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- ;; This replaces trans-id REF in Reppy's code
- (define-synchronized-record-type trans-id :trans-id
- (really-make-trans-id thread-cell value)
- (value)
- trans-id?
- (thread-cell trans-id-thread-cell)
- (value trans-id-value set-trans-id-value!))
-
- (define (make-trans-id)
- (really-make-trans-id (make-cell (current-thread))
- #f))
- (define (maybe-commit-and-trans-id-value trans-id)
- (cond
- ((trans-id-value trans-id)
- => (lambda (value)
- (and (maybe-commit)
- value)))
- (else
- (and (maybe-commit-and-block (trans-id-thread-cell trans-id))
- (trans-id-value trans-id)))))
- (define (trans-id-set-value! trans-id value)
- (cond
- ((not value) (error "trans-id value can't be #f" trans-id value))
- ((trans-id-value trans-id)
- (error "trans-id is already assigned"))
- (else
- (set-trans-id-value! trans-id value))))
- (define (trans-id-cancelled? trans-id)
- (and (trans-id-value trans-id) #t))
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