com.oracle.svm.core.genscavenge

Class OldGeneration

java.lang.Object

com.oracle.svm.core.genscavenge.Generation

com.oracle.svm.core.genscavenge.OldGeneration

public class OldGeneration
extends Generation

An OldGeneration has three Spaces,

• fromSpace for existing objects,
• toSpace for newly-allocated or promoted objects, and
• pinnedSpace for pinned objects.

An OldGeneration also keeps a list of PinnedAllocators.

Field Summary

Fields inherited from class com.oracle.svm.core.genscavenge.Generation

name

Method Summary

Modifier and Type	Method and Description
Space	getFromSpace()
protected boolean	isValidSpace(Space space) Returns true if the space is a valid Space in this generation, else false.
protected void	prepareForPromotion()
Object	promoteObject(Object original, org.graalvm.word.Pointer objRef, int innerOffset, boolean compressed) Promote an Object to ToSpace if it is not already in ToSpace or PinnedToSpace.
protected void	promotePinnedAllocatorChunks(boolean completeCollection)
Log	report(Log log, boolean traceHeapChunks) Report some statistics about the Generation to a Log.
protected void	scanGreyObjects()
void	tearDown() Return all allocated virtual memory chunks to HeapChunkProvider.
protected boolean	verify(HeapVerifier.Occasion occasion)
protected void	walkDirtyObjects(ObjectVisitor visitor, boolean clean)
boolean	walkObjects(ObjectVisitor visitor) Walk the Objects in this Space, passing each to a Visitor.

Methods inherited from class com.oracle.svm.core.genscavenge.Generation

getName

Methods inherited from class java.lang.Object

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

Method Detail

tearDown

public final void tearDown()

Return all allocated virtual memory chunks to HeapChunkProvider.

walkObjects

public boolean walkObjects(ObjectVisitor visitor)

Description copied from class: Generation

Walk the Objects in this Space, passing each to a Visitor.

Specified by:

walkObjects in class Generation

Parameters:

visitor - An ObjectVisitor.

Returns:

True if all visits returned true, false otherwise.

promoteObject

public Object promoteObject(Object original,
                            org.graalvm.word.Pointer objRef,
                            int innerOffset,
                            boolean compressed)

Promote an Object to ToSpace if it is not already in ToSpace or PinnedToSpace.

Specified by:

promoteObject in class Generation

Parameters:

original - The original Object to be promoted.

objRef - The address of the reference to the original object.

innerOffset - The byte offset of a derived pointer from head of the original object. Subtract to get to the head of the original object, add to get back to a derived pointer inside the original object.

compressed - Whether object references are compressed.

Returns:

The promoted Object, either the original if promotion was done by HeapChunk motion, or a new Object if promotion was done by copying. For debugging GR-9912:

walkDirtyObjects

protected void walkDirtyObjects(ObjectVisitor visitor,
                                boolean clean)

prepareForPromotion

protected void prepareForPromotion()

scanGreyObjects

protected void scanGreyObjects()

promotePinnedAllocatorChunks

protected void promotePinnedAllocatorChunks(boolean completeCollection)

report

public Log report(Log log,
                  boolean traceHeapChunks)

Description copied from class: Generation

Report some statistics about the Generation to a Log.

Specified by:

report in class Generation

isValidSpace

protected boolean isValidSpace(Space space)

Description copied from class: Generation

Returns true if the space is a valid Space in this generation, else false.

Specified by:

isValidSpace in class Generation

verify

protected boolean verify(HeapVerifier.Occasion occasion)

Specified by:

verify in class Generation

getFromSpace

public Space getFromSpace()