From 1bfddf81e02177780a2525c8638b6081c273a336 Mon Sep 17 00:00:00 2001
From: James Addison <55152140+jayaddison@users.noreply.github.com>
Date: Fri, 8 Mar 2024 10:16:31 +0000
Subject: [PATCH] [CI/CD] implement readiness check before yielding
 local-http(s) test servers (#12050)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 CHANGES.rst    |  3 +++
 tests/utils.py | 10 ++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index d39895a9f..8de0fd00e 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -90,6 +90,9 @@ Bugs fixed
   Patch by Bénédikt Tran.
 * #12008: Fix case-sensitive lookup of ``std:label`` names in intersphinx inventory.
   Patch by Michael Goerz.
+* #12038: Resolve ``linkcheck`` unit test timeouts on Windows by adding a readiness
+  check to the test HTTP(S) server setup code.
+  Patch by James Addison.
 
 Testing
 -------
diff --git a/tests/utils.py b/tests/utils.py
index 32636b793..c82c449db 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,6 +1,7 @@
 import contextlib
 import http.server
 import pathlib
+import socket
 import threading
 from ssl import PROTOCOL_TLS_SERVER, SSLContext
 
@@ -15,11 +16,15 @@ CERT_FILE = str(TESTS_ROOT / "certs" / "cert.pem")
 # File lock for tests
 LOCK_PATH = str(TESTS_ROOT / 'test-server.lock')
 
+HOST_NAME = "localhost"
+HOST_PORT = 7777
+ADDRESS = (HOST_NAME, HOST_PORT)
+
 
 class HttpServerThread(threading.Thread):
     def __init__(self, handler, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self.server = http.server.ThreadingHTTPServer(("localhost", 7777), handler)
+        self.server = http.server.ThreadingHTTPServer(ADDRESS, handler)
 
     def run(self):
         self.server.serve_forever(poll_interval=0.001)
@@ -45,7 +50,8 @@ def create_server(thread_class):
             server_thread = thread_class(handler, daemon=True)
             server_thread.start()
             try:
-                yield server_thread
+                socket.create_connection(ADDRESS, timeout=0.5).close()  # Attempt connection.
+                yield server_thread  # Connection has been confirmed possible; proceed.
             finally:
                 server_thread.terminate()
     return contextlib.contextmanager(server)