John D Giotta schrieb: > I'm looking to run a process with a limit of 3 instances, but each > execution is over a crontab interval. I've been investigating the > threading module and using daemons to limit active thread objects, but > I'm not very successful at grasping the documentation. > > Is it possible to do what I'm trying to do and if so anyone know of a > useful example to get started?
Since you are talking about crontab I assume that you are on an os that supports pthreads. You problem can easily be solved with a named semaphore (see sem_open(3) and sem_overview(7)). Unfortunately Python doesn't expose named semaphores. The multiprocessing library uses named semaphores but you can't set the name yourself. You have to write your own C wrapper or search on pypi and through Google. If you are going to write your own semaphore I highly recommend Cython. Christian -- http://mail.python.org/mailman/listinfo/python-list