Is there any special way to a trigger send a signal to outer application?

Hi!

Windows Server, PGSQL.

When a new records arrived to the database, I want process them in the
background.
I have a processor service.
This is periodically (5-10 minutes) checking the "message" table, and if
there is some message, it is process them.

This periodic processing is good, but I want to decrease the process
time, when records arrived (to increase the performance, and dec. the
user's waiting).

So I search for a way to do any IPC communication from PGSQL to the
processor service.

Which way is supports by PGSQL trigger?

a.) Starting a new process with any params (this app. can send a WM_*
message to my service)?
b.) Sending a WM_* message (PostMessage) to my service?
c.) Sending a TCP message to my service?

Or other?

If you have an example about this problem, please send me with the answer!

Thanks for your help:
dd