Re: Pure Python IOC (CAProcess issue)

[Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov>]

On 7/17/20 9:33 AM, Michael Davidsaver wrote:
> The python subprocess module shouldn't let this happen though since it does
> fork() and then execv(), and the situation which I describe is only possible
> if fork() is not followed by execv().

Oh wait.  CAProcess (which I've not seen previously) is using
the multiprocessing module, which can do fork() without exec().
In fact, this is the default on *NIX.  So this is likely or
problem.  I think you'll need to use the 'spawn' or 'forkserver'
method.

https://docs.python.org/3.7/library/multiprocessing.html#contexts-and-start-methods

https://github.com/pyepics/pyepics/blob/1f795c647458435cca0cf11b984b34fc11180c25/epics/multiproc.py