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Will Pervasive Multithreading Make a Comeback?
exigentsky writes "Having looked at BeOS technology, it is clear that, like NeXTSTEP, it was ahead of its time. Most remarkable to me is the incredible responsiveness of the whole OS. On relatively slow hardware, BeOS could run eight movies simultaneously while still being responsive in all of its GUI controls, and launching programs almost instantaneously. Today, more than ten years after BeOS's introduction, its legendary responsiveness is still unmatched. There is simply no other major OS that has pervasive multithreading from the lowest level up (requiring no programmer tricks). Is it likely, or at least possible, that future versions of Windows or OS X could become pervasively multithreaded without creating an entirely new OS?"
I still hate that BeOS went belly up. It was a great operating system but was crushed before it ever got very far. The hardware support was also amazing: it would run winmodems and other windows only hardware. I've never tried writing an operating system, but I hope some of the features from BeOS make it into linux/OSX. One interesting thing to note is Be was originally a mac alternative and was only later moved to x86.
Another cool operating system to check out is MenuetOS... it is written entirely in Assembly! Very fast boot times and the GUI and eevrything fits easily on a floppy!
Get a web developer
It isn't really the pervasive multithreading that does the job on responsiveness for BeOS, and nor does having the "two threads per window" thing (which I think is what the poster is referring to in terms of "pervasive multithreading) avoid "programmer's tricks" - in fact, you have to be just as careful as if you were developing with Windows, and span up a background thread. One issue for BeOS developers was the amount of hard thinking you had to do to perform simple tasks in a pervasively multi-threaded environment, when you're still having to deal with all the pitfalls of lock-based programming.
However, taking only a few cycles to spin up or kill a thread (rather than the 10,000 plus it takes Windows), or perform a context switch, is a significant help. (There used to be an interesting article benchmarking those things on the Be website, but I can't find it any more).
MS have also added some more interesting stuff to the scheduler in Vista, which helps with uninterrupted sound or movie playback, so at least some of that stuff is possible without a complete redesign.
A few years ago, on a Dual Celeron 366Mhz with 256MB of RAM, I went out of my way to attempt to crash it. I opened about 120 OpenGL demos with only minor decrease in performance. After inherriting that mainboard, processors and RAM from my uncle and then increasing it to 512MB, the same test ground both FreeBSD and Linux to a halt.
too true. The linux kernel beats the beos kernel in threading benchmarks, but the entire Be OS GUI stack (kernel, display, windowing, controls) were designed with multithreading in mind. X/KDE/GTK et al are relics based on 1986 era computing.
Recall that this was the effet of Intel's NSP (the ill-named "Native Signal Processing"), a real-time multui-thread scheduler inserted at the device-driver level of Windows. Combined with something called VDI (Video Direct Interface), which allowed applications to bypass the Microsoft GDI graphics layer in certain ways, this allowed multiple video, graphics, and audio streams, mixed and synchronized, on circa-1993 computers, something largely not even possible today. While NSP was intended primarily for media streams, its technology was broadly applicable to more responsive and vivid interfaces. The result was Microsoft's threat to cut off Intel from future Windows development and specifically to withhold 64-bit support from Itanium, to more publically support AMD (which they did, for a while), and to threaten any OEMs using the code with withdrawal of Microsoft software support. Much of this was detailed in the Microsoft anti-trust trial and the accompanying discovery documents. Under this pressure, Intel abandoned the software, transferring VDI to Microsoft (it formed the core of what was later called DirectX), and outright killing NSP. Andy Grove admitted to Fortune magazine "We caved." (http://cyber.law.harvard.edu/msdoj/transcript/sum maries2.html)
This is not to suggest that this was the best or only way to do this, or that others haven't done it and done it well. But despite the best efforts of Linus and friends, Windows remains the dominant desktop OS, and Windows continues to be built on a base of 1970s-era operating system principles. Microsoft has, and continues to, build substantial barriers to anyone trying to substantially modify the behaviour of Windows at the HAL/device layer. Whether VMWare and equivalent virtualization technologies are finally a camel's nose under the tent edge remains to be seen. But as long as Windows remains the dominant desktop OS, you can expect the desktop to lag 10-15 years (at best) behind the state of the art in OS, GUI, and real-time developments.
I'm a CS grad student at the University of North Carolina. I've never used BeOS, but I'm confident that responsiveness will increase, because the work I'm doing right now is attended to address this very issue.
The thing that makes multi threaded programming so difficult is concurrency control - it's extremely easy for programmers to screw up lock-based methods, deadlocking the entire system. The are newer methods of concurrency control that have been proposed, and the most promising method (in my opinion) is 'Software Transactional Memory' which makes it almost trivial to convert correct sequential code to code that is thread-safe. Currently, there are several 'High Performance Computing Languages' in development, and to my knowledge, they all include transactional memory.
The incredible difficulties involved in making chips faster are precipitating a shift to multicore machines. The widespread prevalence of these machines, coupled with newer concurrency control techniques will undoubtedly lead to an increase of responsiveness.
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This is good, I like this political stuff:
MS-DOS 1.0 was Herbert Hoover, aloof to the problems of the common man but friend of the engineer in all of us. Also discovered Transformers.
Mac OS 7-8-9, all Franklin Roosevelt, very competent, lead us through difficult times, but left a legacy of programs which have become quite a mixed bag.
Windows 3.1, Dwight Eisenhower, amiable enough, competent, but leaving historians (and many contemporaries) very wanting.
Windows 95 thru ME, Lyndon Johnson, one of the boys, very able at getting things done, but in the end a disaster, rightfully ceding his throne.
Windows NT, Richard Nixon, the archetypal back-room politician, ruthless, and ultimately brought down by little faults, but many believe he was a great president and did much to modernize the Republican Party.
Windows XP, Ronald Reagan, everybody who hates him never met him, he could charm anyone, the Great Communicator. Bought Iranian weapons for contras with drug money.
Mac OS X, Bill Clinton, cheerful and smart, if not the most productive. Known for his speeches.
Don't blame me, I voted for Baltar.