[Python-checkins] cpython (merge 3.2 -> default): Issue #14308: Fix an exception when a dummy thread is in the threading module's

Fri Apr 20 00:06:44 CEST 2012

http://hg.python.org/cpython/rev/e3ea462cb181
changeset: 76422:e3ea462cb181
parent: 76419:293180d199f2
parent: 76421:41c64c700e1e
user: Antoine Pitrou <solipsis at pitrou.net>
date: Fri Apr 20 00:05:17 2012 +0200
summary:
 Issue #14308: Fix an exception when a dummy thread is in the threading module's active list after a fork().
files:
 Lib/test/test_threading.py | 29 ++++++++++++++++++++++++++
 Lib/threading.py | 3 ++
 Misc/NEWS | 3 ++
 3 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -2,6 +2,8 @@
 
 import test.support
 from test.support import verbose, strip_python_stderr, import_module
+from test.script_helper import assert_python_ok
+
 import random
 import re
 import sys
@@ -415,6 +417,33 @@
 t = threading.Thread(daemon=True)
 self.assertTrue(t.daemon)
 
+ @unittest.skipUnless(hasattr(os, 'fork'), 'test needs fork()')
+ def test_dummy_thread_after_fork(self):
+ # Issue #14308: a dummy thread in the active list doesn't mess up
+ # the after-fork mechanism.
+ code = """if 1:
+ import _thread, threading, os, time
+
+ def background_thread(evt):
+ # Creates and registers the _DummyThread instance
+ threading.current_thread()
+ evt.set()
+ time.sleep(10)
+
+ evt = threading.Event()
+ _thread.start_new_thread(background_thread, (evt,))
+ evt.wait()
+ assert threading.active_count() == 2, threading.active_count()
+ if os.fork() == 0:
+ assert threading.active_count() == 1, threading.active_count()
+ os._exit(0)
+ else:
+ os.wait()
+ """
+ _, out, err = assert_python_ok("-c", code)
+ self.assertEqual(out, b'')
+ self.assertEqual(err, b'')
+
 
 class ThreadJoinOnShutdown(BaseTestCase):
 
diff --git a/Lib/threading.py b/Lib/threading.py
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -871,6 +871,9 @@
 with _active_limbo_lock:
 _active[self._ident] = self
 
+ def _stop(self):
+ pass
+
 def join(self, timeout=None):
 assert False, "cannot join a dummy thread"
 
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -55,6 +55,9 @@
 Library
 -------
 
+- Issue #14308: Fix an exception when a "dummy" thread is in the threading
+ module's active list after a fork().
+
 - Issue #11750: The Windows API functions scattered in the _subprocess and
 _multiprocessing.win32 modules now live in a single module "_winapi".
 Patch by sbt.
-- 
Repository URL: http://hg.python.org/cpython
