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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?"
OSes like BeOS and Zeta are ahead of their time. With 8 core cpus coming out soon it just makes since with this technology... no programming tricks are needed.
||| I still can't believe Parkay's not butter.
Microsoft's plan is for us to keep adding CPU cores in the hope that at least one of them won't be deadlocked at any given moment in time.
No sig today...
Given that most machines are already starting to come default with 2 cores, and you can fit 8 cores (2 CPUs) in a nice desktop package, it's pretty clear that it's going to be a requirement.
It's not entirely the operating system's fault. The biggest advance of BeOS wasn't necessarily just that the kernel was designed to multithread nicely, Be also did their best to force you to write multithreaded code when you wrote a Be application.
I suspect that the first thing that's going to become clearly a performance bottleneck is the applications. And that's not going to be fun, because there's a lot of applications out there and you can't just magically recompile them with threads turned on and see much difference. You need to synchronize the data structures for multiple threads touching them at the same time and split things up so that you can actually keep a decent number of cores busy. This is not trivial when you are talking about an app that somebody wrote single threaded in the mid 90s without any notion that threads might be useful later.
Gentoo Sucks
BeOS was like JFK.
The both got gunned down before we could possibly see any downsides to them.
There were a few architectural decisions in BeOS that I felt would have resulted in great amounts of pain and suffering 10 years later.
Gentoo Sucks
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.
My blog
I believe that's covered by "There were a few architectural decisions in BeOS that I felt would have resulted in great amounts of pain and suffering 10 years later."
Rewriting things from the ground up, without acceptable justification, has never been an effective strategy.
Gentoo Sucks
[BSOD]
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Table-ized A.I.
128MB? In the mid 80s? Maybe you mean 4Mb :-)
X is being fixed, thankfully (finally). There are a lot of interesting projects, including but not limited to Xegl. Xegl, is the long term goal of the X server and pretty much reduces the X server to a tiny part of the system, basically mediating the input devices, rotation and display management and TCP/over-the-wire GL, if I understand correctly, by using the Embedded GL specifications.
Hey, I'm all for Amiga's but in the mid Eighties, if you had 128MB of ram and was downloading a file online, you must have been from the future.
What the heck are you talking about?
Just to be a little more correct here, I'm no hardware engineer but will try to be far more accurate.
The Amiga had a great messaging system in it's OS, you could easily pass messages to other windows and programs in intuition. Further, you had all that ARexx stuff, and you could script programs to interact very easily with it. Basically, every program could listen on it's own ARexx socket for commands from other programs. Of course, there was the poor (read, no) memory protection which made things very unstable if you did not know what you were doing. Despite all this cool stuff, the OS was actually the weakest link. It was rushed. I remember reading specs on the original intended, but non-implemented file system, and it was about as robust as a single user file system could possibly get.
You also had preemptive multitasking (not true co-operative) and a fantastic unified memory architecture with a very fast blitter. Another nice thing was
that the kernel was contained on ROM so that it booted quicker then any other platform of it's day, and still faster then most this day. And all those chips played nice
and were synced to an internal clock that ran on NTSC (or PAL) timings. This, of course, meant that interrupts worked seamlessly, and the chipset was handily compatible with video signals from television equipment. That last thing turned into an incredible boon for the entire film and television industry.
The strength of the Amiga was it's bus and it's architecture. They absolutely nailed so many things in it's design, it really was a thing of beauty.
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.
Vista, George W. Bush, elected because of his name, even though the prior iteration wasn't especially respected or well-liked. Introduced instability and performance issues, all in the name of "security". Many of the corporate interests who promoted him early on are having second thoughts.