1 /*
   2  * Copyright (c) 2017, 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 if turning on/off/on the monitor wipes out the information.
  29  * @build Frame
  30  * @compile HeapMonitorOnOffTest.java
  31  * @run main/othervm/native -agentlib:HeapMonitor MyPackage.HeapMonitorOnOffTest
  32  */
  33 
  34 public class HeapMonitorOnOffTest {
  35   static {
  36     try {
  37       System.loadLibrary("HeapMonitor");
  38     } catch (UnsatisfiedLinkError ule) {
  39       System.err.println("Could not load HeapMonitor library");
  40       System.err.println("java.library.path: "
  41           + System.getProperty("java.library.path"));
  42       throw ule;
  43     }
  44   }
  45 
  46   private static int g_tmp[];
  47 
  48   private static int helper() {
  49     int sum = 0;
  50     // Let us assume that the array is 24 bytes of memory.
  51     for (int i = 0; i < 127000 / 6; i++) {
  52       int tmp[] = new int[1];
  53       // Force it to be kept.
  54       g_tmp = tmp;
  55       sum += g_tmp[0];
  56     }
  57     return sum;
  58   }
  59 
  60   private static void wrapper() {
  61     int sum = 0;
  62     for (int j = 0; j < 1000; j++) {
  63       sum += helper();
  64     }
  65     System.out.println(sum);
  66   }
  67 
  68   private native static int checkFrames(Frame[] frames);
  69   private native static int checkWipeOut(Frame[] frames);
  70   private native static int enableSampling();
  71   private native static int disableSampling();
  72 
  73   public static void main(String[] args) {
  74     Frame[] frames = new Frame[3];
  75     frames[0] = new Frame("helper", "()I", "HeapMonitorOnOffTest.java", 52);
  76     frames[1] = new Frame("wrapper", "()V", "HeapMonitorOnOffTest.java", 63);
  77     frames[2] = new Frame("main", "([Ljava/lang/String;)V", "HeapMonitorOnOffTest.java", 81);
  78 
  79     // Enable sampling and allocate.
  80     enableSampling();
  81     wrapper();
  82 
  83     // Now disable and re-enable.
  84     disableSampling();
  85 
  86     // Check that the data is still there: this allows to peruse samples after profiling.
  87     int status = checkFrames(frames);
  88     if (status != 0) {
  89       throw new RuntimeException("Failed to find the traces before the wipe out.");
  90     }
  91 
  92     // Enabling the sampling should wipe everything out.
  93     enableSampling();
  94 
  95     status = checkWipeOut(frames);
  96     if (status != 0) {
  97       throw new RuntimeException("Failed to wipe out the information.");
  98     }
  99   }
 100 }