diff -r c95334202a14 -r 1edcf36fe15f test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorStatIntervalTest.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorStatIntervalTest.java Wed Jul 18 11:57:51 2018 -0400 @@ -0,0 +1,91 @@ +/* + * Copyright (c) 2018, Google and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +package MyPackage; + +/** + * @test + * @summary Verifies the JVMTI Heap Monitor sampling interval average. + * @build Frame HeapMonitor + * @compile HeapMonitorStatIntervalTest.java + * @requires vm.compMode != "Xcomp" + * @run main/othervm/native -agentlib:HeapMonitorTest MyPackage.HeapMonitorStatIntervalTest + */ + +public class HeapMonitorStatIntervalTest { + + private native static double getAverageInterval(); + + private static boolean testIntervalOnce(int interval, boolean throwIfFailure) { + HeapMonitor.resetEventStorage(); + HeapMonitor.setSamplingInterval(interval); + + HeapMonitor.enableSamplingEvents(); + + int allocationTotal = 10 * 1024 * 1024; + int allocationIterations = 10; + + double actualCount = 0; + for (int i = 0; i < allocationIterations; i++) { + HeapMonitor.resetEventStorage(); + HeapMonitor.allocateSize(allocationTotal); + actualCount += HeapMonitor.getEventStorageElementCount(); + } + + HeapMonitor.disableSamplingEvents(); + + double expectedCount = allocationTotal * allocationIterations / interval; + + double error = Math.abs(actualCount - expectedCount); + double errorPercentage = error / expectedCount * 100; + + boolean success = (errorPercentage < 10.0); + + if (!success && throwIfFailure) { + throw new RuntimeException("Interval average over 10% for interval " + interval + " -> " + + actualCount + ", " + expectedCount); + } + + return success; + } + + + private static void testInterval(int interval) { + // Test the interval twice, it can happen that the test is "unlucky" and the interval just goes above + // the 10% mark. So try again to squash flakiness. + // Flakiness is due to the fact that this test is dependent on the sampling interval, which is a + // statistical geometric variable around the sampling interval. This means that the test could be + // unlucky and not achieve the mean average fast enough for the test case. + if (!testIntervalOnce(interval, false)) { + testIntervalOnce(interval, true); + } + } + + public static void main(String[] args) { + int[] tab = {1024, 8192}; + + for (int intervalIdx = 0; intervalIdx < tab.length; intervalIdx++) { + testInterval(tab[intervalIdx]); + } + } +}