Subj : Re: Can C++ local static objects be made thread safe?
To   : comp.programming.threads
From : Gianni Mariani
Date : Wed Feb 16 2005 09:00 pm

Alexander Terekhov wrote:
> Gianni Mariani wrote: 
> 
> [... struggling SGI ...]
> 
> Quoting SGI's docu:
> 
> ----
> For programs under the IRIX 5.3 and above, segments with the
> PF_MIPS_LOCAL flag set will be thread-local and not shared in 
> the event of an sproc(2) system call. 

IRIX 5.3 is 10 years old.

> 
> [...]
> 
> The sproc model of threading is incompatible with POSIX threads.
> Attempts to create an sproc process from a pthreaded program will 
> be rejected [see pthreads(5)].
> ----
> 
> Contrast it with {less struggling} Intel's* docu (C/C++ ABI):
> 
> ----
> Address-of operator
> 
> The address-of operator, &, can be applied to a thread-local 
> variable. This operator is evaluated at runtime, and returns 
> the address of the variable within the current thread. The 
> address obtained by this operator may be used freely by any 
> thread in the process as long as the thread that evaluated 
> the address remains in existence. When a thread terminates, 
> any pointers to thread-local variables in that thread become 
> invalid.
> ----
> 
> And, BTW, see also
> 

I don't know why you're so hung up about this issue.

What are the merits of making thread locals slow vs some arbitrary issue 
with POSIX threads conformance ?

It's not as if anyone here is representing the __thread extension is 
conforming in any way whatsoever.

I would prefer that speed of implementation is preferred over some 
unimportant rule here, that's the whole point, isn't it ?

.