Issue #9670: Increase the default stack size for secondary threads on

Mac OS X and FreeBSD to reduce the chances of a crash instead of a
"maximum recursion depth" RuntimeError exception.
(patch by Ronald Oussoren)

1 files changed, 31 insertions, 0 deletions

diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 0062634f7e..946c1d2b7c 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -689,6 +689,37 @@ class SemaphoreTests(lock_tests.SemaphoreTests):
 class BoundedSemaphoreTests(lock_tests.BoundedSemaphoreTests):
     semtype = staticmethod(threading.BoundedSemaphore)
 
+    @unittest.skipUnless(sys.platform == 'darwin', 'test macosx problem')
+    def test_recursion_limit(self):
+        # Issue 9670
+        # test that excessive recursion within a non-main thread causes
+        # an exception rather than crashing the interpreter on platforms
+        # like Mac OS X or FreeBSD which have small default stack sizes
+        # for threads
+        script = """if True:
+            import threading
+
+            def recurse():
+                return recurse()
+
+            def outer():
+                try:
+                    recurse()
+                except RuntimeError:
+                    pass
+
+            w = threading.Thread(target=outer)
+            w.start()
+            w.join()
+            print('end of main thread')
+            """
+        expected_output = "end of main thread\n"
+        p = subprocess.Popen([sys.executable, "-c", script],
+                             stdout=subprocess.PIPE)
+        stdout, stderr = p.communicate()
+        data = stdout.decode().replace('\r', '')
+        self.assertEqual(p.returncode, 0, "Unexpected error")
+        self.assertEqual(data, expected_output)
 
 def test_main():
     test.test_support.run_unittest(LockTests, RLockTests, EventTests,