[Python-checkins] bpo-35465: Document _UnixSelectorEventLoop.add_signal_handler. (GH-11145)

[Yury Selivanov]

https://github.com/python/cpython/commit/e3666fc8effb05b555121f4ab7388df59e21f8b4
commit: e3666fc8effb05b555121f4ab7388df59e21f8b4
branch: master
author: Hrvoje Nikšić <hniksic at gmail.com>
committer: Yury Selivanov <yury at magic.io>
date: 2018-12-18T16:31:29-05:00
summary:

bpo-35465: Document _UnixSelectorEventLoop.add_signal_handler. (GH-11145)

files:
M Doc/library/asyncio-eventloop.rst

diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
index da2339132a40..acf9477f723d 100644
--- a/Doc/library/asyncio-eventloop.rst
+++ b/Doc/library/asyncio-eventloop.rst
@@ -966,12 +966,20 @@ Unix signals
 
    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.