Send a arraylist of objects through rpc

Hi

If I want to send an arraylist of objects through rpc, what will be the best way to do it? I would like to put the rpc call in a loop, but how can I make the rpc call synchronized each other?

That means send the rpc request one after one, and I dont want to build a messy rpc nest.

Or, I can create a rpc call which accept the arraylist as input.

Which way is better?

Thanks