[Users] Code failure apparently due to changes in Reduction.c

[Yosef Zlochower]

Thanks. One final question, when using CCTK_Reduce, which should we use 
CCTK_ReductionArrayHandle to get the handle?


On 8/17/21 3:01 PM, Roland Haas wrote:
> Hello Yosef,
>
>> We were using Carpet and the actual call was to
>>
>> CCTK_ReduceLocArrayToArray1D
>>
>> Is this valid in Carpet?
> No, unfortunately this is not valid in Carpet.
>
> For two reasons actually:
>
> The combination CCTK_LocalArrayReductionHandle and
> CCTK_ReduceLocArrayToArray1D is never valid, since CCTK_LocalArrayReductionHandle  is "new" interface, while
> CCTK_ReduceLocArrayToArray1D is "old" interface. You can see it among
> the list of functions in my previous email.
>
> Further "CCTK_LocalArrayReductionHandle", being "new" interface, is
> never valid for Carpet, since Carpet only supports the "old" interface.
>
> So "no", "no".
>
> "CCTK_ReduceLocArrayToArray1D" however is "old" interface, so is valid
> with Carpet, but you must use "CCTK_ReductionArrayHandle" to get the
> reduction handle for it. You must *not* use "CCCTK_ReductionHandle" or
> "CCTK_LocalArrayReductionHandle" to get a handle to use with
> "CCTK_ReduceLocArrayToArray1D".
>
> Nope this helps. The functions names a confusing, unfortunately, and the
> fact that the "old" interface, which is the only one Carpet supports,
> is not fully documented in the CCTK reference anymore, does not really
> help.
>
> Yours,
> Roland
>
>> On 8/17/21 12:59 PM, Roland Haas wrote:
>>> Hello Yosef,
>>>
>>> there's a couple different reduction interfaces and the handle you get
>>> must match.
>>>
>>> It depends a bit on the drive you are using.
>>>
>>> Carpet only supports the "old style" reduction interface that uses:
>>>
>>> CCTK_Reduce
>>> CCTK_ReductionHandle
>>>
>>> CCTK_ReduceLocalScalar
>>> CCTK_ReductionArrayHandle
>>> and:
>>> CCTK_ReduceArray
>>> CCTK_ReduceLocalArray1D
>>>
>>> it does not support the new interface CCTK_LocalArrayReductionHandle at
>>> all.
>>>
>>> PUGH supports the new one and (I think) the old one as well. The new
>>> one uses:
>>>
>>> CTK_LocalArrayReductionHandle
>>> CCTK_ReduceLocalArrays
>>>
>>> See
>>> https://urldefense.com/v3/__https://www.einsteintoolkit.org/referencemanual/ReferenceManual.html*x1-1000A__;Iw!!DZ3fjg!vO69j0_NDEC1JMkgMyZSdz57Nk1EjyHTBh3FU214vo8W15081AZ6_X93p6b5_AlO$  and search for A488.
>>>
>>> So are you using this with PUGH or Carpet? With Carpet it must fail (not
>>> supported at all), with PUGH it should work as long as you sue the
>>> correct set of calls ie CCTK_LocalArrayReductionHandle +
>>> CCTK_ReduceLocalArrays (for PUGH only).
>>>
>>> Yours,
>>> Roland
>>>   
>>>> Hi,
>>>>
>>>>     A code that we are using seems to no longer work with Cactus. The
>>>> issue seems to be that the code called CCTK_LocalArrayReductionHandle.
>>>> The code, as checked out, produces errors because the appropriate handle
>>>> isn't found. If I modify the function as below,  I no longer get the
>>>> error message
>>>>
>>>>
>>>>
>>>> int CCTK_LocalArrayReductionHandle(const char *reduction)
>>>> {
>>>>      int handle;
>>>>
>>>>
>>>>      handle = Util_GetHandle(LocalArrayReductionOperators, reduction, NULL);
>>>>      if (handle < 0)
>>>>      {
>>>>        CCTK_VWarn(1,__LINE__,__FILE__,"Cactus",
>>>>                   "CCTK_LocalArrayReductionHandle: No handle: '%d' found
>>>> for reduction operator "
>>>>                   "'%s'", handle, reduction);
>>>>      }
>>>>
>>>>      handle += ARRAY_OPERATOR_HANDLE_OFFSET; //// MY changes
>>>>
>>>>      return handle;
>>>> }
>>>>
>>>>
>>>> Should we no longer use CCTK_LocalArrayReductionHandle?
>>>>   
>>>   
>
>
-- 
Dr. Yosef Zlochower
Center for Computational Relativity and Gravitation
Associate Professor
School of Mathematical Sciences
Rochester Institute of Technology
85 Lomb Memorial Drive
Rochester, NY 14623

Office:74-2067
Phone: +1 585-475-6103

yosef at astro.rit.edu

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