src/pcl/ctor.lisp

   1 ;;;; This file contains the optimization machinery for make-instance.
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5
   6 ;;;; This software is derived from software originally released by
   7 ;;;; Gerd Moellmann.  Copyright and release statements follow.  Later
   8 ;;;; modifications to the software are in the public domain and are
   9 ;;;; provided with absolutely no warranty.  See the COPYING and
  10 ;;;; CREDITS files for more information.
  11
  12 ;;; Copyright (C) 2002 Gerd Moellmann <gerd.moellmann@t-online.de>
  13 ;;; All rights reserved.
  14 ;;;
  15 ;;; Redistribution and use in source and binary forms, with or without
  16 ;;; modification, are permitted provided that the following conditions
  17 ;;; are met:
  18 ;;;
  19 ;;; 1. Redistributions of source code must retain the above copyright
  20 ;;;    notice, this list of conditions and the following disclaimer.
  21 ;;; 2. Redistributions in binary form must reproduce the above copyright
  22 ;;;    notice, this list of conditions and the following disclaimer in the
  23 ;;;    documentation and/or other materials provided with the distribution.
  24 ;;; 3. The name of the author may not be used to endorse or promote
  25 ;;;    products derived from this software without specific prior written
  26 ;;;    permission.
  27 ;;;
  28 ;;; THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  29 ;;; OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  30 ;;; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31 ;;; ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
  32 ;;; LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  33 ;;; CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  34 ;;; OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  35 ;;; BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  36 ;;; LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37 ;;; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  38 ;;; USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  39 ;;; DAMAGE.
  40
  41 ;;; ***************
  42 ;;; Overview  *****
  43 ;;; ***************
  44 ;;;
  45 ;;; Compiler macro for MAKE-INSTANCE, and load-time generation of
  46 ;;; optimized instance constructor functions.
  47 ;;;
  48 ;;; ********************
  49 ;;; Entry Points  ******
  50 ;;; ********************
  51 ;;;
  52 ;;; UPDATE-CTORS must be called when methods are added/removed,
  53 ;;; classes are changed, etc., which affect instance creation.
  54 ;;;
  55 ;;; PRECOMPILE-CTORS can be called to precompile constructor functions
  56 ;;; for classes whose definitions are known at the time the function
  57 ;;; is called.
  58
  59 (in-package "SB-PCL")
  60
  61 ;;; ******************
  62 ;;; Utilities  *******
  63 ;;; ******************
  64
  65 (defun quote-plist-keys (plist)
  66   (loop for (key . more) on plist by #'cddr
  67         if (null more) do
  68           (error "Not a property list: ~S" plist)
  69         else
  70           collect `(quote ,key)
  71           and collect (car more)))
  72
  73 (defun plist-keys (plist &key test)
  74   (loop for (key . more) on plist by #'cddr
  75         if (null more) do
  76           (error "Not a property list: ~S" plist)
  77         else if (or (null test) (funcall test key))
  78           collect key))
  79
  80 (defun plist-values (plist &key test)
  81   (loop for (key . more) on plist by #'cddr
  82         if (null more) do
  83           (error "Not a property list: ~S" plist)
  84         else if (or (null test) (funcall test (car more)))
  85           collect (car more)))
  86
  87 (defun constant-class-arg-p (form)
  88   (and (constantp form)
  89        (let ((constant (constant-form-value form)))
  90          (or (and (symbolp constant)
  91                   (not (null (symbol-package constant))))
  92              (classp form)))))
  93
  94 (defun constant-symbol-p (form)
  95   (and (constantp form)
  96        (let ((constant (constant-form-value form)))
  97          (and (symbolp constant)
  98               (not (null (symbol-package constant)))))))
  99
 100 ;;; Somewhat akin to DEFAULT-INITARGS, but just collecting the defaulted
 101 ;;; initargs for the call.
 102 (defun ctor-default-initkeys (supplied-initargs class-default-initargs)
 103   (loop for (key) in class-default-initargs
 104         when (eq (getf supplied-initargs key '.not-there.) '.not-there.)
 105         collect key))
 106
 107 ;;; Like DEFAULT-INITARGS, but return a list that can be spliced into source,
 108 ;;; instead of a list with values already evaluated.
 109 (defun ctor-default-initargs (supplied-initargs class-default-initargs)
 110   (loop for (key form fun) in class-default-initargs
 111         when (eq (getf supplied-initargs key '.not-there.) '.not-there.)
 112         append (list key (if (constantp form) form `(funcall ,fun)))
 113           into default-initargs
 114         finally
 115           (return (append supplied-initargs default-initargs))))
 116 \f
 117 ;;; *****************
 118 ;;; CTORS   *********
 119 ;;; *****************
 120 ;;;
 121 ;;; Ctors are funcallable instances whose initial function is a
 122 ;;; function computing an optimized constructor function when called.
 123 ;;; When the optimized function is computed, the function of the
 124 ;;; funcallable instance is set to it.
 125 ;;;
 126 (!defstruct-with-alternate-metaclass ctor
 127   :slot-names (function-name class-or-name class initargs safe-p)
 128   :boa-constructor %make-ctor
 129   :superclass-name function
 130   :metaclass-name static-classoid
 131   :metaclass-constructor make-static-classoid
 132   :dd-type funcallable-structure
 133   :runtime-type-checks-p nil)
 134
 135 ;;; List of all defined ctors.
 136 (defvar *all-ctors* ())
 137
 138 (defun make-ctor-parameter-list (ctor)
 139   (plist-values (ctor-initargs ctor) :test (complement #'constantp)))
 140
 141 ;;; Reset CTOR to use a default function that will compute an
 142 ;;; optimized constructor function when called.
 143 (defun install-initial-constructor (ctor &key force-p)
 144   (when (or force-p (ctor-class ctor))
 145     (setf (ctor-class ctor) nil)
 146     (setf (funcallable-instance-fun ctor)
 147           #'(lambda (&rest args)
 148               (install-optimized-constructor ctor)
 149               (apply ctor args)))
 150     (setf (%funcallable-instance-info ctor 1)
 151           (ctor-function-name ctor))))
 152
 153 (defun make-ctor-function-name (class-name initargs safe-code-p)
 154   (list* 'ctor class-name safe-code-p initargs))
 155
 156 ;;; Keep this a separate function for testing.
 157 (defun ensure-ctor (function-name class-name initargs safe-code-p)
 158   (unless (fboundp function-name)
 159     (make-ctor function-name class-name initargs safe-code-p)))
 160
 161 ;;; Keep this a separate function for testing.
 162 (defun make-ctor (function-name class-name initargs safe-p)
 163   (without-package-locks ; for (setf symbol-function)
 164    (let ((ctor (%make-ctor function-name class-name nil initargs safe-p)))
 165      (push ctor *all-ctors*)
 166      (setf (fdefinition function-name) ctor)
 167      (install-initial-constructor ctor :force-p t)
 168      ctor)))
 169 \f
 170 ;;; *****************
 171 ;;; Inline CTOR cache
 172 ;;; *****************
 173 ;;;
 174 ;;; The cache starts out as a list of CTORs, sorted with the most recently
 175 ;;; used CTORs near the head. If it expands too much, we switch to a vector
 176 ;;; with a simple hashing scheme.
 177
 178 ;;; Find CTOR for KEY (which is a class or class name) in a list. If the CTOR
 179 ;;; is in the list but not one of the 4 first ones, return a new list with the
 180 ;;; found CTOR at the head. Thread-safe: the new list shares structure with
 181 ;;; the old, but is not desctructively modified. Returning the old list for
 182 ;;; hits close to the head reduces ping-ponging with multiple threads seeking
 183 ;;; the same list.
 184 (defun find-ctor (key list)
 185   (labels ((walk (tail from-head depth)
 186              (declare (fixnum depth))
 187              (if tail
 188                  (let ((ctor (car tail)))
 189                    (if (eq (ctor-class-or-name ctor) key)
 190                        (if (> depth 3)
 191                            (values ctor
 192                                    (nconc (list ctor) (nreverse from-head) (cdr tail)))
 193                            (values ctor
 194                                    list))
 195                        (walk (cdr tail)
 196                              (cons ctor from-head)
 197                              (logand #xf (1+ depth)))))
 198                  (values nil list))))
 199     (walk list nil 0)))
 200
 201 (declaim (inline sxhash-symbol-or-class))
 202 (defun sxhash-symbol-or-class (x)
 203   (cond ((symbolp x) (sxhash x))
 204         ((std-instance-p x) (std-instance-hash x))
 205         ((fsc-instance-p x) (fsc-instance-hash x))
 206         (t
 207          (bug "Something strange where symbol or class expected."))))
 208
 209 ;;; Max number of CTORs kept in an inline list cache. Once this is
 210 ;;; exceeded we switch to a table.
 211 (defconstant +ctor-list-max-size+ 12)
 212 ;;; Max table size for CTOR cache. If the table fills up at this size
 213 ;;; we keep the same size and drop 50% of the old entries.
 214 (defconstant +ctor-table-max-size+ (expt 2 8))
 215 ;;; Even if there is space in the cache, if we cannot fit a new entry
 216 ;;; with max this number of collisions we expand the table (if possible)
 217 ;;; and rehash.
 218 (defconstant +ctor-table-max-probe-depth+ 5)
 219
 220 (defun make-ctor-table (size)
 221   (declare (index size))
 222   (let ((real-size (power-of-two-ceiling size)))
 223     (if (< real-size +ctor-table-max-size+)
 224         (values (make-array real-size :initial-element nil) nil)
 225         (values (make-array +ctor-table-max-size+ :initial-element nil) t))))
 226
 227 (declaim (inline mix-ctor-hash))
 228 (defun mix-ctor-hash (hash base)
 229   (logand most-positive-fixnum (+ hash base 1)))
 230
 231 (defun put-ctor (ctor table)
 232   (cond ((try-put-ctor ctor table)
 233          (values ctor table))
 234         (t
 235          (expand-ctor-table ctor table))))
 236
 237 ;;; Thread-safe: if two threads write to the same index in parallel, the other
 238 ;;; result is just lost. This is not an issue as the CTORs are used as their
 239 ;;; own keys. If both were EQ, we're good. If non-EQ, the next time the other
 240 ;;; one is needed we just cache it again -- hopefully not getting stomped on
 241 ;;; that time.
 242 (defun try-put-ctor (ctor table)
 243   (declare (simple-vector table) (optimize speed))
 244   (let* ((class (ctor-class-or-name ctor))
 245          (base (sxhash-symbol-or-class class))
 246          (hash base)
 247          (mask (1- (length table))))
 248     (declare (fixnum base hash mask))
 249     (loop repeat +ctor-table-max-probe-depth+
 250           do (let* ((index (logand mask hash))
 251                     (old (aref table index)))
 252                (cond ((and old (neq class (ctor-class-or-name old)))
 253                       (setf hash (mix-ctor-hash hash base)))
 254                      (t
 255                       (setf (aref table index) ctor)
 256                       (return-from try-put-ctor t)))))
 257     ;; Didn't fit, must expand
 258     nil))
 259
 260 (defun get-ctor (class table)
 261   (declare (simple-vector table) (optimize speed))
 262   (let* ((base (sxhash-symbol-or-class class))
 263          (hash base)
 264          (mask (1- (length table))))
 265     (declare (fixnum base hash mask))
 266     (loop repeat +ctor-table-max-probe-depth+
 267           do (let* ((index (logand mask hash))
 268                     (old (aref table index)))
 269                (if (and old (eq class (ctor-class-or-name old)))
 270                    (return-from get-ctor old)
 271                    (setf hash (mix-ctor-hash hash base)))))
 272     ;; Nothing.
 273     nil))
 274
 275 ;;; Thread safe: the old table is read, but if another thread mutates
 276 ;;; it while we're reading we still get a sane result -- either the old
 277 ;;; or the new entry. The new table is locally allocated, so that's ok
 278 ;;; too.
 279 (defun expand-ctor-table (ctor old)
 280   (declare (simple-vector old))
 281   (let* ((old-size (length old))
 282          (new-size (* 2 old-size))
 283          (drop-random-entries nil))
 284     (tagbody
 285      :again
 286        (multiple-value-bind (new max-size-p) (make-ctor-table new-size)
 287          (let ((action (if drop-random-entries
 288                            ;; Same logic as in method caches -- see comment
 289                            ;; there.
 290                            (randomly-punting-lambda (old-ctor)
 291                              (try-put-ctor old-ctor new))
 292                            (lambda (old-ctor)
 293                              (unless (try-put-ctor old-ctor new)
 294                                (if max-size-p
 295                                    (setf drop-random-entries t)
 296                                    (setf new-size (* 2 new-size)))
 297                                (go :again))))))
 298            (aver (try-put-ctor ctor new))
 299            (dotimes (i old-size)
 300              (let ((old-ctor (aref old i)))
 301                (when old-ctor
 302                  (funcall action old-ctor))))
 303            (return-from expand-ctor-table (values ctor new)))))))
 304
 305 (defun ctor-list-to-table (list)
 306   (let ((table (make-ctor-table (length list))))
 307     (dolist (ctor list)
 308       (setf table (nth-value 1 (put-ctor ctor table))))
 309     table))
 310
 311 (defun ctor-for-caching (class-name initargs safe-code-p)
 312   (let ((name (make-ctor-function-name class-name initargs safe-code-p)))
 313     (or (ensure-ctor name class-name initargs safe-code-p)
 314         (fdefinition name))))
 315
 316 (defun ensure-cached-ctor (class-name store initargs safe-code-p)
 317   (if (listp store)
 318       (multiple-value-bind (ctor list) (find-ctor class-name store)
 319         (if ctor
 320             (values ctor list)
 321             (let ((ctor (ctor-for-caching class-name initargs safe-code-p)))
 322               (if (< (length list) +ctor-list-max-size+)
 323                   (values ctor (cons ctor list))
 324                   (values ctor (ctor-list-to-table list))))))
 325       (let ((ctor (get-ctor class-name store)))
 326         (if ctor
 327             (values ctor store)
 328             (put-ctor (ctor-for-caching class-name initargs safe-code-p)
 329                       store)))))
 330 \f
 331 ;;; ***********************************************
 332 ;;; Compile-Time Expansion of MAKE-INSTANCE *******
 333 ;;; ***********************************************
 334
 335 (defvar *compiling-optimized-constructor* nil)
 336
 337 (define-compiler-macro make-instance (&whole form &rest args &environment env)
 338   (declare (ignore args))
 339   ;; Compiling an optimized constructor for a non-standard class means compiling a
 340   ;; lambda with (MAKE-INSTANCE #<SOME-CLASS X> ...) in it -- need
 341   ;; to make sure we don't recurse there.
 342   (or (unless *compiling-optimized-constructor*
 343         (make-instance->constructor-call form (safe-code-p env)))
 344       form))
 345
 346 (defun make-instance->constructor-call (form safe-code-p)
 347   (destructuring-bind (class-arg &rest args) (cdr form)
 348     (flet (;;
 349            ;; Return the name of parameter number I of a constructor
 350            ;; function.
 351            (parameter-name (i)
 352              (let ((ps #(.p0. .p1. .p2. .p3. .p4. .p5.)))
 353                (if (array-in-bounds-p ps i)
 354                    (aref ps i)
 355                    (format-symbol *pcl-package* ".P~D." i))))
 356            ;; Check if CLASS-ARG is a constant symbol.  Give up if
 357            ;; not.
 358            (constant-class-p ()
 359              (and class-arg (constant-class-arg-p class-arg)))
 360            ;; Check if ARGS are suitable for an optimized constructor.
 361            ;; Return NIL from the outer function if not.
 362            (check-args ()
 363              (loop for (key . more) on args by #'cddr do
 364                       (when (or (null more)
 365                                 (not (constant-symbol-p key))
 366                                 (eq :allow-other-keys (constant-form-value key)))
 367                         (return-from make-instance->constructor-call nil)))))
 368       (check-args)
 369       ;; Collect a plist of initargs and constant values/parameter names
 370       ;; in INITARGS.  Collect non-constant initialization forms in
 371       ;; VALUE-FORMS.
 372       (multiple-value-bind (initargs value-forms)
 373           (loop for (key value) on args by #'cddr and i from 0
 374                 collect (constant-form-value key) into initargs
 375                 if (constantp value)
 376                 collect value into initargs
 377                 else
 378                 collect (parameter-name i) into initargs
 379                 and collect value into value-forms
 380                 finally
 381                 (return (values initargs value-forms)))
 382         (if (constant-class-p)
 383             (let* ((class-or-name (constant-form-value class-arg))
 384                    (function-name (make-ctor-function-name class-or-name initargs
 385                                                            safe-code-p)))
 386               ;; Prevent compiler warnings for calling the ctor.
 387               (proclaim-as-fun-name function-name)
 388               (note-name-defined function-name :function)
 389               (when (eq (info :function :where-from function-name) :assumed)
 390                 (setf (info :function :where-from function-name) :defined)
 391                 (when (info :function :assumed-type function-name)
 392                   (setf (info :function :assumed-type function-name) nil)))
 393               ;; Return code constructing a ctor at load time, which, when
 394               ;; called, will set its funcallable instance function to an
 395               ;; optimized constructor function.
 396               `(locally
 397                    (declare (disable-package-locks ,function-name))
 398                  (let ((.x. (load-time-value
 399                              (ensure-ctor ',function-name ',class-or-name ',initargs
 400                                           ',safe-code-p))))
 401                    (declare (ignore .x.))
 402                    ;; ??? check if this is worth it.
 403                    (declare
 404                     (ftype (or (function ,(make-list (length value-forms)
 405                                                      :initial-element t)
 406                                          t)
 407                                (function (&rest t) t))
 408                            ,function-name))
 409                    (funcall (function ,function-name) ,@value-forms))))
 410             (when class-arg
 411               ;; Build an inline cache: a CONS, with the actual cache in the CDR.
 412               `(locally (declare (disable-package-locks .cache. .class-arg. .store. .fun.
 413                                                         make-instance))
 414                  (let* ((.cache. (load-time-value (cons 'ctor-cache nil)))
 415                         (.store. (cdr .cache.))
 416                         (.class-arg. ,class-arg))
 417                    (multiple-value-bind (.fun. .new-store.)
 418                        (ensure-cached-ctor .class-arg. .store. ',initargs ',safe-code-p)
 419                      ;; Thread safe: if multiple threads hit this in paralle, the update
 420                      ;; from the other one is just lost -- no harm done, except for the
 421                      ;; need to redo the work next time.
 422                      (unless (eq .store. .new-store.)
 423                        (setf (cdr .cache.) .new-store.))
 424                      (funcall (truly-the function .fun.) ,@value-forms))))))))))
 425 \f
 426 ;;; **************************************************
 427 ;;; Load-Time Constructor Function Generation  *******
 428 ;;; **************************************************
 429
 430 ;;; The system-supplied primary INITIALIZE-INSTANCE and
 431 ;;; SHARED-INITIALIZE methods.  One cannot initialize these variables
 432 ;;; to the right values here because said functions don't exist yet
 433 ;;; when this file is first loaded.
 434 (defvar *the-system-ii-method* nil)
 435 (defvar *the-system-si-method* nil)
 436
 437 (defun install-optimized-constructor (ctor)
 438   (with-world-lock ()
 439     (let* ((class-or-name (ctor-class-or-name ctor))
 440            (class (if (symbolp class-or-name)
 441                       (find-class class-or-name)
 442                       class-or-name)))
 443       (unless (class-finalized-p class)
 444         (finalize-inheritance class))
 445       ;; We can have a class with an invalid layout here.  Such a class
 446       ;; cannot have a LAYOUT-INVALID of (:FLUSH ...) or (:OBSOLETE
 447       ;; ...), because part of the deal is that those only happen from
 448       ;; FORCE-CACHE-FLUSHES, which create a new valid wrapper for the
 449       ;; class.  An invalid layout of T needs to be flushed, however.
 450       (when (eq (layout-invalid (class-wrapper class)) t)
 451         (%force-cache-flushes class))
 452       (setf (ctor-class ctor) class)
 453       (pushnew ctor (plist-value class 'ctors) :test #'eq)
 454       (setf (funcallable-instance-fun ctor)
 455             (multiple-value-bind (form locations names)
 456                 (constructor-function-form ctor)
 457               (apply
 458                (let ((*compiling-optimized-constructor* t))
 459                  (handler-bind ((compiler-note #'muffle-warning))
 460                    (compile nil `(lambda ,names ,form))))
 461                locations))))))
 462
 463 (defun constructor-function-form (ctor)
 464   (let* ((class (ctor-class ctor))
 465          (proto (class-prototype class))
 466          (make-instance-methods
 467           (compute-applicable-methods #'make-instance (list class)))
 468          (allocate-instance-methods
 469           (compute-applicable-methods #'allocate-instance (list class)))
 470          ;; I stared at this in confusion for a while, thinking
 471          ;; carefully about the possibility of the class prototype not
 472          ;; being of sufficient discrimiating power, given the
 473          ;; possibility of EQL-specialized methods on
 474          ;; INITIALIZE-INSTANCE or SHARED-INITIALIZE.  However, given
 475          ;; that this is a constructor optimization, the user doesn't
 476          ;; yet have the instance to create a method with such an EQL
 477          ;; specializer.
 478          ;;
 479          ;; There remains the (theoretical) possibility of someone
 480          ;; coming along with code of the form
 481          ;;
 482          ;; (defmethod initialize-instance :before ((o foo) ...)
 483          ;;   (eval `(defmethod shared-initialize :before ((o foo) ...) ...)))
 484          ;;
 485          ;; but probably we can afford not to worry about this too
 486          ;; much for now.  -- CSR, 2004-07-12
 487          (ii-methods
 488           (compute-applicable-methods #'initialize-instance (list proto)))
 489          (si-methods
 490           (compute-applicable-methods #'shared-initialize (list proto t)))
 491          (setf-svuc-slots-methods
 492           (loop for slot in (class-slots class)
 493                 collect (compute-applicable-methods
 494                          #'(setf slot-value-using-class)
 495                          (list nil class proto slot))))
 496          (sbuc-slots-methods
 497           (loop for slot in (class-slots class)
 498                 collect (compute-applicable-methods
 499                          #'slot-boundp-using-class
 500                          (list class proto slot)))))
 501     ;; Cannot initialize these variables earlier because the generic
 502     ;; functions don't exist when PCL is built.
 503     (when (null *the-system-si-method*)
 504       (setq *the-system-si-method*
 505             (find-method #'shared-initialize
 506                          () (list *the-class-slot-object* *the-class-t*)))
 507       (setq *the-system-ii-method*
 508             (find-method #'initialize-instance
 509                          () (list *the-class-slot-object*))))
 510     ;; Note that when there are user-defined applicable methods on
 511     ;; MAKE-INSTANCE and/or ALLOCATE-INSTANCE, these will show up
 512     ;; together with the system-defined ones in what
 513     ;; COMPUTE-APPLICABLE-METHODS returns.
 514     (let ((maybe-invalid-initargs
 515            (check-initargs-1
 516             class
 517             (append
 518              (ctor-default-initkeys
 519               (ctor-initargs ctor) (class-default-initargs class))
 520              (plist-keys (ctor-initargs ctor)))
 521             (append ii-methods si-methods) nil nil))
 522           (custom-make-instance
 523            (not (null (cdr make-instance-methods)))))
 524       (if (and (not (structure-class-p class))
 525                (not (condition-class-p class))
 526                (not custom-make-instance)
 527                (null (cdr allocate-instance-methods))
 528                (every (lambda (x)
 529                         (member (slot-definition-allocation x)
 530                                 '(:instance :class)))
 531                       (class-slots class))
 532                (not maybe-invalid-initargs)
 533                (not (around-or-nonstandard-primary-method-p
 534                      ii-methods *the-system-ii-method*))
 535                (not (around-or-nonstandard-primary-method-p
 536                      si-methods *the-system-si-method*))
 537                ;; the instance structure protocol goes through
 538                ;; slot-value(-using-class) and friends (actually just
 539                ;; (SETF SLOT-VALUE-USING-CLASS) and
 540                ;; SLOT-BOUNDP-USING-CLASS), so if there are non-standard
 541                ;; applicable methods we can't shortcircuit them.
 542                (every (lambda (x) (= (length x) 1)) setf-svuc-slots-methods)
 543                (every (lambda (x) (= (length x) 1)) sbuc-slots-methods))
 544           (optimizing-generator ctor ii-methods si-methods)
 545           (fallback-generator ctor ii-methods si-methods
 546                               (or maybe-invalid-initargs custom-make-instance))))))
 547
 548 (defun around-or-nonstandard-primary-method-p
 549     (methods &optional standard-method)
 550   (loop with primary-checked-p = nil
 551         for method in methods
 552         as qualifiers = (if (consp method)
 553                             (early-method-qualifiers method)
 554                             (safe-method-qualifiers method))
 555         when (or (eq :around (car qualifiers))
 556                  (and (null qualifiers)
 557                       (not primary-checked-p)
 558                       (not (null standard-method))
 559                       (not (eq standard-method method))))
 560           return t
 561         when (null qualifiers) do
 562           (setq primary-checked-p t)))
 563
 564 (defun fallback-generator (ctor ii-methods si-methods use-make-instance)
 565   (declare (ignore ii-methods si-methods))
 566   (let ((class (ctor-class ctor))
 567         (lambda-list (make-ctor-parameter-list ctor))
 568         (initargs (quote-plist-keys (ctor-initargs ctor))))
 569     (if use-make-instance
 570         `(lambda ,lambda-list
 571            (declare #.*optimize-speed*)
 572            ;; The CTOR MAKE-INSTANCE optimization checks for
 573            ;; *COMPILING-OPTIMIZED-CONSTRUCTOR* which is bound around compilation of
 574            ;; the constructor, hence avoiding the possibility of endless recursion.
 575            (make-instance ,class ,@initargs))
 576         (let ((defaults (class-default-initargs class)))
 577           (when defaults
 578             (setf initargs (ctor-default-initargs initargs defaults)))
 579           `(lambda ,lambda-list
 580              (declare #.*optimize-speed*)
 581              (fast-make-instance ,class ,@initargs))))))
 582
 583 ;;; Not as good as the real optimizing generator, but faster than going
 584 ;;; via MAKE-INSTANCE: 1 GF call less, and no need to check initargs.
 585 (defun fast-make-instance (class &rest initargs)
 586   (declare #.*optimize-speed*)
 587   (declare (dynamic-extent initargs))
 588   (let ((.instance. (apply #'allocate-instance class initargs)))
 589     (apply #'initialize-instance .instance. initargs)
 590     .instance.))
 591
 592 (defun optimizing-generator (ctor ii-methods si-methods)
 593   (multiple-value-bind (locations names body before-method-p)
 594       (fake-initialization-emf ctor ii-methods si-methods)
 595     (let ((wrapper (class-wrapper (ctor-class ctor))))
 596       (values
 597        `(lambda ,(make-ctor-parameter-list ctor)
 598          (declare #.*optimize-speed*)
 599          (block nil
 600            (when (layout-invalid ,wrapper)
 601              (install-initial-constructor ,ctor)
 602              (return (funcall ,ctor ,@(make-ctor-parameter-list ctor))))
 603            ,(wrap-in-allocate-forms ctor body before-method-p)))
 604        locations
 605        names))))
 606
 607 ;;; Return a form wrapped around BODY that allocates an instance
 608 ;;; constructed by CTOR.  BEFORE-METHOD-P set means we have to run
 609 ;;; before-methods, in which case we initialize instance slots to
 610 ;;; +SLOT-UNBOUND+.  The resulting form binds the local variables
 611 ;;; .INSTANCE. to the instance, and .SLOTS. to the instance's slot
 612 ;;; vector around BODY.
 613 (defun wrap-in-allocate-forms (ctor body before-method-p)
 614   (let* ((class (ctor-class ctor))
 615          (wrapper (class-wrapper class))
 616          (allocation-function (raw-instance-allocator class))
 617          (slots-fetcher (slots-fetcher class)))
 618     (if (eq allocation-function 'allocate-standard-instance)
 619         `(let ((.instance. (%make-standard-instance nil
 620                                                     (get-instance-hash-code)))
 621                (.slots. (make-array
 622                          ,(layout-length wrapper)
 623                          ,@(when before-method-p
 624                              '(:initial-element +slot-unbound+)))))
 625            (setf (std-instance-wrapper .instance.) ,wrapper)
 626            (setf (std-instance-slots .instance.) .slots.)
 627            ,body
 628            .instance.)
 629         `(let* ((.instance. (,allocation-function ,wrapper))
 630                 (.slots. (,slots-fetcher .instance.)))
 631            (declare (ignorable .slots.))
 632            ,body
 633            .instance.))))
 634
 635 ;;; Return a form for invoking METHOD with arguments from ARGS.  As
 636 ;;; can be seen in METHOD-FUNCTION-FROM-FAST-FUNCTION, method
 637 ;;; functions look like (LAMBDA (ARGS NEXT-METHODS) ...).  We could
 638 ;;; call fast method functions directly here, but benchmarks show that
 639 ;;; there's no speed to gain, so lets avoid the hair here.
 640 (defmacro invoke-method (method args)
 641   `(funcall ,(method-function method) ,args ()))
 642
 643 ;;; Return a form that is sort of an effective method comprising all
 644 ;;; calls to INITIALIZE-INSTANCE and SHARED-INITIALIZE that would
 645 ;;; normally have taken place when calling MAKE-INSTANCE.
 646 (defun fake-initialization-emf (ctor ii-methods si-methods)
 647   (multiple-value-bind (ii-around ii-before ii-primary ii-after)
 648       (standard-sort-methods ii-methods)
 649     (declare (ignore ii-primary))
 650     (multiple-value-bind (si-around si-before si-primary si-after)
 651         (standard-sort-methods si-methods)
 652       (declare (ignore si-primary))
 653       (aver (and (null ii-around) (null si-around)))
 654       (let ((initargs (ctor-initargs ctor)))
 655         (multiple-value-bind (locations names bindings vars defaulting-initargs body)
 656             (slot-init-forms ctor (or ii-before si-before))
 657         (values
 658          locations
 659          names
 660          `(let ,bindings
 661            (declare (ignorable ,@vars))
 662            (let (,@(when (or ii-before ii-after)
 663                      `((.ii-args.
 664                         (list .instance. ,@(quote-plist-keys initargs) ,@defaulting-initargs))))
 665                  ,@(when (or si-before si-after)
 666                      `((.si-args.
 667                         (list .instance. t ,@(quote-plist-keys initargs) ,@defaulting-initargs)))))
 668             ,@(loop for method in ii-before
 669                     collect `(invoke-method ,method .ii-args.))
 670             ,@(loop for method in si-before
 671                     collect `(invoke-method ,method .si-args.))
 672             ,@body
 673             ,@(loop for method in si-after
 674                     collect `(invoke-method ,method .si-args.))
 675             ,@(loop for method in ii-after
 676                     collect `(invoke-method ,method .ii-args.))))
 677          (or ii-before si-before)))))))
 678
 679 ;;; Return four values from APPLICABLE-METHODS: around methods, before
 680 ;;; methods, the applicable primary method, and applicable after
 681 ;;; methods.  Before and after methods are sorted in the order they
 682 ;;; must be called.
 683 (defun standard-sort-methods (applicable-methods)
 684   (loop for method in applicable-methods
 685         as qualifiers = (if (consp method)
 686                             (early-method-qualifiers method)
 687                             (safe-method-qualifiers method))
 688         if (null qualifiers)
 689           collect method into primary
 690         else if (eq :around (car qualifiers))
 691           collect method into around
 692         else if (eq :after (car qualifiers))
 693           collect method into after
 694         else if (eq :before (car qualifiers))
 695           collect method into before
 696         finally
 697           (return (values around before (first primary) (reverse after)))))
 698
 699 (defmacro with-type-checked ((type safe-p) &body body)
 700   (if safe-p
 701       ;; To handle FUNCTION types reasonable, we use SAFETY 3 and
 702       ;; THE instead of e.g. CHECK-TYPE.
 703       `(locally
 704            (declare (optimize (safety 3)))
 705          (the ,type (progn ,@body)))
 706       `(progn ,@body)))
 707
 708 ;;; Return as multiple values bindings for default initialization
 709 ;;; arguments, variable names, defaulting initargs and a body for
 710 ;;; initializing instance and class slots of an object costructed by
 711 ;;; CTOR.  The variable .SLOTS. is assumed to bound to the instance's
 712 ;;; slot vector.  BEFORE-METHOD-P T means before-methods will be
 713 ;;; called, which means that 1) other code will initialize instance
 714 ;;; slots to +SLOT-UNBOUND+ before the before-methods are run, and
 715 ;;; that we have to check if these before-methods have set slots.
 716 (defun slot-init-forms (ctor before-method-p)
 717   (let* ((class (ctor-class ctor))
 718          (initargs (ctor-initargs ctor))
 719          (initkeys (plist-keys initargs))
 720          (safe-p (ctor-safe-p ctor))
 721          (slot-vector
 722           (make-array (layout-length (class-wrapper class))
 723                       :initial-element nil))
 724          (class-inits ())
 725          (default-inits ())
 726          (defaulting-initargs ())
 727          (default-initargs (class-default-initargs class))
 728          (initarg-locations
 729           (compute-initarg-locations
 730            class (append initkeys (mapcar #'car default-initargs)))))
 731     (labels ((initarg-locations (initarg)
 732                (cdr (assoc initarg initarg-locations :test #'eq)))
 733              (initializedp (location)
 734                (cond
 735                  ((consp location)
 736                   (assoc location class-inits :test #'eq))
 737                  ((integerp location)
 738                   (not (null (aref slot-vector location))))
 739                  (t (bug "Weird location in ~S" 'slot-init-forms))))
 740              (class-init (location kind val type)
 741                (aver (consp location))
 742                (unless (initializedp location)
 743                  (push (list location kind val type) class-inits)))
 744              (instance-init (location kind val type)
 745                (aver (integerp location))
 746                (unless (initializedp location)
 747                  (setf (aref slot-vector location) (list kind val type))))
 748              (default-init-var-name (i)
 749                (let ((ps #(.d0. .d1. .d2. .d3. .d4. .d5.)))
 750                  (if (array-in-bounds-p ps i)
 751                      (aref ps i)
 752                      (format-symbol *pcl-package* ".D~D." i))))
 753              (location-var-name (i)
 754                (let ((ls #(.l0. .l1. .l2. .l3. .l4. .l5.)))
 755                  (if (array-in-bounds-p ls i)
 756                      (aref ls i)
 757                      (format-symbol *pcl-package* ".L~D." i)))))
 758       ;; Loop over supplied initargs and values and record which
 759       ;; instance and class slots they initialize.
 760       (loop for (key value) on initargs by #'cddr
 761             as kind = (if (constantp value) 'constant 'param)
 762             as locations = (initarg-locations key)
 763             do (loop for (location . type) in locations
 764                      do (if (consp location)
 765                             (class-init location kind value type)
 766                             (instance-init location kind value type))))
 767       ;; Loop over default initargs of the class, recording
 768       ;; initializations of slots that have not been initialized
 769       ;; above.  Default initargs which are not in the supplied
 770       ;; initargs are treated as if they were appended to supplied
 771       ;; initargs, that is, their values must be evaluated even
 772       ;; if not actually used for initializing a slot.
 773       (loop for (key initform initfn) in default-initargs and i from 0
 774             unless (member key initkeys :test #'eq)
 775             do (let* ((kind (if (constantp initform) 'constant 'var))
 776                       (init (if (eq kind 'var) initfn initform)))
 777                  (ecase kind
 778                    (constant
 779                     (push (list 'quote key) defaulting-initargs)
 780                     (push initform defaulting-initargs))
 781                    (var
 782                     (push (list 'quote key) defaulting-initargs)
 783                     (push (default-init-var-name i) defaulting-initargs)))
 784               (when (eq kind 'var)
 785                 (let ((init-var (default-init-var-name i)))
 786                   (setq init init-var)
 787                   (push (cons init-var initfn) default-inits)))
 788               (loop for (location . type) in (initarg-locations key)
 789                     do (if (consp location)
 790                            (class-init location kind init type)
 791                            (instance-init location kind init type)))))
 792       ;; Loop over all slots of the class, filling in the rest from
 793       ;; slot initforms.
 794       (loop for slotd in (class-slots class)
 795             as location = (slot-definition-location slotd)
 796             as type = (slot-definition-type slotd)
 797             as allocation = (slot-definition-allocation slotd)
 798             as initfn = (slot-definition-initfunction slotd)
 799             as initform = (slot-definition-initform slotd) do
 800               (unless (or (eq allocation :class)
 801                           (null initfn)
 802                           (initializedp location))
 803                 (if (constantp initform)
 804                     (instance-init location 'initform initform type)
 805                     (instance-init location 'initform/initfn initfn type))))
 806       ;; Generate the forms for initializing instance and class slots.
 807       (let ((instance-init-forms
 808              (loop for slot-entry across slot-vector and i from 0
 809                    as (kind value type) = slot-entry collect
 810                      (ecase kind
 811                        ((nil)
 812                         (unless before-method-p
 813                           `(setf (clos-slots-ref .slots. ,i) +slot-unbound+)))
 814                        ((param var)
 815                         `(setf (clos-slots-ref .slots. ,i)
 816                                (with-type-checked (,type ,safe-p)
 817                                    ,value)))
 818                        (initfn
 819                         `(setf (clos-slots-ref .slots. ,i)
 820                                (with-type-checked (,type ,safe-p)
 821                                  (funcall ,value))))
 822                        (initform/initfn
 823                         (if before-method-p
 824                             `(when (eq (clos-slots-ref .slots. ,i)
 825                                        +slot-unbound+)
 826                                (setf (clos-slots-ref .slots. ,i)
 827                                      (with-type-checked (,type ,safe-p)
 828                                        (funcall ,value))))
 829                             `(setf (clos-slots-ref .slots. ,i)
 830                                    (with-type-checked (,type ,safe-p)
 831                                      (funcall ,value)))))
 832                        (initform
 833                         (if before-method-p
 834                             `(when (eq (clos-slots-ref .slots. ,i)
 835                                        +slot-unbound+)
 836                                (setf (clos-slots-ref .slots. ,i)
 837                                      (with-type-checked (,type ,safe-p)
 838                                        ',(constant-form-value value))))
 839                             `(setf (clos-slots-ref .slots. ,i)
 840                                    (with-type-checked (,type ,safe-p)
 841                                      ',(constant-form-value value)))))
 842                        (constant
 843                         `(setf (clos-slots-ref .slots. ,i)
 844                                (with-type-checked (,type ,safe-p)
 845                                  ',(constant-form-value value))))))))
 846         ;; we are not allowed to modify QUOTEd locations, so we can't
 847         ;; generate code like (setf (cdr ',location) arg).  Instead,
 848         ;; we have to do (setf (cdr .L0.) arg) and arrange for .L0. to
 849         ;; be bound to the location.
 850         (multiple-value-bind (names locations class-init-forms)
 851             (loop for (location kind value type) in class-inits
 852                   for i upfrom 0
 853                   for name = (location-var-name i)
 854                   collect name into names
 855                   collect location into locations
 856                   collect `(setf (cdr ,name)
 857                                  (with-type-checked (,type ,safe-p)
 858                                    ,(case kind
 859                                           (constant `',(constant-form-value value))
 860                                           ((param var) `,value)
 861                                           (initfn `(funcall ,value)))))
 862                   into class-init-forms
 863                   finally (return (values names locations class-init-forms)))
 864           (multiple-value-bind (vars bindings)
 865               (loop for (var . initfn) in (nreverse default-inits)
 866                     collect var into vars
 867                     collect `(,var (funcall ,initfn)) into bindings
 868                     finally (return (values vars bindings)))
 869             (values locations names
 870                     bindings vars
 871                     (nreverse defaulting-initargs)
 872                     `(,@(delete nil instance-init-forms)
 873                       ,@class-init-forms))))))))
 874
 875 ;;; Return an alist of lists (KEY (LOCATION . TYPE-SPECIFIER) ...)
 876 ;;; telling, for each key in INITKEYS, which locations the initarg
 877 ;;; initializes and the associated type with the location.  CLASS is
 878 ;;; the class of the instance being initialized.
 879 (defun compute-initarg-locations (class initkeys)
 880   (loop with slots = (class-slots class)
 881         for key in initkeys collect
 882           (loop for slot in slots
 883                 if (memq key (slot-definition-initargs slot))
 884                   collect (cons (slot-definition-location slot)
 885                                 (slot-definition-type slot))
 886                           into locations
 887                 else
 888                   collect slot into remaining-slots
 889                 finally
 890                   (setq slots remaining-slots)
 891                   (return (cons key locations)))))
 892
 893 \f
 894 ;;; *******************************
 895 ;;; External Entry Points  ********
 896 ;;; *******************************
 897
 898 (defun update-ctors (reason &key class name generic-function method)
 899   (labels ((reset (class &optional ri-cache-p (ctorsp t))
 900              (when ctorsp
 901                (dolist (ctor (plist-value class 'ctors))
 902                  (install-initial-constructor ctor)))
 903              (when ri-cache-p
 904                (setf (plist-value class 'ri-initargs) ()))
 905              (dolist (subclass (class-direct-subclasses class))
 906                (reset subclass ri-cache-p ctorsp))))
 907     (ecase reason
 908       ;; CLASS must have been specified.
 909       (finalize-inheritance
 910        (reset class t))
 911       ;; NAME must have been specified.
 912       (setf-find-class
 913        (loop for ctor in *all-ctors*
 914              when (eq (ctor-class-or-name ctor) name) do
 915              (when (ctor-class ctor)
 916                (reset (ctor-class ctor)))
 917              (loop-finish)))
 918       ;; GENERIC-FUNCTION and METHOD must have been specified.
 919       ((add-method remove-method)
 920        (flet ((class-of-1st-method-param (method)
 921                 (type-class (first (method-specializers method)))))
 922          (case (generic-function-name generic-function)
 923            ((make-instance allocate-instance
 924              initialize-instance shared-initialize)
 925             (reset (class-of-1st-method-param method) t t))
 926            ((reinitialize-instance)
 927             (reset (class-of-1st-method-param method) t nil))
 928            (t (when (or (eq (generic-function-name generic-function)
 929                             'slot-boundp-using-class)
 930                         (equal (generic-function-name generic-function)
 931                                '(setf slot-value-using-class)))
 932                 ;; this looks awfully expensive, but given that one
 933                 ;; can specialize on the SLOTD argument, nothing is
 934                 ;; safe.  -- CSR, 2004-07-12
 935                 (reset (find-class 'standard-object))))))))))
 936
 937 (defun precompile-ctors ()
 938   (dolist (ctor *all-ctors*)
 939     (when (null (ctor-class ctor))
 940       (let ((class (find-class (ctor-class-or-name ctor) nil)))
 941         (when (and class (class-finalized-p class))
 942           (install-optimized-constructor ctor))))))
 943
 944 (defun check-ri-initargs (instance initargs)
 945   (let* ((class (class-of instance))
 946          (keys (plist-keys initargs))
 947          (cached (assoc keys (plist-value class 'ri-initargs)
 948                         :test #'equal))
 949          (invalid-keys
 950           (if (consp cached)
 951               (cdr cached)
 952               (let ((invalid
 953                      ;; FIXME: give CHECK-INITARGS-1 and friends a
 954                      ;; more mnemonic name and (possibly) a nicer,
 955                      ;; more orthogonal interface.
 956                      (check-initargs-1
 957                       class initargs
 958                       (list (list* 'reinitialize-instance instance initargs)
 959                             (list* 'shared-initialize instance nil initargs))
 960                       t nil)))
 961                 (setf (plist-value class 'ri-initargs)
 962                       (acons keys invalid cached))
 963                 invalid))))
 964     (when invalid-keys
 965       (error 'initarg-error :class class :initargs invalid-keys))))
 966
 967 ;;; end of ctor.lisp