Is D right for me?

[Fawzi Mohamed]

On 12-ott-10, at 13:04, Denis Koroskin wrote:

> On Tue, 12 Oct 2010 02:32:55 +0400, Andrei Alexandrescu <SeeWebsiteForEmail at erdani.org 
> > wrote:
>
>> On 10/11/2010 12:38 PM, Daniel Gibson wrote:
>>> But parts of phobos are deprecated or will be deprecated and there  
>>> still
>>> is no alternative for them.
>>> That may prevent people from writing "real" projects in D2 (or D  
>>> at all)
>>> - who wants to use classes that will be deprecated soon?
>>> Sure, that old stuff will not be removed and can still be used,  
>>> but I
>>> personally feel a bit uncomfortable with using deprecated code.
>>
>> Agreed. Maybe this is a good time to sart making a requirements  
>> list for streams. What are the essential features/feature groups?
>>
>> Andrei
>
> For me, I/O should be scalable (and thus support async operations)  
> so I came up with my own implementation.
> I've tried building it on top of std.concurrency, but it doesn't  
> scale either. So, once again, I had to implement my own message  
> passing mechanism. I can implement existing std.concurrency  
> interface on top of my own one without sacrificing anything, but not  
> vice-versa).	

I very much agree that IO should be scalable.
In my opinion this is possible if one has a robust framework for smp  
parallelization.
This is what I have been working on with blip http://dsource.org/blip .
The API is fixed, and seem to work correctly in all the cases I  
tested. It has not been optimized so it still has obvious  
optimizations, but I wanted to have a bit more of code using it,  
before thinking about optimization (so that I will be able to catch  
wrong optimizations with a high probability).
Indeed I have already a rather large amount of code using it, and had  
still cases where bugs were *very* rare and difficult to locate.
Still I already used it for example to build a socket server that uses  
all available threads efficiently to implement rpc between processes.
One important thing in my opinion is that idle work should not use  
resources: waiting for i/o, waiting for events uses basically no cpu.

All this is with D 1.0, and tango (even if I did try to reduce and  
encapsulate the dependence on tango as much as possible).
For example when using sockets one does not see the blocking by  
default (for a webserver one will likely want to add some timeout),  
and the processor transparently switches to fibers that have work to do.
The programmer has to just think about tasks and things that can be  
executed in parallel, if possible, the optimal scheduling and mapping  
to threads is done automatically.

Fawzi