com.sun.corba.se.impl.orbutil.fsm

Class StateEngineImpl

java.lang.Object

com.sun.corba.se.impl.orbutil.fsm.StateEngineImpl

All Implemented Interfaces:

StateEngine

public class StateEngineImpl
extends Object
implements StateEngine

Encodes the state transition function for a finite state machine.

Author:

Ken Cavanaugh

Constructor Summary

Constructors

Constructor and Description
StateEngineImpl()

Method Summary

Modifier and Type	Method and Description
StateEngine	add(State oldState, Input input, Action action, State newState) Add a transition with a guard that always evaluates to true.
StateEngine	add(State oldState, Input input, Guard guard, Action action, State newState) Add a new transition (old,in,guard,act,new) to the state engine.
void	doIt(FSM fsm, Input in, boolean debug)
void	done() Called after all transitions have been added to the state engine.
FSM	makeFSM(State startState) Create an instance of a FSM that uses this state engine.
StateEngine	setDefault(State oldState) Euaivalent to setDefault( oldState, oldState )
StateEngine	setDefault(State oldState, Action action, State newState) Set the default transition and action for a state.
StateEngine	setDefault(State oldState, State newState) Equivalent to setDefault( oldState, act, newState ) where act is an action that does nothing.
void	setDefaultAction(Action act) Set the default action used in this state engine.

Methods inherited from class java.lang.Object

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

Constructor Detail

StateEngineImpl

public StateEngineImpl()

Method Detail

add

public StateEngine add(State oldState,
                       Input input,
                       Guard guard,
                       Action action,
                       State newState)
                throws IllegalArgumentException,
                       IllegalStateException

Description copied from interface: StateEngine

Add a new transition (old,in,guard,act,new) to the state engine. Multiple calls to add with the same old and in are permitted, in which case only a transition in which the guard evaluates to true will be taken. If no such transition is enabled, a default will be taken. If more than one transition is enabled, one will be chosen arbitrarily. This method can only be called before done(). An attempt to call it after done() results in an IllegalStateException.

Specified by:

add in interface StateEngine

Throws:

IllegalArgumentException

IllegalStateException

add

public StateEngine add(State oldState,
                       Input input,
                       Action action,
                       State newState)
                throws IllegalArgumentException,
                       IllegalStateException

Description copied from interface: StateEngine

Add a transition with a guard that always evaluates to true.

Specified by:

add in interface StateEngine

Throws:

IllegalArgumentException

IllegalStateException

setDefault

public StateEngine setDefault(State oldState,
                              Action action,
                              State newState)
                       throws IllegalArgumentException,
                              IllegalStateException

Description copied from interface: StateEngine

Set the default transition and action for a state. This transition will be used if no more specific transition was defined for the actual input. Repeated calls to this method simply change the default. This method can only be called before done(). An attempt to call it after done() results in an IllegalStateException.

Specified by:

setDefault in interface StateEngine

Throws:

IllegalArgumentException

IllegalStateException

setDefault

public StateEngine setDefault(State oldState,
                              State newState)
                       throws IllegalArgumentException,
                              IllegalStateException

Description copied from interface: StateEngine

Equivalent to setDefault( oldState, act, newState ) where act is an action that does nothing.

Specified by:

setDefault in interface StateEngine

Throws:

IllegalArgumentException

IllegalStateException

setDefault

public StateEngine setDefault(State oldState)
                       throws IllegalArgumentException,
                              IllegalStateException

Description copied from interface: StateEngine

Euaivalent to setDefault( oldState, oldState )

Specified by:

setDefault in interface StateEngine

Throws:

IllegalArgumentException

IllegalStateException

done

public void done()
          throws IllegalStateException

Description copied from interface: StateEngine

Called after all transitions have been added to the state engine. This provides an opportunity for the implementation to optimize its representation before the state engine is used. This method may only be called once. An attempt to call it more than once results in an IllegalStateException.

Specified by:

done in interface StateEngine

Throws:

IllegalStateException

setDefaultAction

public void setDefaultAction(Action act)
                      throws IllegalStateException

Description copied from interface: StateEngine

Set the default action used in this state engine. This is the action that is called whenever there is no applicable transition. Normally this would simply flag an error. This method can only be called before done(). An attempt to call it after done() results in an IllegalStateException.

Specified by:

setDefaultAction in interface StateEngine

Throws:

IllegalStateException

doIt

public void doIt(FSM fsm,
                 Input in,
                 boolean debug)

makeFSM

public FSM makeFSM(State startState)
            throws IllegalStateException

Description copied from interface: StateEngine

Create an instance of a FSM that uses this state engine. The initial state of the FSM will be the stateState specified here. This method can only be called after done(). An attempt to call it before done results in an IllegalStateException.

Specified by:

makeFSM in interface StateEngine

Throws:

IllegalStateException