python · zhangyangyu · Feb 27, 2017 · Feb 27, 2017
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
@@ -170,6 +170,9 @@ def f(mutex):
        mutex.acquire()
        self.assertIn(tid, threading._active)
        self.assertIsInstance(threading._active[tid], threading._DummyThread)
+        #Issue 29376
+        self.assertTrue(threading._active[tid].is_alive())
+        self.assertRegex(repr(threading._active[tid]), '_DummyThread')
        del threading._active[tid]

    # PyThreadState_SetAsyncExc() is a CPython-only gimmick, not (currently)

diff --git a/Lib/threading.py b/Lib/threading.py
@@ -1215,6 +1215,10 @@ def __init__(self):
    def _stop(self):
        pass

+    def is_alive(self):
+        assert not self._is_stopped and self._started.is_set()
+        return True
+
    def join(self, timeout=None):
        assert False, "cannot join a dummy thread"


diff --git a/Misc/NEWS b/Misc/NEWS
@@ -32,6 +32,8 @@ Extension Modules
 Library
 -------

+- bpo-29376: Fix assertion error in threading._DummyThread.is_alive().
+
 - bpo-29110: Fix file object leak in aifc.open() when file is given as a
  filesystem path and is not in valid AIFF format. Patch by Anthony Zhang.