X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fpcl%2Fdfun.lisp;h=cc6d267f4f4d591dcdfc3bba19671fcae7960b90;hb=a57db6f5ee029a4c9817ae239d7bbefd3fb8374e;hp=7e0b1be484013d6c99654bb41e8fde55a074a8bc;hpb=0a82f2db352cc348d2107a882e50af222ff97ed3;p=sbcl.git

diff --git a/src/pcl/dfun.lisp b/src/pcl/dfun.lisp
index 7e0b1be..cc6d267 100644
--- a/src/pcl/dfun.lisp
+++ b/src/pcl/dfun.lisp
@@ -75,6 +75,8 @@ have to do any method lookup to implement itself.
 
 And so, we are saved.
 
+Except see also BREAK-VICIOUS-METACIRCLE.  -- CSR, 2003-05-28
+
 |#
 
 ;;; an alist in which each entry is of the form
@@ -103,10 +105,10 @@ And so, we are saved.
   (when (and *raise-metatypes-to-class-p*
 	     (member generator '(emit-checking emit-caching
 				 emit-in-checking-cache-p emit-constant-value)))
-    (setq args (cons (mapcar #'(lambda (mt)
-				 (if (eq mt t)
-				     mt
-				     'class))
+    (setq args (cons (mapcar (lambda (mt)
+			       (if (eq mt t)
+				   mt
+				   'class))
 			     (car args))
 		     (cdr args))))
   (let* ((generator-entry (assq generator *dfun-constructors*))
@@ -156,19 +158,76 @@ And so, we are saved.
 (defmacro precompile-dfun-constructors (&optional system)
   (let ((*precompiling-lap* t))
     `(progn
-       ,@(gathering1 (collecting)
+       ,@(let (collect)
 	   (dolist (generator-entry *dfun-constructors*)
 	     (dolist (args-entry (cdr generator-entry))
 	       (when (or (null (caddr args-entry))
 			 (eq (caddr args-entry) system))
 		 (when system (setf (caddr args-entry) system))
-		 (gather1
-                  `(load-precompiled-dfun-constructor
-                    ',(car generator-entry)
-                    ',(car args-entry)
-                    ',system
-                    ,(apply (fdefinition (car generator-entry))
-                            (car args-entry)))))))))))
+		 (push `(load-precompiled-dfun-constructor
+                         ',(car generator-entry)
+                         ',(car args-entry)
+                         ',system
+                         ,(apply (fdefinition (car generator-entry))
+                                 (car args-entry)))
+                       collect))))
+           (nreverse collect)))))
+
+;;; Standardized class slot access: when trying to break vicious
+;;; metacircles, we need a way to get at the values of slots of some
+;;; standard classes without going through the whole meta machinery,
+;;; because that would likely enter the vicious circle again.  The
+;;; following are helper functions that short-circuit the generic
+;;; lookup machinery.
+
+(defvar *standard-classes*
+  '(standard-method standard-generic-function standard-class
+    standard-effective-slot-definition))
+
+(defvar *standard-slot-locations* (make-hash-table :test 'equal))
+
+(defun compute-standard-slot-locations ()
+  (clrhash *standard-slot-locations*)
+  (dolist (class-name *standard-classes*)
+    (let ((class (find-class class-name)))
+      (dolist (slot (class-slots class))
+	(setf (gethash (cons class (slot-definition-name slot))
+		       *standard-slot-locations*)
+	      (slot-definition-location slot))))))
+
+;;; FIXME: harmonize the names between COMPUTE-STANDARD-SLOT-LOCATIONS
+;;; and MAYBE-UPDATE-STANDARD-CLASS-LOCATIONS.
+(defun maybe-update-standard-class-locations (class)
+  (when (and (eq *boot-state* 'complete)
+	     (memq (class-name class) *standard-classes*))
+    (compute-standard-slot-locations)))
+
+(defun standard-slot-value (object slot-name class)
+  (let ((location (gethash (cons class slot-name) *standard-slot-locations*)))
+    (if location
+	(let ((value (if (funcallable-instance-p object)
+			 (funcallable-standard-instance-access object location)
+			 (standard-instance-access object location))))
+	  (when (eq +slot-unbound+ value)
+	    (error "~@<slot ~s of class ~s is unbound in object ~s~@:>"
+		   slot-name class object))
+	  value)
+	(error "~@<cannot get standard value of slot ~s of class ~s ~
+                in object ~s~@:>"
+	       slot-name class object))))
+
+(defun standard-slot-value/gf (gf slot-name)
+  (standard-slot-value gf slot-name *the-class-standard-generic-function*))
+
+(defun standard-slot-value/method (method slot-name)
+  (standard-slot-value method slot-name *the-class-standard-method*))
+
+(defun standard-slot-value/eslotd (slotd slot-name)
+  (standard-slot-value slotd slot-name
+		       *the-class-standard-effective-slot-definition*))
+
+(defun standard-slot-value/class (class slot-name)
+  (standard-slot-value class slot-name *the-class-standard-class*))
 
 ;;; When all the methods of a generic function are automatically
 ;;; generated reader or writer methods a number of special
@@ -301,7 +360,7 @@ And so, we are saved.
 
 (defun accessor-miss-function (gf dfun-info)
   (ecase (dfun-info-accessor-type dfun-info)
-    (reader
+    ((reader boundp)
      (lambda (arg)
        (accessor-miss gf nil arg dfun-info)))
     (writer
@@ -311,7 +370,10 @@ And so, we are saved.
 #-sb-fluid (declaim (sb-ext:freeze-type dfun-info))
 
 (defun make-one-class-accessor-dfun (gf type wrapper index)
-  (let ((emit (if (eq type 'reader) 'emit-one-class-reader 'emit-one-class-writer))
+  (let ((emit (ecase type
+		(reader 'emit-one-class-reader)
+		(boundp 'emit-one-class-boundp)
+		(writer 'emit-one-class-writer)))
 	(dfun-info (one-class-dfun-info type index wrapper)))
     (values
      (funcall (get-dfun-constructor emit (consp index))
@@ -321,7 +383,10 @@ And so, we are saved.
      dfun-info)))
 
 (defun make-two-class-accessor-dfun (gf type w0 w1 index)
-  (let ((emit (if (eq type 'reader) 'emit-two-class-reader 'emit-two-class-writer))
+  (let ((emit (ecase type
+		(reader 'emit-two-class-reader)
+		(boundp 'emit-two-class-boundp)
+		(writer 'emit-two-class-writer)))
 	(dfun-info (two-class-dfun-info type index w0 w1)))
     (values
      (funcall (get-dfun-constructor emit (consp index))
@@ -332,7 +397,10 @@ And so, we are saved.
 
 ;;; std accessors same index dfun
 (defun make-one-index-accessor-dfun (gf type index &optional cache)
-  (let* ((emit (if (eq type 'reader) 'emit-one-index-readers 'emit-one-index-writers))
+  (let* ((emit (ecase type
+		 (reader 'emit-one-index-readers)
+		 (boundp 'emit-one-index-boundps)
+		 (writer 'emit-one-index-writers)))
 	 (cache (or cache (get-cache 1 nil #'one-index-limit-fn 4)))
 	 (dfun-info (one-index-dfun-info type index cache)))
     (declare (type cache cache))
@@ -352,7 +420,10 @@ And so, we are saved.
   (default-limit-fn nlines))
 
 (defun make-n-n-accessor-dfun (gf type &optional cache)
-  (let* ((emit (if (eq type 'reader) 'emit-n-n-readers 'emit-n-n-writers))
+  (let* ((emit (ecase type
+		 (reader 'emit-n-n-readers)
+		 (boundp 'emit-n-n-boundps)
+		 (writer 'emit-n-n-writers)))
 	 (cache (or cache (get-cache 1 t #'n-n-accessors-limit-fn 2)))
 	 (dfun-info (n-n-dfun-info type cache)))
     (declare (type cache cache))
@@ -377,9 +448,9 @@ And so, we are saved.
     (when (use-dispatch-dfun-p generic-function)
       (return-from make-checking-dfun (make-dispatch-dfun generic-function))))
   (multiple-value-bind (nreq applyp metatypes nkeys)
-      (get-generic-function-info generic-function)
+      (get-generic-fun-info generic-function)
     (declare (ignore nreq))
-    (if (every #'(lambda (mt) (eq mt t)) metatypes)
+    (if (every (lambda (mt) (eq mt t)) metatypes)
 	(let ((dfun-info (default-method-only-dfun-info)))
 	  (values
 	   (funcall (get-dfun-constructor 'emit-default-only metatypes applyp)
@@ -400,9 +471,9 @@ And so, we are saved.
 (defun make-final-checking-dfun (generic-function function
 						  classes-list new-class)
   (let ((metatypes (arg-info-metatypes (gf-arg-info generic-function))))
-    (if (every #'(lambda (mt) (eq mt t)) metatypes)
-	(values #'(lambda (&rest args)
-		    (invoke-emf function args))
+    (if (every (lambda (mt) (eq mt t)) metatypes)
+	(values (lambda (&rest args)
+		  (invoke-emf function args))
 		nil (default-method-only-dfun-info))
 	(let ((cache (make-final-ordinary-dfun-internal
 		      generic-function nil #'checking-limit-fn
@@ -411,16 +482,16 @@ And so, we are saved.
 
 (defun use-default-method-only-dfun-p (generic-function)
   (multiple-value-bind (nreq applyp metatypes nkeys)
-      (get-generic-function-info generic-function)
+      (get-generic-fun-info generic-function)
     (declare (ignore nreq applyp nkeys))
-    (every #'(lambda (mt) (eq mt t)) metatypes)))
+    (every (lambda (mt) (eq mt t)) metatypes)))
 
 (defun use-caching-dfun-p (generic-function)
   (some (lambda (method)
 	  (let ((fmf (if (listp method)
 			 (third method)
 			 (method-fast-function method))))
-	    (method-function-get fmf ':slot-name-lists)))
+	    (method-function-get fmf :slot-name-lists)))
 	;; KLUDGE: As of sbcl-0.6.4, it's very important for
 	;; efficiency to know the type of the sequence argument to
 	;; quantifiers (SOME/NOTANY/etc.) at compile time, but
@@ -438,11 +509,13 @@ And so, we are saved.
 (defun make-caching-dfun (generic-function &optional cache)
   (unless cache
     (when (use-constant-value-dfun-p generic-function)
-      (return-from make-caching-dfun (make-constant-value-dfun generic-function)))
+      (return-from make-caching-dfun
+	(make-constant-value-dfun generic-function)))
     (when (use-dispatch-dfun-p generic-function)
-      (return-from make-caching-dfun (make-dispatch-dfun generic-function))))
+      (return-from make-caching-dfun
+	(make-dispatch-dfun generic-function))))
   (multiple-value-bind (nreq applyp metatypes nkeys)
-      (get-generic-function-info generic-function)
+      (get-generic-fun-info generic-function)
     (declare (ignore nreq))
     (let* ((cache (or cache (get-cache nkeys t #'caching-limit-fn 2)))
 	   (dfun-info (caching-dfun-info cache)))
@@ -465,7 +538,7 @@ And so, we are saved.
 
 (defun insure-caching-dfun (gf)
   (multiple-value-bind (nreq applyp metatypes nkeys)
-      (get-generic-function-info gf)
+      (get-generic-fun-info gf)
     (declare (ignore nreq nkeys))
     (when (and metatypes
 	       (not (null (car metatypes)))
@@ -475,7 +548,7 @@ And so, we are saved.
 
 (defun use-constant-value-dfun-p (gf &optional boolean-values-p)
   (multiple-value-bind (nreq applyp metatypes nkeys)
-      (get-generic-function-info gf)
+      (get-generic-fun-info gf)
     (declare (ignore nreq metatypes nkeys))
     (let* ((early-p (early-gf-p gf))
 	   (methods (if early-p
@@ -484,25 +557,45 @@ And so, we are saved.
 	   (default '(unknown)))
       (and (null applyp)
 	   (or (not (eq *boot-state* 'complete))
-	       (compute-applicable-methods-emf-std-p gf))
-	   (notany #'(lambda (method)
-		       (or (and (eq *boot-state* 'complete)
-				(some #'eql-specializer-p
-				      (method-specializers method)))
-			   (let ((value (method-function-get
-					 (if early-p
-					     (or (third method) (second method))
-					     (or (method-fast-function method)
-						 (method-function method)))
-					 :constant-value default)))
-			     (if boolean-values-p
-				 (not (or (eq value t) (eq value nil)))
-				 (eq value default)))))
-		   methods)))))
+	       ;; If COMPUTE-APPLICABLE-METHODS is specialized, we
+	       ;; can't use this, of course, because we can't tell
+	       ;; which methods will be considered applicable.
+	       ;;
+	       ;; Also, don't use this dfun method if the generic
+	       ;; function has a non-standard method combination,
+	       ;; because if it has, it's not sure that method
+	       ;; functions are used directly as effective methods,
+	       ;; which CONSTANT-VALUE-MISS depends on.  The
+	       ;; pre-defined method combinations like LIST are
+	       ;; examples of that.
+	       (and (compute-applicable-methods-emf-std-p gf)
+		    (eq (generic-function-method-combination gf)
+			*standard-method-combination*)))
+	   ;; Check that no method is eql-specialized, and that all
+	   ;; methods return a constant value.  If BOOLEAN-VALUES-P,
+	   ;; check that all return T or NIL.  Also, check that no
+	   ;; method has qualifiers, to make sure that emfs are really
+	   ;; method functions; see above.
+	   (dolist (method methods t)
+	     (when (eq *boot-state* 'complete)
+	       (when (or (some #'eql-specializer-p
+			       (method-specializers method))
+			 (method-qualifiers method))
+		 (return nil)))
+	     (let ((value (method-function-get
+			   (if early-p
+			       (or (third method) (second method))
+			       (or (method-fast-function method)
+				   (method-function method)))
+			   :constant-value default)))
+	       (when (or (eq value default)
+			 (and boolean-values-p
+			      (not (member value '(t nil)))))
+		 (return nil))))))))
 
 (defun make-constant-value-dfun (generic-function &optional cache)
   (multiple-value-bind (nreq applyp metatypes nkeys)
-      (get-generic-function-info generic-function)
+      (get-generic-fun-info generic-function)
     (declare (ignore nreq applyp))
     (let* ((cache (or cache (get-cache nkeys t #'caching-limit-fn 2)))
 	   (dfun-info (constant-value-dfun-info cache)))
@@ -547,27 +640,27 @@ And so, we are saved.
 (defun dispatch-dfun-cost (gf &optional limit)
   (generate-discrimination-net-internal
    gf (generic-function-methods gf) nil
-   #'(lambda (methods known-types)
-       (declare (ignore methods known-types))
-       0)
-   #'(lambda (position type true-value false-value)
-       (declare (ignore position))
-       (let* ((type-test-cost
-	       (if (eq 'class (car type))
-		   (let* ((metaclass (class-of (cadr type)))
-			  (mcpl (class-precedence-list metaclass)))
-		     (cond ((memq *the-class-built-in-class* mcpl)
-			    *built-in-typep-cost*)
-			   ((memq *the-class-structure-class* mcpl)
-			    *structure-typep-cost*)
-			   (t
-			    *non-built-in-typep-cost*)))
-		   0))
-	      (max-cost-so-far
-	       (+ (max true-value false-value) type-test-cost)))
-	 (when (and limit (<= limit max-cost-so-far))
-	   (return-from dispatch-dfun-cost max-cost-so-far))
-	   max-cost-so-far))
+   (lambda (methods known-types)
+     (declare (ignore methods known-types))
+     0)
+   (lambda (position type true-value false-value)
+     (declare (ignore position))
+     (let* ((type-test-cost
+	     (if (eq 'class (car type))
+		 (let* ((metaclass (class-of (cadr type)))
+			(mcpl (class-precedence-list metaclass)))
+		   (cond ((memq *the-class-built-in-class* mcpl)
+			  *built-in-typep-cost*)
+			 ((memq *the-class-structure-class* mcpl)
+			  *structure-typep-cost*)
+			 (t
+			  *non-built-in-typep-cost*)))
+		 0))
+	    (max-cost-so-far
+	     (+ (max true-value false-value) type-test-cost)))
+       (when (and limit (<= limit max-cost-so-far))
+	 (return-from dispatch-dfun-cost max-cost-so-far))
+       max-cost-so-far))
    #'identity))
 
 (defparameter *cache-lookup-cost* 1)
@@ -610,11 +703,10 @@ And so, we are saved.
 (defun fill-dfun-cache (table valuep nkeys limit-fn &optional cache)
   (let ((cache (or cache (get-cache nkeys valuep limit-fn
 				    (+ (hash-table-count table) 3)))))
-    (maphash #'(lambda (classes value)
-		 (setq cache (fill-cache cache
-					 (class-wrapper classes)
-					 value
-					 t)))
+    (maphash (lambda (classes value)
+	       (setq cache (fill-cache cache
+				       (class-wrapper classes)
+				       value)))
 	     table)
     cache))
 
@@ -644,10 +736,19 @@ And so, we are saved.
        (cache-miss-values ,gf ,args ',(cond (caching-p 'caching)
 					    (type 'accessor)
 					    (t 'checking)))
-     (when (and ,applicable (not (memq ,gf *dfun-miss-gfs-on-stack*)))
-       (let ((*dfun-miss-gfs-on-stack* (cons ,gf *dfun-miss-gfs-on-stack*)))
-	 ,@body))
-     (invoke-emf ,nemf ,args)))
+    (when (and ,applicable (not (memq ,gf *dfun-miss-gfs-on-stack*)))
+      (let ((*dfun-miss-gfs-on-stack* (cons ,gf *dfun-miss-gfs-on-stack*)))
+	,@body))
+    ;; Create a FAST-INSTANCE-BOUNDP structure instance for a cached
+    ;; SLOT-BOUNDP so that INVOKE-EMF does the right thing, that is,
+    ;; does not signal a SLOT-UNBOUND error for a boundp test.
+    ,@(if type
+	  ;; FIXME: could the NEMF not be a CONS (for :CLASS-allocated
+	  ;; slots?)
+	  `((if (and (eq ,type 'boundp) (integerp ,nemf))
+		(invoke-emf (make-fast-instance-boundp :index ,nemf) ,args)
+		(invoke-emf ,nemf ,args)))
+	  `((invoke-emf ,nemf ,args)))))
 
 ;;; The dynamically adaptive method lookup algorithm is implemented is
 ;;; implemented as a kind of state machine. The kinds of
@@ -662,50 +763,78 @@ And so, we are saved.
 ;;; considered as state transitions.
 (defvar *lazy-dfun-compute-p* t)
 (defvar *early-p* nil)
+(defvar *max-emf-precomputation-methods* 10)
+
+(defun finalize-specializers (gf)
+  (let ((methods (generic-function-methods gf)))
+    (when (<= (length methods) *max-emf-precomputation-methods*)
+      (let ((all-finalized t))
+	(dolist (method methods all-finalized)
+	  (dolist (specializer (method-specializers method))
+	    (when (and (classp specializer)
+		       (not (class-finalized-p specializer)))
+	      (if (class-has-a-forward-referenced-superclass-p specializer)
+		  (setq all-finalized nil)
+		  (finalize-inheritance specializer)))))))))
 
 (defun make-initial-dfun (gf)
   (let ((initial-dfun
-	 #'(sb-kernel:instance-lambda (&rest args)
+	 #'(instance-lambda (&rest args)
 	     (initial-dfun gf args))))
     (multiple-value-bind (dfun cache info)
-	(if (and (eq *boot-state* 'complete)
-		 (compute-applicable-methods-emf-std-p gf))
-	    (let* ((caching-p (use-caching-dfun-p gf))
-		   (classes-list (precompute-effective-methods
-				  gf caching-p
-				  (not *lazy-dfun-compute-p*))))
-	      (if *lazy-dfun-compute-p*
-		  (cond ((use-dispatch-dfun-p gf caching-p)
-			 (values initial-dfun
-				 nil
-				 (initial-dispatch-dfun-info)))
-			(caching-p
-			 (insure-caching-dfun gf)
-			 (values initial-dfun nil (initial-dfun-info)))
-			(t
-			 (values initial-dfun nil (initial-dfun-info))))
-		  (make-final-dfun-internal gf classes-list)))
-	    (let ((arg-info (if (early-gf-p gf)
-				(early-gf-arg-info gf)
-				(gf-arg-info gf)))
-		  (type nil))
-	      (if (and (gf-precompute-dfun-and-emf-p arg-info)
-		       (setq type (final-accessor-dfun-type gf)))
-		  (if *early-p*
-		      (values (make-early-accessor gf type) nil nil)
-		      (make-final-accessor-dfun gf type))
-		  (values initial-dfun nil (initial-dfun-info)))))
+	(cond
+	  ((and (eq *boot-state* 'complete)
+		(not (finalize-specializers gf)))
+	   (values initial-dfun nil (initial-dfun-info)))
+	  ((and (eq *boot-state* 'complete)
+		(compute-applicable-methods-emf-std-p gf))
+	   (let* ((caching-p (use-caching-dfun-p gf))
+		  ;; KLUDGE: the only effect of this (when
+		  ;; *LAZY-DFUN-COMPUTE-P* is true, as it usually is)
+		  ;; is to signal an error when we try to add methods
+		  ;; with the wrong qualifiers to a generic function.
+		  (classes-list (precompute-effective-methods
+				 gf caching-p
+				 (not *lazy-dfun-compute-p*))))
+	     (if *lazy-dfun-compute-p*
+		 (cond ((use-dispatch-dfun-p gf caching-p)
+			(values initial-dfun
+				nil
+				(initial-dispatch-dfun-info)))
+		       (caching-p
+			(insure-caching-dfun gf)
+			(values initial-dfun nil (initial-dfun-info)))
+		       (t
+			(values initial-dfun nil (initial-dfun-info))))
+		 (make-final-dfun-internal gf classes-list))))
+	  (t
+	   (let ((arg-info (if (early-gf-p gf)
+			       (early-gf-arg-info gf)
+			       (gf-arg-info gf)))
+		 (type nil))
+	     (if (and (gf-precompute-dfun-and-emf-p arg-info)
+		      (setq type (final-accessor-dfun-type gf)))
+		 (if *early-p*
+		     (values (make-early-accessor gf type) nil nil)
+		     (make-final-accessor-dfun gf type))
+		 (values initial-dfun nil (initial-dfun-info))))))
       (set-dfun gf dfun cache info))))
 
 (defun make-early-accessor (gf type)
   (let* ((methods (early-gf-methods gf))
 	 (slot-name (early-method-standard-accessor-slot-name (car methods))))
     (ecase type
-      (reader #'(sb-kernel:instance-lambda (instance)
+      (reader #'(instance-lambda (instance)
 		  (let* ((class (class-of instance))
 			 (class-name (!bootstrap-get-slot 'class class 'name)))
 		    (!bootstrap-get-slot class-name instance slot-name))))
-      (writer #'(sb-kernel:instance-lambda (new-value instance)
+      (boundp #'(instance-lambda (instance)
+		  (let* ((class (class-of instance))
+			 (class-name (!bootstrap-get-slot 'class class 'name)))
+		    (not (eq +slot-unbound+
+			     (!bootstrap-get-slot class-name
+						  instance slot-name))))))
+      (writer #'(instance-lambda (new-value instance)
 		  (let* ((class (class-of instance))
 			 (class-name (!bootstrap-get-slot 'class class 'name)))
 		    (!bootstrap-set-slot class-name instance slot-name new-value)))))))
@@ -750,18 +879,25 @@ And so, we are saved.
   (let ((methods (if (early-gf-p gf)
 		     (early-gf-methods gf)
 		     (generic-function-methods gf))))
-    (cond ((every #'(lambda (method)
-		      (if (consp method)
-			  (eq *the-class-standard-reader-method*
-			      (early-method-class method))
-			  (standard-reader-method-p method)))
+    (cond ((every (lambda (method)
+		    (if (consp method)
+			(eq *the-class-standard-reader-method*
+			    (early-method-class method))
+			(standard-reader-method-p method)))
 		  methods)
 	   'reader)
-	  ((every #'(lambda (method)
-		      (if (consp method)
-			  (eq *the-class-standard-writer-method*
-			      (early-method-class method))
-			  (standard-writer-method-p method)))
+	  ((every (lambda (method)
+		    (if (consp method)
+			(eq *the-class-standard-boundp-method*
+			    (early-method-class method))
+			(standard-boundp-method-p method)))
+		  methods)
+	   'boundp)
+	  ((every (lambda (method)
+		    (if (consp method)
+			(eq *the-class-standard-writer-method*
+			    (early-method-class method))
+			(standard-writer-method-p method)))
 		  methods)
 	   'writer))))
 
@@ -792,20 +928,20 @@ And so, we are saved.
 	specls all-same-p)
     (cond ((null methods)
 	   (values
-	    #'(sb-kernel:instance-lambda (&rest args)
+	    #'(instance-lambda (&rest args)
 		(apply #'no-applicable-method gf args))
 	    nil
 	    (no-methods-dfun-info)))
 	  ((setq type (final-accessor-dfun-type gf))
 	   (make-final-accessor-dfun gf type classes-list new-class))
-	  ((and (not (and (every #'(lambda (specl) (eq specl *the-class-t*))
+	  ((and (not (and (every (lambda (specl) (eq specl *the-class-t*))
 				 (setq specls
 				       (method-specializers (car methods))))
 			  (setq all-same-p
-				(every #'(lambda (method)
-					   (and (equal specls
-						       (method-specializers
-							method))))
+				(every (lambda (method)
+					 (and (equal specls
+						     (method-specializers
+						      method))))
 				       methods))))
 		(use-constant-value-dfun-p gf))
 	   (make-final-constant-value-dfun gf classes-list new-class))
@@ -821,9 +957,11 @@ And so, we are saved.
   (let* ((ostate (type-of dfun-info))
 	 (otype (dfun-info-accessor-type dfun-info))
 	 oindex ow0 ow1 cache
-	 (args (ecase otype			; The congruence rules ensure
-		(reader (list object))		; that this is safe despite not
-		(writer (list new object)))))	; knowing the new type yet.
+	 (args (ecase otype
+		 ;; The congruence rules ensure that this is safe
+		 ;; despite not knowing the new type yet.
+		 ((reader boundp) (list object))
+		 (writer (list new object)))))	
     (dfun-miss (gf args wrappers invalidp nemf ntype nindex)
 
       ;; The following lexical functions change the state of the
@@ -885,8 +1023,8 @@ And so, we are saved.
 		  (setq oindex (dfun-info-index dfun-info))
 		  (setq cache (dfun-info-cache dfun-info))
 		  (if (eql nindex oindex)
-		      (do-fill #'(lambda (ncache)
-				   (one-index nindex ncache)))
+		      (do-fill (lambda (ncache)
+				 (one-index nindex ncache)))
 		      (n-n)))
 		 (n-n
 		  (setq cache (dfun-info-cache dfun-info))
@@ -920,17 +1058,19 @@ And so, we are saved.
 (defun constant-value-miss (generic-function args dfun-info)
   (let ((ocache (dfun-info-cache dfun-info)))
     (dfun-miss (generic-function args wrappers invalidp emf nil nil t)
-      (cond (invalidp)
-	    (t
-	     (let* ((function (typecase emf
-				(fast-method-call (fast-method-call-function
-						   emf))
-				(method-call (method-call-function emf))))
-		    (value (method-function-get function :constant-value))
-		    (ncache (fill-cache ocache wrappers value)))
-	       (unless (eq ncache ocache)
-		 (dfun-update generic-function
-			      #'make-constant-value-dfun ncache))))))))
+      (unless invalidp
+	(let* ((function
+		(typecase emf
+		  (fast-method-call (fast-method-call-function emf))
+		  (method-call (method-call-function emf))))
+	       (value (let ((val (method-function-get
+				  function :constant-value '.not-found.)))
+			(aver (not (eq val '.not-found.)))
+			val))
+	       (ncache (fill-cache ocache wrappers value)))
+	  (unless (eq ncache ocache)
+	    (dfun-update generic-function
+			 #'make-constant-value-dfun ncache)))))))
 
 ;;; Given a generic function and a set of arguments to that generic
 ;;; function, return a mess of values.
@@ -962,9 +1102,11 @@ And so, we are saved.
 ;;;  <index>      If <type> is READER or WRITER, and the slot accessed is
 ;;;	       an :instance slot, this is the index number of that slot
 ;;;	       in the object argument.
+(defvar *cache-miss-values-stack* ())
+
 (defun cache-miss-values (gf args state)
   (multiple-value-bind (nreq applyp metatypes nkeys arg-info)
-      (get-generic-function-info gf)
+      (get-generic-fun-info gf)
     (declare (ignore nreq applyp nkeys))
     (with-dfun-wrappers (args metatypes)
       (dfun-wrappers invalid-wrapper-p wrappers classes types)
@@ -978,39 +1120,114 @@ And so, we are saved.
                 accessor-type index)))))
 
 (defun cache-miss-values-internal (gf arg-info wrappers classes types state)
+  (if (and classes (equal classes (cdr (assq gf *cache-miss-values-stack*))))
+      (break-vicious-metacircle gf classes arg-info)
+      (let ((*cache-miss-values-stack*
+	     (acons gf classes *cache-miss-values-stack*))
+	    (cam-std-p (or (null arg-info)
+			   (gf-info-c-a-m-emf-std-p arg-info))))
+	(multiple-value-bind (methods all-applicable-and-sorted-p)
+	    (if cam-std-p
+		(compute-applicable-methods-using-types gf types)
+		(compute-applicable-methods-using-classes gf classes))
+	  
   (let* ((for-accessor-p (eq state 'accessor))
 	 (for-cache-p (or (eq state 'caching) (eq state 'accessor)))
-	 (cam-std-p (or (null arg-info)
-			(gf-info-c-a-m-emf-std-p arg-info))))
-    (multiple-value-bind (methods all-applicable-and-sorted-p)
-	(if cam-std-p
-	    (compute-applicable-methods-using-types gf types)
-	    (compute-applicable-methods-using-classes gf classes))
-      (let ((emf (if (or cam-std-p all-applicable-and-sorted-p)
-		     (function-funcall (get-secondary-dispatch-function1
-					gf methods types nil (and for-cache-p
-								  wrappers)
-					all-applicable-and-sorted-p)
-				       nil (and for-cache-p wrappers))
-		     (default-secondary-dispatch-function gf))))
-	(multiple-value-bind (index accessor-type)
-	    (and for-accessor-p all-applicable-and-sorted-p methods
-		 (accessor-values gf arg-info classes methods))
-	  (values (if (integerp index) index emf)
-		  methods accessor-type index))))))
+	 (emf (if (or cam-std-p all-applicable-and-sorted-p)
+		  (function-funcall (get-secondary-dispatch-function1
+				     gf methods types nil (and for-cache-p
+							       wrappers)
+				     all-applicable-and-sorted-p)
+				    nil (and for-cache-p wrappers))
+		  (default-secondary-dispatch-function gf))))
+    (multiple-value-bind (index accessor-type)
+	(and for-accessor-p all-applicable-and-sorted-p methods
+	     (accessor-values gf arg-info classes methods))
+      (values (if (integerp index) index emf)
+	      methods accessor-type index)))))))
+
+;;; Try to break a vicious circle while computing a cache miss.
+;;; GF is the generic function, CLASSES are the classes of actual
+;;; arguments, and ARG-INFO is the generic functions' arg-info.
+;;;
+;;; A vicious circle can be entered when the computation of the cache
+;;; miss values itself depends on the values being computed.  For
+;;; instance, adding a method which is an instance of a subclass of
+;;; STANDARD-METHOD leads to cache misses for slot accessors of
+;;; STANDARD-METHOD like METHOD-SPECIALIZERS, and METHOD-SPECIALIZERS
+;;; is itself used while we compute cache miss values.
+(defun break-vicious-metacircle (gf classes arg-info)
+  (when (typep gf 'standard-generic-function)
+    (multiple-value-bind (class slotd accessor-type)
+	(accesses-standard-class-slot-p gf)
+      (when class
+	(let ((method (find-standard-class-accessor-method
+		       gf class accessor-type))
+	      (index (standard-slot-value/eslotd slotd 'location))
+	      (type (gf-info-simple-accessor-type arg-info)))
+	  (when (and method
+		     (subtypep (ecase accessor-type
+				 ((reader) (car classes))
+				 ((writer) (cadr classes)))
+			       class))
+	    (return-from break-vicious-metacircle
+	      (values index (list method) type index)))))))
+  (error "~@<vicious metacircle:  The computation of an ~
+	  effective method of ~s for arguments of types ~s uses ~
+	  the effective method being computed.~@:>"
+	 gf classes))
+
+;;; Return (CLASS SLOTD ACCESSOR-TYPE) if some method of generic
+;;; function GF accesses a slot of some class in *STANDARD-CLASSES*.
+;;; CLASS is the class accessed, SLOTD is the effective slot definition
+;;; object of the slot accessed, and ACCESSOR-TYPE is one of the symbols
+;;; READER or WRITER describing the slot access.
+(defun accesses-standard-class-slot-p (gf)
+  (flet ((standard-class-slot-access (gf class)
+	   (loop with gf-name = (standard-slot-value/gf gf 'name)
+		 for slotd in (standard-slot-value/class class 'slots)
+		 ;; FIXME: where does BOUNDP fit in here?  Is it
+		 ;; relevant?
+		 as readers = (standard-slot-value/eslotd slotd 'readers)
+		 as writers = (standard-slot-value/eslotd slotd 'writers)
+		 if (member gf-name readers :test #'equal)
+		   return (values slotd 'reader)
+		 else if (member gf-name writers :test #'equal)
+		   return (values slotd 'writer))))
+    (dolist (class-name *standard-classes*)
+      (let ((class (find-class class-name)))
+	(multiple-value-bind (slotd accessor-type)
+	    (standard-class-slot-access gf class)
+	  (when slotd
+	    (return (values class slotd accessor-type))))))))
+
+;;; Find a slot reader/writer method among the methods of generic
+;;; function GF which reads/writes instances of class CLASS.
+;;; TYPE is one of the symbols READER or WRITER.
+(defun find-standard-class-accessor-method (gf class type)
+  (dolist (method (standard-slot-value/gf gf 'methods))
+    (let ((specializers (standard-slot-value/method method 'specializers))
+	  (qualifiers (plist-value method 'qualifiers)))
+      (when (and (null qualifiers)
+		 (eq (ecase type
+		       (reader (car specializers))
+		       (writer (cadr specializers)))
+		     class))
+	(return method)))))
 
 (defun accessor-values (gf arg-info classes methods)
   (declare (ignore gf))
   (let* ((accessor-type (gf-info-simple-accessor-type arg-info))
 	 (accessor-class (case accessor-type
-			   (reader (car classes))
-			   (writer (cadr classes))
-			   (boundp (car classes)))))
+			   ((reader boundp) (car classes))
+			   (writer (cadr classes)))))
     (accessor-values-internal accessor-type accessor-class methods)))
 
 (defun accessor-values1 (gf accessor-type accessor-class)
   (let* ((type `(class-eq ,accessor-class))
-	 (types (if (eq accessor-type 'writer) `(t ,type) `(,type)))
+	 (types (ecase accessor-type
+		  ((reader boundp) `(,type))
+		  (writer `(t ,type))))
 	 (methods (compute-applicable-methods-using-types gf types)))
     (accessor-values-internal accessor-type accessor-class methods)))
 
@@ -1069,9 +1286,9 @@ And so, we are saved.
       (let* ((specializers (if (consp method)
 			       (early-method-specializers method t)
 			       (method-specializers method)))
-	     (specl (if (eq type 'reader)
-			(car specializers)
-			(cadr specializers)))
+	     (specl (ecase type
+		      ((reader boundp) (car specializers))
+		      (writer (cadr specializers))))
 	     (specl-cpl (if early-p
 			    (early-class-precedence-list specl)
 			    (and (class-finalized-p specl)
@@ -1085,39 +1302,39 @@ And so, we are saved.
 	(when (or (null specl-cpl)
 		  (member *the-class-structure-object* specl-cpl))
 	  (return-from make-accessor-table nil))
-	(maphash #'(lambda (class slotd)
-		     (let ((cpl (if early-p
-				    (early-class-precedence-list class)
-				    (class-precedence-list class))))
-		       (when (memq specl cpl)
-			 (unless (and (or so-p
-					  (member *the-class-std-object* cpl))
-				      (or early-p
-					  (slot-accessor-std-p slotd type)))
-			   (return-from make-accessor-table nil))
-			 (push (cons specl slotd) (gethash class table)))))
+	(maphash (lambda (class slotd)
+		   (let ((cpl (if early-p
+				  (early-class-precedence-list class)
+				  (class-precedence-list class))))
+		     (when (memq specl cpl)
+		       (unless (and (or so-p
+					(member *the-class-std-object* cpl))
+				    (or early-p
+					(slot-accessor-std-p slotd type)))
+			 (return-from make-accessor-table nil))
+		       (push (cons specl slotd) (gethash class table)))))
 		 (gethash slot-name *name->class->slotd-table*))))
-    (maphash #'(lambda (class specl+slotd-list)
-		 (dolist (sclass (if early-p
-				    (early-class-precedence-list class)
-				    (class-precedence-list class))
-			  (error "This can't happen."))
-		   (let ((a (assq sclass specl+slotd-list)))
-		     (when a
-		       (let* ((slotd (cdr a))
-			      (index (if early-p
-					 (early-slot-definition-location slotd)
-					 (slot-definition-location slotd))))
-			 (unless index (return-from make-accessor-table nil))
-			 (setf (gethash class table) index)
-			 (when (consp index) (setq no-class-slots-p nil))
-			 (setq all-index (if (or (null all-index)
-						 (eql all-index index))
-					     index t))
-			 (incf size)
-			 (cond ((= size 1) (setq first class))
-			       ((= size 2) (setq second class)))
-			 (return nil))))))
+    (maphash (lambda (class specl+slotd-list)
+	       (dolist (sclass (if early-p
+				   (early-class-precedence-list class)
+				   (class-precedence-list class))
+			       (error "This can't happen."))
+		 (let ((a (assq sclass specl+slotd-list)))
+		   (when a
+		     (let* ((slotd (cdr a))
+			    (index (if early-p
+				       (early-slot-definition-location slotd)
+				       (slot-definition-location slotd))))
+		       (unless index (return-from make-accessor-table nil))
+		       (setf (gethash class table) index)
+		       (when (consp index) (setq no-class-slots-p nil))
+		       (setq all-index (if (or (null all-index)
+					       (eql all-index index))
+					   index t))
+		       (incf size)
+		       (cond ((= size 1) (setq first class))
+			     ((= size 2) (setq second class)))
+		       (return nil))))))
 	     table)
     (values table all-index first second size no-class-slots-p)))
 
@@ -1155,13 +1372,13 @@ And so, we are saved.
 (defun sort-applicable-methods (precedence methods types)
   (sort-methods methods
 		precedence
-		#'(lambda (class1 class2 index)
-		    (let* ((class (type-class (nth index types)))
-			   (cpl (if (eq *boot-state* 'complete)
-				    (class-precedence-list class)
-				    (early-class-precedence-list class))))
-		      (if (memq class2 (memq class1 cpl))
-			  class1 class2)))))
+		(lambda (class1 class2 index)
+		  (let* ((class (type-class (nth index types)))
+			 (cpl (if (eq *boot-state* 'complete)
+				  (class-precedence-list class)
+				  (early-class-precedence-list class))))
+		    (if (memq class2 (memq class1 cpl))
+			class1 class2)))))
 
 (defun sort-methods (methods precedence compare-classes-function)
   (flet ((sorter (method1 method2)
@@ -1267,6 +1484,12 @@ And so, we are saved.
       (mapcar (lambda (x) (position x lambda-list))
 	      argument-precedence-order)))
 
+(defun cpl-or-nil (class)
+  (if (eq *boot-state* 'complete)
+      (when (class-finalized-p class)
+        (class-precedence-list class))
+      (early-class-precedence-list class)))
+
 (defun saut-and (specl type)
   (let ((applicable nil)
 	(possibly-applicable t))
@@ -1290,8 +1513,8 @@ And so, we are saved.
 
 (defun saut-not-class (specl ntype)
   (let* ((class (type-class specl))
-	 (cpl (class-precedence-list class)))
-     (not (memq (cadr ntype) cpl))))
+	 (cpl (cpl-or-nil class)))
+    (not (memq (cadr ntype) cpl))))
 
 (defun saut-not-prototype (specl ntype)
   (let* ((class (case (car specl)
@@ -1299,8 +1522,8 @@ And so, we are saved.
 		  (class-eq  (cadr specl))
 		  (prototype (cadr specl))
 		  (class     (cadr specl))))
-	 (cpl (class-precedence-list class)))
-     (not (memq (cadr ntype) cpl))))
+	 (cpl (cpl-or-nil class)))
+    (not (memq (cadr ntype) cpl))))
 
 (defun saut-not-class-eq (specl ntype)
   (let ((class (case (car specl)
@@ -1314,9 +1537,7 @@ And so, we are saved.
     (t   t)))
 
 (defun class-applicable-using-class-p (specl type)
-  (let ((pred (memq specl (if (eq *boot-state* 'complete)
-			      (class-precedence-list type)
-			      (early-class-precedence-list type)))))
+  (let ((pred (memq specl (cpl-or-nil type))))
     (values pred
 	    (or pred
 		(if (not *in-precompute-effective-methods-p*)
@@ -1338,7 +1559,7 @@ And so, we are saved.
     (class (class-applicable-using-class-p (cadr specl) (cadr type)))
     (t     (values nil (let ((class (type-class specl)))
 			 (memq (cadr type)
-			       (class-precedence-list class)))))))
+			       (cpl-or-nil class)))))))
 
 (defun saut-class-eq (specl type)
   (if (eq (car specl) 'eql)
@@ -1348,11 +1569,7 @@ And so, we are saved.
 		     (eq (cadr specl) (cadr type)))
 		    (class
 		     (or (eq (cadr specl) (cadr type))
-			 (memq (cadr specl)
-			       (if (eq *boot-state* 'complete)
-				   (class-precedence-list (cadr type))
-				   (early-class-precedence-list
-				    (cadr type)))))))))
+			 (memq (cadr specl) (cpl-or-nil (cadr type))))))))
 	(values pred pred))))
 
 (defun saut-prototype (specl type)
@@ -1365,10 +1582,7 @@ And so, we are saved.
 		(class-eq   (eq (cadr specl) (class-of (cadr type))))
 		(class      (memq (cadr specl)
 				  (let ((class (class-of (cadr type))))
-				    (if (eq *boot-state* 'complete)
-					(class-precedence-list class)
-					(early-class-precedence-list
-					 class))))))))
+				    (cpl-or-nil class)))))))
     (values pred pred)))
 
 (defun specializer-applicable-using-type-p (specl type)
@@ -1403,17 +1617,11 @@ And so, we are saved.
 		    (find-class root)
 		    root)))))
 
-;;; NOTE: We are assuming a restriction on user code that the method
-;;;       combination must not change once it is connected to the
-;;;       generic function.
-;;;
-;;;       This has to be legal, because otherwise any kind of method
-;;;       lookup caching couldn't work. See this by saying that this
-;;;       cache, is just a backing cache for the fast cache. If that
-;;;       cache is legal, this one must be too.
-;;;
-;;; Don't clear this table!
-(defvar *effective-method-table* (make-hash-table :test 'eq))
+(defvar *effective-method-cache* (make-hash-table :test 'eq))
+
+(defun flush-effective-method-cache (generic-function)
+  (dolist (method (generic-function-methods generic-function))
+    (remhash method *effective-method-cache*)))
 
 (defun get-secondary-dispatch-function (gf methods types &optional
 							 method-alist wrappers)
@@ -1432,17 +1640,17 @@ And so, we are saved.
 					    function-p)
   (if (null methods)
       (if function-p
-	  #'(lambda (method-alist wrappers)
-	      (declare (ignore method-alist wrappers))
-	      #'(sb-kernel:instance-lambda (&rest args)
-		  (apply #'no-applicable-method gf args)))
-	  #'(lambda (method-alist wrappers)
-	      (declare (ignore method-alist wrappers))
-	      #'(lambda (&rest args)
-		  (apply #'no-applicable-method gf args))))
+	  (lambda (method-alist wrappers)
+	    (declare (ignore method-alist wrappers))
+	    #'(instance-lambda (&rest args)
+		(apply #'no-applicable-method gf args)))
+	  (lambda (method-alist wrappers)
+	    (declare (ignore method-alist wrappers))
+	    (lambda (&rest args)
+	      (apply #'no-applicable-method gf args))))
       (let* ((key (car methods))
-	     (ht-value (or (gethash key *effective-method-table*)
-			   (setf (gethash key *effective-method-table*)
+	     (ht-value (or (gethash key *effective-method-cache*)
+			   (setf (gethash key *effective-method-cache*)
 				 (cons nil nil)))))
 	(if (and (null (cdr methods)) all-applicable-p ; the most common case
 		 (null method-alist-p) wrappers-p (not function-p))
@@ -1499,15 +1707,13 @@ And so, we are saved.
   (let* ((early-p (early-gf-p generic-function))
 	 (gf-name (if early-p
 		      (!early-gf-name generic-function)
-		      (generic-function-name generic-function)))
-	 (ocache (gf-dfun-cache generic-function)))
+		      (generic-function-name generic-function))))
     (set-dfun generic-function dfun cache info)
     (let ((dfun (if early-p
 		    (or dfun (make-initial-dfun generic-function))
 		    (compute-discriminating-function generic-function))))
-      (set-funcallable-instance-fun generic-function dfun)
+      (set-funcallable-instance-function generic-function dfun)
       (set-fun-name generic-function gf-name)
-      (when (and ocache (not (eq ocache cache))) (free-cache ocache))
       dfun)))
 
 (defvar *dfun-count* nil)
@@ -1566,19 +1772,19 @@ And so, we are saved.
 	(incf (cdr b))))))
 
 (defun count-all-dfuns ()
-  (setq *dfun-count* (mapcar #'(lambda (type) (list type 0 nil))
+  (setq *dfun-count* (mapcar (lambda (type) (list type 0 nil))
 			     '(ONE-CLASS TWO-CLASS DEFAULT-METHOD-ONLY
 			       ONE-INDEX N-N CHECKING CACHING
 			       DISPATCH)))
   (map-all-generic-functions #'count-dfun)
-  (mapc #'(lambda (type+count+sizes)
-	    (setf (third type+count+sizes)
-		  (sort (third type+count+sizes) #'< :key #'car)))
+  (mapc (lambda (type+count+sizes)
+	  (setf (third type+count+sizes)
+		(sort (third type+count+sizes) #'< :key #'car)))
 	*dfun-count*)
-  (mapc #'(lambda (type+count+sizes)
-	    (format t "~&There are ~D dfuns of type ~S."
-		    (cadr type+count+sizes) (car type+count+sizes))
-	    (format t "~%   ~S~%" (caddr type+count+sizes)))
+  (mapc (lambda (type+count+sizes)
+	  (format t "~&There are ~W dfuns of type ~S."
+		  (cadr type+count+sizes) (car type+count+sizes))
+	  (format t "~%   ~S~%" (caddr type+count+sizes)))
 	*dfun-count*)
   (values))
 |#
@@ -1586,8 +1792,8 @@ And so, we are saved.
 (defun gfs-of-type (type)
   (unless (consp type) (setq type (list type)))
   (let ((gf-list nil))
-    (map-all-generic-functions #'(lambda (gf)
-				   (when (memq (type-of (gf-dfun-info gf))
-					       type)
-				     (push gf gf-list))))
+    (map-all-generic-functions (lambda (gf)
+				 (when (memq (type-of (gf-dfun-info gf))
+					     type)
+				   (push gf gf-list))))
     gf-list))