com.ibm.wala.fixpoint

Class AbstractVariable<T extends AbstractVariable<T>>

java.lang.Object

com.ibm.wala.util.graph.impl.NodeWithNumber

com.ibm.wala.fixpoint.AbstractVariable<T>

All Implemented Interfaces:

IVariable<T>, INodeWithNumber

Direct Known Subclasses:

BitVectorVariable, BooleanVariable, IntSetVariable

public abstract class AbstractVariable<T extends AbstractVariable<T>>
extends NodeWithNumber
implements IVariable<T>

Represents a single variable in a fixed-point system.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractVariable()

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
int	getOrderNumber() Variables must allow the solver implementation to get/set an order number, which the solver uses to control evaluation order.
int	hashCode()
static int	nextHash() I know this is theoretically bad.
void	setOrderNumber(int orderNumber) Variables must allow the solver implementation to get/set an order number, which the solver uses to control evaluation order.

Methods inherited from class com.ibm.wala.util.graph.impl.NodeWithNumber

getGraphNodeId, setGraphNodeId

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.ibm.wala.fixpoint.IVariable

copyState

Methods inherited from interface com.ibm.wala.util.graph.INodeWithNumber

getGraphNodeId, setGraphNodeId

Constructor Detail

AbstractVariable

protected AbstractVariable()

Method Detail

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

nextHash

public static int nextHash()

I know this is theoretically bad. However,

• we need this to be extremely fast .. it's in the inner loop of lots of stuff.
• these objects will probably only be hashed with each other AbstractVariables, in which case incrementing hash codes is OK.
• we want determinism, so we don't want to rely on System.identityHashCode

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

getOrderNumber

public int getOrderNumber()

Description copied from interface: IVariable

Variables must allow the solver implementation to get/set an order number, which the solver uses to control evaluation order.

It might be cleaner to hold this on the side, but we cannot tolerate any extra space. TODO: consider moving this functionality to a subinterface?

Specified by:

getOrderNumber in interface IVariable<T extends AbstractVariable<T>>

Returns:

a number used to order equation evaluation

setOrderNumber

public void setOrderNumber(int orderNumber)

Description copied from interface: IVariable

Variables must allow the solver implementation to get/set an order number, which the solver uses to control evaluation order.

It might be cleaner to hold this on the side, but we cannot tolerate any extra space. TODO: consider moving this functionality to a subinterface?

Specified by:

setOrderNumber in interface IVariable<T extends AbstractVariable<T>>