platform
Class VMPerfDataFile

java.lang.Object
  platform.VMPerfDataFile

public final class VMPerfDataFile
extends java.lang.Object

Util class to retrieve various details about running virtual machines.

Author:

Christian Banse

Field Summary

private java.lang.Object	m_buff The buffer used to read from the data file.
private boolean	m_bUsable This class will only be usable on some java runtimes
private static java.lang.reflect.Method	m_byteBufferGetIntMethod ByteBuffer.getInt()
private static java.lang.reflect.Method	m_byteBufferGetMethod ByteBuffer.get()
private static java.lang.reflect.Method	m_byteBufferPositionMethod ByteBuffer.position(int)
private static java.lang.Class	m_javaNioByteBufferClass java.nio.ByteBuffer
private static java.lang.Class	m_javaNioByteOrderClass java.nio.ByteOrder
private int	m_nextEntry Position of the next data entry in the byte buffer
private int	m_numEntries Data entry count
private java.lang.Object	m_perf The underlaying perfomance data object Original type: sun.misc.Perf
private static java.lang.Class	m_sunMiscPerfClass sun.misc.Perf
private java.util.Hashtable	m_tblEntries The performance data entries
private int	m_vmId The id of the virtual machine
private static java.lang.Integer	PERFDATA_ACCESSIBLE_POSITION Position of the accessible byte
private static java.lang.Integer	PERFDATA_BYTEORDER_POSITION Position of the byte order
private static java.lang.Integer	PERFDATA_ENTRYOFFSET_POSITION Position of the data entries
private static int	PERFDATA_MAGIC The magic integer
private static java.lang.Integer	PERFDATA_MAGIC_POSITION Position of the magic integer
private static java.lang.Integer	PERFDATA_NUMENTRIES_POSITION Position of the data entry count
private static int	PERFDATA_SYNC_TIMEOUT Virtual machine sync timeout

Constructor Summary

VMPerfDataFile(int a_vmId)
Creates a new VMPerfDataFile with the specified id.

Method Summary

private boolean	buildEntries() Builds all data entries from the byte buffer
private boolean	buildNextEntry() Builds the next data entry
private java.lang.Object	getByteOrder() Returns the byte order of the underlaying perfomance file Original return type: java.nio.ByteOrder
int	getId() Returns the id of the Virtual Machine
private int	getMagic() Gets the magic integer of the VM datafile
java.lang.String	getMainClass() Returns the main class of the Virtual Machine
private boolean	isAccessible() Checks if the VM perf data file is accessible
boolean	isUsable() Checks if the Class is usable with the current VM
java.lang.String	toString() toString() helper class

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

m_tblEntries

private java.util.Hashtable m_tblEntries

The performance data entries

m_buff

private java.lang.Object m_buff

The buffer used to read from the data file. Original type: java.nio.ByteBuffer

m_perf

private java.lang.Object m_perf

The underlaying perfomance data object Original type: sun.misc.Perf

m_bUsable

private boolean m_bUsable

This class will only be usable on some java runtimes

m_nextEntry

private int m_nextEntry

Position of the next data entry in the byte buffer

m_numEntries

private int m_numEntries

Data entry count

PERFDATA_MAGIC_POSITION

private static final java.lang.Integer PERFDATA_MAGIC_POSITION

Position of the magic integer

PERFDATA_BYTEORDER_POSITION

private static final java.lang.Integer PERFDATA_BYTEORDER_POSITION

Position of the byte order

PERFDATA_ACCESSIBLE_POSITION

private static final java.lang.Integer PERFDATA_ACCESSIBLE_POSITION

Position of the accessible byte

PERFDATA_ENTRYOFFSET_POSITION

private static final java.lang.Integer PERFDATA_ENTRYOFFSET_POSITION

Position of the data entries

PERFDATA_NUMENTRIES_POSITION

private static final java.lang.Integer PERFDATA_NUMENTRIES_POSITION

Position of the data entry count

PERFDATA_MAGIC

private static final int PERFDATA_MAGIC

The magic integer

See Also:

Constant Field Values

PERFDATA_SYNC_TIMEOUT

private static final int PERFDATA_SYNC_TIMEOUT

Virtual machine sync timeout

See Also:

Constant Field Values

m_javaNioByteBufferClass

private static java.lang.Class m_javaNioByteBufferClass

java.nio.ByteBuffer

m_javaNioByteOrderClass

private static java.lang.Class m_javaNioByteOrderClass

java.nio.ByteOrder

m_sunMiscPerfClass

private static java.lang.Class m_sunMiscPerfClass

sun.misc.Perf

m_byteBufferPositionMethod

private static java.lang.reflect.Method m_byteBufferPositionMethod

ByteBuffer.position(int)

m_byteBufferGetMethod

private static java.lang.reflect.Method m_byteBufferGetMethod

ByteBuffer.get()

m_byteBufferGetIntMethod

private static java.lang.reflect.Method m_byteBufferGetIntMethod

ByteBuffer.getInt()

m_vmId

private int m_vmId

The id of the virtual machine

Constructor Detail

VMPerfDataFile

public VMPerfDataFile(int a_vmId)

Creates a new VMPerfDataFile with the specified id.

Parameters:

a_vmId - Id of the Virtual Machine

Method Detail

buildEntries

private boolean buildEntries()
                      throws java.lang.Exception

Builds all data entries from the byte buffer

Returns:

true if the build was successful, false otherwise

Throws:

java.lang.Exception

buildNextEntry

private boolean buildNextEntry()
                        throws java.lang.Exception

Builds the next data entry

Returns:

true if the build was succesful, false otherwise

Throws:

java.lang.Exception

isAccessible

private boolean isAccessible()
                      throws java.lang.Exception

Checks if the VM perf data file is accessible

Returns:

true if the VM is accessible, false otherwise

Throws:

java.lang.Exception

getMagic

private int getMagic()
              throws java.lang.Exception

Gets the magic integer of the VM datafile

Returns:

the magic integer

Throws:

java.lang.Exception

getByteOrder

private java.lang.Object getByteOrder()
                               throws java.lang.Exception

Returns the byte order of the underlaying perfomance file Original return type: java.nio.ByteOrder

Returns:

the byte order

Throws:

java.lang.Exception

getMainClass

public java.lang.String getMainClass()

Returns the main class of the Virtual Machine

Returns:

the main class as String

getId

public int getId()

Returns the id of the Virtual Machine

Returns:

the id

toString

public java.lang.String toString()

toString() helper class

Overrides:

toString in class java.lang.Object

Returns:

the main class

isUsable

public boolean isUsable()

Checks if the Class is usable with the current VM

Returns:

true if the Class is usable, false otherwise