--- /dev/null Fri Mar 7 14:51:09 2014 +++ new/test/testlibrary/com/oracle/java/testlibrary/PerfCounter.java Fri Mar 7 14:51:06 2014 @@ -0,0 +1,70 @@ +/* + * Copyright (c) 2013, 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. + */ + +package com.oracle.java.testlibrary; + +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; + } +}