{"id":4080,"date":"2019-04-03T18:33:18","date_gmt":"2019-04-03T10:33:18","guid":{"rendered":"http:\/\/www.xttblog.com\/?p=4080"},"modified":"2019-04-03T18:33:18","modified_gmt":"2019-04-03T10:33:18","slug":"%e5%96%9c%e6%ac%a2-g1-%e5%9e%83%e5%9c%be%e6%94%b6%e9%9b%86%e5%99%a8%e5%b0%b1%e8%a6%81%e6%94%be%e8%82%86%ef%bc%8c%e7%88%b1%e4%b8%8a-cms-%e5%9e%83%e5%9c%be%e6%94%b6%e9%9b%86%e5%99%a8%e8%a6%81%e5%85%8b","status":"publish","type":"post","link":"https:\/\/www.xttblog.com\/?p=4080","title":{"rendered":"\u559c\u6b22 G1 \u5783\u573e\u6536\u96c6\u5668\u5c31\u8981\u653e\u8086\uff0c\u7231\u4e0a CMS \u5783\u573e\u6536\u96c6\u5668\u8981\u514b\u5236"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728 JDK1.7 \u4e4b\u524d\uff0cCMS \u5783\u573e\u6536\u96c6\u5668\u662f\u4e3b\u6d41\u7684\u9009\u62e9\u3002\u4f46\u81ea\u4ece JDK 6u14 \u4f53\u9a8c\u7248\u672c\u9762\u4e16\uff0c\u5230 JDK 7u4 \u7248\u672c\u53d1\u884c\uff0cG1 \u5783\u573e\u6536\u96c6\u5668\u9010\u6e10\u6210\u4e86\u4e3b\u6d41\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u76ee\u524d\u7684 JDK8 \u4ee5\u540e\u7684\u7248\u672c\uff0cG1 \u5df2\u7ecf\u76f8\u5bf9\u7a33\u5b9a\uff0c\u4e14\u57fa\u672c\u4e0a\u5df2\u7ecf\u53d6\u4ee3\u4e86 CMS\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">G1 GC\uff0c\u5168\u79f0 Garbage-First Garbage Collector\uff0c\u901a\u8fc7-XX:+UseG1GC \u53c2\u6570\u6765\u542f\u7528\u3002G1 \u7684\u4e3b\u8981\u5173\u6ce8\u70b9\u5728\u4e8e\u8fbe\u5230\u53ef\u63a7\u7684\u505c\u987f\u65f6\u95f4\uff0c\u5728\u8fd9\u4e2a\u57fa\u7840\u4e0a\u5c3d\u53ef\u80fd\u63d0\u9ad8\u541e\u5410\u91cf\uff0c\u8fd9\u4e00\u70b9\u975e\u5e38\u91cd\u8981\u3002\u548c CMS \u76f8\u540c\u7684\u5730\u65b9\u5728\u4e8e\uff0c\u5b83\u4eec\u90fd\u5c5e\u4e8e\u5e76\u53d1\u6536\u96c6\u5668\uff0c\u5728\u5927\u90e8\u5206\u7684\u6536\u96c6\u9636\u6bb5\u90fd\u4e0d\u9700\u8981\u6302\u8d77\u5e94\u7528\u7a0b\u5e8f\u3002\u533a\u522b\u5728\u4e8e\uff0cG1 \u6ca1\u6709 CMS \u7684\u788e\u7247\u5316\u95ee\u9898\uff08\u6216\u8005\u8bf4\u4e0d\u90a3\u4e48\u4e25\u91cd\uff09\uff0c\u540c\u65f6\u63d0\u4f9b\u4e86\u66f4\u52a0\u53ef\u63a7\u7684\u505c\u987f\u65f6\u95f4\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b98\u7f51\u5173\u4e8e G1 \u7684\u76f8\u5173\u63cf\u8ff0\u5982\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/wx1.sinaimg.cn\/large\/8fa5dcfcgy1g1pm03ermgj20hu067tag.jpg\" alt=\"\" \/><figcaption>G1 \u5783\u573e\u6536\u96c6\u5668\u5b98\u65b9\u8bf4\u660e<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ffb\u8bd1\u8fc7\u6765\uff0c\u5927\u81f4\u610f\u601d\u662f\u8bf4\uff1aG1 \u5783\u573e\u6536\u96c6\u7b97\u6cd5\u4e3b\u8981\u5e94\u7528\u5728\u591a CPU \u5927\u5185\u5b58\u7684\u670d\u52a1\u4e2d\uff0c\u5728\u6ee1\u8db3\u9ad8\u541e\u5410\u91cf\u7684\u540c\u65f6\uff0c\u7adf\u53ef\u80fd\u7684\u6ee1\u8db3\u5783\u573e\u56de\u6536\u65f6\u7684\u6682\u505c\u65f6\u95f4\uff0c\u8be5\u8bbe\u8ba1\u4e3b\u8981\u9488\u5bf9\u5982\u4e0b\u5e94\u7528\u573a\u666f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u50cf CMS \u6536\u96c6\u5668\u4e00\u6837\uff0c\u80fd\u4e0e\u5e94\u7528\u7a0b\u5e8f\u7ebf\u7a0b\u5e76\u53d1\u6267\u884c\u3002<\/li><li>\u6574\u7406\u7a7a\u95f2\u7a7a\u95f4\u66f4\u5feb<\/li><li>\u9700\u8981 GC \u505c\u987f\u65f6\u95f4\u66f4\u597d\u9884\u6d4b<\/li><li>\u4e0d\u5e0c\u671b\u727a\u7272\u5927\u91cf\u7684\u541e\u5410\u6027\u80fd<\/li><li>\u4e0d\u9700\u8981\u66f4\u5927\u7684 Java Heap<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee5\u5f80\u7684\u5783\u573e\u56de\u6536\u7b97\u6cd5\uff0c\u5982 CMS\uff0c\u5806\u5185\u5b58\u7ed3\u6784\u5927\u6982\u5982\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/wx1.sinaimg.cn\/large\/8fa5dcfcgy1g1pm2ggi6sj20gw03j3yv.jpg\" alt=\"\" \/><figcaption>CMS \u5783\u573e\u6536\u96c6\u5668\u5806\u5185\u5b58\u7ed3\u6784<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u770b\u5230\u8fd9\u4e9b space \u5fc5\u987b\u662f\u5730\u5740\u8fde\u7eed\u7684\u7a7a\u95f4\u3002\u800c\u5728 G1 \u7684\u7b97\u6cd5\u4e2d\uff0c\u91c7\u7528\u4e86\u53e6\u5916\u4e00\u79cd\u5b8c\u5168\u4e0d\u540c\u7684\u65b9\u5f0f\u7ec4\u7ec7\u5806\u5185\u5b58\uff0c\u5806\u5185\u5b58\u88ab\u5212\u5206\u4e3a\u591a\u4e2a\u5927\u5c0f\u76f8\u7b49\u7684\u5185\u5b58\u5757\uff08Region\uff09\uff0c\u6bcf\u4e2a Region \u662f\u903b\u8f91\u8fde\u7eed\u7684\u4e00\u6bb5\u5185\u5b58\uff0c\u7ed3\u6784\u5982\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/wx1.sinaimg.cn\/large\/8fa5dcfcgy1g1pm3nr4tbj20hx09lwfm.jpg\" alt=\"\" \/><figcaption>G1 \u7684\u7b97\u6cd5\u4e2d\u7684 Region<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e0a\u56fe\u4e2d\u7684\u4e00\u4e9b Region \u6807\u660e\u4e86 H\uff0c\u5b83\u4ee3\u8868 Humongous\uff0c\u8fd9\u8868\u793a\u8fd9\u4e9b Region \u5b58\u50a8\u7684\u662f\u5de8\u5927\u5bf9\u8c61\uff08humongous object\uff0cH-obj\uff09\uff0c\u5373\u5927\u5c0f\u5927\u4e8e\u7b49\u4e8e region \u4e00\u534a\u7684\u5bf9\u8c61\u3002H-obj \u6709\u5982\u4e0b\u51e0\u4e2a\u7279\u5f81\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>H-obj \u76f4\u63a5\u5206\u914d\u5230\u4e86 old gen\uff0c\u9632\u6b62\u4e86\u53cd\u590d\u62f7\u8d1d\u79fb\u52a8\u3002<\/li><li>H-obj \u5728 global concurrent marking \u9636\u6bb5\u7684 cleanup \u548c full GC \u9636\u6bb5\u56de\u6536\u3002<\/li><li>\u5728\u5206\u914d H-obj \u4e4b\u524d\u5148\u68c0\u67e5\u662f\u5426\u8d85\u8fc7 initiating heap occupancy percent \u548c the marking threshold, \u5982\u679c\u8d85\u8fc7\u7684\u8bdd\uff0c\u5c31\u542f\u52a8global concurrent marking\uff0c\u4e3a\u7684\u662f\u63d0\u65e9\u56de\u6536\uff0c\u9632\u6b62 evacuation failures \u548c full GC\u3002<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5806\u5185\u5b58\u4e2d\u7684 Region \u5927\u5c0f\u53ef\u4ee5\u901a\u8fc7 -XX:G1HeapRegionSize \u53c2\u6570\u6307\u5b9a\uff0c\u5927\u5c0f\u533a\u95f4\u53ea\u80fd\u662f 1M\u30012M\u30014M\u30018M\u300116M \u548c 32M\uff0c\u603b\u4e4b\u662f 2 \u7684\u5e42\u6b21\u65b9\uff0c\u5982\u679c G1HeapRegionSize \u4e3a\u9ed8\u8ba4\u503c\uff0c\u5219\u5728\u5806\u521d\u59cb\u5316\u65f6\u8ba1\u7b97 Region \u7684\u5b9e\u8df5\u5927\u5c0f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6267\u884c\u5783\u573e\u6536\u96c6\u65f6\uff0c\u548c CMS \u4e00\u6837\uff0cG1 \u6536\u96c6\u7ebf\u7a0b\u5728\u6807\u8bb0\u9636\u6bb5\u548c\u5e94\u7528\u7a0b\u5e8f\u7ebf\u7a0b\u5e76\u53d1\u6267\u884c\uff0c\u6807\u8bb0\u7ed3\u675f\u540e\uff0cG1 \u4e5f\u5c31\u77e5\u9053\u54ea\u4e9b\u533a\u5757\u57fa\u672c\u4e0a\u662f\u5783\u573e\uff0c\u5b58\u6d3b\u5bf9\u8c61\u6781\u5c11\uff0cG1 \u4f1a\u5148\u4ece\u8fd9\u4e9b\u533a\u5757\u4e0b\u624b\uff0c\u56e0\u4e3a\u4ece\u8fd9\u4e9b\u533a\u5757\u80fd\u5f88\u5feb\u91ca\u653e\u5f97\u5230\u5f88\u5927\u7684\u53ef\u7528\u7a7a\u95f4\uff0c\u8fd9\u4e5f\u662f\u4e3a\u4ec0\u4e48 G1 \u88ab\u53d6\u540d\u4e3a Garbage-First \u7684\u539f\u56e0\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">G1 \u4f7f\u7528\u4e86\u505c\u987f\u9884\u6d4b\u6a21\u578b\u6765\u6ee1\u8db3\u7528\u6237\u6307\u5b9a\u7684\u505c\u987f\u65f6\u95f4\u76ee\u6807\uff0c\u5e76\u57fa\u4e8e\u76ee\u6807\u6765\u9009\u62e9\u8fdb\u884c\u5783\u573e\u56de\u6536\u7684\u533a\u5757\u6570\u91cf\u3002G1 \u91c7\u7528\u589e\u91cf\u56de\u6536\u7684\u65b9\u5f0f\uff0c\u6bcf\u6b21\u56de\u6536\u4e00\u4e9b\u533a\u5757\uff0c\u800c\u4e0d\u662f\u6574\u5806\u56de\u6536\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">G1 \u4e0d\u662f\u4e00\u4e2a\u5b9e\u65f6\u6536\u96c6\u5668\uff0c\u5b83\u4f1a\u5c3d\u529b\u6ee1\u8db3\u6211\u4eec\u7684\u505c\u987f\u65f6\u95f4\u8981\u6c42\uff0c\u4f46\u4e5f\u4e0d\u662f\u7edd\u5bf9\u7684\uff0c\u5b83\u57fa\u4e8e\u4e4b\u524d\u5783\u573e\u6536\u96c6\u7684\u6570\u636e\u7edf\u8ba1\uff0c\u4f30\u8ba1\u51fa\u5728\u7528\u6237\u6307\u5b9a\u7684\u505c\u987f\u65f6\u95f4\u5185\u80fd\u6536\u96c6\u591a\u5c11\u4e2a\u533a\u5757\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">G1 \u6709\u548c\u5e94\u7528\u7a0b\u5e8f\u4e00\u8d77\u8fd0\u884c\u7684\u5e76\u53d1\u9636\u6bb5\uff0c\u4e5f\u6709 stop-the-world \u7684\u5e76\u884c\u9636\u6bb5\u3002\u4f46\u662f\uff0cFull GC \u7684\u65f6\u5019\u8fd8\u662f\u5355\u7ebf\u7a0b\u8fd0\u884c\u7684\uff0c\u6240\u4ee5\u6211\u4eec\u5e94\u8be5\u5c3d\u91cf\u907f\u514d\u53d1\u751f Full GC\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">G1 \u4e2d\u6709 3 \u4e2a\u91cd\u8981\u7684\u6570\u636e\u7ed3\u6784\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>SATB\u3002\u5168\u79f0\u662f Snapshot-At-The-Beginning\uff0c\u7531\u5b57\u9762\u7406\u89e3\uff0c\u662f GC \u5f00\u59cb\u65f6\u6d3b\u7740\u7684\u5bf9\u8c61\u7684\u4e00\u4e2a\u5feb\u7167\u3002\u5b83\u662f\u901a\u8fc7 Root Tracing \u5f97\u5230\u7684\uff0c\u4f5c\u7528\u662f\u7ef4\u6301\u5e76\u53d1 GC \u7684\u6b63\u786e\u6027\u3002SATB \u7684\u505a\u6cd5\u7cbe\u5ea6\u6bd4\u8f83\u4f4e\uff0c\u53ef\u80fd\u4f1a\u9020\u6210\u7684 float garbage \u6bd4\u8f83\u591a\u3002<\/li><li>Remembered Sets\uff1a\u6bcf\u4e2a\u533a\u5757\u90fd\u6709\u4e00\u4e2a RSet\uff0c\u7528\u4e8e\u8bb0\u5f55\u8fdb\u5165\u8be5\u533a\u5757\u7684\u5bf9\u8c61\u5f15\u7528\uff08\u5982\u533a\u5757 A \u4e2d\u7684\u5bf9\u8c61\u5f15\u7528\u4e86\u533a\u5757 B\uff0c\u533a\u5757 B \u7684 Rset \u9700\u8981\u8bb0\u5f55\u8fd9\u4e2a\u4fe1\u606f\uff09\uff0c\u5b83\u7528\u4e8e\u5b9e\u73b0\u6536\u96c6\u8fc7\u7a0b\u7684\u5e76\u884c\u5316\u4ee5\u53ca\u4f7f\u5f97\u533a\u5757\u80fd\u8fdb\u884c\u72ec\u7acb\u6536\u96c6\u3002\u603b\u4f53\u4e0a Remembered Sets \u6d88\u8017\u7684\u5185\u5b58\u5c0f\u4e8e 5%\u3002<\/li><li>Collection Sets\uff1a\u5c06\u8981\u88ab\u56de\u6536\u7684\u533a\u5757\u96c6\u5408\u3002GC \u65f6\uff0c\u5728\u8fd9\u4e9b\u533a\u5757\u4e2d\u7684\u5bf9\u8c61\u4f1a\u88ab\u590d\u5236\u5230\u5176\u4ed6\u533a\u5757\u4e2d\uff0c\u603b\u4f53\u4e0a Collection Sets \u6d88\u8017\u7684\u5185\u5b58\u5c0f\u4e8e 1%\u3002<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">G1 \u7684\u8fd0\u884c\u8fc7\u7a0b\u4e3b\u8981\u5305\u542b\u5982\u4e0b 4 \u79cd\u64cd\u4f5c\u65b9\u5f0f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>YGC\uff08\u4e0d\u540c\u4e8eCMS\uff09<br><\/li><li>\u5e76\u53d1\u9636\u6bb5<br><\/li><li>\u6df7\u5408\u6a21\u5f0f<\/li><li>full GC \uff08\u4e00\u822c\u662fG1\u51fa\u73b0\u95ee\u9898\u65f6\u53d1\u751f\uff09<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">YGC\uff0c\u4e5f\u5c31\u662f young gc\u3002<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/wx1.sinaimg.cn\/large\/8fa5dcfcgy1g1pmaueiq2j208w05et97.jpg\" alt=\"\" \/><figcaption>G1 young gc<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0a\u56fe\u4e2d\u6bcf\u4e2a\u5c0f\u533a\u5757\u90fd\u4ee3\u8868 G1 \u7684\u4e00\u4e2a\u533a\u57df\uff08Region\uff09\uff0c\u533a\u5757\u91cc\u9762\u7684\u5b57\u6bcd\u4ee3\u8868\u4e0d\u540c\u7684\u5206\u4ee3\u5185\u5b58\u7a7a\u95f4\u7c7b\u578b\uff08\u5982[E]Eden,[O]Old,[S]Survivor\uff09\u7a7a\u767d\u7684\u533a\u5757\u4e0d\u5c5e\u4e8e\u4efb\u4f55\u4e00\u4e2a\u5206\u533a\uff1bG1 \u53ef\u4ee5\u5728\u9700\u8981\u7684\u65f6\u5019\u4efb\u610f\u6307\u5b9a\u8fd9\u4e2a\u533a\u57df\u5c5e\u4e8e Eden \u6216\u662f O \u533a\u4e4b\u7c7b\u7684\u3002<br> G1 YoungGC \u5728 Eden \u5145\u6ee1\u65f6\u89e6\u53d1\uff0c\u5728\u56de\u6536\u4e4b\u540e\u6240\u6709\u4e4b\u524d\u5c5e\u4e8e Eden \u7684\u533a\u5757\u5168\u53d8\u6210\u7a7a\u767d\u3002\u7136\u540e\u81f3\u5c11\u6709\u4e00\u4e2a\u533a\u5757\u662f\u5c5e\u4e8e S \u533a\u7684\uff08\u5982\u56fe\u534a\u6ee1\u7684\u90a3\u4e2a\u533a\u57df\uff09\uff0c\u540c\u65f6\u53ef\u80fd\u6709\u4e00\u4e9b\u6570\u636e\u79fb\u5230\u4e86 O \u533a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Eden \u5145\u6ee1\uff0c\u8fd9\u4e2a\u6211\u89e3\u91ca\u4e00\u4e0b\u3002G1 \u4e2d\u7684\u533a\u57df\u4f1a\u88ab\u903b\u8f91\u5206\u4e3a Eden \u533a\uff0cSurvivor \u533a\u53ca Old \u533a\u3002\u867d\u7136\u5b83\u4eec\u53ef\u80fd\u4e0d\u8fde\u7eed\uff0c\u4f46\u662f\u6bcf\u4e2a\u533a\u5757\u5360\u7528\u7684\u6bd4\u4f8b\u662f\u56fa\u5b9a\u7684\u3002Eden \u5145\u6ee1\uff0c\u4e5f\u53ef\u4ee5\u8bf4\u662f\u5360\u7528\u7684 Region \u8d85\u8fc7\u4e86\u4e00\u5b9a\u7684\u6bd4\u4f8b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">YGC \u53d1\u751f\u5728\u5e74\u8f7b\u4ee3\u7684 GC \u7b97\u6cd5\uff0c\u4e00\u822c\u5bf9\u8c61\uff08\u9664\u4e86\u5de8\u578b\u5bf9\u8c61\uff09\u90fd\u662f\u5728 eden region \u4e2d\u5206\u914d\u5185\u5b58\uff0c\u5f53\u6240\u6709 eden region \u88ab\u8017\u5c3d\u65e0\u6cd5\u7533\u8bf7\u5185\u5b58\u65f6\uff0c\u5c31\u4f1a\u89e6\u53d1\u4e00\u6b21 young gc\uff0c\u8fd9\u79cd\u89e6\u53d1\u673a\u5236\u548c\u4e4b\u524d\u7684 young gc \u5dee\u4e0d\u591a\uff0c\u6267\u884c\u5b8c\u4e00 \u6b21young gc\uff0c\u6d3b\u8dc3\u5bf9\u8c61\u4f1a\u88ab\u62f7\u8d1d\u5230 survivor region \u6216\u8005\u664b\u5347\u5230 old region \u4e2d\uff0c\u7a7a\u95f2\u7684 region \u4f1a\u88ab\u653e\u5165\u7a7a\u95f2\u5217\u8868\u4e2d\uff0c\u7b49\u5f85\u4e0b\u6b21\u88ab\u4f7f\u7528\u3002<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/wx1.sinaimg.cn\/large\/8fa5dcfcgy1g1pmfhejqnj209005i3z3.jpg\" alt=\"\" \/><figcaption>\u5e76\u53d1 G1 \u56de\u6536\u7684\u524d\u540e\u5bf9\u6bd4<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0a\u56fe\u662f\u4e00\u4e2a\u5e76\u53d1 G1 \u56de\u6536\u7684\u524d\u540e\u5bf9\u6bd4\u3002Young \u533a\u53d1\u751f\u4e86\u53d8\u5316\u3001\u8fd9\u610f\u5473\u7740\u5728 G1 \u5e76\u53d1\u9636\u6bb5\u5185\u81f3\u5c11\u53d1\u751f\u4e86\u4e00\u6b21 YGC\uff08\u8fd9\u70b9\u548c CMS \u5c31\u6709\u533a\u522b\uff09\uff0cEden \u5728\u6807\u8bb0\u4e4b\u524d\u5df2\u7ecf\u88ab\u5b8c\u5168\u6e05\u7a7a\uff0c\u56e0\u4e3a\u5728\u5e76\u53d1\u9636\u6bb5\u5e94\u7528\u7ebf\u7a0b\u540c\u65f6\u5728\u5de5\u4f5c\u3001\u6240\u4ee5\u53ef\u4ee5\u770b\u5230 Eden \u53c8\u6709\u65b0\u7684\u5360\u7528\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u4e9b\u533a\u57df\u88ab X \u6807\u8bb0\uff0c\u8fd9\u4e9b\u533a\u57df\u5c5e\u4e8e O \u533a\uff0c\u6b64\u65f6\u4ecd\u7136\u6709\u6570\u636e\u5b58\u653e\u3001\u4e0d\u540c\u4e4b\u5904\u5728 G1 \u5df2\u6807\u8bb0\u51fa\u8fd9\u4e9b\u533a\u57df\u5305\u542b\u7684\u5783\u573e\u6700\u591a\u3001\u4e5f\u5c31\u662f\u56de\u6536\u6536\u76ca\u6700\u9ad8\u7684\u533a\u57df\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5e76\u53d1\u9636\u6bb5\u5b8c\u6210\u4e4b\u540e\u5b9e\u9645\u4e0a O \u533a\u7684\u5bb9\u91cf\u53d8\u5f97\u66f4\u5927\u4e86\uff08O + X\u7684\u65b9\u5757\uff09\u3002\u8fd9\u65f6\u56e0\u4e3a\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\u53d1\u751f\u4e86 YGC \u6709\u65b0\u7684\u5bf9\u8c61\u8fdb\u5165\u6240\u81f4\u3002\u6b64\u5916\uff0c\u8fd9\u4e2a\u9636\u6bb5\u5728 O \u533a\u6ca1\u6709\u56de\u6536\u4efb\u4f55\u5bf9\u8c61\uff1a\u5b83\u7684\u4f5c\u7528\u4e3b\u8981\u662f\u6807\u8bb0\u51fa\u5783\u573e\u6700\u591a\u7684\u533a\u5757\u51fa\u6765\u3002\u5bf9\u8c61\u5b9e\u9645\u4e0a\u662f\u5728\u540e\u9762\u7684\u9636\u6bb5\u771f\u6b63\u5f00\u59cb\u88ab\u56de\u6536\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">G1 \u5e76\u53d1\u6807\u8bb0\u5468\u671f\u53ef\u4ee5\u5206\u6210\u51e0\u4e2a\u9636\u6bb5\u3001\u5176\u4e2d\u6709\u4e9b\u9700\u8981\u6682\u505c\u5e94\u7528\u7ebf\u7a0b\u3002\u7b2c\u4e00\u4e2a\u9636\u6bb5\u662f\u521d\u59cb\u6807\u8bb0\u9636\u6bb5\u3002\u8fd9\u4e2a\u9636\u6bb5\u4f1a\u6682\u505c\u6240\u6709\u5e94\u7528\u7ebf\u7a0b\uff0c\u90e8\u5206\u539f\u56e0\u662f\u8fd9\u4e2a\u8fc7\u7a0b\u4f1a\u6267\u884c\u4e00\u6b21 YGC\u3002\u7136\u540e\uff0c\u7b2c\u4e8c\u4e2a\u9636\u6bb5\u662f G1 \u5f00\u59cb\u626b\u63cf\u6839\u533a\u57df\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u6ca1\u6709\u6682\u505c\u5e94\u7528\u7ebf\u7a0b\uff0c\u662f\u540e\u53f0\u7ebf\u7a0b\u5e76\u884c\u5904\u7406\u7684\u3002\u8fd9\u4e2a\u9636\u6bb5\u4e0d\u80fd\u88abYGC\u6240\u6253\u65ad\u3001\u56e0\u6b64\u540e\u53f0\u7ebf\u7a0b\u6709\u8db3\u591f\u7684 CPU \u65f6\u95f4\u5f88\u5173\u952e\u3002\u7b2c\u4e09\u4e2a\u9636\u6bb5\u662f G1 \u8fdb\u5165\u4e86\u4e00\u4e2a\u5e76\u53d1\u6807\u8bb0\u9636\u6bb5\u3002\u8fd9\u4e2a\u9636\u6bb5\u4e5f\u662f\u5b8c\u5168\u540e\u53f0\u8fdb\u884c\u7684\uff0c\u5e76\u53d1\u6807\u8bb0\u9636\u6bb5\u662f\u53ef\u4ee5\u88ab\u6253\u65ad\u7684\u3002\u8fd9\u4e2a\u9636\u6bb5\u4e4b\u540e\u4f1a\u6709\u4e00\u4e2a\u4e8c\u6b21\u6807\u8bb0\u9636\u6bb5\u548c\u6e05\u7406\u9636\u6bb5\uff0c\u8fd9\u4e24\u4e2a\u9636\u6bb5\u540c\u6837\u4f1a\u6682\u505c\u5e94\u7528\u7ebf\u7a0b\uff0c\u4f46\u65f6\u95f4\u5f88\u77ed\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5e76\u53d1\u9636\u6bb5\u4e3b\u8981\u505a\u7684\u662f\u53d1\u73b0\u54ea\u4e9b\u533a\u57df\u5305\u542b\u53ef\u56de\u6536\u7684\u5783\u573e\u6700\u591a\uff08\u6807\u8bb0\u4e3aX\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u63a5\u4e0b\u6765 G1 \u6267\u884c\u4e00\u7cfb\u5217\u7684\u6df7\u5408 GC\u3002\u8fd9\u4e2a\u65f6\u671f\u56e0\u4e3a\u4f1a\u540c\u65f6\u8fdb\u884c YGC \u548c\u6e05\u7406\u4e0a\u9762\u5df2\u6807\u8bb0\u4e3a X \u7684\u533a\u57df\uff0c\u6240\u4ee5\u79f0\u4e4b\u4e3a\u6df7\u5408\u9636\u6bb5\u3002<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/wx1.sinaimg.cn\/large\/8fa5dcfcgy1g1pmhcykvzj208t05nq3h.jpg\" alt=\"\" \/><figcaption>G1 \u6df7\u5408\u9636\u6bb5<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u50cf\u666e\u901a\u7684 YGC \u90a3\u6837\u3001G1 \u5b8c\u5168\u6e05\u7a7a\u6389 Eden \u540c\u65f6\u8c03\u6574 survivor \u533a\u3002\u53e6\u5916\uff0c\u4e24\u4e2a\u6807\u8bb0\u4e5f\u88ab\u56de\u6536\u4e86\uff0c\u4ed6\u4eec\u6709\u4e2a\u5171\u540c\u7684\u7279\u70b9\u662f\u5305\u542b\u6700\u591a\u53ef\u56de\u6536\u7684\u5bf9\u8c61\uff0c\u56e0\u6b64\u8fd9\u4e24\u4e2a\u533a\u57df\u7edd\u5bf9\u90e8\u5206\u7a7a\u95f4\u90fd\u88ab\u91ca\u653e\u4e86\u3002\u8fd9\u4e24\u4e2a\u533a\u57df\u4efb\u4f55\u5b58\u6d3b\u7684\u5bf9\u8c61\u90fd\u88ab\u79fb\u5230\u4e86\u5176\u4ed6\u533a\u57df\uff08\u548c YGC \u5b58\u6d3b\u5bf9\u8c61\u664b\u5347\u5230 O \u533a\u7c7b\u4f3c\uff09\u3002\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48 G1 \u7684\u5806\u6bd4 CMS \u5185\u5b58\u788e\u7247\u8981\u5c11\u5f88\u591a\u7684\u539f\u56e0\u2013\u79fb\u52a8\u8fd9\u4e9b\u5bf9\u8c61\u7684\u540c\u65f6\u4e5f\u5c31\u662f\u5728\u538b\u7f29\u5bf9\u5185\u5b58\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6700\u540e\u7684 full gc\uff0c\u5982\u679c\u5bf9\u8c61\u5185\u5b58\u5206\u914d\u901f\u5ea6\u8fc7\u5feb\uff0cmixed(\u6df7\u5408) gc \u6765\u4e0d\u53ca\u56de\u6536\uff0c\u5bfc\u81f4\u8001\u5e74\u4ee3\u88ab\u586b\u6ee1\uff0c\u5c31\u4f1a\u89e6\u53d1\u4e00\u6b21 full gc\uff0cG1 \u7684 full gc \u7b97\u6cd5\u5c31\u662f\u5355\u7ebf\u7a0b\u6267\u884c\u7684 serial old gc\uff0c\u4f1a\u5bfc\u81f4\u5f02\u5e38\u957f\u65f6\u95f4\u7684\u6682\u505c\u65f6\u95f4\uff0c\u9700\u8981\u8fdb\u884c\u4e0d\u65ad\u7684\u8c03\u4f18\uff0c\u5c3d\u53ef\u80fd\u7684\u907f\u514d full gc\u3002<\/p>\n<!-- <audio autoplay=\"autoplay\" height=\"100\" width=\"100\" hidden=\"true\"><source src=\"https:\/\/c.coka.la\/orAvPR.mp3\" type=\"audio\/mp3\"\/><\/audio><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/ws3.sinaimg.cn\/large\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/> --><p><!-- <img decoding=\"async\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/>--><img decoding=\"async\" src=\"https:\/\/saas.51autoparts.cn\/api\/admin\/sys-file\/oss\/file?fileName=84db51f8561e448f9a4fda2eff0811f9.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/><\/p><p>\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01<b>\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1a<font color=\"red\">xttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p><p>\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a<a href=\"https:\/\/www.xttblog.com\">\u4e1a\u4f59\u8349<\/a>\uff1a &raquo; <a href=\"https:\/\/www.xttblog.com\/?p=4080\">\u559c\u6b22 G1 \u5783\u573e\u6536\u96c6\u5668\u5c31\u8981\u653e\u8086\uff0c\u7231\u4e0a CMS \u5783\u573e\u6536\u96c6\u5668\u8981\u514b\u5236<\/a><\/p><!-- <div class=\"bd-reward-stl\"><button id=\"bdRewardBtn\"><span><\/span><\/button><\/div> -->","protected":false},"excerpt":{"rendered":"<p>\u5728 JDK1.7 \u4e4b\u524d\uff0cCMS \u5783\u573e\u6536\u96c6\u5668\u662f\u4e3b\u6d41\u7684\u9009\u62e9\u3002\u4f46\u81ea\u4ece JDK 6u14 \u4f53\u9a8c\u7248\u672c\u9762\u4e16\uff0c\u5230 JDK 7 [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[1955,1174,262,1334,731],"class_list":["post-4080","post","type-post","status-publish","format-standard","hentry","category-java","tag-cms","tag-gc","tag-java","tag-jdk8","tag-jvm"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4080","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4080"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4080\/revisions"}],"predecessor-version":[{"id":4081,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4080\/revisions\/4081"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4080"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4080"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4080"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}