Subj : Re: Can C++ local static objects be made thread safe?
To   : comp.programming.threads
From : Marcin 'Qrczak' Kowalczyk
Date : Wed Jan 19 2005 12:48 am

Olivier Huet <huet-pasdespamsvp-.o@caramail.com> writes:

> Here are some arguments for "not" locking : C++ itself doesn't include
> any multithreading features, so why should the compiler include a lock
> here ?

IMHO if the compiler supports threads, it should act as if it
implemented a hypothetical extended C++ standard with threads.
A reasonable semantics of static variables in functions in
multithreaded C++ would require locking.

> And if it does, what kind of lock : process wide (for multiple
> threads that access the variable), system wide (for multiple process
> that access the variable), etc etc. ?

Depending on whether the variable is process wide or system wide.

Generally I tend to associate implicit locks with global objects
(singletons) and explicit locks with local, "anonymous" objects.

-- 
   __("<         Marcin Kowalczyk
   \__/       qrczak@knm.org.pl
    ^^     http://qrnik.knm.org.pl/~qrczak/

.