Re: A clean way to detect if a ldap_pvt_thread_mutex is locked (best would be also to know who's the owner of the lock :)

[Hallvard B Furuseth <h.b.furuseth@usit.uio.no>]

Pierangelo Masarati writes:
> I fear yet more few minor concurrency issues in libldap; I'd like to
> be able to assert if a mutex is locked from inside library functions,
> and it would be great to also know who's locking it.  What I'd do is
>
> #define ISLOCKED(m) \
>         ( ldap_pvt_mutex_trylock( (m) ) ? 1 \
>                 : ( ldap_pvt_mutex_unlock( (m) ), 0 ) )

Huh?  That returns true if _some_ thread holds the lock and false
otherwise - except that the return value may be obsolete by the time it
is used.  And I don't know if all thread packages behave well if a
thread attempts to lock a mutex it already owns.

If you want a way to ask a mutex if it is locked by the current thread,
I suppose there are some thread implementations which support that, but
I don't see it in pthreads.

-- 
Hallvard