/* * Copyright (c) 2009, 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.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * 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 sun.misc; import java.nio.ByteBuffer;import java.nio.ByteOrder;import java.nio.LongBuffer;import java.security.AccessController; /** * Performance counter support for internal JRE classes. * This class defines a fixed list of counters for the platform * to use as an interim solution until RFE# 6209222 is implemented. * The perf counters will be created in the jvmstat perf buffer * that the HotSpot VM creates. The default size is 32K and thus * the number of counters is bounded.  You can alter the size * with -XX:PerfDataMemorySize=<bytes> option. If there is * insufficient memory in the jvmstat perf buffer, the C heap memory * will be used and thus the application will continue to run if * the counters added exceeds the buffer size but the counters * will be missing. * * See HotSpot jvmstat implementation for certain circumstances * that the jvmstat perf buffer is not supported. * */public class PerfCounter {    private static final Perf perf =        AccessController.doPrivileged(new Perf.GetPerfAction());     // Must match values defined in hotspot/src/share/vm/runtime/perfdata.hpp    private final static int V_Constant  = 1;    private final static int V_Monotonic = 2;    private final static int V_Variable  = 3;    private final static int U_None      = 1;     private final String name;    private final LongBuffer lb;     private PerfCounter(String name, int type) {        this.name = name;        ByteBuffer bb = perf.createLong(name, U_None, type, 0L);        bb.order(ByteOrder.nativeOrder());        this.lb = bb.asLongBuffer();    }     static PerfCounter newPerfCounter(String name) {        return new PerfCounter(name, V_Variable);    }     static PerfCounter newConstantPerfCounter(String name) {        PerfCounter c = new PerfCounter(name, V_Constant);        return c;    }     /**     * Returns the current value of the perf counter.     */    public synchronized long get() {        return lb.get(0);    }     /**     * Sets the value of the perf counter to the given newValue.     */    public synchronized void set(long newValue) {        lb.put(0, newValue);    }     /**     * Adds the given value to the perf counter.     */    public synchronized void add(long value) {        long res = get() + value;        lb.put(0, res);    }     /**     * Increments the perf counter with 1.     */    public void increment() {        add(1);    }     /**     * Adds the given interval to the perf counter.     */    public void addTime(long interval) {        add(interval);    }     /**     * Adds the elapsed time from the given start time (ns) to the perf counter.     */    public void addElapsedTimeFrom(long startTime) {        add(System.nanoTime() - startTime);    }     @Override    public String toString() {        return name + " = " + get();    }     static class CoreCounters {        static final PerfCounter pdt   = newPerfCounter("sun.classloader.parentDelegationTime");        static final PerfCounter lc    = newPerfCounter("sun.classloader.findClasses");        static final PerfCounter lct   = newPerfCounter("sun.classloader.findClassTime");        static final PerfCounter rcbt  = newPerfCounter("sun.urlClassLoader.readClassBytesTime");        static final PerfCounter zfc   = newPerfCounter("sun.zip.zipFiles");        static final PerfCounter zfot  = newPerfCounter("sun.zip.zipFile.openTime");    }     static class WindowsClientCounters {        static final PerfCounter d3dAvailable = newConstantPerfCounter("sun.java2d.d3d.available");    }     /**     * Number of findClass calls     */    public static PerfCounter getFindClasses() {        return CoreCounters.lc;    }     /**     * Time (ns) spent in finding classes that includes     * lookup and read class bytes and defineClass     */    public static PerfCounter getFindClassTime() {        return CoreCounters.lct;    }     /**     * Time (ns) spent in finding classes     */    public static PerfCounter getReadClassBytesTime() {        return CoreCounters.rcbt;    }     /**     * Time (ns) spent in the parent delegation to     * the parent of the defining class loader     */    public static PerfCounter getParentDelegationTime() {        return CoreCounters.pdt;    }     /**     * Number of zip files opened.     */    public static PerfCounter getZipFileCount() {        return CoreCounters.zfc;    }     /**     * Time (ns) spent in opening the zip files that     * includes building the entries hash table     */    public static PerfCounter getZipFileOpenTime() {        return CoreCounters.zfot;    }     /**     * D3D graphic pipeline available     */    public static PerfCounter getD3DAvailable() {        return WindowsClientCounters.d3dAvailable;    }}