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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?"
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.
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.