1 / 20

Distributed Meta-Programming

Distributed Meta-Programming. Rui Shi , Chiyan Chen and Hongwei Xi Boston University. Outline. MP vs. DMP Typeful Code Representation The Language  dist The Language  + dist Discussion and Conclusion. Meta-Programming. (define (run code) (eval code nil))

chadwick-mills
Download Presentation

Distributed Meta-Programming

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Distributed Meta-Programming Rui Shi, Chiyan Chen and Hongwei Xi Boston University

  2. Outline • MP vs. DMP • Typeful Code Representation • The Language dist • The Language +dist • Discussion and Conclusion

  3. Meta-Programming (define (run code) (eval code nil)) (define (power n x)(if (= n 0) 1 `(* ,x ,(power (- n 1) x)))) ;;; (power 2 ‘x) yields (* x (* x 1)) (define square(run `(lambda (x) ,(power 2 ‘x)))) ;;; (power 3 ‘y) yields (* y (* y (* y 1))) (define cube(run `(lambda (y) ,(power 3 ‘y))))

  4. Distributed Meta-Programming Run-time code generation Distributed execution Code Code

  5. Outline • MP vs. DMP • Typeful Code Representation • The Language dist • The Language +dist • Discussion and Conclusion

  6. Un-typed Code Representation • No guarantee on the safety of generated code. • Code can be syntactically ill-formed or ill-typed, whichlead to run-time errors when executed at remote sites. • Issues of locality and heterogeneity of resources • Different sites may have different resources and thus likely to provide different services. `(“abc” + 10) (ill-typed) `(( y.x) 10) (open code) f : (Int ! Int)@L `(f 100) L L’

  7. Typeful Code Representation (T.C.R) • The types of object programs can be reflected in the types of meta programs • E.g. code of type h, T i represents an object program of type T under the type environment . • The type of the code also reflects where it should be sent for execution. • E.g. code of type h L, , T ican be sent to location Lfor execution. • The compiler can statically guarantee that only well-typed code can be constructed at run-time and sent to proper locations for execution.

  8. Outline • MP vs. DMP • Typeful Code Representation • The Language dist • The Language +dist • Discussion and Conclusion

  9. The Language dist

  10. First-Order Code Constructors For example, the term  x. y. y (x) can be represented as: which can be of type (with static variables properly instantiated) Lam (Lam (App (One) (Shi (One)))) 8 . h, , int ! (int ! int) ! int i

  11. Some Primitive Functions

  12. Constant Messages • Constant messages refer to the messages which can be interpreted at all sites. • Example: perform addition of two integersat remote site

  13. An Example in dist f : (Int ! Int)@L `(f 100) L rgetint (L, rexec (L, App (Lift (n2m f)), Lift 100) )) of type h L, , int i

  14. Outline • MP vs. DMP • Typeful Code Representation • The Language dist • The Language +dist • Discussion and Conclusion

  15. The Language +dist • We extend dist to +dist with some language constructs adopted from meta-programming (supported in Scheme and MetaML): • `(e) for the code representation of e • ^(e) for spliceing the code e into some context • %(¢) is a shorthand for ^(Lift(¢))

  16. An Example in Concrete Syntax of +dist typedef CodeType (L: loc) = <L, nil, (int -> int) -> int> fun rZeroFind2{L:loc} (L:loc(L)) (n: (int -> int) @ L) : int = let val zeroFindCode : CodeType (L) = `(lam f => (fix aux i => if f (i) = 0 then i else aux (i+1)) 0) in rexecInt (L, `(^zeroFindCode %(n2m n))) end

  17. Outline • MP vs. DMP • Typeful Code Representation • The Language dist • The Language +dist • Discussion and Conclusion

  18. Discussion • We have a transformation scheme from +dist to dist to justify the soundness of +dist . • We have a process to elaborate programs (partial type inference)in the concrete syntax to the formal syntax of +dist • DMP is implemented as a part of ATS (Applied Type System) framework.

  19. Conclusion • A simple and general approach to support typed mobile computing. • Combines meta-programming with distributed programming in a coherent manner. • In future, we are planning to study issues such as exception handling and distributed garbage collection in this context.

  20. Thank You!

More Related