alma.acs.component

Interface ComponentLifecycle

All Known Subinterfaces:

StatefulComponentLifecycle, StatelessComponentLifecycle

All Known Implementing Classes:

BasePerfCompImpl, BlobberImpl, CharacteristicComponentImpl, ComplexBACIComponentImpl, ComponentImplBase, ComponentWithXmlOffshootImpl, ControllerImpl, CorbaNotifyBaseImpl, CorbaNotifyConsumerImpl, CorbaNotifySupplierImpl, CounterConsumerImpl, CounterSupplierImpl, ErrorComponentImpl, ErrorSystemImpl, ErrTestComponentImpl, EventConsumerImpl, EventSupplierImpl, HelloDemoImpl, LampAccessImpl, LampCallbackImpl, LogStressImpl, LogTestComponent, MasterComponentImplBase, MethodTestComponentImpl, MFImpl, Mount1Impl, Mount6Impl, NCReceiverImpl, SimpleBACIComponentImpl, SimpleBACIComponentImpl, StatelessComponentImplBase, SupplierTestComponent, TestLifeCycleCompImpl, TestLogLevelsCompImpl, XmlComponentImpl, XmlFileStoreAlarmImpl, XmlFileStoreLoggerImpl

public interface ComponentLifecycle

Interface that every component has to implement.

The methods are used by the container to start and stop the component, that is, to manage its lifecycle.

Note that the constructor of the component implementation should be very small, preferably empty. Use the methods initialize(ContainerServices) and execute() instead.

TODOs:

• we still have to think about the exception mechanism.
• new methods for more advanced behavior, e.g. restarting a component transparently for its client, will be added later. Their definition requires more analysis, and their implementation will also require changes to the ACS Manager etc.

Author:

hsommer

Method Summary

Modifier and Type	Method and Description
void	aboutToAbort() Called when due to some error condition the component is about to be forcefully removed some unknown amount of time later (usually not very much...).
void	cleanUp() Called after the last functional call to the component has finished.
void	execute() Called after initialize(ContainerServices) to tell the component that it has to be ready to accept incoming functional calls any time.
void	initialize(ContainerServices containerServices) Called to give the component time to initialize itself.

Method Detail

initialize

void initialize(ContainerServices containerServices)
         throws ComponentLifecycleException

Called to give the component time to initialize itself. For instance, the component could retrieve connections, read in configuration files/parameters, build up in-memory tables, ...

Called before execute(). In fact, this method might be called quite some time before functional requests can be sent to the component.

Must be implemented as a synchronous (blocking) call.

Parameters:

containerServices - callback object for services provided by the container

Throws:

ComponentLifecycleException

execute

void execute()
      throws ComponentLifecycleException

Called after initialize(ContainerServices) to tell the component that it has to be ready to accept incoming functional calls any time.

Examples:

• last-minute initializations for which initialize seemed too early
• component could start actions which aren't triggered by any functional call, e.g. the Scheduler could start to rank SBs in a separate thread.

Must be implemented as a synchronous (blocking) call (can spawn threads though).

Throws:

ComponentLifecycleException

cleanUp

void cleanUp()
      throws AcsJComponentCleanUpEx

Called after the last functional call to the component has finished. The component should then orderly release resources etc.

Throws:

AcsJComponentCleanUpEx

aboutToAbort

void aboutToAbort()

Called when due to some error condition the component is about to be forcefully removed some unknown amount of time later (usually not very much...).

The component should make an effort to die as neatly as possible.

Because of its urgency, this method will be called asynchronously to the execution of any other method of the component.