Re: [boost] [singleton] call_once

From: Jason Hise (chaos_at_[hidden])
Date: 2005-09-13 10:39:04

John Maddock wrote:

>The mutex is unique to both the calling process and the call_once flag, but 
>not the function pointer (however there should always be a one to one 
>correspondence between the once-flag and the function pointer).
>
I should probably elaborate on my problem a little bit more.  I wanted 
to create a function that makes a given call atomic, but doesn't enforce 
that the function be called only once.  I thought I could do so by using 
a once_flag allocated on the stack immediately before invoking 
call_once, so the flag would always be reinitialized to BOOST_ONCE_INIT 
and call_once could just offer me it's atomic guarantees, but apparently 
that won't work.  I guess I'll just have to find some place to put my 
own mutex where it can be constructed safely.

-Jason