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 import java.io.PrintStream;
  35 
  36 public class HeapMonitorOnOffTest {
  37 
  38   static {
  39     try {
  40       System.loadLibrary("HeapMonitor");
  41     } catch (UnsatisfiedLinkError ule) {
  42       System.err.println("Could not load HeapMonitor library");
  43       System.err.println("java.library.path: "
  44           + System.getProperty("java.library.path"));
  45       throw ule;
  46     }
  47   }
  48 
  49   public static int helper() {
  50     int sum = 0;
  51     // Let us assume that the array is 24 bytes of memory.
  52     for (int i = 0; i < 127000 / 6; i++) {
  53       int tmp[] = new int[1];
  54       // Force it to be kept.
  55       g_tmp = tmp;
  56       sum += g_tmp[0];
  57     }
  58     return sum;
  59   }
  60 
  61   public static void wrapper() {
  62     int sum = 0;
  63     for (int j = 0; j < 1000; j++) {
  64       sum += helper();
  65     }
  66     System.out.println(sum);
  67   }
  68 
  69   native static int checkFrames(Frame[] frames);
  70   native static int checkWipeOut(Frame[] frames);
  71   native static int enableSampling();
  72   native static int disableSampling();
  73 
  74   public static int cnt;
  75   public static int g_tmp[];
  76   public int array[];
  77 
  78   public static void main(String[] args) {
  79     Frame[] frames = new Frame[3];
  80     frames[0] = new Frame("helper", "()I", "HeapMonitorOnOffTest.java", 53);
  81     frames[1] = new Frame("wrapper", "()V", "HeapMonitorOnOffTest.java", 64);
  82     frames[2] = new Frame("main", "([Ljava/lang/String;)V", "HeapMonitorOnOffTest.java", 86);
  83 
  84     // Enable sampling and allocate.
  85     enableSampling();
  86     wrapper();
  87 
  88     // Now disable and re-enable.
  89     disableSampling();
  90 
  91     // Check that the data is still there: this allows to peruse samples after profiling.
  92     int status = checkFrames(frames);
  93     if (status != 0) {
  94       throw new RuntimeException("Failed to find the traces before the wipe out.");
  95     }
  96 
  97     // Enabling the sampling should wipe everything out.
  98     enableSampling();
  99 
 100     status = checkWipeOut(frames);
 101     if (status != 0) {
 102       throw new RuntimeException("Failed to wipe out the information.");
 103     }
 104   }
 105 }