From 4b11d7118561a12322d3cfa76c5941690b241149 Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Mon, 29 Nov 2021 04:24:08 -0800 Subject: [PATCH] bpo-43498: Fix dictionary iteration error in _ExecutorManagerThread (GH-24868) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit (cherry picked from commit 7431448b817d3bf87f71661cf8f3d537807ab2e2) Co-authored-by: Jakub Kulík --- Lib/concurrent/futures/process.py | 2 +- .../next/Library/2021-04-20-14-14-16.bpo-43498.L_Hq-8.rst | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Library/2021-04-20-14-14-16.bpo-43498.L_Hq-8.rst diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py index 764719859f7c..6ee2ce626e45 100644 --- a/Lib/concurrent/futures/process.py +++ b/Lib/concurrent/futures/process.py @@ -373,7 +373,7 @@ class _ExecutorManagerThread(threading.Thread): assert not self.thread_wakeup._closed wakeup_reader = self.thread_wakeup._reader readers = [result_reader, wakeup_reader] - worker_sentinels = [p.sentinel for p in self.processes.values()] + worker_sentinels = [p.sentinel for p in list(self.processes.values())] ready = mp.connection.wait(readers + worker_sentinels) cause = None diff --git a/Misc/NEWS.d/next/Library/2021-04-20-14-14-16.bpo-43498.L_Hq-8.rst b/Misc/NEWS.d/next/Library/2021-04-20-14-14-16.bpo-43498.L_Hq-8.rst new file mode 100644 index 000000000000..4713d1427ccd --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-04-20-14-14-16.bpo-43498.L_Hq-8.rst @@ -0,0 +1,2 @@ +Avoid a possible *"RuntimeError: dictionary changed size during iteration"* +when adjusting the process count of :class:`ProcessPoolExecutor`. -- 2.47.3