com.oracle.svm.core.genscavenge

Class YoungGeneration

java.lang.Object

com.oracle.svm.core.genscavenge.Generation

com.oracle.svm.core.genscavenge.YoungGeneration

public class YoungGeneration
extends Generation

A Young Generation has one space, for ordinary objects.

Field Summary

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

name

Method Summary

Modifier and Type	Method and Description
Space	getSpace() Space access method.
protected boolean	isValidSpace(Space thatSpace) Returns true if the space is a valid Space in this generation, else false.
protected Object	promoteObject(Object original, org.graalvm.word.Pointer objRef, int innerOffset, boolean compressed) Promote an Object to this Generation, either by HeapChunk motion or copying.
Log	report(Log log, boolean traceHeapChunks) Report some statistics about the Generation to a Log.
void	tearDown() Return all allocated virtual memory chunks to HeapChunkProvider.
protected boolean	verify(HeapVerifier.Occasion occasion)
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.

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

getSpace

public final Space getSpace()

Space access method. This method is final because it is called (transitively) from the allocation snippets.

promoteObject

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

Description copied from class: Generation

Promote an Object to this Generation, either by HeapChunk motion or copying. If the original is copied, a forwarding pointer to the new Object is left in place of the original Object. This turns an Object from white to grey: the object is in this Generation, but has not yet had its interior pointers visited.

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:

isValidSpace

protected boolean isValidSpace(Space thatSpace)

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