ARROW-15741: [Doc][Format] Clarify thread-safety of C stream interface

pitrou · pitrou · commit b956ba51ea11 · 2022-03-16T17:49:33.000+01:00
Closes apache#12647 from pitrou/ARROW-15741-stream-interface-thread-safety Authored-by: Antoine Pitrou <antoine@python.org> Signed-off-by: Antoine Pitrou <antoine@python.org>
diff --git a/docs/source/format/CStreamInterface.rst b/docs/source/format/CStreamInterface.rst
@@ -154,6 +154,12 @@ Stream lifetime
 Lifetime of the C stream is managed using a release callback with similar
 usage as in the :ref:`C data interface <c-data-interface-released>`.
 
+Thread safety
+-------------
+
+The stream source is not assumed to be thread-safe.  Consumers wanting to
+call ``get_next`` from several threads should ensure those calls are
+serialized.
 
 C consumer example
 ==================
