thread-test.lisp

(defmacro with-repeating (threads repetitions &rest body)
  `(mapc #'sb-thread:join-thread
        (loop repeat ,threads
              collect (sb-thread:make-thread
                       (lambda () (loop repeat ,repetitions do ,@body))))))

(defstruct atomic-var
  (data 0 :type (unsigned-byte 64)))

(proclaim '(optimize (safety 0) (speed 3)))
(defun increment-value ()
  (let ((x (make-atomic-var :data 0)))
    (with-repeating 1000 1000
      (sb-ext:atomic-incf (atomic-var-data x) 1))
    x))


;; The below numbers are almost identical with and without proclaim.
;;
;; CL-USER> (time (increment-value))
;; Evaluation took:
;;   0.052 seconds of real time
;;   0.087489 seconds of total run time (0.059310 user, 0.028179 system)
;;   167.31% CPU
;;   908,464 bytes consed
;;
;; #S(ATOMIC-VAR :DATA 1000000)