(defun list-with-length-p (x)
(values (ignore-errors (list-length x))))
-;;; not used in 0.7.8, but possibly useful for defensive programming
+;;; not used in 0.7.8, but possibly useful for defensive programming
;;; in e.g. (COERCE ... 'VECTOR)
;;;(defun list-length-or-die (x)
;;; (or (list-length x)
;;; ;; not clear how to do this best:
-;;; ;; * Should this be a TYPE-ERROR? Colloquially that'd make
+;;; ;; * Should this be a TYPE-ERROR? Colloquially that'd make
;;; ;; lots of sense, but since I'm not sure how to express
;;; ;; "noncircular list" as a Lisp type expression, coding
;;; ;; it seems awkward.
;;; ;; be doing him a favor by printing the object here.
;;; ;; -- WHN 2002-10-19
;;; (error "can't calculate length of cyclic list")))
+
+;;; This is used in constructing arg lists for debugger printing,
+;;; and when needing to print unbound slots in PCL.
+(defstruct (unprintable-object
+ (:constructor make-unprintable-object (string))
+ (:print-object (lambda (x s)
+ (print-unreadable-object (x s)
+ (write-string (unprintable-object-string x) s))))
+ (:copier nil))
+ string)
+
+;;; Used internally, but it would be nice to provide something
+;;; like this for users as well.
+
+#!+sb-thread
+(defmacro define-structure-slot-addressor (name &key structure slot)
+ (let* ((dd (find-defstruct-description structure t))
+ (slotd (when dd (find slot (dd-slots dd) :key #'dsd-name)))
+ (index (when slotd (dsd-index slotd))))
+ (unless index
+ (error "Slot ~S not found in ~S." slot structure))
+ `(progn
+ (declaim (inline ,name))
+ (defun ,name (instance)
+ (declare (type ,structure instance) (optimize speed))
+ (sb!ext:truly-the
+ sb!vm:word
+ (+ (sb!kernel:get-lisp-obj-address instance)
+ (- (* ,(+ sb!vm:instance-slots-offset index) sb!vm:n-word-bytes)
+ sb!vm:instance-pointer-lowtag)))))))
+
+(defmacro compare-and-swap (place old new)
+ "Atomically stores NEW in PLACE if OLD matches the current value of PLACE.
+Two values are considered to match if they are EQ. Returns the previous value
+of PLACE: if the returned value if EQ to OLD, the swap was carried out.
+
+PLACE must be an accessor form whose CAR is one of the following:
+
+ CAR, CDR, FIRST, REST, SYMBOL-PLIST, SYMBOL-VALUE, SVREF
+
+or the name of a DEFSTRUCT created accessor for a slot whose declared type is
+either FIXNUM or T. Results are unspecified if the slot has a declared type
+other then FIXNUM or T.
+
+EXPERIMENTAL: Interface subject to change."
+ (flet ((invalid-place ()
+ (error "Invalid first argument to COMPARE-AND-SWAP: ~S" place)))
+ (unless (consp place)
+ (invalid-place))
+ ;; FIXME: Not the nicest way to do this...
+ (destructuring-bind (op &rest args) place
+ (case op
+ ((car first)
+ `(%compare-and-swap-car (the cons ,@args) ,old ,new))
+ ((cdr rest)
+ `(%compare-and-swap-cdr (the cons ,@args) ,old ,new))
+ (symbol-plist
+ `(%compare-and-swap-symbol-plist (the symbol ,@args) ,old ,new))
+ (symbol-value
+ `(%compare-and-swap-symbol-value (the symbol ,@args) ,old ,new))
+ (svref
+ (let ((vector (car args))
+ (index (cadr args)))
+ (unless (and vector index (not (cddr args)))
+ (invalid-place))
+ (with-unique-names (v)
+ `(let ((,v ,vector))
+ (declare (simple-vector ,v))
+ (%compare-and-swap-svref ,v (%check-bound ,v (length ,v) ,index) ,old ,new)))))
+ (t
+ (let ((dd (info :function :structure-accessor op)))
+ (if dd
+ (let* ((structure (dd-name dd))
+ (slotd (find op (dd-slots dd) :key #'dsd-accessor-name))
+ (index (dsd-index slotd))
+ (type (dsd-type slotd)))
+ (unless (eq t (dsd-raw-type slotd))
+ (error "Cannot use COMPARE-AND-SWAP with structure accessor for a typed slot: ~S"
+ place))
+ (when (dsd-read-only slotd)
+ (error "Cannot use COMPARE-AND-SWAP with structure accessor for a read-only slot: ~S"
+ place))
+ `(truly-the (values ,type &optional)
+ (%compare-and-swap-instance-ref (the ,structure ,@args)
+ ,index
+ (the ,type ,old) (the ,type ,new))))
+ (error "Invalid first argument to COMPARE-AND-SWAP: ~S" place))))))))
+
+(macrolet ((def (name lambda-list ref &optional set)
+ `(defun ,name (,@lambda-list old new)
+ #!+compare-and-swap-vops
+ (declare (ignore ref set))
+ #!+compare-and-swap-vops
+ (,name ,@lambda-list old new)
+ #!-compare-and-swap-vops
+ (let ((current (,ref ,@lambda-list)))
+ (when (eq current old)
+ ,(if set
+ `(,set ,@lambda-list new)
+ `(setf (,ref ,@lambda-list) new)))
+ current))))
+ (def %compare-and-swap-car (cons) car)
+ (def %compare-and-swap-cdr (cons) cdr)
+ (def %compare-and-swap-instance-ref (instance index) %instance-ref %instance-set)
+ (def %compare-and-swap-symbol-plist (symbol) symbol-plist)
+ (def %compare-and-swap-symbol-value (symbol) symbol-value)
+ (def %compare-and-swap-svref (vector index) svref))
+
+(defun call-hooks (kind hooks &key (on-error :error))
+ (dolist (hook hooks)
+ (handler-case
+ (funcall hook)
+ (serious-condition (c)
+ (if (eq :warn on-error)
+ (warn "Problem running ~A hook ~S:~% ~A" kind hook c)
+ (with-simple-restart (continue "Skip this ~A hook." kind)
+ (error "Problem running ~A hook ~S:~% ~A" kind hook c)))))))
projects / sbcl.git / blobdiff