{"id":44634,"date":"2020-12-14T21:30:27","date_gmt":"2020-12-14T12:30:27","guid":{"rendered":"https:\/\/www.charlezz.com\/?p=44634"},"modified":"2021-05-06T10:13:29","modified_gmt":"2021-05-06T01:13:29","slug":"%ec%bd%94%eb%a3%a8%ed%8b%b4%ec%9d%b4-%ea%b2%bd%eb%9f%89-%ec%8a%a4%eb%a0%88%eb%93%9c%ec%9d%b8-%ec%9d%b4%ec%9c%a0-light-weight-thread","status":"publish","type":"post","link":"https:\/\/charlezz.com\/?p=44634","title":{"rendered":"\ucf54\ub8e8\ud2f4\uc774 \uacbd\ub7c9 \uc2a4\ub808\ub4dc\uc778 \uc774\uc720 (Light-weight thread)"},"content":{"rendered":"<h1>Why Coroutine is light-weight thread<\/h1>\n<p><a href=\"https:\/\/www.charlezz.com\/wordpress\/wp-content\/uploads\/2020\/12\/www.charlezz.com-light-weight-thread-screenshot.png\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.charlezz.com\/wordpress\/wp-content\/uploads\/2020\/12\/www.charlezz.com-light-weight-thread-screenshot.png\" alt=\"\" width=\"880\" height=\"618\" class=\"aligncenter size-full wp-image-44644\" srcset=\"https:\/\/charlezz.com\/wordpress\/wp-content\/uploads\/2020\/12\/www.charlezz.com-light-weight-thread-screenshot.png 880w, https:\/\/charlezz.com\/wordpress\/wp-content\/uploads\/2020\/12\/www.charlezz.com-light-weight-thread-screenshot-300x211.png 300w, https:\/\/charlezz.com\/wordpress\/wp-content\/uploads\/2020\/12\/www.charlezz.com-light-weight-thread-screenshot-768x539.png 768w\" sizes=\"(max-width: 880px) 100vw, 880px\" \/><\/a><\/p>\n<p>\ucf54\ud2c0\ub9b0 <a href=\"https:\/\/kotlinlang.org\/docs\/reference\/coroutines\/basics.html#coroutines-are-light-weight\">\uacf5\uc2dd \ubb38\uc11c<\/a>\uc5d0\uc11c\ub294 \ucf54\ub8e8\ud2f4\uc744 \uacbd\ub7c9 \uc2a4\ub808\ub4dc(light-weight thread)\ub77c\uace0 \ud45c\ud604\ud558\uace0 \uc788\ub294\ub370, \uadf8 \uc774\uc720\ub97c \uc54c\uc544\ubcf4\uc790.<\/p>\n<p>\ucf54\ub8e8\ud2f4\uc740 \uc2a4\ub808\ub4dc\uc5d0\uc11c \uc2e4\ud589\ub41c\ub2e4. \uc774\uac83\uc740 \ub300\uc6d0\uce59\uc774\ub2e4. \ucf54\ub8e8\ud2f4\uc774 \ub2e8\ub3c5\uc73c\ub85c \ub610\ub294 \ub2e4\ub978 \uc218\ub2e8\uc5d0 \uc758\ud574 \uc2e4\ud589\ub420 \uc218 \uc5c6\ub2e4\ub294 \uac83\uc744 \uba85\uc2ec\ud558\uc790. \uadf8\ub9ac\uace0 \uc5ec\ub7ec\uac1c\uc758 \ucf54\ub8e8\ud2f4\uc744 \ud558\ub098\uc758 \uc2a4\ub808\ub4dc\ub97c \uc9c0\uc815\ud558\uc5ec \uc2e4\ud589\ud560 \uc218 \uc788\uc9c0\ub9cc \ub3d9\uc2dc\uc5d0 \uc2e4\ud589 \ud558\ub294 \uac83\uc740 \ubd88\uac00\ub2a5\ud558\uace0, \ud55c\ubc88\uc5d0 \ud558\ub098\uc758 \uba85\ub839\uc5b4\ub9cc \uc2e4\ud589\ud560 \uc218 \uc788\ub2e4. \uadf8 \uc774\uc720\ub294 \ucf54\ub8e8\ud2f4\uc740 \uc2a4\ub808\ub4dc\ub0b4\uc5d0\uc11c \uc2e4\ud589\ub418\uace0 \uc911\ub2e8 \uc9c0\uc810(suspension point)\uc5d0 \ub3c4\ub2ec\ud558\uc790\ub9c8\uc790 \uc2a4\ub808\ub4dc\ub97c \ub5a0\ub098 \ub300\uae30\uc911\uc778 \ub2e4\ub978 \ucf54\ub8e8\ud2f4\uc744 \uc120\ud0dd\ud560 \uc218 \uc788\ub3c4\ub85d \ud574\ubc29\ud558\uae30 \ub54c\ubb38\uc774\ub2e4. \uc774\ub807\uac8c\ud558\uba74 \uc2a4\ub808\ub4dc\uc640 <strong>\uba54\ubaa8\ub9ac \uc0ac\uc6a9\ub7c9\uc774 \uc904\uc5b4\ub4e4\uc5b4 \ub9ce\uc740 \ub3d9\uc2dc\uc131 \uc791\uc5c5\uc744 \uc218\ud589<\/strong>\ud560 \uc218 \uc788\uac8c \ub41c\ub2e4.<\/p>\n<p>\uc880 \ub354 \ub0ae\uc740 \uad00\uc810\uc5d0\uc11c \uc0b4\ud3b4\ubcf4\uba74 \ucf54\ud2c0\ub9b0\uc758 \ucf54\ub8e8\ud2f4\uc740 <a href=\"https:\/\/www.charlezz.com\/?p=44635\">\uc2a4\ud0dd\ub9ac\uc2a4 \ucf54\ub8e8\ud2f4(Stackless Coroutine)<\/a>\uc774\ub2e4. \uc2a4\ud0dd\ub9ac\uc2a4 \ucf54\ub8e8\ud2f4\uc740 \uc2a4\ud0dd\uc774 \uc5c6\ub2e4\ub294 \uc758\ubbf8\ub2e4. \ub610\ud55c \ud2b9\uc815 \uc2a4\ub808\ub4dc\uc5d0 \uc885\uc18d\ub418\uc9c0\ub3c4 \uc54a\ub294\ub2e4. \uadf8\ub807\uae30 \ub54c\ubb38\uc5d0 \ud504\ub85c\uc138\uc11c\uc5d0\uc11c Context Switching\uc774 \ud544\uc694\ud558\uc9c0 \uc54a\ub2e4. \uc774\ub7ec\ud55c \uc774\uc720\ub4e4\ub85c \uc778\ud574 \uc218\ucc9c\uac1c\uc758 \uc2a4\ub808\ub4dc\ub97c \uc0dd\uc131\ud558\ub294 \uac83\ubcf4\ub2e4 \uc218\ucc9c\uac1c\uc758 \ucf54\ub8e8\ud2f4\uc744 \uc0dd\uc131\ud558\ub294 \uac83\uc774 \ub354 \ube60\ub974\uace0, \uc790\uc6d0\uc744 \uc801\uac8c \uc0ac\uc6a9\ud55c\ub2e4.\u00a0<\/p>\n<p>\ub2e4\uc74c \ucf54\ub4dc\ub97c \ud1b5\ud574 \ucf54\ub8e8\ud2f4\uc758 \ubb34\uac8c\uac10\uc744 \ub290\uaef4\ubcf4\uc790<\/p>\n<pre class=\"lang:null decode:true lang:\">@Test\r\nfun coroutineTest() {\r\n    runBlocking {\r\n        println(\"\uc2dc\uc791::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = ${Thread.activeCount()}\")\r\n        val time = measureTimeMillis {\r\n            val jobs = ArrayList&lt;Job&gt;()\r\n            repeat(10000) {\r\n                jobs += launch(Dispatchers.Default) {\r\n                    delay(1000L)\r\n                }\r\n            }\r\n            println(\"\ub05d::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = ${Thread.activeCount()}\")\r\n            jobs.forEach { it.join() }\r\n        }\r\n        println(\"Took $time ms\")\r\n    }\r\n}<\/pre>\n<p><strong>\uc2e4\ud589\uacb0\uacfc:<br \/>\n<\/strong>\uc2dc\uc791::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = 2<br \/>\n\ub05d::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = 11<br \/>\nTook 1131 ms<\/p>\n<p><em><strong>Note : measureTimeMillis\ub294 \ucf54\ub4dc \ube14\ub7ed\uc744 \uac16\ub294 \uc778\ub77c\uc778 \ud568\uc218\ub85c\uc368 \uc2e4\ud589\uc2dc\uac04(ms)\uc744 \ubc18\ud658\ud55c\ub2e4.<\/strong><\/em><\/p>\n<p>coroutineTest\uc758 launch {&#8230;} \ubd80\ubd84\uc744 \ucf54\ub8e8\ud2f4 \ub300\uc2e0 \uc2a4\ub808\ub4dc\ub97c \uc0ac\uc6a9\ud558\ub294 \ucf54\ub4dc\ub85c \ub300\uccb4\ud574\ubcf4\uc790.<\/p>\n<pre class=\"lang:null decode:true lang:\">@Test\r\nfun threadTest() {\r\n    runBlocking {\r\n        println(\"\uc2dc\uc791::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = ${Thread.activeCount()}\")\r\n        val time = measureTimeMillis {\r\n            val jobs = ArrayList&lt;Thread&gt;()\r\n            repeat(10000) {\r\n                jobs += Thread {\r\n                    Thread.sleep(1000L)\r\n                }.also { it.start() }\r\n            }\r\n            println(\"\ub05d::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = ${Thread.activeCount()}\")\r\n            jobs.forEach { it.join() }\r\n        }\r\n        println(\"Took $time ms\")\r\n    }\r\n}<\/pre>\n<p><strong>\uc2e4\ud589\uacb0\uacfc:<\/strong><br \/>\n\uc2dc\uc791::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = 2<br \/>\n\ub05d::\ud65c\uc131\ud654 \ub41c \uc2a4\ub808\ub4dc \uac2f\uc218 = 2282<br \/>\nTook 4123 ms<br \/>\n\ub2e8\uc21c \uc218\uce58\uc0c1\uc73c\ub85c\ub294 \ucf54\ub8e8\ud2f4\uc774 \uc57d 4\ubc30\uc815\ub3c4 \ube60\ub978 \ubaa8\uc2b5\uc744 \ubcf4\uc5ec\uc900\ub2e4. \uc544\ubb34\ub798\ub3c4 threadTest() \ud568\uc218\uc758 \uacbd\uc6b0 \uc2a4\ub808\ub4dc\ub97c \uc0dd\uc131\ud558\ub294 \uacfc\uc815\uc5d0\uc11c \uba54\ubaa8\ub9ac\ub97c \ud560\ub2f9\ud558\uace0 \ud574\uc81c\ud558\ub294 \ubd80\ubd84\uc758 \ube44\uc6a9\uc774 \ub9ce\uc774 \ub4e4\uae30 \ub54c\ubb38\uc77c \uac83\uc774\ub2e4.<\/p>\n<p>\ub610\ud55c \ud65c\uc131\ud654\ub41c \uc2a4\ub808\ub4dc \uce74\uc6b4\ud2b8\uc758 \uac2f\uc218\ub97c \ubcf4\uba74 coroutineTest()\ub294 \ub2e8 \ub450\uac1c\uc758 \uc2a4\ub808\ub4dc\ub9cc \ud65c\uc131\ud654 \ub418\uc5b4\uc788\uc9c0\ub9cc, threadTest()\ub294 2282\uac1c\uc758 \uc2a4\ub808\ub4dc\uac00 \ud65c\uc131\ud654 \ub41c \uac83\uc744 \ud655\uc778\ud560 \uc218 \uc788\ub2e4.<\/p>\n<p>\ub9cc\uc57d \uba54\ubaa8\ub9ac\uac00 \uc791\uc740 \ud658\uacbd\uc774\ub77c\uba74 \uc2a4\ub808\ub4dc\ub97c \uc0dd\uc131\ud558\ub2e4\uac00 \ub2e4\uc74c\uacfc \uac19\uc740 OOM \uc5d0\ub7ec\uac00 \ubc1c\uc0dd\ud560 \uc218\ub3c4 \uc788\uc5c8\ub2e4.<br \/>\n[java.lang.OutOfMemoryError: unable to create new native thread]<\/p>\n<p>\uc784\uc758\ub85c OOM\uc744 \ubc1c\uc0dd\uc2dc\ud0a4\ub294 \ud14c\uc2a4\ud2b8\ub97c \uc6d0\ud55c\ub2e4\uba74 repeat \uce74\uc6b4\ud2b8\ub97c 100000\uc774\uc0c1, \uc2a4\ub808\ub4dc\uc758 sleep \uc2dc\uac04\uc744 100000\uc774\uc0c1\uc73c\ub85c\u00a0 \ubcc0\uacbd\ud574\ubcf4\uc790.<\/p>\n<p>\ud55c\uac00\uc9c0 \ub354 \ud14c\uc2a4\ud2b8\ub97c \ud574\ubcf4\uc790. \ucf54\ub8e8\ud2f4\uc740 \ud2b9\uc815 \uc2a4\ub808\ub4dc\uc5d0 \ub9e4\ud551\ub418\uc9c0 \uc54a\ub294\ub370, \uc704\uc758 \uc608\uc81c\ub97c \uc774\uc6a9\ud558\uc5ec \uc774 \uc810\uc744 \uc2e4\ud5d8\ud574\ubcf4\uc790.<\/p>\n<pre class=\"lang: decode:true \">@Test\r\nfun coroutineTest() {\r\n    runBlocking{\r\n        val time = measureTimeMillis {\r\n            val jobs = ArrayList&lt;Job&gt;()\r\n            for(i in 1..3) {\r\n                jobs += launch(Dispatchers.Default) {\r\n                    println(\"Start #$i::${Thread.currentThread().name}\")\r\n                    delay(1000L)\r\n                    println(\"End   #$i::${Thread.currentThread().name}\")\r\n                }\r\n            }\r\n            jobs.forEach { it.join() }\r\n        }\r\n        println(\"Took $time ms\")\r\n    }\r\n}<\/pre>\n<p>\ucf54\ub4dc\ub97c \uc0b4\uc9dd \uace0\ucce4\ub2e4. repeat()\ub97c for\ubb38\uc73c\ub85c \ubcc0\uacbd\ud558\uc5ec 3\ubc88\ub9cc \ubc18\ubcf5\ud558\ub3c4\ub85d \ud588\uace0, delay\ub97c \ud638\ucd9c\ud558\uae30 \uc804\uacfc \ud6c4\ub85c \uc2a4\ub808\ub4dc\uc758 \uc774\ub984\uc774 \uc5b4\ub5bb\uac8c \ub2e4\ub978\uc9c0 \uc54c\uc544\ubcf4\uae30 \uc704\ud574 \uba54\uc2dc\uc9c0\ub97c \ucd9c\ub825\ud55c\ub2e4.<\/p>\n<p><strong>\uc2e4\ud589 \uacb0\uacfc:<br \/>\n<\/strong>Start #1::DefaultDispatcher-worker-1 @coroutine#2<br \/>\nStart #2::DefaultDispatcher-worker-2 @coroutine#3<br \/>\nStart #3::DefaultDispatcher-worker-3 @coroutine#4<br \/>\nEnd\u00a0 \u00a0#2::DefaultDispatcher-worker-2 @coroutine#3<br \/>\nEnd\u00a0 \u00a0#3::DefaultDispatcher-worker-1 @coroutine#4<br \/>\nEnd\u00a0 \u00a0#1::DefaultDispatcher-worker-3 @coroutine#2<br \/>\nTook 1015 ms<\/p>\n<p>delay() \ud568\uc218 \ud638\ucd9c\ud6c4 \ub2e4\ub978 \uc2a4\ub808\ub4dc\uc5d0\uc11c \ub2e4\uc2dc \uc2dc\uc791\ud558\ub294 \uacbd\uc6b0\ub97c \ud655\uc778\ud560 \uc218 \uc788\ub2e4.<\/p>\n<p>\uc2a4\ub808\ub4dc\ub294 \ud55c \ubc88\uc5d0 \ud558\ub098\uc758 \ucf54\ub8e8\ud2f4\ub9cc \uc2e4\ud589\ud560 \uc218 \uc788\uae30 \ub54c\ubb38\uc5d0, \uc2dc\uc2a4\ud15c \ud544\uc694\uc5d0 \ub530\ub77c \ucf54\ub8e8\ud2f4\uc744 \uc2a4\ub808\ub4dc\ub4e4 \uc0ac\uc774\uc5d0\uc11c \uc62e\uae30\uac8c \ub41c\ub2e4.\u00a0<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Why Coroutine is light-weight thread \ucf54\ud2c0\ub9b0 \uacf5\uc2dd \ubb38\uc11c\uc5d0\uc11c\ub294 \ucf54\ub8e8\ud2f4\uc744 \uacbd\ub7c9 \uc2a4\ub808\ub4dc(light-weight thread)\ub77c\uace0 \ud45c\ud604\ud558\uace0 \uc788\ub294\ub370, \uadf8 \uc774\uc720\ub97c \uc54c\uc544\ubcf4\uc790. \ucf54\ub8e8\ud2f4\uc740 \uc2a4\ub808\ub4dc\uc5d0\uc11c \uc2e4\ud589\ub41c\ub2e4. \uc774\uac83\uc740 \ub300\uc6d0\uce59\uc774\ub2e4. \ucf54\ub8e8\ud2f4\uc774 \ub2e8\ub3c5\uc73c\ub85c \ub610\ub294 \ub2e4\ub978 \uc218\ub2e8\uc5d0 \uc758\ud574 \uc2e4\ud589\ub420 \uc218 \uc5c6\ub2e4\ub294 \uac83\uc744 \uba85\uc2ec\ud558\uc790. \uadf8\ub9ac\uace0 \uc5ec\ub7ec\uac1c\uc758 \ucf54\ub8e8\ud2f4\uc744 \ud558\ub098\uc758 \uc2a4\ub808\ub4dc\ub97c \uc9c0\uc815\ud558\uc5ec \uc2e4\ud589\ud560 \uc218 \uc788\uc9c0\ub9cc \ub3d9\uc2dc\uc5d0 \uc2e4\ud589 \ud558\ub294 \uac83\uc740 \ubd88\uac00\ub2a5\ud558\uace0, \ud55c\ubc88\uc5d0 \ud558\ub098\uc758 \uba85\ub839\uc5b4\ub9cc [&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,"inline_featured_image":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"categories":[5],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/charlezz.com\/index.php?rest_route=\/wp\/v2\/posts\/44634"}],"collection":[{"href":"https:\/\/charlezz.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/charlezz.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/charlezz.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/charlezz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=44634"}],"version-history":[{"count":3,"href":"https:\/\/charlezz.com\/index.php?rest_route=\/wp\/v2\/posts\/44634\/revisions"}],"predecessor-version":[{"id":45063,"href":"https:\/\/charlezz.com\/index.php?rest_route=\/wp\/v2\/posts\/44634\/revisions\/45063"}],"wp:attachment":[{"href":"https:\/\/charlezz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=44634"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/charlezz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=44634"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/charlezz.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=44634"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}