Do I need to synchronize my stubs?

Question

I have a client application that gets an RMI stub for an object in my server application. I am adding a shutdown hook to the client application, and I want to use the RMI stub in the shutdown thread. I'm concerned that my main thread may be in the middle of calling myStub.method1() when my shutdown hook code will want to come along and call myStub.method2(). Even if I make method1() and method2() synchronized, is concurrent use of a stub object safe? Or would I also want to synchronize the two calls in my client code?
Thanks,
M

Answer 1

Yeah, I was concerned about that too. The Javadoc for the shutdown hook stuff is full of scary warnings. I haven't really started testing what I wanted to do in my shutdown thread. This question was just looking ahead a bit. I had a bad feeling once I saw the Javadoc that a small redesign was going to be in order, but that's a bit off-topic.
So I shouldn't be doing network stuff in a shutdown hook, which makes my initial query a bit of a moot point. But what about the more general case, where I have two or more threads (none of them is part of a shutdown process) that want to share a single RMI stub object on the client? Is that safe to do, or does access to the stub need to be synchronized, even if the server's methods are marked as synchronized too? I just found an old thread (shown in reference [1] below) that I interpreted as saying that you SHOULD synchronize on the client, since the RMI spec doesn't specify that RMI stubs are thread safe. Am I reading that conversation right? That thread is 7 years old, so I'm not sure if it still applies.
--M
[1] - http://forums.sun.com/thread.jspa?threadID=167326&messageID=509076