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Intel Releases Threading Library Under GPL 2
littlefoo writes "Intel Software Dispatch have announced the availability of the Threading Building Blocks (TBB) template library under the GPL v2 with the run-time exception — so this previously commercial only package is now open for all the use, whether for open-source projects or commercial offerings (although they are explicitly encouraging open source use). The interface is more task-based then thread-based, but with a somewhat different view of things than, e.g. OpenMP.
From the Intel release: 'Intel® Threading Building Blocks (TBB) offers a rich and complete approach to expressing parallelism in a C++ program. It is a library that helps you leverage multi-core processor performance without having to be a threading expert. Threading Building Blocks is not just a threads-replacement library. It represents a higher-level, task-based parallelism that abstracts platform details and threading mechanism for performance and scalability.'"
I attended a seminar about this at GDC (Game Developers Conference) this year. It is really nifty stuff, automatically parallelizes things for you and helps take the load off of the OS scheduler. It is also trivial to implement in many cases, for instance there are parallel loops that execute things in parallel, all you have to do is write it like a normal loop but use a different keyword (ok so it is a wee bit more involved, but you get the idea). If I recall correctly it is basically a thread-pool that manages scheduling itself better than the OS because it knows ahead of time the needs of the code. Also you don't have to know the # of cores or anything as it handles that transparently. Also it isn't limited to Intel processors, I'm pretty sure at GDC it was actually being demoed on some sparc machines. If I had the time and/or a reason to use it I would definately investigate further.
If you are about to mod me down, keep in mind that this post was most likely sarcastic.
I looked at some of the tutorials yesterday, and I believe I'm going to dip my toes in this.
But. As much as I love C++ ( and I do ) the real weakness is the lack of usable closures/lambda. The parallel_for example requires you to pass a functor to execute on ranges, which is fine, it makes sense, but since you can't define the closure in the calling-scope in C++ you end up filling your namespace with one-off function objects.
This is not a critique of TBB, but rather of C++. In java I can make an anonymous subclass within function scope. In python and hell even javascript I can make anonymous functions to pass around. But in C++ I can't, and this means that my code will be ugly.
Not that this is new news. I use Boost.thread for threading right now, and most of my functors are defined privately in class scope ( which is, at the very least, not polluting my namespace ) but it's too bad that I don't have a more elegant option in C++.
That being said, Boost.lambda makes my brain hurt a little, so my complaints are really just a tempest in a teacup. If I were smarter and could really grok C++ I could probably use Boost.Lambda and this would be a non-issue.
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>There are 11 types of people in the world, those who know binaries and those who don't.
Obviously you are in the those who don't group.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
The AMD question was raised on their Forums, and there is no issues with TTB running on AMD CPUs.
And, if there was, well it's under the GPL now, and I'm sure someone would have added / corrected that mistake.
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Which is perfectly fine. I have a friend at Intel and based on what I've heard of the corporate culture, open ended licenses are a no-go. That doesn't mean they won't later release under GPL v3, just that they want their lawyers to have a chance to review any license they release under and don't want to be beholden to the unknown. Frankly I think that's a good thing. In theory GPLv4 could say: this can be used in closed source proprietary DRM schemes. and if they had the "or later" clause they would have to allow it.
-nB
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We've been supporting Linux, Windows and Mac OS X for x86, x86-64 and Itanium processors in the commercial product for a year. And, yes, those include Intel and AMD processors. The commercial product information only lists those.
;-) We're talking about what to do together to add SPARC support to - which shouldn't be too hard but will take some work.
The commercial product information quoted does not include some ports which were completed for the open source project only days before the open source release.
Preparing for open source, we were able to get G5 for Mac OS X as well as support for Solaris and FreeBSD (both x86 and x86-64) working before releasing on Tuesday. It was tight - but they made it. I wasn't sure until the week before what we would have - but the team got them working. I think it will be easier now that the project is started - and we can let other join in to help us.
I should also say we got a bunch more Linux distributions working for builds too. We have tested them enough to see no issues - but we haven't enough experience to call them supported on the product pages (commercial product). Please look for the latest ports on the open source project threadingbuildingblocks.org. We'll work with anyone who has processors/system expertise and needs any advice we can offer. Understandably, we don't have a lot of non-Intel hardware inside Intel to test upon and we are hoping others can help a bit with that.
For compilers - we have gcc, Intel, Microsoft and Apple (gcc in Xcode environment) compilers all working with the builds. It seems like we may have something to do for Sun's compilers and/or environment working - some Sun engineers are in touch and helping us double check this. No schedule - just working together - which I have faith will get results to put out in an updated open source copy in the not too distant future - non-binding wish - this is not a promise
The biggest issues from processor to processor is knowing how to implement a few key locks, and atomic operations, best in assembly language. Since we have support for processors with both weak and strong memory consistency models - we know TBB is up to the task.
TBB is very strongly tied to shared memory, and so a port to a Cell processor (or a GPU) would be a bit more challenging - but might be doable for the Cell. We've had only a few discussions/thoughts - no progress I know of figuring out a good approach there. That will almost certainly take someone with more Cell experience than we have at this time. I'm open to learning - but I'd need a teacher for sure.