com.oracle.svm.core.heap

Class AllocationFreeList.Element<T extends AllocationFreeList.Element<T>>

java.lang.Object

com.oracle.svm.core.heap.AllocationFreeList.Element<T>

Direct Known Subclasses:

CollectionWatcher, HeapVerifier.MemoryChecker

Enclosing class:

AllocationFreeList<T extends AllocationFreeList.Element<T>>

public static class AllocationFreeList.Element<T extends AllocationFreeList.Element<T>>
extends Object

An element of a AllocationFreeList has slots for the next element in the list, so singly-linked lists can be assembled without allocation. The lifecycle of an Element is:

• Creation: next: null enabled: false enlisted: false.
• Prepended: next: oldHead enabled: true enlisted: true.
• Removed: next: next enabled: false enlisted: true.

An Element can be put on a list exactly once, because "enlisted" only goes from false to true but not back.

TODO: If I wanted to be able to move an Element from one list to another, the "enlisted" field could point to the old list the element was on, and I could remove it from the old list, scrub the old list, reset "enlisted", and then prepend the element to the new list. Since the feature is not needed, it is not implemented.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Element() Constructor for subclasses.

Method Summary

Modifier and Type	Method and Description
boolean	getHasBeenOnList() Has this element ever been on a list?
T	getNextElement() Get the next enabled element of the list.
Object	getNextObject() For detecting errors: Get the next element as an Object so there is no type checking.
void	removeElement() Logically remove this element from the list.
T	testingBackDoorGetNextElement()
boolean	testingBackDoorIsEnabled()

Methods inherited from class java.lang.Object

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

Constructor Detail

Element

protected Element()

Constructor for subclasses. This might not get called so it can not do anything interesting.

Method Detail

getNextElement

public T getNextElement()

Get the next enabled element of the list.

getNextObject

public Object getNextObject()

For detecting errors: Get the next element as an Object so there is no type checking.

removeElement

public void removeElement()

Logically remove this element from the list.

getHasBeenOnList

public boolean getHasBeenOnList()

Has this element ever been on a list?

testingBackDoorIsEnabled

public boolean testingBackDoorIsEnabled()

testingBackDoorGetNextElement

public T testingBackDoorGetNextElement()