fixes

SkvProgrammer · SkvProgrammer · commit ad161da7c899 · 2025-11-23T11:22:17.000Z
diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst
@@ -57,6 +57,10 @@ The :mod:`functools` module defines the following functions:
    another thread makes an additional call before the initial call has been
    completed and cached.
 
+   Call-once behavior is not guaranteed: no locks are held during the function
+   call, so the same key may be computed multiple times concurrently.
+
+
    .. versionadded:: 3.9
 
 
