Exercise 3.40 · 习题

Exercise 3.40: Give all possible values of
x that can result from executing

(define x 10)
(parallel-execute
(lambda () (set! x (* x x)))
(lambda () (set! x (* x x x))))

Which of these possibilities remain if we instead use serialized procedures:

(define x 10)

(define s (make-serializer))

(parallel-execute

(s (lambda () (set! x (* x x))))

(s (lambda () (set! x (* x x x)))))

练习 3.40：给出执行下列代码后 x 所有可能的值：

(define x 10)
(parallel-execute
(lambda () (set! x (* x x)))
(lambda () (set! x (* x x x))))

如果改用串行化过程，哪些可能性会保留？

(define x 10)
(define s (make-serializer))
(parallel-execute
(s (lambda () (set! x (* x x))))
(s (lambda () (set! x (* x x x)))))