1 /* 2 * Copyright (c) 2006, 2013 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 * @run main/othervm -XX:-ExplicitGCInvokesConcurrent GcInfoCompositeType 30 */ 31 // Passing "-XX:-ExplicitGCInvokesConcurrent" to force System.gc() 32 // run on foreground when CMS is used and prevent situations when "GcInfo" 33 // is missing even though System.gc() was successfuly processed. 34 35 import java.util.*; 36 import java.lang.management.*; 37 import java.lang.reflect.*; 38 import javax.management.*; 39 import javax.management.openmbean.*; 40 import com.sun.management.GcInfo; 41 42 public class GcInfoCompositeType { 43 private static int tested = 0; 44 45 public static void main(String[] args) throws Exception { 46 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); 47 final ObjectName gcMXBeanPattern = 48 new ObjectName("java.lang:type=GarbageCollector,*"); 49 Set<ObjectName> names = 50 mbs.queryNames(gcMXBeanPattern, null); 51 if (names.isEmpty()) 52 throw new Exception("Test incorrect: no GC MXBeans"); 53 System.gc(); 54 for (ObjectName n : names) 55 tested += test(mbs, n); 56 if (tested == 0) 57 throw new Exception("No MXBeans were tested"); 58 System.out.println("Test passed"); 59 } 60 61 private static int test(MBeanServer mbs, ObjectName n) throws Exception { 62 System.out.println("Testing " + n); 63 MBeanInfo mbi = mbs.getMBeanInfo(n); 64 MBeanAttributeInfo lastGcAI = null; 65 for (MBeanAttributeInfo mbai : mbi.getAttributes()) { 66 if (mbai.getName().equals("LastGcInfo")) { 67 lastGcAI = mbai; 68 break; 69 } 70 } 71 if (lastGcAI == null) 72 throw new Exception("No LastGcInfo attribute"); 73 CompositeType declaredType = 74 (CompositeType) lastGcAI.getDescriptor().getFieldValue("openType"); 75 checkType(declaredType); 76 CompositeData cd = 77 (CompositeData) mbs.getAttribute(n, "LastGcInfo"); 78 if (cd == null) { 79 System.out.println("Value of attribute null"); 80 return 0; 81 } else 82 return checkType(cd.getCompositeType()); 83 } 84 85 private static int checkType(CompositeType ct) throws Exception { 86 Method[] methods = GcInfo.class.getMethods(); 87 Set<String> getters = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER); 88 for (Method m : methods) { 89 if (m.getName().startsWith("get") && m.getParameterTypes().length == 0) 90 getters.add(m.getName().substring(3)); 91 } 92 Set<String> items = new HashSet<String>(ct.keySet()); 93 System.out.println("Items at start: " + items); 94 95 // Now check that all the getters have a corresponding item in the 96 // CompositeType, except the following: 97 // getClass() inherited from Object should not be an item; 98 // getCompositeType() inherited from CompositeData is not useful so 99 // our hack removes it too. 100 // Also track which items had corresponding getters, to make sure 101 // there is at least one item which does not (GcThreadCount or 102 // another gc-type-specific item). 103 final String[] surplus = {"Class", "CompositeType"}; 104 for (String key : ct.keySet()) { 105 if (getters.remove(key)) 106 items.remove(key); 107 } 108 if (!getters.equals(new HashSet<String>(Arrays.asList(surplus)))) { 109 throw new Exception("Wrong getters: " + getters); 110 } 111 if (items.isEmpty()) { 112 System.out.println("No type-specific items"); 113 return 0; 114 } else { 115 System.out.println("Type-specific items: " + items); 116 return 1; 117 } 118 } 119 }