1/* 2 * Copyright (c) 2004, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package sun.jvmstat.perfdata.monitor.protocol.rmi; 27 28import sun.jvmstat.monitor.*; 29import sun.jvmstat.monitor.remote.*; 30import sun.jvmstat.perfdata.monitor.*; 31import java.io.*; 32import java.rmi.RemoteException; 33import java.nio.ByteBuffer; 34 35/** 36 * The concrete PerfDataBuffer implementation for the <em>rmi:</em> 37 * protocol for the HotSpot PerfData monitoring implementation. 38 * <p> 39 * This class is responsible for acquiring the instrumentation buffer 40 * data for a remote target HotSpot Java Virtual Machine. 41 * 42 * @author Brian Doherty 43 * @since 1.5 44 */ 45public class PerfDataBuffer extends AbstractPerfDataBuffer { 46 47 private RemoteVm rvm; 48 49 /** 50 * Create a PerfDataBuffer instance for accessing the specified 51 * instrumentation buffer. 52 * 53 * @param rvm the proxy to the remote MonitredVm object 54 * @param lvmid the local Java Virtual Machine Identifier of the 55 * remote target. 56 * 57 * @throws MonitorException 58 */ 59 public PerfDataBuffer(RemoteVm rvm, int lvmid) throws MonitorException { 60 61 this.rvm = rvm; 62 try { 63 ByteBuffer buffer = ByteBuffer.allocate(rvm.getCapacity()); 64 sample(buffer); 65 createPerfDataBuffer(buffer, lvmid); 66 67 } catch (RemoteException e) { 68 throw new MonitorException("Could not read data for remote JVM " 69 + lvmid, e); 70 } 71 } 72 73 /** 74 * Get a copy of the remote instrumentation buffer. 75 *<p> 76 * The data in the remote instrumentation buffer is copied into 77 * the local byte buffer. 78 * 79 * @param buffer the buffer to receive the copy of the remote 80 * instrumentation buffer. 81 * @throws RemoteException Thrown on any communications errors with 82 * the remote system. 83 */ 84 public void sample(ByteBuffer buffer) throws RemoteException { 85 assert buffer != null; 86 assert rvm != null; 87 synchronized(buffer) { 88 buffer.clear(); 89 buffer.put(rvm.getBytes()); 90 } 91 } 92} 93