1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2018, Google and/or its affiliates. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  */
  24 
  25 package MyPackage;
  26 
  27 /**
  28  * @test
  29  * @build Frame HeapMonitor ThreadInformation
  30  * @summary Verifies the JVMTI Heap Monitor Thread can disable events for a given thread.
  31  * @compile HeapMonitorThreadDisabledTest.java
  32  * @run main/othervm/native -Xmx512m -agentlib:HeapMonitorTest MyPackage.HeapMonitorThreadDisabledTest
  33  * @requires !vm.gc.Z
  34  */
  35 
  36 import java.util.List;
  37 
  38 public class HeapMonitorThreadDisabledTest {
  39   private native static void enableSamplingEvents(Thread thread);
  40   private native static boolean checkThreadSamplesOnlyFrom(Thread thread);
  41 
  42   public static void main(String[] args) {
  43     final int numThreads = 4;
  44     List<ThreadInformation> threadList = ThreadInformation.createThreadList(numThreads);
  45 
  46     // Sample at a interval of 8k.
  47     HeapMonitor.setSamplingInterval(1 << 13);
  48 
  49     // Only enable the sampling for a given thread.
  50     Thread thread = threadList.get(0).getThread();
  51     enableSamplingEvents(thread);
  52 
  53     System.err.println("Starting threads");
  54     ThreadInformation.startThreads(threadList);
  55     ThreadInformation.waitForThreads(threadList);
  56     System.err.println("Waited for threads");
  57 
  58     // Only have the samples for a given thread should be captured.
  59     if (!checkThreadSamplesOnlyFrom(thread)) {
  60       throw new RuntimeException(
  61           "Problem with checkSamples: got no events from the expected  thread");
  62     }
  63 
  64     // Now inform each thread we are done and wait for them to be done.
  65     ThreadInformation.stopThreads(threadList);
  66   }
  67 }