Question

Optimal and Clock replacement algorithm

Asked by: identityless

I'm curious on how the clock replacement algorithm and Optimal replacement algorithm is implemented. I'm not looking for any code in any particular language, but pseduo-code would be fine. I can implement the LRU as I know the algorithm checks the frame for a particular page that has been in the frame longest; that can be determinisitc. However, for the optimal, it requires the knowledge of which pages will not be used the longest. How can I devise a pseduo-code that traces this?

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Asked On
2005-08-20 at 02:42:15ID21533836
Tags

replacement

,

clock

,

algorithm

Topic

Operating Systems Miscellaneous

Participating Experts
1
Points
125
Comments
4

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Answers

 

by: coderlenPosted on 2005-08-20 at 07:45:41ID: 14715757

This is a very unusual question! Are you writing an operating system? I've never seen anybody here at EE with your deep level of understanding, although surely they exist. I would think that a better TA (Topic Area) for you in EE would be "Programming".

Anyway, I found some stuff for you. I fear that you already know a lot of this, and that I might be insulting your intelligence with some of these links! But maybe you haven't seen some of them, and it will be helpful to you.

This link, perhaps the best one I found for your purposes, has some excellent links at the bottom of the page, many of which have pseudocode, and very technical explanations:
http://en.wikipedia.org/wiki/Page_replacement_algorithms

This link explains the Page Replacement Algorithms, with charts and pictures:
http://www.cs.sjsu.edu/faculty/khuri/cse99_b.pdf

This one explains FIFO with pseudocode:
http://www.sci.csuhayward.edu/~billard/cs4560/node15.html

This is a nice short article, with pseudocode:
http://www.cs.uiowa.edu/~jones/opsys/fall95/notes/0908.html

This one explains Page Replacement Algorithms, with emphasis on LRU, although there is no pseudocode:
http://www.cs.vu.nl/~ast/books/mos2/sample-4.pdf

 

by: coderlenPosted on 2006-01-28 at 19:54:17ID: 15815960

Venabili, thanks for doing cleanup on this one. I had forgotten about it.

20120131-EE-VQP-002

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