/* * Copyright (c) 2004, 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.jvmstat.perfdata.monitor.protocol.local; import sun.misc.Perf;import sun.jvmstat.monitor.*;import sun.jvmstat.perfdata.monitor.*;import java.util.*;import java.io.*;import java.nio.ByteBuffer;import java.nio.channels.FileChannel;import java.lang.reflect.Constructor;import java.security.AccessController; /** * The concrete PerfDataBuffer implementation for the <em>local:</em> * protocol for the HotSpot PerfData monitoring implementation. * <p> * This class is responsible for acquiring access to the shared memory * instrumentation buffer for the target HotSpot Java Virtual Machine. * * @author Brian Doherty * @since 1.5 */// Suppreess unchecked conversion warning at line 34.//@SuppressWarnings("unchecked")public class PerfDataBuffer extends AbstractPerfDataBuffer {    private static final Perf perf = AccessController.doPrivileged(new Perf.GetPerfAction());     /**     * Create a PerfDataBuffer instance for accessing the specified     * instrumentation buffer.     *     * @param vmid the <em>local:</em> URI specifying the target JVM.     *     * @throws MonitorException     */    public PerfDataBuffer(VmIdentifier vmid) throws MonitorException {        try {            // Try 1.4.2 and later first            ByteBuffer bb = perf.attach(vmid.getLocalVmId(), vmid.getMode());            createPerfDataBuffer(bb, vmid.getLocalVmId());         } catch (IllegalArgumentException e) {            // now try 1.4.1 by attempting to directly map the files.            try {                String filename = PerfDataFile.getTempDirectory()                                  + PerfDataFile.dirNamePrefix                                  + Integer.toString(vmid.getLocalVmId());                 File f = new File(filename);                 FileChannel fc = new RandomAccessFile(f, "r").getChannel();                ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0L,                                       (int)fc.size());                fc.close();                createPerfDataBuffer(bb, vmid.getLocalVmId());             } catch (FileNotFoundException e2) {                // re-throw the exception from the 1.4.2 attach method                throw new MonitorException(vmid.getLocalVmId() + " not found",                                           e);            } catch (IOException e2) {                throw new MonitorException("Could not map 1.4.1 file for "                                           + vmid.getLocalVmId(), e2);            }        } catch (IOException e) {            throw new MonitorException("Could not attach to "                                       + vmid.getLocalVmId(), e);        }    }}