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 
  26 package sun.jvmstat.perfdata.monitor;
  27 
  28 import java.util.List;
  29 
  30 import sun.jvmstat.monitor.*;
  31 import sun.jvmstat.monitor.event.VmListener;
  32 
  33 /**
  34  * Base class for all MonitoredVm implementations that utilize the
  35  * HotSpot PerfData instrumentation buffer as the communications
  36  * mechanism to the target Java Virtual Machine.
  37  *
  38  * @author Brian Doherty
  39  * @since 1.5
  40  */
  41 public abstract class AbstractMonitoredVm implements BufferedMonitoredVm {
  42 
  43     /**
  44      * The VmIdentifier for the target.
  45      */
  46     protected VmIdentifier vmid;
  47 
  48     /**
  49      * The shared memory instrumentation buffer for the target.
  50      */
  51     protected AbstractPerfDataBuffer pdb;
  52 
  53     /**
  54      * The sampling interval, if the instrumentation buffer is acquired
  55      * by sampling instead of shared memory mechanisms.
  56      */
  57     protected int interval;
  58 
  59     /**
  60      * Create an AbstractMonitoredVm instance.
  61      *
  62      * @param vmid the VmIdentifier for the target
  63      * @param interval the initial sampling interval
  64      */
  65     public AbstractMonitoredVm(VmIdentifier vmid, int interval)
  66            throws MonitorException {
  67         this.vmid = vmid;
  68         this.interval = interval;
  69     }
  70 
  71     /**
  72      * {@inheritDoc}
  73      */
  74     public VmIdentifier getVmIdentifier() {
  75         return vmid;
  76     }
  77 
  78     /**
  79      * {@inheritDoc}
  80      */
  81     public Monitor findByName(String name) throws MonitorException {
  82         return pdb.findByName(name);
  83     }
  84 
  85     /**
  86      * {@inheritDoc}
  87      */
  88     public List<Monitor> findByPattern(String patternString) throws MonitorException {
  89         return pdb.findByPattern(patternString);
  90     }
  91 
  92     /**
  93      * {@inheritDoc}
  94      */
  95     public void detach() {
  96         /*
  97          * no default action required because the detach operation for the
  98          * native byte buffer is managed by the sun.misc.Perf class.
  99          */
 100     }
 101 
 102 
 103     /* ---- Methods to support polled MonitoredVm Implementations ----- */
 104 
 105     /**
 106      * {@inheritDoc}
 107      */
 108     public void setInterval(int interval) {
 109         this.interval = interval;
 110     }
 111 
 112     /**
 113      * {@inheritDoc}
 114      */
 115     public int getInterval() {
 116         return interval;
 117     }
 118 
 119     /**
 120      * {@inheritDoc}
 121      */
 122     public void setLastException(Exception e) {
 123         // XXX: implement
 124     }
 125 
 126     /**
 127      * {@inheritDoc}
 128      */
 129     public Exception getLastException() {
 130         // XXX: implement
 131         return null;
 132     }
 133 
 134     /**
 135      * {@inheritDoc}
 136      */
 137     public void clearLastException() {
 138         // XXX: implement
 139     }
 140 
 141     /**
 142      * {@inheritDoc}
 143      */
 144     public boolean isErrored() {
 145         // XXX: implement
 146         return false;
 147     }
 148 
 149     /**
 150      * Get a list of the inserted and removed monitors since last called.
 151      *
 152      * @return MonitorStatus - the status of available Monitors for the
 153      *                         target Java Virtual Machine.
 154      * @throws MonitorException Thrown if communications errors occur
 155      *                          while communicating with the target.
 156      */
 157     public MonitorStatus getMonitorStatus() throws MonitorException {
 158         return pdb.getMonitorStatus();
 159     }
 160 
 161 
 162     /* --------------- Methods to support VmListeners ----------------- */
 163 
 164     /**
 165      * {@inheritDoc}
 166      */
 167     public abstract void addVmListener(VmListener l);
 168 
 169     /**
 170      * {@inheritDoc}
 171      */
 172     public abstract void removeVmListener(VmListener l);
 173 
 174 
 175     /* ---- Methods to support BufferedMonitoredVm Implementations ---- */
 176 
 177     /**
 178      * {@inheritDoc}
 179      */
 180     public byte[] getBytes() {
 181         return pdb.getBytes();
 182     }
 183 
 184     /**
 185      * {@inheritDoc}
 186      */
 187     public int getCapacity() {
 188         return pdb.getCapacity();
 189     }
 190 }