Subj : Re: Can C++ local static objects be made thread safe?
To   : comp.programming.threads
From : Bruce Visscher
Date : Fri Feb 11 2005 02:02 pm

>    It *might*. But don't you want to write code that guaranteed to
> work because it complies with the relevant standards

Absolutely.

> rather than code that just
> happens to work because you fixed all the problems that were biting
> you but left the ones that didn't happen to bite you that day, on
> that compiler, on that platfor, with that data set?

No, I want to avoid that.

>     I think the '__thread' keyword was meant to mark a thread-local
> variable. If you don't have it, you need to use whatever thread-local
> variable support you do have.

I'll have to ponder how to do this using the pthread interface.

>    Sounds like you're trying to code to a particular platform.

Actually, I am trying to avoid that.

> You'll need
> to find someone with specialized knowledge about that platform,

I think I might be able to write:

#ifdef __VMS
Item &cofu() {
   static Item the_item;
   return the_item;
}
#elif HAVE_THREAD_KEYWORD
// use the __thread keyword as suggested in this (ng) thread.
#else
// I want to know what goes here.
#endif

Before "resorting" to pthread_key_create / pthread_getspecific /
pthread_setspecific / pthread_key_delete I could also maybe try to use
atomic exchange for those platforms that have that.  But this is
starting to look a little cumbersome.

> and your code will not be portable.

That's what I am trying to avoid.

Thank you for your patience.

.