tmp changes

Author: Vahid Tavanashad

mkl_fft/interfaces/_scipy_fft.py

@@ -32,7 +32,6 @@
 import contextlib
 import contextvars
 import operator
-import os
 from numbers import Number
 
 import mkl
@@ -101,7 +100,8 @@ def _workers_to_num_threads(w):
     if _w == 0:
         raise ValueError("Number of workers must not be zero")
     if _w < 0:
-        _cpu_count = os.cpu_count()
+        # SciPy uses os.cpu_count()
+        _cpu_count = mkl.get_max_threads()  # pylint: disable=no-member
         _w += _cpu_count + 1
         if _w <= 0:
             raise ValueError(

mkl_fft/tests/third_party/scipy/test_multithreading.py

@@ -4,6 +4,7 @@
 import multiprocessing
 import os
 
+import mkl
 import numpy as np
 import pytest
 from numpy.testing import assert_allclose
@@ -80,22 +81,26 @@ def test_invalid_workers(x):
 
 
 def test_set_get_workers():
-    cpus = os.cpu_count()
+    # cpus = os.cpu_count()
+    threads = mkl.get_max_threads()  # pylint: disable=no-member
+    # cpus and threads are usually the same but in CI, cpus = 4 and threads = 2
+    # SciPy uses `os.cpu_count()` to get the number of workers, while
+    # `mkl_fft.interfaces.scipy_fft` uses `mkl.get_max_threads()`
 
     # default value is max number of threads unlike stock SciPy
-    assert fft.get_workers() == cpus
+    assert fft.get_workers() == threads
     with fft.set_workers(4):
         assert fft.get_workers() == 4
 
         with fft.set_workers(-1):
-            assert fft.get_workers() == cpus
+            assert fft.get_workers() == threads
 
         assert fft.get_workers() == 4
 
     # default value is max number of threads unlike stock SciPy
-    assert fft.get_workers() == cpus
+    assert fft.get_workers() == threads
 
-    with fft.set_workers(-cpus):
+    with fft.set_workers(-threads):
         assert fft.get_workers() == 1