| /* |
| * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| import sun.jvmstat.monitor.Monitor; |
| |
| /** |
| * Represents a performance counter in the JVM. |
| * |
| * See http://openjdk.java.net/groups/hotspot/docs/Serviceability.html#bjvmstat |
| * for more details about performance counters. |
| */ |
| public class PerfCounter { |
| private final Monitor monitor; |
| private final String name; |
| |
| PerfCounter(Monitor monitor, String name) { |
| this.monitor = monitor; |
| this.name = name; |
| } |
| |
| /** |
| * Returns the value of this performance counter as a long. |
| * |
| * @return The long value of this performance counter |
| * @throws RuntimeException If the value of the performance counter isn't a long |
| */ |
| public long longValue() { |
| Object value = monitor.getValue(); |
| if (value instanceof Long) { |
| return ((Long) value).longValue(); |
| } |
| throw new RuntimeException("Expected " + monitor.getName() + " to have a long value"); |
| } |
| |
| /** |
| * Returns the name of the performance counter. |
| * |
| * @return The name of the performance counter. |
| */ |
| public String getName() { |
| return name; |
| } |
| |
| @Override |
| public String toString() { |
| return name; |
| } |
| } |