|
1 /* |
|
2 * Copyright (c) 2013, 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 package gc.testlibrary; |
|
25 |
|
26 import sun.jvmstat.monitor.Monitor; |
|
27 |
|
28 /** |
|
29 * Represents a performance counter in the JVM. |
|
30 * |
|
31 * See http://openjdk.java.net/groups/hotspot/docs/Serviceability.html#bjvmstat |
|
32 * for more details about performance counters. |
|
33 */ |
|
34 public class PerfCounter { |
|
35 private final Monitor monitor; |
|
36 private final String name; |
|
37 |
|
38 PerfCounter(Monitor monitor, String name) { |
|
39 this.monitor = monitor; |
|
40 this.name = name; |
|
41 } |
|
42 |
|
43 /** |
|
44 * Returns the value of this performance counter as a long. |
|
45 * |
|
46 * @return The long value of this performance counter |
|
47 * @throws RuntimeException If the value of the performance counter isn't a long |
|
48 */ |
|
49 public long longValue() { |
|
50 Object value = monitor.getValue(); |
|
51 if (value instanceof Long) { |
|
52 return ((Long) value).longValue(); |
|
53 } |
|
54 throw new RuntimeException("Expected " + monitor.getName() + " to have a long value"); |
|
55 } |
|
56 |
|
57 /** |
|
58 * Returns the name of the performance counter. |
|
59 * |
|
60 * @return The name of the performance counter. |
|
61 */ |
|
62 public String getName() { |
|
63 return name; |
|
64 } |
|
65 |
|
66 @Override |
|
67 public String toString() { |
|
68 return name; |
|
69 } |
|
70 } |