| /* |
| * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved. |
| * Copyright (c) 2020, 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 does not always sample the first object. |
| * @build Frame HeapMonitor |
| * @compile HeapMonitorInitialAllocationTest.java |
| * @run main/othervm/native -agentlib:HeapMonitorTest MyPackage.HeapMonitorInitialAllocationTest |
| */ |
| public class HeapMonitorInitialAllocationTest { |
| public static void main(String[] args) throws Exception { |
| final int numThreads = 500; |
| |
| // Allocate the threads first to not risk sampling. |
| Thread threads[] = new Thread[numThreads]; |
| for (int i = 0; i < numThreads ; i++) { |
| threads[i] = new Thread(new Task(), "Task " + i); |
| } |
| |
| HeapMonitor.setSamplingInterval(1024 * 1024); |
| HeapMonitor.enableSamplingEvents(); |
| |
| for (int i = 0; i < numThreads ; i++) { |
| threads[i].start(); |
| } |
| |
| for (int i = 0; i < numThreads ; i++) { |
| threads[i].join(); |
| } |
| |
| HeapMonitor.disableSamplingEvents(); |
| |
| int sampledEvents = HeapMonitor.sampledEvents(); |
| if (sampledEvents > numThreads / 2) { |
| throw new RuntimeException( |
| "Sampling the initial allocation too many times: " + sampledEvents); |
| } |
| } |
| |
| private static class Task implements Runnable { |
| @Override |
| public void run() { |
| new EmptyObject(); |
| } |
| } |
| |
| private static class EmptyObject { |
| } |
| } |