In this series of articles I have been demonstrating a simple approach to making Windows services. In the previous article I discussed the different components generally involved in writing a service. I also provided the code for the service host and started working on the service instance. In this article I’m going to finish up the implementation of the service and demonstrate how all this comes together.

In the last article I provided an overview of Windows services and the issues involved in writing one compared to a normal program. In this article I will demonstrate how to write a simple service in a way that helps alleviate these issues. Before getting into the code for a service it is important to reiterate that a single process can host multiple services at the same time and each service can be started or stopped on its own. It is therefore useful to break up a service into its components so that each component does only what it is expected to do. When creating a service I find that there are 3 different components: service host, service instance(s), and service worker.

In Windows a service is a process whose lifetime is managed by the system rather than by a user. MSDN describes a service as a long running process and often times this is true. Services tend to start before a user logs in (or shortly thereafter) and run until the system shuts down. This is unlike traditional applications that start up after a user logs in and terminates when they log out. While a service looks a lot like a standard application they behave quite a bit differently. In this article I’ll discuss some of the issues around creating a service and ways to make it easier to write and debug one.