Thread-death notifier

Describes the thread-death notifier.

Thread-death notifiers allow threads to be notified when another thread dies.

A thread-death notifier is a Kernel object and, as such, is managed by the Kernel. Access to a thread-death notifier is through an Rundertaker handle.

The thread-death notifier service is an asynchronous service provider and is intended to be part of an active object.