The scenario is that your Enlightenment (e17) desktop has locked up, and your keyboard and mouse appear to be non-responsive. However you do not want to reboot as you will lose all of your open windows.

It is possible to restart the Enlightenment engine without affecting the windows being currently displayed.

Either switch to a TTY (by pressing Ctrl+Alt+F1) or login remotely over ssh, and then execute:
env DISPLAY=:0 enlightenment_remote -restart

Your desktop should have now recovered its pre-locked up state.
(on most setups you can switch back to the desktop from your TTY by pressing Alt+F7)