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/*
* Copyright (c) 2004, 2013, 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;
import sun.jvmstat.monitor.*;
import java.util.*;
import java.nio.*;
import java.io.*;
import java.net.*;
import java.util.regex.*;
/**
* The base classes for the concrete implementations of the HotSpot
* PerfData instrumentation buffer.
*
* @author Brian Doherty
* @since 1.5
* @see AbstractPerfDataBuffer
*/
public abstract class PerfDataBufferImpl {
/**
* The buffer containing the instrumentation data.
*/
protected ByteBuffer buffer;
/**
* A Map of monitor objects found in the instrumentation buffer.
*/
protected Map monitors;
/**
* The Local Java Virtual Machine Identifier for this buffer.
*/
protected int lvmid;
/**
* A Map of monitor object names to aliases as read in from the alias map
* file.
*/
protected Map> aliasMap;
/**
* A cache of resolved monitor aliases.
*/
protected Map aliasCache;
/**
* Constructor.
*
* @param buffer the ByteBuffer containing the instrumentation data.
* @param lvmid the Local Java Virtual Machine Identifier for this
* instrumentation buffer.
*/
protected PerfDataBufferImpl(ByteBuffer buffer, int lvmid) {
this.buffer = buffer;
this.lvmid = lvmid;
this.monitors = new TreeMap();
this.aliasMap = new HashMap>();
this.aliasCache = new HashMap();
}
/**
* Get the Local Java Virtual Machine Identifier, or lvmid
* for the target JVM associated with this instrumentation buffer.
*
* @return int - the lvmid
*/
public int getLocalVmId() {
return lvmid;
}
/**
* Get a copy of the raw instrumentation data.
* This method is used to get a copy of the current bytes in the
* instrumentation buffer. It is generally used for transporting
* those bytes over the network.
*
* @return byte[] - a copy of the bytes in the instrumentation buffer.
*/
public byte[] getBytes() {
ByteBuffer bb = null;
synchronized (this) {
/*
* this operation is potentially time consuming, and the result
* is unused when the getBytes() interface is used. However, the
* call is necessary in order to synchronize this monitoring
* client with the target jvm, which assures that the receiver
* of the byte[] gets an image that is initialized to a usable
* state. Otherwise, they might only get a snapshot of an
* empty instrumentation buffer immediately after it was created.
*/
try {
if (monitors.isEmpty()) {
buildMonitorMap(monitors);
}
} catch (MonitorException e) {
/*
* just ignore this here and let the receiver of the
* byte[] detect and handle the problem.
*/
}
bb = buffer.duplicate();
}
bb.rewind();
byte[] bytes = new byte[bb.limit()];
bb.get(bytes);
return bytes;
}
/**
* Get the capacity of the instrumentation buffer.
*
* @return int - the capacity, or size, of the instrumentation buffer.
*/
public int getCapacity() {
return buffer.capacity();
}
/**
* Get the ByteBuffer containing the instrumentation data.
*
* @return ByteBuffer - a ByteBuffer object that refers to the
* instrumentation data.
*/
ByteBuffer getByteBuffer() {
// receiver is responsible for assuring that the buffer's state
// is that of an initialized target.
return buffer;
}
/**
* Build the alias mapping. Uses the default alias map file unless
* the sun.jvmstat.perfdata.aliasmap file indicates some other
* file as the source.
*/
private void buildAliasMap() {
assert Thread.holdsLock(this);
URL aliasURL = null;
String filename = System.getProperty("sun.jvmstat.perfdata.aliasmap");
if (filename != null) {
File f = new File(filename);
try {
aliasURL = f.toURL();
} catch (MalformedURLException e) {
throw new IllegalArgumentException(e);
}
} else {
aliasURL = getClass().getResource(
"/sun/jvmstat/perfdata/resources/aliasmap");
}
assert aliasURL != null;
AliasFileParser aliasParser = new AliasFileParser(aliasURL);
try {
aliasParser.parse(aliasMap);
} catch (IOException e) {
System.err.println("Error processing " + filename + ": "
+ e.getMessage());
} catch (SyntaxException e) {
System.err.println("Syntax error parsing " + filename + ": "
+ e.getMessage());
}
}
/**
* Find the Monitor object for the named counter by using one of its
* aliases.
*/
protected Monitor findByAlias(String name) {
assert Thread.holdsLock(this);
Monitor m = (Monitor)aliasCache.get(name);
if (m == null) {
ArrayList al = aliasMap.get(name);
if (al != null) {
for (Iterator i = al.iterator(); i.hasNext() && m == null; ) {
String alias = (String)i.next();
m = (Monitor)monitors.get(alias);
}
}
}
return m;
}
/**
* Find a named Instrumentation object.
*
* This method will look for the named instrumentation object in the
* instrumentation exported by this Java Virtual Machine. If an
* instrumentation object with the given name exists, a Monitor interface
* to that object will be return. Otherwise, the method returns
* null. The method will map requests for instrumention objects
* using old names to their current names, if applicable.
*
*
*
* @param name the name of the Instrumentation object to find.
* @return Monitor - the {@link Monitor} object that can be used to
* monitor the the named instrumentation object, or
* null if the named object doesn't exist.
* @throws MonitorException Thrown if an error occurs while communicating
* with the target Java Virtual Machine.
*/
public Monitor findByName(String name) throws MonitorException {
Monitor m = null;
synchronized (this) {
if (monitors.isEmpty()) {
buildMonitorMap(monitors);
buildAliasMap();
}
// look for the requested monitor
m = monitors.get(name);
if (m == null) {
// not found - load any new monitors, and try again.
getNewMonitors(monitors);
m = monitors.get(name);
}
if (m == null) {
// still not found, look for aliases
m = findByAlias(name);
}
}
return m;
}
/**
* Find all Instrumentation objects with names matching the given pattern.
*
* This method returns a {@link List} of Monitor objects such that
* the name of each object matches the given pattern.
*
* @param patternString a string containing a pattern as described in
* {@link java.util.regex.Pattern}.
* @return List - a List of {@link Monitor} objects that can be used to
* monitor the instrumentation objects whose names match
* the given pattern. If no instrumentation objects have`
* names matching the given pattern, then an empty List
* is returned.
* @throws MonitorException Thrown if an error occurs while communicating
* with the target Java Virtual Machine.
* @see java.util.regex.Pattern
*/
public List findByPattern(String patternString)
throws MonitorException, PatternSyntaxException {
synchronized(this) {
if (monitors.isEmpty()) {
buildMonitorMap(monitors);
} else {
getNewMonitors(monitors);
}
}
Pattern pattern = Pattern.compile(patternString);
Matcher matcher = pattern.matcher("");
List matches = new ArrayList();
Set monitorSet = monitors.entrySet();
for (Iterator i = monitorSet.iterator(); i.hasNext(); /* empty */) {
Map.Entry me = (Map.Entry)i.next();
String name = (String)me.getKey();
Monitor m = (Monitor)me.getValue();
// apply pattern to monitor item name
matcher.reset(name);
// if the pattern matches, then add monitor to list
if (matcher.lookingAt()) {
matches.add((Monitor)me.getValue());
}
}
return matches;
}
/**
* Get a list of the inserted and removed monitors since last called.
*
* @return MonitorStatus - the status of available Monitors for the
* target Java Virtual Machine.
* @throws MonitorException Thrown if communications errors occur
* while communicating with the target.
*/
public MonitorStatus getMonitorStatus() throws MonitorException {
synchronized(this) {
if (monitors.isEmpty()) {
buildMonitorMap(monitors);
}
return getMonitorStatus(monitors);
}
}
// PerfDataBuffer implementation specific classes
/**
* get the list of inserted and removed monitors since last called.
*
* @param m the map of Monitors.
* @throws MonitorException Thrown if communications errors occur
* while communicating with the target.
*/
protected abstract MonitorStatus getMonitorStatus(Map m)
throws MonitorException;
/**
* build the map of Monitor objects.
*
* @param m the map of Monitors.
* @throws MonitorException Thrown if communications errors occur
* while communicating with the target.
*/
protected abstract void buildMonitorMap(Map m) throws MonitorException;
/**
* get the new Monitor objects from the Map of Monitor objects.
*
* @param m the map of Monitors.
* @throws MonitorException Thrown if communications errors occur
* while communicating with the target.
*/
protected abstract void getNewMonitors(Map m) throws MonitorException;
}