Messages

16

General Discussion about just::thread / Re: sequential consistency for std::atomic on x86

« on: January 27, 2011, 08:17:53 AM »

Yes, plain loads have acquire semantics and plain stores have release semantics on x86. Note that actually, the ordering on the data variable are superfluous and could be replaced with std::memory_order_relaxed: the operations on ready are sufficient to guarantee the ordering.

Hi Anthony.

Does it mean that fences are completely unneccessary on x86? In the article mentioned above I can see this

There must be algorithms that require fences even on the x86.

and there are mfence, sfence and lfence instructions available on x86. How does your library work if it doesn't use them and where they are used? Could you please explain this in more details?

Thanks.

17

General Discussion about just::thread / Re: Tried for you... gcc 4.5.1, Aug 31 gcc 4.6

« on: December 17, 2010, 09:57:02 AM »

The current release supports gcc 4.5 (if you install the right .debs); older releases did not, and the message was correct when written. I guess I ought to update the readme and documentation.

Thanks.

18

General Discussion about just::thread / Re: std::kill_dependency

« on: December 17, 2010, 09:55:04 AM »

The dependency ordering stuff only matters where memory_order_consume is distinct from memory_order_acquire. This is not the case for x86 systems, which is the only type of processor currently supported by just::thread. std::kill_dependency is thus a no-op, and is provided for completeness only.

Ah OK..I didn't think about that, thanks.

19

General Discussion about just::thread / std::kill_dependency

« on: December 16, 2010, 05:34:13 PM »

Hi Anthony,

It was interesting to me how does std::kill_dependency implemented and I looked at the code of this function..It looks pretty much interesting. Does it really kill the dependency or it is provided just to support standard?

Thanks.

20

General Discussion about just::thread / Re: Tried for you... gcc 4.5.1, Aug 31 gcc 4.6

« on: December 16, 2010, 05:01:15 PM »

And just for clarity: just::thread does not support g++ 4.5 or later in the current release.

Hi Anthony,

Compatible with g++ 4.3, 4.4 and 4.5 for 32-bit and 64-bit Ubuntu linux (x86/x86_64) targets, making full use of the C++0x support from g++ including rvalue references and variadic templates.

http://www.stdthread.co.uk/
On the other hand my documentation said

Compatible with g++ 4.3 and g++ 4.4 for 32-bit and 64-bit Ubuntu linux targets.

Nothing about gcc 4.5.
Which information is more correct?

BTW, readme.txt from my copy says "The just::thread C++ Thread Library v1.0", while there is announcement of V1.3 as a last version
http://www.stdthread.co.uk/forum/index.php/topic,73.0.html
As far as I see that is the latest version, you probably forgot to update readme.txt

Thanks.