vine: nonblocking manager.wait() doesn't return results

[tphung3]

Description: Setting the result wait time of the manager to 0 results in a hanging behavior in the application.

Desired behavior: The application should not hang but instead keep going to the end, per

cctools/taskvine/src/bindings/python3/ndcctools/taskvine/manager.py

Line 1086 in baaf877

# If 0, return immediately with a complete task if one available, or None otherwise.

.

How to reproduce: set this wait time to 0 in probably any test in taskvine/test to reproduce the issue. I observed this issue with taskvine/test/vine_python_serverless.py and taskvine/test/vine_python_task.py

[btovar]

Does it hang or busy waits? Looking at the code, it should be busy waiting. When wait time is zero the manager returns immediately with a task already retrieved. Is this a bug with the code or the documentation?

[tphung3]

I think this is a bug. If there's a test with m.wait(0), the worker for that test will time out because of no work sent.

[btovar]

Is the bug with the test that calls m.wait(0)? What are your intentions for calling wait(0) instead of using a timeout larger than 0?