NetBSD-Users archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: POSIX semaphore/shared memory management/monitoring tools (Eric Schnoebelen) writes:

>Sorry, kre,  but I haven't been able to get ipcs(1) to provide
>information about POSIX named semaphores.

SYSV semaphores and POSIX semaphores are completely independent.

POSIX semaphores are implemented as file objects in a private kernel
list, see _ksem(2). There is no way to enumate them. You can check
how many exist with:

% sysctl kern.posix
kern.posix.semmax = 128
kern.posix.semcnt = 0

Unnamed semaphores are deleted automatically when closed by all processes,
but named semaphores persist until deleted by a call to sem_unlink().

                                Michael van Elst
                                "A potential Snark may lurk in every tree."

Home | Main Index | Thread Index | Old Index