bpo-35017, socketserver: don't accept request after shutdown (GH-9952)

beledouxdenis · vstinner · commit 10cb3760e863 · 2018-10-26T15:46:17.000+02:00
Prior to this revision, after the shutdown of a `BaseServer`,
the server accepted a last single request
if it was sent between the server socket polling
and the polling timeout.

This can be problematic for instance for a server restart
for which you do not want to interrupt the service,
by not closing the listening socket during the restart.
One request failed because of this behavior.

Note that only one request failed,
following requests were not accepted, as expected.
diff --git a/Lib/socketserver.py b/Lib/socketserver.py
@@ -230,6 +230,9 @@ def serve_forever(self, poll_interval=0.5):
 
                 while not self.__shutdown_request:
                     ready = selector.select(poll_interval)
+                    # bpo-35017: shutdown() called during select(), exit immediately.
+                    if self.__shutdown_request:
+                        break
                     if ready:
                         self._handle_request_noblock()
 
diff --git a/Misc/NEWS.d/next/Library/2018-10-26-00-11-21.bpo-35017.6Ez4Cv.rst b/Misc/NEWS.d/next/Library/2018-10-26-00-11-21.bpo-35017.6Ez4Cv.rst
@@ -0,0 +1,3 @@
+:meth:`socketserver.BaseServer.serve_forever` now exits immediately if it's
+:meth:`~socketserver.BaseServer.shutdown` method is called while it is
+polling for new events.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+:meth:`socketserver.BaseServer.serve_forever` now exits immediately if it's
	`2`	+:meth:`~socketserver.BaseServer.shutdown` method is called while it is
	`3`	`+polling for new events.`