0.29.16

set_start_method()

Author: bartzbeielstein

pyproject.toml

@@ -7,7 +7,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "spotpython"
-version = "0.29.15"
+version = "0.29.16"
 authors = [
   { name="T. Bartz-Beielstein", email="tbb@bartzundbartz.de" }
 ]

src/spotpython/spot/spot.py

@@ -8,7 +8,7 @@
 import json
 from numpy.random import default_rng
 from spotpython.design.spacefilling import SpaceFilling
-from multiprocessing import set_start_method
+from multiprocessing import set_start_method, get_start_method
 
 # old Kriging with attribute "name" kriging
 from spotpython.build.kriging import Kriging as OldKriging
@@ -56,9 +56,6 @@
 # matplotlib.use("TkAgg")
 # matplotlib.use("Agg")
 
-# for multiprocessing:
-set_start_method("spawn")
-
 logger = logging.getLogger(__name__)
 # configure the handler and formatter as needed
 py_handler = logging.FileHandler(f"{__name__}.log", mode="w")
@@ -205,6 +202,13 @@ def __init__(
         self.optimizer_control = optimizer_control
         self.surrogate_control = surrogate_control
 
+        # for multiprocessing:
+        # check if context is already set to "spawn"
+        # if not, set it to "spawn"
+        # Check if the context is already set to "spawn"
+        if get_start_method(allow_none=True) != "spawn":
+            set_start_method("spawn", force=True)
+
         # small value:
         self.eps = sqrt(spacing(1))
 

test/test_multiprocess.py

@@ -0,0 +1,15 @@
+from multiprocessing import get_start_method, set_start_method
+
+def test_multiprocessing_context_spawn():
+    """
+    Test that the multiprocessing context is set to 'spawn' if it is not already set.
+    """
+    # Check the current start method
+    current_method = get_start_method(allow_none=True)
+
+    # If the current method is not 'spawn', set it to 'spawn'
+    if current_method != "spawn":
+        set_start_method("spawn", force=True)
+
+    # Verify that the start method is now 'spawn'
+    assert get_start_method() == "spawn", "The multiprocessing context should be set to 'spawn'."