Re: Complexity of protected objects

[dewar@gnat.com (Robert Dewar)]

"Marin David Condic" <dont.bother.mcondic.auntie.spam@[acm.org> wrote in message news:<a5dpnv$p6n$1@nh.pace.co.uk>...
> I don't know of any natural limitations that would make 
> it A Bad Thing to have a very large protected object. 
> AFAIK, its only a concern for how long
> it will block execution of other tasks that limit size.

There are none
 
> The rest would be
> whatever limitations your compiler may impose.

A compiler that imposes arbitrary limits on the complexity
of protected types is broken (of course in specialized
subsets, like Ravenscar, such restrictions may serve a
specific purpose).

Remember that the key point about protected objects is the
ceiling priority protocol, which ensures that higher priority tasks
can still freely interrupt the lower priority tasks inside a PO with a
lower CP. Thus it is
quite reasonable to use complex PO's with a low CP for
communication between low priority tasks without any
danger of intefering with high priority tasks (even in
an implementation that has no locks).