1 /* 2 * Copyright (c) 2018, Google 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 package MyPackage; 25 26 /** 27 * @test 28 * @build Frame HeapMonitor 29 * @summary Verifies the JVMTI Heap Monitor Thread sanity 30 * @compile HeapMonitorThreadOnOffTest.java 31 * @run main/othervm/native -agentlib:HeapMonitor MyPackage.HeapMonitorThreadOnOffTest 32 */ 33 34 import java.util.ArrayList; 35 import java.util.List; 36 37 public class HeapMonitorThreadOnOffTest { 38 public static void main(String[] args) { 39 final int numThreads = 24; 40 ArrayList<Thread> list = new ArrayList<>(); 41 42 // Add one thread that consistently turns on/off the sampler to ensure correctness with 43 // potential resets. 44 Switch switchPlayer = new Switch(); 45 Thread switchThread = new Thread(switchPlayer, "Switch Player"); 46 switchThread.start(); 47 48 for (int i = 0 ; i < numThreads; i++) { 49 Thread thread = new Thread(new Allocator(i), "Allocator" + i); 50 thread.start(); 51 list.add(thread); 52 } 53 54 for (Thread elem : list) { 55 try { 56 elem.join(); 57 } catch(InterruptedException e) { 58 throw new RuntimeException("Thread got interrupted..."); 59 } 60 } 61 62 switchPlayer.stop(); 63 try { 64 switchThread.join(); 65 } catch(InterruptedException e) { 66 throw new RuntimeException("Thread got interrupted while waiting for the switch player..."); 67 } 68 69 // We don't check here for correctness of data. If we made it here, the test succeeded: 70 // Threads can allocate like crazy 71 // Other threads can turn on/off the system 72 } 73 } 74 75 class Allocator implements Runnable { 76 private int depth; 77 private volatile int tmp[]; 78 79 public Allocator(int depth) { 80 this.depth = depth; 81 } 82 83 private int helper() { 84 int sum = 0; 85 // Let us assume that the array is 24 bytes of memory. 86 for (int i = 0; i < 127000 / 6; i++) { 87 int newTmp[] = new int[1]; 88 // Force it to be kept. 89 tmp = newTmp; 90 sum += tmp[0]; 91 } 92 return sum; 93 } 94 95 private int recursiveWrapper(int depth) { 96 if (depth > 0) { 97 return recursiveWrapper(depth - 1); 98 } 99 return helper(); 100 } 101 102 public void run() { 103 int sum = 0; 104 for (int j = 0; j < 500; j++) { 105 sum += recursiveWrapper(depth); 106 } 107 } 108 } 109 110 class Switch implements Runnable { 111 private volatile boolean keepGoing; 112 113 public Switch() { 114 keepGoing = true; 115 } 116 117 public void stop() { 118 keepGoing = false; 119 } 120 121 public void run() { 122 while (keepGoing) { 123 HeapMonitor.disableSamplingRate(); 124 HeapMonitor.resetEventStorage(); 125 HeapMonitor.enableSamplingRate(); 126 } 127 } 128 }