Hello Abraham, Thursday, April 21, 2005, 6:47:27 PM, you wrote: AE> Suppose that a program using the Control.Concurrent.STM module had a AE> producer/consumer setup - one thread writing to a channel, the other AE> thread reading from the channel. It seems natural to want a function AE> that the producer can call that will block until the consumer has AE> finished consuming everything currently in the channel. i think this is a bad programming technique. it's better to use another discipline of managing queue. for example, in my program i just allocate fixed number of buffers and use them to send data over channel. as a result, channel can't contaion more than this nu,ber of elements. if you will say more about your GOAL, not particular decision you made, may be i can suppose you better solution -- Best regards, Bulat mailto:bulatz@HotPOP.com