Describes asynchronous services provided by same thread code.
Sometimes, services are presented as asynchronous even when they are provided by code in the same thread as its client.
Symbian platform’s asynchronous services are so easy to use that it’s often convenient to code some long-running background operations as an asynchronous service, which in other operating systems would be coded using a separate thread.
It can also be convenient to define a high level class that can pass on requests to an asynchronous service provider in the Kernel. The class presents an asynchronous interface to its clients, but is intended to run in the same thread.