1 /* 2 * Copyright (c) 2013, 2018, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.test.lib.jfr; 27 28 import jdk.test.lib.Asserts; 29 30 public class RecurseThread extends Thread { 31 32 public int totalDepth; 33 public long dummy = 0; // Just to make sure the optimizer does not remove the test code. 34 private volatile boolean timeToQuit = false; 35 private volatile boolean isInRunLoop = false; 36 37 public RecurseThread(int totalDepth) { 38 this.totalDepth = totalDepth; 39 } 40 41 @Override 42 public void run() { 43 // totalDepth includes functions run() and recurse() and runloop(). 44 // Remove 3 from totalDepth when recursing. 45 final int minDepth = 3; 46 Asserts.assertGreaterThanOrEqual(totalDepth, minDepth, "totalDepth too small"); 47 int recurseDepth = totalDepth - minDepth; 48 49 // We want the last function before runloop() to be recurseA(). 50 boolean startWithRecurseA = (totalDepth % 2) != 0; 51 dummy = startWithRecurseA ? recurseA(recurseDepth) : recurseB(recurseDepth); 52 } 53 54 public void quit() { 55 timeToQuit = true; 56 } 57 58 public boolean isInRunLoop() { 59 return isInRunLoop; 60 } 61 62 private long recurseA(int depth) { 63 if (depth == 0) { 64 return recurseEnd(); 65 } else { 66 return recurseB(depth - 1); 67 } 68 } 69 70 private long recurseB(int depth) { 71 if (depth == 0) { 72 return recurseEnd(); 73 } else { 74 return recurseA(depth - 1); 75 } 76 } 77 78 // Test expects this function to be at the top of the stack. 79 // We should not call other functions from here. 80 private long recurseEnd() { 81 isInRunLoop = true; 82 long[] dummyTable = new long[] { 0, 2, 4, 8, 16 }; 83 long dummyTotal = 0; 84 while (!timeToQuit) { 85 dummyTotal = 0; 86 for (int i = 0; i < 5; ++i) { 87 dummyTotal += dummyTable[i]; 88 } 89 } 90 return dummyTotal; 91 } 92 93 }