gh-145587: fix busy loop in multiprocessing.connection.wait on Windows

Lib/multiprocessing/connection.py

@@ -1085,6 +1085,14 @@ def wait(object_list, timeout=None):
 
         Returns list of those objects in object_list which are ready/readable.
         '''
+        if not object_list:
+            if timeout is None:
+                while True:
+                    time.sleep(1e6)
+            elif timeout > 0:
+                time.sleep(timeout)
+            return []
+
         if timeout is None:
             timeout = INFINITE
         elif timeout < 0:

Misc/NEWS.d/next/Library/2026-03-07-14-34-39.gh-issue-145587.flFQ5-.rst

@@ -0,0 +1 @@
+Resolved a performance regression in ``multiprocessing.connection.wait`` on Windows that caused infinite busy loops when called with no objects. The function now properly yields control to the OS to conserve CPU resources.