--- /dev/null
+;;;; testing add/remove-method thread thread safety
+
+;;;; This software is part of the SBCL system. See the README file for
+;;;; more information.
+;;;;
+;;;; While most of SBCL is derived from the CMU CL system, the test
+;;;; files (like this one) were written from scratch after the fork
+;;;; from CMU CL.
+;;;;
+;;;; This software is in the public domain and is provided with
+;;;; absolutely no warranty. See the COPYING and CREDITS files for
+;;;; more information.
+
+(defpackage "CLOS-ADD/REMOVE-METHOD"
+ (:use "COMMON-LISP" "SB-THREAD"))
+
+(in-package "CLOS-ADD/REMOVE-METHOD")
+
+;;; We make a generic function, add a bunch of method for it, and
+;;; prepare another bunch of method objects for later addition.
+;;;
+;;; Then we run several threads in parallel, removing all the old
+;;; ones and adding all the new ones -- and finally we verify that
+;;; the resulting method set is correct.
+
+(defgeneric foo (x))
+
+(defvar *to-remove-a* nil)
+(defvar *to-remove-b* nil)
+(defvar *to-remove-c* nil)
+(defvar *to-add-d* nil)
+(defvar *to-add-e* nil)
+(defvar *to-add-f* nil)
+
+(defun name (key n)
+ (intern (format nil "FOO-~A-~A" key n)))
+
+(defun names (key)
+ (loop for i from 0 upto 128
+ collect (name key i)))
+
+(defun to-remove (key)
+ (loop for s in (names key)
+ collect
+ `(progn
+ (defclass ,s () ())
+ (defmethod foo ((x ,s))
+ ',s)
+ (push (find-method #'foo nil (list (find-class ',s)) t)
+ ,(intern (format nil "*TO-REMOVE-~A*" key))))))
+
+(defun to-add (key)
+ (loop for s in (names key)
+ collect
+ `(progn
+ (defclass ,s () ())
+ (push (make-instance
+ 'standard-method
+ :qualifiers nil
+ :specializers (list (find-class ',s))
+ :function (lambda (args next)
+ (declare (ignore args next))
+ ',s)
+ :lambda-list '(x))
+ ,(intern (format nil "*TO-ADD-~A*" key))))))
+
+(macrolet ((def ()
+ `(progn
+ ,@(to-remove 'a)
+ ,@(to-remove 'b)
+ ,@(to-remove 'c)
+ ,@(to-add 'd)
+ ,@(to-add 'e)
+ ,@(to-add 'f))))
+ (def))
+
+(defvar *run* nil)
+
+(defun remove-methods (list)
+ (loop until *run*)
+ (dolist (method list)
+ (remove-method #'foo method)))
+
+(defun add-methods (list)
+ (loop until *run*)
+ (dolist (method list)
+ (add-method #'foo method)))
+
+#+sb-thread
+(let ((threads (list (make-thread (lambda () (remove-methods *to-remove-a*)))
+ (make-thread (lambda () (remove-methods *to-remove-b*)))
+ (make-thread (lambda () (remove-methods *to-remove-c*)))
+ (make-thread (lambda () (add-methods *to-add-d*)))
+ (make-thread (lambda () (add-methods *to-add-e*)))
+ (make-thread (lambda () (add-methods *to-add-f*))))))
+ (setf *run* t)
+ (mapcar #'join-thread threads))
+
+#-sb-thread
+(progn
+ (setf *run* t)
+ (remove-methods *to-remove-a*)
+ (remove-methods *to-remove-b*)
+ (remove-methods *to-remove-c*)
+ (add-methods *to-add-d*)
+ (add-methods *to-add-e*)
+ (add-methods *to-add-f*))
+
+(let ((target (append *to-add-d* *to-add-e* *to-add-f*))
+ (real (sb-mop:generic-function-methods #'foo)))
+ (assert (subsetp target real))
+ (assert (subsetp real target)))