[3.14] gh-144706: Warn against using synchronization primitives within signal handler...

gh-144706: Warn against using synchronization primitives within signal handlers (GH-144736)
(cherry picked from commit 945bf8ce1bf7ee3881752c2ecc129e35ab818477)

Co-authored-by: Robsdedude <dev@rouvenbauer.de>

diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
index 995f800528f376edd0e26f9d5599a3a226b3f9a9..41a08fb165e2b675b596ef5f170b5c30b27d4082 100644 (file)
--- a/Doc/library/signal.rst
+++ b/Doc/library/signal.rst
@@ -68,6 +68,11 @@ the synchronization primitives from the :mod:`threading` module instead.
 
 Besides, only the main thread of the main interpreter is allowed to set a new signal handler.
 
+.. warning::
+
+   Synchronization primitives such as :class:`threading.Lock` should not be used
+   within signal handlers.  Doing so can lead to unexpected deadlocks.
+
 
 Module contents
 ---------------