[Request] expose identifier for workers

[holymonson]

In multiprocessing, we can use multiprocessing.current_process()._identity to identify worker, and allocate isolated SharedMemory for each worker via initializer().

I wonder if pathos could provide an unified identify for workers in all Pool. So as the initializer parameter (ThreadPool and ProcessPool may have it, but ParallelPool and SerialPool seem not).

[mmckerns]

ThreadPool and ProcessPool do have this option, due to multiprocess -- and you are correct that the other two pools don't. ParallelPool is challenging, as the workers may be on distributed resources. What I tend to do is to pass an additional argument "id" with a unique identifier to the map. It's a workaround, but it enables one to uniquely identify the worker in any pool... and is probably the best approach until there's a mechanism like you mention forProcessPool.

[mmckerns]

So, this is what exists, if you want to work with a ParallelPool and don't want to pass an id

>>> pp = ParallelPool()
>>> s = list(pp.__state__.values())[0]
>>> s._Server__rworkers # 'remote' workers
[]
>>> w = s._Server__workers[0] # local workers
>>> w.pid  # this is the same as multiprocess.current_thread().ident
47242

Then multiprocess.current_thread().ident works for an id for all local workers on any of the pathos pools. I have to look at how to handle remote workers.