Possible race condition in gluon.admin.create_missing_folders

[Anthony]

I encountered an interesting problem when the Travis-CI build ran after I pushed a commit to the TechEmpower FrameworkBenchmarks repo. In gluon.admin.create_missing_folders, each of two Meinheld workers generated a File exists: '.../web2py/deposit' error. The relevant code is:

            if not os.path.exists(path):
                os.mkdir(path)

I've run the tests many times via the VM with no problem, and I immediately re-ran the Travis-CI build and it passed, so I'm assuming this was a (hopefully rare) race condition, with both workers attempting to create the /deposit directory after confirming it does not exist.

Perhaps we should instead wrap os.mkdir in a try/except. Would probably need to do the same thing in create_missing_app_folders (and maybe in some other places).

Thoughts?

If we push a commit to fix this, I can update the benchmarking setup code to point to the latest commit so we don't run into this problem when they run the real tests.

Anthony

[Anthony]

I went ahead and made a pull request: https://github.com/web2py/web2py/pull/1448