bpo-34037, asyncio: add BaseEventLoop.wait_executor_on_close (GH-13786)

Add BaseEventLoop.wait_executor_on_close attribute: true by default.

loop.close() now waits for the default executor to finish by default.
Set loop.wait_executor_on_close attribute to False to not wait for
the executor.

1 files changed, 3 insertions, 1 deletions

diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
index e002539..b1a7f88 100644
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -380,6 +380,8 @@ class Server(events.AbstractServer):
 class BaseEventLoop(events.AbstractEventLoop):
 
     def __init__(self):
+        # If true, close() waits for the default executor to finish
+        self.wait_executor_on_close = True
         self._timer_cancelled_count = 0
         self._closed = False
         self._stopping = False
@@ -635,7 +637,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         executor = self._default_executor
         if executor is not None:
             self._default_executor = None
-            executor.shutdown(wait=False)
+            executor.shutdown(wait=self.wait_executor_on_close)
 
     def is_closed(self):
         """Returns True if the event loop was closed."""