Thermal Noise

Paper by Rivest et al:

http://cg.scs.carleton.ca/~morin/teaching/5408/refs/gr93.pdf

And the mandatory sucky applet:

http://people.ksp.sk/~kuko/bak/index.html

Found this out while lifelessly grokking around boost:

http://www.boost.org/doc/libs/1_35_0/doc/html/intrusive/sg_set_multiset.html

Balanced Trees are better than unbalanced because of bounded worst-case O(log n) search time. And AVL is the simplest balanced tree. Red-Black is better than AVL because worst-case O(1) rebalancing during (Updated) insertions are guaranteed. But Scapegoats are even better because they gaurantee O(1) rebalancing AND don’t need the extra field for storing the color of the node. Strange that I have not even heard of a 1993 data structure that sounds practical enough.

For the past month or so, I’ve been trying to understand what appears to be a black art mostly because of lacking documentation - Python bytecode generation and peephole optimization. Some notes from the study for the benefit of IRC-mate ‘jstatm’ and anyone else living on similar planes of insanity.
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Netbeans users on Solaris and Linux, who hate, detest and despise the horrible looking default Java UI, ought to add this line to ~/.bash_profile

alias netbeans=’/opt/netbeans/bin/netbeans -laf com.sun.java.swing.plaf.gtk.GTKLookAndFeel’

Update: Netbeans 6.0 users should type “–laf” instead “-laf” (Two hyphens before ‘laf’ instead of one)

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Here is an example of how incredibly powerful DTrace can be. I had to solve a problem where a nice high-level overview of the code flow in a single threaded userland application would save me some pain the backside. Lo and Behold, Dtrace - The Universal Hammer for every nail.

Here is a simple visual call graph generator using 5 lines of DTrace combined with the outstanding Graphviz graphics library.

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For the last two weeks, I’ve spent every ounce of my spare time trying to finish “Beautiful Code”. There will be two kinds of people: Those who think its a pointless piece of non-sense and Those who find the book a religious experience . Sharing as they did, some of their most intense experiences of programming and profound insights into the art, were legendary modern day programmers who stand tall to inspire us all: Brian Kerninghan, Karl Fogel, John Bentley, Charles Petzold, Greg Kroah-Hartman, Simon Peyton Jones and Bryan Cantrill.

The two best chapters in the book were: Beautiful Debugging & A Spoonful of Sewage.

I am ordering a hard copy so that I can pray to the book everyday

Juergen Brendel who commented on my post, about the Global Interpreter Lock, wrote a open letter pleading Guido to consider removing the GIL. Guido gave a seasoned response on his blog today - Anyone willing to do the hard work is free to submit a patch for Py3K AND prove that it does not affect single threaded performance. A fair call on Guido’s part and very generous of him to respond to yet-another-rant-about-the-GIL.

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I had my DTrace article published in this month’s edition of Linux for You. It is a gentle introduction to the curious Unix programmer. I can’t reprint the article on the blog. But if you aren’t convinced about looking into DTrace yet, read on….

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While the rest of the world drooled over the iPhone, I got to play around with a SunSPOT today. W00t !

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I’d interviewed a few folks on Python lately as a favor for a friend. Without laboring into details, there is one question that seems to baffle most candidates consistently. The first time I had to ask this question was because I couldn’t think of anything else “sane” at that point in time - and since the reaction by the (otherwise smart) candidate gave rise to a vicious notion of a entertainment, I kept repeating the question to every single person I interviewed subsequently !

Question: If the expression (0.99 - 0.90 - 0.09) were to be evaluated by the cpython interpreter, what would be the result ?

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Computing is interesting because it is fraught with problems. The argument that those problems are not interesting because they are man-made, is fallacious because problems of living and day-to-day life aren’t created by god either and they are usually more pointless. But that is besides the subject, which is actually something that sounds mundane but is frighteningly complicated to implement: “How to validate an Email Address ?”

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I recently came across an interesting hack in the linux kernel called “kexec”. exec() loads a userland program by overwriting the address space of the process calling the syscall. kexec is supposed to do the same with the kernel. Replace the running copy of a kernel with a newly specificed kernel.

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Are you good at Dtrace ? You might have a job in hand ! Here is something that appeared in the Times of India supplement yesterday.

Its a pleasant surprise that DTrace is now a hot job skill in the Indian Market too ! Of course it helps to know the similar family of tools like CodeAnalyst, VTune, oprofile, valgrind, SystemTap, Perftools ….

Every conversation with geeks not working in Sun this week has been about ZFS and ZFS making it to Mac OS X - Leopard. I get thoroughly drilled on Sun’s financial strategy and how we plan to make money rather than being asked about instantaneous snapshots and self-healing capabilities of ZFS. Thats one of the disadvantages of working for a “Non-Profit Organization” (of which we are very proud, anyway)

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I attended Barcamp Bangalore today. Was there to rant (as usual) on OpenSolaris. Barcamp is supposed to be a Web 2.0 ish place and you find a lot of doods who talk about RoR, Agile, Xtreme Programming, Springs, JUnit and such. It is a world far far far removed from my own domain of Operating Systems where I am still confused about a few AMD instructions and libc bindings. Nevertheless, Web 2.0 is one of the areas where OpenSolaris can have a really strong presence. Companies like Joyent have proved just that. So that was my excuse to spend the weekend at BarCamp.

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Here is a list of posts I wrote on my official weblog about FOSS.IN/2006.
Day 1

Day 2

Day 3

It might well go down in history as the month that changed the World. Or atleast the part of the world that me and my fellow humans who get paid for creating strings of ones and zeroes are primarily concerned with.

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Funny mail archived on LWN that draws an analogy to the working of the infamous OOM on Linux.

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No one knows what exactly “Web 2.0″ is. But everybody seems to preparing for it. I am too energetic to be left behind !

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Another feather to the DTrace cap. DTrace has been ported to MacOS !!!

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Guido van Rossum explains the Philosophy, Process, Features and Timeline for Python 3

http://video.google.com/videoplay?docid=-6459339159268485356

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