Issue #12364: Fix a hang in concurrent.futures.ProcessPoolExecutor.
diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py
index 8082940..d3bbe2c 100644
--- a/Lib/concurrent/futures/process.py
+++ b/Lib/concurrent/futures/process.py
@@ -213,9 +213,7 @@
work_item.future.set_exception(result_item.exception)
else:
work_item.future.set_result(result_item.result)
- continue
- # If we come here, we either got a timeout or were explicitly woken up.
- # In either case, check whether we should start shutting down.
+ # Check whether we should start shutting down.
executor = executor_reference()
# No more work items can be added if:
# - The interpreter is shutting down OR
@@ -234,9 +232,6 @@
p.join()
call_queue.close()
return
- else:
- # Start shutting down by telling a process it can exit.
- shutdown_one_process()
del executor
_system_limits_checked = False
diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py
index 6cc57f8..372da27 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 9212f9e..8e95abb 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -97,6 +97,10 @@
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.