DoublyLinkedList (Jikes RVM API)

java.lang.Object
- org.mmtk.utility.DoublyLinkedList

```
public final class DoublyLinkedList
extends Object
```
FIXME This class must be re-written as it makes the assumption that the implementation language (Java) and the language being implemented are the same. This is true in the case of Jikes RVM, but it is not true for any VM implementing a language other than Java.
Each instance of this class is a doubly-linked list, in which each item or node is a piece of memory. The first two words of each node contains the forward and backward links. The third word contains the treadmill. The remaining portion is the payload.
The treadmill object itself must not be moved.
Access to the instances may be synchronized depending on the constructor argument.

Field Summary

Fields
Modifier and Type	Field and Description
`private Address`	`head`
`private static Offset`	`HEADER_SIZE`
`private Lock`	`lock`
`private int`	`logGranularity`
`private static Offset`	`NEXT_OFFSET`
`private static Word`	`nodeMask`
`private static Offset`	`PREV_OFFSET`

Constructor Summary

Constructors
Constructor and Description

DoublyLinkedList(int logGranularity, boolean shared)

Constructors
Constructor and Description
`DoublyLinkedList(int logGranularity, boolean shared)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(Address node)`
`(package private) void`	`gcspyGatherData(AbstractDriver driver)` Gather data for GCSpy
`Address`	`getHead()`
`Address`	`getNext(Address node)`
`static int`	`headerSize()`
`boolean`	`isEmpty()`
`boolean`	`isMember(Address node)` Return true if a cell is on a given treadmill
`boolean`	`isNode(Address node)`
`static Address`	`midPayloadToNode(Address payload)`
`static Address`	`nodeToPayload(Address node)`
`Address`	`pop()`
`void`	`remove(Address node)`
`void`	`show()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

head
```
private Address head
```

lock
```
private final Lock lock
```

logGranularity
```
private final int logGranularity
```

PREV_OFFSET

private static final Offset PREV_OFFSET

NEXT_OFFSET
```
private static Offset NEXT_OFFSET
```

HEADER_SIZE
```
private static Offset HEADER_SIZE
```

nodeMask
```
private static final Word nodeMask
```

Constructor Detail
- DoublyLinkedList
```
public DoublyLinkedList(int logGranularity,
                        boolean shared)
```
  Parameters:
  
  logGranularity - TODO needs documentation
  
  shared - whether the instance will be shared between threads

Method Detail

headerSize
```
public static int headerSize()
```

isNode
```
public boolean isNode(Address node)
```

nodeToPayload

public static Address nodeToPayload(Address node)

midPayloadToNode

public static Address midPayloadToNode(Address payload)

add
```
public void add(Address node)
```

remove
```
public void remove(Address node)
```

getHead
```
public Address getHead()
```

getNext
```
public Address getNext(Address node)
```

pop
```
public Address pop()
```

isEmpty
```
public boolean isEmpty()
```

isMember
```
public boolean isMember(Address node)
```
Return true if a cell is on a given treadmill

Parameters:

node - The cell being searched for

Returns:

true if the cell is found on the treadmill

show
```
public void show()
```

gcspyGatherData
```
void gcspyGatherData(AbstractDriver driver)
```
Gather data for GCSpy

Parameters:

driver - the GCSpy space driver

Class DoublyLinkedList

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

head

lock

logGranularity

PREV_OFFSET

NEXT_OFFSET

HEADER_SIZE

nodeMask

Constructor Detail

DoublyLinkedList

Method Detail

headerSize

isNode

nodeToPayload

midPayloadToNode

add

remove

getHead

getNext

pop

isEmpty

isMember

show

gcspyGatherData