Re: address@hidden: Re: emacs-22.1 with GTK dumps core when Gnome wigets clicked]

[Jan Djärv]

YAMAMOTO Mitsuharu skrev:
> > > > > > On Sun, 17 Jun 2007 17:49:28 -0400, Richard Stallman <address@hidden> said:
>
> > Would someone else (other that Mitsuharu) please study this patch to
> > check whether it is really correct?  Things like this can be tricky.
>
> Please take a look at the following one instead.  It tries to fix the
> following problems of gmalloc.c with HAVE_GTK_AND_PTHREAD in Emacs 22.1.
>
> * HAVE_GTK_AND_PTHREAD was checked before including config.h.
> * malloc_initialize_1 called pthread_mutexattr_init that may call malloc.
> * _aligned_blocks was not protected.
> * __malloc_hook etc. may be modified between its NULL-check and the use.

The patch was corrupted by some mailer so I could not apply it, but:

!   /* Copy the value of __malloc_hook to an automatic variable in case
!      __malloc_hook is modified in another thread between its
!      NULL-check and the use.  */
!   hook = __malloc_hook;
!   return (hook != NULL ? *hook : _malloc_internal) (size);
  }

Assignment is not guaranteed to be atomic.  It probably is on 32-bit systems, 
but you should not assume it.

        Jan D.