Merge with 3.2 for #12364.
diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py
index 0575146..7f31ec2 100644
--- a/Lib/concurrent/futures/process.py
+++ b/Lib/concurrent/futures/process.py
@@ -273,9 +273,6 @@
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 7522a54..04ee246 100644
--- a/Lib/test/test_concurrent_futures.py
+++ b/Lib/test/test_concurrent_futures.py
@@ -109,6 +109,12 @@
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):
diff --git a/Misc/NEWS b/Misc/NEWS
index 05664f6..fbc6f67 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -422,6 +422,10 @@
Library
-------
+- Issue #12364: Fix a hang in concurrent.futures.ProcessPoolExecutor.
+ The hang would occur when retrieving the result of a scheduled future after
+ the executor had been shut down.
+
- Issue #13502: threading: Fix a race condition in Event.wait() that made it
return False when the event was set and cleared right after.