1 /*
   2  * Copyright (c) 2003, 2015, Oracle 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 /*
  25  * @test
  26  * @bug     4858522
  27  * @summary Basic unit test of OperatingSystemMXBean.getFreePhysicalMemorySize()
  28  * @author  Steve Bohne
  29  * @modules jdk.management
  30  */
  31 
  32 /*
  33  * This test is just a sanity check and does not check for the correct
  34  * value.  The correct value should be checked manually:
  35  * Solaris:
  36  *   1. In a shell, enter the command: "sar -r 1"
  37  *   2. The value (reported in pages) is in the "freemem" column.
  38  * Linux:
  39  *   1. In a shell, enter the command: "cat /proc/meminfo"
  40  *   2. The value (reported in bytes) is in "Mem" entry, "free" column.
  41  * Windows NT/XP/2000:
  42  *   1. Hit Ctrl-Alt-Delete, select Task Manager, go to Performance tab.
  43  *   2. The value (reported in Kbytes) is in the entry "Available" in the
  44  *      "Physical Memory" box.
  45  * Windows 98/ME:
  46  *   1. Run Start->Programs->Accessories->System Tools->System Information.
  47  *   2. Use the "XXXMB RAM" and "XX% system resources free" to determine free
  48  *      physical memory.
  49  */
  50 
  51 import com.sun.management.OperatingSystemMXBean;
  52 import java.lang.management.*;
  53 
  54 public class GetFreePhysicalMemorySize {
  55 
  56     private static OperatingSystemMXBean mbean =
  57         (com.sun.management.OperatingSystemMXBean)
  58         ManagementFactory.getOperatingSystemMXBean();
  59 
  60     // Careful with these values.
  61     private static final long MIN_SIZE_FOR_PASS = 1;
  62     // Max size for pass dynamically determined below.
  63     private static long       max_size_for_pass = Long.MAX_VALUE;
  64 
  65     private static boolean trace = false;
  66 
  67     public static void main(String args[]) throws Exception {
  68         if (args.length > 0 && args[0].equals("trace")) {
  69             trace = true;
  70         }
  71 
  72         long max_size = mbean.getTotalPhysicalMemorySize();
  73         if (max_size > 0) {
  74             max_size_for_pass = max_size;
  75         }
  76 
  77         long size = mbean.getFreePhysicalMemorySize();
  78 
  79         if (trace) {
  80             System.out.println("Free physical memory size in bytes: " + size);
  81         }
  82 
  83         if (size < MIN_SIZE_FOR_PASS || size > max_size_for_pass) {
  84             throw new RuntimeException("Free physical memory size " +
  85                                        "illegal value: " + size + " bytes " +
  86                                        "(MIN = " + MIN_SIZE_FOR_PASS + "; " +
  87                                        "MAX = " + max_size_for_pass + ")");
  88         }
  89 
  90         System.out.println("Test passed.");
  91     }
  92 }