1 /* 2 * Copyright (c) 2006, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * @test 26 * @bug 6396794 27 * @summary Check that LastGcInfo contents are reasonable 28 * @author Eamonn McManus 29 * 30 * @modules jdk.management 31 * 32 * @run main/othervm -XX:-ExplicitGCInvokesConcurrent GcInfoCompositeType 33 */ 34 // Passing "-XX:-ExplicitGCInvokesConcurrent" to force System.gc() 35 // run on foreground when CMS is used and prevent situations when "GcInfo" 36 // is missing even though System.gc() was successfuly processed. 37 38 import java.util.*; 39 import java.lang.management.*; 40 import java.lang.reflect.*; 41 import javax.management.*; 42 import javax.management.openmbean.*; 43 import com.sun.management.GcInfo; 44 45 public class GcInfoCompositeType { 46 private static int tested = 0; 47 48 public static void main(String[] args) throws Exception { 49 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); 50 final ObjectName gcMXBeanPattern = 51 new ObjectName("java.lang:type=GarbageCollector,*"); 52 Set<ObjectName> names = 53 mbs.queryNames(gcMXBeanPattern, null); 54 if (names.isEmpty()) 55 throw new Exception("Test incorrect: no GC MXBeans"); 56 System.gc(); 57 for (ObjectName n : names) 58 tested += test(mbs, n); 59 if (tested == 0) 60 throw new Exception("No MXBeans were tested"); 61 System.out.println("Test passed"); 62 } 63 64 private static int test(MBeanServer mbs, ObjectName n) throws Exception { 65 System.out.println("Testing " + n); 66 MBeanInfo mbi = mbs.getMBeanInfo(n); 67 MBeanAttributeInfo lastGcAI = null; 68 for (MBeanAttributeInfo mbai : mbi.getAttributes()) { 69 if (mbai.getName().equals("LastGcInfo")) { 70 lastGcAI = mbai; 71 break; 72 } 73 } 74 if (lastGcAI == null) 75 throw new Exception("No LastGcInfo attribute"); 76 CompositeType declaredType = 77 (CompositeType) lastGcAI.getDescriptor().getFieldValue("openType"); 78 checkType(declaredType); 79 CompositeData cd = 80 (CompositeData) mbs.getAttribute(n, "LastGcInfo"); 81 if (cd == null) { 82 System.out.println("Value of attribute null"); 83 return 0; 84 } else 85 return checkType(cd.getCompositeType()); 86 } 87 88 private static int checkType(CompositeType ct) throws Exception { 89 Method[] methods = GcInfo.class.getMethods(); 90 Set<String> getters = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER); 91 for (Method m : methods) { 92 if (m.getName().startsWith("get") && m.getParameterTypes().length == 0) 93 getters.add(m.getName().substring(3)); 94 } 95 Set<String> items = new HashSet<String>(ct.keySet()); 96 System.out.println("Items at start: " + items); 97 98 // Now check that all the getters have a corresponding item in the 99 // CompositeType, except the following: 100 // getClass() inherited from Object should not be an item; 101 // getCompositeType() inherited from CompositeData is not useful so 102 // our hack removes it too. 103 // Also track which items had corresponding getters, to make sure 104 // there is at least one item which does not (GcThreadCount or 105 // another gc-type-specific item). 106 final String[] surplus = {"Class", "CompositeType"}; 107 for (String key : ct.keySet()) { 108 if (getters.remove(key)) 109 items.remove(key); 110 } 111 if (!getters.equals(new HashSet<String>(Arrays.asList(surplus)))) { 112 throw new Exception("Wrong getters: " + getters); 113 } 114 if (items.isEmpty()) { 115 System.out.println("No type-specific items"); 116 return 0; 117 } else { 118 System.out.println("Type-specific items: " + items); 119 return 1; 120 } 121 } 122 }