use mktempdir for regridding

experiments/ClimaEarth/user_io/io_helpers.jl

@@ -1,9 +1,11 @@
 # helpers with boiler plate code for IO operations, useful for all ClimaEarth drivers.
 
 """
-    setup_output_dirs(; output_dir = nothing, regrid_dir = nothing, artifacts_dir = nothing, comms_ctx)
+    setup_output_dirs(; output_dir = nothing, artifacts_dir = nothing, comms_ctx)
 
 Create output directories for the experiment. If `comms_ctx` is provided, only the root process will create the directories.
+By default, the regrid directory is created as a temporary directory inside the output directory,
+and the artifacts directory is created inside the output directory with the suffix `_artifacts`.
 
 # Arguments
 - `output_dir::String`: The directory where the output files will be stored. Default is the current directory.
@@ -14,28 +16,24 @@ Create output directories for the experiment. If `comms_ctx` is provided, only t
 # Returns
 - A tuple with the paths to the output, regrid, and artifacts directories.
 """
-function setup_output_dirs(; output_dir = nothing, regrid_dir = nothing, artifacts_dir = nothing, comms_ctx)
+function setup_output_dirs(; output_dir = nothing, artifacts_dir = nothing, comms_ctx)
     if output_dir === nothing
         output_dir = "."
     end
-    if regrid_dir === nothing
-        regrid_dir = joinpath(output_dir, "regrid_tmp/")
-    end
     if artifacts_dir === nothing
         artifacts_dir = output_dir * "_artifacts"
     end
 
     @info(output_dir)
+    regrid_dir = nothing
     if ClimaComms.iamroot(comms_ctx)
         mkpath(output_dir)
-        mkpath(regrid_dir)
         mkpath(artifacts_dir)
+        regrid_dir = mktempdir(output_dir, prefix = "regrid_tmp_")
     end
-
-    ClimaComms.barrier(comms_ctx)
+    regrid_dir = ClimaComms.bcast(comms_ctx, regrid_dir)
 
     return (; output = output_dir, artifacts = artifacts_dir, regrid = regrid_dir)
-
 end
 
 """

src/Regridder.jl

@@ -184,8 +184,6 @@ function hdwrite_regridfile_rll_to_cgll(
         space_undistributed = space2d_undistributed
     end
     if isfile(datafile_cgll) == false
-        isdir(REGRID_DIR) ? nothing : mkpath(REGRID_DIR)
-
         nlat, nlon = NCDatasets.NCDataset(datafile_rll) do ds
             (ds.dim["lat"], ds.dim["lon"])
         end

test/mpi_tests/regridder_mpi_tests.jl

@@ -15,8 +15,6 @@ import ClimaCoupler: Regridder
 include(joinpath("..", "TestHelper.jl"))
 import .TestHelper
 
-REGRID_DIR = @isdefined(REGRID_DIR) ? REGRID_DIR : joinpath("", "regridder_test_tmp/")
-
 # Set up MPI communications context
 # Note that runs will hang if a context is initialized twice in the same file,
 # so this context should be shared among all tests in this file.
@@ -26,8 +24,12 @@ pid, nprocs = ClimaComms.init(comms_ctx)
 
 @testset "test write_to_hdf5 and read_from_hdf5 with MPI" begin
     for FT in (Float32, Float64)
-        # Set up testing directory
-        mkpath(REGRID_DIR)
+        # Create temporary regrid directory on root process and broadcast
+        regrid_dir = nothing
+        if ClimaComms.iamroot(comms_ctx)
+            regrid_dir = mktempdir(pwd(), prefix = "regrid_tmp_")
+        end
+        regrid_dir = ClimaComms.bcast(comms_ctx, regrid_dir)
 
         hd_outfile_root = "hdf5_out_test"
         tx = Dates.DateTime(1979, 01, 01, 01, 00, 00)
@@ -36,14 +38,10 @@ pid, nprocs = ClimaComms.init(comms_ctx)
         varname = "testdata"
 
         ClimaComms.barrier(comms_ctx)
-        Regridder.write_to_hdf5(REGRID_DIR, hd_outfile_root, tx, input_field, varname, comms_ctx)
+        Regridder.write_to_hdf5(regrid_dir, hd_outfile_root, tx, input_field, varname, comms_ctx)
 
         ClimaComms.barrier(comms_ctx)
-        output_field = Regridder.read_from_hdf5(REGRID_DIR, hd_outfile_root, tx, varname, comms_ctx)
+        output_field = Regridder.read_from_hdf5(regrid_dir, hd_outfile_root, tx, varname, comms_ctx)
         @test parent(input_field) == parent(output_field)
-
-        ClimaComms.barrier(comms_ctx)
-        ClimaComms.iamroot(comms_ctx) && rm(REGRID_DIR; recursive = true, force = true)
-        ClimaComms.barrier(comms_ctx)
     end
 end