C# Advice about queueing

I am seeking advice on a project I have been assigned and I'm looking to see how it's done "professionally," or any suggestions that can lead me to the right direction.

I have a server piece that accepts commands from clients and pushes out byte streams to a serial port. Although multiple clients can send commands to this server piece, our hardware only can handle one command at a time. My problem is with queueing in the software end.

I've implemented a Queue<T> helper class that also inserts data into a DataSet containing: the requesting client number, message data (byte array to write to serial port) and message type (command description). It will also list the queue commands in a DataGrid (on the Form). Probably not the way to go, but that's the only thing I can think of as far as retaining the requesting client and the data and showing, visually, the queue.

Where do I han开发者_C百科dle the processing of the queue? I thought about handling it on a custom event where if the DataGrid list changed (item added/removed), grab the first row of data in the DataSet and send it out to the serial port.

Any comments or suggestions are greatly appreciated.

Thanks.

Edit: I forgot to add that it does require a response from the SerialPort as well, in order for the current executed command to be removed from the queue.

I would use a database table to store the queue of commands. The web app would add records to the queue and display the queue, then a separate process (such as a Windows service or console app) would request the next command from the database and send it to the serial port.

Client requests can come in at any time, they'll probably be handled by some proxy class (WCF?) on its own thread/task. Then that thread/ task needs to coordinate with the task that's 'inside' the model actually processing the requests.

A good class to do this with is the BlockingCollection.

The server-thread will block until there's something in the collection to work on. It can then take it from the collection in a thread safe manner and process it. Doing it this way ensures that the requests can be accepted when they arrive, but they are processed on at a time.

The overall pattern to think of here is producer-consumer.

GJ

If it is a high trasaction web application you might want to look at queueing system such as MSMQ, Service Broker Queue or RabbitMQ. Window service can then pick up the queued items and send it to serial port.