waiting for arbitrary events SB-EXT:WAIT-FOR

waiting for arbitrary events SB-EXT:WAIT-FOR

  While using this to wait for other threads isn't good style,
  sometimes it is _much_ easier to just state the thing you're
  waiting for than build the synchronization to make it nice.

  And sometimes the event lives in the external world, in which case
  you really need to poll anyways:

    (wait-for (probe-file pathname))