Hi, Tommi Virtanen wrote:
counting the currently open IMAP connections and when the number is below the limit, taking more work from a queue
Or you could use a semaphore. Feel free to add this code to twisted.internet.deferred. The interface should be identical to python.threading.Semaphore, except that I was too lazy to add any verbose statements... class Semaphore(object): def __init__(self, value=1, verbose=None): self.queue=[] self.value=value def acquire(self): d=Deferred() if self.value: self.value -= 1 d.callback(False) else: self.queue.append(d) return d def release(self): if self.queue: self.queue.pop(0).callback(True) else: self.value += 1 The callback's parameter answers the "did I have to wait for a slot" question, in case the caller needs that question answered. (Most don't.) -- Matthias Urlichs | {M:U} IT Design @ m-u-it.de | smurf@smurf.noris.de Disclaimer: The quote was selected randomly. Really. | http://smurf.noris.de -- s = (char*)(long)retval; /* ouch */ -- Larry Wall in doio.c from the perl source code