Unlocking a robust mutex in a cleanup handler
dimitri.staessens at intec.ugent.be
Tue Dec 6 10:59:25 UTC 2016
first of all, thank you for supporting robust mutexes in FreeBSD 11.
I'm having some issues with a thread that holds a robust mutex (residing
in a POSIX shared memory (shm) segment) in conjunctions with a condition
variable (also in that POSIX shm) on which that thread is blocked via a
pthread_cond_wait() call. pthread_cond_wait tries to retake the mutex
after the thread cancellation signal is received, and there is a
pthread_mutex_unlock pushed to the cleanup stack to unlock that robust
mutex in case of a cancellation.
Cancelling that thread works fine on Linux, however, on FreeBSD
11.0-RELEASE, if I pthread_cancel that thread I can't get past the
following check and resulting PANIC call:
After removing the check and recompiling libthr everything seems to work
Could this be a bug in libthr or am I missing a nuance in the use of a
shared robust mutexes in conjunction with condition variables?
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