org.mmtk.policy.immix

Class ObjectHeader

java.lang.Object

org.mmtk.policy.immix.ObjectHeader

public class ObjectHeader
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static int	AVAILABLE_LOCAL_BITS number of header bits we may use
static int	GC_HEADER_WORDS_REQUIRED
static int	GLOBAL_GC_BITS_REQUIRED
static int	LOCAL_GC_BITS_REQUIRED
private static byte	MARK_AND_FORWARDING_MASK
private static int	MARK_BASE
static byte	MARK_BASE_VALUE
private static byte	MARK_INCREMENT
static byte	MARK_MASK
(package private) static int	MAX_MARKCOUNT_BITS
(package private) static byte	NEW_OBJECT_MARK
static byte	PINNED_BIT
static int	PINNED_BIT_NUMBER
static byte	STRADDLE_BIT
private static int	STRADDLE_BIT_NUMBER

Constructor Summary

Constructors

Constructor and Description
ObjectHeader()

Method Summary

Modifier and Type	Method and Description
(package private) static byte	deltaMarkState(byte state, boolean increment) Return the mark state incremented or decremented by one.
(package private) static boolean	isMatureObject(ObjectReference object)
(package private) static boolean	isNewObject(ObjectReference object)
(package private) static boolean	isPinnedObject(ObjectReference object)
(package private) static boolean	isStraddlingObject(ObjectReference object)
(package private) static void	markAsStraddling(ObjectReference object)
static void	pinObject(ObjectReference object)
(package private) static void	returnToPriorStateAndEnsureUnlogged(ObjectReference object, byte status)
(package private) static void	setMarkStateUnlogAndUnlock(ObjectReference object, byte gcByte, byte markState)
(package private) static byte	testAndMark(ObjectReference object, byte markState) Non-atomically test and set the mark bit of an object.
(package private) static boolean	testMarkState(byte gcByte, byte value)
(package private) static boolean	testMarkState(ObjectReference object, byte value) Return true if the mark count for an object has the given value.
(package private) static void	writeMarkState(ObjectReference object, byte markState, boolean straddle) Write the allocState into the mark state fields of an object non-atomically.

Methods inherited from class java.lang.Object

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

Field Detail

AVAILABLE_LOCAL_BITS

static final int AVAILABLE_LOCAL_BITS

number of header bits we may use

LOCAL_GC_BITS_REQUIRED

public static final int LOCAL_GC_BITS_REQUIRED

GLOBAL_GC_BITS_REQUIRED

public static final int GLOBAL_GC_BITS_REQUIRED

See Also:

Constant Field Values

GC_HEADER_WORDS_REQUIRED

public static final int GC_HEADER_WORDS_REQUIRED

See Also:

Constant Field Values

NEW_OBJECT_MARK

static final byte NEW_OBJECT_MARK

See Also:

Constant Field Values

PINNED_BIT_NUMBER

public static final int PINNED_BIT_NUMBER

See Also:

Constant Field Values

PINNED_BIT

public static final byte PINNED_BIT

See Also:

Constant Field Values

STRADDLE_BIT_NUMBER

private static final int STRADDLE_BIT_NUMBER

See Also:

Constant Field Values

STRADDLE_BIT

public static final byte STRADDLE_BIT

See Also:

Constant Field Values

MARK_BASE

private static final int MARK_BASE

See Also:

Constant Field Values

MAX_MARKCOUNT_BITS

static final int MAX_MARKCOUNT_BITS

MARK_INCREMENT

private static final byte MARK_INCREMENT

See Also:

Constant Field Values

MARK_MASK

public static final byte MARK_MASK

MARK_AND_FORWARDING_MASK

private static final byte MARK_AND_FORWARDING_MASK

MARK_BASE_VALUE

public static final byte MARK_BASE_VALUE

See Also:

Constant Field Values

Constructor Detail

ObjectHeader

public ObjectHeader()

Method Detail

testAndMark

static byte testAndMark(ObjectReference object,
                        byte markState)

Non-atomically test and set the mark bit of an object.

Parameters:

object - The object whose mark bit is to be written

markState - The value to which the mark bits will be set

Returns:

the old mark state

setMarkStateUnlogAndUnlock

static void setMarkStateUnlogAndUnlock(ObjectReference object,
                                       byte gcByte,
                                       byte markState)

testMarkState

static boolean testMarkState(ObjectReference object,
                             byte value)

Return true if the mark count for an object has the given value.

Parameters:

object - The object whose mark bit is to be tested

value - The value against which the mark bit will be tested

Returns:

true if the mark bit for the object has the given value.

testMarkState

static boolean testMarkState(byte gcByte,
                             byte value)

isNewObject

static boolean isNewObject(ObjectReference object)

isMatureObject

static boolean isMatureObject(ObjectReference object)

markAsStraddling

static void markAsStraddling(ObjectReference object)

isStraddlingObject

static boolean isStraddlingObject(ObjectReference object)

pinObject

public static void pinObject(ObjectReference object)

isPinnedObject

static boolean isPinnedObject(ObjectReference object)

writeMarkState

static void writeMarkState(ObjectReference object,
                           byte markState,
                           boolean straddle)

Write the allocState into the mark state fields of an object non-atomically. This is appropriate for collection time initialization.

Parameters:

object - The object whose mark state is to be written

markState - TODO: what am I?

straddle - TODO: what am I?

returnToPriorStateAndEnsureUnlogged

static void returnToPriorStateAndEnsureUnlogged(ObjectReference object,
                                                byte status)

deltaMarkState

static byte deltaMarkState(byte state,
                           boolean increment)

Return the mark state incremented or decremented by one.

Parameters:

state - the mark state

increment - If true, then return the incremented value else return the decremented value

Returns:

the mark state incremented or decremented by one.