Package org.jboss.msc.service

The service container implementation itself.

See: Description

Interface Summary

Interface	Description
BatchServiceTarget	A ServiceTarget that provides removal of all services installed so far.
LifecycleContext	A context object for lifecycle events.
MultipleRemoveListener.Callback<T>	A generalized callback for when all services are removed.
Service<T>	A service is a thing which can be started and stopped.
ServiceActivator	A service activator which contributes services to a batch.
ServiceActivatorContext	Context provided to ServiceActivator instances at execution time.
ServiceBuilder<T>	A builder for an individual service in a ServiceTarget.
ServiceContainer	A service container which manages a set of running services.
ServiceContainer.TerminateListener	A listener for notification of container shutdown.
ServiceController<S>	A controller for a single service instance.
ServiceListener<S>	Deprecated Service listeners are not encouraged for general user use.
ServiceRegistry	A service registry.
ServiceTarget	The target of ServiceBuilder installations.
StartContext	The start lifecycle context.
StopContext	The stop lifecycle context.

Class Summary

Class	Description
AbstractService<T>	An abstract service class which provides default implementations.
AbstractServiceListener<S>	An abstract implementation of a service listener whose methods do nothing.
DelegatingServiceBuilder<T>	A service builder which delegates to another service builder.
DelegatingServiceContainer	A delegating container for things which depend on a service container rather than a specific target or registry instance.
DelegatingServiceRegistry	An "insulated" view of a service registry which prevents access to other public methods on the delegate registry object.
DelegatingServiceTarget	An "insulated" view of a service target which prevents access to other public methods on the delegate target object.
MultipleRemoveListener<T>	A service listener which calls a callback once all of the services it was attached to have been removed.
ServiceActivatorContextImpl	A simple service activator context implementation.
ServiceContainer.Factory	The factory class for service containers.
ServiceContainer.TerminateListener.Info	Container shutdown information.
ServiceName	Service name class.
ServiceNameMapper<V>	A mapper for service names which allows a service name or pattern to be correlated with a value.
ServiceUtils	A utility class for service actions.
StabilityMonitor	A stability detection utility.
StabilityStatistics	A stability monitor statistics.
TimingServiceListener	A service listener which times service start.
ValueInjection<T>	An injection of a source value into a target injector.
ValueInjectionService<T>	A service which propagates a value from a dependency.
ValueService<T>	A service which returns the provided value, which is evaluated once per service start.

Enum Summary

Enum	Description
ServiceBuilder.DependencyType	The dependency type.
ServiceController.Mode	The controller mode for a service.
ServiceController.State	A possible state for a service controller.
ServiceController.Substate	A fine-grained substate of the more general basic controller ServiceController.States.
ServiceController.Transition	A transition from one substate to another.

Exception Summary

Exception	Description
CircularDependencyException	Exception used to indicate there was a circular dependency discovered during resolution.
DuplicateServiceException	An exception which is thrown when the given service is already registered.
ServiceNotFoundException	Exception which is thrown when a required service is not found in the registry.
ServiceRegistryException	Base Exception class used for service registry issues.
StartException	A start exception, thrown when a service fails to start.

Package org.jboss.msc.service Description

The service container implementation itself. The service container is what coordinates the registry of services and manages their installation and execution. To create a service container, see ServiceContainer.Factory.create(). To create services, implement the Service interface.

Individual service instances are controlled using the ServiceController interface. Service controllers follow this strict internal state machine:

The green boxes represent states; the red boxes below them represent possible transitions. The "When:" condition must be satisfied before a transition is taken; if it is, then the asynchronous tasks listed under "Tasks:" are executed.

The variables are what determine when a transition may occur; any time a variable is changed, the conditions are checked to see if a transition can occur. The variables are as follows:

• A: The number of currently running asynchronous tasks.
• R: The number of running children (dependents).
• D: The number of "demands" from children, used to trigger the start of ON_DEMAND services. If greater than zero, a single "demand" is propagated to the dependency set (parents) of this service.
• U: The count, from zero, representing the desire of the service to be "up". Only services with a positive "up" count will start.
• X: The exception produced by the service start() method, if any.
• MODE: The controller start mode. Values can be one of:
  • ACTIVE - attempt to start immediately, and request all parents (dependencies) to start as well by incrementing their "demand" count (D). Puts a load of +1 on U always.
  • PASSIVE - attempt to start immediately if all dependencies are up. Puts a load of +1 on U always.
  • ON_DEMAND - only start a service if demanded. Puts a load of +1 on U only if D is greater than zero.
  • NEVER - never start. The value of U is not affected and not considered. The value of D is disregarded; if D was greater than zero, then the existing "demand" on the dependency set (parents) is revoked and further "demands" are suppressed until this mode is left.
  • REMOVE - the same as NEVER; in addition, remove the service as soon as it is down. The mode may not be changed again after setting this mode.