About non-blocking mode usage

[Liang Qin <lqin@xxxxxxxxxx>]

Does anyone has an example of how to use the non-blocking mode for libssh?
This include ssh_connect, ssh_userauth functions, ssh_channel functions
etc. these functions will return again in non-blocking mode, in the test
examples we see it just keep trying until we get ssh_ok, but this is not
efficient and will cause high cpu usage, I know we should use poll or
ssh_poll, but I did not find any docs or examples that shows how to use it.

Could anyone give me some example?
Thanks