6.5.3.1 Multiple threads

By binding *inferencing-state* around all KnowledgeWorks operations in a thread's main function as in the example below, its value can be unique to each thread.

(defun test-1-counter (name)

  (let* ((*inferencing-state* nil)

         (step (1+ (random 10)))

         (limit (* step (+ 2000 (random 100)))))

    (unwind-protect

        (progn

          (setq *inferencing-state*

                (make-inferencing-state name))

          (make-instance 'counter

                         :value limit

                         :step step)

          (infer))

      (destroy-inferencing-state *inferencing-state*))))

(mp:process-run-function (format nil "Test ~D" index)

                         '()

                         'test-1-counter

                         (gensym)

KnowledgeWorks and Prolog User Guide (Unix version) - 6 Dec 2011