--- /dev/null 2018-03-08 15:11:46.002676589 -0800 +++ new/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java 2018-03-19 14:01:31.901553593 -0700 @@ -0,0 +1,102 @@ +/* + * 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 + * @build Frame HeapMonitor + * @summary Verifies the JVMTI Heap Monitor Thread sanity + * @compile HeapMonitorThreadTest.java + * @run main/othervm/native -agentlib:HeapMonitor MyPackage.HeapMonitorThreadTest + */ + +import java.util.ArrayList; +import java.util.List; + +public class HeapMonitorThreadTest { + private native static boolean checkSamples(int numThreads); + + public static void main(String[] args) { + final int numThreads = 24; + ArrayList list = new ArrayList<>(); + + // Remember a lot of garbage to have space for all thread samples. + HeapMonitor.enableSamplingRate(); + HeapMonitor.setGarbageHistory(10000); + + for (int i = 0 ; i < numThreads; i++) { + Thread thread = new Thread(new Allocator(i), "Allocator" + i); + thread.start(); + list.add(thread); + } + + for (Thread elem : list) { + try { + elem.join(); + } catch(InterruptedException e) { + throw new RuntimeException("Thread got interrupted..."); + } + } + + if (!checkSamples(numThreads)) { + throw new RuntimeException("Problem with checkSamples..."); + } + } +} + +class Allocator implements Runnable { + private int depth; + private volatile int tmp[]; + + public Allocator(int depth) { + this.depth = depth; + } + + private int helper() { + int sum = 0; + // Let us assume that the array is 24 bytes of memory. + for (int i = 0; i < 127000 / 6; i++) { + int newTmp[] = new int[1]; + // Force it to be kept. + tmp = newTmp; + sum += tmp[0]; + } + return sum; + } + + private int recursiveWrapper(int depth) { + if (depth > 0) { + return recursiveWrapper(depth - 1); + } + return helper(); + } + + public void run() { + int sum = 0; + for (int j = 0; j < 50; j++) { + sum += recursiveWrapper(depth); + } + System.out.println(sum); + } +}