Apply hints when doing collective I/O
Before resolving #159 (closed), hints were applied by calling sion_ensure_free_space
on every task. This is currently not done anymore. One possible way to re-enable this would be to extend the protocol of the iterators in sion_internal_positioning.{c|h}
to return an enum
rather than bool
and use that to indicate a jump to a new block. (Or keep the boolean and return a true tagged union enum ??? { Remainder { length: i64 }, Jump { position: i64, length: i64 } }
.) Then on every jump to a different block either the sender or the collector can take action (apply hints).