From 242c26f53edb965e9808dd918089e664c0223407 Mon Sep 17 00:00:00 2001 From: Brian Quinlan Date: Fri, 28 Jun 2019 11:54:52 -0700 Subject: bpo-31783: Fix a race condition creating workers during shutdown (#13171) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * bpo-31783: Fix a race condition while creating workers during interpreter shutdown * 📜🤖 Added by blurb_it. --- Lib/concurrent/futures/thread.py | 8 ++++++-- Misc/NEWS.d/next/Library/2019-05-07-19-25-55.bpo-31783.lgLo69.rst | 1 + 2 files changed, 7 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2019-05-07-19-25-55.bpo-31783.lgLo69.rst diff --git a/Lib/concurrent/futures/thread.py b/Lib/concurrent/futures/thread.py index d84b3aa..b89f8f2 100644 --- a/Lib/concurrent/futures/thread.py +++ b/Lib/concurrent/futures/thread.py @@ -29,10 +29,14 @@ import os _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) @@ -156,7 +160,7 @@ class ThreadPoolExecutor(_base.Executor): self._initargs = initargs def submit(self, fn, /, *args, **kwargs): - with self._shutdown_lock: + with self._shutdown_lock, _global_shutdown_lock: if self._broken: raise BrokenThreadPool(self._broken) 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 0000000..a261e59 --- /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 -- cgit v0.12