Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/scipy/fft/tests/test_multithreading.py

@@ -0,0 +1,83 @@
+from scipy import fft
+import numpy as np
+import pytest
+from numpy.testing import assert_allclose
+import multiprocessing
+import os
+
+
+@pytest.fixture(scope='module')
+def x():
+    return np.random.randn(512, 128)  # Must be large enough to qualify for mt
+
+
+@pytest.mark.parametrize("func", [
+    fft.fft, fft.ifft, fft.fft2, fft.ifft2, fft.fftn, fft.ifftn,
+    fft.rfft, fft.irfft, fft.rfft2, fft.irfft2, fft.rfftn, fft.irfftn,
+    fft.hfft, fft.ihfft, fft.hfft2, fft.ihfft2, fft.hfftn, fft.ihfftn,
+    fft.dct, fft.idct, fft.dctn, fft.idctn,
+    fft.dst, fft.idst, fft.dstn, fft.idstn,
+])
+@pytest.mark.parametrize("workers", [2, -1])
+def test_threaded_same(x, func, workers):
+    expected = func(x, workers=1)
+    actual = func(x, workers=workers)
+    assert_allclose(actual, expected)
+
+
+def _mt_fft(x):
+    return fft.fft(x, workers=2)
+
+
+def test_mixed_threads_processes(x):
+    # Test that the fft threadpool is safe to use before & after fork
+
+    expect = fft.fft(x, workers=2)
+
+    with multiprocessing.Pool(2) as p:
+        res = p.map(_mt_fft, [x for _ in range(4)])
+
+    for r in res:
+        assert_allclose(r, expect)
+
+    fft.fft(x, workers=2)
+
+
+def test_invalid_workers(x):
+    cpus = os.cpu_count()
+
+    fft.ifft([1], workers=-cpus)
+
+    with pytest.raises(ValueError, match='workers must not be zero'):
+        fft.fft(x, workers=0)
+
+    with pytest.raises(ValueError, match='workers value out of range'):
+        fft.ifft(x, workers=-cpus-1)
+
+
+def test_set_get_workers():
+    cpus = os.cpu_count()
+    assert fft.get_workers() == 1
+    with fft.set_workers(4):
+        assert fft.get_workers() == 4
+
+        with fft.set_workers(-1):
+            assert fft.get_workers() == cpus
+
+        assert fft.get_workers() == 4
+
+    assert fft.get_workers() == 1
+
+    with fft.set_workers(-cpus):
+        assert fft.get_workers() == 1
+
+
+def test_set_workers_invalid():
+
+    with pytest.raises(ValueError, match='workers must not be zero'):
+        with fft.set_workers(0):
+            pass
+
+    with pytest.raises(ValueError, match='workers value out of range'):
+        with fft.set_workers(-os.cpu_count()-1):
+            pass