(Having been told of a solution to one problem (File::CREAT was indeed what was needed), I'll now go off on something entirely different.) I've been trying to figure out how thread safety works, and mostly failing. I can sort of understand how the examples work, but I don't quite see how to take it and implement something useful. Basically, I'm going to have some objects. Only one thread should access an object at a time, and each thread will only access one object at a time. I'd like to be able to put something in the object that a thread can call on, which will allow the thread to continue when the object is available, and then the thread can release the object so other threads can use it. This doesn't seem quite appropriate to use a mutex, and ConditionVariable, which sounds like it's doing something similar, is always used within a mutex. Also, a thread shouldn't wait until a something else sends a signal - unless some other thread has specifically asked for the object, it should execute immediately. The Semaphore library on RAA sounds like it might do something like this, but I haven't been able to figure out quite how it works, so I'm not certain if it does what I want. Can anyone explain to me how to do something like this? -Morgan __________________________________ Do you Yahoo!? Exclusive Video Premiere - Britney Spears http://launch.yahoo.com/promos/britneyspears/