X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fpcl%2Fstd-class.lisp;h=b1a60df4485fd3674bf98d42f4da7d454b5d0ef7;hb=4d31006db24db375cdb83a5726d66c524b36689c;hp=3acc5db71b5d32d3ace15e3adcc618295abb0891;hpb=603af6830a9c242adcec3fe3549e74e04cbe3228;p=sbcl.git

diff --git a/src/pcl/std-class.lisp b/src/pcl/std-class.lisp
index 3acc5db..b1a60df 100644
--- a/src/pcl/std-class.lisp
+++ b/src/pcl/std-class.lisp
@@ -69,8 +69,8 @@
               (the fixnum (logand (the fixnum (lognot mask)) flags)))))
   value)
 
-(defmethod initialize-internal-slot-functions ((slotd
-                                                effective-slot-definition))
+(defmethod initialize-internal-slot-functions
+    ((slotd effective-slot-definition))
   (let* ((name (slot-value slotd 'name))
          (class (slot-value slotd '%class)))
     (dolist (type '(reader writer boundp))
@@ -79,6 +79,33 @@
                               (writer '(setf slot-value-using-class))
                               (boundp 'slot-boundp-using-class)))
              (gf (gdefinition gf-name)))
+        ;; KLUDGE: this logic is cut'n'pasted from
+        ;; GET-ACCESSOR-METHOD-FUNCTION, which (for STD-CLASSes) is
+        ;; only called later, because it does things that can't be
+        ;; computed this early in class finalization; however, we need
+        ;; this bit as early as possible.  -- CSR, 2009-11-05
+        (setf (slot-accessor-std-p slotd type)
+              (let* ((std-method (standard-svuc-method type))
+                     (str-method (structure-svuc-method type))
+                     (types1 `((eql ,class) (class-eq ,class) (eql ,slotd)))
+                     (types (if (eq type 'writer) `(t ,@types1) types1))
+                     (methods (compute-applicable-methods-using-types gf types)))
+                (null (cdr methods))))
+        (setf (slot-accessor-function slotd type)
+              (lambda (&rest args)
+                ;; FIXME: a tiny amount of wasted SLOT-ACCESSOR-STD-P
+                ;; work here (see KLUDGE comment above).
+                (let ((fun (compute-slot-accessor-info slotd type gf)))
+                  (apply fun args))))))))
+
+(defmethod finalize-internal-slot-functions ((slotd effective-slot-definition))
+  (let* ((name (slot-value slotd 'name)))
+    (dolist (type '(reader writer boundp))
+      (let* ((gf-name (ecase type
+                              (reader 'slot-value-using-class)
+                              (writer '(setf slot-value-using-class))
+                              (boundp 'slot-boundp-using-class)))
+             (gf (gdefinition gf-name)))
         (compute-slot-accessor-info slotd type gf)))))
 
 ;;; CMUCL (Gerd PCL 2003-04-25) comment:
@@ -98,17 +125,13 @@
 (defmethod compute-slot-accessor-info ((slotd effective-slot-definition)
                                        type gf)
   (let* ((name (slot-value slotd 'name))
-         (class (slot-value slotd '%class))
-         (old-slotd (find-slot-definition class name))
-         (old-std-p (and old-slotd (slot-accessor-std-p old-slotd 'all))))
+         (class (slot-value slotd '%class)))
     (multiple-value-bind (function std-p)
-        (if (eq *boot-state* 'complete)
+        (if (eq **boot-state** 'complete)
             (get-accessor-method-function gf type class slotd)
             (get-optimized-std-accessor-method-function class slotd type))
       (setf (slot-accessor-std-p slotd type) std-p)
-      (setf (slot-accessor-function slotd type) function))
-    (when (and old-slotd (not (eq old-std-p (slot-accessor-std-p slotd 'all))))
-      (push (cons class name) *pv-table-cache-update-info*))))
+      (setf (slot-accessor-function slotd type) function))))
 
 (defmethod slot-definition-allocation ((slotd structure-slot-definition))
   :instance)
@@ -151,7 +174,7 @@
 ;;; here, the values are read by an automatically generated reader method.
 (defmethod add-direct-subclass ((class class) (subclass class))
   (with-slots (direct-subclasses) class
-    (pushnew subclass direct-subclasses)
+    (pushnew subclass direct-subclasses :test #'eq)
     subclass))
 (defmethod remove-direct-subclass ((class class) (subclass class))
   (with-slots (direct-subclasses) class
@@ -173,15 +196,40 @@
 ;;; In each case, we maintain one value which is a cons. The car is the list
 ;;; methods. The cdr is a list of the generic functions. The cdr is always
 ;;; computed lazily.
+
+;;; This needs to be used recursively, in case a non-trivial user
+;;; defined ADD/REMOVE-DIRECT-METHOD method ends up calling another
+;;; function using the same lock.
+(defvar *specializer-lock* (sb-thread::make-spinlock :name "Specializer lock"))
+
+(defmethod add-direct-method :around ((specializer specializer) method)
+  ;; All the actions done under this lock are done in an order
+  ;; that is safe to unwind at any point.
+  (sb-thread::with-recursive-system-spinlock (*specializer-lock*)
+    (call-next-method)))
+
+(defmethod remove-direct-method :around ((specializer specializer) method)
+  ;; All the actions done under this lock are done in an order
+  ;; that is safe to unwind at any point.
+  (sb-thread::with-recursive-system-spinlock (*specializer-lock*)
+    (call-next-method)))
+
 (defmethod add-direct-method ((specializer class) (method method))
-  (with-slots (direct-methods) specializer
-    (setf (car direct-methods) (adjoin method (car direct-methods))     ;PUSH
-          (cdr direct-methods) ()))
+  (let ((cell (slot-value specializer 'direct-methods)))
+    ;; We need to first smash the CDR, because a parallel read may
+    ;; be in progress, and because if an interrupt catches us we
+    ;; need to have a consistent state.
+    (setf (cdr cell) ()
+          (car cell) (adjoin method (car cell) :test #'eq)))
   method)
+
 (defmethod remove-direct-method ((specializer class) (method method))
-  (with-slots (direct-methods) specializer
-    (setf (car direct-methods) (remove method (car direct-methods))
-          (cdr direct-methods) ()))
+  (let ((cell (slot-value specializer 'direct-methods)))
+    ;; We need to first smash the CDR, because a parallel read may
+    ;; be in progress, and because if an interrupt catches us we
+    ;; need to have a consistent state.
+    (setf (cdr cell) ()
+          (car cell) (remove method (car cell))))
   method)
 
 (defmethod specializer-direct-methods ((specializer class))
@@ -189,20 +237,26 @@
     (car direct-methods)))
 
 (defmethod specializer-direct-generic-functions ((specializer class))
-  (with-slots (direct-methods) specializer
-    (or (cdr direct-methods)
-        (setf (cdr direct-methods)
-              (let (collect)
-                (dolist (m (car direct-methods))
-                  ;; the old PCL code used COLLECTING-ONCE which used
-                  ;; #'EQ to check for newness
-                  (pushnew (method-generic-function m) collect :test #'eq))
-                (nreverse collect))))))
+  (let ((cell (slot-value specializer 'direct-methods)))
+    ;; If an ADD/REMOVE-METHOD is in progress, no matter: either
+    ;; we behave as if we got just first or just after -- it's just
+    ;; for update that we need to lock.
+    (or (cdr cell)
+        (sb-thread::with-spinlock (*specializer-lock*)
+          (setf (cdr cell)
+                (let (collect)
+                  (dolist (m (car cell))
+                    ;; the old PCL code used COLLECTING-ONCE which used
+                    ;; #'EQ to check for newness
+                    (pushnew (method-generic-function m) collect :test #'eq))
+                  (nreverse collect)))))))
 
 ;;; This hash table is used to store the direct methods and direct generic
 ;;; functions of EQL specializers. Each value in the table is the cons.
-(defvar *eql-specializer-methods* (make-hash-table :test 'eql))
-(defvar *class-eq-specializer-methods* (make-hash-table :test 'eq))
+;;;
+;;; These tables are shared between threads, so they need to be synchronized.
+(defvar *eql-specializer-methods* (make-hash-table :test 'eql :synchronized t))
+(defvar *class-eq-specializer-methods* (make-hash-table :test 'eq :synchronized t))
 
 (defmethod specializer-method-table ((specializer eql-specializer))
   *eql-specializer-methods*)
@@ -216,11 +270,13 @@
          (table (specializer-method-table specializer))
          (entry (gethash object table)))
     (unless entry
-      (setq entry
-            (setf (gethash object table)
-                  (cons nil nil))))
-    (setf (car entry) (adjoin method (car entry))
-          (cdr entry) ())
+      (setf entry
+            (setf (gethash object table) (cons nil nil))))
+    ;; We need to first smash the CDR, because a parallel read may
+    ;; be in progress, and because if an interrupt catches us we
+    ;; need to have a consistent state.
+    (setf (cdr entry) ()
+          (car entry) (adjoin method (car entry) :test #'eq))
     method))
 
 (defmethod remove-direct-method ((specializer specializer-with-object)
@@ -228,8 +284,11 @@
   (let* ((object (specializer-object specializer))
          (entry (gethash object (specializer-method-table specializer))))
     (when entry
-      (setf (car entry) (remove method (car entry))
-            (cdr entry) ()))
+      ;; We need to first smash the CDR, because a parallel read may
+      ;; be in progress, and because if an interrupt catches us we
+      ;; need to have a consistent state.
+      (setf (cdr entry) ()
+            (car entry) (remove method (car entry))))
     method))
 
 (defmethod specializer-direct-methods ((specializer specializer-with-object))
@@ -242,11 +301,12 @@
          (entry (gethash object (specializer-method-table specializer))))
     (when entry
       (or (cdr entry)
-          (setf (cdr entry)
-                (let (collect)
-                  (dolist (m (car entry))
-                    (pushnew (method-generic-function m) collect :test #'eq))
-                  (nreverse collect)))))))
+          (sb-thread::with-spinlock (*specializer-lock*)
+            (setf (cdr entry)
+                  (let (collect)
+                    (dolist (m (car entry))
+                      (pushnew (method-generic-function m) collect :test #'eq))
+                    (nreverse collect))))))))
 
 (defun map-specializers (function)
   (map-all-classes (lambda (class)
@@ -286,83 +346,94 @@
         (constantly (make-member-type :members (list (specializer-object specl))))))
 
 (defun real-load-defclass (name metaclass-name supers slots other
-                           readers writers slot-names source-location)
+                           readers writers slot-names source-location safe-p)
   (with-single-package-locked-error (:symbol name "defining ~S as a class")
     (%compiler-defclass name readers writers slot-names)
     (let ((res (apply #'ensure-class name :metaclass metaclass-name
                       :direct-superclasses supers
                       :direct-slots slots
                       :definition-source source-location
+                      'safe-p safe-p
                       other)))
       res)))
 
 (setf (gdefinition 'load-defclass) #'real-load-defclass)
 
 (defun ensure-class (name &rest args)
-  (apply #'ensure-class-using-class
-         (let ((class (find-class name nil)))
-           (when (and class (eq name (class-name class)))
-             ;; NAME is the proper name of CLASS, so redefine it
-             class))
-         name
-         args))
+  (with-world-lock ()
+    (apply #'ensure-class-using-class
+           (let ((class (find-class name nil)))
+             (when (and class (eq name (class-name class)))
+               ;; NAME is the proper name of CLASS, so redefine it
+               class))
+           name
+           args)))
 
 (defmethod ensure-class-using-class ((class null) name &rest args &key)
-  (multiple-value-bind (meta initargs)
-      (ensure-class-values class args)
-    #+nil
-    (set-class-type-translation (class-prototype meta) name)
-    (setf class (apply #'make-instance meta :name name initargs))
-    (without-package-locks
-      (setf (find-class name) class))
-    (set-class-type-translation class name)
-    class))
+  (with-world-lock ()
+    (multiple-value-bind (meta initargs)
+        (frob-ensure-class-args args)
+      (setf class (apply #'make-instance meta :name name initargs))
+      (without-package-locks
+        (setf (find-class name) class))))
+  ;; After boot (SETF FIND-CLASS) does this.
+  (unless (eq **boot-state** 'complete)
+    (%set-class-type-translation class name))
+  class)
 
 (defmethod ensure-class-using-class ((class pcl-class) name &rest args &key)
-  (multiple-value-bind (meta initargs)
-      (ensure-class-values class args)
-    (unless (eq (class-of class) meta)
-      (apply #'change-class class meta initargs))
-    (apply #'reinitialize-instance class initargs)
-    (without-package-locks
-      (setf (find-class name) class))
-    (set-class-type-translation class name)
-    class))
-
-(defun fix-super (s)
-  (cond ((classp s) s)
-        ((not (legal-class-name-p s))
-         (error "~S is not a class or a legal class name." s))
-        (t
-         (or (find-class s nil)
-             (ensure-class s :metaclass 'forward-referenced-class)))))
+  (with-world-lock ()
+    (multiple-value-bind (meta initargs)
+        (frob-ensure-class-args args)
+      (unless (eq (class-of class) meta)
+        (apply #'change-class class meta initargs))
+      (apply #'reinitialize-instance class initargs)
+      (without-package-locks
+        (setf (find-class name) class))))
+  ;; After boot (SETF FIND-CLASS) does this.
+  (unless (eq **boot-state** 'complete)
+    (%set-class-type-translation class name))
+  class)
 
-(defun ensure-class-values (class initargs)
+(defun frob-ensure-class-args (args)
   (let (metaclass metaclassp reversed-plist)
-    (doplist (key val) initargs
-      (cond ((eq key :metaclass)
-             (setf metaclass val
-                   metaclassp key))
-            (t
-             (when (eq key :direct-superclasses)
-               (setf val (mapcar #'fix-super val)))
-             (setf reversed-plist (list* val key reversed-plist)))))
-    (values (cond (metaclassp
-                   (if (classp metaclass)
-                       metaclass
-                       (find-class metaclass)))
-                  ((or (null class) (forward-referenced-class-p class))
-                   *the-class-standard-class*)
-                  (t
-                   (class-of class)))
-            (nreverse reversed-plist))))
-
+    (flet ((frob-superclass (s)
+             (cond
+               ((classp s) s)
+               ((legal-class-name-p s)
+                (or (find-class s nil)
+                    (ensure-class s :metaclass 'forward-referenced-class)))
+               (t (error "Not a class or a legal class name: ~S." s)))))
+      (doplist (key val) args
+        (cond ((eq key :metaclass)
+               (unless metaclassp
+                 (setf metaclass val metaclassp key)))
+              (t
+               (when (eq key :direct-superclasses)
+                 (setf val (mapcar #'frob-superclass val)))
+               (setf reversed-plist (list* val key reversed-plist)))))
+      (values (cond (metaclassp
+                     (if (classp metaclass)
+                         metaclass
+                         (find-class metaclass)))
+                    (t *the-class-standard-class*))
+              (nreverse reversed-plist)))))
+
+(defun call-initfun (fun slotd safe)
+  (declare (function fun))
+  (let ((value (funcall fun)))
+    (when safe
+      (let ((typecheck (slot-definition-type-check-function slotd)))
+        (when typecheck
+          (funcall (the function typecheck) value))))
+    value))
 
 (defmethod shared-initialize :after
     ((class std-class) slot-names &key
      (direct-superclasses nil direct-superclasses-p)
      (direct-slots nil direct-slots-p)
-     (direct-default-initargs nil direct-default-initargs-p))
+     (direct-default-initargs nil direct-default-initargs-p)
+     definition-source)
   (cond (direct-superclasses-p
          (setq direct-superclasses
                (or direct-superclasses
@@ -375,8 +446,8 @@
                      super-class of the class ~S, ~
                      but the meta-classes ~S and ~S are incompatible.  ~
                      Define a method for ~S to avoid this error.~@:>"
-                     superclass class (class-of superclass) (class-of class)
-                     'validate-superclass)))
+                    superclass class (class-of superclass) (class-of class)
+                    'validate-superclass)))
          (setf (slot-value class 'direct-superclasses) direct-superclasses))
         (t
          (setq direct-superclasses (slot-value class 'direct-superclasses))))
@@ -393,6 +464,7 @@
             (plist-value class 'direct-default-initargs)))
   (setf (plist-value class 'class-slot-cells)
         (let ((old-class-slot-cells (plist-value class 'class-slot-cells))
+              (safe (safe-p class))
               (collect '()))
           (dolist (dslotd direct-slots)
             (when (eq :class (slot-definition-allocation dslotd))
@@ -401,37 +473,21 @@
                      (old (assoc name old-class-slot-cells)))
                 (if (or (not old)
                         (eq t slot-names)
-                        (member name slot-names))
+                        (member name slot-names :test #'eq))
                     (let* ((initfunction (slot-definition-initfunction dslotd))
-                           (value (if initfunction
-                                      (funcall initfunction)
-                                      +slot-unbound+)))
+                           (value
+                            (if initfunction
+                                (call-initfun initfunction dslotd safe)
+                                +slot-unbound+)))
                       (push (cons name value) collect))
                     (push old collect)))))
           (nreverse collect)))
   (add-direct-subclasses class direct-superclasses)
-  (update-class class nil)
-  (do* ((slots (slot-value class 'slots) (cdr slots))
-        (dupes nil))
-       ((null slots) (when dupes
-                       (style-warn
-                        ;; FIXME: the indentation request ("~4I")
-                        ;; below appears not to do anything.  Finding
-                        ;; out why would be nice.  -- CSR, 2003-04-24
-                        "~@<slot names with the same SYMBOL-NAME but ~
-                         different SYMBOL-PACKAGE (possible package problem) ~
-                         for class ~S:~@:_~4I~<~@{~S~^~:@_~}~:>~@:>"
-                        class
-                        dupes)))
-    (let* ((slot (car slots))
-           (oslots (remove (slot-definition-name slot) (cdr slots)
-                           :test #'string/= :key #'slot-definition-name)))
-      (when oslots
-        (pushnew (cons (slot-definition-name slot)
-                       (mapcar #'slot-definition-name oslots))
-                 dupes
-                 :test #'string= :key #'car))))
-  (add-slot-accessors class direct-slots)
+  (if (class-finalized-p class)
+      ;; required by AMOP, "Reinitialization of Class Metaobjects"
+      (finalize-inheritance class)
+      (update-class class nil))
+  (add-slot-accessors class direct-slots definition-source)
   (make-preliminary-layout class))
 
 (defmethod shared-initialize :after ((class forward-referenced-class)
@@ -447,23 +503,25 @@
   (flet ((compute-preliminary-cpl (root)
            (let ((*allow-forward-referenced-classes-in-cpl-p* t))
              (compute-class-precedence-list root))))
-    (without-package-locks
-     (unless (class-finalized-p class)
-       (let ((name (class-name class)))
-         ;; KLUDGE: This is fairly horrible.  We need to make a
-         ;; full-fledged CLASSOID here, not just tell the compiler that
-         ;; some class is forthcoming, because there are legitimate
-         ;; questions one can ask of the type system, implemented in
-         ;; terms of CLASSOIDs, involving forward-referenced classes. So.
-         (let ((layout (make-wrapper 0 class)))
-           (setf (slot-value class 'wrapper) layout)
-           (let ((cpl (compute-preliminary-cpl class)))
-             (setf (layout-inherits layout)
-                   (order-layout-inherits
-                    (map 'simple-vector #'class-wrapper
-                         (reverse (rest cpl))))))
-           (register-layout layout :invalidate t))))
-     (mapc #'make-preliminary-layout (class-direct-subclasses class)))))
+    (with-world-lock ()
+      (without-package-locks
+        (unless (class-finalized-p class)
+          (let ((name (class-name class)))
+            ;; KLUDGE: This is fairly horrible.  We need to make a
+            ;; full-fledged CLASSOID here, not just tell the compiler that
+            ;; some class is forthcoming, because there are legitimate
+            ;; questions one can ask of the type system, implemented in
+            ;; terms of CLASSOIDs, involving forward-referenced classes. So.
+            (let ((layout (make-wrapper 0 class)))
+              (setf (slot-value class 'wrapper) layout)
+              (let ((cpl (compute-preliminary-cpl class)))
+                (setf (layout-inherits layout)
+                      (order-layout-inherits
+                       (map 'simple-vector #'class-wrapper
+                            (reverse (rest cpl))))))
+              (register-layout layout :invalidate t)
+              (%set-class-type-translation class (layout-classoid layout)))))
+        (mapc #'make-preliminary-layout (class-direct-subclasses class))))))
 
 
 (defmethod shared-initialize :before ((class class) slot-names &key name)
@@ -504,7 +562,7 @@
 (defmethod shared-initialize :after ((class condition-class) slot-names
                                      &key direct-slots direct-superclasses)
   (declare (ignore slot-names))
-  (let ((classoid (find-classoid (class-name class))))
+  (let ((classoid (find-classoid (slot-value class 'name))))
     (with-slots (wrapper %class-precedence-list cpl-available-p
                          prototype (direct-supers direct-superclasses))
         class
@@ -518,7 +576,9 @@
       (setq %class-precedence-list (compute-class-precedence-list class))
       (setq cpl-available-p t)
       (add-direct-subclasses class direct-superclasses)
-      (setf (slot-value class 'slots) (compute-slots class))))
+      (let ((slots (compute-slots class)))
+        (setf (slot-value class 'slots) slots)
+        (setf (layout-slot-table wrapper) (make-slot-table class slots)))))
   ;; Comment from Gerd's PCL, 2003-05-15:
   ;;
   ;; We don't ADD-SLOT-ACCESSORS here because we don't want to
@@ -532,7 +592,7 @@
   ;; remove slot accessors but never put them back.  I've added a
   ;; REINITIALIZE-INSTANCE :AFTER (CONDITION-CLASS) method, but what
   ;; was meant to happen?  -- CSR, 2005-11-18
-  (update-pv-table-cache-info class))
+  )
 
 (defmethod direct-slot-definition-class ((class condition-class)
                                          &rest initargs)
@@ -579,7 +639,7 @@
 
 (defmethod compute-slots :around ((class condition-class))
   (let ((eslotds (call-next-method)))
-    (mapc #'initialize-internal-slot-functions eslotds)
+    (mapc #'finalize-internal-slot-functions eslotds)
     eslotds))
 
 (defmethod shared-initialize :after
@@ -592,72 +652,84 @@
 (defun make-structure-class-defstruct-form (name direct-slots include)
   (let* ((conc-name (format-symbol *package* "~S structure class " name))
          (constructor (format-symbol *package* "~Aconstructor" conc-name))
-         (defstruct `(defstruct (,name
-                                 ,@(when include
-                                         `((:include ,(class-name include))))
-                                 (:predicate nil)
-                                 (:conc-name ,conc-name)
-                                 (:constructor ,constructor ())
-                                 (:copier nil))
-                      ,@(mapcar (lambda (slot)
-                                  `(,(slot-definition-name slot)
-                                    +slot-unbound+))
-                                direct-slots)))
-         (reader-names (mapcar (lambda (slotd)
-                                 (list 'slot-accessor name
-                                       (slot-definition-name slotd)
-                                       'reader))
-                               direct-slots))
-         (writer-names (mapcar (lambda (slotd)
-                                 (list 'slot-accessor name
-                                       (slot-definition-name slotd)
-                                       'writer))
-                               direct-slots))
-         (readers-init
-           (mapcar (lambda (slotd reader-name)
-                     (let ((accessor
+         (included-name (class-name include))
+         (included-slots
+          (when include
+            (mapcar #'dsd-name (dd-slots (find-defstruct-description included-name)))))
+         (old-slots nil)
+         (new-slots nil)
+         (reader-names nil)
+         (writer-names nil))
+    (dolist (slotd (reverse direct-slots))
+      (let* ((slot-name (slot-definition-name slotd))
+             (initform (slot-definition-initform slotd))
+             (type (slot-definition-type slotd))
+             (desc `(,slot-name ,initform :type ,type)))
+        (push `(slot-accessor ,name ,slot-name reader)
+              reader-names)
+        (push `(slot-accessor ,name ,slot-name writer)
+              writer-names)
+        (if (member slot-name included-slots :test #'eq)
+            (push desc old-slots)
+            (push desc new-slots))))
+    (let* ((defstruct `(defstruct (,name
+                                    ,@(when include
+                                            `((:include ,included-name
+                                                        ,@old-slots)))
+                                    (:constructor ,constructor ())
+                                    (:predicate nil)
+                                    (:conc-name ,conc-name)
+                                    (:copier nil))
+                         ,@new-slots))
+           (readers-init
+            (mapcar (lambda (slotd reader-name)
+                      (let ((accessor
                              (slot-definition-defstruct-accessor-symbol
                               slotd)))
-                       `(defun ,reader-name (obj)
-                         (declare (type ,name obj))
-                         (,accessor obj))))
-                   direct-slots reader-names))
-         (writers-init
-           (mapcar (lambda (slotd writer-name)
-                     (let ((accessor
+                        `(defun ,reader-name (obj)
+                           (declare (type ,name obj))
+                           (,accessor obj))))
+                    direct-slots reader-names))
+           (writers-init
+            (mapcar (lambda (slotd writer-name)
+                      (let ((accessor
                              (slot-definition-defstruct-accessor-symbol
                               slotd)))
-                       `(defun ,writer-name (nv obj)
-                         (declare (type ,name obj))
-                         (setf (,accessor obj) nv))))
-                   direct-slots writer-names))
-         (defstruct-form
-             `(progn
+                        `(defun ,writer-name (nv obj)
+                           (declare (type ,name obj))
+                           (setf (,accessor obj) nv))))
+                    direct-slots writer-names))
+           (defstruct-form
+            `(progn
                ,defstruct
                ,@readers-init ,@writers-init
                (cons nil nil))))
-    (values defstruct-form constructor reader-names writer-names)))
+      (values defstruct-form constructor reader-names writer-names))))
 
-(defun make-defstruct-allocation-function (class)
-  (let ((dd (get-structure-dd (class-name class))))
-    (lambda ()
-      (sb-kernel::%make-instance-with-layout
-       (sb-kernel::compiler-layout-or-lose (dd-name dd))))))
+(defun make-defstruct-allocation-function (name)
+  ;; FIXME: Why don't we go class->layout->info == dd
+  (let ((dd (find-defstruct-description name)))
+    (ecase (dd-type dd)
+      (structure
+       (%make-structure-instance-allocator dd nil))
+      (funcallable-structure
+       (%make-funcallable-structure-instance-allocator dd nil)))))
 
 (defmethod shared-initialize :after
     ((class structure-class) slot-names &key
      (direct-superclasses nil direct-superclasses-p)
      (direct-slots nil direct-slots-p)
-     direct-default-initargs)
+     direct-default-initargs
+     definition-source)
   (declare (ignore slot-names direct-default-initargs))
   (if direct-superclasses-p
       (setf (slot-value class 'direct-superclasses)
             (or direct-superclasses
                 (setq direct-superclasses
-                      (and (not (eq (class-name class) 'structure-object))
+                      (and (not (eq (slot-value class 'name) 'structure-object))
                            (list *the-class-structure-object*)))))
       (setq direct-superclasses (slot-value class 'direct-superclasses)))
-  (let* ((name (class-name class))
+  (let* ((name (slot-value class 'name))
          (from-defclass-p (slot-value class 'from-defclass-p))
          (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
     (if direct-slots-p
@@ -692,18 +764,22 @@
             (setf (slot-value class 'defstruct-form) defstruct-form)
             (setf (slot-value class 'defstruct-constructor) constructor)))
         (setf (slot-value class 'defstruct-constructor)
-              (make-defstruct-allocation-function class)))
+              ;; KLUDGE: not class; in fixup.lisp, can't access slots
+              ;; outside methods yet.
+              (make-defstruct-allocation-function name)))
     (add-direct-subclasses class direct-superclasses)
     (setf (slot-value class '%class-precedence-list)
           (compute-class-precedence-list class))
     (setf (slot-value class 'cpl-available-p) t)
-    (setf (slot-value class 'slots) (compute-slots class))
-    (let ((lclass (find-classoid (class-name class))))
-      (setf (classoid-pcl-class lclass) class)
-      (setf (slot-value class 'wrapper) (classoid-layout lclass)))
+    (let ((slots (compute-slots class)))
+      (setf (slot-value class 'slots) slots)
+      (let* ((lclass (find-classoid (slot-value class 'name)))
+             (layout (classoid-layout lclass)))
+        (setf (classoid-pcl-class lclass) class)
+        (setf (slot-value class 'wrapper) layout)
+        (setf (layout-slot-table layout) (make-slot-table class slots))))
     (setf (slot-value class 'finalized-p) t)
-    (update-pv-table-cache-info class)
-    (add-slot-accessors class direct-slots)))
+    (add-slot-accessors class direct-slots definition-source)))
 
 (defmethod direct-slot-definition-class ((class structure-class) &rest initargs)
   (declare (ignore initargs))
@@ -712,40 +788,37 @@
 (defmethod finalize-inheritance ((class structure-class))
   nil) ; always finalized
 
-(defun add-slot-accessors (class dslotds)
-  (fix-slot-accessors class dslotds 'add))
+(defun add-slot-accessors (class dslotds &optional source-location)
+  (fix-slot-accessors class dslotds 'add source-location))
 
 (defun remove-slot-accessors (class dslotds)
   (fix-slot-accessors class dslotds 'remove))
 
-(defun fix-slot-accessors (class dslotds add/remove)
-  (flet ((fix (gfspec name r/w)
+(defun fix-slot-accessors (class dslotds add/remove &optional source-location)
+  (flet ((fix (gfspec name r/w doc)
            (let ((gf (cond ((eq add/remove 'add)
-                            (if (fboundp gfspec)
-                                (without-package-locks
-                                  (ensure-generic-function gfspec))
+                            (or (find-generic-function gfspec nil)
                                 (ensure-generic-function
                                  gfspec :lambda-list (case r/w
                                                        (r '(object))
                                                        (w '(new-value object))))))
-                           ((generic-function-p (and (fboundp gfspec)
-                                                     (fdefinition gfspec)))
-                            (without-package-locks
-                              (ensure-generic-function gfspec))))))
+                           (t
+                            (find-generic-function gfspec nil)))))
              (when gf
                (case r/w
                  (r (if (eq add/remove 'add)
-                        (add-reader-method class gf name)
+                        (add-reader-method class gf name doc source-location)
                         (remove-reader-method class gf)))
                  (w (if (eq add/remove 'add)
-                        (add-writer-method class gf name)
+                        (add-writer-method class gf name doc source-location)
                         (remove-writer-method class gf))))))))
     (dolist (dslotd dslotds)
-      (let ((slot-name (slot-definition-name dslotd)))
+      (let ((slot-name (slot-definition-name dslotd))
+            (slot-doc (%slot-definition-documentation dslotd)))
         (dolist (r (slot-definition-readers dslotd))
-          (fix r slot-name 'r))
+          (fix r slot-name 'r slot-doc))
         (dolist (w (slot-definition-writers dslotd))
-          (fix w slot-name 'w))))))
+          (fix w slot-name 'w slot-doc))))))
 
 (defun add-direct-subclasses (class supers)
   (dolist (super supers)
@@ -775,16 +848,17 @@
 ;;; or reinitialized. The class may or may not be finalized.
 (defun update-class (class finalizep)
   (without-package-locks
-   (when (or finalizep (class-finalized-p class))
-     (update-cpl class (compute-class-precedence-list class))
-     ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
-     ;; class.
-     (update-slots class (compute-slots class))
-     (update-gfs-of-class class)
-     (update-initargs class (compute-default-initargs class))
-     (update-ctors 'finalize-inheritance :class class))
-   (dolist (sub (class-direct-subclasses class))
-     (update-class sub nil))))
+    (with-world-lock ()
+      (when (or finalizep (class-finalized-p class))
+        (%update-cpl class (compute-class-precedence-list class))
+        ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
+        ;; class.
+        (%update-slots class (compute-slots class))
+        (update-gfs-of-class class)
+        (setf (plist-value class 'default-initargs) (compute-default-initargs class))
+        (update-ctors 'finalize-inheritance :class class))
+      (dolist (sub (class-direct-subclasses class))
+        (update-class sub nil)))))
 
 (define-condition cpl-protocol-violation (reference-condition error)
   ((class :initarg :class :reader cpl-protocol-violation-class)
@@ -802,7 +876,7 @@
              (find-class 'function)
              (cpl-protocol-violation-cpl c)))))
 
-(defun update-cpl (class cpl)
+(defun %update-cpl (class cpl)
   (when (eq (class-of class) *the-class-standard-class*)
     (when (find (find-class 'function) cpl)
       (error 'cpl-protocol-violation :class class :cpl cpl)))
@@ -816,11 +890,11 @@
                                      :key #'slot-definition-allocation)
                        (return nil))))
         ;; comment from the old CMU CL sources:
-        ;;   Need to have the cpl setup before update-lisp-class-layout
+        ;;   Need to have the cpl setup before %update-lisp-class-layout
         ;;   is called on CMU CL.
         (setf (slot-value class '%class-precedence-list) cpl)
         (setf (slot-value class 'cpl-available-p) t)
-        (force-cache-flushes class))
+        (%force-cache-flushes class))
       (progn
         (setf (slot-value class '%class-precedence-list) cpl)
         (setf (slot-value class 'cpl-available-p) t)))
@@ -830,13 +904,13 @@
   (when cpl
     (let ((first (car cpl)))
       (dolist (c (cdr cpl))
-        (pushnew c (slot-value first 'can-precede-list))))
+        (pushnew c (slot-value first 'can-precede-list) :test #'eq)))
     (update-class-can-precede-p (cdr cpl))))
 
 (defun class-can-precede-p (class1 class2)
-  (member class2 (class-can-precede-list class1)))
+  (member class2 (class-can-precede-list class1) :test #'eq))
 
-(defun update-slots (class eslotds)
+(defun %update-slots (class eslotds)
   (let ((instance-slots ())
         (class-slots    ()))
     (dolist (eslotd eslotds)
@@ -875,17 +949,34 @@
                    (make-instances-obsolete class)
                    (class-wrapper class)))))
 
-      (with-slots (wrapper slots) class
-        (update-lisp-class-layout class nwrapper)
-        (setf slots eslotds
-              (wrapper-instance-slots-layout nwrapper) nlayout
-              (wrapper-class-slots nwrapper) nwrapper-class-slots
-              (wrapper-no-of-instance-slots nwrapper) nslots
-              wrapper nwrapper))
+      (%update-lisp-class-layout class nwrapper)
+      (setf (slot-value class 'slots) eslotds
+            (wrapper-slot-table nwrapper) (make-slot-table class eslotds)
+            (wrapper-instance-slots-layout nwrapper) nlayout
+            (wrapper-class-slots nwrapper) nwrapper-class-slots
+            (wrapper-length nwrapper) nslots
+            (slot-value class 'wrapper) nwrapper)
+      (do* ((slots (slot-value class 'slots) (cdr slots))
+            (dupes nil))
+           ((null slots)
+            (when dupes
+              (style-warn
+               "~@<slot names with the same SYMBOL-NAME but ~
+                  different SYMBOL-PACKAGE (possible package problem) ~
+                  for class ~S:~4I~@:_~<~@{~/sb-impl::print-symbol-with-prefix/~^~:@_~}~:>~@:>"
+               class dupes)))
+        (let* ((slot (car slots))
+               (oslots (remove (slot-definition-name slot) (cdr slots)
+                               :test #'string/=
+                               :key #'slot-definition-name)))
+          (when oslots
+            (pushnew (cons (slot-definition-name slot)
+                           (mapcar #'slot-definition-name oslots))
+                     dupes
+                     :test #'string= :key #'car))))
       (setf (slot-value class 'finalized-p) t)
       (unless (eq owrapper nwrapper)
-        (update-pv-table-cache-info class)
-        (maybe-update-standard-class-locations class)))))
+        (maybe-update-standard-slot-locations class)))))
 
 (defun compute-class-slots (eslotds)
   (let (collect)
@@ -896,12 +987,21 @@
         (aver cell)
         (push cell collect)))))
 
+(defun update-gf-dfun (class gf)
+  (let ((*new-class* class)
+        (arg-info (gf-arg-info gf)))
+    (cond
+      ((special-case-for-compute-discriminating-function-p gf))
+      ((gf-precompute-dfun-and-emf-p arg-info)
+       (multiple-value-bind (dfun cache info) (make-final-dfun-internal gf)
+         (update-dfun gf dfun cache info))))))
+
 (defun update-gfs-of-class (class)
   (when (and (class-finalized-p class)
              (let ((cpl (class-precedence-list class)))
-               (or (member *the-class-slot-class* cpl)
+               (or (member *the-class-slot-class* cpl :test #'eq)
                    (member *the-class-standard-effective-slot-definition*
-                           cpl))))
+                           cpl :test #'eq))))
     (let ((gf-table (make-hash-table :test 'eq)))
       (labels ((collect-gfs (class)
                  (dolist (gf (specializer-direct-generic-functions class))
@@ -912,9 +1012,6 @@
                    (declare (ignore ignore))
                    (update-gf-dfun class gf))
                  gf-table)))))
-
-(defun update-initargs (class inits)
-  (setf (plist-value class 'default-initargs) inits))
 
 (defmethod compute-default-initargs ((class slot-class))
   (let ((initargs (loop for c in (class-precedence-list class)
@@ -966,7 +1063,8 @@
   (std-compute-slots class))
 
 (defun std-compute-slots-around (class eslotds)
-  (let ((location -1))
+  (let ((location -1)
+        (safe (safe-p class)))
     (dolist (eslotd eslotds eslotds)
       (setf (slot-definition-location eslotd)
             (case (slot-definition-allocation eslotd)
@@ -990,10 +1088,12 @@
                                   c))))
                  (aver (consp cell))
                  (if (eq +slot-unbound+ (cdr cell))
-                     ;; We may have inherited an initfunction
+                     ;; We may have inherited an initfunction FIXME: Is this
+                     ;; really right? Is the initialization in
+                     ;; SHARED-INITIALIZE (STD-CLASS) not enough?
                      (let ((initfun (slot-definition-initfunction eslotd)))
                        (if initfun
-                           (rplacd cell (funcall initfun))
+                           (rplacd cell (call-initfun initfun eslotd safe))
                            cell))
                      cell)))))
       (unless (slot-definition-class eslotd)
@@ -1019,7 +1119,7 @@
 
 (defmethod compute-slots :around ((class structure-class))
   (let ((eslotds (call-next-method)))
-    (mapc #'initialize-internal-slot-functions eslotds)
+    (mapc #'finalize-internal-slot-functions eslotds)
     eslotds))
 
 (defmethod compute-effective-slot-definition ((class slot-class) name dslotds)
@@ -1045,6 +1145,7 @@
          (allocation nil)
          (allocation-class nil)
          (type t)
+         (type-check-function nil)
          (documentation nil)
          (documentationp nil)
          (namep  nil)
@@ -1057,19 +1158,29 @@
           (setq name (slot-definition-name slotd)
                 namep t))
         (unless initp
-          (when (slot-definition-initfunction slotd)
+          (awhen (slot-definition-initfunction slotd)
             (setq initform (slot-definition-initform slotd)
-                  initfunction (slot-definition-initfunction slotd)
+                  initfunction it
                   initp t)))
         (unless documentationp
-          (when (%slot-definition-documentation slotd)
-            (setq documentation (%slot-definition-documentation slotd)
+          (awhen (%slot-definition-documentation slotd)
+            (setq documentation it
                   documentationp t)))
         (unless allocp
           (setq allocation (slot-definition-allocation slotd)
                 allocation-class (slot-definition-class slotd)
                 allocp t))
         (setq initargs (append (slot-definition-initargs slotd) initargs))
+        (let ((fun (slot-definition-type-check-function slotd)))
+          (when fun
+            (setf type-check-function
+                  (if type-check-function
+                      (let ((old-function type-check-function))
+                        (declare (function old-function fun))
+                        (lambda (value)
+                          (funcall old-function value)
+                          (funcall fun value)))
+                      fun))))
         (let ((slotd-type (slot-definition-type slotd)))
           (setq type (cond
                        ((eq type t) slotd-type)
@@ -1086,6 +1197,7 @@
           :allocation allocation
           :allocation-class allocation-class
           :type type
+          'type-check-function type-check-function
           :class class
           :documentation documentation)))
 
@@ -1107,39 +1219,47 @@
   (declare (ignore direct-slot initargs))
   (find-class 'standard-reader-method))
 
-(defmethod add-reader-method ((class slot-class) generic-function slot-name)
+(defmethod add-reader-method ((class slot-class) generic-function slot-name slot-documentation source-location)
   (add-method generic-function
               (make-a-method 'standard-reader-method
                              ()
                              (list (or (class-name class) 'object))
                              (list class)
                              (make-reader-method-function class slot-name)
-                             "automatically generated reader method"
-                             slot-name)))
+                             (or slot-documentation "automatically generated reader method")
+                             :slot-name slot-name
+                             :object-class class
+                             :method-class-function #'reader-method-class
+                             :definition-source source-location)))
 
 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
   (declare (ignore direct-slot initargs))
   (find-class 'standard-writer-method))
 
-(defmethod add-writer-method ((class slot-class) generic-function slot-name)
+(defmethod add-writer-method ((class slot-class) generic-function slot-name slot-documentation source-location)
   (add-method generic-function
               (make-a-method 'standard-writer-method
                              ()
                              (list 'new-value (or (class-name class) 'object))
                              (list *the-class-t* class)
                              (make-writer-method-function class slot-name)
-                             "automatically generated writer method"
-                             slot-name)))
+                             (or slot-documentation "automatically generated writer method")
+                             :slot-name slot-name
+                             :object-class class
+                             :method-class-function #'writer-method-class
+                             :definition-source source-location)))
 
-(defmethod add-boundp-method ((class slot-class) generic-function slot-name)
+(defmethod add-boundp-method ((class slot-class) generic-function slot-name slot-documentation source-location)
   (add-method generic-function
-              (make-a-method 'standard-boundp-method
+              (make-a-method (constantly (find-class 'standard-boundp-method))
+                             class
                              ()
                              (list (or (class-name class) 'object))
                              (list class)
                              (make-boundp-method-function class slot-name)
-                             "automatically generated boundp method"
-                             slot-name)))
+                             (or slot-documentation "automatically generated boundp method")
+                             :slot-name slot-name
+                             :definition-source source-location)))
 
 (defmethod remove-reader-method ((class slot-class) generic-function)
   (let ((method (get-method generic-function () (list class) nil)))
@@ -1154,9 +1274,10 @@
   (let ((method (get-method generic-function () (list class) nil)))
     (when method (remove-method generic-function method))))
 
-;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITE-METHOD function are NOT
-;;; part of the standard protocol. They are however useful, PCL makes
-;;; use of them internally and documents them for PCL users.
+;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITER-METHOD-FUNCTION
+;;; function are NOT part of the standard protocol. They are however
+;;; useful; PCL makes use of them internally and documents them for
+;;; PCL users.  (FIXME: but SBCL certainly doesn't)
 ;;;
 ;;; *** This needs work to make type testing by the writer functions which
 ;;; *** do type testing faster. The idea would be to have one constructor
@@ -1168,13 +1289,13 @@
 ;;; *** defined for this metaclass a chance to run.
 
 (defmethod make-reader-method-function ((class slot-class) slot-name)
-  (make-std-reader-method-function (class-name class) slot-name))
+  (make-std-reader-method-function class slot-name))
 
 (defmethod make-writer-method-function ((class slot-class) slot-name)
-  (make-std-writer-method-function (class-name class) slot-name))
+  (make-std-writer-method-function class slot-name))
 
 (defmethod make-boundp-method-function ((class slot-class) slot-name)
-  (make-std-boundp-method-function (class-name class) slot-name))
+  (make-std-boundp-method-function class slot-name))
 
 (defmethod compatible-meta-class-change-p (class proto-new-class)
   (eq (class-of class) (class-of proto-new-class)))
@@ -1206,7 +1327,7 @@
 ;;;                    :UNINITIALIZED)))
 ;;;
 ;;; Thanks to Gerd Moellmann for the explanation.  -- CSR, 2002-10-29
-(defun force-cache-flushes (class)
+(defun %force-cache-flushes (class)
   (let* ((owrapper (class-wrapper class)))
     ;; We only need to do something if the wrapper is still valid. If
     ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
@@ -1219,47 +1340,46 @@
               ;; good style.  There has to be a better way!  -- CSR,
               ;; 2002-10-29
               (eq (layout-invalid owrapper) t))
-      (let ((nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
+      (let ((nwrapper (make-wrapper (layout-length owrapper)
                                     class)))
         (setf (wrapper-instance-slots-layout nwrapper)
               (wrapper-instance-slots-layout owrapper))
         (setf (wrapper-class-slots nwrapper)
               (wrapper-class-slots owrapper))
-        (with-pcl-lock
-          (update-lisp-class-layout class nwrapper)
-          (setf (slot-value class 'wrapper) nwrapper)
-          ;; Use :OBSOLETE instead of :FLUSH if any superclass has
-          ;; been obsoleted.
-          (if (find-if (lambda (x)
-                         (and (consp x) (eq :obsolete (car x))))
-                       (layout-inherits owrapper)
-                       :key #'layout-invalid)
-              (invalidate-wrapper owrapper :obsolete nwrapper)
-              (invalidate-wrapper owrapper :flush nwrapper)))))))
-
-(defun flush-cache-trap (owrapper nwrapper instance)
-  (declare (ignore owrapper))
-  (set-wrapper instance nwrapper))
+        (setf (wrapper-slot-table nwrapper)
+              (wrapper-slot-table owrapper))
+        (%update-lisp-class-layout class nwrapper)
+        (setf (slot-value class 'wrapper) nwrapper)
+        ;; Use :OBSOLETE instead of :FLUSH if any superclass has
+        ;; been obsoleted.
+        (if (find-if (lambda (x)
+                       (and (consp x) (eq :obsolete (car x))))
+                     (layout-inherits owrapper)
+                     :key #'layout-invalid)
+            (%invalidate-wrapper owrapper :obsolete nwrapper)
+            (%invalidate-wrapper owrapper :flush nwrapper))))))
 
 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
 ;;; the next access to the instance (as defined in 88-002R) to trap
 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
 (defmethod make-instances-obsolete ((class std-class))
-  (let* ((owrapper (class-wrapper class))
-         (nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
-                                 class)))
-    (unless (class-finalized-p class)
-      (if (class-has-a-forward-referenced-superclass-p class)
-          (return-from make-instances-obsolete class)
-          (update-cpl class (compute-class-precedence-list class))))
-    (setf (wrapper-instance-slots-layout nwrapper)
-          (wrapper-instance-slots-layout owrapper))
-    (setf (wrapper-class-slots nwrapper)
-          (wrapper-class-slots owrapper))
-    (with-pcl-lock
-        (update-lisp-class-layout class nwrapper)
+  (with-world-lock ()
+    (let* ((owrapper (class-wrapper class))
+           (nwrapper (make-wrapper (layout-length owrapper)
+                                   class)))
+      (unless (class-finalized-p class)
+        (if (class-has-a-forward-referenced-superclass-p class)
+            (return-from make-instances-obsolete class)
+            (%update-cpl class (compute-class-precedence-list class))))
+      (setf (wrapper-instance-slots-layout nwrapper)
+            (wrapper-instance-slots-layout owrapper))
+      (setf (wrapper-class-slots nwrapper)
+            (wrapper-class-slots owrapper))
+      (setf (wrapper-slot-table nwrapper)
+            (wrapper-slot-table owrapper))
+      (%update-lisp-class-layout class nwrapper)
       (setf (slot-value class 'wrapper) nwrapper)
-      (invalidate-wrapper owrapper :obsolete nwrapper)
+      (%invalidate-wrapper owrapper :obsolete nwrapper)
       class)))
 
 (defmethod make-instances-obsolete ((class symbol))
@@ -1307,12 +1427,12 @@
              "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
              (type-of (obsolete-structure-datum condition))))))
 
-(defun obsolete-instance-trap (owrapper nwrapper instance)
-  (if (not (pcl-instance-p instance))
+(defun %obsolete-instance-trap (owrapper nwrapper instance)
+  (if (not (layout-for-std-class-p owrapper))
       (if *in-obsolete-instance-trap*
           *the-wrapper-of-structure-object*
-           (let ((*in-obsolete-instance-trap* t))
-             (error 'obsolete-structure :datum instance)))
+          (let ((*in-obsolete-instance-trap* t))
+            (error 'obsolete-structure :datum instance)))
       (let* ((class (wrapper-class* nwrapper))
              (copy (allocate-instance class)) ;??? allocate-instance ???
              (olayout (wrapper-instance-slots-layout owrapper))
@@ -1360,7 +1480,7 @@
                       (assq nlocal oclass-slots))
             (push nlocal added)))
 
-        (swap-wrappers-and-slots instance copy)
+        (%swap-wrappers-and-slots instance copy)
 
         (update-instance-for-redefined-class instance
                                              added
@@ -1368,7 +1488,7 @@
                                              plist)
         nwrapper)))
 
-(defun change-class-internal (instance new-class initargs)
+(defun %change-class (instance new-class initargs)
   (let* ((old-class (class-of instance))
          (copy (allocate-instance new-class))
          (new-wrapper (get-wrapper copy))
@@ -1399,63 +1519,67 @@
 
     ;; Make the copy point to the old instance's storage, and make the
     ;; old instance point to the new storage.
-    (swap-wrappers-and-slots instance copy)
+    (%swap-wrappers-and-slots instance copy)
 
     (apply #'update-instance-for-different-class copy instance initargs)
+
     instance))
 
 (defmethod change-class ((instance standard-object) (new-class standard-class)
                          &rest initargs)
-  (unless (class-finalized-p new-class)
-    (finalize-inheritance new-class))
-  (let ((cpl (class-precedence-list new-class)))
-    (dolist (class cpl)
-      (macrolet
-          ((frob (class-name)
-             `(when (eq class (find-class ',class-name))
-               (error 'metaobject-initialization-violation
-                :format-control "~@<Cannot ~S objects into ~S metaobjects.~@:>"
-                :format-arguments (list 'change-class ',class-name)
-                :references (list '(:amop :initialization ,class-name))))))
-        (frob class)
-        (frob generic-function)
-        (frob method)
-        (frob slot-definition))))
-  (change-class-internal instance new-class initargs))
+  (with-world-lock ()
+    (unless (class-finalized-p new-class)
+      (finalize-inheritance new-class))
+    (let ((cpl (class-precedence-list new-class)))
+      (dolist (class cpl)
+        (macrolet
+            ((frob (class-name)
+               `(when (eq class (find-class ',class-name))
+                  (error 'metaobject-initialization-violation
+                         :format-control "~@<Cannot ~S objects into ~S metaobjects.~@:>"
+                         :format-arguments (list 'change-class ',class-name)
+                         :references (list '(:amop :initialization ,class-name))))))
+          (frob class)
+          (frob generic-function)
+          (frob method)
+          (frob slot-definition))))
+    (%change-class instance new-class initargs)))
 
 (defmethod change-class ((instance forward-referenced-class)
                          (new-class standard-class) &rest initargs)
-  (let ((cpl (class-precedence-list new-class)))
-    (dolist (class cpl
-             (error 'metaobject-initialization-violation
-                    :format-control
-                    "~@<Cannot ~S ~S objects into non-~S objects.~@:>"
-                    :format-arguments
-                    (list 'change-class 'forward-referenced-class 'class)
-                    :references
-                    (list '(:amop :generic-function ensure-class-using-class)
-                          '(:amop :initialization class))))
-      (when (eq class (find-class 'class))
-        (return nil))))
-  (change-class-internal instance new-class initargs))
+  (with-world-lock ()
+    (let ((cpl (class-precedence-list new-class)))
+      (dolist (class cpl
+               (error 'metaobject-initialization-violation
+                      :format-control
+                      "~@<Cannot ~S ~S objects into non-~S objects.~@:>"
+                      :format-arguments
+                      (list 'change-class 'forward-referenced-class 'class)
+                      :references
+                      (list '(:amop :generic-function ensure-class-using-class)
+                            '(:amop :initialization class))))
+        (when (eq class (find-class 'class))
+          (return nil))))
+    (%change-class instance new-class initargs)))
 
 (defmethod change-class ((instance funcallable-standard-object)
                          (new-class funcallable-standard-class)
                          &rest initargs)
-  (let ((cpl (class-precedence-list new-class)))
-    (dolist (class cpl)
-      (macrolet
-          ((frob (class-name)
-             `(when (eq class (find-class ',class-name))
-               (error 'metaobject-initialization-violation
-                :format-control "~@<Cannot ~S objects into ~S metaobjects.~@:>"
-                :format-arguments (list 'change-class ',class-name)
-                :references (list '(:amop :initialization ,class-name))))))
-        (frob class)
-        (frob generic-function)
-        (frob method)
-        (frob slot-definition))))
-  (change-class-internal instance new-class initargs))
+  (with-world-lock ()
+    (let ((cpl (class-precedence-list new-class)))
+      (dolist (class cpl)
+        (macrolet
+            ((frob (class-name)
+               `(when (eq class (find-class ',class-name))
+                  (error 'metaobject-initialization-violation
+                         :format-control "~@<Cannot ~S objects into ~S metaobjects.~@:>"
+                         :format-arguments (list 'change-class ',class-name)
+                         :references (list '(:amop :initialization ,class-name))))))
+          (frob class)
+          (frob generic-function)
+          (frob method)
+          (frob slot-definition))))
+    (%change-class instance new-class initargs)))
 
 (defmethod change-class ((instance standard-object)
                          (new-class funcallable-standard-class)
@@ -1510,7 +1634,11 @@
       ;; FILE-STREAM and STRING-STREAM (as they have the same
       ;; layout-depthoid).  Is there any way we can provide a useful
       ;; error message?  -- CSR, 2005-05-03
-      (eq s *the-class-file-stream*) (eq s *the-class-string-stream*)))
+      (eq s *the-class-file-stream*) (eq s *the-class-string-stream*)
+      ;; This probably shouldn't be mixed in with certain other
+      ;; classes, too, but it seems to work both with STANDARD-OBJECT
+      ;; and FUNCALLABLE-STANDARD-OBJECT
+      (eq s *the-class-sequence*)))
 
 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
 (defmethod class-direct-slots ((class forward-referenced-class)) ())
@@ -1528,7 +1656,7 @@
   t)
 
 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
-  (pushnew dependent (plist-value metaobject 'dependents)))
+  (pushnew dependent (plist-value metaobject 'dependents) :test #'eq))
 
 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
   (setf (plist-value metaobject 'dependents)