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Apple Freezes Snow Leopard APIs
DJRumpy writes in to alert us that Apple's new OS, Snow Leopard, is apparently nearing completion. "Apple this past weekend distributed a new beta of Mac OS X 10.6 Snow Leopard that altered the programming methods used to optimize code for multi-core Macs, telling developers they were the last programming-oriented changes planned ahead of the software's release. ...`Apple is said to have informed recipients of Mac OS X 10.6 Snow Leopard build 10A354 that it has simplified the`... APIs for working with Grand Central, a new architecture that makes it easier for developers to take advantage of Macs with multiple processing cores. This technology works by breaking complex tasks into smaller blocks, which are then`... dispatched efficiently to a Mac's available cores for faster processing."
what is the status of 10.6 on the PowerPC G5?
Spread your tiny wings and fly away,
And take the snow back with you
Where it came from on that day.
The one I love forever is untrue,
And if I could you know that I would
Fly away with you.
In a world of good and bad, light and dark, black and white, it remains very hopeful that Apple still sees itself as a beacon of purity. It pushes them to do good things to reinforce their own self-image.
I can't wait to try this latest OS!
Perhaps the editor doesn't know how to edit?
Oh wait, kdawson, never mind.
Why... is there... there so much... punctionations in the summary?
Because the summary is directly quoting the article and using ellipses to indicate that certain party of the quotation have been omitted. Usually there would be a space on either side of the ellipsis when this was done, but this is /. so I'll let this one slide.
Because it's a qoute. You see there are rules to any language and one of them in the English language is regarding quoting. When you quote a source the text written must be matching every word of the source. When the quote contains unnecessary text to the topic at hand you cut out that part and replace it with three periods. This indicates that there's a piece missing from the original quote, in case e.g. someone is questioning the quote at hand. So you see quoting is not interpreting, and must be, at all times, matching every word of the source.
Turn to side B for the next lesson.
I am the lawn!
The problem is shared-memory, not multi-processor or core itself. Graphics card have dedicated memory or reserve a chunk of the main memory.
It is true, because they privilege immutable data structures which are safe to access concurrently.
Only partly true. Even in pure functional languages like Haskell, the functional-programming dream of automatic parallelization is nowhere near here yet; in theory the compiler could just run a bunch of thunks of code in parallel, or speculatively, or whatever it wants, but in practice the overhead of figuring out which are worth splitting up has doomed all the efforts so far. It does make some kinds of programmer-specific parallelism easier; probably the most interesting experiments in that direction, IMO, is Clojure's concurrency primitives (Clojure's a Lisp-derived language with immutable data types, targeting the JVM).
Lisp, FWIW, doesn't necessarily privilege immutable data structures, and isn't even necessarily used in a functional-programming style; "Lisp" without qualifiers often means Common Lisp, in which it's very common to use mutable data structures and imperative code.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
I know it was partially true, I should remember not to be too lazy when posting on /. :).
Note that I was not talking about automatic parallelization which is indeed possible only with pure languages (and ghc is experimenting on it); but simply about the fact that is is easier to parallelize an application with immutable data structures since you need to care a lot less about synchronization. For instance, the Erlang actors model (also in other languages like Scala on the JVM) still requires the developer to define the tasks to be parallelized, yet immutable data structures make the developer's life a lot easier with respect to concurrent access and usually provide better performance.
My "It is true" was referring to "functional languages" which do usually privilege immutable data structures, not to Haskell or Lisp specifically (which as you said has many variants with mutable structures focused libraries). As you said, Clojure is itself a Lisp-1 and it does privilege immutable data structures and secure concurrent access with Refs/STM or agents. What is more interesting in the Clojure model (compared to Scala's, since they are often compared even though their differences, as functional languages and Java challengers on the JVM) is that it doesn't allow unsafe practices (all must be immutable except in variables local to a thread, etc).
Interesting times on the JVM indeed.
Yeah that's fair; I kind of quickly read your post (despite it being only one sentence; hey this is Slashdot!) so mistook it for the generic "FP means you get parallelization for free!" pipe dream. :)
Yeah, I agree that even if the programmer has to specify parallelism, having immutable data structures makes a lot of things easier to think about. The main trend that still seems to be in the process of being shaken out is to what extent STM will be the magic bullet some people are proposing it to be, and to what extent it can be "good enough" as a concurrency model even in non-functional languages (e.g. a lot of people are pushing STM in C/C++).
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Not really, PCs had disk drives for many more years. It was only when DVD writers became standards did it stop appearing in models.
Also, what other PC manufacturers even use PPC?
Change is certain; progress is not obligatory.
No ellipse is not a change to the text but a deletion from the text.
Alright guys, I know the advantages (and challenges) of multi-threading. With almost all new processors coming with > 1 core, I can tell there's now a huge desire to start making apps that can take advantage of all cores. But my question is why? One thing I love about my quad-core Q6600 is the fact that I can be doing so many things at once. I can be streaming HD video to my TV while simultaneously playing DOOM, for example. However, when I fire up a multithreaded app that takes all 4 of my cores and I start doing something heavy, like video encoding for example, everything tends to slow down like it did back when I only had one core to play with. Yeah, my encoding gets done a lot faster, but honestly I'd rather it take longer than make my computer difficult to use for any period of time...
I realize I can throttle the video encoding to a single core, but I'm just using that as an example... if all apps start using all cores, aren't we right back where we started, just going a little faster? I love being able to do so much at once...
I always read it as "Slow Leopard"
I'm one of the seed testers, and even posting anonymously, I am concerned not to violate Apple's NDA. So, I'll put it like this: I have 2 PPC machines and an Intel machine. I have only been able to get the SL builds to work on the Intel machine due, I'm pretty sure, to no fault of my own.
I'm by no means a multiprocessing expert, but I suspect the problem with your approach is in the overhead. Remember that the hardest part of multiprocessing, as far as the computer is concerned, is making sure that all the right bit of code get run in time to provide their information to the other bits of code that need it. The current model of multi-CPU code (as I understand it) is to have the programmer mark the pieces that are capable of running independently (either because they don't require outside information, or they never run at the same time as other pieces that need the information they access/provide), and tells the program when to spin off these modules as separate threads and where it will have to wait for them to return information.
What you're talking about would require the program to break out small chunks of itself, more or less as if sees fit, whenever it sees an opportunity to save some time by running parallel. This first requires the program to have some level of analytical capability for it's own code (Let's say we have two if statements one right after the other, can they be run concurrently? or does the result of the first influence the second? What about two function calls in a row?). The program will have to erect mutex locks around each piece of data it uses too, just to be sure that it doesn't cause dead locks if it misjudges whether two particular pieces of code can in fact run simultaneously.
It also seems to me (again I'm not an expert), that you'd spend a lot of time moving data between CPUs. As I understand it, one of the things you want to avoid in parallel programing is having a thread have to "move" to a different CPU. This is because all of the data for the thread has to be moved from the cache of the first CPU to the cache of the second. A relatively time consuming task. Multicore CPUs share level 2 cache I think, which might alleviate this, but the stuff in level 1 still has to be moved around, and if the move is off die, to another CPU entirely, then it doesn't help. In your solution I see a lot of these moves being forced. I also see a lot of "Chunk A and Chunk B provided data to Chunk C. Chunk A ran on CPU1, Chunk B on CPU2, and Chunk C has to run on CPU3, so it has to get the data out of the cache of the other two CPUS".
Remember that data access isn't a flat speed. l1 is faster than l2 which is much faster than RAM, which is MUCH faster than I/O buses. Anytime data has to pass through RAM to get to a CPU you lose time. With lots of little chunks running around getting processed, the chances of having to move data between CPUs goes up a lot. I think you'd lose more time on that then you gain by letting the bits all run on the same CPU.
I don't need a million points of light, just two points of multi-mode fiber and a 10 Gig-E router.
The Rewritable CD drive is not what killed off the floppy. The USB stick did.
Unfortunately that's not the issue at hand. You're referring to the video card using system RAM for it's own, but the issue they're talking about (which only occurs in the 32-bit world, not 64-bit, due to the MMU) is that to address the memory on the video card, it has to be put into the same 32-bit addressable block as the RAM, which cuts into being able to use it all, rather than using it physically. At least, that's how I understand it works.
That is, until some clever writer begins including square-bracketed ellipses in his or her text \[. . .\].
We just need escape codes :)
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
The same thing that happened to audio cds is going to happen to dvd. They will become obsolete as long as bandwidth keeps increasing.
A lot of people still can't get more than 0.05 Mbps dial-up. What, apart from a government-sponsored program analogous to rural electrification (started 1936 in the United States), is going to increase bandwidth to bufftuck nowhere?
From what I've read, they are cleaning up the code and optimizing it for the Intel platform. Supposedly it will take up less hard drive space and memory, but I'll believe that when I see it. Even if they fail, I'm glad they attempted this cleanup, even if it just inspires Microsoft to do some similar scrubbing with Windows 8. It's about time someone stopped and said, "Hey, instead of shiny feature 837, can we make sure that our web browser isn't leaking memory like a paper boat?"
It's not really for your mom - it's so she doesn't call you as often.
I'm usually a pretty big Mac fan-boy but I just can't seem to get excited about this one. Hell, I'm even thinking (seriously) about ditching my iPhone and getting a Palm Pre. sigh...how the world is changing. Has Apple lost it's Mojo?
I had the same thought. Apple is getting too greedy with their hardware prices, and they continue to screw customers over with their overpriced parts for repair. Plus, the computer world is changing, and they don't seem to understand what's happening.
Try remotely controlling a Mac with VNC over a cellular broadband connection. It's like sucking a watermelon through a straw. Try creating a virtual network of virtual machines for testing before deployment, which is illegal under Apple's TOS except for their server software. You'll be dragging your toaster into the bathtub by the end of the day.
Netbooks are evidence that people want computers for convenient access to information, usually located on the internet, and to have something to sync their iPod to. I'm not sure how much longer Apple can charge twice what their competitors are charging and get away with it. And they still have no chance of entering the enterprise market with their hardware costs and licensing restrictions.
I'm due for a laptop upgrade, and given the choice of a Dell Precision, RGBLED screen, and a dock that supports legacy ports and dual 30" displays, or a slower MacBook Pro with a crappier display for the same price, they're really making the decision for me. I'll continue recommending Macs for friends and family that may call me with technical questions, but if Windows 7 offers the same kind of robustness for half the price, what's the point?
Your mom will upgrade when new software requires Snow Leopard. Mac developers are pretty quick to adopt new APIs since they are usually making things really easy to do compared to the previous OS(such as Core Animation, Core Audio/Video etc.)
My impression of most Apple users is that they want not to use Microsoft products and do hide inside an elitist little club where there is no need for most of them to be concerned about technical issues. That's fine if that is what they want but those same people should not try to argue with people who do know what they are talking about when it comes to OSes - at least, in my case, when it comes to UNIX, Linux or Windows.
Most Apple people I know are very knowledgeable about other operating systems and make informed choices to use Macs. What does drive us nuts are those who criticize our choices but also freely admit...
I don't use Apple.
and
I know nothing about OSX.
No you're thinking of the Zune.
The MacBook Air is very popular, even though it costs a lot. People pay extra for "cool, sexy" Mac products (those are Microsoft's words used in its advertising about how cheap low end generic PCs are).
Actually I'm surprised by how many starving student types I see with an Air. I decided against buying one (which would have come in handy while traveling), but apparently the cool kids buy what they like, not what they "can afford."
They also buy expensive skinny jeans and $400 iPod touches and other stuff that Microsoft billionaires don't seem to think that they will. Of course, there are people who like to "save money," who go out and buy $700 PCs and then spend thousands of dollars putting GPU cards in them every six months to play the latest PC game.
And then there are those guys who saved money buying the Xbox 360 because it was so much cheaper than the PS3, except that it was only cheaper because it left off a lot of things like wireless and a hard drive. Plus they got a great deal on HD-DVD! And they ended up saving 80% on the Zune after it tanked and Microsoft dumped the extras on the market in a fire sale.
Microsoft is all about saving money! Except for the whole thing about Vista costing more than XP, and introducing a whole bunch of new licensing levels to force generic PC users to pay for features through software upgrades that "unlock" features for hundreds of dollars.
But yeah, your joke about there being two Zunes was funny stuff man, we should get together and play Halo in your mom's basement.