Re: [Boost-users] *****SPAM***** Re: shared_ptr singleton

Subject: Re: [Boost-users] *****SPAM***** Re: shared_ptr singleton
From: Frank Mori Hess (fmhess_at_[hidden])
Date: 2008-10-16 22:56:09

On Thursday 16 October 2008 18:42, Peter Dimov wrote:
>
> The problem is that the default constructor may be invoked after the
> first call to Register::global, overwriting _global and resetting it to
> empty. The first subsequent call to global() would now reinitialize it.
>
> You can avoid this by making _global a local static:
>
> static RegisterP global()
> {
>     static RegisterP _global( new Register );
>     return _global;
> }

Hmm, so I guess it is impossible to make a thread-safe singleton that 
avoids the static initialization order fiasco, unless your compiler 
guarantees thread-safe initialization of local statics.  Even 
boost::call_once would require the once_flag to be statically initialized 
before the call_once call happens.