Thread: Eternal block of process with sem_wait ( )

Hello,

I'm working on a project upon Ubuntu Linux distribution, and I'm intended to use the semaphore interface provided by <semaphore.h>. The actual problem is, that when having two processes, let's say A and B, that lock their critical sections with the same semaphore, let's say s, B tries to lock semaphore (sem_wait) and goes into the CS, A tries to lock semaphore (sem_wait) but is blocked, and then B locks and unlocks (sem_post) the semaphore a lot of times, while A is sitting actionless... Even when B ends, A does not respond, as it seems to be blocked by its sem_wait. I would be grateful if anyone had any idea about this (except bad memory handling and wrong initialization, etc).

Thanx for any response!

Hm, the really weird thing here is that when B terminates, A still remains blocked, a fact that may rule out priority inversion.. :/

thnx anyway codeplug!

Are you sure you're working with the same semaphore (did you used an absolute path name if it's a named semaphore?). Could you post only the relevant sections of your code? (semaphore creation and usage), it's hard to tell otherwise.