Pickle-free multiprocessing

caller

import stuff
import multiprocessing
import pickle
from refnx._lib.emcee import EnsembleSampler

nvp = len(objective.varying_parameters())

with multiprocessing.pool.Pool(processes=None, initializer=stuff.initialiser, initargs=(pickle.dumps(objective),)) as pwl:
    sampler = EnsembleSampler(200, nvp, stuff.calculator, pool=pwl)
    %time sampler.run_mcmc(fitter.chain[-1], 4000)
 

stuff.py

import pickle

obj = None

def initialiser(*args):
    global obj 
    obj = pickle.loads(args[0])


def calculator(x):
    return obj.logpost(x)