From 85bf7c3794cf268f1a016420fbe36f85374151f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 2 Dec 2024 13:52:53 +0100
Subject: [PATCH] Indicate that `Shelve.sync()` is not thread-safe.

---
 Doc/library/shelve.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Doc/library/shelve.rst b/Doc/library/shelve.rst
index 6e74a59b82b8ec..f6c346f8e031ff 100644
--- a/Doc/library/shelve.rst
+++ b/Doc/library/shelve.rst
@@ -78,6 +78,13 @@ Two additional methods are supported:
    dictionary on disk, if feasible.  This is called automatically when the shelf
    is closed with :meth:`close`.
 
+   .. warning::
+
+      During the call to :meth:`!sync`, the *writeback* attribute is set to
+      :const:`False` and other threads will stop updating the cache. As such,
+      this method is **not** thread-safe.
+
+
 .. method:: Shelf.close()
 
    Synchronize and close the persistent *dict* object.  Operations on a closed