[Bug gcov-profile/49484] gcov crash if two(or more) forks happen at the same time

["redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49484

--- Comment #21 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-03-12 15:54:46 UTC ---
(In reply to comment #19)
> (In reply to comment #18)
> > Also, gthr.h says the signature should be:
> >   void __GTHREAD_MUTEX_INIT_FUNCTION (__gthread_mutex_t *)
> 
> I don't understand this?
> 
> The current define is pre-existing
> 
> #ifdef _GTHREAD_USE_MUTEX_INIT_FUNC
> # undef __GTHREAD_MUTEX_INIT
> # define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function
> #endif
> 
> I suppose it simply forgets to undef __GTHREAD_MUTEX_INIT_FUNCTION like
> the _GTHREAD_USE_RECURSIVE_MUTEX_INIT_FUNC does.

No, that was intentional.

Before your commit gthr-posix.h never defined __GTHREAD_MUTEX_INIT_FUNCTION
(because all POSIX targets define PTHREAD_MUTEX_INITIALIZER) so there was no
need to undef it.  However, gthr-posix.h sometimes defines
__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION (because not all POSIX targets provide
PTHREAD_RECURSIVE_MUTEX_INITIALIZER) so I needed to undef it before
(re-)defining it.  I could have alternatively done:

#ifndef __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION
#define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION ...
#endif

But I chose to just #undef it then #define it.


> I have no access to the weird platforms (but asked for help three month ago
> and again a week ago).

Yes, sorry, I don't subscribe to gcc-patches so only saw it when the change was
committed.

> Please open new bugs for issues you spot.

OK, will do.

> Btw, the gthr-posix.h path with _GTHREAD_USE_MUTEX_INIT_FUNC could have
> never worked as there was no __gthread_mutex_init_function available
> in gthr-posix.h.  Or how was that supposed to work?

I added __gthread_mutex_init_function, that's why it's there twice now.  Your
patch added another copy of it right below mine!

But my change was only made a month ago:
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183955
So when you first prepared your patch it was correct. Now it's not.