Re: Mutex error on recent Redhat systems

[Kay-Uwe Kasemir <kasemirk@ornl.gov>]

> The error message is from src/libCom/osi/os/posix/osdThread.c at  
> the top
> of the routine epicsThreadOnceOsd(), and occurs if mutexLock 
> (&onceLock)
> returns a non-zero status.  The mutexLock() routine is one of ours  
> that
> calls pthread_mutex_lock() and handles retrying in the event that it
> returns EINTR (which violates the SUSv3).

Hi:

Just a vague guess because DDJ just happens to run an article this month
on static initialization of mutexes, pthread_once etc.
(
Developing Lightweight, Statically Initializable C++ Mutexes;
Threadsafe initialization of Singletons
Vladimir Kliatchko
DDJ May 2007
):

Looks like the onceLock used by epicsThreadOnceOsd() needs to be
initialized by a proper call to epicsThreadInit(), which calls
once(), which performs pthread_mutex_init(&onceLock,0).
Then it's destroyed later from an atExit routine.
Maybe that doesn't happen at the correct time, so the bad status
is the result of a destroyed mutex?

Maybe one could simply use static initialization of the onceLock, i.e.:

static pthread_mutex_t onceLock = PTHREAD_MUTEX_INITIALIZER;

?

That way, there's no need to specifically create nor destroy it.

-Kay

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