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Using D to Create the World’s Fastest File System

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Re: Using D to Create the World’s Fastest File System

#101

Post by pjmlp »

jdright wrote: post #95
pjmlp wrote: post #89

Earlier quoted context omitted.

On what concerns video games, all major engines do use GC on gameplay code, including variations of C++ GCs.

emphasis on gameplay code . And even there, if you target 60fps (sure a minority of developers), then GC is a liability at best.

But that is exactly the point. One should not constrain productivity just based on hypothetical goals, web scale and such similar arguments.

Doing the next Fortnite, Crysis or ground breaking AR/VR/Ray Tracing? Sure, every ms/byte counts.

Doing a typical Flash like casual game, game prototypes at Ludum Dare, participating at IGF? Having a GC around isn't the biggest concern.

Re: Using D to Create the World’s Fastest File System

#102

Post by yvdriess »

chappar wrote: post #58
WalterBright wrote: post #26

Earlier quoted context omitted.

If I may be blunt, I could hardly believe SFINAE was a feature, and hated implementing it. But one thing I liked about C++ was the partial ordering scheme for template selection. I liked it so much D uses it for both templates and function overload selection (as opposed to the multi-level argument matching scheme C++ uses). Once I figured it out, I thought it was a beauty.

Do you mind giving an example for the specific use of "c++ partial ordering scheme for template selection"?

Essentially, it is the algorithm by which the C++ compiler selects what template specialization to use at your 'call' site. Function templates can be overloaded and essentially create an entire family of specializations. As a C++ programmer, you either modify+compile+run until you get your desired call/specialization; or you take the plunge once your start to heavily rely on meta-template magic and try to grok the ordering scheme defined by the standard.

Crucially, this is completely different from say the way function overload resolution happens in C++. Fun stuff happens in your brain when you try combining different types of selection/overloading (ever tried combining template and regular function overloading on a templated class method?).

Compare ADL (https://en.cppreference.com/w/cpp/language/adl), overload resolution (https://en.cppreference.com/w/cpp/language/overload_resoluti...) and function template overloading (https://en.cppreference.com/w/cpp/language/function_template...)

Re: Using D to Create the World’s Fastest File System

#103

Post by vram22 »

lispm wrote: post #82
vram22 wrote: post #79

Earlier quoted context omitted.

>ITA for Common Lisp. >A pattern I seem to observe is that if the program/framework/platform grows large and successful enough, the company gets acquired for its tech and everything gets rewritten in some more 'industry standard' language. I wonder if that happened for ITA's software after ITA was acquired by Google (for some hundreds of millions, IIRC). I read somewhere that Paul Graham's ViaWeb, which was written i…

Probably it's not that easy to replace Lisp for something else at Google, since it implements a relatively complex search engine core. Thus it's still used. I guess they WOULD be happy to replace it, since Lisp is otherwise not used much at Google, AFAIK. ITA/Google also developed another complex application using Lisp (a reservation system for airlines, initially for Air Canada), but that wasn't successful in the ma…

>Probably it's not that easy to replace Lisp for something else at Google, since it implements a relatively complex search engine core. Thus it's still used.

Thanks, makes sense.

>At Viaweb Lisp was used for an early web store maker (enables people to have their own webshop) implementation.

Yes, I had read PG's article about it ("Beating the Averages"). IIRC the templating language they used in ViaWeb, which allowed customers to customize their stores, was a killer feature, and relied heavily on some Lisp language feature, maybe macros.

Re: Using D to Create the World’s Fastest File System

#104

Post by 2bitencryption »

dvfjsdhgfv wrote: post #2

I discovered D is a secret weapon at several companies, but not all of them want to make it widely known...

why is it in a company's best interest to not evangelize the publicly-available tools it uses?

Microsoft/Amazon/Google are paying $$$ to increase availability of AI/machine learning education, because they want a knowledge pool to hire from. Wouldn't this be the same with languages?

Re: Using D to Create the World’s Fastest File System

#105

Post by jordigh »

nonsince wrote: post #85
tombert wrote: post #68

I have wondered for awhile now why Rust is getting all this attention of being "Like C but safe and cool!", but no one would mention D. I personally don't do systems programming because I'm not smart enough but the little bit I have done, I found D to be the most-natural feeling (even over Rust), and D has been around a lot longer. I suppose timing is everything for these kinds of things.

The main reason the way I see it is that a lot of people who still use C and C++ need maximum speed, and D is only memory-safe with its garbage collector enabled. This affects latency and adds overhead. For many cases using a garbage collector is fine, but D was trying to target video games and other spaces where the GC was not acceptable. So D allows you to turn the GC off, but then it's just a vastly less-mature C+…

Is the D GC actually that bad? Do we have benchmarks or something to prove that the GC means D is dead in the water? I always hear about this hypothetical danger of GC but my D usage hasn't found it and my D programs typically match or outperform my C++ programs. I mostly use it for numerical code, so maybe that's why I'm not feeling the pain of the GC?

To address your final point, I find D vastly superior to C++. Immensely, tremendously, bigly superior to C++. It's so nice, it's so pleasant, it's so easy. It's not an incremental change, it's a whole new world of no segfaults, no template metaprogramming, beautiful error messages, beautiful compile-time calculations.

Re: Using D to Create the World’s Fastest File System

#106

Post by burk96 »

z3t4 wrote: post #80
tombert wrote: post #68

I have wondered for awhile now why Rust is getting all this attention of being "Like C but safe and cool!", but no one would mention D. I personally don't do systems programming because I'm not smart enough but the little bit I have done, I found D to be the most-natural feeling (even over Rust), and D has been around a lot longer. I suppose timing is everything for these kinds of things.

The Rust community is extremely hostile, especially against other languages, and D in particular.

I think I know what you are talking about, there does seem to be a general sense of elitism in the Rust community. Kind of a thought that Rust is the best language for almost any task, why would you use anything else? I think that thought process is present in many software communities however.

I have found the Rust community to be one of the most helpful and welcoming to beginners, and I don't believe this to be contradictory of what I have mentioned before. Rust developers want their community to grow so to spread the good word. Maybe it comes off too strong sometimes by pointing out where Rust has strengths against other languages, but if that is the among worst the community does, I would consider the community pretty friendly.

Re: Using D to Create the World’s Fastest File System

#107

Post by billforsternz »

acd wrote: post #41

Weka is a name of a Machine learning product from New Zealand. The IBM system had 24xHGST N200 SSD, 830 000 random read, 200 000 random write. that is 24 * 200 000 IOPS=4.8Million random writes. The Matrix system had 64x1.2TB Micron 9100 SSDs. 750 000 random read, 300 0000 random writes. 64 * 300 000=19.2 Million IOPS Ok so you have benchmarked hardware with 4.8 Million write ops vs 19.2 Million write ops.

I clicked on the story in the hope that there was a New Zealand connection, and was disappointed that it seemed to be an Israeli operation.

Re: Using D to Create the World’s Fastest File System

#108

Post by WalterBright »

nonsince wrote: post #85
tombert wrote: post #68

I have wondered for awhile now why Rust is getting all this attention of being "Like C but safe and cool!", but no one would mention D. I personally don't do systems programming because I'm not smart enough but the little bit I have done, I found D to be the most-natural feeling (even over Rust), and D has been around a lot longer. I suppose timing is everything for these kinds of things.

The main reason the way I see it is that a lot of people who still use C and C++ need maximum speed, and D is only memory-safe with its garbage collector enabled. This affects latency and adds overhead. For many cases using a garbage collector is fine, but D was trying to target video games and other spaces where the GC was not acceptable. So D allows you to turn the GC off, but then it's just a vastly less-mature C+…

> D is only memory-safe with its garbage collector enabled.

This is technically correct, but not pragmatically correct. D doesn't have every memory unsafe operation plugged, but it's pretty darned close, and does have the major ones covered (like array bounds checking, alternatives to pointers, RAII, etc.).

> library support

D has excellent library support.

Re: Using D to Create the World’s Fastest File System

#109

Post by WalterBright »

nwah1 wrote: post #70
tombert wrote: post #68

I have wondered for awhile now why Rust is getting all this attention of being "Like C but safe and cool!", but no one would mention D. I personally don't do systems programming because I'm not smart enough but the little bit I have done, I found D to be the most-natural feeling (even over Rust), and D has been around a lot longer. I suppose timing is everything for these kinds of things.

D had a closed source reference compiler for a long time, and didn't have any major backers. Rust had Mozilla backing early, and was fully open and transparent in terms of community feedback, and wasn't just making a language that had high level features, but was pioneering a new category of language that added tons of safety guarantees at compile time by default using a new paradigm of enforcing borrowing and owners…

D's only runtime memory safety feature is array bounds checking. (The same as Rust, I believe.) The rest is compile time.

D's compile time memory safety focusses on:

1. @safe and @system code

2. disallowing unsafe pointer operations

3. safe alternatives to pointers

4. controlling escaping of pointers

5. controlling the scope of addresses

Re: Using D to Create the World’s Fastest File System

#110

Post by WalterBright »

hardwaresofton wrote: post #69
WalterBright wrote: post #13

Earlier quoted context omitted.

"C++ has a very complex ABI, and the Rust ABI is not frozen. However, both C++ and Rust support functions that use the C ABI. Therefore, interoperability between C++ and Rust involves writing things in such a way that C++ sees Rust code as C code and Rust sees C++ code as C code." https://hsivonen.fi/modern-cpp-in-rust/

Context: this poster is likely Walter Bright the creator and first implementer of D lang itself. Cool to know you also read that article about C++ in rust (I personally read a little bit then left because trying to interface with C++ from rust wasn't a problem I had), but I guess it's obvious that you would.

> is likely

Probably 100%

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