CVS difference for ai12s/ai12-0048-1.txt

Differences between 1.4 and version 1.5
Log of other versions for file ai12s/ai12-0048-1.txt

--- ai12s/ai12-0048-1.txt	2013/05/09 01:39:14	1.4
+++ ai12s/ai12-0048-1.txt	2013/06/09 05:13:43	1.5
@@ -1817,3 +1817,31 @@
+From: Alan Burns
+Sent: Thursday, May 30, 2013  8:18 AM
+There has been discussions on these AIs from within the IRTAW 'community'.
+Our views are as follows (note we also looked at AI-0048 as well).
+... [Only relevant part here - Editor.]
+The summary here expresses exactly what should happen:
+"In the absence of any setting of the CPU of a task and the creation of any 
+dispatching domains, a partition that specifies a language-defined dispatching
+policy will allow all tasks to run on all processors. "
+There seems to be a concern that in a (full Ada) program that does not use
+dispatching domains or CPU aspect then priority inversion could occur as the
+implementation might use static allocation. This seems to be an erroneous
+implementation. I would expect global scheduling. OK it might take time for a
+task to reach a dispatching point to trigger dispatching, but a global scheme
+is expected.
+So here there is a conceptual model of distinct sets of ready queues, but the
+implementation may well be better placed to use a shared single ready queue. 
+Alternatively if an implementation cannot support FIFO_Within_Priority then it
+should supply an alternative policy.

Questions? Ask the ACAA Technical Agent