gh-151640: add NEWS entry

pedramkarimii · pedramkarimii · commit e66d2fb3e4b2 · 2026-06-27T13:17:23.000+03:30
diff --git a/Misc/NEWS.d/next/Library/2026-06-18-12-48-03.gh-issue-151640.rst b/Misc/NEWS.d/next/Library/2026-06-18-12-48-03.gh-issue-151640.rst
@@ -0,0 +1,3 @@
+Fix a data race in :class:`io.BytesIO` in free-threaded builds when
+whole-buffer reads or :meth:`~io.BytesIO.getvalue` share the internal buffer
+with concurrent writes.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+Fix a data race in :class:`io.BytesIO` in free-threaded builds when
	`2`	+whole-buffer reads or :meth:`~io.BytesIO.getvalue` share the internal buffer
	`3`	`+with concurrent writes.`