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/*
* 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;
import sun.misc.Perf;
import sun.jvmstat.monitor.*;
import java.util.*;
import java.io.*;
import java.lang.reflect.*;
import java.nio.ByteBuffer;
/**
* Abstraction for the HotSpot PerfData instrumentation buffer. This class
* is responsible for acquiring access to the instrumentation buffer for
* a target HotSpot Java Virtual Machine and providing method level access
* to its contents.
*
* @author Brian Doherty
* @since 1.5
*/
public abstract class AbstractPerfDataBuffer {
/**
* Reference to the concrete instance created by the
* {@link #createPerfDataBuffer} method.
*/
protected PerfDataBufferImpl impl;
/**
* 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 impl.getLocalVmId();
}
/**
* 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() {
return impl.getBytes();
}
/**
* Get the capacity of the instrumentation buffer.
*
* @return int - the capacity, or size, of the instrumentation buffer.
*/
public int getCapacity() {
return impl.getCapacity();
}
/**
* 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.
*
* @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 {
return impl.findByName(name);
}
/**
* 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 {
return impl.findByPattern(patternString);
}
/**
* 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 {
return impl.getMonitorStatus();
}
/**
* Get the ByteBuffer containing the instrumentation data.
*
* @return ByteBuffer - a ByteBuffer object that refers to the
* instrumentation data.
*/
public ByteBuffer getByteBuffer() {
return impl.getByteBuffer();
}
/**
* Create the perfdata instrumentation buffer for the given lvmid
* using the given ByteBuffer object as the source of the instrumentation
* data. This method parses the instrumentation buffer header to determine
* key characteristics of the instrumentation buffer and then dynamically
* loads the appropriate class to handle the particular instrumentation
* version.
*
* @param bb the ByteBuffer that references the instrumentation data.
* @param lvmid the Local Java Virtual Machine identifier for this
* instrumentation buffer.
*
* @throws MonitorException
*/
protected void createPerfDataBuffer(ByteBuffer bb, int lvmid)
throws MonitorException {
int majorVersion = AbstractPerfDataBufferPrologue.getMajorVersion(bb);
int minorVersion = AbstractPerfDataBufferPrologue.getMinorVersion(bb);
// instantiate the version specific class
String classname = "sun.jvmstat.perfdata.monitor.v"
+ majorVersion + "_" + minorVersion
+ ".PerfDataBuffer";
try {
Class implClass = Class.forName(classname);
Constructor cons = implClass.getConstructor(new Class[] {
Class.forName("java.nio.ByteBuffer"),
Integer.TYPE
});
impl = (PerfDataBufferImpl)cons.newInstance(new Object[] {
bb, new Integer(lvmid)
});
} catch (ClassNotFoundException e) {
// from Class.forName();
throw new IllegalArgumentException(
"Could not find " + classname + ": " + e.getMessage(), e);
} catch (NoSuchMethodException e) {
// from Class.getConstructor();
throw new IllegalArgumentException(
"Expected constructor missing in " + classname + ": "
+ e.getMessage(), e);
} catch (IllegalAccessException e) {
// from Constructor.newInstance()
throw new IllegalArgumentException(
"Unexpected constructor access in " + classname + ": "
+ e.getMessage(), e);
} catch (InstantiationException e) {
throw new IllegalArgumentException(
classname + "is abstract: " + e.getMessage(), e);
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
if (cause instanceof MonitorException) {
throw (MonitorException)cause;
}
throw new RuntimeException("Unexpected exception: "
+ e.getMessage() , e);
}
}
}