bpo-35465: Document _UnixSelectorEventLoop.add_signal_handler. (GH-11145)
diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
index da23391..acf9477 100644
--- a/Doc/library/asyncio-eventloop.rst
+++ b/Doc/library/asyncio-eventloop.rst
@@ -966,12 +966,20 @@
Set *callback* as the handler for the *signum* signal.
+ The callback will be invoked by *loop*, along with other queued callbacks
+ and runnable coroutines of that event loop. Unlike signal handlers
+ registered using :func:`signal.signal`, a callback registered with this
+ function is allowed to interact with the event loop.
+
Raise :exc:`ValueError` if the signal number is invalid or uncatchable.
Raise :exc:`RuntimeError` if there is a problem setting up the handler.
Use :func:`functools.partial` :ref:`to pass keyword arguments
<asyncio-pass-keywords>` to *callback*.
+ Like :func:`signal.signal`, this function must be invoked in the main
+ thread.
+
.. method:: loop.remove_signal_handler(sig)
Remove the handler for the *sig* signal.