;;; Test for shared writes to a single hash entry for ABCL

#|
Use:

(run 2) 

(run 1000) 

|#

(defparameter *shared* (make-hash-table :test 'equal))

(defun increment (n)
  (sleep (/ (random 1000) 1000))
  (loop :for i :below n
     :doing (progn 
	      (sleep (/ (random 1000) 1000))
	      (setf (gethash 1 *shared*)
		    (1+ (or (gethash 1 *shared*)
			    0)))))
  n)

(defun run (threads)
  (clrhash *shared*)
  (format t "~&Spawning ~A threads..." threads)
  (format t " Done.~%Spawned threads that should sum to ~A while the shared value is ~A.~%"
	  (loop :for thread :in 
	     (loop :for i :below threads
		:collect (threads:make-thread (lambda () (increment 10))))
	     :summing (threads:thread-join thread))
	  (gethash 1 *shared*)))