Re: asynchronous task communication

[Shark8 <onewingedshark@gmail.com>]

On Monday, December 31, 2012 12:52:22 PM UTC-6, Charles Hixson wrote:
> Thank you for your answer.
> 
> The problem with that solution is that I've been advised that I 
> shouldn't have many more tasks than available cores, and that uses 2 of 
> my available 6.  True, several clients could use the same postmaster, 
> but it's still too resource intensive.

I'm rather dubious of this advice -- without any reasoning it reeks of the "premature optimization" problem.

Besides, unless you're making it for a specific [homogenized] computer platform (I.E. the PlayStation 2) there's no guarantee that the user will have the same set-up... further, it restricts you to your particular computer. (I recently got a new computer, which has a different number of cores than my old one... I would not like to be compelled to recompile my programs because of such a minor difference.)


> It's looking more and more like protected objects on the heap are the 
> best answer.  I just wasn't sure that a built-in answer didn't exist.

Protected objects are pretty nice, so are the Containers (w/ the generalized for-loop). But if it's something that logically maps well to TASK, there's no reason to avoid TASK -- that is, conform your code to the problem, not to the details of the executing computer.

> OTOH, actual non-blocking (i.e. asynchronous) calls to either threads or 
> protected items is what I really need.

Ada can do it; I don't have my books available, but I believe asynchronous select is covered in both:
http://www.amazon.com/Building-Parallel-Embedded-Real-Time-Applications/dp/0521197163/ref=sr_1_2?ie=UTF8&qid=1356984746&sr=8-2&keywords=Ada+Parallel+programming
and
http://www.amazon.com/Concurrent-Real-Time-Programming-Ada-ebook/dp/B001GS6TBO/ref=sr_1_3?ie=UTF8&qid=1356984746&sr=8-3&keywords=Ada+Parallel+programming

Or just go to the RM:
 http://www.ada-auth.org/standards/12aarm/html/AA-9-7-4.html

> These other things are make-shift kludges.  They centralize control that should be distributed. 

Hm, then should you be looking at the DSA? -- Or is that a different 'distributed' than you are talking about?