There was a very good article in Vector by Chris Burke which explained how mmf works. The overhead is very small, in fact if a file is opened, it should be already be memory mapped automatically in modern OS.
However mmf in J maps the entire file into RAM, iow the size of its viewport is the same as the whole file, so that beware of running out of RAM, especially if the file is larger than physical RAM or you map a lot of files. Пнд, 01 Авг 2011, Steven Taylor писал(а): > I was just playing around with mapped files > > (see: http://www.jsoftware.com/jwiki/Studio/Mapped%20Files#jmfUtilities). > > So, then I got to wondering what the overhead for having a mappped file open > was... and if there is a limit to how many you should have in a single J > Session (2, .., 5, .., 20, ..., ?). > > thanks, > -Steven > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm -- regards, ==================================================== GPG key 1024D/4434BAB3 2008-08-24 gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
