threads/150889: PTHREAD_MUTEX_INITIALIZER + pthread_mutex_destroy () == EINVAL

[John Baldwin]

On Thursday, September 23, 2010 11:48:40 pm Jung-uk Kim wrote:
> On Thursday 23 September 2010 06:44 pm, Daniel Eischen wrote:
> > You shouldn't have to call pthread_mutex_init() on a mutex
> > initialized with PTHREAD_MUTEX_INITIALIZER.  Our implementation
> > should auto initialize the mutex when it is first used; if it
> > doesn't, I think that is a bug.
> 
> Ah, I see.  I verified that libthr does it correctly.  However, that's 
> a hack and it is far from real static allocation although it should 
> work pretty well in reality, IMHO.  More over, it will have a 
> side-effect, i.e., any destroyed mutex may be resurrected if it is 
> used again.  POSIX seems to say it should return EINVAL when it 
> happens. :-(

I think the fix there is that we should put a different value ((void *)1 for 
example) into "destroyed" mutex objects than 0 so that destroyed mutexes can 
be differentiated from statically initialized mutexes.  This would also allow 
us to properly return EBUSY, etc.

-- 
John Baldwin