From: J. Nick Koston <nick@koston.org>
Date: Wed, 13 Dec 2023 00:29:21 +0000 (-1000)
Subject: gh-112989: asyncio: Reduce overhead to connect sockets with SelectorEventLoop (#112991)
X-Git-Tag: v3.13.0a3~411
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7e2d93f30b157e414924c32232bb748c8f66c828;p=thirdparty%2FPython%2Fcpython.git

gh-112989: asyncio: Reduce overhead to connect sockets with SelectorEventLoop (#112991)

_ensure_fd_no_transport had a KeyError in the success path
---

diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py
index d521b4e2e255..dcd5e0aa3450 100644
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
@@ -261,15 +261,11 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
             except (AttributeError, TypeError, ValueError):
                 # This code matches selectors._fileobj_to_fd function.
                 raise ValueError(f"Invalid file object: {fd!r}") from None
-        try:
-            transport = self._transports[fileno]
-        except KeyError:
-            pass
-        else:
-            if not transport.is_closing():
-                raise RuntimeError(
-                    f'File descriptor {fd!r} is used by transport '
-                    f'{transport!r}')
+        transport = self._transports.get(fileno)
+        if transport and not transport.is_closing():
+            raise RuntimeError(
+                f'File descriptor {fd!r} is used by transport '
+                f'{transport!r}')
 
     def _add_reader(self, fd, callback, *args):
         self._check_closed()
diff --git a/Misc/NEWS.d/next/Library/2023-12-12-05-48-17.gh-issue-112989.ZAa_eq.rst b/Misc/NEWS.d/next/Library/2023-12-12-05-48-17.gh-issue-112989.ZAa_eq.rst
new file mode 100644
index 000000000000..ceeab8cc7d6b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-12-12-05-48-17.gh-issue-112989.ZAa_eq.rst
@@ -0,0 +1 @@
+Reduce overhead to connect sockets with :mod:`asyncio` SelectorEventLoop.