Windows Service and multithreading

Im working on a Windows Service in which I w开发者_运维问答ould like to have two threads. One thread should look for updates (in a RSS feed) and insert rows into a DB when updates is found.

When updates are found I would like to send notification via another thread, that accesses the DB, gets the messages and the recipients and then sends notifications.

Perhaps the best practice isn't to use two threads. Should I have db-connections in both threads?

Could anyone provide me with tips how to solve this?

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The major reason to make an application or service multithreaded is to perform database or other background operations without blocking (i.e. hanging) a presentation element like a Windows form. If your service depends on very rapid polling or expects db inserts to take a very long time, it might make sense to use two threads. But I can't imagine that either would be the case in your scenario.

If you do decide to make your service multithreaded, the two major classes in C# that you want to look into are BackgroundWorker and ThreadPool. If you want to do multiple concurrent db inserts (for example, if you want to execute an insert for each of multiple RSS feeds polled at the same time), you should use a ThreadPool. Otherwise, use a BackgroundWorker.

Typically, you'd have a db access class that would have a method to insert a row. That method would create a background worker, add DoWork handler to some static method in that db access class to the background worker, then call DoWorkAsync. You should only have db connection settings in that one class in order to make maintaining the code easier. For example:

public static class DbAccess
{
    public void InsertRow(SomeObject entity)
    {
        BackgroundWorker bg = new BackgroundWorker();
        bg.DoWork += InsertRow_DoWork;
        bg.RunWorkerCompleted += InsertRow_RunWorkerCompleted;
        bg.RunWorkerAsync(entity);
    }

    private void InsertRow_DoWork(object sender, DoWorkEventArgs e)
    {
         BackgroundWorker bg = sender as BackgroundWorker;
         SomeObject entity = e.Argument as SomeObject;

         // insert db access here
    }

    private void InsertRow_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
         // send notifications
         // alternatively, pass the InsertRow method a 
         // delegate to a method in the calling class that will notify
    }
}