Re: question about tasks, multithreading and multi-cpu machines

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Maciej Sobczak <no.spam@no.spam.com> writes:

> Jeffrey Creem wrote:
> 
> > Actually, threads is misleading since threads are just tasks minus
> > rendevous. It all just depends on your perspective. Since Ada had
> > tasking before (most) unix had threads I think Unix got the name wrong
> > :)
> 
> In my humble opinion, Ada got it wrong in the first place.

I tend to agree that "thread" is a better term than "task".
But I think you get it wrong when you say "wrong".  ;-)
It's wrong to call names-for-things "wrong" -- they are just
conventions.  See Lewis Carrol.

> The tasks in Ada do not match any of the above. Other languages (for
> example Java) also got it wrong, by treating threads as objects or even
> by allowing a programmer to "subclass" or "specialize" a thread
> class. None of the languages that I'm aware of allows me to treat tasks
> and threads as they really are, which means that everybody got it wrong
> in one way or another. :)

I don't understand why "threads as objects" seems wrong to you.

> > So, the only thing I am trying to say here is that people seem to
> > assume that task, thread and process have some formal definition that
> > is all powerful. This is not true.
> 
> Right.

Right.  Task, thread, and process have all been used interchangeably in
the past.  These days, "process" seems to imply a separate memory
context, though.

- Bob