Hello Colleagues: Earlier I posted that I was having a problem involving the loss of deferred calls in a programme that uses Stackless and Twisted. I found the problem and wrote a solution. I think it interesting. It helped when I started using the Twisted logging facility :-) The immediate reason the deferred were "lost" was because the main reactor loop stopped iterating. What happened was: 1. In the example, Stackless treats Twisted as a tasklet. see: http://www.stackless.com/pipermail/stackless/2007-April/002448.html 2. When the Request Handler is created, it is running as a *part* of the Twisted tasklet. 3. Consequently when the Request Handler blocked on a channel, this blocked the entire reactor! In turn, doIteration() (doSelect) cannot do its work. Twisted grinds to a halt. 4. When the last tasklet (TestTasklet) blocked, all the tasklets became blocked. Consequently the programme ended. The solution was two-fold. 1) To prevent the reactor from blocking, I run the request handler in its own tasklet. This prevents the reactor from blocking for indeterminate periods of time. 2) I modified doSelect to call stackless.schedule(). If the reactor does not call stackless.schedule(), other tasklets will not get an opportunity to run. (When I have time, I will write a proper reactor. This should be a little more than overriding the doIteration() method of selectReactor). Or re-read the Blocking demo : I don't quite understand how it works) With this approach, I 1) Eliminate a OS-Thread (both Stackless and Twisted folks concur that this is wrong, wrong, wrong). 2) Can execute tasklets in parallel with tasklets that are blocked waiting for network I/O like an incoming HTTP request. I think it is neat that the Twisted framework is flexible enough to be contorted in this fashion. Unfortunately this approach is *very* slow. I feel it is wastefully that a tasklet is created for every incoming request. I have to work on this. ~ I understand the subset of Stackless and Twisted users is small. And the philosophies are different. And what I am doing is a bit esoteric and application specific. Hopefully others will be able to build upon this : I don't see why programmers can't get the best of the Stackless and Twisted worlds. Cheers, Andrew ____________________________________________________________________________________Yahoo! oneSearch: Finally, mobile search that gives answers, not web links. http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC