Re: [boost] [thread] Use of _ReadWriteBarrier

From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2007-10-08 09:23:03

> > _ReadWriteBarrier stops the compiler from reordering. Going to a 
> > non-intrinsic InterlockedCompareExchange will also have 
> this effect, 
> > but it might be possible to achieve it in another (cheaper) 
> > compiler-specific way; __asm__ ( :::"memory" ) is the GCC 
> equivalent. 
> > Borland may already not reorder across a volatile read; 
> this needs to be tested.
> 
> Totally agreed. The easiest change to make mingw and Borland 
> non-broken was to use ICE, but it is definitely overkill if 
> there's a cheaper way.
> 
> All that's need here is a compiler barrier; I couldn't find 
> an equivalent in the Borland docs this morning, but that 
> doesn't mean there isn't one. Does __asm__ ( :::"memory" ) 
> work on mingw? If so, I'll use that rather than ICE for mingw.

FWIW, Intel V10 on Windows seems not to implement _ReadWriteBarrier neither
(at least we get linker errors there as well).

Regards Hartmut