Issue #8407: The signal handler writes the signal number as a single byte
instead of a nul byte into the wakeup file descriptor. So it is possible to
wait more than one signal and know which signals were raised.
diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst
index 14f06af..37f96ce 100644
--- a/Doc/whatsnew/3.3.rst
+++ b/Doc/whatsnew/3.3.rst
@@ -131,6 +131,10 @@
* :func:`~signal.sigpending`: examine pending functions ;
* :func:`~signal.sigwait`: wait a signal.
+* The signal handler writes the signal number as a single byte instead of
+ a nul byte into the wakeup file descriptor. So it is possible to wait more
+ than one signal and know which signals were raised.
+
Optimizations
=============