X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fpcl%2Fstd-class.lisp;h=9f2b8c1af2f9f2beac3740377345effa65ad24cd;hb=f73aadf04d841e0f1bfede4c11a13c4ba5c4e264;hp=8721509ae53a30d4d32824c899fa1a949e1d0cb2;hpb=562e48a2bd3467121e24214110e535c841fbb622;p=sbcl.git diff --git a/src/pcl/std-class.lisp b/src/pcl/std-class.lisp index 8721509..9f2b8c1 100644 --- a/src/pcl/std-class.lisp +++ b/src/pcl/std-class.lisp @@ -173,15 +173,40 @@ ;;; 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-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-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)))) 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)) @@ -189,15 +214,19 @@ (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. @@ -215,12 +244,17 @@ (let* ((object (specializer-object specializer)) (table (specializer-method-table specializer)) (entry (gethash object table))) + ;; This table is shared between multiple specializers, but + ;; no worries as (at least for the time being) our hash-tables + ;; are thread safe. (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))) method)) (defmethod remove-direct-method ((specializer specializer-with-object) @@ -228,8 +262,11 @@ (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 +279,12 @@ (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) @@ -1319,7 +1357,7 @@ (type-of (obsolete-structure-datum condition)))))) (defun obsolete-instance-trap (owrapper nwrapper instance) - (if (not (pcl-instance-p 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))