Segmentation fault when regridding

[AbhiHampiholi]

Requirements

• Reviewed ESMF Reference Manual
• Searched GitHub Discussions

Affiliation(s)

AirMettle, Inc

ESMF Version

8.6.0

Issue

I am trying to use the ESMC library to regrid tensors obtained from reading NetCDF files. I am running into an issue where the first time I call regrid a file I get the correct expected output. But the second time, I get a segfault. I am running this with ESMF_COMM="mpiuni".

I can provide more specifics but the general structure of the smallest failing example code is

loop 2 times
    ESMC_Initialize(NULL, ESMC_InitArgLogKindFlag(ESMC_LOGKIND_NONE), ESMC_ArgLast);
    //create src grid - fill it up
    //create dest grid - fill it up
    //create src field using ESMC_FieldCreateGridTypeKind - fill up src field
    //create dest field
    //regrid between srcfield and destfield
    //read from destField to get "regridded data"
    ESMC_FieldDestroy(&srcfield);
    ESMC_FieldDestroy(&destfield);
    ESMC_GridDestroy(&srcgrid);
    ESMC_GridDestroy(&destgrid);
    ESMC_Finalize();
end loop

l have made sure to check that the return code is always = ESMF_SUCCESS after each call to an ESMF function. The first iteration of the loop runs perfectly and I get the correct expected output. However, on the second iteration, I get a segmentation fault in ESMC_GridCreateNoPeriDim The arguments that are being passed to ESMC_GridCreateNoPeriDim are identical on both iterations. On investigation with GDB I found that the cause of the segfault is that petCount is incorrectly set to a very large number (instead of 1) in the ESMCI::DELayout::create() function in the line

  // query the VM for localPet and petCount
  int petCount = vm->getNpets();

Any help finding the issue is much appreciated!

Autotag

@oehmke

[danrosen25]

@AbhiHampiholi
We have this documented in the ESMF Fortran Reference Guide but I see that it's not documented in the ESMF C Reference Guide. I know that in Fortran you cannot call ESMF Initialize after Finalize. Try moving the ESMC_Initialize and ESMC_Finalize outside of the loop.

Reproducer
test_268.tgz

[AbhiHampiholi]

Thank you for the clarification @danrosen25 ! I confirmed that ensuring that no ESMC function gets called after the finalize fixes the issue.