From b4222fd0b89d7ad736e8401b97d936087c6aff67 Mon Sep 17 00:00:00 2001 From: Brian Quinlan Date: Tue, 7 May 2019 15:22:31 -0400 Subject: [PATCH 1/2] bpo-31783: Fix a race condition while creating workers during interpreter shutdown --- Lib/concurrent/futures/thread.py | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/Lib/concurrent/futures/thread.py b/Lib/concurrent/futures/thread.py index 2af31a106dd914..6aab7c8ee2e3bf 100644 --- a/Lib/concurrent/futures/thread.py +++ b/Lib/concurrent/futures/thread.py @@ -29,10 +29,14 @@ _threads_queues = weakref.WeakKeyDictionary() _shutdown = False +# Lock that ensures that new workers are not created while the interpreter is +# shutting down. Must be held while mutating _threads_queues and _shutdown. +_global_shutdown_lock = threading.Lock() def _python_exit(): global _shutdown - _shutdown = True + with _global_shutdown_lock: + _shutdown = True items = list(_threads_queues.items()) for t, q in items: q.put(None) @@ -158,7 +162,7 @@ def submit(*args, **kwargs): raise TypeError('submit expected at least 1 positional argument, ' 'got %d' % (len(args)-1)) - with self._shutdown_lock: + with self._shutdown_lock, _global_shutdown_lock: if self._broken: raise BrokenThreadPool(self._broken) From e1f0027127dd434d432055c8095cc4aa1567231c Mon Sep 17 00:00:00 2001 From: "blurb-it[bot]" Date: Tue, 7 May 2019 19:25:56 +0000 Subject: [PATCH 2/2] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?= =?UTF-8?q?rb=5Fit.?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../NEWS.d/next/Library/2019-05-07-19-25-55.bpo-31783.lgLo69.rst | 1 + 1 file changed, 1 insertion(+) create mode 100644 Misc/NEWS.d/next/Library/2019-05-07-19-25-55.bpo-31783.lgLo69.rst diff --git a/Misc/NEWS.d/next/Library/2019-05-07-19-25-55.bpo-31783.lgLo69.rst b/Misc/NEWS.d/next/Library/2019-05-07-19-25-55.bpo-31783.lgLo69.rst new file mode 100644 index 00000000000000..a261e59ccfecd8 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-05-07-19-25-55.bpo-31783.lgLo69.rst @@ -0,0 +1 @@ +Fix race condition in ThreadPoolExecutor when worker threads are created during interpreter shutdown. \ No newline at end of file