Re: [boost] Interest in atomic library?

Subject: Re: [boost] Interest in atomic library?
From: Kenny Riddile (kfriddile_at_[hidden])
Date: 2009-04-22 21:13:14

Seth LaForge wrote:
> In this day and age, running our C++ programs off fossil fuels makes a
> dangerous contribution to global warming and requires purchase of
> carbon offsets for ethical programming.  Thus I think it's time for a
> Boost atomic power library.  Oops, sorrry, wrong meaning of atomic.
> 
> What would people think of an atomic integer library, along the lines
> of Linux's asm/atomic.h?  I'd propose a class atomic<T> implementing
> operations like atomic read (implicit conversion to T), atomic set
> (assignment from T), and compare-and-exchange.  For integral types it
> would support atomic add and return result (operator+=), atomic
> subtract and return result (operator-=), atomic increment and return
> result (prefix operator++), and atomic decrement and return result
> (prefix operator--).
> 
> For arbitrary architectures or unhandled types of T, there would be a
> naive implementation using a mutex.  On supported architectures there
> would be specializations for integral T types, using assembly to
> implement more efficient atomic operations.  This assembly could
> pretty much just be borrowed from the Linux asm/atomic.h headers.
> 
> What do people think?  I see pros:
>   + Cross-platform efficient atomic operations for efficient threaded apps.
> I see cons:
>   - Hard to predict whether your atomic ops will be efficient (no
> specialization for your architecture/T).
>   - Some architectures may implement different atomic ops, making the
> above ops not the most efficient.
> 
> I think the pros outweight the cons.  I'd personally much rather use a
> Boost.atomic library than asm/atomic.h.
> 
> Seth
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Intel's TBB has an atomic<T>

http://www.threadingbuildingblocks.org/file.php?fid=77