Re: string and __thread

[Benjamin Kosnik <bkoz at redhat dot com>]

>Obviously we want experience, which is why I posted.  The problem
>is well-known, and has been belabored at length in the literature,
>e.g. Herb Sutter's benchmarks.  

Perhaps you could consider adding this in the 21_strings
documentation as part of your patch below? I'd appreciate it. 

>As it happens, the alternative suggestion I had mentioned doesn't
>need special linker/loader support, and already has industrial 
>demonstration: it's used in the Rogue Wave library.  Furthermore, 
>it can sometimes improve performance even in single-CPU contexts.  
>Best of all, it's obviously non-disruptive.

Sounds like a much better approach.

>That alternative is to test the pointer for equality to the known
>empty-string object before doing an increment or decrement-and-test.
>I will prepare a patch if Paolo doesn't get to it first.

Looking forward to your patch. 

I suspect when it's posted, and people actually have something in hand,
you'll see more wilingness to experiment with it and give feedback on MT
apps under heavy load.

best,
benjamin