Multi-threading in Custom Adapter

Ok, all you Java gurus, here is a question for you:

We have a custom adapter that we’ve implemented to access information from a 3rd party vendor. Because of the significant volume of tansactions that this adapter needs to handle, we need to configure it for multi-threading (Document Order: Unordered; Number of threads=10).

Because we’re enabling multi-threading, do we need to synchronize any of the code inside our custom routines accessing the 3rd system?!

Please help us understand it.