9 Jan
2019
9 Jan
'19
8:13 p.m.
Warner Losh <imp(a)bsdimp.com> writes:
The name seems obvious because I've seen it for
the last 30 years. But I've
not seen it used elsewhere, nor have I seen it documented except in
relationship to Unix. [....]
It is also used by Erich Gamma's famous book "Design Pattern": The
Strategy Pattern. Is it somehow related to Unix (due to the reason that
the Unix device interface is designed in an object oriented fashion)?
Apart from that, U. Vahalia describes the strategy entry point in the
book "UNIX Internals: The new Frontiers" (ISBN 978-0131019089) as:
| d_strategy() - Common point for read and write requests to a block
| device. So named since the driver may use some strategy to reorder
| pending requests to optimize performance. Operates asynchronously - if
| the device is busy, the routine merely queues the request and returns.
| When the I/O completes, the interrupt handler will dequeue the next
| request and start the next I/O.
--
Christian Barthel