Add test for freethreading

Author: oscarbenjamin

meson.build

@@ -83,6 +83,12 @@ add_project_arguments(
     language : 'cython'
 )
 
+# Enable free-threading if Cython is new enough:
+#cy = meson.get_compiler('cython')
+#if cy.version().version_compare('>=3.1.0')
+#    add_project_arguments('-Xfreethreading_compatible=true', language : 'cython')
+#endif
+
 if get_option('coverage')
    add_project_arguments('-X', 'linetrace=True', language : 'cython')
    add_project_arguments('-DCYTHON_TRACE=1', language : 'c')

src/flint/test/test_all.py

@@ -1612,10 +1612,12 @@ def set_bad2():
     M6 = M6_copy
     assert M6.nullspace() == (M([[1,15,1],[0,0,0],[0,0,0]],17).transpose(), 1)
 
+
 def test_nmod_series():
     # XXX: currently no code in nmod_series.pyx
     pass
 
+
 def test_arb():
     A = flint.arb
     assert A(3) > A(2.5)
@@ -1626,6 +1628,7 @@ def test_arb():
     assert A(3) != A(2)
     assert not (A("1.1") == A("1.1"))
 
+
 def test_pickling():
     objects = [
         flint.fmpz(1),
@@ -4735,6 +4738,39 @@ def test_fq_default_poly():
         assert raises(lambda: f.pow_trunc(-1, 5), ValueError)
 
 
+def test_python_threads():
+
+    from threading import Thread
+
+    iterations = 10**5
+    threads = 3 + 1
+    size = 3
+    M = flint.fmpz_mat([[0]*size for _ in range(size)])
+
+    def set_values():
+        for i in range(iterations // 5):
+            i = random.randrange(M.nrows())
+            j = random.randrange(M.ncols())
+            if random.uniform(0, 1) > 0.5:
+                # Bigger than 2**62:
+                M[i,j] = 10**128
+            else:
+                # Smaller than 2**62:
+                M[i,j] = 0
+
+    def get_dets():
+        for i in range(iterations):
+            M.det()
+
+    threads = [Thread(target=set_values) for _ in range(threads-1)]
+    threads.append(Thread(target=get_dets))
+
+    for t in threads:
+        t.start()
+    for t in threads:
+        t.join()
+
+
 def test_all_tests():
     test_funcs = {f for name, f in globals().items() if name.startswith("test_")}
     untested = test_funcs - set(all_tests)
@@ -4813,5 +4849,7 @@ def test_all_tests():
 
     test_pickling,
 
+    test_python_threads,
+
     test_all_tests,
 ]