Subj : Re: Can C++ local static objects be made thread safe?
To   : comp.programming.threads
From : Marcin 'Qrczak' Kowalczyk
Date : Wed Feb 16 2005 04:49 pm

gniccolai@yahoo.com (Giancarlo Niccolai) writes:

>> It may not reenter the_safe_initializer. Reentering a static local
>> initializer before its previous run has finished is forbidden by the
>> C++ standard.
>
> There is no reason why I may not lock a mutex before entering a
> function (constructor or anything) that uses it as well (provided it
> is reentrant).

You may lock the reentrant mutex again, but you may not enter the
static local initializer again. Since a deadlock caused by a mutex
around static initializer could happen only if you enter the local
initializer again, it never happens in code which isn't already
broken.

> The above pattern usage is correct, under any standard, and an
> automated mutex locking done under the nose of the developer would
> break it.

It does not break it.

Please show me the real code, not pseudocode. The compiler doesn't
insert locking around calling functions; it inserts them around
dynamic initialization of static locals. I don't see a static local
in your code.

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

.