Use mp_ctx forkserver on MacOS

pymc-devs · Jul 6, 2020 · 8f14987 · 8f14987
1 parent 8e8bd86
commit 8f14987
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Showing 2 changed files with 4 additions and 6 deletions.
diff --git a/pymc3/__init__.py b/pymc3/__init__.py
@@ -27,12 +27,6 @@
         handler = logging.StreamHandler()
         _log.addHandler(handler)
 
-# Set start method to forkserver for MacOS to enable multiprocessing
-# Closes issue https://github.com/pymc-devs/pymc3/issues/3849
-sys = platform.system()
-if sys == "Darwin":
-    new_context = mp.get_context("forkserver")
-
 
 def __set_compiler_flags():
     # Workarounds for Theano compiler problems on various platforms

diff --git a/pymc3/parallel_sampling.py b/pymc3/parallel_sampling.py
@@ -20,6 +20,7 @@
 import pickle
 from collections import namedtuple
 import traceback
+import platform
 from pymc3.exceptions import SamplingError
 
 import numpy as np
@@ -420,6 +421,9 @@ def __init__(
             raise ValueError("Number of seeds and start_points must be %s." % chains)
 
         if mp_ctx is None or isinstance(mp_ctx, str):
+            # Closes issue https://github.com/pymc-devs/pymc3/issues/3849
+            if platform.system() == 'Darwin':
+                mp_ctx = "forkserver"
             mp_ctx = multiprocessing.get_context(mp_ctx)
 
         step_method_pickled = None