On Oct 20, 1:50 pm, Lie <[EMAIL PROTECTED]> wrote: > On Oct 19, 4:01 am, sokol <[EMAIL PROTECTED]> wrote: > > > > I started googling for scheduler and found one in standard library > > > > but ih has the same code as mine (it calls the functions in the > > > > right order and my doesn't, but it still waits too long). > > > > The other schedulers from web are dealing with > > > > repeating tasks and such. > > > > I believe you're looking for the 'sched' > > > module:http://www.python.org/doc/2.5.2/lib/module-sched.html > > > The sched module behaves just like mine version because > > it uses almost the same code. My observations include the > > sched module as well. Check it's source code. It is flawed: > > it calls the sleep method and while it sleeps (presumably > > for a long time) all newly scheduled events are on hold. > > See my example in original post. > > > My code solves this problem (or so it looks to me right now). > > Alternatively, if you're only handling Timers, you could use an event > loop that would check a list of timers and check their expiry time, > and execute the appropriate callback when the timer expired.
And that is what I'm doing. The trick is to do it correctly while: 1. Not using the processor time in useless loops and checks -> use sleep() 2. Sleep just as much as it is needed and not too much -> wake from sleep if there are new tasks since new tasks could be scheduled for some earlier point in time. My solution was: introduce "new_task" event and sleep on it with desired timeout. If new tasks arrive I will be awaken before the timeout and get a chance to reexamine if I need to sleep less than before. Scott's solution was: keep the queue empty so you get awaken automatically when new tasks are queued. Much simpler. Also, threading is quite necessary in my case: this "event loop" is not the main loop of the program as is found in GUI applications, but rather a plain old scheduler which runs some tasks concurrently to the main thread of execution. What was a surprise to me was that python sched.py makes the same mistake as I did in my first version. Tvrtko -- http://mail.python.org/mailman/listinfo/python-list
