According to QNX RTP 6.1.0 docs mutexes implement the basic priority
PHTREAD_PRIO_INHERIT. I’ve tried to set the Immediate ceiling priority
protocol PHTREAD_PRIO_PROTECT. According to docs this is still not
implemented. However pthread_mutexattr_setprotocol does not complain.
Should I conclude that it works?
Then, how should the ceiling of a mutex be setup?