Thanks João.

We are working on a medical prototype, and I wouldn't want to rely on our own version of something so fundamental without having a thorough test harness for it, which would obviously be quite time-consuming, and something of a dead-end.

I've worked around the issue now (the system pushing to a queue has to be given a Condition to set when they push, so that if a system listens on multiple queues it can give all the senders the same Condition), but it makes the architecture quite messy, just being able to wait on one of several Conditions would have been neater and less error-prone.

I suppose I expected to see this method because I'm familiar with the Windows API. But I checked and it is not present in the posix threading API, so there is some justification for peoples' reluctance to implement it in Python.

Thanks again,

Richard