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 * @summary Verifies the JVMTI Heap Monitor sampling rate average 29 * @build Frame HeapMonitor 30 * @compile HeapMonitorStatRateTest.java 31 * @run main/othervm/native -agentlib:HeapMonitorTest MyPackage.HeapMonitorStatRateTest 32 */ 33 34 public class HeapMonitorStatRateTest { 35 36 private native static double getAverageRate(); 37 38 private static boolean testRateOnce(int rate, boolean throwIfFailure) { 39 HeapMonitor.resetEventStorage(); 40 HeapMonitor.setSamplingRate(rate); 41 42 HeapMonitor.enableSamplingEvents(); 43 44 int allocationTotal = 512 * 1024 * 1024; 45 HeapMonitor.allocateSize(allocationTotal); 46 47 HeapMonitor.disableSamplingEvents(); 48 49 double actualCount = HeapMonitor.getEventStorageElementCount(); 50 double expectedCount = allocationTotal / rate; 51 52 double error = Math.abs(actualCount - expectedCount); 53 double errorPercentage = error / expectedCount * 100; 54 55 boolean failure = (errorPercentage > 10.0); 56 57 if (failure && throwIfFailure) { 58 throw new RuntimeException("Rate average over 10% for rate " + rate + " -> " + actualCount 59 + ", " + expectedCount); 60 } 61 62 return failure; 63 } 64 65 66 private static void testRate(int rate) { 67 // Test the rate twice, it can happen that the test is "unlucky" and the rate just goes above 68 // the 10% mark. So try again to squash flakiness. 69 if (!testRateOnce(rate, false)) { 70 testRateOnce(rate, true); 71 } 72 } 73 74 public static void main(String[] args) { 75 int[] tab = {1024, 16384, 524288}; 76 77 for (int rateIdx = 0; rateIdx < tab.length; rateIdx++) { 78 testRate(tab[rateIdx]); 79 } 80 } 81 }