{"id":158,"date":"2025-07-13T16:41:23","date_gmt":"2025-07-13T08:41:23","guid":{"rendered":"https:\/\/yingjun.run\/?p=158"},"modified":"2025-07-13T16:41:23","modified_gmt":"2025-07-13T08:41:23","slug":"java%e5%b9%b6%e5%8f%91","status":"publish","type":"post","link":"https:\/\/yingjun.run\/index.php\/2025\/07\/13\/java%e5%b9%b6%e5%8f%91\/","title":{"rendered":"Java\u5e76\u53d1"},"content":{"rendered":"<h3><span class=\"ez-toc-section\" id=\"%E4%BB%80%E4%B9%88%E6%98%AF%E7%BA%BF%E7%A8%8B%E5%92%8C%E8%BF%9B%E7%A8%8B\"><\/span>\u4ec0\u4e48\u662f\u7ebf\u7a0b\u548c\u8fdb\u7a0b?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u4f55\u4e3a\u8fdb\u7a0b?<\/strong><br \/>\n\u8fdb\u7a0b\u662f\u7a0b\u5e8f\u7684\u4e00\u6b21\u6267\u884c\u8fc7\u7a0b\uff0c\u662f\u7cfb\u7edf\u8fd0\u884c\u7a0b\u5e8f\u7684\u57fa\u672c\u5355\u4f4d\uff0c\u56e0\u6b64\u8fdb\u7a0b\u662f\u52a8\u6001\u7684\u3002\u7cfb\u7edf\u8fd0\u884c\u4e00\u4e2a\u7a0b\u5e8f\u5373\u662f\u4e00\u4e2a\u8fdb\u7a0b\u4ece\u521b\u5efa\uff0c\u8fd0\u884c\u5230\u6d88\u4ea1\u7684\u8fc7\u7a0b\u3002<\/p>\n<p>\u5728 Java \u4e2d\uff0c\u5f53\u6211\u4eec\u542f\u52a8 main \u51fd\u6570\u65f6\u5176\u5b9e\u5c31\u662f\u542f\u52a8\u4e86\u4e00\u4e2a JVM \u7684\u8fdb\u7a0b\uff0c\u800c main \u51fd\u6570\u6240\u5728\u7684\u7ebf\u7a0b\u5c31\u662f\u8fd9\u4e2a\u8fdb\u7a0b\u4e2d\u7684\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u4e5f\u79f0\u4e3b\u7ebf\u7a0b\u3002<\/p>\n<p>\u5982\u4e0b\u56fe\u6240\u793a\uff0c\u5728 Windows \u4e2d\u901a\u8fc7\u67e5\u770b\u4efb\u52a1\u7ba1\u7406\u5668\u7684\u65b9\u5f0f\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u6e05\u695a\u770b\u5230 Windows \u5f53\u524d\u8fd0\u884c\u7684\u8fdb\u7a0b\uff08.exe \u6587\u4ef6\u7684\u8fd0\u884c\uff09\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752391223341.png\" alt=\"file\" \/><\/p>\n<p><strong>\u4f55\u4e3a\u7ebf\u7a0b?<\/strong><\/p>\n<p>\u7ebf\u7a0b\u4e0e\u8fdb\u7a0b\u76f8\u4f3c\uff0c\u4f46\u7ebf\u7a0b\u662f\u4e00\u4e2a\u6bd4\u8fdb\u7a0b\u66f4\u5c0f\u7684\u6267\u884c\u5355\u4f4d\u3002\u4e00\u4e2a\u8fdb\u7a0b\u5728\u5176\u6267\u884c\u7684\u8fc7\u7a0b\u4e2d\u53ef\u4ee5\u4ea7\u751f\u591a\u4e2a\u7ebf\u7a0b\u3002\u4e0e\u8fdb\u7a0b\u4e0d\u540c\u7684\u662f\u540c\u7c7b\u7684\u591a\u4e2a\u7ebf\u7a0b\u5171\u4eab\u8fdb\u7a0b\u7684<strong>\u5806<\/strong>\u548c<strong>\u65b9\u6cd5\u533a<\/strong>\u8d44\u6e90\uff0c\u4f46\u6bcf\u4e2a\u7ebf\u7a0b\u6709\u81ea\u5df1\u7684<strong>\u7a0b\u5e8f\u8ba1\u6570\u5668\u3001\u865a\u62df\u673a\u6808\u548c\u672c\u5730\u65b9\u6cd5\u6808<\/strong>\uff0c\u6240\u4ee5\u7cfb\u7edf\u5728\u4ea7\u751f\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u6216\u662f\u5728\u5404\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u505a\u5207\u6362\u5de5\u4f5c\u65f6\uff0c\u8d1f\u62c5\u8981\u6bd4\u8fdb\u7a0b\u5c0f\u5f97\u591a\uff0c\u4e5f\u6b63\u56e0\u4e3a\u5982\u6b64\uff0c\u7ebf\u7a0b\u4e5f\u88ab\u79f0\u4e3a\u8f7b\u91cf\u7ea7\u8fdb\u7a0b\u3002<\/p>\n<p>Java \u7a0b\u5e8f\u5929\u751f\u5c31\u662f\u591a\u7ebf\u7a0b\u7a0b\u5e8f\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7 JMX \u6765\u770b\u770b\u4e00\u4e2a\u666e\u901a\u7684 Java \u7a0b\u5e8f\u6709\u54ea\u4e9b\u7ebf\u7a0b\uff0c\u4ee3\u7801\u5982\u4e0b<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class MultiThread {\n    public static void main(String[] args) {\n        \/\/ \u83b7\u53d6 Java \u7ebf\u7a0b\u7ba1\u7406 MXBean\n    ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();\n        \/\/ \u4e0d\u9700\u8981\u83b7\u53d6\u540c\u6b65\u7684 monitor \u548c synchronizer \u4fe1\u606f\uff0c\u4ec5\u83b7\u53d6\u7ebf\u7a0b\u548c\u7ebf\u7a0b\u5806\u6808\u4fe1\u606f\n        ThreadInfo[] threadInfos = threadMXBean.dumpAllThreads(false, false);\n        \/\/ \u904d\u5386\u7ebf\u7a0b\u4fe1\u606f\uff0c\u4ec5\u6253\u5370\u7ebf\u7a0b ID \u548c\u7ebf\u7a0b\u540d\u79f0\u4fe1\u606f\n        for (ThreadInfo threadInfo : threadInfos) {\n            System.out.println(&quot;[&quot; + threadInfo.getThreadId() + &quot;] &quot; + threadInfo.getThreadName());\n        }\n    }\n}\n\n\u4e0a\u8ff0\u7a0b\u5e8f\u8f93\u51fa\u5982\u4e0b\uff08\u8f93\u51fa\u5185\u5bb9\u53ef\u80fd\u4e0d\u540c\uff0c\u4e0d\u7528\u592a\u7ea0\u7ed3\u4e0b\u9762\u6bcf\u4e2a\u7ebf\u7a0b\u7684\u4f5c\u7528\uff0c\u53ea\u7528\u77e5\u9053 main \u7ebf\u7a0b\u6267\u884c main \u65b9\u6cd5\u5373\u53ef\uff09\uff1a\n\n[5] Attach Listener \/\/\u6dfb\u52a0\u4e8b\u4ef6\n[4] Signal Dispatcher \/\/ \u5206\u53d1\u5904\u7406\u7ed9 JVM \u4fe1\u53f7\u7684\u7ebf\u7a0b\n[3] Finalizer \/\/\u8c03\u7528\u5bf9\u8c61 finalize \u65b9\u6cd5\u7684\u7ebf\u7a0b\n[2] Reference Handler \/\/\u6e05\u9664 reference \u7ebf\u7a0b\n[1] main \/\/main \u7ebf\u7a0b,\u7a0b\u5e8f\u5165\u53e3<\/code><\/pre>\n<p>\u4ece\u4e0a\u9762\u7684\u8f93\u51fa\u5185\u5bb9\u53ef\u4ee5\u770b\u51fa<strong>\uff1a\u4e00\u4e2a Java \u7a0b\u5e8f\u7684\u8fd0\u884c\u662f main \u7ebf\u7a0b\u548c\u591a\u4e2a\u5176\u4ed6\u7ebf\u7a0b\u540c\u65f6\u8fd0\u884c<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E8%AF%B7%E7%AE%80%E8%A6%81%E6%8F%8F%E8%BF%B0%E7%BA%BF%E7%A8%8B%E4%B8%8E%E8%BF%9B%E7%A8%8B%E7%9A%84%E5%85%B3%E7%B3%BB%E5%8C%BA%E5%88%AB%E5%8F%8A%E4%BC%98%E7%BC%BA%E7%82%B9%EF%BC%9F\"><\/span>\u8bf7\u7b80\u8981\u63cf\u8ff0\u7ebf\u7a0b\u4e0e\u8fdb\u7a0b\u7684\u5173\u7cfb,\u533a\u522b\u53ca\u4f18\u7f3a\u70b9\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752391502991.png\" alt=\"file\" \/><\/p>\n<p>\u4ece\u4e0a\u56fe\u53ef\u4ee5\u770b\u51fa\uff1a\u4e00\u4e2a\u8fdb\u7a0b\u4e2d\u53ef\u4ee5\u6709\u591a\u4e2a\u7ebf\u7a0b\uff0c\u591a\u4e2a\u7ebf\u7a0b\u5171\u4eab\u8fdb\u7a0b\u7684<strong>\u5806\u548c\u65b9\u6cd5\u533a<\/strong> (JDK1.8 \u4e4b\u540e\u7684\u5143\u7a7a\u95f4)\u8d44\u6e90\uff0c\u4f46\u662f\u6bcf\u4e2a\u7ebf\u7a0b\u6709\u81ea\u5df1\u7684<strong>\u7a0b\u5e8f\u8ba1\u6570\u5668\u3001\u865a\u62df\u673a\u6808 \u548c \u672c\u5730\u65b9\u6cd5\u6808<\/strong>\u3002<\/p>\n<p><strong>\u603b\u7ed3\uff1a<\/strong> \u7ebf\u7a0b\u662f\u8fdb\u7a0b\u5212\u5206\u6210\u7684\u66f4\u5c0f\u7684\u8fd0\u884c\u5355\u4f4d\u3002\u7ebf\u7a0b\u548c\u8fdb\u7a0b\u6700\u5927\u7684\u4e0d\u540c\u5728\u4e8e\u57fa\u672c\u4e0a\u5404\u8fdb\u7a0b\u662f\u72ec\u7acb\u7684\uff0c\u800c\u5404\u7ebf\u7a0b\u5219\u4e0d\u4e00\u5b9a\uff0c\u56e0\u4e3a\u540c\u4e00\u8fdb\u7a0b\u4e2d\u7684\u7ebf\u7a0b\u6781\u6709\u53ef\u80fd\u4f1a\u76f8\u4e92\u5f71\u54cd\u3002\u7ebf\u7a0b\u6267\u884c\u5f00\u9500\u5c0f\uff0c\u4f46\u4e0d\u5229\u4e8e\u8d44\u6e90\u7684\u7ba1\u7406\u548c\u4fdd\u62a4\uff1b\u800c\u8fdb\u7a0b\u6b63\u76f8\u53cd\u3002<\/p>\n<p><strong>\u4e0b\u9762\u6765\u601d\u8003\u8fd9\u6837\u4e00\u4e2a\u95ee\u9898\uff1a\u4e3a\u4ec0\u4e48\u7a0b\u5e8f\u8ba1\u6570\u5668\u3001\u865a\u62df\u673a\u6808\u548c\u672c\u5730\u65b9\u6cd5\u6808\u662f\u7ebf\u7a0b\u79c1\u6709\u7684\u5462\uff1f\u4e3a\u4ec0\u4e48\u5806\u548c\u65b9\u6cd5\u533a\u662f\u7ebf\u7a0b\u5171\u4eab\u7684\u5462\uff1f<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E7%A8%8B%E5%BA%8F%E8%AE%A1%E6%95%B0%E5%99%A8%E4%B8%BA%E4%BB%80%E4%B9%88%E6%98%AF%E7%A7%81%E6%9C%89%E7%9A%84\"><\/span>\u7a0b\u5e8f\u8ba1\u6570\u5668\u4e3a\u4ec0\u4e48\u662f\u79c1\u6709\u7684?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u7a0b\u5e8f\u8ba1\u6570\u5668\u4e3b\u8981\u6709\u4e0b\u9762\u4e24\u4e2a\u4f5c\u7528\uff1a<\/strong><\/p>\n<p>1\u3001\u5b57\u8282\u7801\u89e3\u91ca\u5668\u901a\u8fc7\u6539\u53d8\u7a0b\u5e8f\u8ba1\u6570\u5668\u6765\u4f9d\u6b21\u8bfb\u53d6\u6307\u4ee4\uff0c\u4ece\u800c\u5b9e\u73b0\u4ee3\u7801\u7684\u6d41\u7a0b\u63a7\u5236\uff0c\u5982\uff1a\u987a\u5e8f\u6267\u884c\u3001\u9009\u62e9\u3001\u5faa\u73af\u3001\u5f02\u5e38\u5904\u7406\u3002<br \/>\n2\u3001\u5728\u591a\u7ebf\u7a0b\u7684\u60c5\u51b5\u4e0b\uff0c\u7a0b\u5e8f\u8ba1\u6570\u5668\u7528\u4e8e\u8bb0\u5f55\u5f53\u524d\u7ebf\u7a0b\u6267\u884c\u7684\u4f4d\u7f6e\uff0c\u4ece\u800c\u5f53\u7ebf\u7a0b\u88ab\u5207\u6362\u56de\u6765\u7684\u65f6\u5019\u80fd\u591f\u77e5\u9053\u8be5\u7ebf\u7a0b\u4e0a\u6b21\u8fd0\u884c\u5230\u54ea\u513f\u4e86\u3002<\/p>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5982\u679c\u6267\u884c\u7684\u662f native \u65b9\u6cd5\uff0c\u90a3\u4e48\u7a0b\u5e8f\u8ba1\u6570\u5668\u8bb0\u5f55\u7684\u662f undefined \u5730\u5740\uff0c\u53ea\u6709\u6267\u884c\u7684\u662f Java \u4ee3\u7801\u65f6\u7a0b\u5e8f\u8ba1\u6570\u5668\u8bb0\u5f55\u7684\u624d\u662f\u4e0b\u4e00\u6761\u6307\u4ee4\u7684\u5730\u5740\u3002<\/p>\n<p><strong>\u6240\u4ee5\uff0c\u7a0b\u5e8f\u8ba1\u6570\u5668\u79c1\u6709\u4e3b\u8981\u662f\u4e3a\u4e86\u7ebf\u7a0b\u5207\u6362\u540e\u80fd\u6062\u590d\u5230\u6b63\u786e\u7684\u6267\u884c\u4f4d\u7f6e\u3002<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E8%99%9A%E6%8B%9F%E6%9C%BA%E6%A0%88%E5%92%8C%E6%9C%AC%E5%9C%B0%E6%96%B9%E6%B3%95%E6%A0%88%E4%B8%BA%E4%BB%80%E4%B9%88%E6%98%AF%E7%A7%81%E6%9C%89%E7%9A%84\"><\/span>\u865a\u62df\u673a\u6808\u548c\u672c\u5730\u65b9\u6cd5\u6808\u4e3a\u4ec0\u4e48\u662f\u79c1\u6709\u7684?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u865a\u62df\u673a\u6808\uff1a<\/strong> \u6bcf\u4e2a Java \u65b9\u6cd5\u5728\u6267\u884c\u4e4b\u524d\u4f1a\u521b\u5efa\u4e00\u4e2a\u6808\u5e27\u7528\u4e8e\u5b58\u50a8\u5c40\u90e8\u53d8\u91cf\u8868\u3001\u64cd\u4f5c\u6570\u6808\u3001\u5e38\u91cf\u6c60\u5f15\u7528\u7b49\u4fe1\u606f\u3002\u4ece\u65b9\u6cd5\u8c03\u7528\u76f4\u81f3\u6267\u884c\u5b8c\u6210\u7684\u8fc7\u7a0b\uff0c\u5c31\u5bf9\u5e94\u7740\u4e00\u4e2a\u6808\u5e27\u5728 Java \u865a\u62df\u673a\u6808\u4e2d\u5165\u6808\u548c\u51fa\u6808\u7684\u8fc7\u7a0b\u3002<\/p>\n<p><strong>\u672c\u5730\u65b9\u6cd5\u6808\uff1a<\/strong> \u548c\u865a\u62df\u673a\u6808\u6240\u53d1\u6325\u7684\u4f5c\u7528\u975e\u5e38\u76f8\u4f3c\uff0c\u533a\u522b\u662f<strong>\uff1a\u865a\u62df\u673a\u6808\u4e3a\u865a\u62df\u673a\u6267\u884c Java \u65b9\u6cd5 \uff08\u4e5f\u5c31\u662f\u5b57\u8282\u7801\uff09\u670d\u52a1\uff0c\u800c\u672c\u5730\u65b9\u6cd5\u6808\u5219\u4e3a\u865a\u62df\u673a\u4f7f\u7528\u5230\u7684 Native \u65b9\u6cd5\u670d\u52a1<\/strong>\u3002 \u5728 HotSpot \u865a\u62df\u673a\u4e2d\u548c Java \u865a\u62df\u673a\u6808\u5408\u4e8c\u4e3a\u4e00\u3002<\/p>\n<p><strong>\u6240\u4ee5\uff0c\u4e3a\u4e86\u4fdd\u8bc1\u7ebf\u7a0b\u4e2d\u7684\u5c40\u90e8\u53d8\u91cf\u4e0d\u88ab\u522b\u7684\u7ebf\u7a0b\u8bbf\u95ee\u5230\uff0c\u865a\u62df\u673a\u6808\u548c\u672c\u5730\u65b9\u6cd5\u6808\u662f\u7ebf\u7a0b\u79c1\u6709\u7684\u3002<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%80%E5%8F%A5%E8%AF%9D%E7%AE%80%E5%8D%95%E4%BA%86%E8%A7%A3%E5%A0%86%E5%92%8C%E6%96%B9%E6%B3%95%E5%8C%BA\"><\/span>\u4e00\u53e5\u8bdd\u7b80\u5355\u4e86\u89e3\u5806\u548c\u65b9\u6cd5\u533a<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5806\u548c\u65b9\u6cd5\u533a\u662f\u6240\u6709\u7ebf\u7a0b\u5171\u4eab\u7684\u8d44\u6e90\uff0c\u5176\u4e2d\u5806\u662f\u8fdb\u7a0b\u4e2d\u6700\u5927\u7684\u4e00\u5757\u5185\u5b58\uff0c\u4e3b\u8981\u7528\u4e8e\u5b58\u653e\u65b0\u521b\u5efa\u7684\u5bf9\u8c61 (\u51e0\u4e4e\u6240\u6709\u5bf9\u8c61\u90fd\u5728\u8fd9\u91cc\u5206\u914d\u5185\u5b58)\uff0c\u65b9\u6cd5\u533a\u4e3b\u8981\u7528\u4e8e\u5b58\u653e\u5df2\u88ab\u52a0\u8f7d\u7684\u7c7b\u4fe1\u606f\u3001\u5e38\u91cf\u3001\u9759\u6001\u53d8\u91cf\u3001\u5373\u65f6\u7f16\u8bd1\u5668\u7f16\u8bd1\u540e\u7684\u4ee3\u7801\u7b49\u6570\u636e\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E5%88%9B%E5%BB%BA%E7%BA%BF%E7%A8%8B%EF%BC%9F\"><\/span>\u5982\u4f55\u521b\u5efa\u7ebf\u7a0b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u4e00\u822c\u6765\u8bf4\uff0c\u521b\u5efa\u7ebf\u7a0b\u6709\u5f88\u591a\u79cd\u65b9\u5f0f\uff0c\u4f8b\u5982\u7ee7\u627fThread\u7c7b\u3001\u5b9e\u73b0Runnable\u63a5\u53e3\u3001\u5b9e\u73b0Callable\u63a5\u53e3\u3001\u4f7f\u7528\u7ebf\u7a0b\u6c60\u3001\u4f7f\u7528CompletableFuture\u7c7b\u7b49\u7b49\u3002<\/p>\n<p>\u4e0d\u8fc7\uff0c\u8fd9\u4e9b\u65b9\u5f0f\u5176\u5b9e\u5e76\u6ca1\u6709\u771f\u6b63\u521b\u5efa\u51fa\u7ebf\u7a0b\u3002\u51c6\u786e\u70b9\u6765\u8bf4\uff0c\u8fd9\u4e9b\u90fd\u5c5e\u4e8e\u662f\u5728 Java \u4ee3\u7801\u4e2d\u4f7f\u7528\u591a\u7ebf\u7a0b\u7684\u65b9\u6cd5\u3002<\/p>\n<p>\u4e25\u683c\u6765\u8bf4\uff0cJava \u5c31\u53ea\u6709\u4e00\u79cd\u65b9\u5f0f\u53ef\u4ee5\u521b\u5efa\u7ebf\u7a0b\uff0c\u90a3\u5c31\u662f\u901a\u8fc7new Thread().start()\u521b\u5efa\u3002\u4e0d\u7ba1\u662f\u54ea\u79cd\u65b9\u5f0f\uff0c\u6700\u7ec8\u8fd8\u662f\u4f9d\u8d56\u4e8enew Thread().start()\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E8%AF%B4%E8%AF%B4%E7%BA%BF%E7%A8%8B%E7%9A%84%E7%94%9F%E5%91%BD%E5%91%A8%E6%9C%9F%E5%92%8C%E7%8A%B6%E6%80%81\"><\/span>\u8bf4\u8bf4\u7ebf\u7a0b\u7684\u751f\u547d\u5468\u671f\u548c\u72b6\u6001?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Java \u7ebf\u7a0b\u5728\u8fd0\u884c\u7684\u751f\u547d\u5468\u671f\u4e2d\u7684\u6307\u5b9a\u65f6\u523b\u53ea\u53ef\u80fd\u5904\u4e8e\u4e0b\u9762 6 \u79cd\u4e0d\u540c\u72b6\u6001\u7684\u5176\u4e2d\u4e00\u4e2a\u72b6\u6001\uff1a<\/strong><\/p>\n<p><strong>NEW:<\/strong> \u521d\u59cb\u72b6\u6001\uff0c\u7ebf\u7a0b\u88ab\u521b\u5efa\u51fa\u6765\u4f46\u6ca1\u6709\u88ab\u8c03\u7528 start() \u3002<br \/>\n<strong>RUNNABLE<\/strong>: \u8fd0\u884c\u72b6\u6001\uff0c\u7ebf\u7a0b\u88ab\u8c03\u7528\u4e86 start()\u7b49\u5f85\u8fd0\u884c\u7684\u72b6\u6001\u3002<br \/>\n<strong>BLOCKED<\/strong>\uff1a\u963b\u585e\u72b6\u6001\uff0c\u9700\u8981\u7b49\u5f85\u9501\u91ca\u653e\u3002<br \/>\n<strong>WAITING<\/strong>\uff1a\u7b49\u5f85\u72b6\u6001\uff0c\u8868\u793a\u8be5\u7ebf\u7a0b\u9700\u8981\u7b49\u5f85\u5176\u4ed6\u7ebf\u7a0b\u505a\u51fa\u4e00\u4e9b\u7279\u5b9a\u52a8\u4f5c\uff08\u901a\u77e5\u6216\u4e2d\u65ad\uff09\u3002<br \/>\n<strong>TIME_WAITING<\/strong>\uff1a\u8d85\u65f6\u7b49\u5f85\u72b6\u6001\uff0c\u53ef\u4ee5\u5728\u6307\u5b9a\u7684\u65f6\u95f4\u540e\u81ea\u884c\u8fd4\u56de\u800c\u4e0d\u662f\u50cf WAITING \u90a3\u6837\u4e00\u76f4\u7b49\u5f85\u3002<br \/>\n<strong>TERMINATED<\/strong>\uff1a\u7ec8\u6b62\u72b6\u6001\uff0c\u8868\u793a\u8be5\u7ebf\u7a0b\u5df2\u7ecf\u8fd0\u884c\u5b8c\u6bd5\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752391920585.png\" alt=\"file\" \/><\/p>\n<p>\u7531\u4e0a\u56fe\u53ef\u4ee5\u770b\u51fa\uff1a\u7ebf\u7a0b\u521b\u5efa\u4e4b\u540e\u5b83\u5c06\u5904\u4e8e<strong> NEW\uff08\u65b0\u5efa\uff09 \u72b6\u6001<\/strong>\uff0c\u8c03\u7528 start() \u65b9\u6cd5\u540e\u5f00\u59cb\u8fd0\u884c\uff0c\u7ebf\u7a0b\u8fd9\u65f6\u5019\u5904\u4e8e <strong>READY\uff08\u53ef\u8fd0\u884c\uff09<\/strong> \u72b6\u6001\u3002\u53ef\u8fd0\u884c\u72b6\u6001\u7684\u7ebf\u7a0b\u83b7\u5f97\u4e86 CPU \u65f6\u95f4\u7247\uff08timeslice\uff09\u540e\u5c31\u5904\u4e8e <strong>RUNNING\uff08\u8fd0\u884c\uff09<\/strong> \u72b6\u6001\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%BB%80%E4%B9%88%E6%98%AF%E7%BA%BF%E7%A8%8B%E4%B8%8A%E4%B8%8B%E6%96%87%E5%88%87%E6%8D%A2\"><\/span>\u4ec0\u4e48\u662f\u7ebf\u7a0b\u4e0a\u4e0b\u6587\u5207\u6362?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u7ebf\u7a0b\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d\u4f1a\u6709\u81ea\u5df1\u7684\u8fd0\u884c\u6761\u4ef6\u548c\u72b6\u6001\uff08\u4e5f\u79f0\u4e0a\u4e0b\u6587\uff09\uff0c\u6bd4\u5982\u4e0a\u6587\u6240\u8bf4\u5230\u8fc7\u7684\u7a0b\u5e8f\u8ba1\u6570\u5668\uff0c\u6808\u4fe1\u606f\u7b49\u3002\u5f53\u51fa\u73b0\u5982\u4e0b\u60c5\u51b5\u7684\u65f6\u5019\uff0c\u7ebf\u7a0b\u4f1a\u4ece\u5360\u7528 CPU \u72b6\u6001\u4e2d\u9000\u51fa\u3002<\/p>\n<p>1\u3001\u4e3b\u52a8\u8ba9\u51fa CPU\uff0c\u6bd4\u5982\u8c03\u7528\u4e86 sleep(), wait() \u7b49\u3002<br \/>\n2\u3001\u65f6\u95f4\u7247\u7528\u5b8c\uff0c\u56e0\u4e3a\u64cd\u4f5c\u7cfb\u7edf\u8981\u9632\u6b62\u4e00\u4e2a\u7ebf\u7a0b\u6216\u8005\u8fdb\u7a0b\u957f\u65f6\u95f4\u5360\u7528 CPU \u5bfc\u81f4\u5176\u4ed6\u7ebf\u7a0b\u6216\u8005\u8fdb\u7a0b\u997f\u6b7b\u3002<br \/>\n3\u3001\u8c03\u7528\u4e86\u963b\u585e\u7c7b\u578b\u7684\u7cfb\u7edf\u4e2d\u65ad\uff0c\u6bd4\u5982\u8bf7\u6c42 IO\uff0c\u7ebf\u7a0b\u88ab\u963b\u585e\u3002<br \/>\n4\u3001\u88ab\u7ec8\u6b62\u6216\u7ed3\u675f\u8fd0\u884c<\/p>\n<p>\u8fd9\u5176\u4e2d\u524d\u4e09\u79cd\u90fd\u4f1a\u53d1\u751f\u7ebf\u7a0b\u5207\u6362\uff0c\u7ebf\u7a0b\u5207\u6362\u610f\u5473\u7740\u9700\u8981\u4fdd\u5b58\u5f53\u524d\u7ebf\u7a0b\u7684\u4e0a\u4e0b\u6587\uff0c\u7559\u5f85\u7ebf\u7a0b\u4e0b\u6b21\u5360\u7528 CPU \u7684\u65f6\u5019\u6062\u590d\u73b0\u573a\u3002\u5e76\u52a0\u8f7d\u4e0b\u4e00\u4e2a\u5c06\u8981\u5360\u7528 CPU \u7684\u7ebf\u7a0b\u4e0a\u4e0b\u6587\u3002\u8fd9\u5c31\u662f\u6240\u8c13\u7684 <strong>\u4e0a\u4e0b\u6587\u5207\u6362\u3002<\/strong><\/p>\n<p>\u4e0a\u4e0b\u6587\u5207\u6362\u662f\u73b0\u4ee3\u64cd\u4f5c\u7cfb\u7edf\u7684\u57fa\u672c\u529f\u80fd\uff0c\u56e0\u5176\u6bcf\u6b21\u9700\u8981\u4fdd\u5b58\u4fe1\u606f\u6062\u590d\u4fe1\u606f\uff0c\u8fd9\u5c06\u4f1a\u5360\u7528 CPU\uff0c\u5185\u5b58\u7b49\u7cfb\u7edf\u8d44\u6e90\u8fdb\u884c\u5904\u7406\uff0c\u4e5f\u5c31\u610f\u5473\u7740\u6548\u7387\u4f1a\u6709\u4e00\u5b9a\u635f\u8017\uff0c\u5982\u679c\u9891\u7e41\u5207\u6362\u5c31\u4f1a\u9020\u6210\u6574\u4f53\u6548\u7387\u4f4e\u4e0b<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Threadsleep_%E6%96%B9%E6%B3%95%E5%92%8C_Objectwait_%E6%96%B9%E6%B3%95%E5%AF%B9%E6%AF%94\"><\/span>Thread#sleep() \u65b9\u6cd5\u548c Object#wait() \u65b9\u6cd5\u5bf9\u6bd4<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u5171\u540c\u70b9<\/strong>\uff1a\u4e24\u8005\u90fd\u53ef\u4ee5\u6682\u505c\u7ebf\u7a0b\u7684\u6267\u884c\u3002<\/p>\n<p><strong>\u533a\u522b\uff1a<\/strong><br \/>\n<strong>sleep() \u65b9\u6cd5\u6ca1\u6709\u91ca\u653e\u9501\uff0c\u800c wait() \u65b9\u6cd5\u91ca\u653e\u4e86\u9501 <\/strong>\u3002<br \/>\nwait() \u901a\u5e38\u88ab\u7528\u4e8e\u7ebf\u7a0b\u95f4\u4ea4\u4e92\/\u901a\u4fe1\uff0csleep()\u901a\u5e38\u88ab\u7528\u4e8e\u6682\u505c\u6267\u884c\u3002<br \/>\nwait() \u65b9\u6cd5\u88ab\u8c03\u7528\u540e\uff0c\u7ebf\u7a0b\u4e0d\u4f1a\u81ea\u52a8\u82cf\u9192\uff0c\u9700\u8981\u522b\u7684\u7ebf\u7a0b\u8c03\u7528\u540c\u4e00\u4e2a\u5bf9\u8c61\u4e0a\u7684 notify()\u6216\u8005 notifyAll() \u65b9\u6cd5\u3002sleep()\u65b9\u6cd5\u6267\u884c\u5b8c\u6210\u540e\uff0c\u7ebf\u7a0b\u4f1a\u81ea\u52a8\u82cf\u9192\uff0c\u6216\u8005\u4e5f\u53ef\u4ee5\u4f7f\u7528 wait(long timeout) \u8d85\u65f6\u540e\u7ebf\u7a0b\u4f1a\u81ea\u52a8\u82cf\u9192\u3002<br \/>\nsleep() \u662f Thread \u7c7b\u7684\u9759\u6001\u672c\u5730\u65b9\u6cd5\uff0cwait() \u5219\u662f Object \u7c7b\u7684\u672c\u5730\u65b9\u6cd5\u3002\u4e3a\u4ec0\u4e48\u8fd9\u6837\u8bbe\u8ba1\u5462\uff1f\u4e0b\u4e00\u4e2a\u95ee\u9898\u5c31\u4f1a\u804a\u5230\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88_wait_%E6%96%B9%E6%B3%95%E4%B8%8D%E5%AE%9A%E4%B9%89%E5%9C%A8_Thread_%E4%B8%AD%EF%BC%9F\"><\/span>\u4e3a\u4ec0\u4e48 wait() \u65b9\u6cd5\u4e0d\u5b9a\u4e49\u5728 Thread \u4e2d\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>wait() \u662f\u8ba9\u83b7\u5f97\u5bf9\u8c61\u9501\u7684\u7ebf\u7a0b\u5b9e\u73b0\u7b49\u5f85\uff0c\u4f1a\u81ea\u52a8\u91ca\u653e\u5f53\u524d\u7ebf\u7a0b\u5360\u6709\u7684\u5bf9\u8c61\u9501\u3002\u6bcf\u4e2a\u5bf9\u8c61\uff08Object\uff09\u90fd\u62e5\u6709\u5bf9\u8c61\u9501\uff0c\u65e2\u7136\u8981\u91ca\u653e\u5f53\u524d\u7ebf\u7a0b\u5360\u6709\u7684\u5bf9\u8c61\u9501\u5e76\u8ba9\u5176\u8fdb\u5165 WAITING \u72b6\u6001\uff0c\u81ea\u7136\u662f\u8981\u64cd\u4f5c\u5bf9\u5e94\u7684\u5bf9\u8c61\uff08Object\uff09\u800c\u975e\u5f53\u524d\u7684\u7ebf\u7a0b\uff08Thread\uff09\u3002<\/p>\n<p>\u7c7b\u4f3c\u7684\u95ee\u9898\uff1a<strong>\u4e3a\u4ec0\u4e48 sleep() \u65b9\u6cd5\u5b9a\u4e49\u5728 Thread \u4e2d\uff1f<\/strong><\/p>\n<p>\u56e0\u4e3a sleep() \u662f\u8ba9\u5f53\u524d\u7ebf\u7a0b\u6682\u505c\u6267\u884c\uff0c\u4e0d\u6d89\u53ca\u5230\u5bf9\u8c61\u7c7b\uff0c\u4e5f\u4e0d\u9700\u8981\u83b7\u5f97\u5bf9\u8c61\u9501\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%8F%AF%E4%BB%A5%E7%9B%B4%E6%8E%A5%E8%B0%83%E7%94%A8_Thread_%E7%B1%BB%E7%9A%84_run_%E6%96%B9%E6%B3%95%E5%90%97%EF%BC%9F\"><\/span>\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528 Thread \u7c7b\u7684 run \u65b9\u6cd5\u5417\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>new \u4e00\u4e2a Thread\uff0c\u7ebf\u7a0b\u8fdb\u5165\u4e86\u65b0\u5efa\u72b6\u6001\u3002\u8c03\u7528 start()\u65b9\u6cd5\uff0c\u4f1a\u542f\u52a8\u4e00\u4e2a\u7ebf\u7a0b\u5e76\u4f7f\u7ebf\u7a0b\u8fdb\u5165\u4e86\u5c31\u7eea\u72b6\u6001\uff0c\u5f53\u5206\u914d\u5230\u65f6\u95f4\u7247\u540e\u5c31\u53ef\u4ee5\u5f00\u59cb\u8fd0\u884c\u4e86\u3002 start() \u4f1a\u6267\u884c\u7ebf\u7a0b\u7684\u76f8\u5e94\u51c6\u5907\u5de5\u4f5c\uff0c\u7136\u540e\u81ea\u52a8\u6267\u884c run() \u65b9\u6cd5\u7684\u5185\u5bb9\uff0c\u8fd9\u662f\u771f\u6b63\u7684\u591a\u7ebf\u7a0b\u5de5\u4f5c\u3002 \u4f46\u662f\uff0c\u76f4\u63a5\u6267\u884c run() \u65b9\u6cd5\uff0c\u4f1a\u628a run() \u65b9\u6cd5\u5f53\u6210\u4e00\u4e2a main \u7ebf\u7a0b\u4e0b\u7684\u666e\u901a\u65b9\u6cd5\u53bb\u6267\u884c\uff0c\u5e76\u4e0d\u4f1a\u5728\u67d0\u4e2a\u7ebf\u7a0b\u4e2d\u6267\u884c\u5b83\uff0c\u6240\u4ee5\u8fd9\u5e76\u4e0d\u662f\u591a\u7ebf\u7a0b\u5de5\u4f5c\u3002<\/p>\n<p><strong>\u603b\u7ed3\uff1a\u8c03\u7528 start() \u65b9\u6cd5\u65b9\u53ef\u542f\u52a8\u7ebf\u7a0b\u5e76\u4f7f\u7ebf\u7a0b\u8fdb\u5165\u5c31\u7eea\u72b6\u6001\uff0c\u76f4\u63a5\u6267\u884c run() \u65b9\u6cd5\u7684\u8bdd\u4e0d\u4f1a\u4ee5\u591a\u7ebf\u7a0b\u7684\u65b9\u5f0f\u6267\u884c<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A4%9A%E7%BA%BF%E7%A8%8B\"><\/span>\u591a\u7ebf\u7a0b<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"%E5%B9%B6%E5%8F%91%E4%B8%8E%E5%B9%B6%E8%A1%8C%E7%9A%84%E5%8C%BA%E5%88%AB\"><\/span>\u5e76\u53d1\u4e0e\u5e76\u884c\u7684\u533a\u522b<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5e76\u53d1\uff1a\u4e24\u4e2a\u53ca\u4e24\u4e2a\u4ee5\u4e0a\u7684\u4f5c\u4e1a\u5728\u540c\u4e00 \u65f6\u95f4\u6bb5 \u5185\u6267\u884c\u3002<br \/>\n\u5e76\u884c\uff1a\u4e24\u4e2a\u53ca\u4e24\u4e2a\u4ee5\u4e0a\u7684\u4f5c\u4e1a\u5728\u540c\u4e00 \u65f6\u523b \u6267\u884c\u3002<br \/>\n\u6700\u5173\u952e\u7684\u70b9\u662f\uff1a\u662f\u5426\u662f <strong>\u540c\u65f6<\/strong> \u6267\u884c\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88%E8%A6%81%E4%BD%BF%E7%94%A8%E5%A4%9A%E7%BA%BF%E7%A8%8B\"><\/span>\u4e3a\u4ec0\u4e48\u8981\u4f7f\u7528\u591a\u7ebf\u7a0b?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5148\u4ece\u603b\u4f53\u4e0a\u6765\u8bf4\uff1a<br \/>\n<strong>\u4ece\u8ba1\u7b97\u673a\u5e95\u5c42\u6765\u8bf4\uff1a<\/strong> \u7ebf\u7a0b\u53ef\u4ee5\u6bd4\u4f5c\u662f\u8f7b\u91cf\u7ea7\u7684\u8fdb\u7a0b\uff0c\u662f\u7a0b\u5e8f\u6267\u884c\u7684\u6700\u5c0f\u5355\u4f4d\uff0c\u7ebf\u7a0b\u95f4\u7684\u5207\u6362\u548c\u8c03\u5ea6\u7684\u6210\u672c\u8fdc\u8fdc\u5c0f\u4e8e\u8fdb\u7a0b\u3002\u53e6\u5916\uff0c\u591a\u6838 CPU \u65f6\u4ee3\u610f\u5473\u7740\u591a\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u540c\u65f6\u8fd0\u884c\uff0c\u8fd9\u51cf\u5c11\u4e86\u7ebf\u7a0b\u4e0a\u4e0b\u6587\u5207\u6362\u7684\u5f00\u9500\u3002<\/p>\n<p><strong>\u4ece\u5f53\u4ee3\u4e92\u8054\u7f51\u53d1\u5c55\u8d8b\u52bf\u6765\u8bf4<\/strong>\uff1a \u73b0\u5728\u7684\u7cfb\u7edf\u52a8\u4e0d\u52a8\u5c31\u8981\u6c42\u767e\u4e07\u7ea7\u751a\u81f3\u5343\u4e07\u7ea7\u7684\u5e76\u53d1\u91cf\uff0c\u800c\u591a\u7ebf\u7a0b\u5e76\u53d1\u7f16\u7a0b\u6b63\u662f\u5f00\u53d1\u9ad8\u5e76\u53d1\u7cfb\u7edf\u7684\u57fa\u7840\uff0c\u5229\u7528\u597d\u591a\u7ebf\u7a0b\u673a\u5236\u53ef\u4ee5\u5927\u5927\u63d0\u9ad8\u7cfb\u7edf\u6574\u4f53\u7684\u5e76\u53d1\u80fd\u529b\u4ee5\u53ca\u6027\u80fd\u3002<\/p>\n<p>\u518d\u6df1\u5165\u5230\u8ba1\u7b97\u673a\u5e95\u5c42\u6765\u63a2\u8ba8\uff1a<\/p>\n<p><strong>\u5355\u6838\u65f6\u4ee3\uff1a<\/strong>\u5728\u5355\u6838\u65f6\u4ee3\u591a\u7ebf\u7a0b\u4e3b\u8981\u662f\u4e3a\u4e86\u63d0\u9ad8\u5355\u8fdb\u7a0b\u5229\u7528 CPU \u548c IO \u7cfb\u7edf\u7684\u6548\u7387\u3002 \u5047\u8bbe\u53ea\u8fd0\u884c\u4e86\u4e00\u4e2a Java \u8fdb\u7a0b\u7684\u60c5\u51b5\uff0c\u5f53\u6211\u4eec\u8bf7\u6c42 IO \u7684\u65f6\u5019\uff0c\u5982\u679c Java \u8fdb\u7a0b\u4e2d\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u6b64\u7ebf\u7a0b\u88ab IO \u963b\u585e\u5219\u6574\u4e2a\u8fdb\u7a0b\u88ab\u963b\u585e\u3002CPU \u548c IO \u8bbe\u5907\u53ea\u6709\u4e00\u4e2a\u5728\u8fd0\u884c\uff0c\u90a3\u4e48\u53ef\u4ee5\u7b80\u5355\u5730\u8bf4\u7cfb\u7edf\u6574\u4f53\u6548\u7387\u53ea\u6709 50%\u3002\u5f53\u4f7f\u7528\u591a\u7ebf\u7a0b\u7684\u65f6\u5019\uff0c\u4e00\u4e2a\u7ebf\u7a0b\u88ab IO \u963b\u585e\uff0c\u5176\u4ed6\u7ebf\u7a0b\u8fd8\u53ef\u4ee5\u7ee7\u7eed\u4f7f\u7528 CPU\u3002\u4ece\u800c\u63d0\u9ad8\u4e86 Java \u8fdb\u7a0b\u5229\u7528\u7cfb\u7edf\u8d44\u6e90\u7684\u6574\u4f53\u6548\u7387\u3002<\/p>\n<p><strong>\u591a\u6838\u65f6\u4ee3:<\/strong> \u591a\u6838\u65f6\u4ee3\u591a\u7ebf\u7a0b\u4e3b\u8981\u662f\u4e3a\u4e86\u63d0\u9ad8\u8fdb\u7a0b\u5229\u7528\u591a\u6838 CPU \u7684\u80fd\u529b\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff1a\u5047\u5982\u6211\u4eec\u8981\u8ba1\u7b97\u4e00\u4e2a\u590d\u6742\u7684\u4efb\u52a1\uff0c\u6211\u4eec\u53ea\u7528\u4e00\u4e2a\u7ebf\u7a0b\u7684\u8bdd\uff0c\u4e0d\u8bba\u7cfb\u7edf\u6709\u51e0\u4e2a CPU \u6838\u5fc3\uff0c\u90fd\u53ea\u4f1a\u6709\u4e00\u4e2a CPU \u6838\u5fc3\u88ab\u5229\u7528\u5230\u3002\u800c\u521b\u5efa\u591a\u4e2a\u7ebf\u7a0b\uff0c\u8fd9\u4e9b\u7ebf\u7a0b\u53ef\u4ee5\u88ab\u6620\u5c04\u5230\u5e95\u5c42\u591a\u4e2a CPU \u6838\u5fc3\u4e0a\u6267\u884c\uff0c\u5728\u4efb\u52a1\u4e2d\u7684\u591a\u4e2a\u7ebf\u7a0b\u6ca1\u6709\u8d44\u6e90\u7ade\u4e89\u7684\u60c5\u51b5\u4e0b\uff0c\u4efb\u52a1\u6267\u884c\u7684\u6548\u7387\u4f1a\u6709\u663e\u8457\u6027\u7684\u63d0\u9ad8\uff0c\u7ea6\u7b49\u4e8e\uff08\u5355\u6838\u65f6\u6267\u884c\u65f6\u95f4\/CPU \u6838\u5fc3\u6570\uff09\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%8D%95%E6%A0%B8_CPU_%E6%94%AF%E6%8C%81_Java_%E5%A4%9A%E7%BA%BF%E7%A8%8B%E5%90%97%EF%BC%9F\"><\/span>\u5355\u6838 CPU \u652f\u6301 Java \u591a\u7ebf\u7a0b\u5417\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5355\u6838 CPU \u662f\u652f\u6301 Java \u591a\u7ebf\u7a0b\u7684\u3002\u64cd\u4f5c\u7cfb\u7edf\u901a\u8fc7\u65f6\u95f4\u7247\u8f6e\u8f6c\u7684\u65b9\u5f0f\uff0c\u5c06 CPU \u7684\u65f6\u95f4\u5206\u914d\u7ed9\u4e0d\u540c\u7684\u7ebf\u7a0b\u3002\u5c3d\u7ba1\u5355\u6838 CPU \u4e00\u6b21\u53ea\u80fd\u6267\u884c\u4e00\u4e2a\u4efb\u52a1\uff0c\u4f46\u901a\u8fc7\u5feb\u901f\u5728\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u5207\u6362\uff0c\u53ef\u4ee5\u8ba9\u7528\u6237\u611f\u89c9\u591a\u4e2a\u4efb\u52a1\u662f\u540c\u65f6\u8fdb\u884c\u7684\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%8D%95%E6%A0%B8_CPU_%E4%B8%8A%E8%BF%90%E8%A1%8C%E5%A4%9A%E4%B8%AA%E7%BA%BF%E7%A8%8B%E6%95%88%E7%8E%87%E4%B8%80%E5%AE%9A%E4%BC%9A%E9%AB%98%E5%90%97%EF%BC%9F\"><\/span>\u5355\u6838 CPU \u4e0a\u8fd0\u884c\u591a\u4e2a\u7ebf\u7a0b\u6548\u7387\u4e00\u5b9a\u4f1a\u9ad8\u5417\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5355\u6838 CPU \u540c\u65f6\u8fd0\u884c\u591a\u4e2a\u7ebf\u7a0b\u7684\u6548\u7387\u662f\u5426\u4f1a\u9ad8\uff0c\u53d6\u51b3\u4e8e\u7ebf\u7a0b\u7684\u7c7b\u578b\u548c\u4efb\u52a1\u7684\u6027\u8d28\u3002\u4e00\u822c\u6765\u8bf4\uff0c\u6709\u4e24\u79cd\u7c7b\u578b\u7684\u7ebf\u7a0b\uff1a<\/p>\n<p><strong>CPU \u5bc6\u96c6\u578b<\/strong>\uff1aCPU \u5bc6\u96c6\u578b\u7684\u7ebf\u7a0b\u4e3b\u8981\u8fdb\u884c\u8ba1\u7b97\u548c\u903b\u8f91\u5904\u7406\uff0c\u9700\u8981\u5360\u7528\u5927\u91cf\u7684 CPU \u8d44\u6e90\u3002<br \/>\n<strong>IO \u5bc6\u96c6\u578b<\/strong>\uff1aIO \u5bc6\u96c6\u578b\u7684\u7ebf\u7a0b\u4e3b\u8981\u8fdb\u884c\u8f93\u5165\u8f93\u51fa\u64cd\u4f5c\uff0c\u5982\u8bfb\u5199\u6587\u4ef6\u3001\u7f51\u7edc\u901a\u4fe1\u7b49\uff0c\u9700\u8981\u7b49\u5f85 IO \u8bbe\u5907\u7684\u54cd\u5e94\uff0c\u800c\u4e0d\u5360\u7528\u592a\u591a\u7684 CPU \u8d44\u6e90<\/p>\n<p>\u5728\u5355\u6838 CPU \u4e0a\uff0c\u540c\u4e00\u65f6\u523b\u53ea\u80fd\u6709\u4e00\u4e2a\u7ebf\u7a0b\u5728\u8fd0\u884c\uff0c\u5176\u4ed6\u7ebf\u7a0b\u9700\u8981\u7b49\u5f85 CPU \u7684\u65f6\u95f4\u7247\u5206\u914d\u3002\u5982\u679c\u7ebf\u7a0b\u662f CPU \u5bc6\u96c6\u578b\u7684\uff0c\u90a3\u4e48\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u8fd0\u884c\u4f1a\u5bfc\u81f4\u9891\u7e41\u7684\u7ebf\u7a0b\u5207\u6362\uff0c\u589e\u52a0\u4e86\u7cfb\u7edf\u7684\u5f00\u9500\uff0c\u964d\u4f4e\u4e86\u6548\u7387\u3002\u5982\u679c\u7ebf\u7a0b\u662f IO \u5bc6\u96c6\u578b\u7684\uff0c\u90a3\u4e48\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u8fd0\u884c\u53ef\u4ee5\u5229\u7528 CPU \u5728\u7b49\u5f85 IO \u65f6\u7684\u7a7a\u95f2\u65f6\u95f4\uff0c\u63d0\u9ad8\u4e86\u6548\u7387\u3002<\/p>\n<p>\u56e0\u6b64\uff0c\u5bf9\u4e8e\u5355\u6838 CPU \u6765\u8bf4\uff0c\u5982\u679c\u4efb\u52a1\u662f CPU \u5bc6\u96c6\u578b\u7684\uff0c\u90a3\u4e48\u5f00\u5f88\u591a\u7ebf\u7a0b\u4f1a\u5f71\u54cd\u6548\u7387\uff1b\u5982\u679c\u4efb\u52a1\u662f IO \u5bc6\u96c6\u578b\u7684\uff0c\u90a3\u4e48\u5f00\u5f88\u591a\u7ebf\u7a0b\u4f1a\u63d0\u9ad8\u6548\u7387\u3002\u5f53\u7136\uff0c\u8fd9\u91cc\u7684\u201c\u5f88\u591a\u201d\u4e5f\u8981\u9002\u5ea6\uff0c\u4e0d\u80fd\u8d85\u8fc7\u7cfb\u7edf\u80fd\u591f\u627f\u53d7\u7684\u4e0a\u9650\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%BB%80%E4%B9%88%E6%98%AF%E7%BA%BF%E7%A8%8B%E6%AD%BB%E9%94%81%EF%BC%9F\"><\/span>\u4ec0\u4e48\u662f\u7ebf\u7a0b\u6b7b\u9501\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u7ebf\u7a0b\u6b7b\u9501\u63cf\u8ff0\u7684\u662f\u8fd9\u6837\u4e00\u79cd\u60c5\u51b5\uff1a\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u88ab\u963b\u585e\uff0c\u5b83\u4eec\u4e2d\u7684\u4e00\u4e2a\u6216\u8005\u5168\u90e8\u90fd\u5728\u7b49\u5f85\u67d0\u4e2a\u8d44\u6e90\u88ab\u91ca\u653e\u3002\u7531\u4e8e\u7ebf\u7a0b\u88ab\u65e0\u9650\u671f\u5730\u963b\u585e\uff0c\u56e0\u6b64\u7a0b\u5e8f\u4e0d\u53ef\u80fd\u6b63\u5e38\u7ec8\u6b62\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752393588988.png\" alt=\"file\" \/><\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class DeadLockDemo {\n    private static Object resource1 = new Object();\/\/\u8d44\u6e90 1\n    private static Object resource2 = new Object();\/\/\u8d44\u6e90 2\n\n    public static void main(String[] args) {\n        new Thread(() -&gt; {\n            synchronized (resource1) {\n                System.out.println(Thread.currentThread() + &quot;get resource1&quot;);\n                try {\n                    Thread.sleep(1000);\n                } catch (InterruptedException e) {\n                    e.printStackTrace();\n                }\n                System.out.println(Thread.currentThread() + &quot;waiting get resource2&quot;);\n                synchronized (resource2) {\n                    System.out.println(Thread.currentThread() + &quot;get resource2&quot;);\n                }\n            }\n        }, &quot;\u7ebf\u7a0b 1&quot;).start();\n\n        new Thread(() -&gt; {\n            synchronized (resource2) {\n                System.out.println(Thread.currentThread() + &quot;get resource2&quot;);\n                try {\n                    Thread.sleep(1000);\n                } catch (InterruptedException e) {\n                    e.printStackTrace();\n                }\n                System.out.println(Thread.currentThread() + &quot;waiting get resource1&quot;);\n                synchronized (resource1) {\n                    System.out.println(Thread.currentThread() + &quot;get resource1&quot;);\n                }\n            }\n        }, &quot;\u7ebf\u7a0b 2&quot;).start();\n    }\n}\n\nOutput\n\nThread[\u7ebf\u7a0b 1,5,main]get resource1\nThread[\u7ebf\u7a0b 2,5,main]get resource2\nThread[\u7ebf\u7a0b 1,5,main]waiting get resource2\nThread[\u7ebf\u7a0b 2,5,main]waiting get resource1<\/code><\/pre>\n<p>\u7ebf\u7a0b A \u901a\u8fc7 synchronized (resource1) \u83b7\u5f97 resource1 \u7684\u76d1\u89c6\u5668\u9501\uff0c\u7136\u540e\u901a\u8fc7 Thread.sleep(1000); \u8ba9\u7ebf\u7a0b A \u4f11\u7720 1s\uff0c\u4e3a\u7684\u662f\u8ba9\u7ebf\u7a0b B \u5f97\u5230\u6267\u884c\u7136\u540e\u83b7\u53d6\u5230 resource2 \u7684\u76d1\u89c6\u5668\u9501\u3002\u7ebf\u7a0b A \u548c\u7ebf\u7a0b B \u4f11\u7720\u7ed3\u675f\u4e86\u90fd\u5f00\u59cb\u4f01\u56fe\u8bf7\u6c42\u83b7\u53d6\u5bf9\u65b9\u7684\u8d44\u6e90\uff0c\u7136\u540e\u8fd9\u4e24\u4e2a\u7ebf\u7a0b\u5c31\u4f1a\u9677\u5165\u4e92\u76f8\u7b49\u5f85\u7684\u72b6\u6001\uff0c\u8fd9\u4e5f\u5c31\u4ea7\u751f\u4e86\u6b7b\u9501\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%BA%A7%E7%94%9F%E6%AD%BB%E9%94%81%E7%9A%84%E5%9B%9B%E4%B8%AA%E5%BF%85%E8%A6%81%E6%9D%A1%E4%BB%B6%EF%BC%9A\"><\/span>\u4ea7\u751f\u6b7b\u9501\u7684\u56db\u4e2a\u5fc5\u8981\u6761\u4ef6\uff1a<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u4e92\u65a5\u6761\u4ef6<\/strong>\uff1a\u8be5\u8d44\u6e90\u4efb\u610f\u4e00\u4e2a\u65f6\u523b\u53ea\u7531\u4e00\u4e2a\u7ebf\u7a0b\u5360\u7528\u3002<\/p>\n<p><strong>\u8bf7\u6c42\u4e0e\u4fdd\u6301\u6761\u4ef6<\/strong>\uff1a\u4e00\u4e2a\u7ebf\u7a0b\u56e0\u8bf7\u6c42\u8d44\u6e90\u800c\u963b\u585e\u65f6\uff0c\u5bf9\u5df2\u83b7\u5f97\u7684\u8d44\u6e90\u4fdd\u6301\u4e0d\u653e\u3002<\/p>\n<p><strong>\u4e0d\u5265\u593a\u6761\u4ef6<\/strong>\uff1a\u7ebf\u7a0b\u5df2\u83b7\u5f97\u7684\u8d44\u6e90\u5728\u672a\u4f7f\u7528\u5b8c\u4e4b\u524d\u4e0d\u80fd\u88ab\u5176\u4ed6\u7ebf\u7a0b\u5f3a\u884c\u5265\u593a\uff0c\u53ea\u6709\u81ea\u5df1\u4f7f\u7528\u5b8c\u6bd5\u540e\u624d\u91ca\u653e\u8d44\u6e90\u3002<\/p>\n<p><strong>\u5faa\u73af\u7b49\u5f85\u6761\u4ef6<\/strong>\uff1a\u82e5\u5e72\u7ebf\u7a0b\u4e4b\u95f4\u5f62\u6210\u4e00\u79cd\u5934\u5c3e\u76f8\u63a5\u7684\u5faa\u73af\u7b49\u5f85\u8d44\u6e90\u5173\u7cfb\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E6%A3%80%E6%B5%8B%E6%AD%BB%E9%94%81%EF%BC%9F\"><\/span>\u5982\u4f55\u68c0\u6d4b\u6b7b\u9501\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u4f7f\u7528jmap\u3001jstack\u7b49\u547d\u4ee4\u67e5\u770b JVM \u7ebf\u7a0b\u6808\u548c\u5806\u5185\u5b58\u7684\u60c5\u51b5\u3002\u5982\u679c\u6709\u6b7b\u9501\uff0cjstack \u7684\u8f93\u51fa\u4e2d\u901a\u5e38\u4f1a\u6709 Found one Java-level deadlock:\u7684\u5b57\u6837\uff0c\u540e\u9762\u4f1a\u8ddf\u7740\u6b7b\u9501\u76f8\u5173\u7684\u7ebf\u7a0b\u4fe1\u606f\u3002\u53e6\u5916\uff0c\u5b9e\u9645\u9879\u76ee\u4e2d\u8fd8\u53ef\u4ee5\u642d\u914d\u4f7f\u7528top\u3001df\u3001free\u7b49\u547d\u4ee4\u67e5\u770b\u64cd\u4f5c\u7cfb\u7edf\u7684\u57fa\u672c\u60c5\u51b5\uff0c\u51fa\u73b0\u6b7b\u9501\u53ef\u80fd\u4f1a\u5bfc\u81f4 CPU\u3001\u5185\u5b58\u7b49\u8d44\u6e90\u6d88\u8017\u8fc7\u9ad8\u3002\u91c7\u7528 VisualVM\u3001JConsole \u7b49\u5de5\u5177\u8fdb\u884c\u6392\u67e5\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752393761807.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E9%A2%84%E9%98%B2%E5%92%8C%E9%81%BF%E5%85%8D%E7%BA%BF%E7%A8%8B%E6%AD%BB%E9%94%81\"><\/span>\u5982\u4f55\u9884\u9632\u548c\u907f\u514d\u7ebf\u7a0b\u6b7b\u9501?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5982\u4f55\u9884\u9632\u6b7b\u9501\uff1f \u7834\u574f\u6b7b\u9501\u7684\u4ea7\u751f\u7684\u5fc5\u8981\u6761\u4ef6\u5373\u53ef\uff1a<br \/>\n<strong>\u7834\u574f\u8bf7\u6c42\u4e0e\u4fdd\u6301\u6761\u4ef6<\/strong>\uff1a\u4e00\u6b21\u6027\u7533\u8bf7\u6240\u6709\u7684\u8d44\u6e90\u3002<br \/>\n<strong>\u7834\u574f\u4e0d\u5265\u593a\u6761\u4ef6\uff1a<\/strong>\u5360\u7528\u90e8\u5206\u8d44\u6e90\u7684\u7ebf\u7a0b\u8fdb\u4e00\u6b65\u7533\u8bf7\u5176\u4ed6\u8d44\u6e90\u65f6\uff0c\u5982\u679c\u7533\u8bf7\u4e0d\u5230\uff0c\u53ef\u4ee5\u4e3b\u52a8\u91ca\u653e\u5b83\u5360\u6709\u7684\u8d44\u6e90\u3002<br \/>\n<strong>\u7834\u574f\u5faa\u73af\u7b49\u5f85\u6761\u4ef6<\/strong>\uff1a\u9760\u6309\u5e8f\u7533\u8bf7\u8d44\u6e90\u6765\u9884\u9632\u3002\u6309\u67d0\u4e00\u987a\u5e8f\u7533\u8bf7\u8d44\u6e90\uff0c\u91ca\u653e\u8d44\u6e90\u5219\u53cd\u5e8f\u91ca\u653e\u3002\u7834\u574f\u5faa\u73af\u7b49\u5f85\u6761\u4ef6\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E9%81%BF%E5%85%8D%E6%AD%BB%E9%94%81%EF%BC%9F\"><\/span>\u5982\u4f55\u907f\u514d\u6b7b\u9501\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u907f\u514d\u6b7b\u9501\u5c31\u662f\u5728\u8d44\u6e90\u5206\u914d\u65f6\uff0c\u501f\u52a9\u4e8e\u7b97\u6cd5\uff08\u6bd4\u5982\u94f6\u884c\u5bb6\u7b97\u6cd5\uff09\u5bf9\u8d44\u6e90\u5206\u914d\u8fdb\u884c\u8ba1\u7b97\u8bc4\u4f30\uff0c\u4f7f\u5176\u8fdb\u5165\u5b89\u5168\u72b6\u6001\u3002<br \/>\n<img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752393839205.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"volatile_%E5%85%B3%E9%94%AE%E5%AD%97\"><\/span>volatile \u5173\u952e\u5b57<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u5982\u4f55\u4fdd\u8bc1\u53d8\u91cf\u7684\u53ef\u89c1\u6027\uff1f<\/strong><br \/>\n\u5728 Java \u4e2d\uff0cvolatile \u5173\u952e\u5b57\u53ef\u4ee5\u4fdd\u8bc1\u53d8\u91cf\u7684\u53ef\u89c1\u6027\uff0c\u5982\u679c\u6211\u4eec\u5c06\u53d8\u91cf\u58f0\u660e\u4e3a volatile \uff0c\u8fd9\u5c31\u6307\u793a JVM\uff0c\u8fd9\u4e2a\u53d8\u91cf\u662f\u5171\u4eab\u4e14\u4e0d\u7a33\u5b9a\u7684\uff0c\u6bcf\u6b21\u4f7f\u7528\u5b83\u90fd\u5230\u4e3b\u5b58\u4e2d\u8fdb\u884c\u8bfb\u53d6\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752393922530.png\" alt=\"file\" \/><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752393930298.png\" alt=\"file\" \/><\/p>\n<p>volatile \u5173\u952e\u5b57\u5176\u5b9e\u5e76\u975e\u662f Java \u8bed\u8a00\u7279\u6709\u7684\uff0c\u5728 C \u8bed\u8a00\u91cc\u4e5f\u6709\uff0c\u5b83\u6700\u539f\u59cb\u7684\u610f\u4e49\u5c31\u662f\u7981\u7528 CPU \u7f13\u5b58\u3002\u5982\u679c\u6211\u4eec\u5c06\u4e00\u4e2a\u53d8\u91cf\u4f7f\u7528 volatile \u4fee\u9970\uff0c\u8fd9\u5c31\u6307\u793a \u7f16\u8bd1\u5668\uff0c\u8fd9\u4e2a\u53d8\u91cf\u662f\u5171\u4eab\u4e14\u4e0d\u7a33\u5b9a\u7684\uff0c\u6bcf\u6b21\u4f7f\u7528\u5b83\u90fd\u5230\u4e3b\u5b58\u4e2d\u8fdb\u884c\u8bfb\u53d6\u3002<\/p>\n<p>volatile \u5173\u952e\u5b57\u80fd\u4fdd\u8bc1\u6570\u636e\u7684\u53ef\u89c1\u6027\uff0c\u4f46\u4e0d\u80fd\u4fdd\u8bc1\u6570\u636e\u7684\u539f\u5b50\u6027\u3002synchronized \u5173\u952e\u5b57\u4e24\u8005\u90fd\u80fd\u4fdd\u8bc1<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E7%A6%81%E6%AD%A2%E6%8C%87%E4%BB%A4%E9%87%8D%E6%8E%92%E5%BA%8F%EF%BC%9F\"><\/span>\u5982\u4f55\u7981\u6b62\u6307\u4ee4\u91cd\u6392\u5e8f\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u5728 Java \u4e2d\uff0cvolatile \u5173\u952e\u5b57\u9664\u4e86\u53ef\u4ee5\u4fdd\u8bc1\u53d8\u91cf\u7684\u53ef\u89c1\u6027\uff0c\u8fd8\u6709\u4e00\u4e2a\u91cd\u8981\u7684\u4f5c\u7528\u5c31\u662f\u9632\u6b62 JVM \u7684\u6307\u4ee4\u91cd\u6392\u5e8f<\/strong>\u3002 \u5982\u679c\u6211\u4eec\u5c06\u53d8\u91cf\u58f0\u660e\u4e3a volatile \uff0c\u5728\u5bf9\u8fd9\u4e2a\u53d8\u91cf\u8fdb\u884c\u8bfb\u5199\u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u4f1a\u901a\u8fc7\u63d2\u5165\u7279\u5b9a\u7684<strong> \u5185\u5b58\u5c4f\u969c<\/strong> \u7684\u65b9\u5f0f\u6765\u7981\u6b62\u6307\u4ee4\u91cd\u6392\u5e8f\u3002<\/p>\n<p>\u5728 Java \u4e2d\uff0cUnsafe \u7c7b\u63d0\u4f9b\u4e86\u4e09\u4e2a\u5f00\u7bb1\u5373\u7528\u7684\u5185\u5b58\u5c4f\u969c\u76f8\u5173\u7684\u65b9\u6cd5\uff0c\u5c4f\u853d\u4e86\u64cd\u4f5c\u7cfb\u7edf\u5e95\u5c42\u7684\u5dee\u5f02\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public native void loadFence();\npublic native void storeFence();\npublic native void fullFence();<\/code><\/pre>\n<p>\u7406\u8bba\u4e0a\u6765\u8bf4\uff0c\u4f60\u901a\u8fc7\u8fd9\u4e2a\u4e09\u4e2a\u65b9\u6cd5\u4e5f\u53ef\u4ee5\u5b9e\u73b0\u548cvolatile\u7981\u6b62\u91cd\u6392\u5e8f\u4e00\u6837\u7684\u6548\u679c\uff0c\u53ea\u662f\u4f1a\u9ebb\u70e6\u4e00\u4e9b\u3002<\/p>\n<p>\u4e0b\u9762\u6211\u4ee5\u4e00\u4e2a\u5e38\u89c1\u7684\u9762\u8bd5\u9898\u4e3a\u4f8b\u8bb2\u89e3\u4e00\u4e0b volatile \u5173\u952e\u5b57\u7981\u6b62\u6307\u4ee4\u91cd\u6392\u5e8f\u7684\u6548\u679c\u3002<\/p>\n<p>\u9762\u8bd5\u4e2d\u9762\u8bd5\u5b98\u7ecf\u5e38\u4f1a\u8bf4\uff1a\u201c\u5355\u4f8b\u6a21\u5f0f\u4e86\u89e3\u5417\uff1f\u6765\u7ed9\u6211\u624b\u5199\u4e00\u4e0b\uff01\u7ed9\u6211\u89e3\u91ca\u4e00\u4e0b\u53cc\u91cd\u68c0\u9a8c\u9501\u65b9\u5f0f\u5b9e\u73b0\u5355\u4f8b\u6a21\u5f0f\u7684\u539f\u7406\u5457\uff01\u201d<\/p>\n<p><strong>\u53cc\u91cd\u6821\u9a8c\u9501\u5b9e\u73b0\u5bf9\u8c61\u5355\u4f8b\uff08\u7ebf\u7a0b\u5b89\u5168\uff09\uff1a<\/strong><\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class Singleton {\n\n    private volatile static Singleton uniqueInstance;\n\n    private Singleton() {\n    }\n\n    public static Singleton getUniqueInstance() {\n       \/\/\u5148\u5224\u65ad\u5bf9\u8c61\u662f\u5426\u5df2\u7ecf\u5b9e\u4f8b\u8fc7\uff0c\u6ca1\u6709\u5b9e\u4f8b\u5316\u8fc7\u624d\u8fdb\u5165\u52a0\u9501\u4ee3\u7801\n        if (uniqueInstance == null) {\n            \/\/\u7c7b\u5bf9\u8c61\u52a0\u9501\n            synchronized (Singleton.class) {\n                if (uniqueInstance == null) {\n                    uniqueInstance = new Singleton();\n                }\n            }\n        }\n        return uniqueInstance;\n    }\n}<\/code><\/pre>\n<p>uniqueInstance \u91c7\u7528 volatile \u5173\u952e\u5b57\u4fee\u9970\u4e5f\u662f\u5f88\u6709\u5fc5\u8981\u7684\uff0c uniqueInstance = new Singleton(); \u8fd9\u6bb5\u4ee3\u7801\u5176\u5b9e\u662f\u5206\u4e3a\u4e09\u6b65\u6267\u884c\uff1a<\/p>\n<p>1\u3001\u4e3a uniqueInstance \u5206\u914d\u5185\u5b58\u7a7a\u95f4<br \/>\n2\u3001\u521d\u59cb\u5316 uniqueInstance<br \/>\n3\u3001\u5c06 uniqueInstance \u6307\u5411\u5206\u914d\u7684\u5185\u5b58\u5730\u5740<\/p>\n<p>\u4f46\u662f\u7531\u4e8e JVM \u5177\u6709\u6307\u4ee4\u91cd\u6392\u7684\u7279\u6027\uff0c\u6267\u884c\u987a\u5e8f\u6709\u53ef\u80fd\u53d8\u6210 1-&gt;3-&gt;2\u3002\u6307\u4ee4\u91cd\u6392\u5728\u5355\u7ebf\u7a0b\u73af\u5883\u4e0b\u4e0d\u4f1a\u51fa\u73b0\u95ee\u9898\uff0c\u4f46\u662f\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u4f1a\u5bfc\u81f4\u4e00\u4e2a\u7ebf\u7a0b\u83b7\u5f97\u8fd8\u6ca1\u6709\u521d\u59cb\u5316\u7684\u5b9e\u4f8b\u3002\u4f8b\u5982\uff0c\u7ebf\u7a0b T1 \u6267\u884c\u4e86 1 \u548c 3\uff0c\u6b64\u65f6 T2 \u8c03\u7528 getUniqueInstance() \u540e\u53d1\u73b0 uniqueInstance \u4e0d\u4e3a\u7a7a\uff0c\u56e0\u6b64\u8fd4\u56de uniqueInstance\uff0c\u4f46\u6b64\u65f6 uniqueInstance \u8fd8\u672a\u88ab\u521d\u59cb\u5316\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"volatile_%E5%8F%AF%E4%BB%A5%E4%BF%9D%E8%AF%81%E5%8E%9F%E5%AD%90%E6%80%A7%E4%B9%88%EF%BC%9F\"><\/span>volatile \u53ef\u4ee5\u4fdd\u8bc1\u539f\u5b50\u6027\u4e48\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>volatile \u5173\u952e\u5b57\u80fd\u4fdd\u8bc1\u53d8\u91cf\u7684\u53ef\u89c1\u6027\uff0c\u4f46\u4e0d\u80fd\u4fdd\u8bc1\u5bf9\u53d8\u91cf\u7684\u64cd\u4f5c\u662f\u539f\u5b50\u6027\u7684\u3002<\/strong><\/p>\n<p>\u6211\u4eec\u901a\u8fc7\u4e0b\u9762\u7684\u4ee3\u7801\u5373\u53ef\u8bc1\u660e\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">\npublic class VolatileAtomicityDemo {\n    public volatile static int inc = 0;\n\n    public void increase() {\n        inc++;\n    }\n\n    public static void main(String[] args) throws InterruptedException {\n        ExecutorService threadPool = Executors.newFixedThreadPool(5);\n        VolatileAtomicityDemo volatileAtomicityDemo = new VolatileAtomicityDemo();\n        for (int i = 0; i &lt; 5; i++) {\n            threadPool.execute(() -&gt; {\n                for (int j = 0; j &lt; 500; j++) {\n                    volatileAtomicityDemo.increase();\n                }\n            });\n        }\n        \/\/ \u7b49\u5f851.5\u79d2\uff0c\u4fdd\u8bc1\u4e0a\u9762\u7a0b\u5e8f\u6267\u884c\u5b8c\u6210\n        Thread.sleep(1500);\n        System.out.println(inc);\n        threadPool.shutdown();\n    }\n}<\/code><\/pre>\n<p>\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u8fd0\u884c\u4e0a\u9762\u7684\u4ee3\u7801\u7406\u5e94\u8f93\u51fa 2500\u3002\u4f46\u4f60\u771f\u6b63\u8fd0\u884c\u4e86\u4e0a\u9762\u7684\u4ee3\u7801\u4e4b\u540e\uff0c\u4f60\u4f1a\u53d1\u73b0\u6bcf\u6b21\u8f93\u51fa\u7ed3\u679c\u90fd\u5c0f\u4e8e 2500\u3002<\/p>\n<p>\u4e3a\u4ec0\u4e48\u4f1a\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u5462\uff1f\u4e0d\u662f\u8bf4\u597d\u4e86\uff0cvolatile \u53ef\u4ee5\u4fdd\u8bc1\u53d8\u91cf\u7684\u53ef\u89c1\u6027\u561b\uff01<\/p>\n<p>\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c volatile \u80fd\u4fdd\u8bc1 inc++ \u64cd\u4f5c\u7684\u539f\u5b50\u6027\u7684\u8bdd\u3002\u6bcf\u4e2a\u7ebf\u7a0b\u4e2d\u5bf9 inc \u53d8\u91cf\u81ea\u589e\u5b8c\u4e4b\u540e\uff0c\u5176\u4ed6\u7ebf\u7a0b\u53ef\u4ee5\u7acb\u5373\u770b\u5230\u4fee\u6539\u540e\u7684\u503c\u30025 \u4e2a\u7ebf\u7a0b\u5206\u522b\u8fdb\u884c\u4e86 500 \u6b21\u64cd\u4f5c\uff0c\u90a3\u4e48\u6700\u7ec8 inc \u7684\u503c\u5e94\u8be5\u662f 5*500=2500\u3002<\/p>\n<p>\u5f88\u591a\u4eba\u4f1a\u8bef\u8ba4\u4e3a\u81ea\u589e\u64cd\u4f5c inc++ \u662f\u539f\u5b50\u6027\u7684\uff0c\u5b9e\u9645\u4e0a\uff0cinc++ \u5176\u5b9e\u662f\u4e00\u4e2a\u590d\u5408\u64cd\u4f5c\uff0c\u5305\u62ec\u4e09\u6b65\uff1a<\/p>\n<p>1\u3001\u8bfb\u53d6 inc \u7684\u503c\u3002<br \/>\n2\u3001\u5bf9 inc \u52a0 1\u3002<br \/>\n3\u3001\u5c06 inc \u7684\u503c\u5199\u56de\u5185\u5b58\u3002<\/p>\n<p>volatile \u662f\u65e0\u6cd5\u4fdd\u8bc1\u8fd9\u4e09\u4e2a\u64cd\u4f5c\u662f\u5177\u6709\u539f\u5b50\u6027\u7684\uff0c\u6709\u53ef\u80fd\u5bfc\u81f4\u4e0b\u9762\u8fd9\u79cd\u60c5\u51b5\u51fa\u73b0\uff1a<\/p>\n<p>1\u3001\u7ebf\u7a0b 1 \u5bf9 inc \u8fdb\u884c\u8bfb\u53d6\u64cd\u4f5c\u4e4b\u540e\uff0c\u8fd8\u672a\u5bf9\u5176\u8fdb\u884c\u4fee\u6539\u3002\u7ebf\u7a0b 2 \u53c8\u8bfb\u53d6\u4e86 inc\u7684\u503c\u5e76\u5bf9\u5176\u8fdb\u884c\u4fee\u6539\uff08+1\uff09\uff0c\u518d\u5c06inc \u7684\u503c\u5199\u56de\u5185\u5b58\u3002<br \/>\n2\u3001\u7ebf\u7a0b 2 \u64cd\u4f5c\u5b8c\u6bd5\u540e\uff0c\u7ebf\u7a0b 1 \u5bf9 inc\u7684\u503c\u8fdb\u884c\u4fee\u6539\uff08+1\uff09\uff0c\u518d\u5c06inc \u7684\u503c\u5199\u56de\u5185\u5b58\u3002<\/p>\n<p>\u8fd9\u4e5f\u5c31\u5bfc\u81f4\u4e24\u4e2a\u7ebf\u7a0b\u5206\u522b\u5bf9 inc \u8fdb\u884c\u4e86\u4e00\u6b21\u81ea\u589e\u64cd\u4f5c\u540e\uff0cinc \u5b9e\u9645\u4e0a\u53ea\u589e\u52a0\u4e86 1\u3002<br \/>\n\u5176\u5b9e\uff0c\u5982\u679c\u60f3\u8981\u4fdd\u8bc1\u4e0a\u9762\u7684\u4ee3\u7801\u8fd0\u884c\u6b63\u786e\u4e5f\u975e\u5e38\u7b80\u5355\uff0c\u5229\u7528 synchronized\u3001Lock\u6216\u8005AtomicInteger\u90fd\u53ef\u4ee5\u3002<\/p>\n<p>\u4f7f\u7528 synchronized \u6539\u8fdb\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public synchronized void increase() {\n    inc++;\n}<\/code><\/pre>\n<p>\u4f7f\u7528 AtomicInteger \u6539\u8fdb\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public AtomicInteger inc = new AtomicInteger();\n\npublic void increase() {\n    inc.getAndIncrement();\n}<\/code><\/pre>\n<p>\u4f7f\u7528 ReentrantLock \u6539\u8fdb\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">Lock lock = new ReentrantLock();\npublic void increase() {\n    lock.lock();\n    try {\n        inc++;\n    } finally {\n        lock.unlock();\n    }\n}<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B9%90%E8%A7%82%E9%94%81%E5%92%8C%E6%82%B2%E8%A7%82%E9%94%81\"><\/span>\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"%E4%BB%80%E4%B9%88%E6%98%AF%E6%82%B2%E8%A7%82%E9%94%81%EF%BC%9F\"><\/span>\u4ec0\u4e48\u662f\u60b2\u89c2\u9501\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u60b2\u89c2\u9501\u603b\u662f\u5047\u8bbe\u6700\u574f\u7684\u60c5\u51b5\uff0c\u8ba4\u4e3a\u5171\u4eab\u8d44\u6e90\u6bcf\u6b21\u88ab\u8bbf\u95ee\u7684\u65f6\u5019\u5c31\u4f1a\u51fa\u73b0\u95ee\u9898(\u6bd4\u5982\u5171\u4eab\u6570\u636e\u88ab\u4fee\u6539)\uff0c\u6240\u4ee5\u6bcf\u6b21\u5728\u83b7\u53d6\u8d44\u6e90\u64cd\u4f5c\u7684\u65f6\u5019\u90fd\u4f1a\u4e0a\u9501\uff0c\u8fd9\u6837\u5176\u4ed6\u7ebf\u7a0b\u60f3\u62ff\u5230\u8fd9\u4e2a\u8d44\u6e90\u5c31\u4f1a\u963b\u585e\u76f4\u5230\u9501\u88ab\u4e0a\u4e00\u4e2a\u6301\u6709\u8005\u91ca\u653e\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c<strong>\u5171\u4eab\u8d44\u6e90\u6bcf\u6b21\u53ea\u7ed9\u4e00\u4e2a\u7ebf\u7a0b\u4f7f\u7528\uff0c\u5176\u5b83\u7ebf\u7a0b\u963b\u585e\uff0c\u7528\u5b8c\u540e\u518d\u628a\u8d44\u6e90\u8f6c\u8ba9\u7ed9\u5176\u5b83\u7ebf\u7a0b\u3002<\/strong><\/p>\n<p>\u50cf Java \u4e2dsynchronized\u548cReentrantLock\u7b49\u72ec\u5360\u9501\u5c31\u662f\u60b2\u89c2\u9501\u601d\u60f3\u7684\u5b9e\u73b0\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public void performSynchronisedTask() {\n    synchronized (this) {\n        \/\/ \u9700\u8981\u540c\u6b65\u7684\u64cd\u4f5c\n    }\n}\n\nprivate Lock lock = new ReentrantLock();\nlock.lock();\ntry {\n   \/\/ \u9700\u8981\u540c\u6b65\u7684\u64cd\u4f5c\n} finally {\n    lock.unlock();\n}<\/code><\/pre>\n<p>\u9ad8\u5e76\u53d1\u7684\u573a\u666f\u4e0b\uff0c\u6fc0\u70c8\u7684\u9501\u7ade\u4e89\u4f1a\u9020\u6210\u7ebf\u7a0b\u963b\u585e\uff0c\u5927\u91cf\u963b\u585e\u7ebf\u7a0b\u4f1a\u5bfc\u81f4\u7cfb\u7edf\u7684\u4e0a\u4e0b\u6587\u5207\u6362\uff0c\u589e\u52a0\u7cfb\u7edf\u7684\u6027\u80fd\u5f00\u9500\u3002\u5e76\u4e14\uff0c\u60b2\u89c2\u9501\u8fd8\u53ef\u80fd\u4f1a\u5b58\u5728\u6b7b\u9501\u95ee\u9898\uff0c\u5f71\u54cd\u4ee3\u7801\u7684\u6b63\u5e38\u8fd0\u884c<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%BB%80%E4%B9%88%E6%98%AF%E4%B9%90%E8%A7%82%E9%94%81%EF%BC%9F\"><\/span>\u4ec0\u4e48\u662f\u4e50\u89c2\u9501\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u4e50\u89c2\u9501\u603b\u662f\u5047\u8bbe\u6700\u597d\u7684\u60c5\u51b5\uff0c\u8ba4\u4e3a\u5171\u4eab\u8d44\u6e90\u6bcf\u6b21\u88ab\u8bbf\u95ee\u7684\u65f6\u5019\u4e0d\u4f1a\u51fa\u73b0\u95ee\u9898\uff0c\u7ebf\u7a0b\u53ef\u4ee5\u4e0d\u505c\u5730\u6267\u884c\uff0c\u65e0\u9700\u52a0\u9501\u4e5f\u65e0\u9700\u7b49\u5f85\uff0c\u53ea\u662f\u5728\u63d0\u4ea4\u4fee\u6539\u7684\u65f6\u5019\u53bb\u9a8c\u8bc1\u5bf9\u5e94\u7684\u8d44\u6e90\uff08\u4e5f\u5c31\u662f\u6570\u636e\uff09\u662f\u5426\u88ab\u5176\u5b83\u7ebf\u7a0b\u4fee\u6539\u4e86\uff08\u5177\u4f53\u65b9\u6cd5\u53ef\u4ee5\u4f7f\u7528\u7248\u672c\u53f7\u673a\u5236\u6216 CAS \u7b97\u6cd5\uff09\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752394306999.png\" alt=\"file\" \/><\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">\/\/ LongAdder \u5728\u9ad8\u5e76\u53d1\u573a\u666f\u4e0b\u4f1a\u6bd4 AtomicInteger \u548c AtomicLong \u7684\u6027\u80fd\u66f4\u597d\n\/\/ \u4ee3\u4ef7\u5c31\u662f\u4f1a\u6d88\u8017\u66f4\u591a\u7684\u5185\u5b58\u7a7a\u95f4\uff08\u7a7a\u95f4\u6362\u65f6\u95f4\uff09\nLongAdder sum = new LongAdder();\nsum.increment();<\/code><\/pre>\n<p>\u9ad8\u5e76\u53d1\u7684\u573a\u666f\u4e0b\uff0c\u4e50\u89c2\u9501\u76f8\u6bd4\u60b2\u89c2\u9501\u6765\u8bf4\uff0c\u4e0d\u5b58\u5728\u9501\u7ade\u4e89\u9020\u6210\u7ebf\u7a0b\u963b\u585e\uff0c\u4e5f\u4e0d\u4f1a\u6709\u6b7b\u9501\u7684\u95ee\u9898\uff0c\u5728\u6027\u80fd\u4e0a\u5f80\u5f80\u4f1a\u66f4\u80dc\u4e00\u7b79\u3002\u4f46\u662f\uff0c\u5982\u679c\u51b2\u7a81\u9891\u7e41\u53d1\u751f\uff08\u5199\u5360\u6bd4\u975e\u5e38\u591a\u7684\u60c5\u51b5\uff09\uff0c\u4f1a\u9891\u7e41\u5931\u8d25\u548c\u91cd\u8bd5\uff0c\u8fd9\u6837\u540c\u6837\u4f1a\u975e\u5e38\u5f71\u54cd\u6027\u80fd\uff0c\u5bfc\u81f4 CPU \u98d9\u5347\u3002<\/p>\n<p>\u4e0d\u8fc7\uff0c\u5927\u91cf\u5931\u8d25\u91cd\u8bd5\u7684\u95ee\u9898\u4e5f\u662f\u53ef\u4ee5\u89e3\u51b3\u7684\uff0c\u50cf\u6211\u4eec\u524d\u9762\u63d0\u5230\u7684 LongAdder\u4ee5\u7a7a\u95f4\u6362\u65f6\u95f4\u7684\u65b9\u5f0f\u5c31\u89e3\u51b3\u4e86\u8fd9\u4e2a\u95ee\u9898\u3002<\/p>\n<p><strong>\u7406\u8bba\u4e0a\u6765\u8bf4\uff1a<\/strong><br \/>\n\u60b2\u89c2\u9501\u901a\u5e38\u591a\u7528\u4e8e\u5199\u6bd4\u8f83\u591a\u7684\u60c5\u51b5\uff08\u591a\u5199\u573a\u666f\uff0c\u7ade\u4e89\u6fc0\u70c8\uff09\uff0c\u8fd9\u6837\u53ef\u4ee5\u907f\u514d\u9891\u7e41\u5931\u8d25\u548c\u91cd\u8bd5\u5f71\u54cd\u6027\u80fd\uff0c\u60b2\u89c2\u9501\u7684\u5f00\u9500\u662f\u56fa\u5b9a\u7684\u3002\u4e0d\u8fc7\uff0c\u5982\u679c\u4e50\u89c2\u9501\u89e3\u51b3\u4e86\u9891\u7e41\u5931\u8d25\u548c\u91cd\u8bd5\u8fd9\u4e2a\u95ee\u9898\u7684\u8bdd\uff08\u6bd4\u5982LongAdder\uff09\uff0c\u4e5f\u662f\u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u4e50\u89c2\u9501\u7684\uff0c\u8981\u89c6\u5b9e\u9645\u60c5\u51b5\u800c\u5b9a\u3002<\/p>\n<p>\u4e50\u89c2\u9501\u901a\u5e38\u591a\u7528\u4e8e\u5199\u6bd4\u8f83\u5c11\u7684\u60c5\u51b5\uff08\u591a\u8bfb\u573a\u666f\uff0c\u7ade\u4e89\u8f83\u5c11\uff09\uff0c\u8fd9\u6837\u53ef\u4ee5\u907f\u514d\u9891\u7e41\u52a0\u9501\u5f71\u54cd\u6027\u80fd\u3002\u4e0d\u8fc7\uff0c\u4e50\u89c2\u9501\u4e3b\u8981\u9488\u5bf9\u7684\u5bf9\u8c61\u662f\u5355\u4e2a\u5171\u4eab\u53d8\u91cf\uff08\u53c2\u8003java.util.concurrent.atomic\u5305\u4e0b\u9762\u7684\u539f\u5b50\u53d8\u91cf\u7c7b\uff09\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E5%AE%9E%E7%8E%B0%E4%B9%90%E8%A7%82%E9%94%81%EF%BC%9F\"><\/span>\u5982\u4f55\u5b9e\u73b0\u4e50\u89c2\u9501\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u4e50\u89c2\u9501\u4e00\u822c\u4f1a\u4f7f\u7528\u7248\u672c\u53f7\u673a\u5236\u6216 CAS \u7b97\u6cd5\u5b9e\u73b0\uff0cCAS \u7b97\u6cd5\u76f8\u5bf9\u6765\u8bf4\u66f4\u591a\u4e00\u4e9b\uff0c\u8fd9\u91cc\u9700\u8981\u683c\u5916\u6ce8\u610f\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E7%89%88%E6%9C%AC%E5%8F%B7%E6%9C%BA%E5%88%B6\"><\/span>\u7248\u672c\u53f7\u673a\u5236<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u4e00\u822c\u662f\u5728\u6570\u636e\u8868\u4e2d\u52a0\u4e0a\u4e00\u4e2a\u6570\u636e\u7248\u672c\u53f7 version \u5b57\u6bb5\uff0c\u8868\u793a\u6570\u636e\u88ab\u4fee\u6539\u7684\u6b21\u6570\u3002\u5f53\u6570\u636e\u88ab\u4fee\u6539\u65f6\uff0cversion \u503c\u4f1a\u52a0\u4e00\u3002\u5f53\u7ebf\u7a0b A \u8981\u66f4\u65b0\u6570\u636e\u503c\u65f6\uff0c\u5728\u8bfb\u53d6\u6570\u636e\u7684\u540c\u65f6\u4e5f\u4f1a\u8bfb\u53d6 version \u503c\uff0c\u5728\u63d0\u4ea4\u66f4\u65b0\u65f6\uff0c\u82e5\u521a\u624d\u8bfb\u53d6\u5230\u7684 version \u503c\u4e3a\u5f53\u524d\u6570\u636e\u5e93\u4e2d\u7684 version \u503c\u76f8\u7b49\u65f6\u624d\u66f4\u65b0\uff0c\u5426\u5219\u91cd\u8bd5\u66f4\u65b0\u64cd\u4f5c\uff0c\u76f4\u5230\u66f4\u65b0\u6210\u529f\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"CAS_%E7%AE%97%E6%B3%95\"><\/span>CAS \u7b97\u6cd5<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>CAS \u7684\u5168\u79f0\u662f <strong>Compare And Swap\uff08\u6bd4\u8f83\u4e0e\u4ea4\u6362\uff09<\/strong> \uff0c\u7528\u4e8e\u5b9e\u73b0\u4e50\u89c2\u9501\uff0c\u88ab\u5e7f\u6cdb\u5e94\u7528\u4e8e\u5404\u5927\u6846\u67b6\u4e2d\u3002CAS \u7684\u601d\u60f3\u5f88\u7b80\u5355\uff0c\u5c31\u662f\u7528\u4e00\u4e2a\u9884\u671f\u503c\u548c\u8981\u66f4\u65b0\u7684\u53d8\u91cf\u503c\u8fdb\u884c\u6bd4\u8f83\uff0c\u4e24\u503c\u76f8\u7b49\u624d\u4f1a\u8fdb\u884c\u66f4\u65b0\u3002<\/p>\n<p>CAS \u662f\u4e00\u4e2a\u539f\u5b50\u64cd\u4f5c\uff0c\u5e95\u5c42\u4f9d\u8d56\u4e8e\u4e00\u6761 CPU \u7684\u539f\u5b50\u6307\u4ee4\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752394442251.png\" alt=\"file\" \/><\/p>\n<p><strong>CAS \u6d89\u53ca\u5230\u4e09\u4e2a\u64cd\u4f5c\u6570<\/strong>\uff1a<\/p>\n<p><strong>V\uff1a<\/strong>\u8981\u66f4\u65b0\u7684\u53d8\u91cf\u503c(Var)<br \/>\n<strong>E\uff1a<\/strong>\u9884\u671f\u503c(Expected)<br \/>\n<strong>N\uff1a<\/strong>\u62df\u5199\u5165\u7684\u65b0\u503c(New)<\/p>\n<p>\u5f53\u4e14\u4ec5\u5f53 V \u7684\u503c\u7b49\u4e8e E \u65f6\uff0cCAS \u901a\u8fc7\u539f\u5b50\u65b9\u5f0f\u7528\u65b0\u503c N \u6765\u66f4\u65b0 V \u7684\u503c\u3002\u5982\u679c\u4e0d\u7b49\uff0c\u8bf4\u660e\u5df2\u7ecf\u6709\u5176\u5b83\u7ebf\u7a0b\u66f4\u65b0\u4e86 V\uff0c\u5219\u5f53\u524d\u7ebf\u7a0b\u653e\u5f03\u66f4\u65b0\u3002<\/p>\n<p>\u4e3e\u4e00\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\uff1a\u7ebf\u7a0b A \u8981\u4fee\u6539\u53d8\u91cf i \u7684\u503c\u4e3a 6\uff0ci \u539f\u503c\u4e3a 1\uff08V = 1\uff0cE=1\uff0cN=6\uff0c\u5047\u8bbe\u4e0d\u5b58\u5728 ABA \u95ee\u9898\uff09\u3002<br \/>\n1\u3001i \u4e0e 1 \u8fdb\u884c\u6bd4\u8f83\uff0c\u5982\u679c\u76f8\u7b49\uff0c \u5219\u8bf4\u660e\u6ca1\u88ab\u5176\u4ed6\u7ebf\u7a0b\u4fee\u6539\uff0c\u53ef\u4ee5\u88ab\u8bbe\u7f6e\u4e3a 6 \u3002<br \/>\n2\u3001i \u4e0e 1 \u8fdb\u884c\u6bd4\u8f83\uff0c\u5982\u679c\u4e0d\u76f8\u7b49\uff0c\u5219\u8bf4\u660e\u88ab\u5176\u4ed6\u7ebf\u7a0b\u4fee\u6539\uff0c\u5f53\u524d\u7ebf\u7a0b\u653e\u5f03\u66f4\u65b0\uff0cCAS \u64cd\u4f5c\u5931\u8d25\u3002<\/p>\n<p>\u5f53\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u4f7f\u7528 CAS \u64cd\u4f5c\u4e00\u4e2a\u53d8\u91cf\u65f6\uff0c\u53ea\u6709\u4e00\u4e2a\u4f1a\u80dc\u51fa\uff0c\u5e76\u6210\u529f\u66f4\u65b0\uff0c\u5176\u4f59\u5747\u4f1a\u5931\u8d25\uff0c\u4f46\u5931\u8d25\u7684\u7ebf\u7a0b\u5e76\u4e0d\u4f1a\u88ab\u6302\u8d77\uff0c\u4ec5\u662f\u88ab\u544a\u77e5\u5931\u8d25\uff0c\u5e76\u4e14\u5141\u8bb8\u518d\u6b21\u5c1d\u8bd5\uff0c\u5f53\u7136\u4e5f\u5141\u8bb8\u5931\u8d25\u7684\u7ebf\u7a0b\u653e\u5f03\u64cd\u4f5c\u3002<\/p>\n<p>Java \u8bed\u8a00\u5e76\u6ca1\u6709\u76f4\u63a5\u5b9e\u73b0 CAS\uff0cCAS \u76f8\u5173\u7684\u5b9e\u73b0\u662f\u901a\u8fc7 C++ \u5185\u8054\u6c47\u7f16\u7684\u5f62\u5f0f\u5b9e\u73b0\u7684\uff08JNI \u8c03\u7528\uff09\u3002\u56e0\u6b64\uff0c CAS \u7684\u5177\u4f53\u5b9e\u73b0\u548c\u64cd\u4f5c\u7cfb\u7edf\u4ee5\u53ca CPU \u90fd\u6709\u5173\u7cfb\u3002<\/p>\n<p>sun.misc\u5305\u4e0b\u7684Unsafe\u7c7b\u63d0\u4f9b\u4e86compareAndSwapObject\u3001compareAndSwapInt\u3001compareAndSwapLong\u65b9\u6cd5\u6765\u5b9e\u73b0\u7684\u5bf9Object\u3001int\u3001long\u7c7b\u578b\u7684 CAS \u64cd\u4f5c<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">\/**\n  *  CAS\n  * @param o         \u5305\u542b\u8981\u4fee\u6539field\u7684\u5bf9\u8c61\n  * @param offset    \u5bf9\u8c61\u4e2d\u67d0field\u7684\u504f\u79fb\u91cf\n  * @param expected  \u671f\u671b\u503c\n  * @param update    \u66f4\u65b0\u503c\n  * @return          true | false\n  *\/\npublic final native boolean compareAndSwapObject(Object o, long offset,  Object expected, Object update);\n\npublic final native boolean compareAndSwapInt(Object o, long offset, int expected,int update);\n\npublic final native boolean compareAndSwapLong(Object o, long offset, long expected, long update);<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"Java_%E4%B8%AD_CAS_%E6%98%AF%E5%A6%82%E4%BD%95%E5%AE%9E%E7%8E%B0%E7%9A%84%EF%BC%9F\"><\/span>Java \u4e2d CAS \u662f\u5982\u4f55\u5b9e\u73b0\u7684\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5728 Java \u4e2d\uff0c\u5b9e\u73b0 CAS\uff08Compare-And-Swap, \u6bd4\u8f83\u5e76\u4ea4\u6362\uff09\u64cd\u4f5c\u7684\u4e00\u4e2a\u5173\u952e\u7c7b\u662f<strong>Unsafe<\/strong>\u3002<\/p>\n<p>Unsafe\u7c7b\u4f4d\u4e8esun.misc\u5305\u4e0b\uff0c\u662f\u4e00\u4e2a\u63d0\u4f9b\u4f4e\u7ea7\u522b\u3001\u4e0d\u5b89\u5168\u64cd\u4f5c\u7684\u7c7b\u3002\u7531\u4e8e\u5176\u5f3a\u5927\u7684\u529f\u80fd\u548c\u6f5c\u5728\u7684\u5371\u9669\u6027\uff0c\u5b83\u901a\u5e38\u7528\u4e8e JVM \u5185\u90e8\u6216\u4e00\u4e9b\u9700\u8981\u6781\u9ad8\u6027\u80fd\u548c\u5e95\u5c42\u8bbf\u95ee\u7684\u5e93\u4e2d\uff0c\u800c\u4e0d\u63a8\u8350\u666e\u901a\u5f00\u53d1\u8005\u5728\u5e94\u7528\u7a0b\u5e8f\u4e2d\u4f7f\u7528<\/p>\n<p>sun.misc\u5305\u4e0b\u7684Unsafe\u7c7b\u63d0\u4f9b\u4e86compareAndSwapObject\u3001compareAndSwapInt\u3001compareAndSwapLong\u65b9\u6cd5\u6765\u5b9e\u73b0\u7684\u5bf9Object\u3001int\u3001long\u7c7b\u578b\u7684 CAS \u64cd\u4f5c\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">\/**\n * \u4ee5\u539f\u5b50\u65b9\u5f0f\u66f4\u65b0\u5bf9\u8c61\u5b57\u6bb5\u7684\u503c\u3002\n *\n * @param o        \u8981\u64cd\u4f5c\u7684\u5bf9\u8c61\n * @param offset   \u5bf9\u8c61\u5b57\u6bb5\u7684\u5185\u5b58\u504f\u79fb\u91cf\n * @param expected \u671f\u671b\u7684\u65e7\u503c\n * @param x        \u8981\u8bbe\u7f6e\u7684\u65b0\u503c\n * @return \u5982\u679c\u503c\u88ab\u6210\u529f\u66f4\u65b0\uff0c\u5219\u8fd4\u56de true\uff1b\u5426\u5219\u8fd4\u56de false\n *\/\nboolean compareAndSwapObject(Object o, long offset, Object expected, Object x);\n\n\/**\n * \u4ee5\u539f\u5b50\u65b9\u5f0f\u66f4\u65b0 int \u7c7b\u578b\u7684\u5bf9\u8c61\u5b57\u6bb5\u7684\u503c\u3002\n *\/\nboolean compareAndSwapInt(Object o, long offset, int expected, int x);\n\n\/**\n * \u4ee5\u539f\u5b50\u65b9\u5f0f\u66f4\u65b0 long \u7c7b\u578b\u7684\u5bf9\u8c61\u5b57\u6bb5\u7684\u503c\u3002\n *\/\nboolean compareAndSwapLong(Object o, long offset, long expected, long x);<\/code><\/pre>\n<p>Unsafe\u7c7b\u4e2d\u7684 CAS \u65b9\u6cd5\u662fnative\u65b9\u6cd5\u3002native\u5173\u952e\u5b57\u8868\u660e\u8fd9\u4e9b\u65b9\u6cd5\u662f\u7528\u672c\u5730\u4ee3\u7801\uff08\u901a\u5e38\u662f C \u6216 C++\uff09\u5b9e\u73b0\u7684\uff0c\u800c\u4e0d\u662f\u7528 Java \u5b9e\u73b0\u7684\u3002\u8fd9\u4e9b\u65b9\u6cd5\u76f4\u63a5\u8c03\u7528\u5e95\u5c42\u7684\u786c\u4ef6\u6307\u4ee4\u6765\u5b9e\u73b0\u539f\u5b50\u64cd\u4f5c\u3002\u4e5f\u5c31\u662f\u8bf4\uff0cJava \u8bed\u8a00\u5e76\u6ca1\u6709\u76f4\u63a5\u7528 Java \u5b9e\u73b0 CAS\uff0c\u800c\u662f\u901a\u8fc7 C++ \u5185\u8054\u6c47\u7f16\u7684\u5f62\u5f0f\u5b9e\u73b0\u7684\uff08\u901a\u8fc7 JNI \u8c03\u7528\uff09\u3002\u56e0\u6b64\uff0cCAS \u7684\u5177\u4f53\u5b9e\u73b0\u4e0e\u64cd\u4f5c\u7cfb\u7edf\u4ee5\u53ca CPU \u5bc6\u5207\u76f8\u5173\u3002<br \/>\n<img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752394724284.png\" alt=\"file\" \/><\/p>\n<p>AtomicInteger\u662f Java \u7684\u539f\u5b50\u7c7b\u4e4b\u4e00\uff0c\u4e3b\u8981\u7528\u4e8e\u5bf9 int \u7c7b\u578b\u7684\u53d8\u91cf\u8fdb\u884c\u539f\u5b50\u64cd\u4f5c\uff0c\u5b83\u5229\u7528Unsafe\u7c7b\u63d0\u4f9b\u7684\u4f4e\u7ea7\u522b\u539f\u5b50\u64cd\u4f5c\u65b9\u6cd5\u5b9e\u73b0\u65e0\u9501\u7684\u7ebf\u7a0b\u5b89\u5168\u6027\u3002\u4e0b\u9762\uff0c\u6211\u4eec\u901a\u8fc7\u89e3\u8bfbAtomicInteger\u7684\u6838\u5fc3\u6e90\u7801\uff08JDK1.8\uff09\uff0c\u6765\u8bf4\u660e Java \u5982\u4f55\u4f7f\u7528Unsafe\u7c7b\u7684\u65b9\u6cd5\u6765\u5b9e\u73b0\u539f\u5b50\u64cd\u4f5c\u3002AtomicInteger\u6838\u5fc3\u6e90\u7801\u5982\u4e0b\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">\/\/ \u83b7\u53d6 Unsafe \u5b9e\u4f8b\nprivate static final Unsafe unsafe = Unsafe.getUnsafe();\nprivate static final long valueOffset;\n\nstatic {\n    try {\n        \/\/ \u83b7\u53d6\u201cvalue\u201d\u5b57\u6bb5\u5728AtomicInteger\u7c7b\u4e2d\u7684\u5185\u5b58\u504f\u79fb\u91cf\n        valueOffset = unsafe.objectFieldOffset\n            (AtomicInteger.class.getDeclaredField(&quot;value&quot;));\n    } catch (Exception ex) { throw new Error(ex); }\n}\n\/\/ \u786e\u4fdd\u201cvalue\u201d\u5b57\u6bb5\u7684\u53ef\u89c1\u6027\nprivate volatile int value;\n\n\/\/ \u5982\u679c\u5f53\u524d\u503c\u7b49\u4e8e\u9884\u671f\u503c\uff0c\u5219\u539f\u5b50\u5730\u5c06\u503c\u8bbe\u7f6e\u4e3anewValue\n\/\/ \u4f7f\u7528 Unsafe#compareAndSwapInt \u65b9\u6cd5\u8fdb\u884cCAS\u64cd\u4f5c\npublic final boolean compareAndSet(int expect, int update) {\n    return unsafe.compareAndSwapInt(this, valueOffset, expect, update);\n}\n\n\/\/ \u539f\u5b50\u5730\u5c06\u5f53\u524d\u503c\u52a0 delta \u5e76\u8fd4\u56de\u65e7\u503c\npublic final int getAndAdd(int delta) {\n    return unsafe.getAndAddInt(this, valueOffset, delta);\n}\n\n\/\/ \u539f\u5b50\u5730\u5c06\u5f53\u524d\u503c\u52a0 1 \u5e76\u8fd4\u56de\u52a0\u4e4b\u524d\u7684\u503c\uff08\u65e7\u503c\uff09\n\/\/ \u4f7f\u7528 Unsafe#getAndAddInt \u65b9\u6cd5\u8fdb\u884cCAS\u64cd\u4f5c\u3002\npublic final int getAndIncrement() {\n    return unsafe.getAndAddInt(this, valueOffset, 1);\n}\n\n\/\/ \u539f\u5b50\u5730\u5c06\u5f53\u524d\u503c\u51cf 1 \u5e76\u8fd4\u56de\u51cf\u4e4b\u524d\u7684\u503c\uff08\u65e7\u503c\uff09\npublic final int getAndDecrement() {\n    return unsafe.getAndAddInt(this, valueOffset, -1);\n}\n\nUnsafe#getAndAddInt\u6e90\u7801\uff1a\n\/\/ \u539f\u5b50\u5730\u83b7\u53d6\u5e76\u589e\u52a0\u6574\u6570\u503c\npublic final int getAndAddInt(Object o, long offset, int delta) {\n    int v;\n    do {\n        \/\/ \u4ee5 volatile \u65b9\u5f0f\u83b7\u53d6\u5bf9\u8c61 o \u5728\u5185\u5b58\u504f\u79fb\u91cf offset \u5904\u7684\u6574\u6570\u503c\n        v = getIntVolatile(o, offset);\n    } while (!compareAndSwapInt(o, offset, v, v + delta));\n    \/\/ \u8fd4\u56de\u65e7\u503c\n    return v;\n}\n<\/code><\/pre>\n<p>\u53ef\u4ee5\u770b\u5230\uff0cgetAndAddInt \u4f7f\u7528\u4e86 do-while \u5faa\u73af\uff1a\u5728compareAndSwapInt\u64cd\u4f5c\u5931\u8d25\u65f6\uff0c\u4f1a\u4e0d\u65ad\u91cd\u8bd5\u76f4\u5230\u6210\u529f\u3002\u4e5f\u5c31\u662f\u8bf4\uff0cgetAndAddInt\u65b9\u6cd5\u4f1a\u901a\u8fc7 compareAndSwapInt \u65b9\u6cd5\u6765\u5c1d\u8bd5\u66f4\u65b0 value \u7684\u503c\uff0c\u5982\u679c\u66f4\u65b0\u5931\u8d25\uff08\u5f53\u524d\u503c\u5728\u6b64\u671f\u95f4\u88ab\u5176\u4ed6\u7ebf\u7a0b\u4fee\u6539\uff09\uff0c\u5b83\u4f1a\u91cd\u65b0\u83b7\u53d6\u5f53\u524d\u503c\u5e76\u518d\u6b21\u5c1d\u8bd5\u66f4\u65b0\uff0c\u76f4\u5230\u64cd\u4f5c\u6210\u529f\u3002<\/p>\n<p>\u7531\u4e8e CAS \u64cd\u4f5c\u53ef\u80fd\u4f1a\u56e0\u4e3a\u5e76\u53d1\u51b2\u7a81\u800c\u5931\u8d25\uff0c\u56e0\u6b64\u901a\u5e38\u4f1a\u4e0ewhile\u5faa\u73af\u642d\u914d\u4f7f\u7528\uff0c\u5728\u5931\u8d25\u540e\u4e0d\u65ad\u91cd\u8bd5\uff0c\u76f4\u5230\u64cd\u4f5c\u6210\u529f\u3002\u8fd9\u5c31\u662f <strong>\u81ea\u65cb\u9501\u673a\u5236<\/strong> \u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"CAS_%E7%AE%97%E6%B3%95%E5%AD%98%E5%9C%A8%E5%93%AA%E4%BA%9B%E9%97%AE%E9%A2%98%EF%BC%9F\"><\/span>CAS \u7b97\u6cd5\u5b58\u5728\u54ea\u4e9b\u95ee\u9898\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>ABA \u95ee\u9898\u662f CAS \u7b97\u6cd5\u6700\u5e38\u89c1\u7684\u95ee\u9898\u3002<\/p>\n<h4><span class=\"ez-toc-section\" id=\"ABA_%E9%97%AE%E9%A2%98\"><\/span>ABA \u95ee\u9898<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>\u5982\u679c\u4e00\u4e2a\u53d8\u91cf V \u521d\u6b21\u8bfb\u53d6\u7684\u65f6\u5019\u662f A \u503c\uff0c\u5e76\u4e14\u5728\u51c6\u5907\u8d4b\u503c\u7684\u65f6\u5019\u68c0\u67e5\u5230\u5b83\u4ecd\u7136\u662f A \u503c\uff0c\u90a3\u6211\u4eec\u5c31\u80fd\u8bf4\u660e\u5b83\u7684\u503c\u6ca1\u6709\u88ab\u5176\u4ed6\u7ebf\u7a0b\u4fee\u6539\u8fc7\u4e86\u5417\uff1f\u5f88\u660e\u663e\u662f\u4e0d\u80fd\u7684\uff0c\u56e0\u4e3a\u5728\u8fd9\u6bb5\u65f6\u95f4\u5b83\u7684\u503c\u53ef\u80fd\u88ab\u6539\u4e3a\u5176\u4ed6\u503c\uff0c\u7136\u540e\u53c8\u6539\u56de A\uff0c\u90a3 CAS \u64cd\u4f5c\u5c31\u4f1a\u8bef\u8ba4\u4e3a\u5b83\u4ece\u6765\u6ca1\u6709\u88ab\u4fee\u6539\u8fc7\u3002\u8fd9\u4e2a\u95ee\u9898\u88ab\u79f0\u4e3a CAS \u64cd\u4f5c\u7684 <strong>&quot;ABA&quot;\u95ee\u9898<\/strong>\u3002<\/p>\n<p>ABA \u95ee\u9898\u7684\u89e3\u51b3\u601d\u8def\u662f\u5728\u53d8\u91cf\u524d\u9762\u8ffd\u52a0\u4e0a<strong>\u7248\u672c\u53f7\u6216\u8005\u65f6\u95f4\u6233<\/strong>\u3002JDK 1.5 \u4ee5\u540e\u7684 AtomicStampedReference \u7c7b\u5c31\u662f\u7528\u6765\u89e3\u51b3 ABA \u95ee\u9898\u7684\uff0c\u5176\u4e2d\u7684 compareAndSet() \u65b9\u6cd5\u5c31\u662f\u9996\u5148\u68c0\u67e5\u5f53\u524d\u5f15\u7528\u662f\u5426\u7b49\u4e8e\u9884\u671f\u5f15\u7528\uff0c\u5e76\u4e14\u5f53\u524d\u6807\u5fd7\u662f\u5426\u7b49\u4e8e\u9884\u671f\u6807\u5fd7\uff0c\u5982\u679c\u5168\u90e8\u76f8\u7b49\uff0c\u5219\u4ee5\u539f\u5b50\u65b9\u5f0f\u5c06\u8be5\u5f15\u7528\u548c\u8be5\u6807\u5fd7\u7684\u503c\u8bbe\u7f6e\u4e3a\u7ed9\u5b9a\u7684\u66f4\u65b0\u503c\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public boolean compareAndSet(V   expectedReference,\n                             V   newReference,\n                             int expectedStamp,\n                             int newStamp) {\n    Pair&lt;V&gt; current = pair;\n    return\n        expectedReference == current.reference &amp;&amp;\n        expectedStamp == current.stamp &amp;&amp;\n        ((newReference == current.reference &amp;&amp;\n          newStamp == current.stamp) ||\n         casPair(current, Pair.of(newReference, newStamp)));\n}<\/code><\/pre>\n<h4><span class=\"ez-toc-section\" id=\"%E5%BE%AA%E7%8E%AF%E6%97%B6%E9%97%B4%E9%95%BF%E5%BC%80%E9%94%80%E5%A4%A7\"><\/span>\u5faa\u73af\u65f6\u95f4\u957f\u5f00\u9500\u5927<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>CAS \u7ecf\u5e38\u4f1a\u7528\u5230\u81ea\u65cb\u64cd\u4f5c\u6765\u8fdb\u884c\u91cd\u8bd5\uff0c\u4e5f\u5c31\u662f\u4e0d\u6210\u529f\u5c31\u4e00\u76f4\u5faa\u73af\u6267\u884c\u76f4\u5230\u6210\u529f\u3002\u5982\u679c\u957f\u65f6\u95f4\u4e0d\u6210\u529f\uff0c\u4f1a\u7ed9 CPU \u5e26\u6765\u975e\u5e38\u5927\u7684\u6267\u884c\u5f00\u9500\u3002<\/p>\n<p>\u5982\u679c JVM \u80fd\u591f\u652f\u6301\u5904\u7406\u5668\u63d0\u4f9b\u7684pause\u6307\u4ee4\uff0c\u90a3\u4e48\u81ea\u65cb\u64cd\u4f5c\u7684\u6548\u7387\u5c06\u6709\u6240\u63d0\u5347\u3002pause\u6307\u4ee4\u6709\u4e24\u4e2a\u91cd\u8981\u4f5c\u7528\uff1a<\/p>\n<p>1\u3001<strong>\u5ef6\u8fdf\u6d41\u6c34\u7ebf\u6267\u884c\u6307\u4ee4\uff1a<\/strong>pause\u6307\u4ee4\u53ef\u4ee5\u5ef6\u8fdf\u6307\u4ee4\u7684\u6267\u884c\uff0c\u4ece\u800c\u51cf\u5c11 CPU \u7684\u8d44\u6e90\u6d88\u8017\u3002\u5177\u4f53\u7684\u5ef6\u8fdf\u65f6\u95f4\u53d6\u51b3\u4e8e\u5904\u7406\u5668\u7684\u5b9e\u73b0\u7248\u672c\uff0c\u5728\u67d0\u4e9b\u5904\u7406\u5668\u4e0a\uff0c\u5ef6\u8fdf\u65f6\u95f4\u53ef\u80fd\u4e3a\u96f6\u3002<br \/>\n2\u3001<strong>\u907f\u514d\u5185\u5b58\u987a\u5e8f\u51b2\u7a81<\/strong>\uff1a\u5728\u9000\u51fa\u5faa\u73af\u65f6\uff0cpause\u6307\u4ee4\u53ef\u4ee5\u907f\u514d\u7531\u4e8e\u5185\u5b58\u987a\u5e8f\u51b2\u7a81\u800c\u5bfc\u81f4\u7684 CPU \u6d41\u6c34\u7ebf\u88ab\u6e05\u7a7a\uff0c\u4ece\u800c\u63d0\u9ad8 CPU \u7684\u6267\u884c\u6548\u7387\u3002<\/p>\n<h4><span class=\"ez-toc-section\" id=\"%E5%8F%AA%E8%83%BD%E4%BF%9D%E8%AF%81%E4%B8%80%E4%B8%AA%E5%85%B1%E4%BA%AB%E5%8F%98%E9%87%8F%E7%9A%84%E5%8E%9F%E5%AD%90%E6%93%8D%E4%BD%9C\"><\/span>\u53ea\u80fd\u4fdd\u8bc1\u4e00\u4e2a\u5171\u4eab\u53d8\u91cf\u7684\u539f\u5b50\u64cd\u4f5c<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>CAS \u64cd\u4f5c\u4ec5\u80fd\u5bf9\u5355\u4e2a\u5171\u4eab\u53d8\u91cf\u6709\u6548\u3002\u5f53\u9700\u8981\u64cd\u4f5c\u591a\u4e2a\u5171\u4eab\u53d8\u91cf\u65f6\uff0cCAS \u5c31\u663e\u5f97\u65e0\u80fd\u4e3a\u529b\u3002\u4e0d\u8fc7\uff0c\u4ece JDK 1.5 \u5f00\u59cb\uff0cJava \u63d0\u4f9b\u4e86AtomicReference\u7c7b\uff0c\u8fd9\u4f7f\u5f97\u6211\u4eec\u80fd\u591f\u4fdd\u8bc1\u5f15\u7528\u5bf9\u8c61\u4e4b\u95f4\u7684\u539f\u5b50\u6027\u3002\u901a\u8fc7\u5c06\u591a\u4e2a\u53d8\u91cf\u5c01\u88c5\u5728\u4e00\u4e2a\u5bf9\u8c61\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528AtomicReference\u6765\u6267\u884c CAS \u64cd\u4f5c\u3002<\/p>\n<p>\u9664\u4e86 AtomicReference \u8fd9\u79cd\u65b9\u5f0f\u4e4b\u5916\uff0c\u8fd8\u53ef\u4ee5\u5229\u7528\u52a0\u9501\u6765\u4fdd\u8bc1\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"synchronized_%E6%98%AF%E4%BB%80%E4%B9%88%EF%BC%9F%E6%9C%89%E4%BB%80%E4%B9%88%E7%94%A8%EF%BC%9F\"><\/span>synchronized \u662f\u4ec0\u4e48\uff1f\u6709\u4ec0\u4e48\u7528\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>synchronized \u662f Java \u4e2d\u7684\u4e00\u4e2a\u5173\u952e\u5b57\uff0c\u7ffb\u8bd1\u6210\u4e2d\u6587\u662f\u540c\u6b65\u7684\u610f\u601d\uff0c\u4e3b\u8981\u89e3\u51b3\u7684\u662f\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u8bbf\u95ee\u8d44\u6e90\u7684\u540c\u6b65\u6027\uff0c\u53ef\u4ee5\u4fdd\u8bc1\u88ab\u5b83\u4fee\u9970\u7684\u65b9\u6cd5\u6216\u8005\u4ee3\u7801\u5757\u5728\u4efb\u610f\u65f6\u523b\u53ea\u80fd\u6709\u4e00\u4e2a\u7ebf\u7a0b\u6267\u884c\u3002<\/p>\n<p>\u5728 Java \u65e9\u671f\u7248\u672c\u4e2d\uff0csynchronized \u5c5e\u4e8e<strong> \u91cd\u91cf\u7ea7\u9501\uff0c<\/strong>\u6548\u7387\u4f4e\u4e0b\u3002\u8fd9\u662f\u56e0\u4e3a\u76d1\u89c6\u5668\u9501\uff08monitor\uff09\u662f\u4f9d\u8d56\u4e8e\u5e95\u5c42\u7684\u64cd\u4f5c\u7cfb\u7edf\u7684 Mutex Lock \u6765\u5b9e\u73b0\u7684\uff0cJava \u7684\u7ebf\u7a0b\u662f\u6620\u5c04\u5230\u64cd\u4f5c\u7cfb\u7edf\u7684\u539f\u751f\u7ebf\u7a0b\u4e4b\u4e0a\u7684\u3002\u5982\u679c\u8981\u6302\u8d77\u6216\u8005\u5524\u9192\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u90fd\u9700\u8981\u64cd\u4f5c\u7cfb\u7edf\u5e2e\u5fd9\u5b8c\u6210\uff0c\u800c\u64cd\u4f5c\u7cfb\u7edf\u5b9e\u73b0\u7ebf\u7a0b\u4e4b\u95f4\u7684\u5207\u6362\u65f6\u9700\u8981\u4ece\u7528\u6237\u6001\u8f6c\u6362\u5230\u5185\u6838\u6001\uff0c\u8fd9\u4e2a\u72b6\u6001\u4e4b\u95f4\u7684\u8f6c\u6362\u9700\u8981\u76f8\u5bf9\u6bd4\u8f83\u957f\u7684\u65f6\u95f4\uff0c\u65f6\u95f4\u6210\u672c\u76f8\u5bf9\u8f83\u9ad8\u3002<\/p>\n<p>\u4e0d\u8fc7\uff0c\u5728 Java 6 \u4e4b\u540e\uff0c synchronized \u5f15\u5165\u4e86\u5927\u91cf\u7684\u4f18\u5316\u5982\u81ea\u65cb\u9501\u3001\u9002\u5e94\u6027\u81ea\u65cb\u9501\u3001\u9501\u6d88\u9664\u3001\u9501\u7c97\u5316\u3001\u504f\u5411\u9501\u3001\u8f7b\u91cf\u7ea7\u9501\u7b49\u6280\u672f\u6765\u51cf\u5c11\u9501\u64cd\u4f5c\u7684\u5f00\u9500\uff0c\u8fd9\u4e9b\u4f18\u5316\u8ba9 synchronized \u9501\u7684\u6548\u7387\u63d0\u5347\u4e86\u5f88\u591a\u3002\u56e0\u6b64\uff0c synchronized \u8fd8\u662f\u53ef\u4ee5\u5728\u5b9e\u9645\u9879\u76ee\u4e2d\u4f7f\u7528\u7684\uff0c\u50cf JDK \u6e90\u7801\u3001\u5f88\u591a\u5f00\u6e90\u6846\u67b6\u90fd\u5927\u91cf\u4f7f\u7528\u4e86 synchronized \u3002<\/p>\n<p>\u5173\u4e8e\u504f\u5411\u9501\u591a\u8865\u5145\u4e00\u70b9\uff1a\u7531\u4e8e\u504f\u5411\u9501\u589e\u52a0\u4e86 JVM \u7684\u590d\u6742\u6027\uff0c\u540c\u65f6\u4e5f\u5e76\u6ca1\u6709\u4e3a\u6240\u6709\u5e94\u7528\u90fd\u5e26\u6765\u6027\u80fd\u63d0\u5347\u3002\u56e0\u6b64\uff0c\u5728 JDK15 \u4e2d\uff0c\u504f\u5411\u9501\u88ab\u9ed8\u8ba4\u5173\u95ed\uff08\u4ecd\u7136\u53ef\u4ee5\u4f7f\u7528 -XX:+UseBiasedLocking \u542f\u7528\u504f\u5411\u9501\uff09\uff0c\u5728 JDK18 \u4e2d\uff0c\u504f\u5411\u9501\u5df2\u7ecf\u88ab\u5f7b\u5e95\u5e9f\u5f03\uff08\u65e0\u6cd5\u901a\u8fc7\u547d\u4ee4\u884c\u6253\u5f00\uff09\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8_synchronized%EF%BC%9F\"><\/span>\u5982\u4f55\u4f7f\u7528 synchronized\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>synchronized \u5173\u952e\u5b57\u7684\u4f7f\u7528\u65b9\u5f0f\u4e3b\u8981\u6709\u4e0b\u9762 3 \u79cd\uff1a<\/p>\n<p>1\u3001\u4fee\u9970\u5b9e\u4f8b\u65b9\u6cd5<br \/>\n2\u3001\u4fee\u9970\u9759\u6001\u65b9\u6cd5<br \/>\n3\u3001\u4fee\u9970\u4ee3\u7801\u5757<\/p>\n<p><strong>1\u3001\u4fee\u9970\u5b9e\u4f8b\u65b9\u6cd5 \uff08\u9501\u5f53\u524d\u5bf9\u8c61\u5b9e\u4f8b\uff09<\/strong><br \/>\n\u7ed9\u5f53\u524d\u5bf9\u8c61\u5b9e\u4f8b\u52a0\u9501\uff0c\u8fdb\u5165\u540c\u6b65\u4ee3\u7801\u524d\u8981\u83b7\u5f97 <strong>\u5f53\u524d\u5bf9\u8c61\u5b9e\u4f8b\u7684\u9501 <\/strong>\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">synchronized void method() {\n    \/\/\u4e1a\u52a1\u4ee3\u7801\n}<\/code><\/pre>\n<p><strong>2\u3001\u4fee\u9970\u9759\u6001\u65b9\u6cd5 \uff08\u9501\u5f53\u524d\u7c7b\uff09<\/strong><\/p>\n<p>\u7ed9\u5f53\u524d\u7c7b\u52a0\u9501\uff0c\u4f1a\u4f5c\u7528\u4e8e\u7c7b\u7684\u6240\u6709\u5bf9\u8c61\u5b9e\u4f8b \uff0c\u8fdb\u5165\u540c\u6b65\u4ee3\u7801\u524d\u8981\u83b7\u5f97 <strong>\u5f53\u524d class \u7684\u9501\u3002<\/strong><\/p>\n<p>\u8fd9\u662f\u56e0\u4e3a\u9759\u6001\u6210\u5458\u4e0d\u5c5e\u4e8e\u4efb\u4f55\u4e00\u4e2a\u5b9e\u4f8b\u5bf9\u8c61\uff0c\u5f52\u6574\u4e2a\u7c7b\u6240\u6709\uff0c\u4e0d\u4f9d\u8d56\u4e8e\u7c7b\u7684\u7279\u5b9a\u5b9e\u4f8b\uff0c\u88ab\u7c7b\u7684\u6240\u6709\u5b9e\u4f8b\u5171\u4eab\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">synchronized static void method() {\n    \/\/\u4e1a\u52a1\u4ee3\u7801\n}<\/code><\/pre>\n<p>\u9759\u6001 synchronized \u65b9\u6cd5\u548c\u975e\u9759\u6001 synchronized \u65b9\u6cd5\u4e4b\u95f4\u7684\u8c03\u7528\u4e92\u65a5\u4e48\uff1f\u4e0d\u4e92\u65a5\uff01\u5982\u679c\u4e00\u4e2a\u7ebf\u7a0b A \u8c03\u7528\u4e00\u4e2a\u5b9e\u4f8b\u5bf9\u8c61\u7684\u975e\u9759\u6001 synchronized \u65b9\u6cd5\uff0c\u800c\u7ebf\u7a0b B \u9700\u8981\u8c03\u7528\u8fd9\u4e2a\u5b9e\u4f8b\u5bf9\u8c61\u6240\u5c5e\u7c7b\u7684\u9759\u6001 synchronized \u65b9\u6cd5\uff0c\u662f\u5141\u8bb8\u7684\uff0c\u4e0d\u4f1a\u53d1\u751f\u4e92\u65a5\u73b0\u8c61\uff0c\u56e0\u4e3a\u8bbf\u95ee\u9759\u6001 synchronized \u65b9\u6cd5\u5360\u7528\u7684\u9501\u662f\u5f53\u524d\u7c7b\u7684\u9501\uff0c\u800c\u8bbf\u95ee\u975e\u9759\u6001 synchronized \u65b9\u6cd5\u5360\u7528\u7684\u9501\u662f\u5f53\u524d\u5b9e\u4f8b\u5bf9\u8c61\u9501\u3002<\/p>\n<p><strong>3\u3001\u4fee\u9970\u4ee3\u7801\u5757 \uff08\u9501\u6307\u5b9a\u5bf9\u8c61\/\u7c7b\uff09<\/strong><br \/>\n<strong>\u5bf9\u62ec\u53f7\u91cc\u6307\u5b9a\u7684\u5bf9\u8c61\/\u7c7b\u52a0\u9501\uff1a<\/strong><br \/>\nsynchronized(object) \u8868\u793a\u8fdb\u5165\u540c\u6b65\u4ee3\u7801\u5757\u524d\u8981\u83b7\u5f97 \u7ed9\u5b9a\u5bf9\u8c61\u7684\u9501\u3002<br \/>\nsynchronized(\u7c7b.class) \u8868\u793a\u8fdb\u5165\u540c\u6b65\u4ee3\u7801\u5757\u524d\u8981\u83b7\u5f97 \u7ed9\u5b9a Class \u7684\u9501<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">synchronized(this) {\n    \/\/\u4e1a\u52a1\u4ee3\u7801\n}<\/code><\/pre>\n<p><strong>\u603b\u7ed3\uff1a<\/strong>synchronized \u5173\u952e\u5b57\u52a0\u5230 static \u9759\u6001\u65b9\u6cd5\u548c synchronized(class) \u4ee3\u7801\u5757\u4e0a\u90fd\u662f\u662f\u7ed9 Class \u7c7b\u4e0a\u9501\uff1b<br \/>\nsynchronized \u5173\u952e\u5b57\u52a0\u5230\u5b9e\u4f8b\u65b9\u6cd5\u4e0a\u662f\u7ed9\u5bf9\u8c61\u5b9e\u4f8b\u4e0a\u9501\uff1b<br \/>\n\u5c3d\u91cf\u4e0d\u8981\u4f7f\u7528 synchronized(String a) \u56e0\u4e3a JVM \u4e2d\uff0c\u5b57\u7b26\u4e32\u5e38\u91cf\u6c60\u5177\u6709\u7f13\u5b58\u529f\u80fd<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E6%9E%84%E9%80%A0%E6%96%B9%E6%B3%95%E5%8F%AF%E4%BB%A5%E7%94%A8_synchronized_%E4%BF%AE%E9%A5%B0%E4%B9%88%EF%BC%9F\"><\/span>\u6784\u9020\u65b9\u6cd5\u53ef\u4ee5\u7528 synchronized \u4fee\u9970\u4e48\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u6784\u9020\u65b9\u6cd5\u4e0d\u80fd\u4f7f\u7528 synchronized \u5173\u952e\u5b57\u4fee\u9970\u3002\u4e0d\u8fc7\uff0c\u53ef\u4ee5\u5728\u6784\u9020\u65b9\u6cd5\u5185\u90e8\u4f7f\u7528 synchronized \u4ee3\u7801\u5757\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u6784\u9020\u65b9\u6cd5\u672c\u8eab\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u4f46\u5982\u679c\u5728\u6784\u9020\u65b9\u6cd5\u4e2d\u6d89\u53ca\u5230\u5171\u4eab\u8d44\u6e90\u7684\u64cd\u4f5c\uff0c\u5c31\u9700\u8981\u91c7\u53d6\u9002\u5f53\u7684\u540c\u6b65\u63aa\u65bd\u6765\u4fdd\u8bc1\u6574\u4e2a\u6784\u9020\u8fc7\u7a0b\u7684\u7ebf\u7a0b\u5b89\u5168\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"synchronized_%E5%BA%95%E5%B1%82%E5%8E%9F%E7%90%86%E4%BA%86%E8%A7%A3%E5%90%97%EF%BC%9F\"><\/span>synchronized \u5e95\u5c42\u539f\u7406\u4e86\u89e3\u5417\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>synchronized \u5173\u952e\u5b57\u5e95\u5c42\u539f\u7406\u5c5e\u4e8e JVM \u5c42\u9762\u7684\u4e1c\u897f\u3002<\/p>\n<p>synchronized \u540c\u6b65\u8bed\u53e5\u5757\u7684\u60c5\u51b5<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class SynchronizedDemo {\n    public void method() {\n        synchronized (this) {\n            System.out.println(&quot;synchronized \u4ee3\u7801\u5757&quot;);\n        }\n    }\n}<\/code><\/pre>\n<p>\u901a\u8fc7 JDK \u81ea\u5e26\u7684 javap \u547d\u4ee4\u67e5\u770b SynchronizedDemo \u7c7b\u7684\u76f8\u5173\u5b57\u8282\u7801\u4fe1\u606f\uff1a\u9996\u5148\u5207\u6362\u5230\u7c7b\u7684\u5bf9\u5e94\u76ee\u5f55\u6267\u884c javac SynchronizedDemo.java \u547d\u4ee4\u751f\u6210\u7f16\u8bd1\u540e\u7684 .class \u6587\u4ef6\uff0c\u7136\u540e\u6267\u884cjavap -c -s -v -l SynchronizedDemo.class\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395162750.png\" alt=\"file\" \/><\/p>\n<p>\u4ece\u4e0a\u9762\u6211\u4eec\u53ef\u4ee5\u770b\u51fa<strong>\uff1asynchronized \u540c\u6b65\u8bed\u53e5\u5757\u7684\u5b9e\u73b0\u4f7f\u7528\u7684\u662f monitorenter \u548c monitorexit \u6307\u4ee4\uff0c\u5176\u4e2d monitorenter \u6307\u4ee4\u6307\u5411\u540c\u6b65\u4ee3\u7801\u5757\u7684\u5f00\u59cb\u4f4d\u7f6e\uff0cmonitorexit \u6307\u4ee4\u5219\u6307\u660e\u540c\u6b65\u4ee3\u7801\u5757\u7684\u7ed3\u675f\u4f4d\u7f6e\u3002<\/strong><\/p>\n<p>\u4e0a\u9762\u7684\u5b57\u8282\u7801\u4e2d\u5305\u542b\u4e00\u4e2a monitorenter \u6307\u4ee4\u4ee5\u53ca\u4e24\u4e2a monitorexit \u6307\u4ee4\uff0c\u8fd9\u662f\u4e3a\u4e86\u4fdd\u8bc1\u9501\u5728\u540c\u6b65\u4ee3\u7801\u5757\u4ee3\u7801\u6b63\u5e38\u6267\u884c\u4ee5\u53ca\u51fa\u73b0\u5f02\u5e38\u7684\u8fd9\u4e24\u79cd\u60c5\u51b5\u4e0b\u90fd\u80fd\u88ab\u6b63\u786e\u91ca\u653e\u3002<\/p>\n<p>\u5f53\u6267\u884c monitorenter \u6307\u4ee4\u65f6\uff0c\u7ebf\u7a0b\u8bd5\u56fe\u83b7\u53d6\u9501\u4e5f\u5c31\u662f\u83b7\u53d6 <strong>\u5bf9\u8c61\u76d1\u89c6\u5668 monitor <\/strong>\u7684\u6301\u6709\u6743\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395211019.png\" alt=\"file\" \/><\/p>\n<p>\u5728\u6267\u884cmonitorenter\u65f6\uff0c\u4f1a\u5c1d\u8bd5\u83b7\u53d6\u5bf9\u8c61\u7684\u9501\uff0c\u5982\u679c\u9501\u7684\u8ba1\u6570\u5668\u4e3a 0 \u5219\u8868\u793a\u9501\u53ef\u4ee5\u88ab\u83b7\u53d6\uff0c\u83b7\u53d6\u540e\u5c06\u9501\u8ba1\u6570\u5668\u8bbe\u4e3a 1 \u4e5f\u5c31\u662f\u52a0 1\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395234185.png\" alt=\"file\" \/><\/p>\n<p>\u5bf9\u8c61\u9501\u7684\u62e5\u6709\u8005\u7ebf\u7a0b\u624d\u53ef\u4ee5\u6267\u884c monitorexit \u6307\u4ee4\u6765\u91ca\u653e\u9501\u3002\u5728\u6267\u884c monitorexit \u6307\u4ee4\u540e\uff0c\u5c06\u9501\u8ba1\u6570\u5668\u8bbe\u4e3a 0\uff0c\u8868\u660e\u9501\u88ab\u91ca\u653e\uff0c\u5176\u4ed6\u7ebf\u7a0b\u53ef\u4ee5\u5c1d\u8bd5\u83b7\u53d6\u9501\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395250251.png\" alt=\"file\" \/><\/p>\n<p>\u5982\u679c\u83b7\u53d6\u5bf9\u8c61\u9501\u5931\u8d25\uff0c\u90a3\u5f53\u524d\u7ebf\u7a0b\u5c31\u8981\u963b\u585e\u7b49\u5f85\uff0c\u76f4\u5230\u9501\u88ab\u53e6\u5916\u4e00\u4e2a\u7ebf\u7a0b\u91ca\u653e\u4e3a\u6b62\u3002<\/p>\n<p>synchronized \u4fee\u9970\u65b9\u6cd5\u7684\u60c5\u51b5<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class SynchronizedDemo2 {\n    public synchronized void method() {\n        System.out.println(&quot;synchronized \u65b9\u6cd5&quot;);\n    }\n}<\/code><\/pre>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395282613.png\" alt=\"file\" \/><\/p>\n<p>synchronized \u4fee\u9970\u7684\u65b9\u6cd5\u5e76\u6ca1\u6709 monitorenter \u6307\u4ee4\u548c monitorexit \u6307\u4ee4\uff0c\u53d6\u800c\u4ee3\u4e4b\u7684\u662f ACC_SYNCHRONIZED \u6807\u8bc6\uff0c\u8be5\u6807\u8bc6\u6307\u660e\u4e86\u8be5\u65b9\u6cd5\u662f\u4e00\u4e2a\u540c\u6b65\u65b9\u6cd5\u3002JVM \u901a\u8fc7\u8be5 ACC_SYNCHRONIZED \u8bbf\u95ee\u6807\u5fd7\u6765\u8fa8\u522b\u4e00\u4e2a\u65b9\u6cd5\u662f\u5426\u58f0\u660e\u4e3a\u540c\u6b65\u65b9\u6cd5\uff0c\u4ece\u800c\u6267\u884c\u76f8\u5e94\u7684\u540c\u6b65\u8c03\u7528\u3002<\/p>\n<p>\u5982\u679c\u662f\u5b9e\u4f8b\u65b9\u6cd5\uff0cJVM \u4f1a\u5c1d\u8bd5\u83b7\u53d6\u5b9e\u4f8b\u5bf9\u8c61\u7684\u9501\u3002\u5982\u679c\u662f\u9759\u6001\u65b9\u6cd5\uff0cJVM \u4f1a\u5c1d\u8bd5\u83b7\u53d6\u5f53\u524d class \u7684\u9501\u3002<\/p>\n<p><strong>\u603b\u7ed3<\/strong>\uff1a<br \/>\nsynchronized \u540c\u6b65\u8bed\u53e5\u5757\u7684\u5b9e\u73b0\u4f7f\u7528\u7684\u662f monitorenter \u548c monitorexit \u6307\u4ee4\uff0c\u5176\u4e2d monitorenter \u6307\u4ee4\u6307\u5411\u540c\u6b65\u4ee3\u7801\u5757\u7684\u5f00\u59cb\u4f4d\u7f6e\uff0cmonitorexit \u6307\u4ee4\u5219\u6307\u660e\u540c\u6b65\u4ee3\u7801\u5757\u7684\u7ed3\u675f\u4f4d\u7f6e\u3002<br \/>\nsynchronized \u4fee\u9970\u7684\u65b9\u6cd5\u5e76\u6ca1\u6709 monitorenter \u6307\u4ee4\u548c monitorexit \u6307\u4ee4\uff0c\u53d6\u800c\u4ee3\u4e4b\u7684\u662f ACC_SYNCHRONIZED \u6807\u8bc6\uff0c\u8be5\u6807\u8bc6\u6307\u660e\u4e86\u8be5\u65b9\u6cd5\u662f\u4e00\u4e2a\u540c\u6b65\u65b9\u6cd5\u3002<\/p>\n<p><strong>\u4e0d\u8fc7\uff0c\u4e24\u8005\u7684\u672c\u8d28\u90fd\u662f\u5bf9\u5bf9\u8c61\u76d1\u89c6\u5668 monitor \u7684\u83b7\u53d6\u3002<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"JDK16_%E4%B9%8B%E5%90%8E%E7%9A%84_synchronized_%E5%BA%95%E5%B1%82%E5%81%9A%E4%BA%86%E5%93%AA%E4%BA%9B%E4%BC%98%E5%8C%96%EF%BC%9F%E9%94%81%E5%8D%87%E7%BA%A7%E5%8E%9F%E7%90%86%E4%BA%86%E8%A7%A3%E5%90%97%EF%BC%9F\"><\/span>JDK1.6 \u4e4b\u540e\u7684 synchronized \u5e95\u5c42\u505a\u4e86\u54ea\u4e9b\u4f18\u5316\uff1f\u9501\u5347\u7ea7\u539f\u7406\u4e86\u89e3\u5417\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5728 Java 6 \u4e4b\u540e\uff0c synchronized \u5f15\u5165\u4e86\u5927\u91cf\u7684\u4f18\u5316\u5982\u81ea\u65cb\u9501\u3001\u9002\u5e94\u6027\u81ea\u65cb\u9501\u3001\u9501\u6d88\u9664\u3001\u9501\u7c97\u5316\u3001\u504f\u5411\u9501\u3001\u8f7b\u91cf\u7ea7\u9501\u7b49\u6280\u672f\u6765\u51cf\u5c11\u9501\u64cd\u4f5c\u7684\u5f00\u9500\uff0c\u8fd9\u4e9b\u4f18\u5316\u8ba9 synchronized \u9501\u7684\u6548\u7387\u63d0\u5347\u4e86\u5f88\u591a\uff08JDK18 \u4e2d\uff0c\u504f\u5411\u9501\u5df2\u7ecf\u88ab\u5f7b\u5e95\u5e9f\u5f03\uff0c\u524d\u9762\u5df2\u7ecf\u63d0\u5230\u8fc7\u4e86\uff09\u3002<\/p>\n<p>\u9501\u4e3b\u8981\u5b58\u5728\u56db\u79cd\u72b6\u6001\uff0c\u4f9d\u6b21\u662f\uff1a<strong>\u65e0\u9501\u72b6\u6001\u3001\u504f\u5411\u9501\u72b6\u6001\u3001\u8f7b\u91cf\u7ea7\u9501\u72b6\u6001\u3001\u91cd\u91cf\u7ea7\u9501\u72b6\u6001<\/strong>\uff0c\u4ed6\u4eec\u4f1a\u968f\u7740\u7ade\u4e89\u7684\u6fc0\u70c8\u800c\u9010\u6e10\u5347\u7ea7\u3002\u6ce8\u610f\u9501\u53ef\u4ee5\u5347\u7ea7\u4e0d\u53ef\u964d\u7ea7\uff0c\u8fd9\u79cd\u7b56\u7565\u662f\u4e3a\u4e86\u63d0\u9ad8\u83b7\u5f97\u9501\u548c\u91ca\u653e\u9501\u7684\u6548\u7387\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"synchronized_%E7%9A%84%E5%81%8F%E5%90%91%E9%94%81%E4%B8%BA%E4%BB%80%E4%B9%88%E8%A2%AB%E5%BA%9F%E5%BC%83%E4%BA%86%EF%BC%9F\"><\/span>synchronized \u7684\u504f\u5411\u9501\u4e3a\u4ec0\u4e48\u88ab\u5e9f\u5f03\u4e86\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u6027\u80fd\u6536\u76ca\u4e0d\u660e\u663e\uff1a<\/strong><br \/>\n\u504f\u5411\u9501\u662f HotSpot \u865a\u62df\u673a\u7684\u4e00\u9879\u4f18\u5316\u6280\u672f\uff0c\u53ef\u4ee5\u63d0\u5347\u5355\u7ebf\u7a0b\u5bf9\u540c\u6b65\u4ee3\u7801\u5757\u7684\u8bbf\u95ee\u6027\u80fd\u3002\u53d7\u76ca\u4e8e\u504f\u5411\u9501\u7684\u5e94\u7528\u7a0b\u5e8f\u901a\u5e38\u4f7f\u7528\u4e86\u65e9\u671f\u7684 Java \u96c6\u5408 API\uff0c\u4f8b\u5982 HashTable\u3001Vector\uff0c\u5728\u8fd9\u4e9b\u96c6\u5408\u7c7b\u4e2d\u901a\u8fc7 synchronized \u6765\u63a7\u5236\u540c\u6b65\uff0c\u8fd9\u6837\u5728\u5355\u7ebf\u7a0b\u9891\u7e41\u8bbf\u95ee\u65f6\uff0c\u901a\u8fc7\u504f\u5411\u9501\u4f1a\u51cf\u5c11\u540c\u6b65\u5f00\u9500\u3002\u968f\u7740 JDK \u7684\u53d1\u5c55\uff0c\u51fa\u73b0\u4e86 ConcurrentHashMap \u9ad8\u6027\u80fd\u7684\u96c6\u5408\u7c7b\uff0c\u5728\u96c6\u5408\u7c7b\u5185\u90e8\u8fdb\u884c\u4e86\u8bb8\u591a\u6027\u80fd\u4f18\u5316\uff0c\u6b64\u65f6\u504f\u5411\u9501\u5e26\u6765\u7684\u6027\u80fd\u6536\u76ca\u5c31\u4e0d\u660e\u663e\u4e86\u3002\u504f\u5411\u9501\u4ec5\u4ec5\u5728\u5355\u7ebf\u7a0b\u8bbf\u95ee\u540c\u6b65\u4ee3\u7801\u5757\u7684\u573a\u666f\u4e2d\u53ef\u4ee5\u83b7\u5f97\u6027\u80fd\u6536\u76ca\u3002\u5982\u679c\u5b58\u5728\u591a\u7ebf\u7a0b\u7ade\u4e89\uff0c\u5c31\u9700\u8981 \u64a4\u9500\u504f\u5411\u9501 \uff0c\u8fd9\u4e2a\u64cd\u4f5c\u7684\u6027\u80fd\u5f00\u9500\u662f\u6bd4\u8f83\u6602\u8d35\u7684\u3002\u504f\u5411\u9501\u7684\u64a4\u9500\u9700\u8981\u7b49\u5f85\u8fdb\u5165\u5230\u5168\u5c40\u5b89\u5168\u70b9\uff08safe point\uff09\uff0c\u8be5\u72b6\u6001\u4e0b\u6240\u6709\u7ebf\u7a0b\u90fd\u662f\u6682\u505c\u7684\uff0c\u6b64\u65f6\u53bb\u68c0\u67e5\u7ebf\u7a0b\u72b6\u6001\u5e76\u8fdb\u884c\u504f\u5411\u9501\u7684\u64a4\u9500\u3002<br \/>\n<strong>JVM \u5185\u90e8\u4ee3\u7801\u7ef4\u62a4\u6210\u672c\u592a\u9ad8\uff1a<\/strong><br \/>\n\u504f\u5411\u9501\u5c06\u8bb8\u591a\u590d\u6742\u4ee3\u7801\u5f15\u5165\u5230\u540c\u6b65\u5b50\u7cfb\u7edf\uff0c\u5e76\u4e14\u5bf9\u5176\u4ed6\u7684 HotSpot \u7ec4\u4ef6\u4e5f\u5177\u6709\u4fb5\u5165\u6027\u3002\u8fd9\u79cd\u590d\u6742\u6027\u4e3a\u7406\u89e3\u4ee3\u7801\u3001\u7cfb\u7edf\u91cd\u6784\u5e26\u6765\u4e86\u56f0\u96be\uff0c\u56e0\u6b64\uff0c OpenJDK \u5b98\u65b9\u5e0c\u671b\u7981\u7528\u3001\u5e9f\u5f03\u5e76\u5220\u9664\u504f\u5411\u9501\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"synchronized_%E5%92%8C_volatile_%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\"><\/span>synchronized \u548c volatile \u6709\u4ec0\u4e48\u533a\u522b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>1\u3001synchronized \u5173\u952e\u5b57\u548c volatile \u5173\u952e\u5b57\u662f\u4e24\u4e2a\u4e92\u8865\u7684\u5b58\u5728\uff0c\u800c\u4e0d\u662f\u5bf9\u7acb\u7684\u5b58\u5728\uff01<br \/>\n2\u3001volatile \u5173\u952e\u5b57\u662f\u7ebf\u7a0b\u540c\u6b65\u7684\u8f7b\u91cf\u7ea7\u5b9e\u73b0\uff0c\u6240\u4ee5 volatile\u6027\u80fd\u80af\u5b9a\u6bd4synchronized\u5173\u952e\u5b57\u8981\u597d \u3002\u4f46\u662f volatile \u5173\u952e\u5b57\u53ea\u80fd\u7528\u4e8e\u53d8\u91cf\u800c synchronized \u5173\u952e\u5b57\u53ef\u4ee5\u4fee\u9970\u65b9\u6cd5\u4ee5\u53ca\u4ee3\u7801\u5757 \u3002<br \/>\n3\u3001volatile \u5173\u952e\u5b57\u80fd\u4fdd\u8bc1\u6570\u636e\u7684\u53ef\u89c1\u6027\uff0c\u4f46\u4e0d\u80fd\u4fdd\u8bc1\u6570\u636e\u7684\u539f\u5b50\u6027\u3002synchronized \u5173\u952e\u5b57\u4e24\u8005\u90fd\u80fd\u4fdd\u8bc1\u3002<br \/>\n4\u3001volatile\u5173\u952e\u5b57\u4e3b\u8981\u7528\u4e8e\u89e3\u51b3\u53d8\u91cf\u5728\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u53ef\u89c1\u6027\uff0c\u800c synchronized \u5173\u952e\u5b57\u89e3\u51b3\u7684\u662f\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u8bbf\u95ee\u8d44\u6e90\u7684\u540c\u6b65\u6027\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"ReentrantLock_%E6%98%AF%E4%BB%80%E4%B9%88%EF%BC%9F\"><\/span>ReentrantLock \u662f\u4ec0\u4e48\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>ReentrantLock \u5b9e\u73b0\u4e86 Lock \u63a5\u53e3\uff0c\u662f\u4e00\u4e2a\u53ef\u91cd\u5165\u4e14\u72ec\u5360\u5f0f\u7684\u9501\uff0c\u548c synchronized \u5173\u952e\u5b57\u7c7b\u4f3c\u3002\u4e0d\u8fc7\uff0cReentrantLock \u66f4\u7075\u6d3b\u3001\u66f4\u5f3a\u5927\uff0c\u589e\u52a0\u4e86\u8f6e\u8be2\u3001\u8d85\u65f6\u3001\u4e2d\u65ad\u3001\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u7b49\u9ad8\u7ea7\u529f\u80fd\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class ReentrantLock implements Lock, java.io.Serializable {}<\/code><\/pre>\n<p>ReentrantLock \u91cc\u9762\u6709\u4e00\u4e2a\u5185\u90e8\u7c7b Sync\uff0cSync \u7ee7\u627f AQS\uff08AbstractQueuedSynchronizer\uff09\uff0c\u6dfb\u52a0\u9501\u548c\u91ca\u653e\u9501\u7684\u5927\u90e8\u5206\u64cd\u4f5c\u5b9e\u9645\u4e0a\u90fd\u662f\u5728 Sync \u4e2d\u5b9e\u73b0\u7684\u3002Sync \u6709\u516c\u5e73\u9501 FairSync \u548c\u975e\u516c\u5e73\u9501 NonfairSync \u4e24\u4e2a\u5b50\u7c7b\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395546110.png\" alt=\"file\" \/><\/p>\n<p>ReentrantLock \u9ed8\u8ba4\u4f7f\u7528\u975e\u516c\u5e73\u9501\uff0c\u4e5f\u53ef\u4ee5\u901a\u8fc7\u6784\u9020\u5668\u6765\u663e\u5f0f\u7684\u6307\u5b9a\u4f7f\u7528\u516c\u5e73\u9501\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">\/\/ \u4f20\u5165\u4e00\u4e2a boolean \u503c\uff0ctrue \u65f6\u4e3a\u516c\u5e73\u9501\uff0cfalse \u65f6\u4e3a\u975e\u516c\u5e73\u9501\npublic ReentrantLock(boolean fair) {\n    sync = fair ? new FairSync() : new NonfairSync();\n}<\/code><\/pre>\n<p>\u4ece\u4e0a\u9762\u7684\u5185\u5bb9\u53ef\u4ee5\u770b\u51fa\uff0c ReentrantLock \u7684\u5e95\u5c42\u5c31\u662f\u7531 AQS \u6765\u5b9e\u73b0\u7684<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%85%AC%E5%B9%B3%E9%94%81%E5%92%8C%E9%9D%9E%E5%85%AC%E5%B9%B3%E9%94%81%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\"><\/span>\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u6709\u4ec0\u4e48\u533a\u522b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u516c\u5e73\u9501 :<\/strong> \u9501\u88ab\u91ca\u653e\u4e4b\u540e\uff0c\u5148\u7533\u8bf7\u7684\u7ebf\u7a0b\u5148\u5f97\u5230\u9501\u3002\u6027\u80fd\u8f83\u5dee\u4e00\u4e9b\uff0c\u56e0\u4e3a\u516c\u5e73\u9501\u4e3a\u4e86\u4fdd\u8bc1\u65f6\u95f4\u4e0a\u7684\u7edd\u5bf9\u987a\u5e8f\uff0c\u4e0a\u4e0b\u6587\u5207\u6362\u66f4\u9891\u7e41\u3002<\/p>\n<p><strong>\u975e\u516c\u5e73\u9501\uff1a<\/strong>\u9501\u88ab\u91ca\u653e\u4e4b\u540e\uff0c\u540e\u7533\u8bf7\u7684\u7ebf\u7a0b\u53ef\u80fd\u4f1a\u5148\u83b7\u53d6\u5230\u9501\uff0c\u662f\u968f\u673a\u6216\u8005\u6309\u7167\u5176\u4ed6\u4f18\u5148\u7ea7\u6392\u5e8f\u7684\u3002\u6027\u80fd\u66f4\u597d\uff0c\u4f46\u53ef\u80fd\u4f1a\u5bfc\u81f4\u67d0\u4e9b\u7ebf\u7a0b\u6c38\u8fdc\u65e0\u6cd5\u83b7\u53d6\u5230\u9501\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"synchronized_%E5%92%8C_ReentrantLock_%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\"><\/span>synchronized \u548c ReentrantLock \u6709\u4ec0\u4e48\u533a\u522b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h4><span class=\"ez-toc-section\" id=\"%E4%B8%A4%E8%80%85%E9%83%BD%E6%98%AF%E5%8F%AF%E9%87%8D%E5%85%A5%E9%94%81\"><\/span>\u4e24\u8005\u90fd\u662f\u53ef\u91cd\u5165\u9501<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>\u53ef\u91cd\u5165\u9501 \u4e5f\u53eb\u9012\u5f52\u9501\uff0c\u6307\u7684\u662f\u7ebf\u7a0b\u53ef\u4ee5\u518d\u6b21\u83b7\u53d6\u81ea\u5df1\u7684\u5185\u90e8\u9501\u3002\u6bd4\u5982\u4e00\u4e2a\u7ebf\u7a0b\u83b7\u5f97\u4e86\u67d0\u4e2a\u5bf9\u8c61\u7684\u9501\uff0c\u6b64\u65f6\u8fd9\u4e2a\u5bf9\u8c61\u9501\u8fd8\u6ca1\u6709\u91ca\u653e\uff0c\u5f53\u5176\u518d\u6b21\u60f3\u8981\u83b7\u53d6\u8fd9\u4e2a\u5bf9\u8c61\u7684\u9501\u7684\u65f6\u5019\u8fd8\u662f\u53ef\u4ee5\u83b7\u53d6\u7684\uff0c\u5982\u679c\u662f\u4e0d\u53ef\u91cd\u5165\u9501\u7684\u8bdd\uff0c\u5c31\u4f1a\u9020\u6210\u6b7b\u9501\u3002<\/p>\n<p>JDK \u63d0\u4f9b\u7684\u6240\u6709\u73b0\u6210\u7684 Lock \u5b9e\u73b0\u7c7b\uff0c\u5305\u62ec synchronized \u5173\u952e\u5b57\u9501\u90fd\u662f\u53ef\u91cd\u5165\u7684\u3002<\/p>\n<p>\u5728\u4e0b\u9762\u7684\u4ee3\u7801\u4e2d\uff0cmethod1() \u548c method2()\u90fd\u88ab synchronized \u5173\u952e\u5b57\u4fee\u9970\uff0cmethod1()\u8c03\u7528\u4e86method2()\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class SynchronizedDemo {\n    public synchronized void method1() {\n        System.out.println(&quot;\u65b9\u6cd51&quot;);\n        method2();\n    }\n\n    public synchronized void method2() {\n        System.out.println(&quot;\u65b9\u6cd52&quot;);\n    }\n}<\/code><\/pre>\n<p>\u7531\u4e8e synchronized\u9501\u662f\u53ef\u91cd\u5165\u7684\uff0c\u540c\u4e00\u4e2a\u7ebf\u7a0b\u5728\u8c03\u7528method1() \u65f6\u53ef\u4ee5\u76f4\u63a5\u83b7\u5f97\u5f53\u524d\u5bf9\u8c61\u7684\u9501\uff0c\u6267\u884c method2() \u7684\u65f6\u5019\u53ef\u4ee5\u518d\u6b21\u83b7\u53d6\u8fd9\u4e2a\u5bf9\u8c61\u7684\u9501\uff0c\u4e0d\u4f1a\u4ea7\u751f\u6b7b\u9501\u95ee\u9898\u3002\u5047\u5982synchronized\u662f\u4e0d\u53ef\u91cd\u5165\u9501\u7684\u8bdd\uff0c\u7531\u4e8e\u8be5\u5bf9\u8c61\u7684\u9501\u5df2\u88ab\u5f53\u524d\u7ebf\u7a0b\u6240\u6301\u6709\u4e14\u65e0\u6cd5\u91ca\u653e\uff0c\u8fd9\u5c31\u5bfc\u81f4\u7ebf\u7a0b\u5728\u6267\u884c method2()\u65f6\u83b7\u53d6\u9501\u5931\u8d25\uff0c\u4f1a\u51fa\u73b0\u6b7b\u9501\u95ee\u9898<\/p>\n<h4><span class=\"ez-toc-section\" id=\"synchronized_%E4%BE%9D%E8%B5%96%E4%BA%8E_JVM_%E8%80%8C_ReentrantLock_%E4%BE%9D%E8%B5%96%E4%BA%8E_API\"><\/span>synchronized \u4f9d\u8d56\u4e8e JVM \u800c ReentrantLock \u4f9d\u8d56\u4e8e API<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>synchronized \u662f\u4f9d\u8d56\u4e8e JVM \u5b9e\u73b0\u7684\uff0c\u524d\u9762\u6211\u4eec\u4e5f\u8bb2\u5230\u4e86 \u865a\u62df\u673a\u56e2\u961f\u5728 JDK1.6 \u4e3a synchronized \u5173\u952e\u5b57\u8fdb\u884c\u4e86\u5f88\u591a\u4f18\u5316\uff0c\u4f46\u662f\u8fd9\u4e9b\u4f18\u5316\u90fd\u662f\u5728\u865a\u62df\u673a\u5c42\u9762\u5b9e\u73b0\u7684\uff0c\u5e76\u6ca1\u6709\u76f4\u63a5\u66b4\u9732\u7ed9\u6211\u4eec\u3002<\/p>\n<p>ReentrantLock \u662f JDK \u5c42\u9762\u5b9e\u73b0\u7684\uff08\u4e5f\u5c31\u662f API \u5c42\u9762\uff0c\u9700\u8981 lock() \u548c unlock() \u65b9\u6cd5\u914d\u5408 try\/finally \u8bed\u53e5\u5757\u6765\u5b8c\u6210\uff09\uff0c\u6240\u4ee5\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u67e5\u770b\u5b83\u7684\u6e90\u4ee3\u7801\uff0c\u6765\u770b\u5b83\u662f\u5982\u4f55\u5b9e\u73b0\u7684\u3002<\/p>\n<h4><span class=\"ez-toc-section\" id=\"ReentrantLock_%E6%AF%94_synchronized_%E5%A2%9E%E5%8A%A0%E4%BA%86%E4%B8%80%E4%BA%9B%E9%AB%98%E7%BA%A7%E5%8A%9F%E8%83%BD\"><\/span>ReentrantLock \u6bd4 synchronized \u589e\u52a0\u4e86\u4e00\u4e9b\u9ad8\u7ea7\u529f\u80fd<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>\u76f8\u6bd4synchronized\uff0cReentrantLock\u589e\u52a0\u4e86\u4e00\u4e9b\u9ad8\u7ea7\u529f\u80fd\u3002\u4e3b\u8981\u6765\u8bf4\u4e3b\u8981\u6709\u4e09\u70b9\uff1a<br \/>\n<strong>\u7b49\u5f85\u53ef\u4e2d\u65ad :<\/strong> ReentrantLock\u63d0\u4f9b\u4e86\u4e00\u79cd\u80fd\u591f\u4e2d\u65ad\u7b49\u5f85\u9501\u7684\u7ebf\u7a0b\u7684\u673a\u5236\uff0c\u901a\u8fc7 lock.lockInterruptibly() \u6765\u5b9e\u73b0\u8fd9\u4e2a\u673a\u5236\u3002\u4e5f\u5c31\u662f\u8bf4\u5f53\u524d\u7ebf\u7a0b\u5728\u7b49\u5f85\u83b7\u53d6\u9501\u7684\u8fc7\u7a0b\u4e2d\uff0c\u5982\u679c\u5176\u4ed6\u7ebf\u7a0b\u4e2d\u65ad\u5f53\u524d\u7ebf\u7a0b\u300c interrupt() \u300d\uff0c\u5f53\u524d\u7ebf\u7a0b\u5c31\u4f1a\u629b\u51fa InterruptedException \u5f02\u5e38\uff0c\u53ef\u4ee5\u6355\u6349\u8be5\u5f02\u5e38\u8fdb\u884c\u76f8\u5e94\u5904\u7406\u3002<\/p>\n<p><strong>\u53ef\u5b9e\u73b0\u516c\u5e73\u9501 <\/strong>: ReentrantLock\u53ef\u4ee5\u6307\u5b9a\u662f\u516c\u5e73\u9501\u8fd8\u662f\u975e\u516c\u5e73\u9501\u3002\u800csynchronized\u53ea\u80fd\u662f\u975e\u516c\u5e73\u9501\u3002\u6240\u8c13\u7684\u516c\u5e73\u9501\u5c31\u662f\u5148\u7b49\u5f85\u7684\u7ebf\u7a0b\u5148\u83b7\u5f97\u9501\u3002ReentrantLock\u9ed8\u8ba4\u60c5\u51b5\u662f\u975e\u516c\u5e73\u7684\uff0c\u53ef\u4ee5\u901a\u8fc7 ReentrantLock\u7c7b\u7684ReentrantLock(boolean fair)\u6784\u9020\u65b9\u6cd5\u6765\u6307\u5b9a\u662f\u5426\u662f\u516c\u5e73\u7684\u3002<\/p>\n<p><strong>\u53ef\u5b9e\u73b0\u9009\u62e9\u6027\u901a\u77e5\uff08\u9501\u53ef\u4ee5\u7ed1\u5b9a\u591a\u4e2a\u6761\u4ef6\uff09<\/strong>: synchronized\u5173\u952e\u5b57\u4e0ewait()\u548cnotify()\/notifyAll()\u65b9\u6cd5\u76f8\u7ed3\u5408\u53ef\u4ee5\u5b9e\u73b0\u7b49\u5f85\/\u901a\u77e5\u673a\u5236\u3002ReentrantLock\u7c7b\u5f53\u7136\u4e5f\u53ef\u4ee5\u5b9e\u73b0\uff0c\u4f46\u662f\u9700\u8981\u501f\u52a9\u4e8eCondition\u63a5\u53e3\u4e0enewCondition()\u65b9\u6cd5\u3002<\/p>\n<p><strong>\u652f\u6301\u8d85\u65f6<\/strong> \uff1aReentrantLock \u63d0\u4f9b\u4e86 tryLock(timeout) \u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u6307\u5b9a\u7b49\u5f85\u83b7\u53d6\u9501\u7684\u6700\u957f\u7b49\u5f85\u65f6\u95f4\uff0c\u5982\u679c\u8d85\u8fc7\u4e86\u7b49\u5f85\u65f6\u95f4\uff0c\u5c31\u4f1a\u83b7\u53d6\u9501\u5931\u8d25\uff0c\u4e0d\u4f1a\u4e00\u76f4\u7b49\u5f85\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395802897.png\" alt=\"file\" \/><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752395826178.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"ReentrantReadWriteLock_%E9%80%82%E5%90%88%E4%BB%80%E4%B9%88%E5%9C%BA%E6%99%AF%EF%BC%9F\"><\/span>ReentrantReadWriteLock \u9002\u5408\u4ec0\u4e48\u573a\u666f\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u7531\u4e8e ReentrantReadWriteLock \u65e2\u53ef\u4ee5\u4fdd\u8bc1\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u8bfb\u7684\u6548\u7387\uff0c\u540c\u65f6\u53c8\u53ef\u4ee5\u4fdd\u8bc1\u6709\u5199\u5165\u64cd\u4f5c\u65f6\u7684\u7ebf\u7a0b\u5b89\u5168\u3002\u56e0\u6b64\uff0c\u5728\u8bfb\u591a\u5199\u5c11\u7684\u60c5\u51b5\u4e0b\uff0c\u4f7f\u7528 ReentrantReadWriteLock \u80fd\u591f\u660e\u663e\u63d0\u5347\u7cfb\u7edf\u6027\u80fd<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%85%B1%E4%BA%AB%E9%94%81%E5%92%8C%E7%8B%AC%E5%8D%A0%E9%94%81%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\"><\/span>\u5171\u4eab\u9501\u548c\u72ec\u5360\u9501\u6709\u4ec0\u4e48\u533a\u522b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u5171\u4eab\u9501<\/strong>\uff1a\u4e00\u628a\u9501\u53ef\u4ee5\u88ab\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u83b7\u5f97\u3002<br \/>\n<strong>\u72ec\u5360\u9501<\/strong>\uff1a\u4e00\u628a\u9501\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u83b7\u5f97\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E7%BA%BF%E7%A8%8B%E6%8C%81%E6%9C%89%E8%AF%BB%E9%94%81%E8%BF%98%E8%83%BD%E8%8E%B7%E5%8F%96%E5%86%99%E9%94%81%E5%90%97%EF%BC%9F\"><\/span>\u7ebf\u7a0b\u6301\u6709\u8bfb\u9501\u8fd8\u80fd\u83b7\u53d6\u5199\u9501\u5417\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5728\u7ebf\u7a0b\u6301\u6709\u8bfb\u9501\u7684\u60c5\u51b5\u4e0b\uff0c\u8be5\u7ebf\u7a0b\u4e0d\u80fd\u53d6\u5f97\u5199\u9501(\u56e0\u4e3a\u83b7\u53d6\u5199\u9501\u7684\u65f6\u5019\uff0c\u5982\u679c\u53d1\u73b0\u5f53\u524d\u7684\u8bfb\u9501\u88ab\u5360\u7528\uff0c\u5c31\u9a6c\u4e0a\u83b7\u53d6\u5931\u8d25\uff0c\u4e0d\u7ba1\u8bfb\u9501\u662f\u4e0d\u662f\u88ab\u5f53\u524d\u7ebf\u7a0b\u6301\u6709)\u3002<br \/>\n\u5728\u7ebf\u7a0b\u6301\u6709\u5199\u9501\u7684\u60c5\u51b5\u4e0b\uff0c\u8be5\u7ebf\u7a0b\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6\u8bfb\u9501\uff08\u83b7\u53d6\u8bfb\u9501\u65f6\u5982\u679c\u53d1\u73b0\u5199\u9501\u88ab\u5360\u7528\uff0c\u53ea\u6709\u5199\u9501\u6ca1\u6709\u88ab\u5f53\u524d\u7ebf\u7a0b\u5360\u7528\u7684\u60c5\u51b5\u624d\u4f1a\u83b7\u53d6\u5931\u8d25\uff09\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E8%AF%BB%E9%94%81%E4%B8%BA%E4%BB%80%E4%B9%88%E4%B8%8D%E8%83%BD%E5%8D%87%E7%BA%A7%E4%B8%BA%E5%86%99%E9%94%81%EF%BC%9F\"><\/span>\u8bfb\u9501\u4e3a\u4ec0\u4e48\u4e0d\u80fd\u5347\u7ea7\u4e3a\u5199\u9501\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5199\u9501\u53ef\u4ee5\u964d\u7ea7\u4e3a\u8bfb\u9501\uff0c\u4f46\u662f\u8bfb\u9501\u5374\u4e0d\u80fd\u5347\u7ea7\u4e3a\u5199\u9501\u3002\u8fd9\u662f\u56e0\u4e3a\u8bfb\u9501\u5347\u7ea7\u4e3a\u5199\u9501\u4f1a\u5f15\u8d77\u7ebf\u7a0b\u7684\u4e89\u593a\uff0c\u6bd5\u7adf\u5199\u9501\u5c5e\u4e8e\u662f\u72ec\u5360\u9501\uff0c\u8fd9\u6837\u7684\u8bdd\uff0c\u4f1a\u5f71\u54cd\u6027\u80fd\u3002<br \/>\n\u53e6\u5916\uff0c\u8fd8\u53ef\u80fd\u4f1a\u6709\u6b7b\u9501\u95ee\u9898\u53d1\u751f\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff1a\u5047\u8bbe\u4e24\u4e2a\u7ebf\u7a0b\u7684\u8bfb\u9501\u90fd\u60f3\u5347\u7ea7\u5199\u9501\uff0c\u5219\u9700\u8981\u5bf9\u65b9\u90fd\u91ca\u653e\u81ea\u5df1\u9501\uff0c\u800c\u53cc\u65b9\u90fd\u4e0d\u91ca\u653e\uff0c\u5c31\u4f1a\u4ea7\u751f\u6b7b\u9501\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"StampedLock_%E6%98%AF%E4%BB%80%E4%B9%88%EF%BC%9F\"><\/span>StampedLock \u662f\u4ec0\u4e48\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>StampedLock \u662f JDK 1.8 \u5f15\u5165\u7684\u6027\u80fd\u66f4\u597d\u7684\u8bfb\u5199\u9501\uff0c\u4e0d\u53ef\u91cd\u5165\u4e14\u4e0d\u652f\u6301\u6761\u4ef6\u53d8\u91cf Condition\u3002<\/p>\n<p>\u4e0d\u540c\u4e8e\u4e00\u822c\u7684 Lock \u7c7b\uff0cStampedLock \u5e76\u4e0d\u662f\u76f4\u63a5\u5b9e\u73b0 Lock\u6216 ReadWriteLock\u63a5\u53e3\uff0c\u800c\u662f\u57fa\u4e8e CLH \u9501 \u72ec\u7acb\u5b9e\u73b0\u7684\uff08AQS \u4e5f\u662f\u57fa\u4e8e\u8fd9\u73a9\u610f\uff09\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">public class StampedLock implements java.io.Serializable {\n}<\/code><\/pre>\n<p>StampedLock \u63d0\u4f9b\u4e86\u4e09\u79cd\u6a21\u5f0f\u7684\u8bfb\u5199\u63a7\u5236\u6a21\u5f0f\uff1a\u8bfb\u9501\u3001\u5199\u9501\u548c\u4e50\u89c2\u8bfb\u3002<br \/>\n<strong>\u5199\u9501<\/strong>\uff1a\u72ec\u5360\u9501\uff0c\u4e00\u628a\u9501\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u83b7\u5f97\u3002\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u83b7\u53d6\u5199\u9501\u540e\uff0c\u5176\u4ed6\u8bf7\u6c42\u8bfb\u9501\u548c\u5199\u9501\u7684\u7ebf\u7a0b\u5fc5\u987b\u7b49\u5f85\u3002\u7c7b\u4f3c\u4e8e ReentrantReadWriteLock \u7684\u5199\u9501\uff0c\u4e0d\u8fc7\u8fd9\u91cc\u7684\u5199\u9501\u662f\u4e0d\u53ef\u91cd\u5165\u7684\u3002<\/p>\n<p><strong>\u8bfb\u9501 <\/strong>\uff08\u60b2\u89c2\u8bfb\uff09\uff1a\u5171\u4eab\u9501\uff0c\u6ca1\u6709\u7ebf\u7a0b\u83b7\u53d6\u5199\u9501\u7684\u60c5\u51b5\u4e0b\uff0c\u591a\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u540c\u65f6\u6301\u6709\u8bfb\u9501\u3002\u5982\u679c\u5df1\u7ecf\u6709\u7ebf\u7a0b\u6301\u6709\u5199\u9501\uff0c\u5219\u5176\u4ed6\u7ebf\u7a0b\u8bf7\u6c42\u83b7\u53d6\u8be5\u8bfb\u9501\u4f1a\u88ab\u963b\u585e\u3002\u7c7b\u4f3c\u4e8e ReentrantReadWriteLock \u7684\u8bfb\u9501\uff0c\u4e0d\u8fc7\u8fd9\u91cc\u7684\u8bfb\u9501\u662f\u4e0d\u53ef\u91cd\u5165\u7684\u3002<\/p>\n<p><strong>\u4e50\u89c2\u8bfb<\/strong>\uff1a\u5141\u8bb8\u591a\u4e2a\u7ebf\u7a0b\u83b7\u53d6\u4e50\u89c2\u8bfb\u4ee5\u53ca\u8bfb\u9501\u3002\u540c\u65f6\u5141\u8bb8\u4e00\u4e2a\u5199\u7ebf\u7a0b\u83b7\u53d6\u5199\u9501\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4ec0\u4e48\u662f\u7ebf\u7a0b\u548c\u8fdb\u7a0b? \u4f55\u4e3a\u8fdb\u7a0b? \u8fdb\u7a0b\u662f\u7a0b\u5e8f\u7684\u4e00\u6b21\u6267\u884c\u8fc7\u7a0b\uff0c\u662f\u7cfb\u7edf\u8fd0\u884c\u7a0b\u5e8f\u7684\u57fa\u672c\u5355\u4f4d\uff0c\u56e0\u6b64\u8fdb\u7a0b\u662f\u52a8\u6001\u7684\u3002\u7cfb\u7edf\u8fd0\u884c\u4e00\u4e2a\u7a0b\u5e8f\u5373\u662f\u4e00\u4e2a\u8fdb\u7a0b\u4ece\u521b\u5efa\uff0c\u8fd0\u884c\u5230\u6d88\u4ea1\u7684\u8fc7\u7a0b\u3002 \u5728 Java \u4e2d\uff0c\u5f53\u6211\u4eec\u542f\u52a8 main \u51fd\u6570\u65f6\u5176\u5b9e\u5c31\u662f\u542f\u52a8\u4e86\u4e00\u4e2a JVM \u7684\u8fdb\u7a0b\uff0c\u800c main \u51fd\u6570\u6240\u5728\u7684\u7ebf\u7a0b\u5c31\u662f\u8fd9\u4e2a\u8fdb\u7a0b\u4e2d\u7684\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u4e5f\u79f0\u4e3b\u7ebf\u7a0b\u3002 \u5982\u4e0b\u56fe\u6240\u793a\uff0c\u5728 Windows \u4e2d\u901a\u8fc7\u67e5\u770b\u4efb\u52a1\u7ba1\u7406\u5668\u7684\u65b9\u5f0f\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u6e05\u695a\u770b\u5230 Window [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":177,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-158","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts\/158","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/comments?post=158"}],"version-history":[{"count":1,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts\/158\/revisions"}],"predecessor-version":[{"id":178,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts\/158\/revisions\/178"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/media\/177"}],"wp:attachment":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/media?parent=158"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/categories?post=158"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/tags?post=158"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}