concurrent use of in_memory workspace in arcpy

Question

i am using a python script that's eliminating small polygons from a feature class. this script creates temporary feature classes with fixed (hardcoded) names in the "in_memory" workspace. example:

arcpy.CopyFeatures_management("in_fc","in_memory/item_a")

it's a fairly reusable script, so i use it at many points in a geoprocessing chain.

am i in danger, that the same script called twice from different processes (at the same time) will have a conflict at, for example "in_memory/item_a" ? or are the "in_memory" workspaces seperate for each process?

i am using ArcInfo 10.0.

Answer 1

To test out your question, I wrote up a quick script that I ran two copies of simultaneously- one as a script tool in ArcMap and one in Pythonwin. Somewhat to my surprise, I was unable to run them at the same time because the "in_memory" workspace was shared. There is a way around this, however. You can add in an output check to determine if the file in memory exists, and name it something else if so:

i=0
check = 0
while check == 0:
    memoryFeat = "in_memory" + "\\" + "testMemoryFeature" + str(i)
    if arcpy.Exists(memoryFeat):
        i+=1
    else:
        check = 1

This will attempt to name your in memory feature testMemoryFeature0. If that memory feature already exists, it will attempt to name it testMemoryFeature1, and so on until it finds a name that will suffice.