u6bd4\u4e00\u822c\u7684\u4e92\u65a5\u9501\u6709\u4e86\u5f88\u5927\u63d0\u5347\u3002\n<\/p>\n<p>\n\t\u90a3\u8bfb\u9501\u548c\u5199\u9501\u7684\u5177\u4f53\u52a0\u9501\u65b9\u5f0f\u6709\u4ec0\u4e48\u533a\u522b\u5462\uff1f\u5728\u4e86\u89e3\u6e90\u7801\u4e4b\u524d\u6211\u4eec\u9700\u8981\u56de\u987e\u4e00\u4e0b\u5176\u4ed6\u77e5\u8bc6\u3002<br \/>\n\t\u5728\u6700\u5f00\u59cb\u63d0\u53caAQS\u7684\u65f6\u5019\u6211\u4eec\u4e5f\u63d0\u5230\u4e86 state \u5b57\u6bb5\uff08int\u7c7b\u578b\uff0c32\u4f4d\uff09\uff0c\u8be5\u5b57\u6bb5\u7528\u6765\u63cf\u8ff0\u6709\u591a\u5c11\u7ebf\u7a0b\u83b7\u6301\u6709\u9501\u3002\n<\/p>\n<p>\n\t\u5728\u72ec\u4eab\u9501\u4e2d\u8fd9\u4e2a\u503c\u901a\u5e38\u662f 0 \u6216\u8005 1\uff08\u5982\u679c\u662f\u91cd\u5165\u9501\u7684\u8bddstate\u503c\u5c31\u662f\u91cd\u5165\u7684\u6b21\u6570\uff09\uff0c\u5728\u5171\u4eab\u9501\u4e2d state \u5c31\u662f\u6301\u6709\u9501\u7684\u6570\u91cf\u3002\u4f46\u662f\u5728 ReentrantReadWriteLock \u4e2d\u6709\u8bfb\u3001\u5199\u4e24\u628a\u9501\uff0c\u6240\u4ee5\u9700\u8981\u5728\u4e00\u4e2a\u6574\u578b\u53d8\u91cf state \u4e0a\u5206\u522b\u63cf\u8ff0\u8bfb\u9501\u548c\u5199\u9501\u7684\u6570\u91cf\uff08\u6216\u8005\u4e5f\u53ef\u4ee5\u53eb\u72b6\u6001\uff09\u3002\u4e8e\u662f\u5c06 state \u53d8\u91cf&ldquo;\u6309\u4f4d\u5207\u5272&rdquo;\u5207\u5206\u6210\u4e86\u4e24\u4e2a\u90e8\u5206\uff0c\u9ad8 16 \u4f4d\u8868\u793a\u8bfb\u9501\u72b6\u6001\uff08\u8bfb\u9501\u4e2a\u6570\uff09\uff0c\u4f4e 16 \u4f4d\u8868\u793a\u5199\u9501\u72b6\u6001\uff08\u5199\u9501\u4e2a\u6570\uff09\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a\n<\/p>\n<p>\n\t<img decoding=\"async\" alt=\"ReentrantReadWriteLock \u8bfb\u5199\u9501\u7684\u9ad8\u4f4e16\u4f4d\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/java-lock-32-bit.png\" style=\"width: 726px;height: 81px\" \/>\n<\/p>\n<p>\n\t\u660e\u767d\u4e86\u8fd9\u4e2a\u4e4b\u540e\uff0c\u6211\u4eec\u518d\u6765\u770b\u5199\u9501\u7684\u52a0\u9501\u6e90\u7801\uff1a\n<\/p>\n<pre class=\"brush:java;\">\r\nprotected final boolean tryAcquire(int acquires) {\r\n    Thread current = Thread.currentThread();\r\n    int c = getState(); \/\/ \u53d6\u5230\u5f53\u524d\u9501\u7684\u4e2a\u6570\r\n    int w = exclusiveCount(c); \/\/ \u53d6\u5199\u9501\u7684\u4e2a\u6570w\r\n    if (c != 0) { \/\/ \u5982\u679c\u5df2\u7ecf\u6709\u7ebf\u7a0b\u6301\u6709\u4e86\u9501(c!=0)\r\n        \/\/ (Note: if c != 0 and w == 0 then shared count != 0)\r\n        \/\/ \u5982\u679c\u5199\u7ebf\u7a0b\u6570\uff08w\uff09\u4e3a0\uff08\u6362\u8a00\u4e4b\u5b58\u5728\u8bfb\u9501\uff09 \u6216\u8005\u6301\u6709\u9501\u7684\u7ebf\u7a0b\u4e0d\u662f\u5f53\u524d\u7ebf\u7a0b\u5c31\u8fd4\u56de\u5931\u8d25\r\n        if (w == 0 || current != getExclusiveOwnerThread()) \r\n            return false;\r\n        \/\/ \u5982\u679c\u5199\u5165\u9501\u7684\u6570\u91cf\u5927\u4e8e\u6700\u5927\u6570\uff0865535\uff0c2\u768416\u6b21\u65b9-1\uff09\u5c31\u629b\u51fa\u4e00\u4e2aError\u3002\r\n        if (w + exclusiveCount(acquires) &gt; MAX_COUNT)    \r\n            throw new Error(&quot;Maximum lock count exceeded&quot;);\r\n        \/\/ Reentrant acquire\r\n    setState(c + acquires);\r\n    return true;\r\n  }\r\n  if (writerShouldBlock() || !compareAndSetState(c, c + acquires)) \r\n    \/\/ \u5982\u679c\u5f53\u4e14\u5199\u7ebf\u7a0b\u6570\u4e3a0\uff0c\u5e76\u4e14\u5f53\u524d\u7ebf\u7a0b\u9700\u8981\u963b\u585e\u90a3\u4e48\u5c31\u8fd4\u56de\u5931\u8d25\uff1b\u6216\u8005\u5982\u679c\u901a\u8fc7CAS\u589e\u52a0\u5199\u7ebf\u7a0b\u6570\u5931\u8d25\u4e5f\u8fd4\u56de\u5931\u8d25\u3002\r\n        return false;\r\n    \/\/ \u5982\u679cc=0\uff0cw=0\u6216\u8005c&gt;0\uff0cw&gt;0\uff08\u91cd\u5165\uff09\uff0c\u5219\u8bbe\u7f6e\u5f53\u524d\u7ebf\u7a0b\u6216\u9501\u7684\u62e5\u6709\u8005\r\n    setExclusiveOwnerThread(current); \r\n    return true;\r\n}<\/pre>\n<ul>\n<li>\n\t\t\u8fd9\u6bb5\u4ee3\u7801\u9996\u5148\u53d6\u5230\u5f53\u524d\u9501\u7684\u4e2a\u6570 c\uff0c\u7136\u540e\u518d\u901a\u8fc7c\u6765\u83b7\u53d6\u5199\u9501\u7684\u4e2a\u6570 w\u3002\u56e0\u4e3a\u5199\u9501\u662f\u4f4e 16 \u4f4d\uff0c\u6240\u4ee5\u53d6\u4f4e16\u4f4d\u7684\u6700\u5927\u503c\u4e0e\u5f53\u524d\u7684 c \u505a\u4e0e\u8fd0\u7b97\uff08 int w = exclusiveCount(c); \uff09\uff0c\u9ad8 16 \u4f4d\u548c 0 \u4e0e\u8fd0\u7b97\u540e\u662f 0\uff0c\u5269\u4e0b\u7684\u5c31\u662f\u4f4e\u4f4d\u8fd0\u7b97\u7684\u503c\uff0c\u540c\u65f6\u4e5f\u662f\u6301\u6709\u5199\u9501\u7684\u7ebf\u7a0b\u6570\u76ee\u3002\n\t<\/li>\n<li>\n\t\t\u5728\u53d6\u5230\u5199\u9501\u7ebf\u7a0b\u7684\u6570\u76ee\u540e\uff0c\u9996\u5148\u5224\u65ad\u662f\u5426\u5df2\u7ecf\u6709\u7ebf\u7a0b\u6301\u6709\u4e86\u9501\u3002\u5982\u679c\u5df2\u7ecf\u6709\u7ebf\u7a0b\u6301\u6709\u4e86\u9501(c!=0)\uff0c\u5219\u67e5\u770b\u5f53\u524d\u5199\u9501\u7ebf\u7a0b\u7684\u6570\u76ee\uff0c\u5982\u679c\u5199\u7ebf\u7a0b\u6570\u4e3a0\uff08\u5373\u6b64\u65f6\u5b58\u5728\u8bfb\u9501\uff09\u6216\u8005\u6301\u6709\u9501\u7684\u7ebf\u7a0b\u4e0d\u662f\u5f53\u524d\u7ebf\u7a0b\u5c31\u8fd4\u56de\u5931\u8d25\uff08\u6d89\u53ca\u5230\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u7684\u5b9e\u73b0\uff09\u3002\n\t<\/li>\n<li>\n\t\t\u5982\u679c\u5199\u5165\u9501\u7684\u6570\u91cf\u5927\u4e8e\u6700\u5927\u6570\uff0865535\uff0c2\u768416\u6b21\u65b9-1\uff09\u5c31\u629b\u51fa\u4e00\u4e2a Error\u3002\n\t<\/li>\n<li>\n\t\t\u5982\u679c\u5f53\u4e14\u5199\u7ebf\u7a0b\u6570\u4e3a0\uff08\u90a3\u4e48\u8bfb\u7ebf\u7a0b\u4e5f\u5e94\u8be5\u4e3a0\uff0c\u56e0\u4e3a\u4e0a\u9762\u5df2\u7ecf\u5904\u7406 c!=0 \u7684\u60c5\u51b5\uff09\uff0c\u5e76\u4e14\u5f53\u524d\u7ebf\u7a0b\u9700\u8981\u963b\u585e\u90a3\u4e48\u5c31\u8fd4\u56de\u5931\u8d25\uff1b\u5982\u679c\u901a\u8fc7 CAS \u589e\u52a0\u5199\u7ebf\u7a0b\u6570\u5931\u8d25\u4e5f\u8fd4\u56de\u5931\u8d25\u3002\n\t<\/li>\n<li>\n\t\t\u5982\u679c c=0,w=0 \u6216\u8005 c&gt;0,w&gt;0\uff08\u91cd\u5165\uff09\uff0c\u5219\u8bbe\u7f6e\u5f53\u524d\u7ebf\u7a0b\u6216\u9501\u7684\u62e5\u6709\u8005\uff0c\u8fd4\u56de\u6210\u529f\uff01\n\t<\/li>\n<\/ul>\n<p>\n\ttryAcquire() \u9664\u4e86\u91cd\u5165\u6761\u4ef6\uff08\u5f53\u524d\u7ebf\u7a0b\u4e3a\u83b7\u53d6\u4e86\u5199\u9501\u7684\u7ebf\u7a0b\uff09\u4e4b\u5916\uff0c\u589e\u52a0\u4e86\u4e00\u4e2a\u8bfb\u9501\u662f\u5426\u5b58\u5728\u7684\u5224\u65ad\u3002\u5982\u679c\u5b58\u5728\u8bfb\u9501\uff0c\u5219\u5199\u9501\u4e0d\u80fd\u88ab\u83b7\u53d6\uff0c\u539f\u56e0\u5728\u4e8e\uff1a\u5fc5\u987b\u786e\u4fdd\u5199\u9501\u7684\u64cd\u4f5c\u5bf9\u8bfb\u9501\u53ef\u89c1\uff0c\u5982\u679c\u5141\u8bb8\u8bfb\u9501\u5728\u5df2\u88ab\u83b7\u53d6\u7684\u60c5\u51b5\u4e0b\u5bf9\u5199\u9501\u7684\u83b7\u53d6\uff0c\u90a3\u4e48\u6b63\u5728\u8fd0\u884c\u7684\u5176\u4ed6\u8bfb\u7ebf\u7a0b\u5c31\u65e0\u6cd5\u611f\u77e5\u5230\u5f53\u524d\u5199\u7ebf\u7a0b\u7684\u64cd\u4f5c\u3002\n<\/p>\n<p>\n\t\u56e0\u6b64\uff0c\u53ea\u6709\u7b49\u5f85\u5176\u4ed6\u8bfb\u7ebf\u7a0b\u90fd\u91ca\u653e\u4e86\u8bfb\u9501\uff0c\u5199\u9501\u624d\u80fd\u88ab\u5f53\u524d\u7ebf\u7a0b\u83b7\u53d6\uff0c\u800c\u5199\u9501\u4e00\u65e6\u88ab\u83b7\u53d6\uff0c\u5219\u5176\u4ed6\u8bfb\u5199\u7ebf\u7a0b\u7684\u540e\u7eed\u8bbf\u95ee\u5747\u88ab\u963b\u585e\u3002\u5199\u9501\u7684\u91ca\u653e\u4e0e ReentrantLock \u7684\u91ca\u653e\u8fc7\u7a0b\u57fa\u672c\u7c7b\u4f3c\uff0c\u6bcf\u6b21\u91ca\u653e\u5747\u51cf\u5c11\u5199\u72b6\u6001\uff0c\u5f53\u5199\u72b6\u6001\u4e3a 0 \u65f6\u8868\u793a\u5199\u9501\u5df2\u88ab\u91ca\u653e\uff0c\u7136\u540e\u7b49\u5f85\u7684\u8bfb\u5199\u7ebf\u7a0b\u624d\u80fd\u591f\u7ee7\u7eed\u8bbf\u95ee\u8bfb\u5199\u9501\uff0c\u540c\u65f6\u524d\u6b21\u5199\u7ebf\u7a0b\u7684\u4fee\u6539\u5bf9\u540e\u7eed\u7684\u8bfb\u5199\u7ebf\u7a0b\u53ef\u89c1\u3002\n<\/p>\n<p>\n\t\u63a5\u7740\u662f\u8bfb\u9501\u7684\u4ee3\u7801\uff1a\n<\/p>\n<pre class=\"brush:java;\">\r\nprotected final int tryAcquireShared(int unused) {\r\n    Thread current = Thread.currentThread();\r\n    int c = getState();\r\n    if (exclusiveCount(c) != 0 &amp;&amp;\r\n        getExclusiveOwnerThread() != current)\r\n        return -1;    \r\n        \/\/ \u5982\u679c\u5176\u4ed6\u7ebf\u7a0b\u5df2\u7ecf\u83b7\u53d6\u4e86\u5199\u9501\uff0c\u5219\u5f53\u524d\u7ebf\u7a0b\u83b7\u53d6\u8bfb\u9501\u5931\u8d25\uff0c\u8fdb\u5165\u7b49\u5f85\u72b6\u6001                               \r\n    int r = sharedCount(c);\r\n    if (!readerShouldBlock() &amp;&amp;\r\n        r &lt; MAX_COUNT &amp;&amp;\r\n        compareAndSetState(c, c + SHARED_UNIT)) {\r\n        if (r == 0) {\r\n            firstReader = current;\r\n            firstReaderHoldCount = 1;\r\n        } else if (firstReader == current) {\r\n            firstReaderHoldCount++;\r\n        } else {\r\n            HoldCounter rh = cachedHoldCounter;\r\n            if (rh == null || rh.tid != getThreadId(current))\r\n                cachedHoldCounter = rh = readHolds.get();\r\n            else if (rh.count == 0)\r\n                readHolds.set(rh);\r\n            rh.count++;\r\n        }\r\n        return 1;\r\n    }\r\n    return fullTryAcquireShared(current);\r\n}<\/pre>\n<p>\n\t\u53ef\u4ee5\u770b\u5230\u5728 tryAcquireShared(int unused) \u65b9\u6cd5\u4e2d\uff0c\u5982\u679c\u5176\u4ed6\u7ebf\u7a0b\u5df2\u7ecf\u83b7\u53d6\u4e86\u5199\u9501\uff0c\u5219\u5f53\u524d\u7ebf\u7a0b\u83b7\u53d6\u8bfb\u9501\u5931\u8d25\uff0c\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\u3002\u5982\u679c\u5f53\u524d\u7ebf\u7a0b\u83b7\u53d6\u4e86\u5199\u9501\u6216\u8005\u5199\u9501\u672a\u88ab\u83b7\u53d6\uff0c\u5219\u5f53\u524d\u7ebf\u7a0b\uff08\u7ebf\u7a0b\u5b89\u5168\uff0c\u4f9d\u9760 CAS \u4fdd\u8bc1\uff09\u589e\u52a0\u8bfb\u72b6\u6001\uff0c\u6210\u529f\u83b7\u53d6\u8bfb\u9501\u3002\u8bfb\u9501\u7684\u6bcf\u6b21\u91ca\u653e\uff08\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u53ef\u80fd\u6709\u591a\u4e2a\u8bfb\u7ebf\u7a0b\u540c\u65f6\u91ca\u653e\u8bfb\u9501\uff09\u5747\u51cf\u5c11\u8bfb\u72b6\u6001\uff0c\u51cf\u5c11\u7684\u503c\u662f&ldquo;1&lt;&lt;16&rdquo;\u3002\u6240\u4ee5\u8bfb\u5199\u9501\u624d\u80fd\u5b9e\u73b0\u8bfb\u8bfb\u7684\u8fc7\u7a0b\u5171\u4eab\uff0c\u800c\u8bfb\u5199\u3001\u5199\u8bfb\u3001\u5199\u5199\u7684\u8fc7\u7a0b\u4e92\u65a5\u3002\n<\/p>\n<p>\n\t\u6b64\u65f6\uff0c\u6211\u4eec\u518d\u56de\u5934\u770b\u4e00\u4e0b\u4e92\u65a5\u9501 ReentrantLock \u4e2d\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u7684\u52a0\u9501\u6e90\u7801\uff1a\n<\/p>\n<p>\n\t<img decoding=\"async\" alt=\"\u4e92\u65a5\u9501ReentrantLock\u4e2d\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u7684\u52a0\u9501\u6e90\u7801\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/java-lock-cas-src-demo.png\" style=\"width: 708px;height: 353px\" \/>\n<\/p>\n<p>\n\t\u6211\u4eec\u53d1\u73b0\u5728 ReentrantLock \u867d\u7136\u6709\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u4e24\u79cd\uff0c\u4f46\u662f\u5b83\u4eec\u6dfb\u52a0\u7684\u90fd\u662f\u72ec\u4eab\u9501\u3002\u6839\u636e\u6e90\u7801\u6240\u793a\uff0c\u5f53\u67d0\u4e00\u4e2a\u7ebf\u7a0b\u8c03\u7528 lock \u65b9\u6cd5\u83b7\u53d6\u9501\u65f6\uff0c\u5982\u679c\u540c\u6b65\u8d44\u6e90\u6ca1\u6709\u88ab\u5176\u4ed6\u7ebf\u7a0b\u9501\u4f4f\uff0c\u90a3\u4e48\u5f53\u524d\u7ebf\u7a0b\u5728\u4f7f\u7528 CAS \u66f4\u65b0 state \u6210\u529f\u540e\u5c31\u4f1a\u6210\u529f\u62a2\u5360\u8be5\u8d44\u6e90\u3002\u800c\u5982\u679c\u516c\u5171\u8d44\u6e90\u88ab\u5360\u7528\u4e14\u4e0d\u662f\u88ab\u5f53\u524d\u7ebf\u7a0b\u5360\u7528\uff0c\u90a3\u4e48\u5c31\u4f1a\u52a0\u9501\u5931\u8d25\u3002\u6240\u4ee5\u53ef\u4ee5\u786e\u5b9a ReentrantLock \u65e0\u8bba\u8bfb\u64cd\u4f5c\u8fd8\u662f\u5199\u64cd\u4f5c\uff0c\u6dfb\u52a0\u7684\u9501\u90fd\u662f\u90fd\u662f\u72ec\u4eab\u9501\u3002\n<\/p>\n<p>\n\tJava \u4e2d\u7684\u5404\u79cd\u5e26\u6709\u9501\u7684\u539f\u5b50\u7c7b\n<\/p>\n<ul>\n<li>\n\t\tAtomicIntegerFieldUpdater:\u539f\u5b50\u66f4\u65b0\u6574\u578b\u7684\u5b57\u6bb5\u7684\u66f4\u65b0\u5668\n\t<\/li>\n<li>\n\t\tAtomicLongFieldUpdater\uff1a\u539f\u5b50\u66f4\u65b0\u957f\u6574\u578b\u5b57\u6bb5\u7684\u66f4\u65b0\u5668\n\t<\/li>\n<li>\n\t\tAtomicStampedReference:\u539f\u5b50\u66f4\u65b0\u5e26\u6709\u7248\u672c\u53f7\u7684\u5f15\u7528\u7c7b\u578b\u3002\u8be5\u7c7b\u5c06\u6574\u578b\u6570\u503c\u4e0e\u5f15\u7528\u5173\u8054\u8d77\u6765\uff0c\u53ef\u7528\u4e8e\u539f\u5b50\u7684\u66f4\u65b0\u6570\u636e\u548c\u6570\u636e\u7684\u7248\u672c\u53f7\uff0c\u53ef\u4ee5\u89e3\u51b3\u4f7f\u7528CAS\u8fdb\u884c\u539f\u5b50\u66f4\u65b0\u65f6\u53ef\u80fd\u51fa\u73b0\u7684ABA\u95ee\u9898\u3002\n\t<\/li>\n<li>\n\t\tAtomicReference \uff1a\u539f\u5b50\u66f4\u65b0\u5f15\u7528\u7c7b\u578b\n\t<\/li>\n<li>\n\t\tAtomicReferenceFieldUpdater \uff1a\u539f\u5b50\u66f4\u65b0\u5f15\u7528\u7c7b\u578b\u91cc\u7684\u5b57\u6bb5\n\t<\/li>\n<li>\n\t\tAtomicMarkableReference\uff1a\u539f\u5b50\u66f4\u65b0\u5e26\u6709\u6807\u8bb0\u4f4d\u7684\u5f15\u7528\u7c7b\u578b\u3002\u53ef\u4ee5\u539f\u5b50\u66f4\u65b0\u4e00\u4e2a\u5e03\u5c14\u7c7b\u578b\u7684\u6807\u8bb0\u4f4d\u548c\u5e94\u7528\u7c7b\u578b\n\t<\/li>\n<li>\n\t\tAtomicIntegerArray \uff1a\u539f\u5b50\u66f4\u65b0\u6574\u578b\u6570\u7ec4\u91cc\u7684\u5143\u7d20\n\t<\/li>\n<li>\n\t\tAtomicLongArray :\u539f\u5b50\u66f4\u65b0\u957f\u6574\u578b\u6570\u7ec4\u91cc\u7684\u5143\u7d20\n\t<\/li>\n<li>\n\t\tAtomicReferenceArray : \u539f\u5b50\u66f4\u65b0\u5f15\u7528\u7c7b\u578b\u6570\u7ec4\u7684\u5143\u7d20\n\t<\/li>\n<li>\n\t\tAtomicBooleanArray \uff1a\u539f\u5b50\u66f4\u65b0\u5e03\u5c14\u7c7b\u578b\u6570\u7ec4\u7684\u5143\u7d20\n\t<\/li>\n<li>\n\t\tAtomicBoolean \uff1a\u539f\u5b50\u66f4\u65b0\u5e03\u5c14\u7c7b\u578b\n\t<\/li>\n<li>\n\t\tAtomicInteger\uff1a \u539f\u5b50\u66f4\u65b0\u6574\u578b\n\t<\/li>\n<li>\n\t\tAtomicLong: \u539f\u5b50\u66f4\u65b0\u957f\u6574\u578b\n\t<\/li>\n<\/ul>\n<p>\n\t\u597d\u5427\uff0c\u5173\u4e8e\u9501\uff0c\u6211\u6682\u65f6\u5c31\u5148\u5199\u5230\u8fd9\u91cc\u3002Java \u4e2d\u8fd8\u6709\u5f88\u591a\u5404\u79cd\u5404\u6837\u7684\u9501\u5b9e\u73b0\u7c7b\u3002\u4ee5\u540e\uff0c\u6211\u9047\u5230\u5177\u4f53\u7684\uff0c\u5728\u7ed9\u5927\u5bb6\u4e00\u4e00\u7684\u5199\uff01<\/p>\n<!-- <audio autoplay=\"autoplay\" height=\"100\" width=\"100\" hidden=\"true\"><source src=\"https:\/\/c.coka.la\/orAvPR.mp3\" type=\"audio\/mp3\"\/><\/audio><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/ws3.sinaimg.cn\/large\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/> --><p><!-- <img decoding=\"async\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/>--><img decoding=\"async\" src=\"https:\/\/saas.51autoparts.cn\/api\/admin\/sys-file\/oss\/file?fileName=84db51f8561e448f9a4fda2eff0811f9.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/><\/p><p>\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01<b>\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1a<font color=\"red\">xttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p><p>\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a<a href=\"https:\/\/www.xttblog.com\">\u4e1a\u4f59\u8349<\/a>\uff1a &raquo; <a href=\"https:\/\/www.xttblog.com\/?p=3404\">\u4ece ReentrantReadWriteLock \u8bf4\u72ec\u4eab\u9501(\u6392\u4ed6\u9501)\u4e0e\u5171\u4eab\u9501<\/a><\/p><!-- <div class=\"bd-reward-stl\"><button id=\"bdRewardBtn\"><span><\/span><\/button><\/div> -->","protected":false},"excerpt":{"rendered":"<p>\u9605\u8bfb\u524d\u9762\u7684\u6587\u7ae0\uff0c\u6211\u4eec\u77e5\u9053 ReentrantLock \u662f\u4e00\u4e2a\u9ad8\u6548\u7684\u9501\uff0c\u5b83\u65e2\u80fd\u7528\u4f5c\u516c\u5e73\u9501\uff0c\u53c8\u80fd\u7528\u4f5c\u975e\u516c\u5e73\u9501\uff01\u4f46\u662f [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[1760,1759,712,1761,426],"class_list":["post-3404","post","type-post","status-publish","format-standard","hentry","category-java","tag-aqs","tag-nonreentrantlock","tag-reentrantlock","tag-reentrantreadwritelock","tag-synchronized"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3404","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3404"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3404\/revisions"}],"predecessor-version":[{"id":3405,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3404\/revisions\/3405"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3404"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3404"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3404"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}