Issue 19158: a rare race in BoundedSemaphore could allow .release() too often.
(grafted from e06edc0c7a4951327f0c95ebeebccba6879a6063)
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 5a765f3..ac0b4bc 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -466,6 +466,23 @@
finally:
sys.setcheckinterval(old_interval)
+ def test_BoundedSemaphore_limit(self):
+ # BoundedSemaphore should raise ValueError if released too often.
+ for limit in range(1, 10):
+ bs = threading.BoundedSemaphore(limit)
+ threads = [threading.Thread(target=bs.acquire)
+ for _ in range(limit)]
+ for t in threads:
+ t.start()
+ for t in threads:
+ t.join()
+ threads = [threading.Thread(target=bs.release)
+ for _ in range(limit)]
+ for t in threads:
+ t.start()
+ for t in threads:
+ t.join()
+ self.assertRaises(ValueError, bs.release)
class ThreadJoinOnShutdown(BaseTestCase):