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Can you explain why abstraction is bad? Abstraction does _not_ mean your program will be slower. In fact, the opposite can happen, because the compiler has more

by rtpg 12y ago

Can you explain why abstraction is bad? Abstraction does _not_ mean your program will be slower. In fact, the opposite can happen, because the compiler has more context to work with, and can get rid of stuff. Haskell + stream fusion gives better results than well tuned C in some very typical situations http://research.microsoft.com/en-us/um/people/simonpj/papers/ndp/haskell-beats-C.pdf http://research.microsoft.com/en-us/um/people/simonpj/papers... Even just comparing C++/C, C++'s templating mechanisms mean that generic containers can be optimised on a per-type basis. Abstraction and overhead are not as tightly coupled as they used to be, and not introducing Heartbleed-style bugs is worth a lot in my opinion

nwmcsween 12y ago
Abstraction in my definition is hiding of complexity and it does just that.
saosebastiao 12y ago
The problem with abstraction is that in order to deterministically control performance, you have to break down all the walls of the abstraction anyway. If I'm not 100% confident that my compiler will optimize a vector op with SIMD, and I absolutely require SIMD performance, then I end up having to know the entire layer cake to be able to verify that it is doing exactly that. In most cases it isn't a bad thing at all. But a use case like a timekeeping daemon, where a single unexpected garbage collection pause could cause a world of problems, it most definitely is more pain than gain.
phkamp 12y ago
Abstractions are certainly not "bad", there are many abstractions in Ntimed, it's also pretty object-oriented if you care to take a look. This is more a matter of "the right language for the job" and for timing-critical systems programming running as root, that language is C. And there are plenty of common abstractions I would love see added to the C language: basic linked lists, byte-endianess and packing for struct members, validity intervals for integers and FP variables (like Ada!) Unfortunately my taste seems to be the direct opposite of ISO-C which have instead wasted time giving us another thread-API.

by rtpg 12y ago

nwmcsween 12y ago

Abstraction in my definition is hiding of complexity and it does just that.

saosebastiao 12y ago

The problem with abstraction is that in order to deterministically control performance, you have to break down all the walls of the abstraction anyway. If I'm not 100% confident that my compiler will optimize a vector op with SIMD, and I absolutely require SIMD performance, then I end up having to know the entire layer cake to be able to verify that it is doing exactly that. In most cases it isn't a bad thing at all. But a use case like a timekeeping daemon, where a single unexpected garbage collection pause could cause a world of problems, it most definitely is more pain than gain.

phkamp 12y ago

Abstractions are certainly not "bad", there are many abstractions in Ntimed, it's also pretty object-oriented if you care to take a look. This is more a matter of "the right language for the job" and for timing-critical systems programming running as root, that language is C. And there are plenty of common abstractions I would love see added to the C language: basic linked lists, byte-endianess and packing for struct members, validity intervals for integers and FP variables (like Ada!) Unfortunately my taste seems to be the direct opposite of ISO-C which have instead wasted time giving us another thread-API.