public abstract Class IteratingNestedCallback

This specialized callback is used when breaking up an asynchronous task into smaller asynchronous tasks. A typical pattern is that a successful callback is used to schedule the next sub task, but if that task completes quickly and uses the calling thread to callback the success notification, this can result in a growing stack depth.

To avoid this issue, this callback uses an AtomicBoolean to note if the success callback has been called during the processing of a sub task, and if so then the processing iterates rather than recurses.

This callback is passed to the asynchronous handling of each sub task and a call the succeeded() on this call back represents completion of the subtask. Only once all the subtasks are completed is the Callback#succeeded() method called on the Callback instance passed the the IteratingNestedCallback(Callback) constructor.