[coyotos-dev] Voluntary Pageout

[Jonathan S. Shapiro]

On Sat, 2006-01-14 at 17:50 +0600, Constantine Plotnikov wrote:
> Described variant of media player is possible, but media
> players usually do not work this way precisely for the
> specified reason. So the media player use case does not
> justify this functionality. While other applications might
> need such functionality, I could not conceive such application
> right now. ...

I'm afraid that there has been confusion.

Internally, more and more implementations of libc (including hurd's)
attempt to implement I/O via memory mapping. They may map a moving
window on the file, but they do use mapping. In EROS/Coyotos, *all* file
I/O is ultimately handled by mapping *somewhere*.

So: another way to look at this is that it is a mechanism that can be
used inside stdio so that the read() or write() routines can indicate
that the current stream position has passed a given frame and keeping
the frame in memory is no longer a priority.