Subj : Re: Can C++ local static objects be made thread safe?
To   : comp.programming.threads
From : David Schwartz
Date : Wed Feb 09 2005 09:22 am


"Marcin 'Qrczak' Kowalczyk" <qrczak@knm.org.pl> wrote in message 
news:87vf922dst.fsf@qrnik.zagroda...

> If it caused a deadlock, the program would have to enter initialization
> of a particular local static variable before the previous initialization
> of that variable finished. But with the traditional non-thread-aware
> implementation of local static initializers this has undefined behavior.
> So it doesn't break anything which wasn't already broken.

    This analysis is not correct, it relies upon two different concepts of 
when initialization is finished.

    Remember, you need to wrap the entire initialization function in a lock 
of some sort, not just the process of determinine whether the initialization 
has taken place or not. It is perfectly legal for code inside the 
constructor to dispatch another thread and for that other thread to call 
functions which invoke static initializers.

    DS

.