Re: [Boost-users] Trouble with asio using lib pion and boost.function

Subject: Re: [Boost-users] Trouble with asio using lib pion and boost.function
From: Stephan Menzel (stephan.menzel_at_[hidden])
Date: 2008-11-26 17:06:00

Hi Steven,

> >     return static_cast<vtable_type*>(vtable)->invoker
> >              (this->functor BOOST_FUNCTION_COMMA BOOST_FUNCTION_ARGS);
> >   }
> > #endif
> >
> > It says the static_cast rises the exception (?!) Damn MS.
>
> a) Is the error on the static_cast or on reading the function pointer?

Alas, I can't really tell. For the compiler this is one line. But I have to 
assume it's coming out of the functor. At least this is what the debug run 
looked like.

> b) does it happen consistently?

Yes, every time.

> This could be the 1.36 Boost.Function thread safety regression.
> There is a race condition that can prevent invoker from being
> properly initialized before it is used.

Bad news indeed. But it would have to be something rather platform dependent 
such as this. Despite all efforts I couldn't reproduce it on either 64bit or 
32bit GNU/Linux boxes I tried.
Alas, it still get's worse. Trying to figure out if an update to 1.37 would be 
in place I ran into this: 
http://groups.google.tl/group/boost-list/browse_thread/thread/c19823879d3cdecc
Apparently boost.asio fails to work in 1.37 on windows. Which is mighty 
disappointing, since I hold asio in such high esteem.  So is there any other 
way of fixing that so I could see if that was it? A patch for 1.36 perhaps?

Apart from this, wouldn't a race condition bound to be a little more hard to 
catch? Usually the buggers tend to be rather unreproducable to the point you 
doubt they exist.

Cazart,
Stephan