Debugging Tips

• Make sure you really understand the actor model, its message passing semantics, and the concurrency coordination abstractions built in SALSA.

• Message passing and remote procedure calls are totally different. A named token variable does not have the result immediately. It has the result only after the message gets executed.

• Objects in messages have pass-by-value semantics. This means that object arguments are cloned and then sent. A latter modification on these object arguments does not change the objects which were originally sent.

• Since the SALSA compiler does not support type checking in this version, you may need to go through the Java source code. The code related to your program is on the bottom of the generated Java source code. Do not try to modify other parts irrelevant to your SALSA source code.

• Please note that a typo in a message sending statement does not generate Java or SALSA compile-time errors. You have to be very careful with that. A run-time error will be generated instead.

• Most people confuse self with this. this means "this actor", while self "the actor reference" pointing to itself. self can only be used as a target of messages, or an argument to be passed around. this can be used for object method invocation. To send your references to other actors, use self. Using this is wrong.