Posted by avsm
Thu, 26 Aug 2004 23:20:36 GMT
Sitting in the New York JFK United lounge (which incidentally, has free wifi). Spent a great week in Princeton with Sandy Fraser at Fraser Research - full coverage available in Dave "blogthief" Scott's blog.
Ordered a Cyclades TS-800 to act as serial console server for the Flirble and Recoil machine clusters. Hopefully this should cure the woes with remote management of x86 servers (why, oh why, can't they have something as cool as Sun LOM?)
Posted in usa, travel, recoil, princeton | no comments
Posted by avsm
Mon, 16 Aug 2004 20:04:18 GMT
Apparently rumours are flying around at Crypto 2004 that the popular cryptographic hash function SHA-1 has been partially cracked. A collision for SHA-0 was also announced at the conference. More details in Ed Felten's blog.
Posted in hacking | no comments
Posted by avsm
Sun, 15 Aug 2004 12:30:59 GMT
Although dynamically typed (so-called "scripting languages") such as
Python and PHP have been gaining popularity in recent years, statically typed languages which fail on type errors at compile-time as opposed to run-time (e.g. OCaml) are often overlooked. Static typing prevents a number of stupid errors from happening at some random point in a program's execution, but forces the programmer to go through greater effort to actually design the program. I stumbled across the excellent Lambda the Ultimate programming languages weblog which has two great, largely flame-free discussions about the relative merits of both approaches. Check out the threads here and here.
Posted in hacking | no comments
Posted by avsm
Fri, 13 Aug 2004 21:59:11 GMT
Nick pointed me out to an extremely impressive project demoed at SIGGRAPH this year. The algorithm brings two videos into spatio-temporal alignment in order to perform various transforms such as background subtraction, increasing dynamic range, or even nifty compositing effects. There's a really cool video with a voice-over that explains everything, and further information in their paper.
Posted in hacking | no comments
Posted by avsm
Fri, 13 Aug 2004 13:34:36 GMT
Just returned from an excellent trip to Los Angeles, where I checked out Anand and Jyothsna's brand new house in Camarillo. I picked a good weekend to show up, as the Kush Games company picnic was on that weekend, resulting in a great few hours of beach volleyball being played. Ahh, maybe California isn't so bad after all...
And on returning to Cambridge, I discover that the latest in-thing from the local crazy Canadian is improving grip strength by doing extreme pullups with some ridged climbing holds slung over a fire escape. Check out the exciting pictures of Alex Ho and myself in action below! There is hot competition between Kieran Mansley and myself, mainly because my hard-earnt benchpress-specialised pecs only get in the way for pullups!
Anand shoots it low, I take it high! |
3000 miles later, hanging out in Cambridge |
Alex hangs with zen-like calm |
Posted in sport, usa, travel, family | no comments
Posted by avsm
Sun, 08 Aug 2004 23:02:08 GMT
Thierry Deval has recently committed an impressive implementation of
malloc that uses mmap
instead of the older sbrk to allocate memory in OpenBSD.
The advantage of the new approach is that it allows all the neat randomization
features that have been added to OpenBSD recently to happen transparently in malloc
(so that you don't just get consecutive pages back as in most operating systems).
The downside is a slight slowdown, but in this age of insane CPUs, who cares?
It has had the side-effect of exposing a number of latent bugs in programs which
silently access memory locations larger than the area they malloced; I
fixed one
which had remained lurking in my gcc bounds checker (see gcc-local) for over a year, and
other bugs have cropped up in programs as important as newfs. Until someone
goes through the pain of porting the awesome Valgrind to
OpenBSD, being able to expose more bugs this way is pretty useful.
Posted in openbsd, hacking | no comments
Posted by avsm
Thu, 05 Aug 2004 11:30:00 GMT
I really love using MacOS X as a desktop machine; I've used
it since the early days on my G4 Powerbooks and it's nice to see it coming along in leaps and bounds.
Unfortunately, every time I try to hack apps on it, it seems like a big icky mess. I've mainly done QuickTime hacking, and the APIs seem to date back literally decades, with the main documentation consisting of irritatingly out-of-date sample code on the Apple website, of which some only compiles on MacOS 9.
A good point in case is their API to grab images from Firewire cameras, such as my iSight (for doing SpotCode detection). Flicking through Apple docs, one finds the Sequence Grabber API, but profiling on that turns out to do a large amount of data copying that makes meaningful real-time image detection really hard. Instead, the answers from the very helpful chaps at the QuickTime-API mailing list suggest accessing the video digitizer codec directly, and then mapping using custom OpenGL extensions to avoid copying to texture memory.
It's a neat solution, but impossible to see from the Apple documentation; luckily Daniel Heckenberg wrote the seeSaw example which does illustrate some of these concepts nicely, along with an informative paper on the subject. It's not all bad news on the MacOS X front of course - their UNIX support is really good, and looks set to continue to improve with Tiger! All I really need is a Cocoa/OCaml bridge to silence my complaints ...
Posted in hacking | no comments
Posted by avsm
Thu, 05 Aug 2004 11:23:04 GMT
Sitting in Heathrow Terminal 3
waiting to board a flight to Los Angeles... it's nice to see that the airport finally has
low-cost WiFi access (at least in Terminal 3). It would be have been great to have this when I was
flying pretty much every day with NetApp; it must be a great way
to milk money out of thousands of business travellers sitting around with nothing else to do for hours!
Posted in usa, travel | no comments
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