J3/06-342

To: J3
From: Dick Hendrickson
Subject: Co-arrays and processor dependent order
References: J3/06-007R1, 06-278, 06-279
Date: Oct. 31, 2006

These comments are gleaned from 06-278 and 06-279 which were
deferred at meeting 177.

Page 71:11 says the order in which things are finalized is
processor dependent. Page 130:15 says it is processor
dependent whether or not an allocated object retains its
allocation status. Page[131:14-16] also mention automatic
operations without an order. Does processor dependent allow
different images to do things differently? Can an object be
deallocated on some images and not on others? Can
different images finalize things in different orders? I don’t
know if it matters in the co-array sense; but I don’t think we
say which it should be anyplace.

Are co-arrays expected to work on different kinds of hardware
in a network? It’s maybe reasonable to expect wildly different
hardware and OSs to have different memory management methods
and, maybe, to link things in different orders and do the
deallocate, or whatever, in a different order. Is this allowed
or prohibited?

Either way, I think some words in 2.3.2 would help.

For what it’s worth, many of the clause 13 collective
Functions say something like "processor-dependent and image-
dependent..."

For [130:15] Malcolm suggests saying it in only the correct
place and replacing the text with
"Deallocation of allocatable components can also occur during
intrinsic assignment (7.4.1.3)."