org.mmtk.utility.sanitychecker

Class SanityDataTable

java.lang.Object

org.mmtk.utility.SimpleHashtable

org.mmtk.utility.sanitychecker.SanityDataTable

public final class SanityDataTable
extends SimpleHashtable

This class implements a simple hashtable to store and retrieve per object information for sanity checking.

This class is not thread safe.

Field Summary

Fields

Modifier and Type	Field and Description
private static int	NORMAL_RC_BITS The number of bits for the normal reference count
private static int	NORMAL_RC_INC The increment to use for normal increments
private static int	NORMAL_RC_MASK The mask for the normal reference count
private static int	ROOT_RC_INC The increment to use for root increments
private static int	ROOT_RC_SHIFT The shift for the root reference count

Constructor Summary

Constructors

Constructor and Description
SanityDataTable(RawPageSpace rps, int logSize) Create a new data table of a specified size.

Method Summary

Modifier and Type	Method and Description
void	forwardTable(TraceLocal trace) Forward data table using the supplied trace.
Address	getEntry(ObjectReference object, boolean create) Get an entry for an object.
static int	getNormalRC(Address entry) Given an address of an entry, read the reference count, excluding root references.
static ObjectReference	getObjectReference(Address entry) Given an address of an entry, read the reference component.
static int	getRC(Address entry) Given an address of an entry, read the total reference count.
static int	getRootRC(Address entry) Given an address of an entry, read the root reference count.
static boolean	incRC(Address entry, boolean root) Increment the data word for an object.
void	pushNotInOther(SanityDataTable other, ObjectReferenceDeque deque) Push any entries that are only in this table, and not the passed table.

Methods inherited from class org.mmtk.utility.SimpleHashtable

acquireTable, contains, getEntry, getFirst, getKey, getNext, getPayloadAddress, getPayloadAddress, isValid, releaseTable, replaceKey

Methods inherited from class java.lang.Object

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

Field Detail

NORMAL_RC_BITS

private static final int NORMAL_RC_BITS

The number of bits for the normal reference count

See Also:

Constant Field Values

NORMAL_RC_MASK

private static final int NORMAL_RC_MASK

The mask for the normal reference count

See Also:

Constant Field Values

ROOT_RC_SHIFT

private static final int ROOT_RC_SHIFT

The shift for the root reference count

See Also:

Constant Field Values

NORMAL_RC_INC

private static final int NORMAL_RC_INC

The increment to use for normal increments

See Also:

Constant Field Values

ROOT_RC_INC

private static final int ROOT_RC_INC

The increment to use for root increments

See Also:

Constant Field Values

Constructor Detail

SanityDataTable

public SanityDataTable(RawPageSpace rps,
                       int logSize)

Create a new data table of a specified size.

Parameters:

rps - The space to acquire the data structure from.

logSize - The log of the number of table entries.

Method Detail

incRC

public static boolean incRC(Address entry,
                            boolean root)

Increment the data word for an object.

Parameters:

entry - The table entry.

root - True if this is a root reference.

Returns:

True if this is the first ref to that object.

pushNotInOther

public void pushNotInOther(SanityDataTable other,
                           ObjectReferenceDeque deque)

Push any entries that are only in this table, and not the passed table. This does not compare values.

Parameters:

other - The table to use for comparison.

deque - The buffer to push results onto.

getNormalRC

public static int getNormalRC(Address entry)

Given an address of an entry, read the reference count, excluding root references.

Parameters:

entry - The entry

Returns:

The reference count.

getRootRC

public static int getRootRC(Address entry)

Given an address of an entry, read the root reference count.

Parameters:

entry - The entry

Returns:

The root reference count.

getRC

public static int getRC(Address entry)

Given an address of an entry, read the total reference count.

Parameters:

entry - The entry

Returns:

The total reference count.

getObjectReference

public static ObjectReference getObjectReference(Address entry)

Given an address of an entry, read the reference component.

Parameters:

entry - The entry

Returns:

The object reference.

forwardTable

public void forwardTable(TraceLocal trace)

Forward data table using the supplied trace. Note that the data is not hashed correctly, so only enumeration can be used without rehashing.

Parameters:

trace - The trace to use.

getEntry

public Address getEntry(ObjectReference object,
                        boolean create)

Get an entry for an object.

Parameters:

object - The object to find an entry for.

create - Create an entry if none exists?

Returns:

The entry address.