Ok, I'm no expert here but I've been experimenting with Indy for a few
years so here's my shot:
> I am writting a service application that recieves messages, processes
> them, and sends a response.
Cool, sounds similar to something I've been working on.. (Instant messenger
though I use TCPserver/Client..)
> I am using a TidUDPServer to handle the incoming messages. Then I start a
> thread to actually process the message. Each thread will then send a
> response back to the originator of the message.
I never did that. I'm not sure but I thought ALL indy servers were
multithreaded anyway?
Not sure but if your UDPserver is multithreaded like the TCPserver, then you
don't need to fire a seperate thread as it will automatically create a new
thread instance and execute the code you've written in the unit. Though
beware, this has been my achilles heel in the past: My tcp thread could not
send commands to a component on the form - I had to put the text into a
public string and set a timer to read it..
Now I ain't sure about UDPserver but assuming its the same as the TCP you
just need to write your handling code (IE, process the message, do database
lookup [ini files are surprisingly good too] etc and send response) and the
UDPserver will automatically thread it with a new instance based on your
unit at runtime.
> My question is will I have a problem when trying to send messages in my
> threads? I can end up in the situtuation that more than one will try to
> respond at the same time. I was thinking that each thread would create an
> instance of TidUDPServer to Send the data. Am I going to run into trouble
> because sooner or later two or more TidUDPServer components will be
> reading/writing to the same port? Should I route all my transmissions
> through a since thread so as to avoid any concurrency problems?
If Indys UDP server is the same as TCP - Multithreaded you can simply write
your code in the same unit as the UDP event handlers and then compile and
run. The UDPServer will keep track of all the threads etc automatically
(Though you might need a threadpool component - in the Indy [servers I
think] tab on the pallette) and handle them automatically. Indy really is
the way to go in that respect as it makes threaded servers so much easier to
handle.
Hope this helps
