1 /*
   2  * Copyright (c) 2017, 2018, Red Hat, Inc. 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 
  25 package gc.epsilon;
  26 
  27 /**
  28  * @test TestMemoryMXBeans
  29  * @requires vm.gc.Epsilon
  30  * @summary Test JMX memory beans
  31  * @modules java.base/jdk.internal.misc
  32  *          java.management
  33  * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC          -Xmx1g gc.epsilon.TestMemoryMXBeans   -1 1024
  34  * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -Xms1g   -Xmx1g gc.epsilon.TestMemoryMXBeans 1024 1024
  35  * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -Xms128m -Xmx1g gc.epsilon.TestMemoryMXBeans  128 1024
  36  */
  37 
  38 import java.lang.management.*;
  39 
  40 public class TestMemoryMXBeans {
  41 
  42     static volatile Object sink;
  43 
  44     public static void main(String[] args) throws Exception {
  45         if (args.length < 2) {
  46             throw new IllegalStateException("Should provide expected heap sizes");
  47         }
  48 
  49         long initSize = 1L * Integer.parseInt(args[0]) * 1024 * 1024;
  50         long maxSize =  1L * Integer.parseInt(args[1]) * 1024 * 1024;
  51 
  52         testMemoryBean(initSize, maxSize);
  53         testAllocs();
  54     }
  55 
  56     public static void testMemoryBean(long initSize, long maxSize) {
  57         MemoryMXBean memoryMXBean = ManagementFactory.getMemoryMXBean();
  58         long heapInit = memoryMXBean.getHeapMemoryUsage().getInit();
  59         long heapMax = memoryMXBean.getHeapMemoryUsage().getMax();
  60         memoryMXBean.getNonHeapMemoryUsage().getInit(); // value not used
  61         memoryMXBean.getNonHeapMemoryUsage().getMax();  // value not used
  62 
  63         if (initSize > 0 && heapInit != initSize) {
  64             throw new IllegalStateException("Init heap size is wrong: " + heapInit + " vs " + initSize);
  65         }
  66         if (maxSize > 0 && heapMax != maxSize) {
  67             throw new IllegalStateException("Max heap size is wrong: " + heapMax + " vs " + maxSize);
  68         }
  69     }
  70 
  71     public static void testAllocs() throws Exception {
  72         MemoryMXBean memoryMXBean = ManagementFactory.getMemoryMXBean();
  73 
  74         // Try multiple times, to capture either APIs we call allocate lazily, or the background threads allocating
  75         int maxTries = 10;
  76         int tries = 0;
  77 
  78         while (true) {
  79             // Compute how much we waste during the calls themselves:
  80             long heapUsed1 = memoryMXBean.getHeapMemoryUsage().getUsed();
  81             long heapUsed2 = memoryMXBean.getHeapMemoryUsage().getUsed();
  82             long adj = heapUsed2 - heapUsed1;
  83 
  84             heapUsed1 = memoryMXBean.getHeapMemoryUsage().getUsed();
  85             sink = new int[1024*1024];
  86             heapUsed2 = memoryMXBean.getHeapMemoryUsage().getUsed();
  87 
  88             long diff = heapUsed2 - heapUsed1 - adj;
  89             long min =  8 + 4*1024*1024;
  90             long max = 16 + 4*1024*1024;
  91             if ((min <= diff && diff <= max)) {
  92               // Success
  93               return;
  94             }
  95 
  96             if (tries++ > maxTries) {
  97               throw new IllegalStateException("Allocation did not change used space right: " + diff + " should be in [" + min + ", " + max + "]");
  98             }
  99 
 100             // Wait and try again
 101             Thread.sleep(1000);
 102         }
 103     }
 104 
 105 }