CVS difference for ais/ai-00210.txt
--- ais/ai-00210.txt 1998/10/01 19:10:53 1.2
+++ ais/ai-00210.txt 1999/03/30 00:33:15 1.3
@@ -1,31 +1,49 @@
-!standard H.4 (24) 98-10-01 AI95-00210/00
+!standard H.4 (24) 99-03-23 AI95-00210/01
!standard H.4 (27)
!class confirmation 98-10-01
+!status work item 99-03-23
!status received 98-10-01
!subject Questions on pragma Restriction No_Recursion and No_Reentrancy
+The No_Recursion and No_Reentrancy restrictions need not be
+checked statically, nor at run-time. A program execution is erroneous
+if it violates either of these restrictions when they have been
+specified for the partition.
+Both of these restrictions apply to the run-time system if
+specified for a partition.
Neither pragma Restriction(No_Recursion) nor pragma
Restriction(No_Reentrancy) can (in general at least) be checked statically.
-Must we make run-time tests in order to conform with Annex H?
+Must we make run-time tests in order to conform with Annex H? (No.)
+Do pragma Restriction(No_Recursion) and pragma
+Restriction(No_Reentrancy) apply to the runtime system? (Yes.)
-Does pragma Restriction(No_Recursion) and pragma
-Restriction(No_Reentrancy) apply to the runtime system?
-Making a RTS that is free of Recursion is of course possible. However,
-a RTS that is not reentrant does not make much sense. For instance, on
+Making an RTS that is free of recursion is of course possible. However,
+an RTS that is not reentrant does not make much sense. For instance, one
task can be suspended in an accept statement while another task calls an
+Although restrictions must generally be enforced prior to
+execution, per 13.12(8), this requirement can be relaxed
+for particular restrictions. In the case of No_Recursion and
+No_Reentrancy, violating these restrictions is specified as erroneous
+(see H.4(27)). Hence, these restrictions need not be enforced
+prior to execution, nor at run-time.
+H.4(24) indicates that No_Recursion and No_Reentrancy apply
+to the run-time system as well as to the user's program units.
!topic Must pragma Restriction(No_Recursion) and pragma
<<reference as: 1998-15856.a Sven H. Sorensen 1998-4-24>>
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