Many ARM-based chips include the "Jazelle DBX" (Direct Bytecode eXecution) hardware CPU extension, which lets "95% of [JVM] bytecode" be executed directly by the CPU -- without need for recompilation to 'native' ARM/Thumb instructions. (See http://en.wikipedia.org/wiki/Jazelle )
However, unlike most of the ARM universe which is fairly open, Jazelle DBX's specs, implementation, and operating details are apparently a closely held secret, shared by ARM only with select JVM implementors. I'll be interesting to see if ARM decides to help out the OpenJDK people. Googling around, it looks like so far the answer has been "No."
That is a GREAT question, and the full answer is complicated and partially proprietary. But basically, you've touched on the problem of indirect control flow, which exists in C (call through a function pointer), C++ (virtual function calls), and in Java,.NET, ObjC, etc.
The general approach is that at each indirect call site, you "solve for" what the actual targets of the call could possibly be, and take it from there. The specific example you gave is actually trivially solved, since there's only one possible answer in the program; in large scale applications it is what we call "hard." And yes, in some cases we (necessarily) lose the trail; see "halting problem" as noted. But we do a remarkably good job on most real world application code.
I've been working with this team on this static binary analysis business for eight or nine years, and we still haven't run out of interesting problems to work on, and this is definitely one of them.
Nevertheless, White Flame, you should be proud. The SWEET16 implemention is pretty damn tight. If you can even squeeze out one byte, or one cycle, from a Wozterpiece like that, I say Congratulations, and Well done.
I gave a couple of these for the holidays this year thinking that this would be a great way for family to share pictures but we had an unbelievably difficult time getting them to share what we wanted when we wanted.
HTTP-NG ( http://www.w3.org/Protocols/HTTP-NG/ ) was researched, designed, and even, yes, implemented to solve the same problems that Google's "new" SPDY is attacking -- in 1999, ten years ago.
The good news is that SPDY seems to build on the SMUX ( http://www.w3.org/TR/WD-mux ) and MUX protocols that were designed as part of the HTTP-NG effort, so at least we're not reinventing the wheel. Now we have to decide what color to paint it.
Next up: immediate support in FireFox, WebKit, and Apache -- and deafening silence from IE and IIS.
For an Mac OS X volume (HFS, HFS+), I've had lots of luck with Data Rescue II ($99) for recovering from serious drive failures. For drives that are still operational but have become borked at the filesystem level, Disk Warrior does a great job of rebuilding a healthy new directory structure. I make it a point to always have a copy of Disk Warrior within 100 yards of my PowerBook.
Also, a couple of times I've had dying drives that work OK for a few minutes after a cold boot, and then they (heat up and) die. I've had good luck throwing the drive in the freezer (in a ziplock bag) for a day, then powering up it, recovering as much as I can until the drive chokes again, lather, rinse, repeat, until all recoverable data has been copies off to a good drive.
He WASN'T throttled to 48Kbps -- slower than a 56Kbps dialup modem.
He WAS throttled to 480Kbps, and was getting download speeds of about 50K (that's kiloBYTES) per second (per connection).
TFA:"Bringing up the Status window I noticed my download performance was a far cry from my 7 mbps speed, but rather a measly 0.48 mbps...:"
0.48Mbps = 480Kbps (kiloBITS/sec) = roughly about 48KBps (kiloBYTES/sec)
So the/. story summary makes things sound an order of magnitude worse than they are. But you know, what's just ONE order of magnitude of error between friends, right?
The Bell Centennial font, designed in 1976 for printing phonebooks, had "holes" designed into it for (excess) ink to flow into without compromising readability.
http://www.nicksherman.com/articles/bellCentennial.html
Interesting to see how the 'benefit' of holes has changed.
Well, it was pretty obvious then, at least to people in the business, especially considering that at least one earlier CDN patent (e.g., US Pat. 5,991,809, originally filed as provisional pat. 60/022,598, filed on July 25, 1996, by me) had already been granted and therefore made completely public in 1997. Clearway Technologies (my company) was already selling a commercial off-the-shelf CDN implementation system starting in September of 1996. Akamai's success has been substantial, and I feel it is truly well-deserved, but they were not the first to invent a CDN, nor the first to patent it, nor the first to bring it to commercialize it.
After reading TFA, consulting with several DSLR-owning friends, I just ordered a 6.3MP Fuji FinePix F30. One of the main selling points: ISO 3200 "at full resolution", and a remarkably low noise even at high ISOs. I considered the Canon SD800 IS, which provides image stabilization, but can't the the low-light tricks that the Fuji F30 can.
Fuji F30 + 1GB xD card = a hair under $300, and there's a $50 rebate, which you can use to buy a lens hood in the springtime when the rebate check arrives.
Anyway, ISO 3200 for under $300 ($250 if you believe in the rebate fairy) seemed like an excellent deal on a pretty good light-catcher.
wheel of reincarnation: [1968] Term used to refer to a well-known effect whereby function in a computing system family is migrated out to special-purpose peripheral hardware for speed, then the peripheral evolves toward more computing power as it does its job, then somebody notices that it is inefficient to support two asymmetrical processors in the architecture and folds the function back into the main CPU, at which point the cycle begins again.
Several iterations of this cycle have been observed in graphics-processor design, and at least one or two in communications and floating-point processors. [...]
It's astounding; time is fleeting. Marketing takes its toll.
Note the disappearance of the "under $500" Macintosh.
My read is that (1) Apple had shown the world that there were such things as "cheap Macs" and had gotten the word out 'enough', (2) Apple had already sold bare-bones-$499 systems to everyone who was lured in by the low box price but who was unwilling to pay a little more, (3) a majority of their 'Mac mini' customers were spending much more than $499 anyway, and I'm guessing that their research suggested that the customers were buying more on total-system-cost than on the just the cost of the bare box. But what do I know?
It looks cool, but I need to try one in person before I'd buy one. The main "two" buttons are described as "touch-sensitive" in the Tech Specs page, and I'm concerned that they might not actually have the positive "CLICK!" feel that real-button mice do, thereby messing with one of the most well-established tactile feedback loops in my life.
On the other hand, I can see programming the force sensitive side buttons to let add a "sudo" to the mouse action you're trying to perform. Can't drag that file to the Trash because you don't have permissions? No problem -- just squeeze the mouse really hard (hereby christened the "sudo squeeze"!) and try again!
When Mr. Lynn took the stage yesterday, he was introduced as speaking on a different topic, eliciting boos. But those turned to cheers when he asked, "Who wants to hear about Cisco?" As he got started, Mr. Lynn said, "What I just did means I'm about to get sued by Cisco and ISS. Not to put too fine a point on it, but bring it on."
Somehow, I suspect he's going to get what he asked for.
-Mark
Re:The Little LISPer teaches LISP this way
on
Astronomy Hacks
·
· Score: 1
Huh?
Last time I checked, LISP ran on lots of machines, not just Suns; even more for Scheme.
The Little LISPer teaches LISP this way
on
Astronomy Hacks
·
· Score: 1
The Little LISPer (MIT Press, 1980 & c.) uses a variation on Programmed Instruction to teach programming (in LISP) in a format that looks something like this. It's very effective, like the Stikky books.
And waaaay back in 1978, my 7th-grade English text book used this technique to teach grammar/syntax and how to diagram sentences. That stuff is still stuck in my head.
Apparently 99% of current 'programmed instruction' is done through computer-based tutorials, but I wish there were more books out there that used PI the way the Stikky ones do.
It really does feel like an 'information installer program' for the brain!
Slashdot Mirror
Many ARM-based chips include the "Jazelle DBX" (Direct Bytecode eXecution) hardware CPU extension, which lets "95% of [JVM] bytecode" be executed directly by the CPU -- without need for recompilation to 'native' ARM/Thumb instructions. (See http://en.wikipedia.org/wiki/Jazelle )
However, unlike most of the ARM universe which is fairly open, Jazelle DBX's specs, implementation, and operating details are apparently a closely held secret, shared by ARM only with select JVM implementors. I'll be interesting to see if ARM decides to help out the OpenJDK people. Googling around, it looks like so far the answer has been "No."
That is a GREAT question, and the full answer is complicated and partially proprietary. But basically, you've touched on the problem of indirect control flow, which exists in C (call through a function pointer), C++ (virtual function calls), and in Java, .NET, ObjC, etc.
The general approach is that at each indirect call site, you "solve for" what the actual targets of the call could possibly be, and take it from there. The specific example you gave is actually trivially solved, since there's only one possible answer in the program; in large scale applications it is what we call "hard." And yes, in some cases we (necessarily) lose the trail; see "halting problem" as noted. But we do a remarkably good job on most real world application code.
I've been working with this team on this static binary analysis business for eight or nine years, and we still haven't run out of interesting problems to work on, and this is definitely one of them.
Oops, I wasn't logged in. The above comment is from me, Mark Kriegsman, Director of Engineering at Veracode.
Nevertheless, White Flame, you should be proud. The SWEET16 implemention is pretty damn tight. If you can even squeeze out one byte, or one cycle, from a Wozterpiece like that, I say Congratulations, and Well done.
Thank goodness that's all solved now!
The good news is that SPDY seems to build on the SMUX ( http://www.w3.org/TR/WD-mux ) and MUX protocols that were designed as part of the HTTP-NG effort, so at least we're not reinventing the wheel. Now we have to decide what color to paint it.
Next up: immediate support in FireFox, WebKit, and Apache -- and deafening silence from IE and IIS.
Also, a couple of times I've had dying drives that work OK for a few minutes after a cold boot, and then they (heat up and) die. I've had good luck throwing the drive in the freezer (in a ziplock bag) for a day, then powering up it, recovering as much as I can until the drive chokes again, lather, rinse, repeat, until all recoverable data has been copies off to a good drive.
He WAS throttled to 480Kbps, and was getting download speeds of about 50K (that's kiloBYTES) per second (per connection).
TFA:"Bringing up the Status window I noticed my download performance was a far cry from my 7 mbps speed, but rather a measly 0.48 mbps...:"
0.48Mbps = 480Kbps (kiloBITS/sec) = roughly about 48KBps (kiloBYTES/sec)
So the /. story summary makes things sound an order of magnitude worse than they are. But you know, what's just ONE order of magnitude of error between friends, right?
The Bell Centennial font, designed in 1976 for printing phonebooks, had "holes" designed into it for (excess) ink to flow into without compromising readability. http://www.nicksherman.com/articles/bellCentennial.html Interesting to see how the 'benefit' of holes has changed.
It's not only +1 Informative, +1 Insightful, but also +1 Interesting.
Also, compared to a lawyer, it is +1 Useful and +1 Cheap, not to mention +1 Fits In A Backpack.
ls -slut shows most recently modified (used) files first.
ls -slut | head shows just the most recent ten.
OK, I'm interested. Where do you recommend picking up these cheap retired panels still generating 75% of their rated power? (And how cheap?)
Well, it was pretty obvious then, at least to people in the business, especially considering that at least one earlier CDN patent (e.g., US Pat. 5,991,809, originally filed as provisional pat. 60/022,598, filed on July 25, 1996 , by me) had already been granted and therefore made completely public in 1997. Clearway Technologies (my company) was already selling a commercial off-the-shelf CDN implementation system starting in September of 1996. Akamai's success has been substantial, and I feel it is truly well-deserved, but they were not the first to invent a CDN, nor the first to patent it, nor the first to bring it to commercialize it.
-Mark Kriegsman
Founder, Clearway Technologies
After reading TFA, consulting with several DSLR-owning friends, I just ordered a 6.3MP Fuji FinePix F30. One of the main selling points: ISO 3200 "at full resolution", and a remarkably low noise even at high ISOs. I considered the Canon SD800 IS, which provides image stabilization, but can't the the low-light tricks that the Fuji F30 can.
Fuji F30 + 1GB xD card = a hair under $300, and there's a $50 rebate, which you can use to buy a lens hood in the springtime when the rebate check arrives.
Anyway, ISO 3200 for under $300 ($250 if you believe in the rebate fairy) seemed like an excellent deal on a pretty good light-catcher.
-Mark
See the entry in the Hacker's Dictionary / Jargon File for "Wheel of reincarnation":
-Mark
1. Attach DDR dance pad to computer.
2. Remap key codes for debugger commands "Step In", "Step Over", "Step Out."
3. Actually step through code...
-Mark
It's astounding; time is fleeting. Marketing takes its toll.
Note the disappearance of the "under $500" Macintosh.
My read is that (1) Apple had shown the world that there were such things as "cheap Macs" and had gotten the word out 'enough', (2) Apple had already sold bare-bones-$499 systems to everyone who was lured in by the low box price but who was unwilling to pay a little more, (3) a majority of their 'Mac mini' customers were spending much more than $499 anyway, and I'm guessing that their research suggested that the customers were buying more on total-system-cost than on the just the cost of the bare box. But what do I know?
-Mark
See also Codase.com, another "Source Code Search Engine", which lets you search by method names, class names, variable names, free text, etc..
-Mark
If micropayments are for just a few cents, shouldn't transactions in the $10-$90 range be called millipayments?
-Mark
See various FAQs; "wb" is "welcome back", "ty" is "thank you".
-Mark
It looks cool, but I need to try one in person before I'd buy one. The main "two" buttons are described as "touch-sensitive" in the Tech Specs page, and I'm concerned that they might not actually have the positive "CLICK!" feel that real-button mice do, thereby messing with one of the most well-established tactile feedback loops in my life.
On the other hand, I can see programming the force sensitive side buttons to let add a "sudo" to the mouse action you're trying to perform. Can't drag that file to the Trash because you don't have permissions? No problem -- just squeeze the mouse really hard (hereby christened the "sudo squeeze"!) and try again!
-Mark
-Mark
Huh?
Last time I checked, LISP ran on lots of machines, not just Suns; even more for Scheme.
The Little LISPer (MIT Press, 1980 & c.) uses a variation on Programmed Instruction to teach programming (in LISP) in a format that looks something like this. It's very effective, like the Stikky books.
And waaaay back in 1978, my 7th-grade English text book used this technique to teach grammar/syntax and how to diagram sentences. That stuff is still stuck in my head.
Apparently 99% of current 'programmed instruction' is done through computer-based tutorials, but I wish there were more books out there that used PI the way the Stikky ones do.
It really does feel like an 'information installer program' for the brain!