/*
 * Copyright (c) 2003, 2012, 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.management.snmp.jvminstr;

// java imports
//
import com.sun.jmx.mbeanserver.Util;
import java.io.Serializable;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;


// jmx imports
//
import javax.management.MBeanServer;
import javax.management.ObjectName;
import com.sun.jmx.snmp.SnmpOid;
import com.sun.jmx.snmp.SnmpStatusException;

// jdmk imports
//
import com.sun.jmx.snmp.agent.SnmpMib;
import com.sun.jmx.snmp.agent.SnmpMibSubRequest;
import com.sun.jmx.snmp.agent.SnmpStandardObjectServer;

import java.lang.management.MemoryPoolMXBean;
import java.lang.management.ManagementFactory;

import sun.management.snmp.jvmmib.JvmMemPoolTableMeta;
import sun.management.snmp.util.SnmpTableCache;
import sun.management.snmp.util.SnmpNamedListTableCache;
import sun.management.snmp.util.SnmpTableHandler;
import sun.management.snmp.util.MibLogger;
import sun.management.snmp.util.JvmContextFactory;

The class is used for implementing the "JvmMemPoolTable" group.
/** * The class is used for implementing the "JvmMemPoolTable" group. */
public class JvmMemPoolTableMetaImpl extends JvmMemPoolTableMeta { static final long serialVersionUID = -2525820976094284957L;
A concrete implementation of SnmpNamedListTableCache, for the jvmMemPoolTable.
/** * A concrete implementation of {@link SnmpNamedListTableCache}, for the * jvmMemPoolTable. **/
private static class JvmMemPoolTableCache extends SnmpNamedListTableCache { static final long serialVersionUID = -1755520683086760574L;
Create a weak cache for the jvmMemPoolTable.
Params:
  • validity – validity of the cached data, in ms.
/** * Create a weak cache for the jvmMemPoolTable. * @param validity validity of the cached data, in ms. **/
JvmMemPoolTableCache(long validity) { this.validity = validity; }
Use the MemoryPoolMXBean name as key.
Params:
  • context – A TreeMap as allocated by the parent SnmpNamedListTableCache class.
  • rawDatas – List of MemoryPoolMXBean, as returned by ManagementFactory.getMemoryPoolMXBeans()
  • rank – The rank of item in the list.
  • item – The rankth MemoryPoolMXBean in the list.
Returns: ((MemoryPoolMXBean)item).getName()
/** * Use the MemoryPoolMXBean name as key. * @param context A {@link TreeMap} as allocated by the parent * {@link SnmpNamedListTableCache} class. * @param rawDatas List of {@link MemoryPoolMXBean}, as * returned by * <code>ManagementFactory.getMemoryPoolMXBeans()</code> * @param rank The <var>rank</var> of <var>item</var> in the list. * @param item The <var>rank</var><super>th</super> * <code>MemoryPoolMXBean</code> in the list. * @return <code>((MemoryPoolMXBean)item).getName()</code> **/
protected String getKey(Object context, List<?> rawDatas, int rank, Object item) { if (item == null) return null; final String name = ((MemoryPoolMXBean)item).getName(); log.debug("getKey", "key=" + name); return name; }
Call getTableDatas(JvmContextFactory.getUserData()).
/** * Call <code>getTableDatas(JvmContextFactory.getUserData())</code>. **/
public SnmpTableHandler getTableHandler() { final Map<Object, Object> userData = JvmContextFactory.getUserData(); return getTableDatas(userData); }
Return the key used to cache the raw data of this table.
/** * Return the key used to cache the raw data of this table. **/
protected String getRawDatasKey() { return "JvmMemManagerTable.getMemoryPools"; }
Call ManagementFactory.getMemoryPoolMXBeans() to load the raw data of this table.
/** * Call ManagementFactory.getMemoryPoolMXBeans() to * load the raw data of this table. **/
protected List<MemoryPoolMXBean> loadRawDatas(Map<Object, Object> userData) { return ManagementFactory.getMemoryPoolMXBeans(); } } // The weak cache for this table. protected SnmpTableCache cache;
Constructor for the table. Initialize metadata for "JvmMemPoolTableMeta".
/** * Constructor for the table. * Initialize metadata for "JvmMemPoolTableMeta". */
public JvmMemPoolTableMetaImpl(SnmpMib myMib, SnmpStandardObjectServer objserv) { super(myMib,objserv); this.cache = new JvmMemPoolTableCache(((JVM_MANAGEMENT_MIB_IMPL)myMib). validity()*30); } // See com.sun.jmx.snmp.agent.SnmpMibTable protected SnmpOid getNextOid(Object userData) throws SnmpStatusException { // null means get the first OID. return getNextOid(null,userData); } // See com.sun.jmx.snmp.agent.SnmpMibTable protected SnmpOid getNextOid(SnmpOid oid, Object userData) throws SnmpStatusException { final boolean dbg = log.isDebugOn(); try { if (dbg) log.debug("getNextOid", "previous=" + oid); // Get the data handler. // SnmpTableHandler handler = getHandler(userData); if (handler == null) { // This should never happen. // If we get here it's a bug. // if (dbg) log.debug("getNextOid", "handler is null!"); throw new SnmpStatusException(SnmpStatusException.noSuchInstance); } // Get the next oid // final SnmpOid next = handler.getNext(oid); if (dbg) log.debug("getNextOid", "next=" + next); // if next is null: we reached the end of the table. // if (next == null) throw new SnmpStatusException(SnmpStatusException.noSuchInstance); return next; } catch (SnmpStatusException x) { if (dbg) log.debug("getNextOid", "End of MIB View: " + x); throw x; } catch (RuntimeException r) { if (dbg) log.debug("getNextOid", "Unexpected exception: " + r); if (dbg) log.debug("getNextOid",r); throw r; } } // See com.sun.jmx.snmp.agent.SnmpMibTable protected boolean contains(SnmpOid oid, Object userData) { // Get the handler. // SnmpTableHandler handler = getHandler(userData); // handler should never be null. // if (handler == null) return false; return handler.contains(oid); } // See com.sun.jmx.snmp.agent.SnmpMibTable public Object getEntry(SnmpOid oid) throws SnmpStatusException { if (oid == null) throw new SnmpStatusException(SnmpStatusException.noSuchInstance); // Get the request contextual cache (userData). // final Map<Object, Object> m = Util.cast(JvmContextFactory.getUserData()); // We know in the case of this table that the index is an integer, // it is thus the first OID arc of the index OID. // final long index = oid.getOidArc(0); // We're going to use this name to store/retrieve the entry in // the request contextual cache. // // Revisit: Probably better programming to put all these strings // in some interface. // final String entryTag = ((m==null)?null:("JvmMemPoolTable.entry." + index)); // If the entry is in the cache, simply return it. // if (m != null) { final Object entry = m.get(entryTag); if (entry != null) return entry; } // The entry was not in the cache, make a new one. // // Get the data hanler. // SnmpTableHandler handler = getHandler(m); // handler should never be null. // if (handler == null) throw new SnmpStatusException(SnmpStatusException.noSuchInstance); // Get the data associated with our entry. // final Object data = handler.getData(oid); // data may be null if the OID we were given is not valid. // if (data == null) throw new SnmpStatusException(SnmpStatusException.noSuchInstance); // make the new entry (transient object that will be kept only // for the duration of the request. // if (log.isDebugOn()) log.debug("getEntry","data is a: " + data.getClass().getName()); final Object entry = new JvmMemPoolEntryImpl((MemoryPoolMXBean)data,(int)index); // Put the entry in the cache in case we need it later while processing // the request. // if (m != null && entry != null) { m.put(entryTag,entry); } return entry; }
Get the SnmpTableHandler that holds the jvmMemPoolTable data. First look it up in the request contextual cache, and if it is not found, obtain it from the weak cache.
The request contextual cache will be released at the end of the current requests, and is used only to process this request.
The weak cache is shared by all requests, and is only recomputed when it is found to be obsolete.
Note that the data put in the request contextual cache is never considered to be obsolete, in order to preserve data coherency.
/** * Get the SnmpTableHandler that holds the jvmMemPoolTable data. * First look it up in the request contextual cache, and if it is * not found, obtain it from the weak cache. * <br>The request contextual cache will be released at the end of the * current requests, and is used only to process this request. * <br>The weak cache is shared by all requests, and is only * recomputed when it is found to be obsolete. * <br>Note that the data put in the request contextual cache is * never considered to be obsolete, in order to preserve data * coherency. **/
protected SnmpTableHandler getHandler(Object userData) { final Map<Object, Object> m; if (userData instanceof Map) m = Util.cast(userData); else m = null; // Look in the contextual cache. if (m != null) { final SnmpTableHandler handler = (SnmpTableHandler)m.get("JvmMemPoolTable.handler"); if (handler != null) return handler; } // No handler in contextual cache, make a new one. final SnmpTableHandler handler = cache.getTableHandler(); if (m != null && handler != null ) m.put("JvmMemPoolTable.handler",handler); return handler; } static final MibLogger log = new MibLogger(JvmMemPoolTableMetaImpl.class); }