Notification Services Overview

Purpose

Provides miscellaneous low-level services for notifying programs of environment changes and of thread deaths, and for putting simple messages on screen.

Description

The API has three key concepts: change notifier, thread-death notifier, and simple screen output service.

Change notifier

The change notifier signals the requesting thread's request semaphore when a change in the environment occurs, such as a switch in locale, or system time being reset.

The change notifier interface is provided by RChangeNotifier.

Note that the Environment Change Notifier API provides the same service, wrapped in an active object.

Thread-death notifier

The thread-death notifier signals the requesting thread's request semaphore when a specified other thread terminates.

The thread-death notifier interface is provided by RUndertaker.

Simple screen output service

The simple screen output service allows either a single line message or a simple dialog box to be displayed on the screen. It is typically used for debug messages.

The simple screen output service interface is provided by RNotifier, which also provides access to the UI-specific plug-in notifiers, via the Extended Notifier Framework.