introduce keepalive option and make common socket options function
Signed-off-by: Andy Green <andy.green@linaro.org>
diff --git a/README.coding b/README.coding
index b994f3a..7c9d631 100644
--- a/README.coding
+++ b/README.coding
@@ -162,3 +162,25 @@
callback, for clients there's a new callback just for this purpose
LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH.
+
+TCP Keepalive
+-------------
+
+It is possible for a connection which is not being used to send to die
+silently somewhere between the peer and the side not sending. In this case
+by default TCP will just not report anything and you will never get any more
+incoming data or sign the link is dead until you try to send.
+
+To deal with getting a notification of that situation, you can choose to
+enable TCP keepalives on all libwebsockets sockets, when you create the
+context.
+
+To enable keepalive, set the ka_time member of the context creation parameter
+struct to a nonzero value (in seconds) at context creation time. You should
+also fill ka_probes and ka_interval in that case.
+
+With keepalive enabled, the TCP layer will send control packets that should
+stimulate a response from the peer without affecting link traffic. If the
+response is not coming, the socket will announce an error at poll() forcing
+a close.
+