# Package org.apache.felix.ipojo.extender.queue

Interface Summary
Callback<T>: When submitting a processing job, a callback object can be passed to the submission process.
Job<T>: Represents a task that can be executed by the `QueueService`.
JobInfo: Interface to retrieve information about the job execution.
QueueListener: A `QueueListener` provides queue management information to external entities: Job submission Job execution Job result (success or failure) Implementer of this interface should not block as the invocation is done synchronously.
QueueService: Definition of the queue service.