C# 4 and .NET 4

Creating a Windows service Program ❘ 677
class is created and passed as the first element to the ServicesToRun array. If more than one service should
run inside this service process, it is necessary to add more instances of the specific service classes to the
array. This array is then passed to the static Run() method of the ServiceBase class. With the Run()
method of ServiceBase, you are giving the SCM references to the entry points of your services. The main
thread of your service process is now blocked and waits for the service to terminate.
Here is the automatically generated code:
///
/// The main entry point for the application.
///
static void Main()
{
ServiceBase[] ServicesToRun;
ServicesToRun = new ServiceBase[]
{
new QuoteService()
};
ServiceBase.Run(ServicesToRun);
}
code snippet QuoteService/Program.cs
If there is only a single service in the process, the array can be removed; the Run() method accepts a single
object derived from the class ServiceBase, so the Main() method can be reduced to this:
ServiceBase.Run(new QuoteService());
The service program Services.exe includes multiple services. If you have a similar service, where more
than one service is running in a single process in which you must initialize some shared state for multiple
services, the shared initialization must be done before the Run() method. With the Run() method, the main
thread is blocked until the service process is stopped, and any following instructions would not be reached
before the end of the service.
The initialization shouldn’t take longer than 30 seconds. If the initialization code were to take longer than
this, the SCM would assume that the service startup failed. You need to take into account the slowest
machines where this service should run within the 30-second limit. If the initialization takes longer, you
could start the initialization in a different thread so that the main thread calls Run() in time. An event
object can then be used to signal that the thread has completed its work.
service start
At service start, the OnStart() method is called. In this method, you can start the previously created socket
server. You must reference the QuoteServer assembly for the use of the QuoteService. The thread calling
OnStart() cannot be blocked; this method must return to the caller, which is the ServiceMainCallback()
method of the ServiceBase class. The ServiceBase class registers the handler and informs the SCM that
the service started successfully after calling OnStart():
protected override void OnStart(string[] args)
{
quoteServer = new QuoteServer(
Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "quotes.txt"),
5678);
quoteServer.Start();
}
code snippet QuoteService/QuoteService.cs
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