{"id":1377,"date":"2019-08-20T16:39:39","date_gmt":"2019-08-20T08:39:39","guid":{"rendered":"http:\/\/www.sniper97.cn\/?p=1377"},"modified":"2019-08-20T16:39:39","modified_gmt":"2019-08-20T08:39:39","slug":"%e3%80%90java%e8%99%9a%e6%8b%9f%e6%9c%ba%e3%80%91%e5%9e%83%e5%9c%be%e6%94%b6%e9%9b%86%e5%99%a8%e4%b8%8e%e5%86%85%e5%ad%98%e5%88%86%e9%85%8d%e7%ad%96%e7%95%a5","status":"publish","type":"post","link":"http:\/\/www.sniper97.cn\/index.php\/note\/jvm\/1377\/","title":{"rendered":"\u3010Java\u865a\u62df\u673a\u3011\u5783\u573e\u6536\u96c6\u5668\u4e0e\u5185\u5b58\u5206\u914d\u7b56\u7565"},"content":{"rendered":"\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"343\" height=\"711\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-20.png\" alt=\"\" class=\"wp-image-1402\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-20.png 343w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-20-145x300.png 145w\" sizes=\"(max-width: 343px) 100vw, 343px\" \/><\/figure><\/div>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"288\" height=\"176\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-21.png\" alt=\"\" class=\"wp-image-1403\"\/><\/figure><\/div>\n\n\n<p>\u4e0a\u4e00\u7bc7\u4ecb\u7ecd\u4e86Java\u5185\u5b58\u8fd0\u884c\u65f6\u533a\u57df\u7684\u5404\u4e2a\u90e8\u5206\uff0c\u5176\u4e2d\u7a0b\u5e8f\u8ba1\u6570\u5668\u3001\u865a\u62df\u673a\u6808\u3001\u672c\u5730\u65b9\u6cd5\u68083\u4e2a\u533a\u57df\u968f\u7ebf\u7a0b\u800c\u751f\uff0c\u968f\u7ebf\u7a0b\u800c\u706d\uff1a\u6808\u4e2d\u7684\u6808\u5e27\u968f\u7740\u65b9\u6cd5\u7684\u8fdb\u5165\u548c\u9000\u51fa\u800c\u6709\u6761\u4e0d\u7d0a\u5730\u6267\u884c\u7740\u51fa\u6808\u548c\u5165\u6808\u64cd\u4f5c\u3002\u6bcf\u4e00\u4e2a\u6808\u5e27\u4e2d\u5206\u914d\u591a\u5c11\u5185\u5b58\u57fa\u672c\u4e0a\u662f\u5728\u7c7b\u7ed3\u6784\u786e\u5b9a\u4e0b\u6765\u65f6\u5c31\u5df2\u77e5\u7684\uff0c\u56e0\u6b64\u8fd9\u51e0\u4e2a\u533a\u57df\u7684\u5185\u5b58\u5206\u914d\u548c\u56de\u6536\u90fd\u5177\u5907\u786e\u5b9a\u6027\uff0c\u5728\u8fd9\u51e0\u4e2a\u533a\u57df\u5185\u5c31\u4e0d\u9700\u8981\u8fc7\u591a\u8003\u8651\u56de\u6536\u7684\u95ee\u9898\uff0c\u56e0\u4e3a\u65b9\u6cd5\u7ed3\u675f\u6216\u8005\u7ebf\u7a0b\u7ed3\u675f\u65f6\uff0c\u5185\u5b58\u81ea\u7136\u5c31\u8ddf\u968f\u7740\u56de\u6536\u4e86\u3002\u800cJava\u5806\u548c\u65b9\u6cd5\u533a\u5219\u4e0d\u4e00\u6837\uff0c\u4e00\u4e2a\u63a5\u53e3\u4e2d\u7684\u591a\u4e2a\u5b9e\u73b0\u7c7b\u9700\u8981\u7684\u5185\u5b58\u53ef\u80fd\u4e0d\u4e00\u6837\uff0c\u4e00\u4e2a\u65b9\u6cd5\u4e2d\u7684\u591a\u4e2a\u5206\u652f\u9700\u8981\u7684\u5185\u5b58\u4e5f\u53ef\u80fd\u4e0d\u4e00\u6837\uff0c\u6211\u4eec\u53ea\u6709\u5728\u7a0b\u5e8f\u5904\u4e8e\u8fd0\u884c\u671f\u95f4\u65f6\u624d\u80fd\u77e5\u9053\u4f1a\u521b\u5efa\u54ea\u4e9b\u5bf9\u8c61\uff0c\u8fd9\u90e8\u5206\u5185\u5b58\u7684\u5206\u914d\u548c\u56de\u6536\u90fd\u662f\u52a8\u6001\u7684\uff0c\u5783\u573e\u6536\u96c6\u5668\u6240\u5173\u6ce8\u7684\u5c31\u662f\u8fd9\u90e8\u5206\u3002<\/p>\n\n\n<h2 class=\"wp-block-heading\">1.\u5bf9\u8c61\u5df2\u6b7b\u4e48<\/h2>\n\n\n<h3 class=\"wp-block-heading\">1.1 \u5f15\u7528\u8ba1\u6570\u7b97\u6cd5<\/h3>\n\n\n<p>\u5728\u5bf9\u8c61\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u5f15\u7528\u8ba1\u6570\u5668\uff0c\u6bcf\u5f53\u6709\u4e00\u4e2a\u5730\u65b9\u5f15\u7528\u5b83\u65f6\uff0c\u8ba1\u6570\u5668\u503c\u5c31+1\uff0c\u5f53\u5f15\u7528\u65f6\u6548\u65f6\uff0c\u8ba1\u6570\u5668\u503c\u5c31-1.\u4efb\u4f55\u65f6\u523b\u8ba1\u6570\u5668\u4e3a0\u7684\u5bf9\u8c61\u5c31\u662f\u4e0d\u53ef\u80fd\u518d\u88ab\u4f7f\u7528\u7684\u3002<\/p>\n\n\n<p>\u5f15\u7528\u8ba1\u6570\u6cd5\uff08Reference Counting\uff09\u7684\u5b9e\u73b0\u7b80\u5355\uff0c\u5224\u5b9a\u6548\u7387\u4e5f\u5f88\u9ad8\uff0c\u5728\u5927\u90e8\u5206\u60c5\u51b5\u4e0b\u5b83\u90fd\u662f\u4e00\u4e2a\u4e0d\u9519\u7684\u9009\u62e9\u3002\u4f46\u662f\uff0c\u81f3\u5c11\u4e3b\u6d41\u7684Java\u865a\u62df\u673a\u91cc\u90fd\u6ca1\u6709\u9009\u7528\u5f15\u7528\u8ba1\u6570\u7b97\u6cd5\u6765\u7ba1\u7406\u5185\u5b58\uff0c\u5176\u4e2d\u6700\u4e3b\u8981\u7684\u539f\u56e0\u662f\u5b83\u5f88\u96be\u89e3\u51b3\u5bf9\u8c61\u4e4b\u95f4\u76f8\u4e92\u5faa\u73af\u5f15\u7528\u7684\u95ee\u9898\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">1.2 \u53ef\u8fbe\u6027\u5206\u6790\u7b97\u6cd5<\/h3>\n\n\n<p>\u5728\u4e3b\u6d41\u7684\u5546\u7528\u7a0b\u5e8f\u8bed\u8a00\u7684\u4e3b\u6d41\u5b9e\u73b0\u4e2d\u90fd\u662f\u4f7f\u7528\u53ef\u8fbe\u6027\u5206\u6790\uff08Reachability Analysis\uff09\u6765\u5224\u65ad\u5bf9\u8c61\u662f\u5426\u5b58\u6d3b\u7684\u3002\u8fd9\u4e2a\u7b97\u6cd5\u7684\u57fa\u672c\u601d\u8def\u5c31\u662f\u901a\u8fc7\u4e00\u7cfb\u5217\u7684\u79f0\u4e3a\u201cGC Roots\u201d\u7684\u5bf9\u8c61\u4f5c\u4e3a\u8d77\u59cb\u70b9\uff0c\u4ece\u8fd9\u4e9b\u8282\u70b9\u5f00\u59cb\u5411\u4e0b\u641c\u7d22\uff0c\u641c\u7d22\u6240\u8d70\u8fc7\u7684\u8def\u5f84\u79f0\u4e3a\u5f15\u7528\u94fe\uff08Reference Chain\uff09\uff0c\u5f53\u4e00\u4e2a\u5bf9\u8c61\u5230GC Roots\u6ca1\u6709\u4efb\u4f55\u5f15\u7528\u94fe\u76f8\u8fde\u65f6\uff0c\u5219\u8bc1\u660e\u6b64\u5bf9\u8c61\u662f\u4e0d\u53ef\u7528\u7684\u3002<\/p>\n\n\n<p>\u5982\u56fe\uff1a\u5bf9\u8c61object 5\u3001object 6\u3001object 7\u867d\u7136\u4e92\u6709\u5173\u8054\uff0c\u4f46\u662f\u4ed6\u4eec\u5230GC Roots\u662f\u4e0d\u53ef\u8fbe\u7684\uff0c\u6240\u4ee5\u4ed6\u4eec\u5c06\u4f1a\u5224\u5b9a\u4e3a\u662f\u53ef\u56de\u6536\u7684\u5bf9\u8c61\u3002<\/p>\n\n<p><!--StartFragment--><\/p>\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"761\" height=\"448\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-13.png\" alt=\"\" class=\"wp-image-1380\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-13.png 761w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-13-300x177.png 300w\" sizes=\"(max-width: 761px) 100vw, 761px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">1.3 \u5f15\u7528<\/h3>\n\n\n<p>\u5728JDK1.2\u4e4b\u540e\uff0cJava\u5bf9\u5f15\u7528\u7684\u6982\u5ff5\u8fdb\u884c\u4e86\u6269\u5145\uff0c\u5c06\u5f15\u7528\u5206\u4e3a\u5f3a\u5f15\u7528\uff08Strong Reference\uff09\u3001\u8f6f\u5f15\u7528\uff08Soft Reference\uff09\u3001\u5f31\u5f15\u7528\uff08Weak Reference\uff09\u3001\u865a\u5f15\u7528\uff08Phantom Reference\uff094\u79cd\uff0c\u8fd94\u79cd\u5f15\u7528\u5f3a\u5ea6\u4f9d\u6b21\u51cf\u5f31\u3002<\/p>\n\n\n<p>\u5f3a\u5f15\u7528\u5c31\u662f\u6307\u5728\u7a0b\u5e8f\u4ee3\u7801\u4e4b\u4e2d\u666e\u904d\u5b58\u5728\u7684\uff0c\u7c7b\u4f3c\u201cObject obj = new 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class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"301\" height=\"129\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-16.png\" alt=\"\" class=\"wp-image-1384\"\/><\/figure><\/div>\n\n\n<p>\u53ef\u4ee5\u770b\u51fa\uff1aSAVE_HOOK\u5bf9\u8c61\u7684finalize\uff08\uff09\u65b9\u6cd5\u786e\u5b9e\u88abGC\u6536\u96c6\u5668\u89e6\u53d1\u8fc7\uff0c\u5e76\u4e14\u5728\u6536\u96c6\u524d\u6210\u529f\u9003\u8131\u4e86\u3002<\/p>\n\n\n<p>\u4ee3\u7801\u4e2d\u6709\u4e24\u6bb5\u5b8c\u5168\u4e00\u6837\u7684\u4ee3\u7801\u7247\u6bb5\uff0c\u6267\u884c\u7ed3\u679c\u5374\u662f\u4e00\u6b21\u9003\u8131\u6210\u529f\uff0c\u4e00\u6b21\u5931\u8d25\uff0c\u8fd9\u662f\u56e0\u4e3a\u4efb\u4f55\u4e00\u4e2a\u5bf9\u8c61\u7684finalize\uff08\uff09\u65b9\u6cd5\u90fd\u53ea\u4f1a\u88ab\u7cfb\u7edf\u81ea\u52a8\u7684\u8c03\u7528\u4e00\u6b21\uff0c\u5982\u679c\u5bf9\u8c61\u9762\u4e34\u4e0b\u4e00\u6b21\u56de\u6536\uff0c\u5b83\u7684finalize\uff08\uff09\u65b9\u6cd5\u4e0d\u4f1a\u88ab\u518d\u6b21\u6267\u884c\uff0c\u56e0\u6b64\u7b2c\u4e8c\u6bb5\u4ee3\u7801\u7684\u81ea\u6551\u884c\u52a8\u5931\u6548\u4e86\u3002<\/p>\n\n\n<p>\u4f46\u662f\u5728\u4efb\u4f55\u65f6\u5019\u4e0d\u5efa\u8bae\u4f7f\u7528finalize\uff08\uff09\u65b9\u6cd5\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">1.5 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class=\"wp-block-heading\">2.\u5783\u573e\u6536\u96c6\u7b97\u6cd5<\/h2>\n\n\n<h3 class=\"wp-block-heading\">2.1 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class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"802\" height=\"400\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-17.png\" alt=\"\" class=\"wp-image-1385\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-17.png 802w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-17-300x150.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-17-768x383.png 768w\" sizes=\"(max-width: 802px) 100vw, 802px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">2.2 \u590d\u5236\u7b97\u6cd5<\/h3>\n\n\n<p>\u4e3a\u4e86\u89e3\u51b3\u6548\u7387\u95ee\u9898\uff0c\u4e00\u79cd\u79f0\u4e3a\u590d\u5236\uff08Copying\uff09\u7684\u6536\u96c6\u7b97\u6cd5\u51fa\u73b0\u4e86\uff0c\u5b83\u5c06\u53ef\u7528\u5185\u5b58\u6309\u5bb9\u91cf\u5212\u5206\u4e3a\u5927\u5c0f\u76f8\u7b49\u7684\u4e24\u5757\uff0c\u6bcf\u6b21\u53ea\u4f7f\u7528\u5176\u4e2d\u4e00\u5757\u3002\u5f53\u8fd9\u4e00\u5757\u7684\u5185\u5b58\u7528\u5b8c\u4e86\uff0c\u5c31\u5c06\u8fd8\u5b58\u6d3b\u7740\u7684\u5bf9\u8c61\u590d\u5236\u5230\u53e6\u5916\u4e00\u5757\u4e0a\u9762\uff0c\u7136\u540e\u518d\u628a\u5df2\u4f7f\u7528\u8fc7\u7684\u5185\u5b58\u7a7a\u95f4\u4e00\u6b21\u6027\u6e05\u7406\u6389\u3002\u8fd9\u6837\u662f\u7684\u6bcf\u6b21\u90fd\u662f\u5bf9\u6574\u4e2a\u534a\u533a\u8fdb\u884c\u56de\u6536\uff0c\u5185\u5b58\u5206\u914d\u65f6\u4e5f\u5c31\u4e0d\u7528\u8003\u8651\u5185\u5b58\u788e\u7247\u7b49\u590d\u6742\u60c5\u51b5\uff0c\u53ea\u8981\u79fb\u52a8\u5806\u9876\u6307\u9488\uff0c\u6309\u987a\u5e8f\u5206\u914d\u5185\u5b58\u5373\u53ef\uff0c\u5b9e\u73b0\u7b80\u5355\uff0c\u8fd0\u884c\u9ad8\u6548\u3002\u53ea\u662f\u8fd9\u79cd\u7b97\u6cd5\u7684\u4ee3\u4ef7\u662f\u5c06\u5185\u5b58\u7f29\u5c0f\u4e3a\u4e86\u539f\u6765\u7684\u4e00\u534a\uff0c\u4ee3\u4ef7\u6709\u70b9\u592a\u9ad8\u3002<\/p>\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"745\" height=\"400\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-18.png\" alt=\"\" class=\"wp-image-1386\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-18.png 745w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-18-300x161.png 300w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/><\/figure>\n\n\n<p>\u73b0\u4ee3\u7684\u5546\u4e1a\u865a\u62df\u673a\u5e76\u4e0d\u662f\u6309\u71671\uff1a1\u7684\u6bd4\u4f8b\u6765\u5212\u5206\u5185\u5b58\u7a7a\u95f4\uff0c\u662f\u5c06\u5185\u5b58\u5206\u4e3a\u4e00\u5757\u8f83\u5927\u7684Eden\u7a7a\u95f4\u548c\u4e24\u5757\u8f83\u5c0f\u7684Survivor\u7a7a\u95f4\uff0c\u6bcf\u6b21\u4f7f\u7528Eden\u548c\u5176\u4e2d\u4e00\u5757\u7684Survivor\u3002\u5f53\u88ab\u56de\u6536\u65f6\uff0c\u5c06Eden\u548cSurvivor\u4e2d\u8fd8\u5b58\u6d3b\u7740\u7684\u5bf9\u8c61\u4e00\u6b21\u6027\u5730\u590d\u5236\u5230\u53e6\u4e00\u4e2aSurvivor\u533a\u57df\u4e2d\uff0c\u6700\u540e\u6e05\u7406\u6389Eden\u548c\u521a\u521a\u7528\u8fc7\u7684Survivor\u533a\u57df\u3002HotSpot\u9ed8\u8ba4\u7684Eden\u548cSurvivor\u6bd4\u4f8b\u4e3a8\uff1a1\u3002\u5f53Survivor\u7a7a\u95f4\u4e0d\u591f\u65f6\uff0c\u9700\u8981\u4f9d\u8d56\u5176\u4ed6\u5185\u5b58\uff08\u8001\u5e74\u4ee3\uff09\u8fdb\u884c\u5206\u914d\u62c5\u4fdd\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">2.2 \u6807\u8bb0-\u6574\u7406\u7b97\u6cd5<\/h3>\n\n\n<p>\u6839\u636e\u8001\u5e74\u4ee3\u7684\u7279\u70b9\uff0c\u6709\u4eba\u63d0\u51fa\u4e86\u53e6\u4e00\u79cd\u6807\u8bb0-\u6e05\u7406\uff08Mark-Compact\uff09\u7b97\u6cd5\uff0c\u6807\u8bb0\u8fc7\u7a0b\u4ecd\u7136\u4e0e\u6807\u8bb0-\u6e05\u9664\u7b97\u6cd5\u4e00\u6837\uff0c\u4f46\u540e\u7eed\u6b65\u9aa4\u4e0d\u662f\u76f4\u63a5\u5bf9\u53ef\u56de\u6536\u5bf9\u8c61\u8fdb\u884c\u6574\u7406\uff0c\u800c\u662f\u8ba9\u6240\u6709\u5b58\u6d3b\u7684\u5bf9\u8c61\u90fd\u5411\u4e00\u7aef\u8fdb\u884c\u79fb\u52a8\uff0c\u7136\u540e\u76f4\u63a5\u6e05\u7406\u6389\u7aef\u8fb9\u754c\u4ee5\u5916\u7684\u5185\u5b58\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"758\" height=\"403\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-19.png\" alt=\"\" class=\"wp-image-1387\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-19.png 758w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-19-300x159.png 300w\" sizes=\"(max-width: 758px) 100vw, 758px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">2.3 \u5206\u4ee3\u6536\u96c6\u7b97\u6cd5<\/h3>\n\n\n<p>\u5f53\u4ee3\u5546\u4e1a\u865a\u62df\u673a\u7684\u5783\u573e\u6536\u96c6\u90fd\u91c7\u7528\u201c\u5206\u4ee3\u6536\u96c6\u201d\uff08Generational Collection\uff09\u7b97\u6cd5\uff0c\u8fd9\u79cd\u7b97\u6cd5\u5e76\u6ca1\u6709\u4ec0\u4e48\u65b0\u7684\u601d\u8def\uff0c\u53ea\u662f\u6839\u636e\u5bf9\u8c61\u5b58\u8d27\u5468\u671f\u7684\u4e0d\u540c\u5c06\u5185\u5b58\u5212\u5206\u4e3a\u51e0\u5757\u3002\u4e00\u822c\u662f\u628aJava\u5806\u5206\u4e3a\u65b0\u751f\u4ee3\u548c\u8001\u5e74\u4ee3\uff0c\u8fd9\u6837\u5c31\u53ef\u4ee5\u6839\u636e\u5404\u4e2a\u5e74\u4ee3\u7684\u7279\u70b9\u91c7\u7528\u6700\u9002\u5f53\u7684\u6536\u96c6\u7b97\u6cd5\u3002\u5728\u65b0\u751f\u4ee3\u4e2d\uff0c\u6bcf\u6b21\u5783\u573e\u6536\u96c6\u65f6\u90fd\u53d1\u73b0\u6709\u5927\u6279\u5bf9\u8c61\u6b7b\u53bb\uff0c\u53ea\u6709\u5c11\u6570\u5b58\u6d3b\uff0c\u90a3\u5c31\u9009\u7528\u590d\u5236\u7b97\u6cd5\uff0c\u53ea\u9700\u8981\u4ed8\u51fa\u5c11\u91cf\u5b58\u8d27\u5bf9\u8c61\u7684\u590d\u5236\u6210\u672c\u5c31\u53ef\u4ee5\u5b8c\u6210\u6536\u96c6\u3002\u800c\u8001\u5e74\u4ee3\u4e2d\u56e0\u4e3a\u5bf9\u8c61\u5b58\u6d3b\u7387\u9ad8\uff0c\u6ca1\u6709\u989d\u5916\u7a7a\u95f4\u5bf9\u5b83\u8fdb\u884c\u5206\u914d\u62c5\u4fdd\uff0c\u5c31\u5fc5\u987b\u4f7f\u7528\u6807\u8bb0-\u6e05\u7406\u6216\u8005\u6807\u8bb0-\u6574\u7406\u7b97\u6cd5\u6765\u8fdb\u884c\u56de\u6536\u3002<\/p>\n\n\n<h2 class=\"wp-block-heading\">3 HotSpot\u7684\u7b97\u6cd5\u5b9e\u73b0<\/h2>\n\n\n<h3 class=\"wp-block-heading\">3.1 \u679a\u4e3e\u6839\u8282\u70b9<\/h3>\n\n\n<p>\u53ef\u8fbe\u6027\u5206\u6790\u5bf9\u6267\u884c\u65f6\u95f4\u7684\u654f\u611f\u8fd8\u4f53\u73b0\u5728GC\u505c\u987f\u4e0a\uff0c\u56e0\u4e3a\u8fd9\u9879\u5206\u6790\u5de5\u4f5c\u5fc5\u987b\u5728\u4e00\u4e2a\u80fd\u786e\u4fdd\u4e00\u81f4\u6027\u7684\u5feb\u7167\u4e2d\u8fdb\u884c\u2014\u2014\u8fd9\u91cc\u7684\u4e00\u81f4\u6027\u7684\u610f\u601d\u662f\u6307\u5728\u6574\u4e2a\u5206\u6790\u671f\u95f4\u6574\u4e2a\u6267\u884c\u7cfb\u7edf\u770b\u8d77\u6765\u5c31\u50cf\u88ab\u51bb\u7ed3\u5728\u67d0\u4e2a\u65f6\u95f4\u4e00\u6837\uff0c\u4e0d\u53ef\u4ee5\u51fa\u73b0\u5206\u6790\u8fc7\u7a0b\u4e2d\u5bf9\u8c61\u5f15\u7528\u5173\u7cfb\u8fd8\u5728\u4e0d\u65ad\u53d8\u5316\u7684\u60c5\u51b5\uff0c\u8be5\u5e97\u4e0d\u6ee1\u8db3\u7684\u8bdd\u5206\u6790\u7ed3\u679c\u51c6\u786e\u6027\u5c31\u65e0\u6cd5\u4fdd\u8bc1\u3002\u8fd9\u70b9\u662f\u5bfc\u81f4GC\u8fdb\u884c\u65f6\u5fc5\u987b\u505c\u987f\u6240\u6709Java\u6267\u884c\u7ebf\u7a0b\uff08Sun\u516c\u53f8\u5c06\u5176\u79f0\u4f5c\u4e3aStop The World\uff09\u7684\u5176\u4e2d\u4e00\u4e2a\u91cd\u8981\u539f\u56e0\uff0c\u5373\u4f7f\u662f\u5728\u53f7\u79f0\uff08\u51e0\u4e4e\uff09\u4e0d\u4f1a\u53d1\u751f\u505c\u987f\u7684CMS\u6536\u96c6\u5668\u4e2d\uff0c\u679a\u4e3e\u6839\u8282\u70b9\u65f6\u4e5f\u662f\u5fc5\u987b\u8981\u505c\u987f\u7684\u3002<\/p>\n\n\n<p>\u76ee\u524d\u4e3b\u6d41\u662f\u865a\u62df\u673a\u4f7f\u7528\u7684\u90fd\u662f\u51c6\u786e\u5f0fGC:\u5728HotSpot\u7684\u5b9e\u73b0\u4e2d\uff0c\u662f\u4f7f\u7528\u4e00\u7ec4\u79f0\u4e3aOopMap\u7684\u6570\u636e\u7ed3\u6784\u6765\u6253\u5230\u8fd9\u4e2a\u76ee\u7684\u7684\uff0c\u5728\u7c7b\u52a0\u8f7d\u5b8c\u6210\u7684\u65f6\u5019\uff0cHotSpot\u5c31\u628a\u5bf9\u8c61\u5185\u4ec0\u4e48\u504f\u79fb\u91cf\u4e0a\u662f\u4ec0\u4e48\u7c7b\u578b\u7684\u6570\u636e\u8ba1\u7b97\u51fa\u6765\uff0c\u5728JIT\u7f16\u8bd1\u8fc7\u7a0b\u4e2d\uff0c\u4e5f\u4f1a\u5728\u7279\u5b9a\u7684\u4f4d\u7f6e\uff08VM\u77e5\u9053\u6bcf\u4e2a\u5730\u65b9\u7684\u6570\u636e\u662f\u4ec0\u4e48\u7c7b\u578b\uff09\u8bb0\u5f55\u4e0b\u6808\u548c\u5bc4\u5b58\u5668\u4e2d\u54ea\u4e9b\u4f4d\u7f6e\u662f\u5f15\u7528\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">3.2 \u5b89\u5168\u70b9<\/h3>\n\n\n<p>\u5b9e\u9645\u4e0a\uff0cHotSpot\u5e76\u6ca1\u6709\u4e3a\u6bcf\u6761\u6307\u4ee4\u90fd\u751f\u6210OopMap\uff0c\u6b63\u5982\u524d\u9762\u63d0\u5230\u7684\uff0c\u4f1a\u5728\u201c\u7279\u5b9a\u7684\u4f4d\u7f6e\u201d\u8bb0\u5f55\u8fd9\u4e9b\u4fe1\u606f\uff0c\u8fd9\u4e9b\u4f4d\u7f6e\u79f0\u4e3a\u5b89\u5168\u70b9\uff08Safepoint\uff09\uff0c\u5373\u7a0b\u5e8f\u6267\u884c\u65f6\u5e76\u975e\u5728\u6240\u6709\u5730\u65b9\u90fd\u80fd\u505c\u987f\u4e0b\u6765\u5f00\u59cbGC\uff0c\u53ea\u6709\u5230\u8fbe\u5b89\u5168\u70b9\u65f6\u624d\u80fd\u6682\u505c\u3002<\/p>\n\n\n<p>\u6240\u4ee5\uff0c\u5b89\u5168\u70b9\u7684\u9009\u5b9a\u57fa\u672c\u4e0a\u662f\u4ee5\u7a0b\u5e8f\u201c\u662f\u5426\u5177\u6709\u8ba9\u7a0b\u5e8f\u957f\u65f6\u95f4\u6267\u884c\u7684\u7279\u5f81\u201d\u4e3a\u6807\u51c6\u8fdb\u884c\u9009\u5b9a\u7684\u2014\u2014\u56e0\u4e3a\u6bcf\u6761\u6307\u4ee4\u6267\u884c\u7684\u65f6\u95f4\u90fd\u975e\u5e38\u77ed\u6682\uff0c\u7a0b\u5e8f\u4e0d\u592a\u53ef\u80fd\u56e0\u4e3a\u6307\u4ee4\u6d41\u957f\u5ea6\u592a\u957f\u8fd9\u4e2a\u539f\u56e0\u800c\u8fc7\u957f\u65f6\u95f4\u8fd0\u884c\uff0c\u201c\u957f\u65f6\u95f4\u6267\u884c\u201d\u7684\u6700\u660e\u663e\u7279\u5f81\u5c31\u662f\u6307\u4ee4\u5e8f\u5217\u91cd\u590d\uff0c\u4f8b\u5982\u65b9\u6cd5\u8c03\u7528\u3001\u5faa\u73af\u8df3\u8f6c\u3001\u5f02\u5e38\u8df3\u8f6c\u7b49\uff0c\u6240\u4ee5\u5177\u6709\u8fd9\u4e9b\u529f\u80fd\u7684\u6307\u4ee4\u624d\u4f1a\u4ea7\u751fSafepoint\u3002<\/p>\n\n\n<p>\u5bf9\u4e8eSafepoint\uff0c\u53e6\u4e00\u4e2a\u95ee\u9898\u662f\u5982\u4f55\u5728GC\u53d1\u751f\u65f6\u5982\u4f55\u8ba9\u6240\u6709\u7ebf\u7a0b\u90fd\u201c\u8dd1\u201d\u6253\u8dd1\u6700\u8fd1\u7684\u5b89\u5168\u70b9\u4e0a\u518d\u505c\u987f\u4e0b\u6765\u3002\u8fd9\u91cc\u6709\u4e24\u79cd\u65b9\u6848\u53ef\u4f9b\u9009\u62e9\uff1a\u62a2\u5148\u5f0f\u4e2d\u65ad\uff08Preemptive Suspension\uff09\u548c\u4e3b\u52a8\u5f0f\u4e2d\u65ad\uff08Voluntary Suspension\uff09\u3002<\/p>\n\n\n<p>\u62a2\u5148\u5f0f\u4e2d\u65ad\u4e0d\u9700\u8981\u73b0\u6210\u7684\u6267\u884c\u4ee3\u7801\u4e3b\u52a8\u53bb\u914d\u5408\uff0c\u5728GC\u53d1\u751f\u65f6\uff0c\u9996\u5148\u628a\u6240\u6709\u7ebf\u7a0b\u5168\u90e8\u4e2d\u65ad\uff0c\u5982\u679c\u53d1\u73b0\u6709\u7ebf\u7a0b\u4e2d\u65ad\u7684\u5730\u65b9\u4e0d\u5728\u5b89\u5168\u70b9\u4e0a\uff0c\u5c31\u6062\u590d\u7ebf\u7a0b\uff0c\u8ba9\u5b83\u8dd1\u5230\u5b89\u5168\u70b9\u4e0a\u3002\u73b0\u5728\u51e0\u4e4e\u6ca1\u6709\u865a\u62df\u673a\u91c7\u7528\u62a2\u5148\u5f0f\u4e2d\u65ad\u6765\u6682\u505c\u7ebf\u7a0b\u4ece\u800c\u54cd\u5e94GC\u4e8b\u4ef6\u3002<\/p>\n\n\n<p>\u4e3b\u52a8\u5f0f\u4e2d\u65ad\u7684\u601d\u60f3\u662f\u5f53GC\u9700\u8981\u4e2d\u65ad\u7ebf\u7a0b\u7684\u65f6\u5019\uff0c\u4e0d\u76f4\u63a5\u5bf9\u7ebf\u7a0b\u64cd\u4f5c\uff0c\u4ec5\u4ec5\u7b80\u5355\u5730\u8bbe\u7f6e\u4e00\u4e2a\u6807\u5fd7\uff0c\u5404\u4e2a\u7ebf\u7a0b\u6267\u884c\u65f6\u4e3b\u52a8\u53bb\u8f6e\u8be2\u8fd9\u4e2a\u6807\u5fd7\uff0c\u53d1\u73b0\u4e2d\u65ad\u6807\u5fd7\u4e3a\u771f\u65f6\u5c31\u81ea\u5df1\u4e2d\u65ad\u6302\u8d77\u3002\u8f6e\u8be2\u6807\u5fd7\u7684\u5730\u65b9\u548c\u5b89\u5168\u70b9\u662f\u91cd\u5408\u7684\uff0c\u53e6\u5916\u518d\u52a0\u4e0a\u521b\u5efa\u5bf9\u8c61\u9700\u8981\u5206\u914d\u5185\u5b58\u7684\u5730\u65b9\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">3.3 \u5b89\u5168\u533a\u57df<\/h3>\n\n\n<p>\u4f7f\u7528Safepoint\u4f3c\u4e4e\u5df2\u7ecf\u5b8c\u7f8e\u89e3\u51b3\u4e86\u5982\u4f55\u8fdb\u5165GC\u7684\u95ee\u9898\uff0c\u4f46\u5b9e\u9645\u60c5\u51b5\u5374\u5e76\u4e0d\u4e00\u5b9a\u3002Safepoint\u673a\u5236\u4fdd\u8bc1\u4e86\u7a0b\u5e8f\u6267\u884c\u65f6\uff0c\u5728\u4e0d\u592a\u957f\u7684\u65f6\u95f4\u5185\u5c31\u4f1a\u9047\u5230\u53ef\u8fdb\u5165\u7684GC\u7684Safepoint\u3002\u4f46\u662f\uff0c\u7a0b\u5e8f\u201c\u4e0d\u6267\u884c\u201d\u7684\u65f6\u5019\u5462\uff1f\u6240\u8c13\u7684\u7a0b\u5e8f\u4e0d\u6267\u884c\u5c31\u662f\u6ca1\u6709\u5206\u914dCPU\u65f6\u95f4\uff0c\u5178\u578b\u7684\u4f8b\u5b50\u5c31\u662f\u7ebf\u7a0b\u5904\u4e8eSleep\u72b6\u6001\u6216\u8005Blocked\u72b6\u6001\uff0c\u8fd9\u65f6\u5019\u7ebf\u7a0b\u65e0\u6cd5\u54cd\u5e94JVM\u7684\u4e2d\u65ad\u8bf7\u6c42\uff0c\u201c\u8d70\u201d\u5230\u5b89\u5168\u7684\u5730\u65b9\u53bb\u4e2d\u65ad\u6302\u8d77\uff0cJVM\u4e5f\u663e\u7136\u4e0d\u592a\u53ef\u80fd\u7b49\u5f85\u7ebf\u7a0b\u91cd\u65b0\u88ab\u5206\u914dCPU\u65f6\u95f4\u3002\u5bf9\u4e8e\u8fd9\u79cd\u60c5\u51b5\uff0c\u5c31\u9700\u8981\u5b89\u5168\u533a\u57df\uff08Safe Region\uff09\u6765\u89e3\u51b3\u3002<\/p>\n\n\n<p>\u5b89\u5168\u533a\u57df\u662f\u6307\u5728\u4e00\u6bb5\u4ee3\u7801\u7247\u6bb5\u4e4b\u4e2d\uff0c\u5f15\u7528\u5173\u7cfb\u4e0d\u4f1a\u53d1\u751f\u53d8\u5316\u3002\u5728\u8fd9\u4e2a\u533a\u57df\u4e2d\u7684\u4efb\u610f\u5730\u65b9\u5f00\u59cbGC\u90fd\u662f\u5b89\u5168\u7684\u3002\u6211\u4eec\u4e5f\u53ef\u4ee5\u628aSafe Region\u770b\u4f5c\u662f\u88ab\u6269\u5c55\u4e86\u7684Safepoint\u3002<\/p>\n\n\n<p>\u5728\u7ebf\u7a0b\u6267\u884c\u5230Safe Region\u4e2d\u7684\u4ee3\u7801\u65f6\uff0c\u9996\u5148\u6807\u8bc6\u81ea\u5df1\u5df2\u7ecf\u8fdb\u5165\u5230\u4e86Safe Region\uff0c\u90a3\u6837\uff0c\u5f53\u5728\u8fd9\u6bb5\u65f6\u95f4\u91ccJVM\u8981\u53d1\u8d77GC\u65f6\uff0c\u5c31\u4e0d\u7528\u7ba1\u8868\u793a\u81ea\u5df1\u4e3aSafe Region\u7684\u7ebf\u7a0b\u4e86\u3002\u5728\u7ebf\u7a0b\u8981\u79bb\u5f00\u5b89\u5168\u533a\u57df\u65f6\uff0c\u5b83\u8981\u68c0\u67e5\u7cfb\u7edf\u662f\u5426\u5df2\u7ecf\u5b8c\u6210\u4e86\u6839\u8282\u70b9\u679a\u4e3e\uff08\u6216\u8005\u662f\u6574\u4e2aGC\u8fc7\u7a0b\uff09\u3002\u5982\u679c\u5b8c\u6210\u4e86\uff0c\u90a3\u7ebf\u7a0b\u5c31\u7ee7\u7eed\u6267\u884c\uff0c\u5426\u5219\u5b83\u5fc5\u987b\u7b49\u5f85\u76f4\u5230\u6536\u5230\u53ef\u4ee5\u5b89\u5168\u79bb\u5f00\u5b89\u5168\u533a\u57df\u7684\u4fe1\u53f7\u4e3a\u6b62\u3002<\/p>\n\n\n<h2 class=\"wp-block-heading\">4.\u5783\u573e\u6536\u96c6\u5668<\/h2>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"505\" height=\"454\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-22.png\" alt=\"\" class=\"wp-image-1405\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-22.png 505w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-22-300x270.png 300w\" sizes=\"(max-width: 505px) 100vw, 505px\" \/><\/figure><\/div>\n\n\n<p>\u5982\u679c\u4e24\u79cd\u6536\u96c6\u5668\u4e4b\u95f4\u5b58\u5728\u8fde\u7ebf\uff0c\u5c31\u8bf4\u660e\u4ed6\u4eec\u53ef\u4ee5\u642d\u914d\u4f7f\u7528\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">4.1 Serial \u6536\u96c6\u5668<\/h3>\n\n\n<p>Serial\u624b\u673a\u5176\u5b9e\u6700\u57fa\u672c\u3001\u53d1\u5c55\u5386\u53f2\u6700\u60a0\u4e45\u7684\u6536\u96c6\u5668\uff0c\u66fe\u7ecf\u662f\u65b0\u751f\u4ee3\u6536\u96c6\u5668\u7684\u552f\u4e00\u9009\u62e9\u3002\u8fd9\u4e2a\u6536\u96c6\u5668\u662f\u4e00\u4e2a\u5355\u7ebf\u7a0b\u7684\u6536\u96c6\u5668\uff0c\u4f46\u5b83\u7684\u201c\u5355\u7ebf\u7a0b\u201d\u7684\u610f\u4e49\u5e76\u4e0d\u4ec5\u4ec5\u8bf4\u660e\u4ed6\u53ea\u4f1a\u4f7f\u7528\u4e00\u4e2aCPU\u6216\u4e00\u6761\u6536\u96c6\u7ebf\u7a0b\u53bb\u5b8c\u6210\u5783\u573e\u6536\u96c6\u5de5\u4f5c\uff0c\u66f4\u91cd\u8981\u7684\u662f\u4ed6\u8fdb\u884c\u5783\u573e\u6536\u96c6\u65f6\uff0c\u5fc5\u987b\u6682\u505c\u5176\u4ed6\u6240\u6709\u7684\u5de5\u4f5c\u7ebf\u7a0b\uff0c\u76f4\u5230\u5b83\u6536\u96c6\u7ed3\u675f\u3002<\/p>\n\n\n<p>\u867d\u7136\u8fdb\u884c\u5783\u573e\u6536\u96c6\u65f6\uff0c\u4f1a\u201cStop the World\u201d\uff0c\u4f46\u5b83\u4f9d\u7136\u662f\u865a\u62df\u673a\u8fd0\u884c\u5728Client\u6a21\u5f0f\u4e0b\u9ed8\u8ba4\u7684\u65b0\u751f\u4ee3\u6536\u96c6\u5668\u3002\u4ed6\u7684\u4f18\u70b9\u5728\u4e8e\u7b80\u5355\u9ad8\u6548\u3002<\/p>\n\n\n<p>\u5bf9\u4e8e\u9650\u5b9a\u5355\u4e2aCPU\u7684\u73af\u5883\u6765\u8bf4\uff0cSerial\u6536\u96c6\u5668\u7531\u4e8e\u6ca1\u6709\u7ebf\u7a0b\u4ea4\u4e92\u7684\u5f00\u9500\uff0c\u4e13\u5fc3\u505a\u5783\u573e\u6536\u96c6\u81ea\u7136\u53ef\u4ee5\u83b7\u5f97\u6700\u9ad8\u7684\u5355\u7ebf\u7a0b\u6536\u96c6\u6548\u7387\u3002\u5728\u7528\u6237\u7684\u684c\u9762\u5e94\u7528\u573a\u666f\u4e2d\uff0c\u5206\u914d\u7ed9\u865a\u62df\u673a\u7ba1\u7406\u7684\u5185\u5b58\u4e00\u822c\u6765\u8bf4\u4e0d\u4f1a\u5f88\u5927\uff0c\u6536\u96c6\u51e0\u5341\u5146\u751a\u81f3\u4e00\u4e24\u767e\u5146\u7684\u65b0\u751f\u4ee3\uff0c\u505c\u987f\u65f6\u95f4\u5b8c\u5168\u53ef\u4ee5\u63a7\u5236\u5728\u51e0\u5341\u6beb\u79d2\u6700\u591a\u4e00\u767e\u591a\u6beb\u79d2\u4ee5\u5185\uff0c\u53ea\u8981\u4e0d\u662f\u9891\u7e41\u53d1\u751f\uff0c\u8fd9\u70b9\u505c\u987f\u662f\u53ef\u4ee5\u63a5\u53d7\u7684\u3002\u6240\u4ee5Serial\u6536\u96c6\u5668\u5bf9\u4e8e\u8fd0\u884c\u5728Client\u6a21\u5f0f\u4e0b\u7684\u865a\u62df\u673a\u6765\u8bf4\u662f\u4e00\u4e2a\u5f88\u597d\u7684\u9009\u62e9\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"827\" height=\"145\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-23.png\" alt=\"\" class=\"wp-image-1407\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-23.png 827w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-23-300x53.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-23-768x135.png 768w\" sizes=\"(max-width: 827px) 100vw, 827px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">4.2 ParNew \u6536\u96c6\u5668<\/h3>\n\n\n<p>ParNew\u6536\u96c6\u5668\u5176\u5b9e\u5c31\u662fSerial\u6536\u96c6\u5668\u7684\u591a\u7ebf\u7a0b\u7248\u672c\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"816\" height=\"172\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-24.png\" alt=\"\" class=\"wp-image-1408\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-24.png 816w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-24-300x63.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-24-768x162.png 768w\" sizes=\"(max-width: 816px) 100vw, 816px\" \/><\/figure><\/div>\n\n\n<p>ParNew\u6536\u96c6\u5668\u5728\u5355CPU\u7684\u73af\u5883\u4e2d\u7edd\u5bf9\u4e0d\u4f1a\u6bd4Serial\u6536\u96c6\u5668\u7684\u6548\u679c\u66f4\u597d\uff0c\u751a\u81f3\u7531\u4e8e\u5b58\u5728\u7ebf\u7a0b\u4ea4\u4e92\u7684\u5f00\u9500\uff0c\u8be5\u6536\u96c6\u5668\u5728\u901a\u8fc7\u8d85\u7ebf\u7a0b\u6280\u672f\u5b9e\u73b0\u4e24\u4e2aCPU\u7684\u73af\u5883\u4e2d\u90fd\u4e0d\u80fd\u767e\u5206\u767e\u5730\u4fdd\u8bc1\u53ef\u4ee5\u8d85\u8d8aSerial\u6536\u96c6\u5668\u3002\u5f53\u7136\uff0c\u968f\u7740\u53ef\u4ee5\u4f7f\u7528\u7684CPU\u6570\u91cf\u7684\u589e\u52a0\uff0c\u5b83\u5bf9\u4e8eGC\u65f6\u7cfb\u7edf\u8d44\u6e90\u7684\u6709\u6548\u5229\u7528\u8fd8\u662f\u5f88\u6709\u597d\u5904\u7684\u3002\u5b83\u9ed8\u8ba4\u5f00\u542f\u7684\u6536\u96c6\u7ebf\u7a0b\u6570\u548cCPU\u4e2a\u6570\u76f8\u540c\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">4.3 Parallel Scavenge \u6536\u96c6\u5668<\/h3>\n\n\n<p>Parallel Scavenge\u6536\u96c6\u5668\u662f\u4e00\u4e2a\u65b0\u751f\u4ee3\u6536\u96c6\u5668\uff0c\u5b83\u4e5f\u662f\u4f7f\u7528\u590d\u5236\u7b97\u6cd5\u7684\u6536\u96c6\u5668\uff0c\u53c8\u662f\u5e76\u884c\u7684\u591a\u7ebf\u7a0b\u6536\u96c6\u5668\u3002<\/p>\n\n\n<p>Parallel Scavenge\u6536\u96c6\u5668\u7684\u7279\u70b9\u662f\u5b83\u7684\u5173\u6ce8\u70b9\u4e0e\u5176\u4ed6\u6536\u96c6\u5668\u4e0d\u540c\uff0cCMS\u7b49\u6536\u96c6\u5668\u7684\u5173\u6ce8\u70b9\u662f\u5c3d\u53ef\u80fd\u5730\u7f29\u77ed\u5783\u573e\u6536\u96c6\u65f6\u7528\u6237\u7ebf\u7a0b\u7684\u505c\u987f\u65f6\u95f4\uff0c\u800cParallel Scavenge\u6536\u96c6\u5668\u7684\u76ee\u6807\u5219\u662f\u8fbe\u5230\u4e00\u4e2a\u53ef\u63a7\u5236\u7684\u541e\u5410\u91cf\uff08Throughput\uff09\u3002\u6240\u8c13\u541e\u5410\u91cf\u5c31\u662fCPU\u7528\u4e8e\u8fd0\u884c\u7528\u6237\u4ee3\u7801\u7684\u65f6\u95f4\u4e0eCPU\u603b\u6d88\u8017\u65f6\u95f4\u7684\u6bd4\u503c\u3002\u4f8b\u5982\u865a\u62df\u673a\u603b\u5171\u8fd0\u884c\u4e86100\u5206\u949f\uff0c\u5176\u4e2d\u5783\u573e\u56de\u6536\u82b1\u8d39\u4e861\u5206\u949f\uff0c\u90a3\u541e\u5410\u91cf\u5c31\u662f99%\u3002<\/p>\n\n\n<p>Parallel Scavenge\u6536\u96c6\u5668\u4e5f\u5e38\u5e38\u88ab\u79f0\u4f5c\u201c\u541e\u5410\u91cf\u4f18\u5148\u201d\u6536\u96c6\u5668\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">4.4 Serial Old \u6536\u96c6\u5668<\/h3>\n\n\n<p>Serial Old\u662fSerial\u6536\u96c6\u5668\u7684\u8001\u5e74\u4ee3\u7248\u672c\uff0c\u5b83\u540c\u6837\u662f\u4e00\u4e2a\u5355\u7ebf\u7a0b\u6536\u96c6\u5668\uff0c\u4f7f\u7528\u201c\u6807\u8bb0-\u6e05\u7406\u201d\u7b97\u6cd5\u3002\u8fd9\u4e2a\u6536\u96c6\u5668\u7684\u4e3b\u8981\u610f\u4e49\u4e5f\u662f\u5728\u4e8e\u7ed9Client\u6a21\u5f0f\u4e0b\u7684\u865a\u62df\u673a\u4f7f\u7528\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"835\" height=\"166\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-25.png\" alt=\"\" class=\"wp-image-1410\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-25.png 835w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-25-300x60.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-25-768x153.png 768w\" sizes=\"(max-width: 835px) 100vw, 835px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">4.5 Parallel Old \u6536\u96c6\u5668<\/h3>\n\n\n<p>Parallel Old\u662fParallel Scavenge\u6536\u96c6\u5668\u7684\u8001\u5e74\u4ee3\u7248\u672c\uff0c\u4f7f\u7528\u591a\u7ebf\u7a0b\u548c\u201c\u6807\u8bb0-\u6574\u7406\u201d\u7b97\u6cd5\uff0c\u8fd9\u4e2a \u6536\u96c6\u5668\u662f\u5728JDK1.6\u4e4b\u540e\u624d\u5f00\u59cb\u63d0\u4f9b\u7684\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"837\" height=\"165\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-26.png\" alt=\"\" class=\"wp-image-1412\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-26.png 837w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-26-300x59.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-26-768x151.png 768w\" sizes=\"(max-width: 837px) 100vw, 837px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">4.6 CMS \u6536\u96c6\u5668<\/h3>\n\n\n<p>CMS\uff08Concurrent Mark Sweep\uff09\u6536\u96c6\u5668\u662f\u4e00\u79cd\u4ee5\u83b7\u53d6\u6700\u77ed\u505c\u987f\u65f6\u95f4\u4e3a\u76ee\u6807\u7684\u6536\u96c6\u5668\u3002\u76ee\u524d\u5f88\u5927\u4e00\u90e8\u5206\u7684Java\u5e94\u7528\u96c6\u4e2d\u5728\u4e92\u8054\u7f51\u7ad9\u6216\u8005B\/S\u7cfb\u7edf\u7684\u670d\u52a1\u7aef\u4e0a\uff0c\u8fd9\u7c7b\u5e94\u7528\u5c24\u5176\u91cd\u89c6\u670d\u52a1\u7684\u54cd\u5e94\u901f\u5ea6\uff0c\u5e0c\u671b\u7cfb\u7edf\u505c\u987f\u65f6\u95f4\u6700\u77ed\uff0c\u4ee5\u7ed9\u7528\u6237\u6765\u8f83\u597d\u7684\u4f53\u9a8c\u3002CMS\u6536\u96c6\u5668\u5c31\u975e\u5e38\u7b26\u5408\u8fd9\u7c7b\u5e94\u7528\u7684\u9700\u6c42\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"823\" height=\"175\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-27.png\" alt=\"\" class=\"wp-image-1413\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-27.png 823w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-27-300x64.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-27-768x163.png 768w\" sizes=\"(max-width: 823px) 100vw, 823px\" \/><\/figure><\/div>\n\n\n<p>CMS\u6536\u96c6\u5668\u5bf9\u8d44\u6e90\u5341\u5206\u654f\u611f\u3002\u5728\u5e76\u53d1\u9636\u6bb5\uff0c\u5b83\u867d\u7136\u4e0d\u4f1a\u5bfc\u81f4\u7528\u6237\u7ebf\u7a0b\u505c\u987f\uff0c\u4f46\u662f\u4f1a\u56e0\u4e3a\u5360\u7528\u7387\u4e00\u90e8\u5206\u7ebf\u7a0b\u800c\u5bfc\u81f4\u5e94\u7528\u7a0b\u5e8f\u53d8\u6162\uff0c\u603b\u541e\u5410\u91cf\u4f1a\u964d\u4f4e\u3002CMS\u9ed8\u8ba4\u542f\u52a8\u7684\u6536\u96c6\u7ebf\u7a0b\u6570\u91cf\u662f\uff08CPU\u6570\u91cf+3\uff09\/4\uff0c\u4e5f\u5c31\u662f\u5f53CPU\u57284\u4e2a\u4ee5\u4e0a\u65f6\uff0c\u5e76\u53d1\u56de\u6536\u65f6\u5783\u573e\u6536\u96c6\u7ebf\u7a0b\u4e0d\u5c11\u4e8e25%\u7684CPU\u8d44\u6e90\uff0c\u5e76\u4e14\u968f\u7740CPU\u6570\u91cf\u7684\u589e\u52a0\u800c\u4e0b\u964d\u3002\u4f46\u662f\u5f53\u4e0d\u8db34\u4e2aCPU\u65f6\uff0c\u6027\u80fd\u4e0b\u964d\u7684\u5c31\u6bd4\u8f83\u5927\u3002<\/p>\n\n\n<p>CMS\u6536\u96c6\u5668\u65e0\u6cd5\u5904\u7406\u6d6e\u52a8\u5783\u573e\uff08Floating Garbage\uff09\u3002\u7531\u4e8eCMS\u5e76\u53d1\u6e05\u7406\u9636\u6bb5\u7528\u6237\u7ebf\u7a0b\u8fd8\u5728\u8fd0\u884c\u7740\uff0c\u4f34\u968f\u7a0b\u5e8f\u8fd0\u884c\u81ea\u7136\u5c31\u8fd8\u4f1a\u6709\u65b0\u7684\u5783\u573e\u4e0d\u65ad\u4ea7\u751f\uff0c\u8fd9\u4e00\u90e8\u5206\u5783\u573e\u51fa\u73b0\u5728\u6807\u8bb0\u8fc7\u7a0b\u4e4b\u540e\uff0cCMS\u65e0\u6cd5\u5728\u5f53\u6b21\u6536\u96c6\u4e2d\u5904\u7406\u6389\u5b83\u4eec\uff0c\u53ea\u597d\u7559\u5f85\u4e0b\u4e00\u6b21GC\u65f6\u518d\u6e05\u7406\u6389\u3002\u8fd9\u4e00\u90e8\u5206\u5783\u573e\u5c31\u6210\u4e3a\u201c\u6d6e\u52a8\u5783\u573e\u201d\u3002<\/p>\n\n\n<p>CMS\u8fd8\u6709\u4e00\u4e2a\u7f3a\u70b9\uff0c\u7531\u4e8e\u662f\u57fa\u4e8e\u201c\u6807\u8bb0-\u6e05\u9664\u201d\u7b97\u6cd5\u5b9e\u73b0\u7684\u6536\u96c6\u5668\uff0c\u624b\u673a\u7ed3\u675f\u65f6\u4f1a\u4ea7\u751f\u5927\u91cf\u7684\u7a7a\u95f4\u788e\u7247\uff0c\u7a7a\u95f4\u788e\u7247\u8fc7\u591a\u65f6\uff0c\u5c06\u4f1a\u7ed9\u5927\u5bf9\u8c61\u5206\u914d\u5e26\u6765\u5f88\u5927\u7684\u9ebb\u70e6\uff0c\u5f80\u5f80\u4f1a\u51fa\u73b0\u8001\u5e74\u4ee3\u8fd8\u6709\u5f88\u5927\u7684\u7a7a\u95f4\u5269\u4f59\uff0c\u4f46\u662f\u65e0\u6cd5\u627e\u5230\u8db3\u591f\u5927\u7684\u8fde\u7eed\u7a7a\u95f4\u6765\u5206\u914d\u5f53\u524d\u5bf9\u8c61\uff0c\u4e0d\u5f97\u4e0d\u63d0\u524d\u51fa\u53d1\u4e00\u6b21Full GC\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">4.7 G1 \u6536\u96c6\u5668<\/h3>\n\n\n<p>G1\uff08Garbage-First\uff09\u6536\u96c6\u5668\u662f\u5f53\u4eca\u6536\u96c6\u5668\u6280\u672f\u53d1\u5c55\u7684\u6700\u524d\u6cbf\u6280\u672f\u3002<\/p>\n\n\n<p>\u5e76\u884c\u4e0e\u5e76\u53d1\uff1aG1\u80fd\u5145\u5206\u5229\u7528\u591aCPU\u3001\u591a\u6838\u73af\u5883\u4e0b\u7684\u786c\u4ef6\u4f18\u52bf\uff0c\u4f7f\u7528\u591a\u4e2aCPU\u6765\u7f29\u77edStop the 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Set\u6765\u907f\u514d\u5168\u76d8\u626b\u63cf\u7684\u3002G1\u4e2d\u6bcf\u4e2aRegion\u90fd\u6709\u4e00\u4e2a\u4e0e\u4e4b\u5bf9\u5e94\u7684Remembered Set\uff0c\u865a\u62df\u673a\u53d1\u73b0\u7a0b\u5e8f\u5728\u5bf9Reference\u7c7b\u578b\u7684\u6570\u636e\u8fdb\u884c\u5199\u64cd\u4f5c\u65f6\uff0c\u4f1a\u4ea7\u751f\u4e00\u4e2aWrite Barrier\u6682\u65f6\u4e2d\u65ad\u5199\u64cd\u4f5c\uff0c\u68c0\u67e5Reference\u5f15\u7528\u7684\u5bf9\u8c61\u662f\u5426\u5904\u4e8e\u4e0d\u540c\u7684Region\u4e4b\u4e2d\uff08\u5728\u5206\u4ee3\u7684\u4f8b\u5b50\u4e2d\u5c31\u662f\u68c0\u67e5\u662f\u5426\u8001\u5e74\u4ee3\u4e2d\u7684\u5bf9\u8c61\u5f15\u7528\u4e86\u65b0\u751f\u4ee3\u4e2d\u7684\u5bf9\u8c61\uff09\uff0c\u5982\u679c\u662f\uff0c\u4fbf\u901a\u8fc7CardTable\u628a\u76f8\u5173\u5f15\u7528\u4fe1\u606f\u8bb0\u5f55\u5230\u88ab\u5f15\u7528\u5bf9\u8c61\u6240\u5c5e\u7684Region\u7684Remembered Set\u4e2d\u3002\u5f53\u8fdb\u884c\u5185\u5b58\u56de\u6536\u65f6\uff0c\u5728GC\u6839\u8282\u70b9\u7684\u679a\u4e3e\u8303\u56f4\u4e2d\u52a0\u5165Remembered Set\u5373\u53ef\u4fdd\u8bc1\u4e0d\u5bf9\u5168\u5806\u626b\u63cf\u4e5f\u4e0d\u4f1a\u6709\u9057\u6f0f\u3002<\/p>\n\n\n<p>\u5728G1\u5de5\u4f5c\u65f6\uff0c\u521d\u59cb\u6807\u8bb0\u9636\u6bb5\u4ec5\u4ec5\u662f\u6807\u8bb0\u4e00\u4e0bGC Roots\u80fd\u76f4\u63a5\u5173\u8054\u5230\u7684\u5bf9\u6027\u7231\u90a3\u4e2a\uff0c\u8fd9\u4e2a\u9636\u6bb5\u9700\u8981\u505c\u987f\u7ebf\u7a0b\uff0c\u4f46\u662f\u8017\u65f6\u5f88\u77ed\u3002\u5e76\u53d1\u6807\u8bb0\u9636\u6bb5\u662f\u4eceGC Roots\u5f00\u59cb\u5bf9\u5806\u4e2d\u7684\u5bf9\u8c61\u8fdb\u884c\u53ef\u8fbe\u6027\u5206\u6790\uff0c\u627e\u51fa\u5b58\u6d3b\u7684\u5bf9\u8c61\uff0c\u8fd9\u9636\u6bb5\u8017\u65f6\u8f83\u957f\uff0c\u4f46\u53ef\u4e0e\u7528\u6237\u7a0b\u5e8f\u5e76\u53d1\u6267\u884c\u3002\u6700\u7ec8\u6807\u8bb0\u9636\u6bb5\u5219\u662f\u4e3a\u4e86\u4fee\u6b63\u6b63\u5728\u5e76\u53d1\u6807\u8bb0\u671f\u95f4\u56e0\u7528\u6237\u7a0b\u5e8f\u7ee7\u7eed\u8fd0\u4f5c\u800c\u5bfc\u81f4\u6807\u8bb0\u4ea7\u751f\u53d8\u52a8\u7684\u90a3\u4e00\u90e8\u5206\u6807\u8bb0\u8bb0\u5f55\uff0c\u865a\u62df\u673a\u5c06\u8fd9\u6bb5\u65f6\u95f4\u5bf9\u8c61\u53d8\u5316\u8bb0\u5f55\u5728\u7ebf\u7a0bRemembered Set Logs\u91cc\u9762\uff0c\u6700\u7ec8\u6807\u8bb0\u9636\u6bb5\u9700\u8981\u628aRemembered Set Logs\u7684\u6570\u636e\u5408\u5e76\u5230Remembered Set\u4e2d\uff0c\u8fd9\u9636\u6bb5\u9700\u8981\u505c\u987f\u7ebf\u7a0b\uff0c\u4f46\u662f\u53ef\u5e76\u884c\u6267\u884c\u3002\u6700\u540e\u518d\u7b5b\u9009\u56de\u9996\u9636\u6bb5\u9996\u5148\u5bf9\u5404\u4e2aRegion\u7684\u56de\u6536\u4ef7\u503c\u548c\u6210\u672c\u8fdb\u884c\u6392\u5e8f\uff0c\u6839\u636e\u7528\u6237\u6240\u671f\u671b\u7684GC\u505c\u987f\u65f6\u95f4\u6765\u5236\u5b9a\u56de\u6536\u8ba1\u5212\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"857\" height=\"174\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-28.png\" alt=\"\" class=\"wp-image-1420\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-28.png 857w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-28-300x61.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-28-768x156.png 768w\" sizes=\"(max-width: 857px) 100vw, 857px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">4.8 \u7406\u89e3GC\u65e5\u5fd7<\/h3>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"836\" height=\"131\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-29.png\" alt=\"\" class=\"wp-image-1422\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-29.png 836w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-29-300x47.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-29-768x120.png 768w\" sizes=\"(max-width: 836px) 100vw, 836px\" \/><\/figure><\/div>\n\n\n<p>\u6700\u524d\u9762\u7684\u6570\u5b5733.125\u548c100.667\u4ee3\u8868\u4e86GC\u53d1\u751f\u7684\u65f6\u95f4\uff0c\u8fd9\u4e2a\u6570\u5b57\u7684\u542b\u4e49\u662f\u4eceJava\u865a\u62df\u673a\u542f\u52a8\u4ee5\u6765\u7ecf\u8fc7\u7684\u79d2\u6570\u3002<\/p>\n\n\n<p>[GC\u548c[FullGC\u8bf4\u4e86\u8fd9\u6b21\u5783\u573e\u6536\u96c6\u7684\u505c\u987f\u7c7b\u578b\u3002<\/p>\n\n\n<p>3324K-&gt;152K(3712K)\u542b\u4e49\u662fGC\u524d\u8be5\u5185\u5b58\u533a\u57df\u5df2\u4f7f\u7528\u5bb9\u91cf -&gt; GC\u540e\u8be5\u5185\u5b58\u533a\u57df\u5df2\u4f7f\u7528\u5bb9\u91cf\uff08\u8be5\u5185\u5b58\u533a\u57df\u603b\u5bb9\u91cf\uff09\u3002<\/p>\n\n\n<p>3324K -&gt; 152K\uff0811904K\uff09\u8868\u793aGC\u524dJava\u5806\u5df2\u4f7f\u7528\u5bb9\u91cf -&gt; GC\u540eJava\u5806\u5df2\u4f7f\u7528\u5bb9\u91cf\uff08Java\u5806\u603b\u5bb9\u91cf\uff09\u3002<\/p>\n\n\n<p>0.0025925 secs\u8868\u793a\u8be5\u5185\u5b58\u533a\u57dfGC\u6240\u5360\u7528\u7684\u65f6\u95f4\uff0c\u5355\u4f4d\u662f\u79d2\u3002<\/p>\n\n\n<h2 class=\"wp-block-heading\">5. \u5185\u5b58\u5206\u914d\u4e0e\u56de\u6536\u7b56\u7565<\/h2>\n\n\n<p>Java\u6280\u672f\u4f53\u7cfb\u4e2d\u6240\u63d0\u5021\u7684\u81ea\u52a8\u5185\u5b58\u7ba1\u7406\u6700\u7ec8\u53ef\u4ee5\u5f52\u7ed3\u4e3a\u81ea\u52a8\u5316\u5730\u89e3\u51b3\u4e86\u4e24\u4e2a\u95ee\u9898\uff1a\u7ed9\u5bf9\u8c61\u5206\u914d\u5185\u5b58\u4ee5\u53ca\u56de\u6536\u5206\u914d\u7ed9\u5bf9\u8c61\u7684\u5185\u5b58\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">5.1 \u5bf9\u8c61\u4f18\u5148\u5728Eden\u5206\u914d<\/h3>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"823\" height=\"315\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-30.png\" alt=\"\" class=\"wp-image-1424\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-30.png 823w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-30-300x115.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-30-768x294.png 768w\" sizes=\"(max-width: 823px) 100vw, 823px\" \/><\/figure><\/div>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"830\" height=\"427\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-31.png\" alt=\"\" class=\"wp-image-1425\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-31.png 830w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-31-300x154.png 300w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-31-768x395.png 768w\" sizes=\"(max-width: 830px) 100vw, 830px\" \/><\/figure><\/div>\n\n\n<p>\u8fd9\u6b21GC\u53d1\u751f\u7684\u539f\u56e0\u662fallocation4\u5206\u914d\u5185\u5b58\u7684\u65f6\u5019\uff0c\u53d1\u73b0Eden\u5df2\u7ecf\u88ab\u5360\u7528\u4e866MB\uff0c\u5269\u4f59\u7a7a\u95f4\u5df2\u7ecf\u4e0d\u8db3\u4ee5\u5206\u914d allocation4\u6240\u9700\u76844MB\u5185\u5b58\uff0c\u56e0\u6b64\u53d1\u751fMinor GC\u3002GC\u671f\u95f4\u865a\u62df\u673a\u53c8\u53d1\u73b0\u81ea\u5df1\u6709\u76843\u4e2a2MB\u5927\u5c0f\u7684\u5bf9\u8c61\u5168\u90e8\u65e0\u6cd5\u653e\u5165Survivor\u7a7a\u95f4\uff08Survivor\u53ea\u67091MB\u5927\u5c0f\uff09\uff0c\u6240\u4ee5\u53ea\u597d\u901a\u8fc7\u5206\u914d\u62c5\u4fdd\u673a\u5236\u63d0\u524d\u8f6c\u79fb\u5230\u8001\u5e74\u4ee3\u53bb\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">5.2 \u5927\u5bf9\u8c61\u76f4\u63a5\u8fdb\u5165\u8001\u5e74\u4ee3<\/h3>\n\n\n<p> \u865a\u62df\u673a\u63d0\u4f9b\u4e00\u4e2a-XX\uff1aPretenureSizeThreshold\u53c2\u6570\uff0c\u4ee4\u5927\u4e8e\u8fd9\u4e2a\u8bbe\u7f6e\u503c\u7684\u5bf9\u8c61\u76f4\u63a5\u5728\u8001\u5e74\u4ee3\u5206\u914d\u3002\u8fd9\u6837\u505a\u7684\u76ee\u7684\u662f\u907f\u514d\u5728Eden\u533a\u4ee5\u53caSurvivor\u533a\u4e4b\u95f4\u53d1\u751f\u5927\u91cf\u7684\u5185\u5b58\u590d\u5236\uff08\u590d\u4e60\u4e00\u4e0b\uff0c\u65b0\u751f\u4ee3\u91c7\u7528\u590d\u5236\u7b97\u6cd5\u6536\u96c6\u5185\u5b58\uff09\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">5.3 \u957f\u671f\u5b58\u6d3b\u7684\u5bf9\u8c61\u5c06\u8fdb\u5165\u8001\u5e74\u4ee3<\/h3>\n\n\n<p>\u4e3a\u4e86\u505a\u5230\u8fd9\u4e00\u70b9\uff0c\u865a\u62df\u673a\u7ed9\u6bcf\u4e2a\u5bf9\u8c61\u5b9a\u4e49\u4e86\u4e00\u4e2a\u5bf9\u8c61\u5e74\u9f84\uff08Age\uff09\u8ba1\u6570\u5668\u3002\u5982\u679c\u5bf9\u8c61\u5728Eden\u51fa\u751f\u5e76\u7ecf\u8fc7\u7b2c\u4e00\u6b21Minor GC\u540e\u4ecd\u7136\u5b58\u6d3b\uff0c\u5e76\u4e14\u80fd\u88abSurvivor\u5bb9\u7eb3\u7684\u8bdd\uff0c\u5c06\u88ab\u79fb\u52a8\u5230Survivor\u7a7a\u95f4\u4e2d\uff0c\u5e76\u4e14\u5bf9\u8c61\u5e74\u9f84\u8bbe\u4e3a1\u3002\u5bf9\u8c61\u5728Survivor\u533a\u4e2d\u6bcf\u71ac\u8fc7\u4e00\u6b21Minor GC\uff0c\u5e74\u9f84\u5c31\u4f1a\u589e\u52a01\u5c81\uff0c\u5f53\u4ed6\u7684\u5e74\u9f84\u589e\u52a0\u5230\u4e00\u5b9a\u7a0b\u5ea6\uff08\u9ed8\u8ba4\u4e3a15\u5c81\uff09\uff0c\u5c31\u5c06\u4f1a\u88ab\u664b\u5347\u5230\u8001\u5e74\u4ee3\u4e2d\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">5.4 \u52a8\u6001\u5bf9\u8c61\u5e74\u9f84\u7ed1\u5b9a<\/h3>\n\n\n<p>\u865a\u62df\u673a\u5e76\u4e0d\u662f\u6c38\u8fdc\u5730\u8981\u6c42\u5bf9\u8c61\u7684\u5e74\u9f84\u5fc5\u987b\u8fbe\u5230\u4e86MaxTenuringThreshold\u624d\u80fd\u664b\u5347\u8001\u5e74\u4ee3\uff0c\u5982\u679c\u5728Survivor\u7a7a\u95f4\u4e2d\u76f8\u540c\u5e74\u9f84\u6240\u6709\u5bf9\u8c61\u5927\u5c0f\u7684\u603b\u548c\u5927\u4e8eSurvivor\u7a7a\u95f4\u7684\u4e00\u534a\uff0c\u5e74\u9f84\u5927\u4e8e\u6216\u7b49\u4e8e\u8be5\u5e74\u9f84\u7684\u5bf9\u8c61\u5c31\u53ef\u4ee5\u76f4\u63a5\u8fdb\u5165\u8001\u5e74\u4ee3\uff0c\u65e0\u987b\u7b49\u5f85 MaxTenuringThreshold \u4e2d\u8981\u6c42\u7684\u5e74\u9f84\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">5.5 \u7a7a\u95f4\u5206\u914d\u62c5\u4fdd<\/h3>\n\n\n<p>\u5728\u53d1\u751fMinor GC\u4e4b\u524d\uff0c\u865a\u62df\u673a\u4f1a\u5148\u68c0\u67e5\u8001\u5e74\u4ee3\u6700\u5927\u53ef\u7528\u7684\u8fde\u7eed\u7a7a\u95f4\u662f\u5426\u5927\u4e8e\u65b0\u751f\u4ee3\u6240\u6709\u5bf9\u8c61\u603b\u7a7a\u95f4\uff0c\u5982\u679c\u8fd9\u4e2a\u6761\u4ef6\u6210\u7acb\uff0c\u90a3\u4e48Minor GC\u53ef\u4ee5\u786e\u4fdd\u662f\u5b89\u5168\u7684\u3002\u5982\u679c\u4e0d\u6210\u7acb\uff0c\u5219\u865a\u62df\u673a\u4f1a\u67e5\u770bHandlePromotionFailure\u8bbe\u7f6e\u503c\u662f\u5426\u5141\u8bb8\u62c5\u4fdd\u5931\u8d25\u3002\u5982\u679c\u5141\u8bb8\uff0c\u90a3\u4e48\u4f1a\u7ee7\u7eed\u68c0\u67e5\u8001\u5e74\u4ee3\u6700\u5927\u53ef\u7528\u7684\u8fde\u7eed\u7a7a\u95f4\u662f\u5426\u5927\u4e8e\u5386\u6b21\u664b\u5347\u5230\u8001\u5e74\u4ee3\u5bf9\u8c61\u7684\u5e73\u5747\u5927\u5c0f\uff0c\u5982\u679c\u5927\u4e8e\u5c06\u5c1d\u8bd5\u7740\u8fdb\u884c\u4e00\u6b21Minor GC\uff0c\u5c3d\u7ba1\u8fd9\u6b21Minor GC\u662f\u6709\u98ce\u9669\u7684\uff1b\u5982\u679c\u5c0f\u4e8e\uff0c\u6216\u8005HandlePromotionFailure\u8bbe\u7f6e\u4e0d\u5141\u8bb8\u5192\u9669\uff0c\u90a3\u4e48\u8fd9\u65f6\u5019\u8981\u6539\u4e3a\u4e00\u6b21Full GC\u3002<\/p>\n\n\n<p>JDK6 update24\u4e4b\u540e\u7684\u89c4\u5b9a\u53d8\u4e3a\u53ea\u8981\u8001\u5e74\u4ee3\u7684\u8fde\u7eed\u7a7a\u95f4\u5927\u4e8e\u65b0\u751f\u4ee3\u5bf9\u8c61\u603b\u5927\u5c0f\u6216\u8005\u5386\u6b21\u664b\u5347\u7684\u5e73\u5747\u5927\u5c0f\u5c31\u4f1a\u8fdb\u884cMinor GC\uff0c\u5426\u5219\u5c06\u8fdb\u884cFull GC\u3002<\/p>\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e0a\u4e00\u7bc7\u4ecb\u7ecd\u4e86Java\u5185\u5b58\u8fd0\u884c\u65f6\u533a\u57df\u7684\u5404\u4e2a\u90e8\u5206\uff0c\u5176\u4e2d\u7a0b\u5e8f\u8ba1\u6570\u5668\u3001\u865a\u62df\u673a\u6808\u3001\u672c\u5730\u65b9\u6cd5\u68083\u4e2a\u533a\u57df\u968f\u7ebf\u7a0b\u800c\u751f [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_mi_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[21],"tags":[],"views":3682,"_links":{"self":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/posts\/1377"}],"collection":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/comments?post=1377"}],"version-history":[{"count":0,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/posts\/1377\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/media?parent=1377"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/categories?post=1377"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/tags?post=1377"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}