equinox
dynamic plugins > registry life cycle

 
In the Eclipse (2.1) because the plugin registry is static, no events are really coming from it. In the dynamic plugins, as the registry will become dynamic to support the dynamic addition and removal of plugins (and so extensions and extension points), a notification mechanism needs to be created so plugins and other interested parties can react to those modifications. This event is accompanied by a registry delta that describes the changes. Plugins are notified in prerequisite order (i.e., prerequisites first). See also API extensions.

Notification mechanism
In order to put in place the notification mechanism, we took ideas from the Resource listener mechanism (IResourceListener, IResourceChangeEvent, IResourceDelta,...). The current proposal for the notification mechanism offers the same concepts:

The main difference lies in the fact that only active plugins are being notified, and plugins do not need to register to modifications. The newly added method registryChanged(IPluginRegistryChangedEvent) is always called.

Notification mechanism discussions