On Apr 29, 3:01 pm, Dennis Lee Bieber <[EMAIL PROTECTED]> wrote: > On Sun, 27 Apr 2008 03:27:59 -0700 (PDT), Terry <[EMAIL PROTECTED]> > declaimed the following in comp.lang.python: > > > I'm trying to implement a message queue among threads using Queue. The > > message queue has two operations: > > PutMsg(id, msg) # this is simple, just combine the id and msg as one > > and put it into the Queue. > > WaitMsg(ids, msg) # this is the hard part > > > WaitMsg will get only msg with certain ids, but this is not possible > > in Queue object, because Queue provides no method to peek into the > > message queue and fetch only matched item. > > > Now I'm using an ugly solution, fetch all the messages and put the not > > used ones back to the queue. But I want a better performance. Is there > > any alternative out there? > > Create your own queue class -- including locking objects. > > Implement the queue itself (I've not looked at how Queue.Queue is > really done) as a priority queue (that is, a simple list ordered by your > ID -- new items are inserted after all existing items with the same or > lower ID number). > > Surround list manipulations with a lock based on a Condition. > > Now, the trick -- the .get(ID) sequence being something like (this > is pseudo-code): > > while True: > self.condition.acquire() > scan self.qlist for first entry with ID > if found: > remove entry from self.qlist > self.condition.release() > return entry > self.condition.wait() > > -=-=-=-=- the .put(ID, data) looks like > > self.condition.acquire() > scan self.qlist for position to insert (ID, data) > self.condition.notifyAll() > self.condition.release() > > -=-=-=-=- > > Essentially, if the first pass over the list does not find an entry > to return, it waits for a notify to occur... and notification will only > occur when some other thread puts new data into the list. > -- > Wulfraed Dennis Lee Bieber KD6MOG > [EMAIL PROTECTED] [EMAIL PROTECTED] > HTTP://wlfraed.home.netcom.com/ > (Bestiaria Support Staff: [EMAIL PROTECTED]) > HTTP://www.bestiaria.com/
Yes, now I have a similar solution in my code. But after read the stackless python, I'm thinking if I can move to stackless, which might improve the performance of my thread. Because I'm trying to simulate some behavior of the real world (trading), I believe there will be a lot of threads in the future in my program. -- http://mail.python.org/mailman/listinfo/python-list
