Error Code Handling in Multiprocessing Tests
Created originally on Bitbucket by andrewjlawrence (Andrew Lawrence)
There is some behavior of error codes that I cannot explain in test_multiprocessing_spawn.py.
When running the tests lib-python\3\test\test_multiprocessing_spawn.py WithManagerTestLock.test_lock WithProcessesTestBarrier.test_barrier on Windows the error code leaks from test_lock into test_barrier causing test_barrier to fail.
In CPython the error codes do not leak between the tests like this.
I have also noticed that doing p _winapi.GetLastError() from pdb inside WithProcessesTestBarrier.test_barrier in CPython produces the error code from the previous test but print(_winapi.GetLastError()) in the test itself does not result in the error.
Also inserting the following code into _test_multiprocessing.py results in different behaviour on both CPython and windows when running test_multiprocessing_spawn.py WithManagerTestLock.test_lock
class ManagerMixin(object): def tearDownClass(cls): import ctypes ctypes.windll.kernel32.SetLastError(996) print(_winapi.GetLastError()) print(ctypes.windll.kernel32.GetLastError())
The final print statement produces 0 in CPython and 996 in PyPy