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