Re: Private or public task ?

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

Martin <martin.dowie@btopenworld.com> writes:

> It's isn't predicatable - it will delay for /at least/
> Some_Static_Constant.

Well, implementations are supposed to wake the task up
as soon as possible after the delay expires.
We don't really have a way to say that in RM terms,
but an implementation that delays for an extra
second, for example, should probably be considered
broken.

>..It's up to the task scheduling algorithm (plus
> the rest of the program! ;-) as to what happen next...and when!

Yeah, the rest of the program is key.  But that's the case even
without delays.  For example, suppose a protected procedure
says, "X := X + 1;".  Looks pretty bounded.  But it can
get preempted by a higher priority task, which can
go off and do stuff for a long and unbounded time.

You have to take care to get your priorities right.

- Bob