Source

clojurian / clojurian-atom.scm

(module clojurian-atom

(atom atom-value atom? atom-compare-and-set! atom-swap! atom-reset!)

(import chicken scheme)
(use srfi-18)

(define-record atom
  mutex value)

(define (atom value)
  (make-atom (make-mutex) value))

(define (atom-compare-and-set! atom old new)
  (and (eq? (atom-value atom) old)
       (dynamic-wind
           (lambda ()
             (mutex-lock! (atom-mutex atom)))
           (lambda ()
             (and (eq? (atom-value atom) old)
                  (begin
                    (atom-value-set! atom new)
                    #t)))
           (lambda ()
             (mutex-unlock! (atom-mutex atom))))))

(define (atom-swap! atom proc . args)
  (let loop ()
    (let* ((old (atom-value atom))
           (new (apply proc old args)))
      (if (atom-compare-and-set! atom old new)
          new
          (loop)))))

(define (atom-reset! atom value)
  (dynamic-wind
      (lambda ()
        (mutex-lock! (atom-mutex atom)))
      (lambda ()
        (atom-value-set! atom value)
        value)
      (lambda ()
        (mutex-unlock! (atom-mutex atom)))))

)
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.