(use srfi-18 srfi-69 synch miscmacros)

(define-record-type foo
  (make-foo x y mtx)
  foo?
  (x foo-x)
  (y foo-y)
  (mtx foo-mutex))
  
(define tfoo (make-foo 1 2 (make-mutex)))
(print "*** prints 1 2 ***")
(record/synch foo tfoo (print (foo-x tfoo) " " (foo-y tfoo)))
(newline)

;;

(define (hash-table-count ht)
  (##sys#check-structure ht 'hash-table 'hash-table-count)
  (hash-table-fold ht (lambda (k v a) (fx+ a 1)) 0) )

;;;

(define-constructor/synch make-hash-table hash-table/synch:)
(define-predicate/synch hash-table?)
(define-operation/synch hash-table-count)
(define-operation/synch hash-table-set!)

;;

(define +tht+ (make-hash-table/synch = number-hash))

;; Greedy reader

(define (reader)
  (do ((n (hash-table-count/synch +tht+) (hash-table-count/synch +tht+)))
      ((fx= 20 n) (print "test hash-table count = " n " so quit"))
    (print "test hash-table count = " n) ) )
(define reader-thread (make-thread reader 'reader))
(thread-start! reader-thread)

;; Cooperative writer

(define (writer)
  (repeat* 10
    (hash-table-set!/synch +tht+ it (number->string it))
    (hash-table-set!/synch +tht+ (* it 11) (number->string it))
    (thread-yield!) ) )
(define writer-thread (make-thread writer 'writer))
(thread-start! writer-thread)

;;

(thread-join! writer-thread)
(thread-join! reader-thread)