Charm++ parallel programming system

[Tom Quinn <trq AT astro.washington.edu>]

Are you sure this works if the reducers are running on the same chare 
array?  In ChaNGa we had to set up "shadow arrays" to have two reductions 
running concurrently.

Tom Quinn       Astronomy, University of Washington
Internet:       
trq AT astro.washington.edu
Phone:          206-685-9009

On Tue, 19 Jul 2016, Phil Miller wrote:

> On Tue, Jul 19, 2016 at 9:08 AM, Jozsef Bakosi 
> <jbakosi AT gmail.com>
>  wrote:
>       I have been successfully using custom reducers, described in
>       16.2 of the user manual. Now I'm wondering if it is safe to use
>       more than one reducer, utilizing the same reducer type,
>       registered in the initnode routine, at the same time, i.e.,
>       potentially doing two (or more) reductions running at the same
>       time but whose end-points, of course, point to different
>       reduction entry method member functions. Or do I have to create
>       multiple reducers as the manual example would require a
>       sumTwoShortsType2?
>
>
> The registration of custom reducers is just to associate a common global
> index to t he function pointer that may differ across processes. So go right
> ahead, and it should work fine.
>
> The only case I can think of where multiple concurrent uses of a reducer
> could be a problem is if the reducer implementation contained `static`
> variables, which would seem quite strange.