From f9231fa4af4fd13e61c3d74e9bad7915debd2a53 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@redhat.com>
Date: Tue, 15 Jan 2019 13:29:11 +0100
Subject: [PATCH] bpo-23846: Fix ProactorEventLoop._write_to_self()

asyncio.ProactorEventLoop now catchs and logs send errors when the
self-pipe is full: BaseProactorEventLoop._write_to_self() now catchs
and logs OSError exceptions, as done by
BaseSelectorEventLoop._write_to_self().
---
 Lib/asyncio/proactor_events.py                            | 8 +++++++-
 .../next/Library/2019-01-15-13-31-30.bpo-23846.LT_qL8.rst | 2 ++
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2019-01-15-13-31-30.bpo-23846.LT_qL8.rst

diff --git a/Lib/asyncio/proactor_events.py b/Lib/asyncio/proactor_events.py
index 3a1826e2c0d228..a849be1cc1479b 100644
--- a/Lib/asyncio/proactor_events.py
+++ b/Lib/asyncio/proactor_events.py
@@ -636,7 +636,13 @@ def _loop_self_reading(self, f=None):
             f.add_done_callback(self._loop_self_reading)
 
     def _write_to_self(self):
-        self._csock.send(b'\0')
+        try:
+            self._csock.send(b'\0')
+        except OSError:
+            if self._debug:
+                logger.debug("Fail to write a null byte into the "
+                             "self-pipe socket",
+                             exc_info=True)
 
     def _start_serving(self, protocol_factory, sock,
                        sslcontext=None, server=None, backlog=100,
diff --git a/Misc/NEWS.d/next/Library/2019-01-15-13-31-30.bpo-23846.LT_qL8.rst b/Misc/NEWS.d/next/Library/2019-01-15-13-31-30.bpo-23846.LT_qL8.rst
new file mode 100644
index 00000000000000..788f092df9c169
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-01-15-13-31-30.bpo-23846.LT_qL8.rst
@@ -0,0 +1,2 @@
+:class:`asyncio.ProactorEventLoop` now catchs and logs send errors when the
+self-pipe is full.