avrora.sim.util
Class TransactionalList

java.lang.Object
  avrora.sim.util.TransactionalList

Direct Known Subclasses:

MulticastExceptionWatch, MulticastFSMProbe, MulticastInterruptProbe, MulticastIORWatch, MulticastProbe, MulticastWatch

public class TransactionalList

extends java.lang.Object

The TransactionalList class implements a list of objects that has the special property that it can be frozen temporarily and unfrozen. During the time that the list is "frozen", requests to add or remove objects from the list are queued. Upon unfreezing, the queue of requests is processed in order, and then the list is free to have objects added and removed again.

Nested Class Summary

protected static class

TransactionalList.Link The Link class is used internally to represent links for the list of objects and updates.

Field Summary

protected TransactionalList.Link	head
protected int	nesting
protected TransactionalList.Link	tail
protected TransactionalList.Link	transHead
protected TransactionalList.Link	transTail

Constructor Summary

TransactionalList()

Method Summary

void	add(java.lang.Object b) The add() method allows another probe to be inserted into the multicast set.
void	beginTransaction() The beginTransaction() method freezes this list so that further requests for updates (such as to add or remove objects) are queued until the transaction is completed, which is triggered by a called to endTransaction().
void	endTransaction() The endTransaction() method unlocks this list from the transaction and will process any queued adds or removes in order from the time the beginTransaction() method was called.
boolean	isEmpty() The isEmpty() method tests whether this list is empty.
void	remove(java.lang.Object o) The remove method removes a probe from the multicast set.

Methods inherited from class java.lang.Object

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

Field Detail

head

protected TransactionalList.Link head

tail

protected TransactionalList.Link tail

transHead

protected TransactionalList.Link transHead

transTail

protected TransactionalList.Link transTail

nesting

protected int nesting

Constructor Detail

TransactionalList

public TransactionalList()

Method Detail

add

public void add(java.lang.Object b)

The add() method allows another probe to be inserted into the multicast set. It will be inserted at the end of the list of current probes and will therefore fire after any probes already in the multicast set.

Parameters:

b - the probe to insert

remove

public void remove(java.lang.Object o)

The remove method removes a probe from the multicast set. The order of the remaining probes is not changed. The comparison used is reference equality, not the .equals() method.

Parameters:

o - the probe to remove

isEmpty

public boolean isEmpty()

The isEmpty() method tests whether this list is empty. If this list is currently in a transaction (frozen), this method does not consider pending updates to the list.

Returns:

true if there are no objects in this list; false otherwise

beginTransaction

public void beginTransaction()

The beginTransaction() method freezes this list so that further requests for updates (such as to add or remove objects) are queued until the transaction is completed, which is triggered by a called to endTransaction(). When this method is called, all pending requests to add or remove objects are processed in order.

endTransaction

public void endTransaction()

The endTransaction() method unlocks this list from the transaction and will process any queued adds or removes in order from the time the beginTransaction() method was called.