org.jikesrvm.objectmodel

Class MiscHeader

java.lang.Object

org.jikesrvm.objectmodel.MiscHeader

public final class MiscHeader
extends Object

Defines other header words not used for core Java language support of memory allocation. Typically these are extra header words used for various kinds of instrumentation or profiling.

See Also:

ObjectModel

Field Summary

Fields

Modifier and Type	Field and Description
private static Offset	MISC_HEADER_START
(package private) static Offset	OBJECT_DEATH_OFFSET
(package private) static Offset	OBJECT_LINK_OFFSET
(package private) static Offset	OBJECT_OID_OFFSET
private static Word	oid The next object ID to be used.
private static Word	prevAddress The address of the last object allocated into the header.
(package private) static int	REQUESTED_BITS How many available bits does the misc header want to use?
private static Word	time The current "time" for the trace being generated.

Constructor Summary

Constructors

Constructor and Description
MiscHeader()

Method Summary

Modifier and Type	Method and Description
static void	dumpHeader(Object ref) For low level debugging of GC subsystem.
static Address	getBootImageLink()
static Word	getDeathTime(Object object)
static int	getHeaderSize()
static ObjectReference	getLink(Object ref)
static Word	getOID()
static Word	getOID(Object object)
static void	initializeHeader(BootImageInterface bootImage, Address ref, TIB tib, int size, boolean isScalar) Perform any required initialization of the MISC portion of the header.
static void	initializeHeader(Object obj, TIB tib, int size, boolean isScalar) Perform any required initialization of the MISC portion of the header.
static void	setDeathTime(Object object, Word time_)
static void	setLink(Object object, ObjectReference link)
static void	setOID(Word oid_)
static void	updateDeathTime(Object object)
static void	updateTime(Word time_)

Methods inherited from class java.lang.Object

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

Field Detail

MISC_HEADER_START

private static final Offset MISC_HEADER_START

OBJECT_OID_OFFSET

static final Offset OBJECT_OID_OFFSET

OBJECT_DEATH_OFFSET

static final Offset OBJECT_DEATH_OFFSET

OBJECT_LINK_OFFSET

static final Offset OBJECT_LINK_OFFSET

REQUESTED_BITS

static final int REQUESTED_BITS

How many available bits does the misc header want to use?

See Also:

Constant Field Values

oid

private static Word oid

The next object ID to be used.

time

private static Word time

The current "time" for the trace being generated.

prevAddress

private static Word prevAddress

The address of the last object allocated into the header.

Constructor Detail

MiscHeader

public MiscHeader()

Method Detail

initializeHeader

public static void initializeHeader(Object obj,
                                    TIB tib,
                                    int size,
                                    boolean isScalar)

Perform any required initialization of the MISC portion of the header.

Parameters:

obj - the object ref to the storage to be initialized

tib - the TIB of the instance being created

size - the number of bytes allocated by the GC system for this object.

isScalar - are we initializing a scalar (true) or array (false) object?

initializeHeader

public static void initializeHeader(BootImageInterface bootImage,
                                    Address ref,
                                    TIB tib,
                                    int size,
                                    boolean isScalar)

Perform any required initialization of the MISC portion of the header.

Parameters:

bootImage - the bootimage being written

ref - the object ref to the storage to be initialized

tib - the TIB of the instance being created

size - the number of bytes allocated by the GC system for this object.

isScalar - are we initializing a scalar (true) or array (false) object?

updateDeathTime

public static void updateDeathTime(Object object)

setDeathTime

public static void setDeathTime(Object object,
                                Word time_)

setLink

public static void setLink(Object object,
                           ObjectReference link)

updateTime

public static void updateTime(Word time_)

getOID

public static Word getOID(Object object)

getDeathTime

public static Word getDeathTime(Object object)

getLink

public static ObjectReference getLink(Object ref)

getBootImageLink

public static Address getBootImageLink()

getOID

public static Word getOID()

setOID

public static void setOID(Word oid_)

getHeaderSize

public static int getHeaderSize()

dumpHeader

public static void dumpHeader(Object ref)

For low level debugging of GC subsystem. Dump the header word(s) of the given object reference.

Parameters:

ref - the object reference whose header should be dumped