org.eclipse.emf.henshin.statespace.impl
Class BasicStateSpaceManager

java.lang.Object
  org.eclipse.emf.henshin.statespace.impl.StateSpaceIndexImpl
      org.eclipse.emf.henshin.statespace.impl.BasicStateSpaceManager

All Implemented Interfaces:

StateSpaceIndex, StateSpaceManager

Direct Known Subclasses:

ParallelStateSpaceManager, ProfilingStateSpaceManager

public class BasicStateSpaceManager
extends StateSpaceIndexImpl
implements StateSpaceManager

Basic StateSpaceManager implementation.

Field Summary

protected Stack<StateExplorer>	explorers State exploration helpers.
protected boolean	ignoreDuplicateTransitions Flag indicating whether duplicate transitions with the same label should be ignored.
protected int	maxStateDistance Maximum state distance.
protected StateDistanceMonitor	stateDistanceMonitor State distance monitor.
protected Object	stateSpaceLock A lock used when accessing the state space.

Fields inherited from interface org.eclipse.emf.henshin.statespace.StateSpaceManager

DEBUG_ENFORCE_DETERMINISM

Constructor Summary

BasicStateSpaceManager(StateSpace stateSpace)
Default constructor.

Method Summary

protected StateExplorer	acquireExplorer()
void	clearCache() Clear all caches of the state space index.
State	createInitialState(Model model) Create a new initial state to the state space.
protected State	createOpenState(Model model, int hash, State derivedFrom, int[] location) Create a new open state in the state space.
protected Model	deriveModel(State state, boolean fromInitial)
protected List<State>	exploreState(State state, boolean generateLocation) Explore a given state.
List<State>	exploreStates(List<State> states, boolean generateLocation) Explore a state.
protected State	findState(Model model, int hashCode, Collection<State> states)
int	getNumThreads() Get the number of threads used by this state manager.
int	getStateDistance(State state) Get the distance of a state to an initial state.
protected boolean	isOpen(State state)
List<State>	mergeTerminalStates() Merge all terminal states
protected void	refreshHelpers()
protected void	releaseExplorer(StateExplorer explorer)
List<State>	removeState(State state) Remove a state from the state space.
void	resetStateSpace(boolean removeInitial) Reset the state space managed by this instance.
protected static int[]	shiftedLocation(State base, int index)
void	shutdown() Shutdown this state space manager.

Methods inherited from class org.eclipse.emf.henshin.statespace.impl.StateSpaceIndexImpl

addToCache, addToIndex, getCachedModel, getModel, getState, getState, getStateSpace, removeFromIndex, resetIndex

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.emf.henshin.statespace.StateSpaceIndex

getCachedModel, getModel, getState, getStateSpace

Field Detail

explorers

protected final Stack<StateExplorer> explorers

State exploration helpers.

stateSpaceLock

protected final Object stateSpaceLock

A lock used when accessing the state space.

stateDistanceMonitor

protected StateDistanceMonitor stateDistanceMonitor

State distance monitor.

maxStateDistance

protected int maxStateDistance

Maximum state distance.

ignoreDuplicateTransitions

protected boolean ignoreDuplicateTransitions

Flag indicating whether duplicate transitions with the same label should be ignored.

Constructor Detail

BasicStateSpaceManager

public BasicStateSpaceManager(StateSpace stateSpace)

Default constructor.

Parameters:

stateSpace - State space.

Method Detail

refreshHelpers

protected void refreshHelpers()

isOpen

protected boolean isOpen(State state)
                  throws StateSpaceException

Throws:

StateSpaceException

createOpenState

protected final State createOpenState(Model model,
                                      int hash,
                                      State derivedFrom,
                                      int[] location)

Create a new open state in the state space. Warning: this does not check if an equivalent state exists already or whether the hash code is incorrect.

Parameters:

model - Its model.

hash - The model's hash code.

Returns:

The newly created state.

createInitialState

public final State createInitialState(Model model)
                               throws StateSpaceException

Description copied from interface: StateSpaceManager

Create a new initial state to the state space. This throws a runtime exception if the state is not contained in a resource. If there is already a state for it, it is returned instead.

Specified by:

createInitialState in interface StateSpaceManager

Parameters:

model - Model of the initial state.

Returns:

The newly created state.

Throws:

StateSpaceException - If the state space contains errors.

removeState

public final List<State> removeState(State state)
                              throws StateSpaceException

Description copied from interface: StateSpaceManager

Remove a state from the state space. Unreachable states are automatically removed afterwards and the open-attributes are updated.

Specified by:

removeState in interface StateSpaceManager

Parameters:

state - State to be removed.

Returns:

List of removed states.

Throws:

StateSpaceException - If the state space contains errors.

mergeTerminalStates

public List<State> mergeTerminalStates()
                                throws StateSpaceException

Description copied from interface: StateSpaceManager

Merge all terminal states

Specified by:

mergeTerminalStates in interface StateSpaceManager

Returns:

List of removed states.

Throws:

StateSpaceException - If the state space contains errors.

resetStateSpace

public final void resetStateSpace(boolean removeInitial)
                           throws StateSpaceException

Description copied from interface: StateSpaceManager

Reset the state space managed by this instance. This removes all derived states and all transitions.

Specified by:

resetStateSpace in interface StateSpaceManager

Throws:

StateSpaceException - On errors.

findState

protected State findState(Model model,
                          int hashCode,
                          Collection<State> states)
                   throws StateSpaceException

Throws:

StateSpaceException

getStateDistance

public int getStateDistance(State state)

Get the distance of a state to an initial state. This returns the correct distance only if the maximum state distance of the state space is positive. Otherwise the distance is not relevant and therefore not stored.

Specified by:

getStateDistance in interface StateSpaceManager

Parameters:

state - The state.

Returns:

Its distance from an initial state, or -1 if not available.

deriveModel

protected Model deriveModel(State state,
                            boolean fromInitial)
                     throws StateSpaceException

Overrides:

deriveModel in class StateSpaceIndexImpl

Throws:

StateSpaceException

exploreStates

public List<State> exploreStates(List<State> states,
                                 boolean generateLocation)
                          throws StateSpaceException

Description copied from interface: StateSpaceManager

Explore a state. This computes all outgoing transitions and their target states and adds them to the state space if they do not exist yet.

Specified by:

exploreStates in interface StateSpaceManager

Returns:

List of newly created successor states.

Throws:

StateSpaceException - If the state space contains errors.

exploreState

protected List<State> exploreState(State state,
                                   boolean generateLocation)
                            throws StateSpaceException

Explore a given state.

Parameters:

state - State to be explored.

generateLocation - Whether to generate locations for the new state.

Returns:

List of newly created successor states.

Throws:

StateSpaceException - On errors.

acquireExplorer

protected StateExplorer acquireExplorer()

releaseExplorer

protected void releaseExplorer(StateExplorer explorer)

shiftedLocation

protected static int[] shiftedLocation(State base,
                                       int index)

getNumThreads

public int getNumThreads()

Description copied from interface: StateSpaceManager

Get the number of threads used by this state manager.

Specified by:

getNumThreads in interface StateSpaceManager

Returns:

The number of used threads.

shutdown

public void shutdown()

Description copied from interface: StateSpaceManager

Shutdown this state space manager.

Specified by:

shutdown in interface StateSpaceManager

clearCache

public void clearCache()

Description copied from interface: StateSpaceIndex

Clear all caches of the state space index.

Specified by:

clearCache in interface StateSpaceIndex

Overrides:

clearCache in class StateSpaceIndexImpl