CODEWITHSUNDEEP
stackcomputer-science
Vladimir
Vladimir

Reputation: 1243

Show the stack with all activation record instances, including static and dynamic chains

Show the stack with all activation record instances, including static and dynamic chains, when execution reaches the indicated position in the skeleton program below. Assume Bigsub is a level 1 and the order of subprogram invocation is Bigsub calls A, A calls B, B calls A, A calls C, C calls D.

procedure Bigsub;
    procedure C; forward;
    procedure A;
       procedure B;
       end;  {B}
    end;  {A}
    procedure C;
       procedure D;
      *** Here is the point ***
       end;  {D}
    end;  {C}
 end;  {Bigsub}

I have some questions similar to this one. I don't understand what exactly is asked, what are dynamic and static chains. I have this image below which shows the stack and that's what I understand, but I don't what those arrows represent. Also, does the image lack activation record instaces or is it good as a solution? enter image description here

Upvotes: 0

Views: 5499

Answers (1)

kupaff
kupaff

Reputation: 329

A static chain is a chain of static links that connect certain activation record instances in the stack. dynamic chains is a collection of dynamic links in the stack at a given time. In your case whenever you say this "calls" that then add a dynamic chain there.As for static chain, you just have to see which function is static to which one.one. Ok for example C is nesting D so C and D has static chain as so forth.

Upvotes: 2

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