There is a main class starting threads for Producers and Consumers in this manner (Producers push onto a stack, consumers pop):

Consumer.start()
Producer.start()
Consumer.start()
Producer.start()


I need to make sure that the 2 producers enter first, then the 2 consumers.


Right now I have a semaphore.wait() (set to 0 initially so it won't run) in the Consumer class. Right now I'm using semaphore.signal() at the end of the Producer class, but that isn't right (I need the 2 Producers to run first).

Where can I put my semaphore.signal() ? (I can't change my main, so I can't put it after my second Producer.start() )


/e It seems as if my code is running correctly, but I'm pretty sure it's just a coincidence xD

This post was edited by IsraeliSoldier on Feb 24 2013 09:28am

Kind of hard to understand your question, but if you need both Producers to run before either of the Consumers run, you could initialize the semaphore to -1, then have each Consumer wait on the semaphore while each Producer runs and then signals the semaphore when done.

Ex:

Semaphore S = -1

Consumer


Producer


This post was edited by Schwag on Feb 24 2013 04:18pm

Oops, I meant initialize it to 1, not -1; can't edit again though.

I got it to work, I actually needed 3 Semaphores ><. There were 4 threads created, so:

1 semaphore to make sure only 1 Producer is allowed in at a time to keep mutual exclusion
1 semaphore used as a mutex for Producer and Consumer
1 semaphore used to signal the Consumer when all producers are done

Thanks for the help

This post was edited by IsraeliSoldier on Feb 26 2013 09:57pm