org.objectweb.fractal.julia.control.lifecycle
Interface LifeCycleCoordinator

All Superinterfaces:

LifeCycleController

All Known Implementing Classes:

BasicLifeCycleControllerMixin, BasicLifeCycleCoordinatorMixin, ContainerLifeCycleMixin, LoggerLifeCycleMixin, OptimizedLifeCycleControllerMixin

public interface LifeCycleCoordinator

extends LifeCycleController

An extended LifeCycleController interface. This interface is used to stop several components simultaneously, in order to avoid the deadlocks that can occur when several components are stopped one by one (for example, if a component C is stopped after a component S, and if a thread T is executing a method m1 in C which calls a method m2 in S, then T can be blocked in m2 just after S is stopped but before C is stopped, in which case C can not be stopped, and a deadlock occurs).

Field Summary

Fields inherited from interface org.objectweb.fractal.api.control.LifeCycleController

STARTED, STOPPED

Method Summary

boolean	fcActivated(LifeCycleCoordinator component) Notifies this component that the given component is about to become active.
void	fcInactivated(LifeCycleCoordinator component) Notifies this component that the given component has become inactive.
boolean	setFcStarted() Sets the state of this component, but not of its sub components, to STARTED.
boolean	setFcStopped() Sets the state of this component, but not of its sub components, to STOPPED.
void	setFcStopping(LifeCycleCoordinator coordinator) Sets the state of this component, but not of its sub components, to "STOPPING".

Methods inherited from interface org.objectweb.fractal.api.control.LifeCycleController

getFcState, startFc, stopFc

Method Detail

setFcStarted

public boolean setFcStarted()
                     throws IllegalLifeCycleException

Sets the state of this component, but not of its sub components, to STARTED. Because of component sharing, the startFc method cannot be implemented by just calling itself recursively on the sub components of this componets (otherwise some sub components may be started several times). Hence this method.

Returns:

true if the execution state has changed, or false if it had already the STARTED value.

Throws:

IllegalLifeCycleException - if a problem occurs.

setFcStopping

public void setFcStopping(LifeCycleCoordinator coordinator)
                   throws IllegalLifeCycleException

Sets the state of this component, but not of its sub components, to "STOPPING". After this method has been called, and while the setFcStopped has not been called, this component must notify the given coordinator when it becomes inactive, and when it is about to become active, with the fcInactivated and fcActivated methods.
Note: the "STOPPING" state is an internal state that is not visible from the outside. Indeed, in this state, the getFcState method should return STARTED, as the component is not yet stopped.

Parameters:

coordinator - the coordinator that must be notified when this component becomes inactive, and when it is about to become active.

Throws:

IllegalLifeCycleException - if a problem occurs.

setFcStopped

public boolean setFcStopped()
                     throws IllegalLifeCycleException

Sets the state of this component, but not of its sub components, to STOPPED. Because of component sharing, the stopFc method cannot be implemented by just calling itself recursively on the sub components of this componets (otherwise some sub components may be stopped several times). Hence this method.

Returns:

true if the execution state has changed, or false if it had already the STOPPED value.

Throws:

IllegalLifeCycleException - if a problem occurs.

fcActivated

public boolean fcActivated(LifeCycleCoordinator component)

Notifies this component that the given component is about to become active. This method must be called by a component when the following conditions are met:

• the component is stopping, i.e., its setFcStopping method has been called.
• the component is not yet stopped, i.e., its setFcStopped method has not been called yet.
• the component is currently inactive, but a new activity is about to start in this component.

Parameters:

component - the LifeCycleCoordinator interface of a component that is about to become active.

Returns:

true if the given component can become active, or false if the new activity must be delayed until the component is restarted.

fcInactivated

public void fcInactivated(LifeCycleCoordinator component)

Notifies this component that the given component has become inactive. This method must be called by a component when the following conditions are met:

• the component is stopping, i.e., its setFcStopping method has been called.
• the component is not yet stopped, i.e., its setFcStopped method has not been called yet.
• the component has become inactive.

Parameters:

component - the LifeCycleCoordinator interface of a component that has become inactive.