Subj : Re: Can C++ local static objects be made thread safe?
To   : comp.programming.threads
From : David Schwartz
Date : Wed Feb 16 2005 02:28 am


"Alexander Terekhov" <terekhov@web.de> wrote in message 
news:42131205.B72DB5C2@web.de...

> David Schwartz wrote:
> [...]

>>     Thread-local objects are not supposed to be shared.
>
> Sez who?

    I am saying that. That is what makes them thread local.

>>                                                         As for it 
>> breaking
>> POSIX, POSIX doesn't say what the __thread specifier should do, so 
>> nothing
>> it could do would violate POSIX.
>
> Under C/POSIX different objects just can't have the same address.
> And threads share the entire address space. By definition.

    That's ridiculous. Providing no strictly-conforming code can tell the 
difference, POSIX is silent. And strictly conforming POSIX code can't use 
the '__thread' specifier.

    In any event, many implementations have at least one page that is not 
shared by all the threads. This is a common way to, for example, tell which 
thread you are.

    DS

.