{"id":10006534,"date":"2022-09-19T15:14:53","date_gmt":"2022-09-19T07:14:53","guid":{"rendered":"https:\/\/ityet.com\/?p=10006534"},"modified":"2022-09-19T15:14:53","modified_gmt":"2022-09-19T07:14:53","slug":"%e9%ab%98%e6%80%a7%e8%83%bd-java-%e8%ae%a1%e7%ae%97%e6%9c%8d%e5%8a%a1%e7%9a%84%e6%80%a7%e8%83%bd%e8%b0%83%e4%bc%98%e5%ae%9e%e6%88%98","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10006534","title":{"rendered":"\u9ad8\u6027\u80fd Java \u8ba1\u7b97\u670d\u52a1\u7684\u6027\u80fd\u8c03\u4f18\u5b9e\u6218"},"content":{"rendered":"<blockquote><p>\u4f5c\u8005\uff1avivo \u4e92\u8054\u7f51\u670d\u52a1\u5668\u56e2\u961f- Chen Dongxing\u3001Li Haoxuan\u3001Chen Jinxia<\/p><\/blockquote>\n<p>\u968f\u7740\u4e1a\u52a1\u7684\u65e5\u6e10\u590d\u6742\uff0c\u6027\u80fd\u4f18\u5316\u4fe8\u7136\u6210\u4e3a\u4e86\u6bcf\u4e00\u4f4d\u6280\u672f\u4eba\u7684\u5fc5\u4fee\u8bfe\u3002\u6027\u80fd\u4f18\u5316\u4ece\u4f55\u7740\u624b\uff1f\u5982\u4f55\u4ece\u95ee\u9898\u8868\u8c61\u5b9a\u4f4d\u5230\u6027\u80fd\u74f6\u9888\uff1f\u5982\u4f55\u9a8c\u8bc1\u4f18\u5316\u63aa\u65bd\u662f\u5426\u6709\u6548\uff1f\u672c\u6587\u5c06\u4ecb\u7ecd\u5206\u4eab vivo push \u63a8\u8350\u9879\u76ee\u4e2d\u7684\u6027\u80fd\u8c03\u4f18\u5b9e\u8df5\uff0c\u5e0c\u671b\u7ed9\u5927\u5bb6\u63d0\u4f9b\u4e00\u4e9b\u501f\u9274\u548c\u53c2\u8003\u3002<\/p>\n<h2>\u4e00\u3001\u80cc\u666f\u4ecb\u7ecd<\/h2>\n<p>\u5728 Push \u63a8\u8350\u4e2d\uff0c\u7ebf\u4e0a\u670d\u52a1\u4ece Kafka \u63a5\u6536\u9700\u8981\u89e6\u8fbe\u7528\u6237\u7684\u4e8b\u4ef6\uff0c\u4e4b\u540e\u4e3a\u8fd9\u4e9b\u76ee\u6807\u7528\u6237\u9009\u51fa\u6700\u5408\u9002\u7684\u6587\u7ae0\u8fdb\u884c\u63a8\u9001\u3002\u670d\u52a1\u7531 Java \u5f00\u53d1\uff0cCPU \u5bc6\u96c6\u8ba1\u7b97\u578b\u3002<\/p>\n<p>\u968f\u7740\u4e1a\u52a1\u7684\u4e0d\u65ad\u53d1\u5c55\uff0c\u8bf7\u6c42\u5e76\u53d1\u53ca\u6a21\u578b\u8ba1\u7b97\u91cf\u8d8a\u6765\u8d8a\u5927\uff0c\u5bfc\u81f4\u5de5\u7a0b\u4e0a\u9047\u5230\u4e86\u6027\u80fd\u74f6\u9888\uff0cKafka \u6d88\u8d39\u51fa\u73b0\u4e25\u91cd\u7684\u79ef\u538b\u73b0\u8c61\uff0c\u65e0\u6cd5\u53ca\u65f6\u5b8c\u6210\u76ee\u6807\u7528\u6237\u7684\u5206\u53d1\uff0c\u4e1a\u52a1\u589e\u957f\u8bc9\u6c42\u5f97\u4e0d\u5230\u6ee1\u8db3\uff0c\u6545\u4e9f\u9700\u8fdb\u884c\u6027\u80fd\u4e13\u9879\u4f18\u5316\u3002<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508323\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<h2>\u4e8c\u3001\u4f18\u5316\u8861\u91cf\u6307\u6807\u548c\u601d\u8def<\/h2>\n<p>\u6211\u4eec\u7684\u6027\u80fd\u8861\u91cf\u6307\u6807\u662f\u541e\u5410\u91cf TPS \uff0c\u7531\u7ecf\u5178\u516c\u5f0f TPS = \u5e76\u53d1\u6570 \/ \u5e73\u5747\u54cd\u5e94\u65f6\u95f4RT \u53ef\u4ee5\u77e5\u9053\uff0c\u82e5\u9700\u63d0\u9ad8 TPS\uff0c\u53ef\u4ee5\u6709 2 \u79cd\u65b9\u5f0f\uff1a<\/p>\n<ul>\n<li><strong>\u63d0\u9ad8\u5e76\u53d1\u6570<\/strong>\uff0c\u6bd4\u5982\u63d0\u5347\u5355\u673a\u7684\u5e76\u884c\u7ebf\u7a0b\u6570\uff0c\u6216\u8005\u6a2a\u5411\u6269\u5bb9\u673a\u5668\u6570\uff1b<\/li>\n<li><strong>\u964d\u4f4e\u5e73\u5747\u54cd\u5e94\u65f6\u95f4 RT<\/strong>\uff0c\u5305\u62ec\u5e94\u7528\u7ebf\u7a0b\uff08\u4e1a\u52a1\u903b\u8f91\uff09\u6267\u884c\u65f6\u95f4\uff0c\u4ee5\u53ca JVM \u672c\u8eab\u7684 GC \u8017\u65f6\u3002<\/li>\n<\/ul>\n<p>\u5b9e\u9645\u60c5\u51b5\u4e2d\uff0c\u6211\u4eec\u7684\u673a\u5668 CPU \u5229\u7528\u7387\u5df2\u7ecf\u5f88\u9ad8\uff0c\u8fbe\u5230 80% \u4ee5\u4e0a\uff0c\u63d0\u5347\u5355\u673a\u5e76\u53d1\u6570\u7684\u9884\u671f\u6536\u76ca\u6709\u9650\uff0c\u6545\u628a\u4e3b\u8981\u7cbe\u529b\u6295\u5165\u5230\u964d\u4f4e RT \u4e0a\u3002<\/p>\n<p>\u4e0b\u9762\u5c06\u4ece \u70ed\u70b9\u4ee3\u7801 \u548c JVM GC \u4e24\u4e2a\u65b9\u9762\u8fdb\u884c\u8be6\u89e3\uff0c\u6211\u4eec\u5982\u4f55\u5206\u6790\u5b9a\u4f4d\u5230\u6027\u80fd\u74f6\u9888\u70b9\uff0c\u5e76\u4f7f\u7528 3 \u62db\u5c06\u541e\u5410\u91cf\u63d0\u5347 100% \u3002<\/p>\n<h2>\u4e09\u3001\u70ed\u70b9\u4ee3\u7801\u4f18\u5316\u7bc7<\/h2>\n<p>\u5982\u4f55\u5feb\u901f\u627e\u5230\u5e94\u7528\u4e2d\u6700\u8017\u65f6\u7684\u70ed\u70b9\u4ee3\u7801\u5462\uff1f\u501f\u52a9\u963f\u91cc\u5df4\u5df4\u5f00\u6e90\u7684 arthas \u5de5\u5177\uff0c\u6211\u4eec\u83b7\u53d6\u5230\u7ebf\u4e0a\u670d\u52a1\u7684 CPU \u706b\u7130\u56fe\u3002<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508324\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<blockquote><p>\u706b\u7130\u56fe\u8bf4\u660e\uff1a\u706b\u7130\u56fe\u662f\u57fa\u4e8e perf \u7ed3\u679c\u4ea7\u751f\u7684 SVG \u56fe\u7247\uff0c\u7528\u6765\u5c55\u793a CPU \u7684\u8c03\u7528\u6808\u3002<\/p><\/blockquote>\n<p>y \u8f74\u8868\u793a\u8c03\u7528\u6808\uff0c\u6bcf\u4e00\u5c42\u90fd\u662f\u4e00\u4e2a\u51fd\u6570\u3002\u8c03\u7528\u6808\u8d8a\u6df1\uff0c\u706b\u7130\u5c31\u8d8a\u9ad8\uff0c\u9876\u90e8\u5c31\u662f\u6b63\u5728\u6267\u884c\u7684\u51fd\u6570\uff0c\u4e0b\u65b9\u90fd\u662f\u5b83\u7684\u7236\u51fd\u6570\u3002<\/p>\n<p>x \u8f74\u8868\u793a\u62bd\u6837\u6570\uff0c\u5982\u679c\u4e00\u4e2a\u51fd\u6570\u5728 x \u8f74\u5360\u636e\u7684\u5bbd\u5ea6\u8d8a\u5bbd\uff0c\u5c31\u8868\u793a\u5b83\u88ab\u62bd\u5230\u7684\u6b21\u6570\u591a\uff0c\u5373\u6267\u884c\u7684\u65f6\u95f4\u957f\u3002\u6ce8\u610f\uff0cx \u8f74\u4e0d\u4ee3\u8868\u65f6\u95f4\uff0c\u800c\u662f\u6240\u6709\u7684\u8c03\u7528\u6808\u5408\u5e76\u540e\uff0c\u6309\u5b57\u6bcd\u987a\u5e8f\u6392\u5217\u7684\u3002<\/p>\n<p><strong>\u706b\u7130\u56fe\u5c31\u662f\u770b\u9876\u5c42\u7684\u54ea\u4e2a\u51fd\u6570\u5360\u636e\u7684\u5bbd\u5ea6\u6700\u5927\u3002\u53ea\u8981\u6709\u201c\u5e73\u9876\u201d\uff08plateaus\uff09\uff0c\u5c31\u8868\u793a\u8be5\u51fd\u6570\u53ef\u80fd\u5b58\u5728\u6027\u80fd\u95ee\u9898\u3002<\/strong><\/p>\n<p>\u989c\u8272\u6ca1\u6709\u7279\u6b8a\u542b\u4e49\uff0c\u56e0\u4e3a\u706b\u7130\u56fe\u8868\u793a\u7684\u662f CPU \u7684\u7e41\u5fd9\u7a0b\u5ea6\uff0c\u6240\u4ee5\u4e00\u822c\u9009\u62e9\u6696\u8272\u8c03\u3002<\/p>\n<h3>3.1 \u4f18\u53161\uff1a\u5c3d\u91cf\u907f\u514d\u539f\u751f String.split \u65b9\u6cd5<\/h3>\n<h4>3.1.1 \u6027\u80fd\u74f6\u9888\u5206\u6790<\/h4>\n<p>\u4ece\u706b\u7130\u56fe\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u53d1\u73b0\u4e86\u6709 13% \u7684 CPU \u65f6\u95f4\u82b1\u5728\u4e86 java.lang.String.split \u65b9\u6cd5\u4e0a\u3002<\/p>\n<p>\u719f\u6089\u6027\u80fd\u4f18\u5316\u7684\u540c\u5b66\u4f1a\u77e5\u9053\uff0c\u539f\u751f split \u65b9\u6cd5\u662f\u6027\u80fd\u6740\u624b\uff0c\u6548\u7387\u6bd4\u8f83\u4f4e\uff0c\u9891\u7e41\u8c03\u7528\u65f6\u4f1a\u8017\u8d39\u5927\u91cf\u8d44\u6e90\u3002<\/p>\n<p>\u4e0d\u8fc7\u4e1a\u52a1\u4e0a\u7279\u5f81\u5904\u7406\u65f6\u786e\u5b9e\u9700\u8981\u9891\u7e41\u5730 split\uff0c\u5982\u4f55\u4f18\u5316\u5462\uff1f<\/p>\n<p>\u901a\u8fc7\u5206\u6790 split \u6e90\u7801\uff0c\u4ee5\u53ca\u9879\u76ee\u7684\u4f7f\u7528\u573a\u666f\uff0c\u6211\u4eec\u53d1\u73b0\u4e86 3 \u4e2a\u4f18\u5316\u70b9\uff1a<\/p>\n<blockquote><p>\uff081\uff09\u4e1a\u52a1\u4e2d\u672a\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\uff0c\u800c\u539f\u751f split \u5728\u5904\u7406\u5206\u9694\u7b26\u4e3a 2 \u4e2a\u53ca\u4ee5\u4e0a\u5b57\u7b26\u65f6\uff0c\u9ed8\u8ba4\u6309\u6b63\u5219\u8868\u8fbe\u5f0f\u65b9\u5f0f\u5904\u7406\uff1b\u4f17\u6240\u5468\u77e5\uff0c\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u6548\u7387\u662f\u4f4e\u4e0b\u7684\u3002<\/p><\/blockquote>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508325\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<blockquote><p>\uff082\uff09\u5f53\u5206\u9694\u7b26\u4e3a\u5355\u4e2a\u5b57\u7b26\uff08\u4e14\u4e0d\u4e3a\u6b63\u5219\u8868\u8fbe\u5f0f\u5b57\u7b26\uff09\u65f6\uff0c\u539f\u751f String.split \u8fdb\u884c\u4e86\u6027\u80fd\u4f18\u5316\u5904\u7406\uff0c\u4f46\u4e2d\u95f4\u6709\u4e9b\u5185\u90e8\u8f6c\u6362\u5904\u7406\uff0c\u5728\u6211\u4eec\u7684\u5b9e\u9645\u4e1a\u52a1\u573a\u666f\u4e2d\u53cd\u800c\u662f\u591a\u4f59\u7684\u3001\u6d88\u8017\u6027\u80fd\u7684\u3002<\/p><\/blockquote>\n<p>\u5176<strong>\u5177\u4f53\u5b9e\u73b0<\/strong>\u662f\uff1a\u901a\u8fc7 String.indexOf \u53ca String.substring \u65b9\u6cd5\u6765\u5b9e\u73b0\u5206\u5272\u5904\u7406\uff0c\u5c06\u5206\u5272\u7ed3\u679c\u5b58\u5165 ArrayList \u4e2d\uff0c\u6700\u540e\u5c06 ArrayList \u8f6c\u6362\u4e3a string[] \u8f93\u51fa\u3002\u800c\u6211\u4eec\u4e1a\u52a1\u4e2d\uff0c\u5176\u5b9e\u5f88\u591a\u65f6\u5019\u9700\u8981 list \u578b\u7ed3\u679c\uff0c\u591a\u4e86 2 \u6b21 list \u548c string[] \u7684\u4e92\u8f6c\u3002<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508326\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<blockquote><p>\uff083\uff09\u4e1a\u52a1\u4e2d\u8c03\u7528 split \u6700\u9891\u7e41\u7684\u5730\u65b9\uff0c\u5176\u5b9e\u53ea\u9700\u8981 split \u540e\u7684\u7b2c 1 \u4e2a\u7ed3\u679c\uff1b\u539f\u751f split \u65b9\u6cd5\u6216\u5176\u5b83\u5de5\u5177\u7c7b\u6709\u91cd\u8f7d\u4f18\u5316\u65b9\u6cd5\uff0c\u53ef\u4ee5\u6307\u5b9a limit \u53c2\u6570\uff0c\u6ee1\u8db3 limit \u6570\u91cf\u540e\u53ef\u4ee5\u63d0\u524d\u8fd4\u56de\uff1b\u4f46\u4e1a\u52a1\u4ee3\u7801\u4e2d\uff0c\u4f7f\u7528 str.split(delim)[0] \u65b9\u5f0f\uff0c\u975e\u6027\u80fd\u6700\u4f73\u3002<\/p><\/blockquote>\n<h4>3.1.2 \u4f18\u5316\u65b9\u6848<\/h4>\n<p>\u9488\u5bf9\u4e1a\u52a1\u573a\u666f\uff0c\u6211\u4eec\u81ea\u5b9a\u4e49\u5b9e\u73b0\u4e86\u6027\u80fd\u4f18\u5316\u7248\u7684 split \u5b9e\u73b0\u3002<\/p>\n<pre><code>import java.util.ArrayList;\nimport java.util.List;\nimport org.apache.commons.lang3.StringUtils;\n  \n\/**\n * \u81ea\u5b9a\u4e49split\u5de5\u5177\n *\/\npublic class SplitUtils {\n  \n    \/**\n     * \u81ea\u5b9a\u4e49\u5206\u5272\u51fd\u6570\uff0c\u8fd4\u56de\u7b2c\u4e00\u4e2a\n     *\n     * @param str   \u5f85\u5206\u5272\u7684\u5b57\u7b26\u4e32\n     * @param delim \u5206\u9694\u7b26\n     * @return \u5206\u5272\u540e\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\u4e32\n     *\/\n    public static String splitFirst(final String str, final String delim) {\n        if (null == str || StringUtils.isEmpty(delim)) {\n            return str;\n        }\n  \n        int index = str.indexOf(delim);\n        if (index &lt; 0) {\n            return str;\n        }\n        if (index == 0) {\n            \/\/ \u4e00\u5f00\u59cb\u5c31\u662f\u5206\u9694\u7b26\uff0c\u8fd4\u56de\u7a7a\u4e32\n            return &quot;&quot;;\n        }\n  \n        return str.substring(0, index);\n    }\n  \n    \/**\n     * \u81ea\u5b9a\u4e49\u5206\u5272\u51fd\u6570\uff0c\u8fd4\u56de\u5168\u90e8\n     *\n     * @param str   \u5f85\u5206\u5272\u7684\u5b57\u7b26\u4e32\n     * @param delim \u5206\u9694\u7b26\n     * @return \u5206\u5272\u540e\u7684\u8fd4\u56de\u7ed3\u679c\n     *\/\n    public static List&lt;String&gt; split(String str, final String delim) {\n        if (null == str) {\n            return new ArrayList&lt;&gt;(0);\n        }\n  \n        if (StringUtils.isEmpty(delim)) {\n            List&lt;String&gt; result = new ArrayList&lt;&gt;(1);\n            result.add(str);\n  \n            return result;\n        }\n  \n        final List&lt;String&gt; stringList = new ArrayList&lt;&gt;();\n        while (true) {\n            int index = str.indexOf(delim);\n            if (index &lt; 0) {\n                stringList.add(str);\n                break;\n            }\n            stringList.add(str.substring(0, index));\n            str = str.substring(index + delim.length());\n        }\n        return stringList;\n    }\n  \n}<\/code><\/pre>\n<p>\u76f8\u6bd4\u539f\u751f String.split \uff0c\u4e3b\u8981\u6709\u51e0\u65b9\u9762\u7684\u6539\u52a8\uff1a<\/p>\n<ol>\n<li>\u653e\u5f03\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u652f\u6301\uff0c\u4ec5\u652f\u6301\u6309\u5206\u9694\u7b26\u8fdb\u884c split\uff1b<\/li>\n<li>\u51fa\u53c2\u76f4\u63a5\u8fd4\u56de list\u3002\u5206\u5272\u5904\u7406\u5b9e\u73b0\uff0c\u4e0e\u539f\u751f\u5b9e\u73b0\u4e2d\u9488\u5bf9\u5355\u5b57\u7b26\u7684\u5904\u7406\u7c7b\u4f3c\uff0c\u4f7f\u7528 string.indexOf \u53ca string.substring \u65b9\u6cd5\uff0c\u5206\u5272\u7ed3\u679c\u653e\u5165 list \u4e2d\uff0c\u51fa\u53c2\u76f4\u63a5\u8fd4\u56de list\uff0c\u51cf\u5c11\u6570\u636e\u8f6c\u6362\u5904\u7406\uff1b<\/li>\n<li>\u63d0\u4f9b splitFirst \u65b9\u6cd5\uff0c\u4e1a\u52a1\u573a\u666f\u53ea\u9700\u8981\u5206\u9694\u7b26\u524d\u7b2c\u4e00\u6bb5\u5b57\u7b26\u4e32\u65f6\uff0c\u8fdb\u4e00\u6b65\u63d0\u5347\u6027\u80fd\u3002<\/li>\n<\/ol>\n<h4>3.1.3 \u5fae\u57fa\u51c6\u6d4b\u8bd5<\/h4>\n<p>\u5982\u4f55\u9a8c\u8bc1\u6211\u4eec\u7684\u4f18\u5316\u6548\u679c\u5462\uff1f\u9996\u5148\u9009\u7528 jmh \u4f5c\u4e3a<strong>\u5fae\u57fa\u51c6\u6d4b\u8bd5\u5de5\u5177<\/strong>\uff0c\u5bf9\u7167\u9009\u7528 \u539f\u751f String.split \u4ee5\u53ca apache \u7684 StringUtils.split\u65b9\u6cd5\uff0c\u6d4b\u8bd5\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n<blockquote><p>\u9009\u7528\u5355\u5b57\u7b26\u4f5c\u4e3a\u5206\u9694\u7b26<\/p><\/blockquote>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508327\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u53ef\u4ee5\u770b\u51fa\uff0c\u539f\u751f\u5b9e\u73b0\u4e0eapache\u7684\u5de5\u5177\u7c7b\u6027\u80fd\u5dee\u4e0d\u591a\uff0c\u800c\u81ea\u5b9a\u4e49\u5b9e\u73b0\u6027\u80fd\u63d0\u5347\u4e86\u7ea6 50%\u3002<\/p>\n<blockquote><p>\u9009\u7528\u591a\u5b57\u7b26\u4f5c\u4e3a\u5206\u9694\u7b26<\/p><\/blockquote>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508328\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u5f53\u5206\u9694\u7b26\u4f7f\u7528 2 \u4e2a\u957f\u5ea6\u7684\u5b57\u7b26\u65f6\uff0c\u539f\u59cb\u5b9e\u73b0\u7684\u6027\u80fd\u5927\u5e45\u964d\u4f4e\uff0c\u53ea\u6709\u5355 char \u65f6\u7684 1\/3 \uff1b\u800capache\u7684\u5b9e\u73b0\u4e5f\u964d\u4f4e\u81f3\u539f\u6765\u7684 2\/3 \uff0c\u800c\u81ea\u5b9a\u4e49\u5b9e\u73b0\u4e0e\u539f\u6765\u57fa\u672c\u4fdd\u6301\u4e00\u81f4\u3002<\/p>\n<blockquote><p>\u9009\u7528\u5355\u5b57\u7b26\u4f5c\u4e3a\u5206\u9694\u7b26\uff0c\u53ea\u9700\u8fd4\u56de\u7b2c 1 \u4e2a\u5206\u5272\u7ed3\u679c<\/p><\/blockquote>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508329\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u9009\u7528\u5355\u5b57\u7b26\u4f5c\u4e3a\u5206\u9694\u7b26\uff0c\u5e76\u53ea\u9700\u7b2c 1 \u4e2a\u5206\u5272\u7ed3\u679c\u65f6\uff0c\u81ea\u5b9a\u4e49\u5b9e\u73b0\u7684\u6027\u80fd\u662f\u539f\u751f\u5b9e\u73b0\u7684 2 \u500d\uff0c\u5e76\u662f\u53d6\u539f\u751f\u5b9e\u73b0\u5b8c\u6574\u7ed3\u679c\u7684 5 \u500d\u3002<\/p>\n<h4>3.1.4 \u7aef\u5230\u7aef\u4f18\u5316\u6548\u679c<\/h4>\n<p>\u7ecf\u5fae\u57fa\u51c6\u6d4b\u8bd5\u9a8c\u8bc1\u6536\u76ca\u540e\uff0c\u6211\u4eec\u5c06\u4f18\u5316\u90e8\u7f72\u5230\u5728\u7ebf\u670d\u52a1\u4e2d\uff0c\u9a8c\u8bc1\u7aef\u5230\u7aef\u6574\u4f53\u7684\u6027\u80fd\u6536\u76ca\uff1b<\/p>\n<p>\u91cd\u65b0\u4f7f\u7528arthas\u91c7\u96c6\u706b\u7130\u56fe\uff0csplit \u65b9\u6cd5\u8017\u65f6\u964d\u4f4e\u81f3 <strong>2%<\/strong> \u5de6\u53f3\uff1b\u7aef\u5230\u7aef\u6574\u4f53\u8017\u65f6<strong>\u4e0b\u964d\u4e86 31.77%<\/strong> \uff0c\u541e\u5410\u91cf<strong>\u4e0a\u6da8\u4e86 45.24%<\/strong> \uff0c\u6027\u80fd\u6536\u76ca\u7279\u522b\u660e\u663e\u3002<\/p>\n<h3>3.2 \u4f18\u53162\uff1a\u52a0\u5feb map \u7684\u67e5\u8868\u6548\u7387<\/h3>\n<h4>3.2.1 \u6027\u80fd\u74f6\u9888\u5206\u6790<\/h4>\n<p>\u4ece\u706b\u7130\u56fe\u4e2d\uff0c\u6211\u4eec\u53d1\u73b0 HashMap.getOrDefault \u65b9\u6cd5\u8017\u65f6\u5360\u6bd4\u4e5f\u7279\u522b\u591a\uff0c\u8fbe\u5230\u4e86 20%\uff0c\u4e3b\u8981\u5728\u67e5\u8be2\u6743\u91cd map \u4e0a\uff0c\u8fd9\u662f\u56e0\u4e3a\uff1a<\/p>\n<ol>\n<li>\u4e1a\u52a1\u4e2d\u786e\u5b9e\u9700\u9ad8\u9891\u8c03\u7528\uff0c\u7279\u5f81\u4ea4\u53c9\u5904\u7406\u540e\u6570\u91cf\u81a8\u80c0\uff0c\u5355\u673a\u7684\u8c03\u7528\u5e76\u53d1\u8fbe\u5230\u4e86\u7ea6 1000w ops\/s\u3002<\/li>\n<li>\u6743\u91cd map \u672c\u8eab\u4e5f\u5f88\u5927\uff0c\u5b58\u50a8\u4e86 1000 \u4e07\u591a\u7684 entry\uff0c\u5360\u7528\u4e86\u5f88\u5927\u4e00\u5757\u5185\u5b58\uff1b\u540c\u65f6 hash \u78b0\u649e\u7684\u6982\u7387\u4e5f\u589e\u5927\uff0c\u78b0\u649e\u65f6\u7684\u67e5\u8be2\u6548\u7387\u7531 O(1) \u964d\u4f4e\u6210\u4e86 O(n) \uff08\u94fe\u8868\uff09 \u6216 O(logn) \uff08\u7ea2\u9ed1\u6811\uff09\u3002<\/li>\n<\/ol>\n<p>Hashmap \u672c\u8eab\u662f\u975e\u5e38\u9ad8\u6548\u7684 map \u5b9e\u73b0\uff0c\u8d77\u521d\u6211\u4eec\u5c1d\u8bd5\u4e86\u8c03\u6574\u52a0\u8f7d\u56e0\u5b50 loadFactor \u6216 \u6362\u7528\u5176\u5b83 map \u5b9e\u73b0\uff0c\u5747\u672a\u53d6\u5f97\u660e\u663e\u6536\u76ca\u3002<\/p>\n<p><strong>\u5982\u4f55\u624d\u80fd\u63d0\u5347 get \u65b9\u6cd5\u7684\u6027\u80fd\u5462\uff1f<\/strong><\/p>\n<h4>3.2.2 \u4f18\u5316\u65b9\u6848<\/h4>\n<p>\u5206\u6790\u8fc7\u7a0b\u4e2d\u6211\u4eec\u53d1\u73b0\u67e5\u8be2 map \u7684 key\uff08\u4ea4\u53c9\u5904\u7406\u540e\u7684\u7279\u5f81 key \uff09\u662f\u5b57\u7b26\u4e32\u578b\uff0c\u4e14\u5e73\u5747\u957f\u5ea6\u5728 20 \u4ee5\u4e0a\uff1b\u6211\u4eec\u77e5\u9053 string \u7684 equals \u65b9\u6cd5\u5176\u5b9e\u662f\u904d\u5386\u6bd4\u5bf9 char[] \u4e2d\u7684\u5b57\u7b26\uff0ckey \u8d8a\u957f\u5219\u6bd4\u5bf9\u6548\u7387\u8d8a\u4f4e\u3002<\/p>\n<pre><code>public boolean equals(Object anObject) {\n       if (this == anObject) {\n           return true;\n       }\n       if (anObject instanceof String) {\n           String anotherString = (String)anObject;\n           int n = value.length;\n           if (n == anotherString.value.length) {\n               char v1[] = value;\n               char v2[] = anotherString.value;\n               int i = 0;\n               while (n-- != 0) {\n                   if (v1[i] != v2[i])\n                       return false;\n                   i++;\n               }\n               return true;\n           }\n       }\n       return false;\n   }<\/code><\/pre>\n<p>\u662f\u5426\u53ef\u4ee5\u5c06 key \u7684\u957f\u5ea6\u7f29\u77ed\uff0c\u6216\u8005\u751a\u81f3\u6362\u6210\u6570\u503c\u578b\uff1f\u901a\u8fc7\u7b80\u5355\u7684\u5fae\u57fa\u51c6\u6d4b\u8bd5\uff0c\u6211\u4eec\u53d1\u73b0\u601d\u8def\u5e94\u8be5\u662f\u53ef\u884c\u7684\u3002<\/p>\n<p>\u4e8e\u662f\u4e0e\u7b97\u6cd5\u540c\u5b66\u6c9f\u901a\uff0c\u5de7\u7684\u662f\u7b97\u6cd5\u540c\u5b66\u6b63\u597d\u4e5f\u6709\u76f8\u540c\u8bc9\u6c42\uff0c\u4ed6\u4eec\u5728\u5207\u6362\u65b0\u8bad\u7ec3\u6846\u67b6\u8fc7\u7a0b\u4e2d\u53d1\u73b0 string \u7684\u6548\u7387\u7279\u522b\u4f4e\uff0c\u9700\u8981\u628a\u7279\u5f81\u6362\u6210\u6570\u503c\u578b\u3002<\/p>\n<p>\u4e00\u62cd\u5373\u5408\uff0c\u65b9\u6848\u5f88\u5feb\u786e\u5b9a\uff1a<\/p>\n<ol>\n<li>\u7b97\u6cd5\u540c\u5b66\u5c06\u7279\u5f81 key \u6620\u5c04\u6210 long \u578b\u6570\u503c\uff0c\u6620\u5c04\u65b9\u6cd5\u4e3a\u81ea\u5b9a\u4e49\u7684 hash \u5b9e\u73b0\uff0c\u5c3d\u91cf\u51cf\u5c11 hash \u78b0\u649e\u6982\u7387\uff1b<\/li>\n<li>\u7b97\u6cd5\u540c\u5b66\u8bad\u7ec3\u8f93\u51fa\u65b0\u6a21\u578b\u7684\u6743\u91cd map \uff0c\u53ef\u4ee5\u4fdd\u7559\u66f4\u591a entry \uff0c\u4ee5\u6253\u5e73\u57fa\u7ebf\u6a21\u578b\u7684\u6548\u679c\u6307\u6807\uff1b<\/li>\n<li>\u6253\u5e73\u57fa\u7ebf\u6a21\u578b\u7684\u6548\u679c\u6307\u6807\u540e\uff0c\u5728\u7ebf\u670d\u52a1\u7aef\u7070\u5ea6\u65b0\u6a21\u578b\uff0c\u6743\u91cd map \u7684 key \u6539\u7528 long \u578b\uff0c\u9a8c\u8bc1\u6027\u80fd\u6307\u6807\u3002<\/li>\n<\/ol>\n<h4>3.2.3 \u4f18\u5316\u6548\u679c<\/h4>\n<p>\u5728\u589e\u52a0\u4e86 30% \u7684\u7279\u5f81 entry \u6570\u4e0b\uff08\u6a21\u578b\u6548\u679c\u8d85\u8fc7\u57fa\u7ebf\uff09\uff0c\u5de5\u7a0b\u4e0a\u7684\u6027\u80fd\u4e5f\u8fbe\u5230\u4e86\u660e\u663e\u6536\u76ca\uff1b<\/p>\n<p>\u7aef\u5230\u7aef\u6574\u4f53\u8017\u65f6<strong>\u4e0b\u964d\u4e86 20.67%<\/strong>\uff0c\u541e\u5410\u91cf<strong>\u4e0a\u6da8\u4e86 26.09%<\/strong>\uff1b\u6b64\u5916\u5185\u5b58\u4f7f\u7528\u4e0a\u4e5f\u53d6\u5f97\u4e86\u826f\u597d\u6536\u76ca\uff0c\u6743\u91cdmap\u7684\u5185\u5b58\u5927\u5c0f<strong>\u4e0b\u964d\u4e8630%<\/strong>\u3002<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508330\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<h2>\u56db\u3001JVM GC\u4f18\u5316\u7bc7<\/h2>\n<p>Java \u8bbe\u8ba1\u5783\u573e\u81ea\u52a8\u56de\u6536\u7684\u76ee\u7684\u662f\u5c06\u5e94\u7528\u7a0b\u5e8f\u5f00\u53d1\u4eba\u5458\u4ece\u624b\u52a8\u52a8\u6001\u5185\u5b58\u7ba1\u7406\u4e2d\u89e3\u653e\u51fa\u6765\u3002\u5f00\u53d1\u4eba\u5458\u65e0\u9700\u5173\u5fc3\u5185\u5b58\u7684\u5206\u914d\u4e0e\u56de\u6536\uff0c\u4e5f\u4e0d\u7528\u5173\u6ce8\u5206\u914d\u7684\u52a8\u6001\u5185\u5b58\u7684\u751f\u5b58\u671f\u3002\u8fd9\u5b8c\u5168\u6d88\u9664\u4e86\u4e00\u4e9b\u4e0e\u5185\u5b58\u7ba1\u7406\u76f8\u5173\u7684\u9519\u8bef\uff0c\u4ee3\u4ef7\u662f\u589e\u52a0\u4e86\u4e00\u4e9b\u8fd0\u884c\u65f6\u5f00\u9500\u3002<\/p>\n<p>\u5728\u5c0f\u578b\u7cfb\u7edf\u4e0a\u5f00\u53d1\u65f6\uff0cGC \u7684\u6027\u80fd\u5f00\u9500\u53ef\u4ee5\u5ffd\u7565\uff0c\u4f46\u6269\u5c55\u5230\u5927\u578b\u7cfb\u7edf\uff08\u5c24\u5176\u662f\u90a3\u4e9b\u5177\u6709\u5927\u91cf\u6570\u636e\u3001\u8bb8\u591a\u7ebf\u7a0b\u548c\u9ad8\u4e8b\u52a1\u7387\u7684\u5e94\u7528\u7a0b\u5e8f\uff09\u65f6\uff0cGC \u7684\u5f00\u9500\u4e0d\u53ef\u5ffd\u89c6\uff0c\u751a\u81f3\u53ef\u80fd\u6210\u4e3a\u91cd\u8981\u7684\u6027\u80fd\u74f6\u9888\u3002<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508331\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u4e0a\u56fe \u6a21\u62df\u4e86\u4e00\u4e2a\u7406\u60f3\u7684\u7cfb\u7edf\uff0c\u9664\u4e86\u5783\u573e\u6536\u96c6\u4e4b\u5916\uff0c\u5b83\u662f\u5b8c\u5168\u53ef\u4f38\u7f29\u7684\u3002\u7ea2\u7ebf\u8868\u793a\u5728\u5355\u5904\u7406\u5668\u7cfb\u7edf\u4e0a\u53ea\u82b1\u8d39 1% \u65f6\u95f4\u8fdb\u884c\u5783\u573e\u6536\u96c6\u7684\u5e94\u7528\u7a0b\u5e8f\u3002\u8fd9\u610f\u5473\u7740\u5728\u62e5\u6709 32 \u4e2a\u5904\u7406\u5668\u7684\u7cfb\u7edf\u4e0a\uff0c\u541e\u5410\u91cf\u635f\u5931\u8d85\u8fc7 20% \u3002\u6d0b\u7ea2\u8272\u7ebf\u663e\u793a\uff0c\u5bf9\u4e8e\u5783\u573e\u6536\u96c6\u65f6\u95f4\u4e3a 10% \u7684\u5e94\u7528\u7a0b\u5e8f(\u5728\u5355\u5904\u7406\u5668\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u5783\u573e\u6536\u96c6\u65f6\u95f4\u4e0d\u7b97\u592a\u957f)\uff0c\u5f53\u6269\u5c55\u5230 32 \u4e2a\u5904\u7406\u5668\u65f6\uff0c\u4f1a\u635f\u5931 75% \u4ee5\u4e0a\u7684\u541e\u5410\u91cf\u3002<\/p>\n<p>\u6545 <strong>JVM GC \u4e5f\u662f\u5f88\u91cd\u8981\u7684\u6027\u80fd\u4f18\u5316\u63aa\u65bd\u3002<\/strong><\/p>\n<p>\u6211\u4eec\u7684\u63a8\u8350\u670d\u52a1\u4f7f\u7528\u9ad8\u914d\u8ba1\u7b97\u8d44\u6e90\uff0864\u6838256G\uff09\uff0cGC\u7684\u5f71\u54cd\u56e0\u7d20\u633a\u53ef\u89c2\uff1b\u901a\u8fc7\u91c7\u96c6\u76d1\u63a7\u5728\u7ebf\u670d\u52a1 GC \u6570\u636e\uff0c\u53d1\u73b0\u6211\u4eec\u7684\u670d\u52a1 GC \u60c5\u51b5\u633a\u7cdf\u7cd5\u7684\uff0c\u6bcf\u5206\u949fYGC\u7d2f\u8ba1\u8017\u65f6\u7ea6 10s\u3002<\/p>\n<p>GC \u5f00\u9500\u4e3a\u4f55\u8fd9\u4e48\u5927\uff0c\u5982\u4f55\u964d\u4f4e GC \u7684\u8017\u65f6\u5462\uff1f<\/p>\n<h3>4.1 \u4f18\u53163\uff1a\u4f7f\u7528\u5806\u5916\u7f13\u5b58\u4ee3\u66ff\u5806\u5185\u7f13\u5b58<\/h3>\n<h4>4.1.1 \u6027\u80fd\u74f6\u9888\u5206\u6790<\/h4>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508332\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u6211\u4eec dump \u4e86\u670d\u52a1\u7684\u5b58\u6d3b\u5806\u5bf9\u8c61\uff0c\u4f7f\u7528 mat \u5de5\u5177\u8fdb\u884c\u5185\u5b58\u5206\u6790\uff0c\u53d1\u73b0\u6709 2 \u4e2a\u5bf9\u8c61\u7279\u522b\u5de8\u5927\uff0c\u5360\u4e86\u603b\u5b58\u6d3b\u5806\u5185\u5b58\u7684 76.8%\u3002\u5176\u4e2d\uff1a<\/p>\n<ul>\n<li>\u7b2c 1 \u5927\u5bf9\u8c61\u662f\u672c\u5730\u7f13\u5b58\uff0c\u5b58\u50a8\u4e86\u7ec6\u7c92\u5ea6\u7ea7\u522b\u7684\u5e38\u7528\u6570\u636e\uff0c\u6bcf\u53f0\u673a\u5668\u5343\u4e07\u7ea7\u522b\u6570\u636e\u91cf\uff1b\u4f7f\u7528 caffine \u7f13\u5b58\u7ec4\u4ef6\uff0c\u7f13\u5b58\u81ea\u52a8\u5237\u65b0\u5468\u671f\u8bbe\u5b9a 1 \u5c0f\u65f6\uff1b\u76ee\u7684\u662f\u5c3d\u91cf\u51cf\u5c11 IO \u67e5\u8be2\u6b21\u6570\uff1b<\/li>\n<li>\u7b2c 2 \u5927\u5bf9\u8c61\u662f\u6a21\u578b\u6743\u91cd map \u672c\u8eab\uff0c\u5e38\u9a7b\u5185\u5b58\u4e2d\uff0c\u4e0d\u4f1a update\uff0c\u7b49\u65b0\u6a21\u578b\u8f7d\u5165\u540e\u88ab\u4f5c\u4e3a\u65e7\u6a21\u578b\u8fdb\u884c\u5378\u8f7d\u3002<\/li>\n<\/ul>\n<h4>4.1.2 \u4f18\u5316\u65b9\u6848<\/h4>\n<p>\u5982\u4f55\u80fd\u5c3d\u91cf\u7f13\u5b58\u8f83\u591a\u7684\u6570\u636e\uff0c\u540c\u65f6\u907f\u514d\u8fc7\u5927\u7684 GC \u538b\u529b\u5462\uff1f<\/p>\n<p>\u6211\u4eec\u60f3\u5230\u4e86\u628a\u7f13\u5b58\u5bf9\u8c61\u79fb\u5230\u5806\u5916\uff0c\u8fd9\u6837\u53ef\u4ee5\u4e0d\u53d7\u5806\u5185\u5185\u5b58\u5927\u5c0f\u7684\u9650\u5236\uff1b\u5e76\u4e14\u5806\u5916\u5185\u5b58\uff0c\u5e76\u4e0d\u53d7 JVM GC \u7684\u7ba1\u63a7\uff0c\u907f\u514d\u4e86\u7f13\u5b58\u8fc7\u5927\u5bf9 GC \u7684\u5f71\u54cd\u3002\u7ecf\u8fc7\u8c03\u7814\uff0c\u6211\u4eec\u51b3\u5b9a\u91c7\u7528\u6210\u719f\u7684\u5f00\u6e90\u5806\u5916\u7f13\u5b58\u7ec4\u4ef6 OHC \u3002<\/p>\n<p><strong>\uff081\uff09OHC \u4ecb\u7ecd<\/strong><\/p>\n<blockquote><p>\u7b80\u4ecb<\/p><\/blockquote>\n<p>OHC \u5168\u79f0\u4e3a off-heap-cache\uff0c\u5373\u5806\u5916\u7f13\u5b58\uff0c\u662f 2015 \u5e74\u9488\u5bf9 Apache Cassandra \u5f00\u53d1\u7684\u7f13\u5b58\u6846\u67b6\uff0c\u540e\u6765\u4ece Cassandra \u9879\u76ee\u4e2d\u72ec\u7acb\u51fa\u6765\uff0c\u6210\u4e3a\u5355\u72ec\u7684\u7c7b\u5e93\uff0c\u5176\u9879\u76ee\u5730\u5740\u4e3a<a href=\"https:\/\/link.segmentfault.com\/?enc=jwvd6tzEx4lb0qSzBjSx7Q%3D%3D.LsI26nprTxrqFldNC0F1MYY0AsV22eO9h6%2Bjvv023xA%3D\" rel=\"nofollow\">https:\/\/github.com\/snazy\/ohc<\/a> \u3002<\/p>\n<blockquote><p>\u7279\u6027<\/p><\/blockquote>\n<ul>\n<li>\u6570\u636e\u5b58\u50a8\u5728\u5806\u5916\uff0c\u53ea\u6709\u5c11\u91cf\u5143\u6570\u636e\u5b58\u50a8\u5806\u5185\uff0c\u4e0d\u5f71\u54cd GC<\/li>\n<li>\u652f\u6301\u4e3a\u6bcf\u4e2a\u7f13\u5b58\u9879\u8bbe\u7f6e\u8fc7\u671f\u65f6\u95f4<\/li>\n<li>\u652f\u6301\u914d\u7f6e LRU\u3001W_TinyLFU \u9a71\u9010\u7b56\u7565<\/li>\n<li>\u80fd\u591f\u7ef4\u62a4\u5927\u91cf\u7684\u7f13\u5b58\u6761\u76ee<\/li>\n<li>\u652f\u6301\u5f02\u6b65\u52a0\u8f7d\u7f13\u5b58<\/li>\n<li>\u8bfb\u5199\u901f\u5ea6\u5728\u5fae\u79d2\u7ea7\u522b<\/li>\n<\/ul>\n<p><strong>\uff082\uff09OHC \u7528\u6cd5<\/strong><\/p>\n<p>\u5feb\u901f\u5f00\u59cb\uff1a<\/p>\n<pre><code>OHCache ohCache = OHCacheBuilder.newBuilder().\n        keySerializer(yourKeySerializer)\n        .valueSerializer(yourValueSerializer)\n        .build();<\/code><\/pre>\n<p>\u53ef\u9009\u914d\u7f6e\u9879\uff1a<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508333\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u5728\u6211\u4eec\u7684\u670d\u52a1\u4e2d\uff0c\u8bbe\u7f6e capacity \u5bb9\u91cf 12G\uff0csegmentCount \u5206\u6bb5\u6570 1024\uff0c\u5e8f\u5217\u5316\u534f\u8bae\u4f7f\u7528 kryo\u3002<\/p>\n<h4>4.1.3 \u4f18\u5316\u6548\u679c<\/h4>\n<p>\u5207\u6362\u5230\u5806\u5916\u7f13\u5b58\u540e\uff0c\u670d\u52a1 YGC \u964d\u4f4e\u5230\u4e86 800ms \/ \u6bcf\u5206\u949f\uff0c\u7aef\u5230\u7aef\u7684\u6574\u4f53\u541e\u5410\u91cf\u4e0a\u6da8\u4e86\u7ea6 20%\u3002<\/p>\n<h3>4.2 \u601d\u8003\u9898<\/h3>\n<p>\u5728Java GC\u4f18\u5316\u4e2d\uff0c\u6211\u4eec\u628a\u672c\u5730\u7f13\u5b58\u5bf9\u8c61\u4eceJava\u5806\u5185\u79fb\u5230\u4e86\u5806\u5916\uff0c\u53d6\u5f97\u4e86\u4e0d\u9519\u7684\u6027\u80fd\u6536\u76ca\u3002 \u8fd8\u8bb0\u5f97\u4e0a\u6587\u63d0\u5230\u7684\u53e6\u4e00\u4e2a\u5de8\u578b\u5bf9\u8c61\uff0c \u6a21\u578b\u6743\u91cd map \u5417 \uff1f\u6a21\u578b\u6743\u91cd map \u80fd\u5426\u4e5f\u4ece Java \u5806\u5185\u79fb\u9664\uff1f<\/p>\n<p>\u7b54\u6848\u662f\u53ef\u4ee5\u7684\u3002\u6211\u4eec\u4f7f\u7528C++\u6539\u5199\u4e86\u6a21\u578b\u63a8\u7406\u8ba1\u7b97\u90e8\u5206\uff0c\u5305\u62ec\u6743\u91cdmap\u7684\u5b58\u50a8\u4e0e\u68c0\u7d22\u3001\u6392\u5e8f\u5f97\u5206\u8ba1\u7b97\u7b49\u903b\u8f91\uff1b\u7136\u540e\u5c06C++\u4ee3\u7801\u8f93\u51fa\u4e3a so \u5e93\u6587\u4ef6\uff0cJava\u7a0b\u5e8f\u901a\u8fc7 <strong>native<\/strong> \u65b9\u5f0f\u8c03\u7528\uff0c\u5b9e\u73b0\u5c06\u6743\u91cdmap\u4ece Jvm \u5806\u5185\u79fb\u51fa\uff0c\u83b7\u5f97\u4e86\u5f88\u597d\u7684\u6027\u80fd\u6536\u76ca\u3002<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000042508334\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<h2>\u4e94\u3001\u7ed3\u675f\u8bed<\/h2>\n<p>\u901a\u8fc7\u4e0a\u6587\u4ecb\u7ecd\u7684 3 \u4e2a\u63aa\u65bd\uff0c\u6211\u4eec\u4ece \u70ed\u70b9\u4ee3\u7801\u4f18\u5316 \u4e0e Jvm GC\u4e24\u65b9\u9762\u6539\u5584\u4e86\u670d\u52a1\u8d1f\u8f7d\u4e0e\u6027\u80fd\uff0c\u6574\u4f53\u541e\u5410\u91cf\u7ffb\u4e86 1 \u500d\uff0c\u8fbe\u5230\u4e86\u9636\u6bb5\u6027\u7684\u9884\u671f\u76ee\u6807\u3002<\/p>\n<p>\u4e0d\u8fc7\u6027\u80fd\u8c03\u4f18\u662f\u6c38\u65e0\u6b62\u5883\u7684\uff0c\u800c\u4e14\u6bcf\u4e2a\u4e1a\u52a1\u573a\u666f\u3001\u6bcf\u4e2a\u7cfb\u7edf\u7684\u5b9e\u9645\u60c5\u51b5\u4e5f\u90fd\u662f\u5343\u5dee\u4e07\u522b\uff0c\u5f88\u96be\u75281\u7bc7\u6587\u7ae0\u53bb\u6db5\u76d6\u4ecb\u7ecd\u6240\u6709\u7684\u4f18\u5316\u573a\u666f\u3002\u5e0c\u671b\u672c\u6587\u4ecb\u7ecd\u7684\u4e00\u4e9b\u8c03\u4f18\u5b9e\u6218\u7ecf\u9a8c\uff0c\u6bd4\u5982\u5982\u4f55\u786e\u5b9a\u4f18\u5316\u65b9\u5411\u3001\u5982\u4f55\u7740\u624b\u5206\u6790\u4ee5\u53ca\u5982\u4f55\u9a8c\u8bc1\u6536\u76ca\uff0c\u80fd\u7ed9\u5927\u5bb6\u4e00\u4e9b\u501f\u9274\u548c\u53c2\u8003\u3002<\/p>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000042508321\">https:\/\/segmentfault.com\/a\/1190000042508321<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4f5c\u8005\uff1avivo \u4e92\u8054\u7f51\u670d\u52a1\u5668\u56e2\u961f- Chen Dongxing\u3001Li Haoxuan\u3001Chen Jinxia  [&hellip;]<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[],"tags":[],"class_list":["post-10006534","post","type-post","status-publish","format-standard","hentry"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10006534","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10006534"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10006534\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10006534"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10006534"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10006534"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}