Re: Concurrency in Gnat 3.05?

[dewar@cs.nyu.edu (Robert Dewar)]

Jerry said

"But what you probably wanted to ask is: does GNAT/DOS do multi-tasking ?
The answer, yes. But not pre-emptive tasking, what seems to be what you
expected, but cooperative tasking."


That's wrong, of course GNAT/DOS implements pre-emptive tasking, this is
required by Ada semantics (i.e. when a high priority task becomes ready,
it preempts a low priority running task). This certainly works, or if it
does not, then it is a bug -- well actually that's not quite fair. Priorities
and preemptive tasking are only required by Annex D, not by the core
language.

But in any case, it is I think clearly established by later psts in the
thread (Jerry maybe your newsreader is way behind, or perhaps you are not
following threads before answering) that the issue is time slicing among
tasks of equal priority, which requires preemption of course, but should
not be confused with the issue of whether or not preemptive tasking
is implemented.