SO_KEEPALIVE flag on the underlying socket. When
this flag is set on a socket, the system will attempt to verify that the
remote socket endpoint is still present if a sufficiently long period of
time passes with no data being exchanged. If the system is unable to
verify the presence of the remote endpoint, it will automatically close
the connection.gSocketSetKeepalive(object, keepalive)objectGSocket.keepaliveG_SOCKET_PROTOCOL_TCP sockets.)
The exact time between pings is system- and protocol-dependent, but will
normally be at least two hours. Most commonly, you would set this flag
on a server socket if you want to allow clients to remain idle for long
periods of time, but also want to ensure that connections are eventually
garbage-collected if clients crash or become unreachable.
Since 2.22