Merge with 3.2 for #12364.

2 files changed, 6 insertions, 3 deletions

diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py
index 0575146b22..7f31ec2263 100644
--- a/Lib/concurrent/futures/process.py
+++ b/Lib/concurrent/futures/process.py
@@ -273,9 +273,6 @@ def _queue_management_worker(executor_reference,
                 if not pending_work_items:
                     shutdown_worker()
                     return
-                else:
-                    # Start shutting down by telling a process it can exit.
-                    call_queue.put_nowait(None)
             except Full:
                 # This is not a problem: we will eventually be woken up (in
                 # result_queue.get()) and be able to send a sentinel again.
diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py
index 7522a54acb..04ee246083 100644
--- a/Lib/test/test_concurrent_futures.py
+++ b/Lib/test/test_concurrent_futures.py
@@ -109,6 +109,12 @@ class ExecutorShutdownTest(unittest.TestCase):
         self.assertFalse(err)
         self.assertEqual(out.strip(), b"apple")
 
+    def test_hang_issue12364(self):
+        fs = [self.executor.submit(time.sleep, 0.1) for _ in range(50)]
+        self.executor.shutdown()
+        for f in fs:
+            f.result()
+
 
 class ThreadPoolShutdownTest(ThreadPoolMixin, ExecutorShutdownTest):
     def _prime_executor(self):