org.jikesrvm.mm.mmtk
Class FinalizableProcessor

java.lang.Object
  org.mmtk.vm.FinalizableProcessor
      org.jikesrvm.mm.mmtk.FinalizableProcessor

All Implemented Interfaces:

SizeConstants

public final class FinalizableProcessor
extends FinalizableProcessor
implements SizeConstants

This class manages the processing of finalizable objects.

TODO can this be a linked list?

finalizableProcessor

private static final FinalizableProcessor finalizableProcessor

The FinalizableProcessor singleton

STRESS

private static final boolean STRESS

Stress the system?

See Also:

Constant Field Values

INITIAL_SIZE

private static final int INITIAL_SIZE

Initial size of the reference object table

See Also:

Constant Field Values

GROWTH_FACTOR

private static final double GROWTH_FACTOR

Amount to grow the table by when it is filled

See Also:

Constant Field Values

lock

private final Lock lock

Used to ensure mutual exclusion during table manipulation

table

protected volatile AddressArray table

The table of candidates

readyForFinalize

protected volatile Object[] readyForFinalize

The table of ready objects

nurseryIndex

protected int nurseryIndex

Index of first entry created since last collection

maxIndex

protected volatile int maxIndex

Index of the first free slot in the table.

nextReadyIndex

private volatile int nextReadyIndex

Next object ready to be finalized

lastReadyIndex

private volatile int lastReadyIndex

Last object ready to be finalized

FinalizableProcessor

protected FinalizableProcessor()

Create a new table.

add

public void add(Object object)

Allocate an entry in the table. This should be called from an unpreemptible context so that the entry can be filled. This method is responsible for growing the table if necessary.

clear

public void clear()

Description copied from class: FinalizableProcessor

Clear the contents of the table. This is called when finalization is disabled to make it easier for VMs to change this setting at runtime.

Specified by:

clear in class FinalizableProcessor

forward

public void forward(TraceLocal trace,
                    boolean nursery)

Iterate over and forward entries in the table..

Currently ignores the nursery hint.

TODO parallelise this code?

Specified by:

forward in class FinalizableProcessor

Parameters:

trace - The trace

nursery - Is this a nursery collection ?

scan

public void scan(TraceLocal trace,
                 boolean nursery)

Scan through the list of references. Calls ReferenceProcessor's processReference method for each reference and builds a new list of those references still active.

Depending on the value of nursery, we will either scan all references, or just those created since the last scan.

TODO parallelise this code

Specified by:

scan in class FinalizableProcessor

Parameters:

nursery - Scan only the newly created references

trace - the thread local trace element.

getReady

public Object getReady()

Get an object to run finalize().

Returns:

The object to finalize()

count

public int count()

The number of entries in the table.

countReady

public int countReady()

The number of entries ready to be finalized.

freeReady

public int freeReady()

The number of entries ready to be finalized.

getProcessor

public static FinalizableProcessor getProcessor()

Get the singleton

addCandidate

public static void addCandidate(Object object)

Add a finalization candidate.

Parameters:

object - The object with a finalizer.

getForFinalize

public static Object getForFinalize()

Get an object to call the finalize() method on it.

countReadyForFinalize

public static int countReadyForFinalize()

The number of objects waiting for finalize() calls.