gh-89977: Revert epoll GIL changes

Author: methane

Lib/test/test_epoll.py

@@ -238,16 +238,6 @@ def test_unregister_closed(self):
             ep.unregister(fd)
         self.assertEqual(cm.exception.errno, errno.EBADF)
 
-    def test_unregister_twice(self):
-        with select.epoll() as ep:
-            ep.register(self.serverSocket)
-            ep.unregister(self.serverSocket)
-            with self.assertRaises(OSError) as cm:
-                ep.unregister(self.serverSocket)
-            self.assertEqual(cm.exception.errno, errno.ENOENT)
-            ep.register(self.serverSocket)
-            ep.unregister(self.serverSocket)
-
     def test_close(self):
         open_file = open(__file__, "rb")
         self.addCleanup(open_file.close)

Misc/NEWS.d/next/Library/2026-09-23-09-21-25.gh-issue-89977.fmia18.rst

@@ -1,3 +1,3 @@
 Avoid releasing the GIL for :meth:`socket.socket.setblocking`,
-:meth:`socket.socket.getsockname`, :meth:`socket.socket.getpeername`,
-:func:`socket.gethostname`, and :meth:`select.epoll.unregister`.
+:meth:`socket.socket.getsockname`, :meth:`socket.socket.getpeername`, and
+:func:`socket.gethostname`.

Modules/selectmodule.c

@@ -1521,8 +1521,9 @@ pyepoll_internal_ctl(int epfd, int op, int fd, unsigned int events)
         /* In kernel versions before 2.6.9, the EPOLL_CTL_DEL
          * operation required a non-NULL pointer in event, even
          * though this argument is ignored. */
-        /* Removing a watch is normally quick, so keep the GIL. */
+        Py_BEGIN_ALLOW_THREADS
         result = epoll_ctl(epfd, op, fd, &ev);
+        Py_END_ALLOW_THREADS
         break;
     default:
         result = -1;