I try to make benchmark for shared memory with semaphore, mutex and rwlock.
I init mutex with shared options in created shared segment, create one more shared segment with data, close it all, then
 fork, open it all in both processes and send/receive data (procnto with the -s option). After work with shared memory 
child process die, parent destroy mutex and shared mem.

And in this case i have a procnto fault(dump attached). App can work succesfully couple of times (count performance and 
show result) or not, but after that all times procnto crush (not in mutex using time defintely). 

But if i make a super parent app, which create segment, init mutex, close it, run 1st app (which make fork), waiting for
 end it and delete mutex - all works fine. So, shared mutex in my case works only with third process which control mutex
 life.

How it can works and how i can fix it? Im newbie in QNX and POSIX.
Fault dump and source in attachment.