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| 1 | +/* |
| 2 | + * Copyright IBM Corp. and others 2024 |
| 3 | + * |
| 4 | + * This program and the accompanying materials are made available under |
| 5 | + * the terms of the Eclipse Public License 2.0 which accompanies this |
| 6 | + * distribution and is available at https://www.eclipse.org/legal/epl-2.0/ |
| 7 | + * or the Apache License, Version 2.0 which accompanies this distribution and |
| 8 | + * is available at https://www.apache.org/licenses/LICENSE-2.0. |
| 9 | + * |
| 10 | + * This Source Code may also be made available under the following |
| 11 | + * Secondary Licenses when the conditions for such availability set |
| 12 | + * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU |
| 13 | + * General Public License, version 2 with the GNU Classpath |
| 14 | + * Exception [1] and GNU General Public License, version 2 with the |
| 15 | + * OpenJDK Assembly Exception [2]. |
| 16 | + * |
| 17 | + * [1] https://www.gnu.org/software/classpath/license.html |
| 18 | + * [2] https://openjdk.org/legal/assembly-exception.html |
| 19 | + * |
| 20 | + * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0 |
| 21 | + */ |
| 22 | +package com.ibm.j9ddr.vm29.tools.ddrinteractive.commands; |
| 23 | + |
| 24 | +import java.io.PrintStream; |
| 25 | + |
| 26 | +import com.ibm.j9ddr.CorruptDataException; |
| 27 | +import com.ibm.j9ddr.tools.ddrinteractive.Command; |
| 28 | +import com.ibm.j9ddr.tools.ddrinteractive.CommandUtils; |
| 29 | +import com.ibm.j9ddr.tools.ddrinteractive.Context; |
| 30 | +import com.ibm.j9ddr.tools.ddrinteractive.DDRInteractiveCommandException; |
| 31 | +import com.ibm.j9ddr.tools.ddrinteractive.Table; |
| 32 | +import com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer; |
| 33 | +import com.ibm.j9ddr.vm29.pointer.generated.J9ObjectPointer; |
| 34 | +import com.ibm.j9ddr.vm29.pointer.helper.J9ClassHelper; |
| 35 | +import com.ibm.j9ddr.vm29.pointer.helper.J9ObjectHelper; |
| 36 | + |
| 37 | +import com.ibm.j9ddr.vm29.j9.DataType; |
| 38 | +import com.ibm.j9ddr.vm29.j9.walkers.ClassSegmentIterator; |
| 39 | +import com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer; |
| 40 | +import com.ibm.j9ddr.vm29.pointer.generated.J9JavaVMPointer; |
| 41 | +import com.ibm.j9ddr.vm29.pointer.helper.J9RASHelper; |
| 42 | + |
| 43 | +import com.ibm.j9ddr.vm29.j9.gc.GCHeapRegionDescriptor; |
| 44 | +import com.ibm.j9ddr.vm29.j9.gc.GCHeapRegionIterator; |
| 45 | +import com.ibm.j9ddr.vm29.j9.gc.GCObjectHeapIterator; |
| 46 | + |
| 47 | +public class FindInstances extends Command |
| 48 | +{ |
| 49 | + private String className; |
| 50 | + private J9ClassPointer classPointer; |
| 51 | + private Table data; |
| 52 | + private long corruptCount; |
| 53 | + private long objectsFound; |
| 54 | + |
| 55 | + public FindInstances() { |
| 56 | + addCommand("findinstances", "<classname>", "find all instances of the specific class and its subclasses"); |
| 57 | + } |
| 58 | + |
| 59 | + private static void printUsage (PrintStream out) { |
| 60 | + out.println("findinstances <name> - find all instances of the specific class and its subclasses"); |
| 61 | + } |
| 62 | + |
| 63 | + private boolean parseArgs(PrintStream out, String[] args) throws DDRInteractiveCommandException { |
| 64 | + if (args.length != 1) { |
| 65 | + out.println("Exactly one argument expected"); |
| 66 | + return false; |
| 67 | + } |
| 68 | + String firstArg = args[0]; |
| 69 | + if (firstArg.equals("help")) { |
| 70 | + printUsage(out); |
| 71 | + return false; |
| 72 | + } |
| 73 | + className = firstArg; |
| 74 | + return true; |
| 75 | + } |
| 76 | + |
| 77 | + @Override |
| 78 | + public void run(String command, String[] args, Context context, PrintStream out) throws DDRInteractiveCommandException { |
| 79 | + if (args != null) { |
| 80 | + if (!parseArgs(out, args)) { |
| 81 | + return; |
| 82 | + } |
| 83 | + } |
| 84 | + |
| 85 | + try { |
| 86 | + J9JavaVMPointer vm = J9RASHelper.getVM(DataType.getJ9RASPointer()); |
| 87 | + ClassSegmentIterator iterator = new ClassSegmentIterator(vm.classMemorySegments()); |
| 88 | + |
| 89 | + out.format( |
| 90 | + "Searching for class named '%s' in VM=%s%n", |
| 91 | + className, Long.toHexString(vm.getAddress())); |
| 92 | + |
| 93 | + /* Reset classPointer for each invocation of the command. */ |
| 94 | + classPointer = null; |
| 95 | + |
| 96 | + while (iterator.hasNext()) { |
| 97 | + J9ClassPointer clsPointer = (J9ClassPointer)iterator.next(); |
| 98 | + String javaName = J9ClassHelper.getJavaName(clsPointer); |
| 99 | + if (className.equals(javaName)) { |
| 100 | + String hexString = clsPointer.getHexAddress(); |
| 101 | + classPointer = clsPointer; |
| 102 | + out.format("Found !j9class %s named %s%n", hexString, javaName); |
| 103 | + break; |
| 104 | + } |
| 105 | + } |
| 106 | + |
| 107 | + if (classPointer == null) { |
| 108 | + out.format("No class named %s found%n", className); |
| 109 | + return; |
| 110 | + } |
| 111 | + } catch (CorruptDataException e) { |
| 112 | + throw new DDRInteractiveCommandException(e); |
| 113 | + } |
| 114 | + |
| 115 | + /* Allocate a new instance of Table for each invocation of the command. */ |
| 116 | + data = new Table("Instances of " + className); |
| 117 | + data.row("Address", "Class Name"); |
| 118 | + |
| 119 | + /* Reset counts for each invocation of the command. */ |
| 120 | + corruptCount = 0; |
| 121 | + objectsFound = 0; |
| 122 | + |
| 123 | + scanHeap(); |
| 124 | + |
| 125 | + out.format("Objects found: %d%n", objectsFound); |
| 126 | + out.format("Corruptions encountered: %d%n", corruptCount); |
| 127 | + |
| 128 | + data.render(out); |
| 129 | + } |
| 130 | + |
| 131 | + private void scanHeap() { |
| 132 | + try { |
| 133 | + GCHeapRegionIterator regions = GCHeapRegionIterator.from(); |
| 134 | + while (regions.hasNext()) { |
| 135 | + GCHeapRegionDescriptor region = regions.next(); |
| 136 | + scanObjects(region); |
| 137 | + } |
| 138 | + } catch (CorruptDataException e) { |
| 139 | + e.printStackTrace(); |
| 140 | + } |
| 141 | + |
| 142 | + } |
| 143 | + |
| 144 | + private void scanObjects(GCHeapRegionDescriptor region) throws CorruptDataException { |
| 145 | + GCObjectHeapIterator heapIterator = GCObjectHeapIterator.fromHeapRegionDescriptor(region, true, true); |
| 146 | + while (heapIterator.hasNext()) { |
| 147 | + J9ObjectPointer object = heapIterator.next(); |
| 148 | + try { |
| 149 | + J9ClassPointer objClass = J9ObjectHelper.clazz(object); |
| 150 | + if (objClass.notNull() && J9ClassHelper.isSameOrSuperClassOf(classPointer, objClass)) { |
| 151 | + data.row(object.getHexAddress(), J9ClassHelper.getJavaName(objClass)); |
| 152 | + objectsFound += 1; |
| 153 | + } |
| 154 | + } catch (CorruptDataException e) { |
| 155 | + corruptCount += 1; |
| 156 | + } |
| 157 | + } |
| 158 | + } |
| 159 | +} |
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