1 /* 2 * Copyright (c) 2000, 2006, 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 package sun.jvm.hotspot.utilities; 26 27 import sun.jvm.hotspot.memory.*; 28 import sun.jvm.hotspot.oops.*; 29 30 /** This class wraps a user's chosen HeapVisitor with the 31 functionality that a chosen "thunk" is called periodically during 32 the heap traversal. This allows a progress bar to be displayed 33 during long heap scans. */ 34 35 public class ProgressiveHeapVisitor implements HeapVisitor { 36 private HeapVisitor userHeapVisitor; 37 private HeapProgressThunk thunk; 38 private long usedSize; 39 private long visitedSize; 40 private double lastNotificationFraction; 41 private static double MINIMUM_NOTIFICATION_FRACTION = 0.01; 42 ProgressiveHeapVisitor(HeapVisitor userHeapVisitor, HeapProgressThunk thunk)43 public ProgressiveHeapVisitor(HeapVisitor userHeapVisitor, 44 HeapProgressThunk thunk) { 45 this.userHeapVisitor = userHeapVisitor; 46 this.thunk = thunk; 47 } 48 prologue(long usedSize)49 public void prologue(long usedSize) { 50 this.usedSize = usedSize; 51 visitedSize = 0; 52 userHeapVisitor.prologue(usedSize); 53 } 54 doObj(Oop obj)55 public boolean doObj(Oop obj) { 56 userHeapVisitor.doObj(obj); 57 visitedSize += obj.getObjectSize(); 58 double curFrac = (double) visitedSize / (double) usedSize; 59 if (curFrac > lastNotificationFraction + MINIMUM_NOTIFICATION_FRACTION) { 60 thunk.heapIterationFractionUpdate(curFrac); 61 lastNotificationFraction = curFrac; 62 } 63 return false; 64 } 65 epilogue()66 public void epilogue() { 67 userHeapVisitor.epilogue(); 68 thunk.heapIterationComplete(); 69 } 70 } 71