\r\npackage jp.yucchi.softreference_g1gc;\r\n\r\nimport java.lang.management.ManagementFactory;\r\nimport java.lang.ref.Reference;\r\nimport java.lang.ref.ReferenceQueue;\r\nimport java.lang.ref.SoftReference;\r\nimport java.util.ArrayList;\r\nimport java.util.List;\r\n\r\n\/**\r\n *\r\n * @author Yucchi\r\n *\/\r\npublic class SoftReference_G1GC {\r\n\r\n private static final ReferenceQueue<MemoryConsumer> REFEREN_CEQUEU = new ReferenceQueue<>();\r\n\r\n public static void main(String[] args) {\r\n\r\n System.out.println(System.getProperty(\"os.name\") + \" \"\r\n + System.getProperty(\"os.version\") + \" \" + System.getProperty(\"os.arch\"));\r\n System.out.println(\"JDK \" + System.getProperty(\"java.version\") + System.lineSeparator());\r\n\r\n List<SoftReference<MemoryConsumer>> list = new ArrayList<>();\r\n\r\n for (int i = 0; i < 1_000; i++) {\r\n var memoryConsumer = new MemoryConsumer();\r\n var softReference = new SoftReference<>(memoryConsumer, REFEREN_CEQUEU);\r\n list.add(softReference);\r\n checkStatus();\r\n }\r\n\r\n }\r\n\r\n private static void checkStatus() {\r\n\r\n var memoryBean = ManagementFactory.getMemoryMXBean();\r\n var usage = memoryBean.getHeapMemoryUsage();\r\n var usedMemory = usage.getUsed();\r\n var gcMXBeans = ManagementFactory.getGarbageCollectorMXBeans();\r\n var gcStatus = new StringBuilder();\r\n gcMXBeans.forEach(e -> {\r\n gcStatus\r\n .append(e.getName())\r\n .append(\" \")\r\n .append(\"GC Count: \")\r\n .append(e.getCollectionCount())\r\n .append(\" \")\r\n .append(\"GCTime = \")\r\n .append(e.getCollectionTime())\r\n .append(\" \");\r\n });\r\n\r\n System.out.print(\"UsedMemory: \" + usedMemory + \" \");\r\n System.out.println(gcStatus);\r\n\r\n Reference<?> ref;\r\n while ((ref = REFEREN_CEQUEU.poll()) != null) {\r\n System.out.println(\" --- POLL:\" + ref + \" ---\");\r\n }\r\n\r\n }\r\n\r\n private static class MemoryConsumer {\r\n\r\n private final byte[] buff;\r\n\r\n MemoryConsumer() {\r\n this.buff = new byte[100 * 1024 * 1024];\r\n }\r\n\r\n }\r\n\r\n}\r\n\r\n<\/code><\/pre>\n <\/p>\n \u7121\u99c4\u306b\u30e1\u30e2\u30ea\u30fc\u3092\u6d88\u8cbb\u3059\u308b\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u30921000\u500b\u4f5c\u3063\u3066\u3044\u308b\u3060\u3051\u3067\u3059\u3002<\/p>\n \u666e\u901a\u306a\u3089 OutOfMemoryError \u3067\u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u6b62\u307e\u3063\u3066\u3057\u307e\u3046\u306f\u305a\u3067\u3059\u304c SoftReference \u3092\u4f7f\u3063\u3066\u8ce2\u3044\u30ac\u30d9\u30fc\u30b8\u30fb\u30b3\u30ec\u30af\u30bf\u306e\u529b\u3067\u5b8c\u8d70\u3055\u305b\u3088\u3046\u3068\u3044\u3046\u3082\u306e\u3067\u3059\u3002<\/p>\n \u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u7d50\u679c\u306f\u6b21\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n Windows 10 10.0 amd64 JDK 11.0.1<\/p>\n UsedMemory: 113246208 G1 Young Generation GC Count: 0 GCTime = 0 G1 Old Generation GC Count: 0 GCTime = 0 UsedMemory: 222298112 G1 Young Generation GC Count: 0 GCTime = 0 G1 Old Generation GC Count: 0 GCTime = 0 UsedMemory: 331350016 G1 Young Generation GC Count: 0 GCTime = 0 G1 Old Generation GC Count: 0 GCTime = 0 UsedMemory: 440401920 G1 Young Generation GC Count: 0 GCTime = 0 G1 Old Generation GC Count: 0 GCTime = 0 UsedMemory: 546493104 G1 Young Generation GC Count: 1 GCTime = 3 G1 Old Generation GC Count: 0 GCTime = 0 \u7565 UsedMemory: 110148312 G1 Young Generation GC Count: 57 GCTime = 109 G1 Old Generation GC Count: 2 GCTime = 1808 — POLL:java.lang.ref.SoftReference@59fa1d9b — — POLL:java.lang.ref.SoftReference@28d25987 — \u7565 — POLL:java.lang.ref.SoftReference@527740a2 — — POLL:java.lang.ref.SoftReference@13a5fe33 — UsedMemory: 219243560 G1 Young Generation GC Count: 58 GCTime = 110 G1 Old Generation GC Count: 2 GCTime = 1808 UsedMemory: 328295464 G1 Young Generation GC Count: 58 GCTime = 110 G1 Old Generation GC Count: 2 GCTime = 1808 \u7565 UsedMemory: 6762364184 G1 Young Generation GC Count: 222 GCTime = 332 G1 Old Generation GC Count: 12 GCTime = 8964 UsedMemory: 6871416088 G1 Young Generation GC Count: 222 GCTime = 332 G1 Old Generation GC Count: 12 GCTime = 8964 <\/p>\n \u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u7d42\u4e86\u3059\u308b\u307e\u3067\uff11\u5206\uff18\u79d2\u3082\u304b\u304b\u3063\u305f\u3002<\/p>\n \u79c1\u306e\uff17\u5e74\u524d\u306e\u30d1\u30bd\u30b3\u30f3\u304c\u58ca\u308c\u305f\u306e\u304b\u3068\u601d\u3063\u3066\u3057\u307e\u3063\u305f\u3002(^_^;)<\/font><\/strong><\/p>\n NetBeans \u306e\u30d7\u30ed\u30d5\u30a1\u30a4\u30e9\u3067\u3069\u3093\u306a\u304b\u3093\u3058\u306a\u306e\u304b\u78ba\u8a8d\u3057\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n <\/a><\/p>\n <\/p>\n <\/a><\/p>\n <\/p>\n <\/a><\/p>\n <\/p>\n \u78ba\u304b\u306b OutOfMemoryError \u3067\u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u6b62\u307e\u3089\u306a\u3044\u3088\u3046\u306b\u30ac\u30d9\u30fc\u30b8\u30fb\u30b3\u30ec\u30af\u30bf\u304c\u9811\u5f35\u3063\u3066\u3044\u308b\u3088\u3046\u3060\u3051\u3069GC\u6642\u9593\u9577\u304f\u306a\u3044\uff1f<\/p>\n \u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u7d50\u679c\u304b\u3089\u3082\u6c17\u306e\u305b\u3044\u304b GC \u306e\u56de\u6570\u3001\u7d2f\u7a4d\u6642\u9593\u304c\u9577\u3044\u3088\u3046\u306a\u6c17\u304c\u3059\u308b\u3002<\/p>\n SoftReference \u3063\u3066\u3053\u3093\u306a\u3082\u306e\u306a\u306e\u304b\u306a\u3041\u30fb\u30fb\u30fb<\/p>\n \u3042\u3063\u3001\u306a\u306b\u304b\u30d7\u30ed\u30b0\u30e9\u30e0\u306b\u554f\u984c\u304c\u3042\u308b\u306e\u304b\u3082\u3057\u308c\u306a\u3044\u3002<\/p>\n \u3053\u308c\u306f WeakReference \u3067\u8a66\u3057\u3066\u6bd4\u8f03\u3057\u3066\u307f\u308b\u3057\u304b\u306a\u3044\u3002<\/p>\n \u3068\u3044\u3046\u3053\u3068\u3067\u6b21\u56de\u306b\u7d9a\u304f<\/p>\n Hatena \u30bf\u30b0: Java<\/a>,NetBeans<\/a><\/div>\n\n <\/a><\/div>\n <\/a><\/div>\n <\/g:plusone><\/div>\n Tweet<\/a><\/div>\n <\/div>\n \n","protected":false},"excerpt":{"rendered":"\u3042\u3051\u307e\u3057\u3066\u304a\u3081\u3067\u3068\u3046\u3054\u3056\u3044\u307e\u3059\u3002 \u3068\u3046\u3068\u3046\u4eca\u5e74\u306e\uff15\u6708\u3067\u5e73\u6210\u304c\u7d42\u308f\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u3002 \u65b0\u3057\u3044\u5143\u53f7\u304c\u307e\u3060\u767a\u8868\u3055\u308c\u3066\u306a\u3044\u306e\u3067\u4e00\u90e8\u306e\u4eba\u306f\u56f0\u3063\u3066\u3044\u308b\u3088\u3046\u3067\u3059\u304c\u3069\u3046\u306b\u304b\u306a\u3089\u306a\u3044\u3082\u306e\u306a\u3093\u3067\u3057\u3087\u3046\u304b\uff1f \u3055\u3066\u3001\u3069\u3046\u306b\u3082\u306a\u3089\u306a\u3044\u3053\u3068\u3092\u3069\u3046\u304b\u3057\u3088\u3046\u3068\u3059\u308b\u3068\u982d\u304c\u75db\u304f\u306a\u308b\u304b\u3089\u73fe\u5b9f\u9003\u907f\u306e\u305f\u3081\u306b Java \u3067\u904a\u3076\u3068\u3057\u3088\u3046\u3002 SoftReference \u3063\u3066\u805e\u3044\u305f\u3053\u3068\u306f\u3042\u308b\u3051\u3069\u5b9f\u969b\u306b\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u7d44\u3080\u4e0a\u3067\u4f7f\u3063\u305f\u8a18\u61b6\u304c\u306a\u3044\u306e\u3067\u3053\u308c\u3067\u904a\u3093\u3067\u307f\u3088\u3046\u3002 java.base \u30e2\u30b8\u30e5\u30fc\u30eb\u306e java.lang.ref \u30d1\u30c3\u30b1\u30fc\u30b8\u306b\u3042\u308b public class SoftReference<T> extends Reference\u2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,4],"tags":[17,19],"class_list":["post-2675","post","type-post","status-publish","format-standard","hentry","category-java","category-netbeans","tag-java","tag-netbeans"],"_links":{"self":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2675","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2675"}],"version-history":[{"count":1,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2675\/revisions"}],"predecessor-version":[{"id":2676,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2675\/revisions\/2676"}],"wp:attachment":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2675"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2675"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2675"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}