7491e172ea
The eopl language is now racket-based rather than mzscheme-based. This test-suite, which was originally distributed on the book's web-site has been re-written in the new language. Changes include dropping all drscheme-init.scm and top.scm files. Remaining files were renamed to use the .rkt extension and edited to use the #lang syntax (instead of modulue). Require and provide forms were changed to reflect racket's syntax instead of mzscheme's (eg, only-in vs. only). Several occurrences of one-armed ifs were changed to use when and unless. All tests have been run successfully.
78 lines
1.9 KiB
Racket
Executable File
78 lines
1.9 KiB
Racket
Executable File
#lang eopl
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(require "queues.rkt")
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(require "data-structures.rkt") ; for continuation?
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(require "lang.rkt") ; for expval?
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(provide
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initialize-scheduler!
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set-final-answer!
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time-expired?
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decrement-timer!
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place-on-ready-queue!
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run-next-thread
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)
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;;;;;;;;;;;;;;;; the state ;;;;;;;;;;;;;;;;
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;; components of the scheduler state:
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(define the-ready-queue 'uninitialized)
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(define the-final-answer 'uninitialized)
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(define the-max-time-slice 'uninitialized)
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(define the-time-remaining 'uninitialized)
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;; initialize-scheduler! : Int -> Unspecified
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(define initialize-scheduler!
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(lambda (ticks)
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(set! the-ready-queue (empty-queue))
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(set! the-final-answer 'uninitialized)
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(set! the-max-time-slice ticks)
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(set! the-time-remaining the-max-time-slice)
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))
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;;;;;;;;;;;;;;;; the final answer ;;;;;;;;;;;;;;;;
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;; place-on-ready-queue! : Thread -> Unspecified
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;; Page: 184
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(define place-on-ready-queue!
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(lambda (th)
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(set! the-ready-queue
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(enqueue the-ready-queue th))))
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;; run-next-thread : () -> FinalAnswer
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;; Page: 184
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(define run-next-thread
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(lambda ()
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(if (empty? the-ready-queue)
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the-final-answer
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(dequeue the-ready-queue
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(lambda (first-ready-thread other-ready-threads)
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(set! the-ready-queue other-ready-threads)
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(set! the-time-remaining the-max-time-slice)
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(first-ready-thread)
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)))))
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;; set-final-answer! : ExpVal -> Unspecified
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;; Page: 184
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(define set-final-answer!
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(lambda (val)
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(set! the-final-answer val)))
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;; time-expired? : () -> Bool
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;; Page: 184
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(define time-expired?
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(lambda ()
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(zero? the-time-remaining)))
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;; decrement-timer! : () -> Unspecified
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;; Page: 184
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(define decrement-timer!
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(lambda ()
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(set! the-time-remaining (- the-time-remaining 1))))
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