{"id":286,"date":"2017-01-11T14:44:14","date_gmt":"2017-01-11T05:44:14","guid":{"rendered":"http:\/\/www.mukgee.com\/?p=286"},"modified":"2017-01-11T14:44:14","modified_gmt":"2017-01-11T05:44:14","slug":"gc%ea%b0%80%eb%b9%84%ec%a7%80-%ec%bb%ac%eb%9e%99%ed%84%b0%ec%9d%98-%ec%95%8c%ea%b3%a0%eb%a6%ac%ec%a6%98","status":"publish","type":"post","link":"http:\/\/mukgee.com\/?p=286","title":{"rendered":"GC(\uac00\ube44\uc9c0 \uceec\ub799\ud130)\uc758 \uc54c\uace0\ub9ac\uc998"},"content":{"rendered":"<p>\uc790\ubc14\ub294 \uac1c\ubc1c\uc790\uac00 \uba54\ubaa8\ub9ac\ub97c \uba85\uc2dc\uc801\uc73c\ub85c \ud574\uc9c0 \ud558\uc9c0 \uc54a\uace0 GC\uac00 \ub354 \uc774\uc0c1 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294 \uac1d\uccb4\uc5d0 \ub300\ud574 \uba54\ubaa8\ub9ac\ub97c \ud574\uc9c0 \ud558\ub294 \uc791\uc5c5\uc744 \uc9c4\ud589\ud55c\ub2e4. GC\uc5d0 \ub300\ud574 \uc774\ud574\ud558\uae30 \uc704\ud574\uc11c\ub294 \uc790\ubc14\uc758 \uba54\ubaa8\ub9ac \ud560\ub2f9 \ubc29\uc2dd\uc5d0 \ub300\ud574 \uba3c\uc800 \uc54c\ud544\uc694\uac00 \uc788\ub294\ub370 ,<\/p>\n<p>\uc790\ubc14\uac00 \uc0ac\uc6a9\ud558\ub294 \uba54\ubaa8\ub9ac \uc601\uc5ed\uc740 \ud06c\uac8c PC\ub808\uc9c0\uc2a4\ud130 , JVM \uc2a4\ud0dd , Heap , \uba54\uc11c\ub4dc \uc601\uc5ed, \ub7f0\ud0c0\uc784 \uc0c1\uc218 \ud480 , \ub124\uc774\ud2f0\ube0c \uba54\uc11c\ub4dc \uc2a4\ud0dd\uc774 \uc788\ub2e4.\u00a0(\uc790\uc138\ud55c\uac74 \uc5ec\uae30\u00a0<a href=\"http:\/\/docs.oracle.com\/javase\/specs\/jvms\/se8\/html\/jvms-2.html#jvms-2.5\" target=\"_blank\" rel=\"noopener noreferrer\">http:\/\/docs.oracle.com\/javase\/specs\/jvms\/se8\/html\/jvms-2.html#jvms-2.5<\/a>) \u00a0\uc774 \uc911 <span style=\"color: #3366ff;\"><strong>CG\uc758 \ub300\uc0c1\uc774 \ub418\ub294 \uc601\uc5ed\uc740 Heap \uc601\uc5ed\uc778\ub370 \uc778\uc2a4\ud134\uc2a4 \uac1d\uccb4\ub098 array\uac00 \uc313\uc774\ub294 \uba54\ubaa8\ub9ac \uc601\uc5ed<\/strong><\/span>\uc774\ub2e4.<\/p>\n<p>\uc774 Heap\uc601\uc5ed\uc5d0 \ub300\ud574 JVM\uc740 \ubb3c\ub9ac\uc801 \uacf5\uac04\uc744 \ud06c\uac8c \ub450\uac00\uc9c0\ub85c \ub098\ub204\uc5c8\ub2e4. <span style=\"color: #3366ff;\">Young \uc601\uc5ed, Old \uc601\uc5ed<\/span>.<\/p>\n<p>\uba85\uce6d\ub300\ub85c Young \uc601\uc5ed\uc5d0\ub294 \ucd5c\uadfc\uc5d0 \uc0dd\uc131\ub41c \uac1d\uccb4\ub4e4\uc774 \ud560\ub2f9 \ub418\uace0, Old\uc601\uc5ed\uc5d0\ub294 Young \uc601\uc5ed\uc5d0\uc11c \uba87\ubc88\uc758 GC\uc774 \uc2e4\ud589 \ub41c \ud6c4 \uc0dd\uc874\ud55c \uac1d\uccb4\ub4e4\uc774 \uc62e\uaca8 \uc624\ub294 \uc601\uc5ed\uc774\ub2e4.<\/p>\n<p>Young \uc601\uc5ed\ubcf4\ub2e4\ub294 Old\uc601\uc5ed\uc758 \ud06c\uae30\uac00 \ud070\ub370, \uc774 \ub54c\ubb38\uc5d0 Young \uc601\uc5ed\uc5d0\uc11c\uc758 GC \uc791\uc5c5\uc740 minor GC\ub77c\uace0 \ubd80\ub974\uace0 Old\uc601\uc5ed\uc740 Major GC(Full GC)\ub77c\uace0 \ubd80\ub978\ub2e4.<\/p>\n<p>Young \uc601\uc5ed \uc740 \ub2e4\uc2dc Eden , Survivor \uc601\uc5ed\uc73c\ub85c \ub098\ub220\uc9c0\ub294\ub370, \uc774\uae00\uc744 \uc791\uc131\ud558\uae30 \uc704\ud574 \ucc38\uc870\ud55c naver D2\uc758 \uae00\uc5d0 \ubcf4\uba74,<\/p>\n<p><em>Eden \uc601\uc5ed\uc5d0 \ucd5c\ucd08\ub85c \uac1d\uccb4\uac00 \ub9cc\ub4e4\uc5b4\uc9c0\uace0, Survivor \uc601\uc5ed\uc744 \ud1b5\ud574\uc11c Old \uc601\uc5ed\uc73c\ub85c \uc624\ub798 \uc0b4\uc544\ub0a8\uc740 \uac1d\uccb4\uac00 \uc774\ub3d9\ud55c\ub2e4\ub294 \uc0ac\uc2e4\uc740 \uaf2d \uae30\uc5b5\ud558\uae30 \ubc14\ub780\ub2e4.<\/em><\/p>\n<p>\ub77c\uace0 \ub418\uc5b4 \uc788\ub2e4. \uaf2d \uae30\uc5b5\ud558\uc790.<\/p>\n<p>GC\uc758 \uc54c\uace0\ub9ac\uc998\uc744 \uc774\ud574\ud558\uace0 \uc0c1\ud669\uc5d0 \ub530\ub77c \uc54c\ub9de\ub294 \uc54c\uace0\ub9ac\uc998\uc744 \uc120\ud0dd\ud574\uc57c\ud558\ub294 \uc774\uc720\ub294, JVM\uc5d0\uc11c GC\uac00 \uc77c\uc5b4\ub0a0\uacbd\uc6b0 GC\ub97c \uc2e4\ud589\ud558\ub294 \uc2a4\ub808\ub4dc\ub97c \uc81c\uc678\ud558\uace0 \ubaa8\ub4e0 \uc2a4\ub808\ub4dc\ub294 \uc815\uc9c0\ub41c\ub2e4. \uc774 \uc21c\uac04\uc744 stop the world\ub77c\uace0 \ubd80\ub974\uba70, \uc774 stop the world\uc758 \uc2dc\uac04\uc744 \uc904\uc774\ub294\uac83\uc774 GC \ud29c\ub2dd\uc758 \ud575\uc2ec\uc774\ub77c\uace0 \uc774\uc57c\uae30\ud55c\ub2e4. CPU\/\uba54\ubaa8\ub9ac \ub4f1\uc758 \uc5ec\ub7ec \uc870\uac74\uc744 \ubcf4\uace0 \ud6a8\uacfc\uc801\uc778 \uc54c\uace0\ub9ac\uc998\uc744 \uc120\ud0dd\ud558\uc5ec <span style=\"color: #3366ff;\">stop the world\ub97c \uc904\uc774\uae30 \uc704\ud574 GC\uc5d0 \ub300\ud574 \uc774\ud574<\/span>\ud574\uc57c\ud558\ub294 \uac83\uc774\ub2e4.<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong><span style=\"color: #3366ff;\">Serial GC<\/span><\/strong><br \/>\n-&gt;<span style=\"color: #3366ff;\"> \uc2f1\uae00 CPU<\/span>\uc758 \uacbd\uc6b0 \uc0ac\uc6a9, \uc131\ub2a5\uc774 \uc88b\uc9c0 \uc54a\uc74c. \uc2e4\uc81c \uc6b4\uc601\uc11c\ubc84\uc5d0\uc11c \uc0ac\uc6a9 X<br \/>\n-&gt; \ud074\ub77c\uc774\uc5b8\ud2b8 JIT\ucef4\ud30c\uc77c\ub7ec\uc758 \uacbd\uc6b0 Serial GC\ub97c \uc0ac\uc6a9<br \/>\n-&gt;Old \uc601\uc5ed\uc5d0 \ub300\ud574\uc11c\ub294 Mark-sweep-compact \uceec\ub809\uc158\uc744 \uc0ac\uc6a9(\uc0b4\uc544\uc788\ub294 \uac1d\uccb4\ub97c \ub9c8\ud06c-&gt; sweep-&gt;\ub0a8\uc740 \uac1d\uccb4\ub97c \uc55e\uc73c\ub85c \uc815\ub9ac)<br \/>\n<span style=\"color: #ffffff;\">&#8211;<\/span><\/li>\n<li><span style=\"color: #3366ff;\"><strong>Parallel GC<\/strong><\/span><br \/>\n-&gt; Serial GC\uc640 \uac19\uc740 \uc54c\uace0\ub9ac\uc998\uc774\uc9c0\ub9cc, <span style=\"color: #3366ff;\">GC\ub97c \uc704\ud55c \uc2a4\ub808\ub4dc\uac00 \uc5ec\ub7ec\uac1c<\/span><br \/>\n-&gt; Old\uc601\uc5ed\uc5d0 \ub300\ud574 Mark-sweep-compact \uceec\ub809\uc158\uc744 \uc0ac\uc6a9\ud55c\ub2e4\ub294 \uc810\uc740 serial\uacfc \uac19\uc74c<br \/>\n<span style=\"color: #ffffff;\">&#8211;<\/span><\/li>\n<li><strong><span style=\"color: #3366ff;\">Parallel Old GC(Parallel Compacting GC)<\/span><\/strong><br \/>\n-&gt; <span style=\"color: #000000;\">Old\uc601\uc5ed\uc5d0 \ub300\ud55c \uceec\ub809\uc158 \uc54c\uace0\ub9ac\uc998\uc774 Parallet GC\uc640 \ub2e4\ub984<\/span><br \/>\n<span style=\"color: #ffffff;\">&#8211;<\/span><\/li>\n<li><strong><span style=\"color: #3366ff;\">Concurrent Mark &amp; Sweep GC(\uc774\ud558 CMS)<\/span><\/strong><br \/>\n-&gt; \ud799 \uba54\ubaa8\ub9ac \uc601\uc5ed\uc774 \ud074 \uacbd\uc6b0 \uc801\ud569\ud55c GC<br \/>\n-&gt; Young\uc601\uc5ed\uc5d0 \ub300\ud55c \uceec\ub809\uc158\uc740 Parallel GC\uc640 \uac19\uc740 \uc54c\uace0\ub9ac\uc998\uc744 \uc0ac\uc6a9\ud558\uc9c0\ub9cc <span style=\"color: #3366ff;\">Old\uc601\uc5ed\uc5d0 \ub300\ud55c \uc54c\uace0\ub9ac\uc998\uc774 \ub2e4\ub984<\/span><br \/>\n-&gt; \uc7ac\ud45c\uc2dc \ub2e8\uacc4\uc640 \uc0dd\uc874\ud55c \uac1d\uccb4\ub97c \uc67c\ucabd\uc73c\ub85c \ubab0\uc544\ub123\ub294<span style=\"color: #3366ff;\">(\ucef4\ud329\ud2b8) \ub2e8\uacc4\uac00 \uc5c6\uc74c<\/span><br \/>\n-&gt; Parallel GC\uc5d0\uc11c \uc0ac\uc6a9\ub418\ub294 \uc54c\uace0\ub9ac\uc998\uc5d0 \ube44\ud574<span style=\"color: #3366ff;\"> Stop-the-world \uac00 \uc9e7\uac8c \ub450\ubc88 \ubc1c\uc0dd<\/span>\ud55c\ub2e4\ub294 \uc810\uc774 \ub2e4\ub984<br \/>\n<span style=\"color: #ffffff;\">&#8211;<\/span><\/li>\n<li>G1(Garbage First) GC<br \/>\n-&gt; \ub2e4\ub978 4\uac1c\uc758 \uceec\ub809\ud130\uc640 \uc880 \ub2e4\ub978\ud615\ud0dc, Young\uacfc Old\uc601\uc5ed\uc774 \ubb3c\ub9ac\uc801\uc73c\ub85c \ub098\ub220\uc838 \uc788\uc9c0\uc54a\uace0 \ud574\ub2f9 \uc601\uc5ed\uc758 \uac1d\uccb4\ub4e4\uc744 <span style=\"color: #3366ff;\">Region\uc774\ub77c\ub294 \uad6c\uc5ed<\/span>\uc5d0 \ud560\ub2f9\ud55c\ub2e4. \uc774 region\uc774\ub77c\ub294 \uad6c\uc5ed\uc774 Eden, Survivor, Old \uac19\uc740 \uc601\uc5ed\uc758 \uc5ed\ud65c\uc744 \ubc14\uafd4\uac00\uba70 \uc218\ud589\ud558\uac8c \ub41c\ub2e4.<br \/>\n-&gt; Old \uc601\uc5ed\uc758 GC\uc54c\uace0\ub9ac\uc998 \uacbd\uc6b0, CMS CG\uc640 \ube44\uc2b7\ud55c\ub370, \uc0b4\uc544 \uc788\ub294 \uac1d\uccb4 \uc5d0 \ub300\ud574 \ub9c8\uc9c0\ub9c9\uc5d0 \ubcf5\uc0ac\ub2e8\uacc4\ub97c \ud1b5\ud574 \ube44\uc5b4\uc788\ub294 \uad6c\uc5ed\uc73c\ub85c \uc774\ub3d9\uc2dc\ud0a4\ub294\uc810\uc774 \ucd94\uac00\uc801\uc73c\ub85c \ubc1c\uc0dd\ub41c\ub2e4.<br \/>\n-&gt;<span style=\"color: #3366ff;\"> CG \uc131\ub2a5\uc774 \uac00\uc7a5 \ube60\ub984(stop-the-world\uc758 \uc2dc\uac04\uc774 \uac00\uc7a5\uc9e7\uc74c)<\/span><\/li>\n<\/ul>\n<p>\ucc38\uace0 :\u00a0http:\/\/d2.naver.com\/helloworld\/1329, \uc790\ubc14\uc131\ub2a5\ud29c\ub2dd\uc774\uc57c\uae30(\uc774\uc0c1\ubbfc \uc9c0\uc74c)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\uc790\ubc14\ub294 \uac1c\ubc1c\uc790\uac00 \uba54\ubaa8\ub9ac\ub97c \uba85\uc2dc\uc801\uc73c\ub85c \ud574\uc9c0 \ud558\uc9c0 \uc54a\uace0 GC\uac00 \ub354 \uc774\uc0c1 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294 \uac1d\uccb4\uc5d0 \ub300\ud574 \uba54\ubaa8\ub9ac\ub97c \ud574\uc9c0 \ud558\ub294 \uc791\uc5c5\uc744 \uc9c4\ud589\ud55c\ub2e4. GC\uc5d0 \ub300\ud574 \uc774\ud574\ud558\uae30 \uc704\ud574\uc11c\ub294 \uc790\ubc14\uc758 \uba54\ubaa8\ub9ac&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[3],"tags":[19],"aioseo_notices":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"http:\/\/mukgee.com\/index.php?rest_route=\/wp\/v2\/posts\/286"}],"collection":[{"href":"http:\/\/mukgee.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/mukgee.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/mukgee.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/mukgee.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=286"}],"version-history":[{"count":0,"href":"http:\/\/mukgee.com\/index.php?rest_route=\/wp\/v2\/posts\/286\/revisions"}],"wp:attachment":[{"href":"http:\/\/mukgee.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=286"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/mukgee.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=286"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/mukgee.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=286"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}