Batch Processing design pattern?

I am on this project that will necessarily have to do a batch
processing of some transactions.

Are there any design patterns that you are aware of regarding batch
process implementations in an object oriented fashion. The features
required are:

=> Parallel processing of mutually exclusive calculations
=> A multi-step process wherein after all the parallel calculations in
step1 are done then run all parallel calculations in step2.

I can work on implementing this but if there is already one out there,
might just as well reuse it.

Yes. there are multiple design patterns that you can use to accomplish
this task. What you need to look for, are design for demultiplexing
events and concurrent events processing. You'll need a reactor, the
leader/followers and the asynchonous completion token as a very first
base of your application.

In order to understand those patterns correctly, you should read POSA2.
"Pattern Oriented Software Architecture" volume 2.

If you never used patterns before, I recommand you to begin with the
first volume. This is not a good book to introduce someone to design
patterns, but it is a very good book for anyone that have experience
and want to develop a server application or anything that do batch
processing.

iscy