This method will force a read-write cycle and returns if it's fully
done or not. It may be used to force data to be written before a
handle is deleted (when one can't wait for the data to be written
asynchronously).
This is handful to error the copier with ETIMEDOUT if there are no
reads or writes in the given amount of time.
Since copiers are usable to download data or handle network clients,
it's easy to set a timeout and disconnect, let's say UDP clients that
are gone.
These interfaces allows generic operations on objects that can store
or provide data, such as a file or a buffer.
With well defined interfaces and events we can create code such as
Efl.Io.Copier, that will link a source with a destination and
progressively copy data as they appear.
Gustavo Sverzut Barbieri
Stefan Schmidt
Daniel Kolesa