[cs63201] Re: homework question

[Mikhail Nesterenko]

vlee at cs.kent.edu wrote:
> Some students and I seem to be interpreting question 3 differently.
> In question 3 on the homework, when you say,
> 
>     there are two statements for guarded command.  A statement
>     is either sending a message or local computation.  The atomicity
>     for the program is a statement (not a guarded command). The
>     execution semantics is interleaving.
> 
> Are you defining statementA1 and statementA2 to be executed strictly
> sequentially, or concurrently, or not defined in the problem statement?
> Thank you.
> 
>           *[
> 	     local variable-predicate1 -->
> 	                        statementA1;
> 				statementB1;
> 	     local variable-predicate2 -->
> 	                        statementA2;
> 				statementB2;
> 	     receive message from another process -->
> 	                        statementR1;
> 				statementR2;
> 	   ...
>            ]

The semantics is interleaving. That is only one statement (in the
whole system) is executed at a time. Due to the statements' atomicity
The execution of any two statements does not overlap.

thanks,
--
Mikhail