1 ;;;; the basics of the PCL wrapper cache mechanism
3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from software originally released by Xerox
7 ;;;; Corporation. Copyright and release statements follow. Later modifications
8 ;;;; to the software are in the public domain and are provided with
9 ;;;; absolutely no warranty. See the COPYING and CREDITS files for more
12 ;;;; copyright information from original PCL sources:
14 ;;;; Copyright (c) 1985, 1986, 1987, 1988, 1989, 1990 Xerox Corporation.
15 ;;;; All rights reserved.
17 ;;;; Use and copying of this software and preparation of derivative works based
18 ;;;; upon this software are permitted. Any distribution of this software or
19 ;;;; derivative works must comply with all applicable United States export
22 ;;;; This software is made available AS IS, and Xerox Corporation makes no
23 ;;;; warranty about the software, its performance or its conformity to any
28 ;;; FIXME: SB-PCL should probably USE-PACKAGE SB-KERNEL, since SB-PCL
29 ;;; is built on SB-KERNEL, and in the absence of USE-PACKAGE, it ends
30 ;;; up using a thundering herd of explicit prefixes to get to
31 ;;; SB-KERNEL symbols. Using the SB-INT and SB-EXT packages as well
32 ;;; would help reduce prefixing and make it more natural to reuse
33 ;;; things (ONCE-ONLY, *KEYWORD-PACKAGE*..) used in the main body of
34 ;;; the system. However, that would cause a conflict between the
35 ;;; SB-ITERATE:ITERATE macro and the SB-INT:ITERATE macro. (This could
36 ;;; be resolved by renaming SB-INT:ITERATE to SB-INT:NAMED-LET, or
37 ;;; with more gruntwork by punting the SB-ITERATE package and
38 ;;; replacing calls to SB-ITERATE:ITERATE with calls to CL:LOOP.
40 ;;; * Do some sort of automated check for overlap of symbols to make
41 ;;; sure there wouldn't be any other clashes.
42 ;;; * Rename SB-INT:ITERATE to SB-INT:NAMED-LET.
43 ;;; * Make SB-PCL use SB-INT and SB-EXT.
44 ;;; * Grep for SB-INT: and SB-EXT: prefixes in the pcl/ directory
47 ;;; The caching algorithm implemented:
49 ;;; << put a paper here >>
51 ;;; For now, understand that as far as most of this code goes, a cache
52 ;;; has two important properties. The first is the number of wrappers
53 ;;; used as keys in each cache line. Throughout this code, this value
54 ;;; is always called NKEYS. The second is whether or not the cache
55 ;;; lines of a cache store a value. Throughout this code, this always
58 ;;; Depending on these values, there are three kinds of caches.
60 ;;; NKEYS = 1, VALUEP = NIL
62 ;;; In this kind of cache, each line is 1 word long. No cache locking
63 ;;; is needed since all read's in the cache are a single value.
64 ;;; Nevertheless line 0 (location 0) is reserved, to ensure that
65 ;;; invalid wrappers will not get a first probe hit.
67 ;;; To keep the code simpler, a cache lock count does appear in
68 ;;; location 0 of these caches, that count is incremented whenever
69 ;;; data is written to the cache. But, the actual lookup code (see
70 ;;; make-dlap) doesn't need to do locking when reading the cache.
72 ;;; NKEYS = 1, VALUEP = T
74 ;;; In this kind of cache, each line is 2 words long. Cache locking
75 ;;; must be done to ensure the synchronization of cache reads. Line 0
76 ;;; of the cache (location 0) is reserved for the cache lock count.
77 ;;; Location 1 of the cache is unused (in effect wasted).
81 ;;; In this kind of cache, the 0 word of the cache holds the lock
82 ;;; count. The 1 word of the cache is line 0. Line 0 of these caches
85 ;;; This is done because in this sort of cache, the overhead of doing
86 ;;; the cache probe is high enough that the 1+ required to offset the
87 ;;; location is not a significant cost. In addition, because of the
88 ;;; larger line sizes, the space that would be wasted by reserving
89 ;;; line 0 to hold the lock count is more significant.
93 ;;; A cache is essentially just a vector. The use of the individual
94 ;;; `words' in the vector depends on particular properties of the
95 ;;; cache as described above.
97 ;;; This defines an abstraction for caches in terms of their most
98 ;;; obvious implementation as simple vectors. But, please notice that
99 ;;; part of the implementation of this abstraction, is the function
100 ;;; lap-out-cache-ref. This means that most port-specific
101 ;;; modifications to the implementation of caches will require
102 ;;; corresponding port-specific modifications to the lap code
104 (defmacro cache-vector-ref (cache-vector location)
105 `(svref (the simple-vector ,cache-vector)
106 (sb-ext:truly-the fixnum ,location)))
108 (defmacro cache-vector-size (cache-vector)
109 `(array-dimension (the simple-vector ,cache-vector) 0))
111 (defun allocate-cache-vector (size)
112 (make-array size :adjustable nil))
114 (defmacro cache-vector-lock-count (cache-vector)
115 `(cache-vector-ref ,cache-vector 0))
117 (defun flush-cache-vector-internal (cache-vector)
119 (fill (the simple-vector cache-vector) nil)
120 (setf (cache-vector-lock-count cache-vector) 0))
123 (defmacro modify-cache (cache-vector &body body)
125 (multiple-value-prog1
127 (let ((old-count (cache-vector-lock-count ,cache-vector)))
128 (declare (fixnum old-count))
129 (setf (cache-vector-lock-count ,cache-vector)
130 (if (= old-count most-positive-fixnum)
131 1 (the fixnum (1+ old-count))))))))
133 (deftype field-type ()
134 '(mod #.sb-kernel:layout-clos-hash-length))
136 (eval-when (:compile-toplevel :load-toplevel :execute)
137 (defun power-of-two-ceiling (x)
139 ;;(expt 2 (ceiling (log x 2)))
140 (the fixnum (ash 1 (integer-length (1- x)))))
143 (defconstant +nkeys-limit+ 256)
145 (defstruct (cache (:constructor make-cache ())
146 (:copier copy-cache-internal))
148 (nkeys 1 :type (integer 1 #.+nkeys-limit+))
149 (valuep nil :type (member nil t))
150 (nlines 0 :type fixnum)
151 (field 0 :type field-type)
152 (limit-fn #'default-limit-fn :type function)
153 (mask 0 :type fixnum)
154 (size 0 :type fixnum)
155 (line-size 1 :type (integer 1 #.(power-of-two-ceiling (1+ +nkeys-limit+))))
156 (max-location 0 :type fixnum)
157 (vector #() :type simple-vector)
158 (overflow nil :type list))
160 #-sb-fluid (declaim (sb-ext:freeze-type cache))
162 (defmacro cache-lock-count (cache)
163 `(cache-vector-lock-count (cache-vector ,cache)))
165 ;;; some facilities for allocation and freeing caches as they are needed
167 ;;; This is done on the assumption that a better port of PCL will
168 ;;; arrange to cons these all in the same static area. Given that, the
169 ;;; fact that PCL tries to reuse them should be a win.
171 (defvar *free-cache-vectors* (make-hash-table :size 16 :test 'eql))
173 ;;; Return a cache that has had FLUSH-CACHE-VECTOR-INTERNAL called on
174 ;;; it. This returns a cache of exactly the size requested, it won't
175 ;;; ever return a larger cache.
176 (defun get-cache-vector (size)
177 (let ((entry (gethash size *free-cache-vectors*)))
180 (setf (gethash size *free-cache-vectors*) (cons 0 nil))
181 (get-cache-vector size))
184 (flush-cache-vector-internal (allocate-cache-vector size)))
186 (let ((cache (cdr entry)))
187 (setf (cdr entry) (cache-vector-ref cache 0))
188 (flush-cache-vector-internal cache)))))))
190 (defun free-cache-vector (cache-vector)
191 (let ((entry (gethash (cache-vector-size cache-vector) *free-cache-vectors*)))
195 "attempt to free a cache-vector not allocated by GET-CACHE-VECTOR")
196 (let ((thread (cdr entry)))
197 (loop (unless thread (return))
198 (when (eq thread cache-vector)
199 (error "freeing a cache twice"))
200 (setq thread (cache-vector-ref thread 0)))
201 (flush-cache-vector-internal cache-vector) ; to help the GC
202 (setf (cache-vector-ref cache-vector 0) (cdr entry))
203 (setf (cdr entry) cache-vector)
206 ;;; This is just for debugging and analysis. It shows the state of the
207 ;;; free cache resource.
209 (defun show-free-cache-vectors ()
211 (maphash #'(lambda (s e) (push (list s e) elements)) *free-cache-vectors*)
212 (setq elements (sort elements #'< :key #'car))
214 (let* ((size (car e))
216 (allocated (car entry))
219 (loop (when (null head) (return t))
220 (setq head (cache-vector-ref head 0))
223 "~&There ~4D are caches of size ~4D. (~D free ~3D%)"
227 (floor (* 100 (/ free (float allocated)))))))))
229 ;;;; wrapper cache numbers
231 ;;; The constant WRAPPER-CACHE-NUMBER-ADDS-OK controls the number of
232 ;;; non-zero bits wrapper cache numbers will have.
234 ;;; The value of this constant is the number of wrapper cache numbers
235 ;;; which can be added and still be certain the result will be a
236 ;;; fixnum. This is used by all the code that computes primary cache
237 ;;; locations from multiple wrappers.
239 ;;; The value of this constant is used to derive the next two which
240 ;;; are the forms of this constant which it is more convenient for the
241 ;;; runtime code to use.
242 (defconstant wrapper-cache-number-length
243 (integer-length sb-kernel:layout-clos-hash-max))
244 (defconstant wrapper-cache-number-mask sb-kernel:layout-clos-hash-max)
245 (defconstant wrapper-cache-number-adds-ok
246 (truncate most-positive-fixnum sb-kernel:layout-clos-hash-max))
248 ;;;; wrappers themselves
250 ;;; This caching algorithm requires that wrappers have more than one
251 ;;; wrapper cache number. You should think of these multiple numbers
252 ;;; as being in columns. That is, for a given cache, the same column
253 ;;; of wrapper cache numbers will be used.
255 ;;; If at some point the cache distribution of a cache gets bad, the
256 ;;; cache can be rehashed by switching to a different column.
258 ;;; The columns are referred to by field number which is that number
259 ;;; which, when used as a second argument to wrapper-ref, will return
260 ;;; that column of wrapper cache number.
262 ;;; This code is written to allow flexibility as to how many wrapper
263 ;;; cache numbers will be in each wrapper, and where they will be
264 ;;; located. It is also set up to allow port specific modifications to
265 ;;; `pack' the wrapper cache numbers on machines where the addressing
266 ;;; modes make that a good idea.
268 ;;; In SBCL, as in CMU CL, we want to do type checking as early as
269 ;;; possible; structures help this. The structures are hard-wired to
270 ;;; have a fixed number of cache hash values, and that number must
271 ;;; correspond to the number of cache lines we use.
272 (defconstant wrapper-cache-number-vector-length
273 sb-kernel:layout-clos-hash-length)
275 (unless (boundp '*the-class-t*)
276 (setq *the-class-t* nil))
278 ;;; Note that for SBCL, as for CMU CL, the WRAPPER of a built-in or
279 ;;; structure class will be some other kind of SB-KERNEL:LAYOUT, but
280 ;;; this shouldn't matter, since the only two slots that WRAPPER adds
281 ;;; are meaningless in those cases.
283 (:include sb-kernel:layout
284 ;; KLUDGE: In CMU CL, the initialization default
285 ;; for LAYOUT-INVALID was NIL. In SBCL, that has
286 ;; changed to :UNINITIALIZED, but PCL code might
287 ;; still expect NIL for the initialization
288 ;; default of WRAPPER-INVALID. Instead of trying
289 ;; to find out, I just overrode the LAYOUT
290 ;; default here. -- WHN 19991204
292 (:conc-name %wrapper-)
293 (:constructor make-wrapper-internal))
294 (instance-slots-layout nil :type list)
295 (class-slots nil :type list))
296 #-sb-fluid (declaim (sb-ext:freeze-type wrapper))
298 (defmacro wrapper-class (wrapper)
299 `(sb-kernel:class-pcl-class (sb-kernel:layout-class ,wrapper)))
300 (defmacro wrapper-no-of-instance-slots (wrapper)
301 `(sb-kernel:layout-length ,wrapper))
303 ;;; WRAPPER-STATE returns T (not generalized boolean, but T exactly)
304 ;;; iff the wrapper is valid. Any other return value denotes some
305 ;;; invalid state. Special conventions have been set up for certain
306 ;;; invalid states, e.g. obsoleteness or flushedness, but I (WHN
307 ;;; 19991204) haven't been motivated to reverse engineer them from the
308 ;;; code and document them here.
310 ;;; FIXME: This is awkward and unmnemonic. There is a function
311 ;;; (INVALID-WRAPPER-P) to test this return result abstractly for
312 ;;; invalidness but it's not called consistently; the functions that
313 ;;; need to know whether a wrapper is invalid often test (EQ
314 ;;; (WRAPPER-STATE X) T), ick. It would be good to use the abstract
315 ;;; test instead. It would probably be even better to switch the sense
316 ;;; of the WRAPPER-STATE function, renaming it to WRAPPER-INVALID and
317 ;;; making it synonymous with LAYOUT-INVALID. Then the
318 ;;; INVALID-WRAPPER-P function would become trivial and would go away
319 ;;; (replaced with WRAPPER-INVALID), since all the various invalid
320 ;;; wrapper states would become generalized boolean "true" values. --
322 #-sb-fluid (declaim (inline wrapper-state (setf wrapper-state)))
323 (defun wrapper-state (wrapper)
324 (let ((invalid (sb-kernel:layout-invalid wrapper)))
325 (cond ((null invalid)
328 ;; some non-PCL object. INVALID is probably :INVALID. We
329 ;; should arguably compute the new wrapper here instead of
330 ;; returning NIL, but we don't bother, since
331 ;; OBSOLETE-INSTANCE-TRAP can't use it.
335 (defun (setf wrapper-state) (new-value wrapper)
336 (setf (sb-kernel:layout-invalid wrapper)
337 (if (eq new-value 't)
341 (defmacro wrapper-instance-slots-layout (wrapper)
342 `(%wrapper-instance-slots-layout ,wrapper))
343 (defmacro wrapper-class-slots (wrapper)
344 `(%wrapper-class-slots ,wrapper))
345 (defmacro wrapper-cache-number-vector (x) x)
347 ;;; This is called in BRAID when we are making wrappers for classes
348 ;;; whose slots are not initialized yet, and which may be built-in
349 ;;; classes. We pass in the class name in addition to the class.
350 (defun boot-make-wrapper (length name &optional class)
351 (let ((found (cl:find-class name nil)))
354 (unless (sb-kernel:class-pcl-class found)
355 (setf (sb-kernel:class-pcl-class found) class))
356 (assert (eq (sb-kernel:class-pcl-class found) class))
357 (let ((layout (sb-kernel:class-layout found)))
361 (make-wrapper-internal
363 :class (sb-kernel:make-standard-class :name name :pcl-class class))))))
365 ;;; The following variable may be set to a standard-class that has
366 ;;; already been created by the lisp code and which is to be redefined
367 ;;; by PCL. This allows standard-classes to be defined and used for
368 ;;; type testing and dispatch before PCL is loaded.
369 (defvar *pcl-class-boot* nil)
371 ;;; In SBCL, as in CMU CL, the layouts (a.k.a wrappers) for built-in
372 ;;; and structure classes already exist when PCL is initialized, so we
373 ;;; don't necessarily always make a wrapper. Also, we help maintain
374 ;;; the mapping between cl:class and pcl::class objects.
375 (defun make-wrapper (length class)
377 ((typep class 'std-class)
378 (make-wrapper-internal
381 (let ((owrap (class-wrapper class)))
383 (sb-kernel:layout-class owrap))
384 ((*subtypep (class-of class)
385 *the-class-standard-class*)
386 (cond ((and *pcl-class-boot*
387 (eq (slot-value class 'name) *pcl-class-boot*))
388 (let ((found (cl:find-class (slot-value class 'name))))
389 (unless (sb-kernel:class-pcl-class found)
390 (setf (sb-kernel:class-pcl-class found) class))
391 (assert (eq (sb-kernel:class-pcl-class found) class))
394 (sb-kernel:make-standard-class :pcl-class class))))
396 (sb-kernel:make-random-pcl-class :pcl-class class))))))
398 (let* ((found (cl:find-class (slot-value class 'name)))
399 (layout (sb-kernel:class-layout found)))
400 (unless (sb-kernel:class-pcl-class found)
401 (setf (sb-kernel:class-pcl-class found) class))
402 (assert (eq (sb-kernel:class-pcl-class found) class))
406 ;;; FIXME: The immediately following macros could become inline functions.
408 (defmacro first-wrapper-cache-number-index ()
411 (defmacro next-wrapper-cache-number-index (field-number)
412 `(and (< ,field-number #.(1- wrapper-cache-number-vector-length))
415 (defmacro cache-number-vector-ref (cnv n)
416 `(wrapper-cache-number-vector-ref ,cnv ,n))
418 (defmacro wrapper-cache-number-vector-ref (wrapper n)
419 `(sb-kernel:layout-clos-hash ,wrapper ,n))
421 (defmacro class-no-of-instance-slots (class)
422 `(wrapper-no-of-instance-slots (class-wrapper ,class)))
424 (defmacro wrapper-class* (wrapper)
425 `(let ((wrapper ,wrapper))
426 (or (wrapper-class wrapper)
427 (find-structure-class
428 (cl:class-name (sb-kernel:layout-class wrapper))))))
430 ;;; The wrapper cache machinery provides general mechanism for
431 ;;; trapping on the next access to any instance of a given class. This
432 ;;; mechanism is used to implement the updating of instances when the
433 ;;; class is redefined (MAKE-INSTANCES-OBSOLETE). The same mechanism
434 ;;; is also used to update generic function caches when there is a
435 ;;; change to the superclasses of a class.
437 ;;; Basically, a given wrapper can be valid or invalid. If it is
438 ;;; invalid, it means that any attempt to do a wrapper cache lookup
439 ;;; using the wrapper should trap. Also, methods on
440 ;;; SLOT-VALUE-USING-CLASS check the wrapper validity as well. This is
441 ;;; done by calling CHECK-WRAPPER-VALIDITY.
443 ;;; FIXME: could become inline function
444 (defmacro invalid-wrapper-p (wrapper)
445 `(neq (wrapper-state ,wrapper) 't))
447 (defvar *previous-nwrappers* (make-hash-table))
449 (defun invalidate-wrapper (owrapper state nwrapper)
452 (let ((new-previous ()))
453 ;; First off, a previous call to INVALIDATE-WRAPPER may have
454 ;; recorded OWRAPPER as an NWRAPPER to update to. Since
455 ;; OWRAPPER is about to be invalid, it no longer makes sense to
458 ;; We go back and change the previously invalidated wrappers so
459 ;; that they will now update directly to NWRAPPER. This
460 ;; corresponds to a kind of transitivity of wrapper updates.
461 (dolist (previous (gethash owrapper *previous-nwrappers*))
462 (when (eq state ':obsolete)
463 (setf (car previous) ':obsolete))
464 (setf (cadr previous) nwrapper)
465 (push previous new-previous))
467 (let ((ocnv (wrapper-cache-number-vector owrapper)))
468 (dotimes (i sb-kernel:layout-clos-hash-length)
469 (setf (cache-number-vector-ref ocnv i) 0)))
470 (push (setf (wrapper-state owrapper) (list state nwrapper))
473 (setf (gethash owrapper *previous-nwrappers*) ()
474 (gethash nwrapper *previous-nwrappers*) new-previous)))))
476 (defun check-wrapper-validity (instance)
477 (let* ((owrapper (wrapper-of instance))
478 (state (wrapper-state owrapper)))
484 (flush-cache-trap owrapper (cadr state) instance))
486 (obsolete-instance-trap owrapper (cadr state) instance)))))
487 ;; This little bit of error checking is superfluous. It only
488 ;; checks to see whether the person who implemented the trap
489 ;; handling screwed up. Since that person is hacking
490 ;; internal PCL code, and is not a user, this should be
491 ;; needless. Also, since this directly slows down instance
492 ;; update and generic function cache refilling, feel free to
493 ;; take it out sometime soon.
495 ;; FIXME: We probably need to add a #+SB-PARANOID feature to
496 ;; make stuff like this optional. Until then, it stays in.
497 (cond ((neq nwrapper (wrapper-of instance))
498 (error "wrapper returned from trap not wrapper of instance"))
499 ((invalid-wrapper-p nwrapper)
500 (error "wrapper returned from trap invalid")))
503 (defmacro check-wrapper-validity1 (object)
504 (let ((owrapper (gensym)))
505 `(let ((,owrapper (sb-kernel:layout-of object)))
506 (if (sb-kernel:layout-invalid ,owrapper)
507 (check-wrapper-validity ,object)
510 (defvar *free-caches* nil)
512 (defun get-cache (nkeys valuep limit-fn nlines)
513 (let ((cache (or (without-interrupts (pop *free-caches*)) (make-cache))))
514 (declare (type cache cache))
515 (multiple-value-bind (cache-mask actual-size line-size nlines)
516 (compute-cache-parameters nkeys valuep nlines)
517 (setf (cache-nkeys cache) nkeys
518 (cache-valuep cache) valuep
519 (cache-nlines cache) nlines
520 (cache-field cache) (first-wrapper-cache-number-index)
521 (cache-limit-fn cache) limit-fn
522 (cache-mask cache) cache-mask
523 (cache-size cache) actual-size
524 (cache-line-size cache) line-size
525 (cache-max-location cache) (let ((line (1- nlines)))
528 (1+ (* line line-size))))
529 (cache-vector cache) (get-cache-vector actual-size)
530 (cache-overflow cache) nil)
533 (defun get-cache-from-cache (old-cache new-nlines
534 &optional (new-field (first-wrapper-cache-number-index)))
535 (let ((nkeys (cache-nkeys old-cache))
536 (valuep (cache-valuep old-cache))
537 (cache (or (without-interrupts (pop *free-caches*)) (make-cache))))
538 (declare (type cache cache))
539 (multiple-value-bind (cache-mask actual-size line-size nlines)
540 (if (= new-nlines (cache-nlines old-cache))
541 (values (cache-mask old-cache) (cache-size old-cache)
542 (cache-line-size old-cache) (cache-nlines old-cache))
543 (compute-cache-parameters nkeys valuep new-nlines))
544 (setf (cache-owner cache) (cache-owner old-cache)
545 (cache-nkeys cache) nkeys
546 (cache-valuep cache) valuep
547 (cache-nlines cache) nlines
548 (cache-field cache) new-field
549 (cache-limit-fn cache) (cache-limit-fn old-cache)
550 (cache-mask cache) cache-mask
551 (cache-size cache) actual-size
552 (cache-line-size cache) line-size
553 (cache-max-location cache) (let ((line (1- nlines)))
556 (1+ (* line line-size))))
557 (cache-vector cache) (get-cache-vector actual-size)
558 (cache-overflow cache) nil)
561 (defun copy-cache (old-cache)
562 (let* ((new-cache (copy-cache-internal old-cache))
563 (size (cache-size old-cache))
564 (old-vector (cache-vector old-cache))
565 (new-vector (get-cache-vector size)))
566 (declare (simple-vector old-vector new-vector))
567 (dotimes-fixnum (i size)
568 (setf (svref new-vector i) (svref old-vector i)))
569 (setf (cache-vector new-cache) new-vector)
572 (defun free-cache (cache)
573 (free-cache-vector (cache-vector cache))
574 (setf (cache-vector cache) #())
575 (setf (cache-owner cache) nil)
576 (push cache *free-caches*)
579 (defun compute-line-size (x)
580 (power-of-two-ceiling x))
582 (defun compute-cache-parameters (nkeys valuep nlines-or-cache-vector)
583 ;;(declare (values cache-mask actual-size line-size nlines))
584 (declare (fixnum nkeys))
586 (let* ((line-size (if valuep 2 1))
587 (cache-size (if (typep nlines-or-cache-vector 'fixnum)
591 (power-of-two-ceiling
592 nlines-or-cache-vector))))
593 (cache-vector-size nlines-or-cache-vector))))
594 (declare (fixnum line-size cache-size))
595 (values (logxor (the fixnum (1- cache-size)) (the fixnum (1- line-size)))
598 (the fixnum (floor cache-size line-size))))
599 (let* ((line-size (power-of-two-ceiling (if valuep (1+ nkeys) nkeys)))
600 (cache-size (if (typep nlines-or-cache-vector 'fixnum)
604 (power-of-two-ceiling
605 nlines-or-cache-vector))))
606 (1- (cache-vector-size nlines-or-cache-vector)))))
607 (declare (fixnum line-size cache-size))
608 (values (logxor (the fixnum (1- cache-size)) (the fixnum (1- line-size)))
609 (the fixnum (1+ cache-size))
611 (the fixnum (floor cache-size line-size))))))
613 ;;; the various implementations of computing a primary cache location from
614 ;;; wrappers. Because some implementations of this must run fast there are
615 ;;; several implementations of the same algorithm.
617 ;;; The algorithm is:
619 ;;; SUM over the wrapper cache numbers,
620 ;;; ENSURING that the result is a fixnum
621 ;;; MASK the result against the mask argument.
623 ;;; COMPUTE-PRIMARY-CACHE-LOCATION
625 ;;; The basic functional version. This is used by the cache miss code to
626 ;;; compute the primary location of an entry.
627 (defun compute-primary-cache-location (field mask wrappers)
629 (declare (type field-type field) (fixnum mask))
630 (if (not (listp wrappers))
632 (the fixnum (wrapper-cache-number-vector-ref wrappers field)))
633 (let ((location 0) (i 0))
634 (declare (fixnum location i))
635 (dolist (wrapper wrappers)
636 ;; First add the cache number of this wrapper to location.
637 (let ((wrapper-cache-number (wrapper-cache-number-vector-ref wrapper
639 (declare (fixnum wrapper-cache-number))
640 (if (zerop wrapper-cache-number)
641 (return-from compute-primary-cache-location 0)
643 (the fixnum (+ location wrapper-cache-number)))))
644 ;; Then, if we are working with lots of wrappers, deal with
645 ;; the wrapper-cache-number-mask stuff.
646 (when (and (not (zerop i))
647 (zerop (mod i wrapper-cache-number-adds-ok)))
649 (logand location wrapper-cache-number-mask)))
651 (the fixnum (1+ (logand mask location))))))
653 ;;; COMPUTE-PRIMARY-CACHE-LOCATION-FROM-LOCATION
655 ;;; This version is called on a cache line. It fetches the wrappers
656 ;;; from the cache line and determines the primary location. Various
657 ;;; parts of the cache filling code call this to determine whether it
658 ;;; is appropriate to displace a given cache entry.
660 ;;; If this comes across a wrapper whose CACHE-NO is 0, it returns the
661 ;;; symbol invalid to suggest to its caller that it would be provident
662 ;;; to blow away the cache line in question.
663 (defun compute-primary-cache-location-from-location (to-cache
666 (from-cache to-cache))
667 (declare (type cache to-cache from-cache) (fixnum from-location))
669 (cache-vector (cache-vector from-cache))
670 (field (cache-field to-cache))
671 (mask (cache-mask to-cache))
672 (nkeys (cache-nkeys to-cache)))
673 (declare (type field-type field) (fixnum result mask nkeys)
674 (simple-vector cache-vector))
675 (dotimes-fixnum (i nkeys)
676 (let* ((wrapper (cache-vector-ref cache-vector (+ i from-location)))
677 (wcn (wrapper-cache-number-vector-ref wrapper field)))
678 (declare (fixnum wcn))
679 (setq result (+ result wcn)))
680 (when (and (not (zerop i))
681 (zerop (mod i wrapper-cache-number-adds-ok)))
682 (setq result (logand result wrapper-cache-number-mask))))
685 (the fixnum (1+ (logand mask result))))))
687 ;;; NIL means nothing so far, no actual arg info has NILs
689 ;;; CLASS seen all sorts of metaclasses
690 ;;; (specifically, more than one of the next 4 values)
691 ;;; T means everything so far is the class T
692 ;;; STANDARD-CLASS seen only standard classes
693 ;;; BUILT-IN-CLASS seen only built in classes
694 ;;; STRUCTURE-CLASS seen only structure classes
695 (defun raise-metatype (metatype new-specializer)
696 (let ((slot (find-class 'slot-class))
697 (std (find-class 'std-class))
698 (standard (find-class 'standard-class))
699 (fsc (find-class 'funcallable-standard-class))
700 (structure (find-class 'structure-class))
701 (built-in (find-class 'built-in-class)))
702 (flet ((specializer->metatype (x)
703 (let ((meta-specializer
704 (if (eq *boot-state* 'complete)
705 (class-of (specializer-class x))
707 (cond ((eq x *the-class-t*) t)
708 ((*subtypep meta-specializer std)
710 ((*subtypep meta-specializer standard)
712 ((*subtypep meta-specializer fsc)
714 ((*subtypep meta-specializer structure)
716 ((*subtypep meta-specializer built-in)
718 ((*subtypep meta-specializer slot)
720 (t (error "PCL cannot handle the specializer ~S (meta-specializer ~S)."
722 meta-specializer))))))
723 ;; We implement the following table. The notation is
724 ;; that X and Y are distinct meta specializer names.
726 ;; NIL <anything> ===> <anything>
729 (let ((new-metatype (specializer->metatype new-specializer)))
730 (cond ((eq new-metatype 'slot-instance) 'class)
731 ((null metatype) new-metatype)
732 ((eq metatype new-metatype) new-metatype)
735 (defmacro with-dfun-wrappers ((args metatypes)
736 (dfun-wrappers invalid-wrapper-p
737 &optional wrappers classes types)
738 invalid-arguments-form
740 `(let* ((args-tail ,args) (,invalid-wrapper-p nil) (invalid-arguments-p nil)
741 (,dfun-wrappers nil) (dfun-wrappers-tail nil)
743 `((wrappers-rev nil) (types-rev nil) (classes-rev nil))))
744 (dolist (mt ,metatypes)
746 (setq invalid-arguments-p t)
748 (let* ((arg (pop args-tail))
751 `((class *the-class-t*)
754 (setq wrapper (wrapper-of arg))
755 (when (invalid-wrapper-p wrapper)
756 (setq ,invalid-wrapper-p t)
757 (setq wrapper (check-wrapper-validity arg)))
758 (cond ((null ,dfun-wrappers)
759 (setq ,dfun-wrappers wrapper))
760 ((not (consp ,dfun-wrappers))
761 (setq dfun-wrappers-tail (list wrapper))
762 (setq ,dfun-wrappers (cons ,dfun-wrappers dfun-wrappers-tail)))
764 (let ((new-dfun-wrappers-tail (list wrapper)))
765 (setf (cdr dfun-wrappers-tail) new-dfun-wrappers-tail)
766 (setf dfun-wrappers-tail new-dfun-wrappers-tail))))
768 `((setq class (wrapper-class* wrapper))
769 (setq type `(class-eq ,class)))))
771 `((push wrapper wrappers-rev)
772 (push class classes-rev)
773 (push type types-rev)))))
774 (if invalid-arguments-p
775 ,invalid-arguments-form
776 (let* (,@(when wrappers
777 `((,wrappers (nreverse wrappers-rev))
778 (,classes (nreverse classes-rev))
779 (,types (mapcar #'(lambda (class)
784 ;;;; some support stuff for getting a hold of symbols that we need when
785 ;;;; building the discriminator codes. It's OK for these to be interned
786 ;;;; symbols because we don't capture any user code in the scope in which
787 ;;;; these symbols are bound.
789 (defvar *dfun-arg-symbols* '(.ARG0. .ARG1. .ARG2. .ARG3.))
791 (defun dfun-arg-symbol (arg-number)
792 (or (nth arg-number (the list *dfun-arg-symbols*))
793 (intern (format nil ".ARG~A." arg-number) *pcl-package*)))
795 (defvar *slot-vector-symbols* '(.SLOTS0. .SLOTS1. .SLOTS2. .SLOTS3.))
797 (defun slot-vector-symbol (arg-number)
798 (or (nth arg-number (the list *slot-vector-symbols*))
799 (intern (format nil ".SLOTS~A." arg-number) *pcl-package*)))
801 (defun make-dfun-lambda-list (metatypes applyp)
802 (gathering1 (collecting)
803 (iterate ((i (interval :from 0))
804 (s (list-elements metatypes)))
806 (gather1 (dfun-arg-symbol i)))
809 (gather1 '.dfun-rest-arg.))))
811 (defun make-dlap-lambda-list (metatypes applyp)
812 (gathering1 (collecting)
813 (iterate ((i (interval :from 0))
814 (s (list-elements metatypes)))
816 (gather1 (dfun-arg-symbol i)))
820 (defun make-emf-call (metatypes applyp fn-variable &optional emf-type)
822 (gathering1 (collecting)
823 (iterate ((i (interval :from 0))
824 (s (list-elements metatypes)))
826 (gather1 (dfun-arg-symbol i))))))
827 `(,(if (eq emf-type 'fast-method-call)
828 'invoke-effective-method-function-fast
829 'invoke-effective-method-function)
830 ,fn-variable ,applyp ,@required ,@(when applyp `(.dfun-rest-arg.)))))
832 (defun make-dfun-call (metatypes applyp fn-variable)
834 (gathering1 (collecting)
835 (iterate ((i (interval :from 0))
836 (s (list-elements metatypes)))
838 (gather1 (dfun-arg-symbol i))))))
840 `(function-apply ,fn-variable ,@required .dfun-rest-arg.)
841 `(function-funcall ,fn-variable ,@required))))
843 (defun make-dfun-arg-list (metatypes applyp)
845 (gathering1 (collecting)
846 (iterate ((i (interval :from 0))
847 (s (list-elements metatypes)))
849 (gather1 (dfun-arg-symbol i))))))
851 `(list* ,@required .dfun-rest-arg.)
852 `(list ,@required))))
854 (defun make-fast-method-call-lambda-list (metatypes applyp)
855 (gathering1 (collecting)
857 (gather1 '.next-method-call.)
858 (iterate ((i (interval :from 0))
859 (s (list-elements metatypes)))
861 (gather1 (dfun-arg-symbol i)))
863 (gather1 '.dfun-rest-arg.))))
865 ;;;; a comment from some PCL implementor:
866 ;;;; Its too bad Common Lisp compilers freak out when you have a
867 ;;;; DEFUN with a lot of LABELS in it. If I could do that I could
868 ;;;; make this code much easier to read and work with.
870 ;;;; In the absence of that, the following little macro makes the
871 ;;;; code that follows a little bit more reasonable. I would like to
872 ;;;; add that having to practically write my own compiler in order to
873 ;;;; get just this simple thing is something of a drag.
875 ;;;; KLUDGE: Maybe we could actually implement this as LABELS now,
876 ;;;; since AFAIK CMU CL doesn't freak out when you have a DEFUN with a
877 ;;;; lot of LABELS in it (and if it does we can fix it instead of
878 ;;;; working around it). -- WHN 19991204
880 (eval-when (:compile-toplevel :load-toplevel :execute)
884 ;;; FIXME: should be undefined after bootstrapping
885 (defparameter *local-cache-functions*
887 (nkeys () (cache-nkeys .cache.))
888 (line-size () (cache-line-size .cache.))
889 (vector () (cache-vector .cache.))
890 (valuep () (cache-valuep .cache.))
891 (nlines () (cache-nlines .cache.))
892 (max-location () (cache-max-location .cache.))
893 (limit-fn () (cache-limit-fn .cache.))
894 (size () (cache-size .cache.))
895 (mask () (cache-mask .cache.))
896 (field () (cache-field .cache.))
897 (overflow () (cache-overflow .cache.))
899 ;; Return T IFF this cache location is reserved. The only time
900 ;; this is true is for line number 0 of an nkeys=1 cache.
901 (line-reserved-p (line)
902 (declare (fixnum line))
905 (location-reserved-p (location)
906 (declare (fixnum location))
909 ;; Given a line number, return the cache location. This is the
910 ;; value that is the second argument to cache-vector-ref. Basically,
911 ;; this deals with the offset of nkeys>1 caches and multiplies
913 (line-location (line)
914 (declare (fixnum line))
915 (when (line-reserved-p line)
916 (error "Line is reserved."))
918 (the fixnum (* line (line-size)))
919 (the fixnum (1+ (the fixnum (* line (line-size)))))))
921 ;; Given a cache location, return the line. This is the inverse
923 (location-line (location)
924 (declare (fixnum location))
926 (floor location (line-size))
927 (floor (the fixnum (1- location)) (line-size))))
929 ;; Given a line number, return the wrappers stored at that line.
930 ;; As usual, if nkeys=1, this returns a single value. Only when
931 ;; nkeys>1 does it return a list. An error is signalled if the
933 (line-wrappers (line)
934 (declare (fixnum line))
935 (when (line-reserved-p line) (error "Line is reserved."))
936 (location-wrappers (line-location line)))
937 (location-wrappers (location) ; avoid multiplies caused by line-location
938 (declare (fixnum location))
940 (cache-vector-ref (vector) location)
941 (let ((list (make-list (nkeys)))
943 (declare (simple-vector vector))
944 (dotimes-fixnum (i (nkeys) list)
945 (setf (nth i list) (cache-vector-ref vector (+ location i)))))))
947 ;; Given a line number, return true IFF the line's
948 ;; wrappers are the same as wrappers.
949 (line-matches-wrappers-p (line wrappers)
950 (declare (fixnum line))
951 (and (not (line-reserved-p line))
952 (location-matches-wrappers-p (line-location line) wrappers)))
953 (location-matches-wrappers-p (loc wrappers) ; must not be reserved
954 (declare (fixnum loc))
955 (let ((cache-vector (vector)))
956 (declare (simple-vector cache-vector))
958 (eq wrappers (cache-vector-ref cache-vector loc))
959 (dotimes-fixnum (i (nkeys) t)
960 (unless (eq (pop wrappers)
961 (cache-vector-ref cache-vector (+ loc i)))
964 ;; Given a line number, return the value stored at that line.
965 ;; If valuep is NIL, this returns NIL. As with line-wrappers,
966 ;; an error is signalled if the line is reserved.
968 (declare (fixnum line))
969 (when (line-reserved-p line) (error "Line is reserved."))
970 (location-value (line-location line)))
971 (location-value (loc)
972 (declare (fixnum loc))
974 (cache-vector-ref (vector) (+ loc (nkeys)))))
976 ;; Given a line number, return true iff that line has data in
977 ;; it. The state of the wrappers stored in the line is not
978 ;; checked. An error is signalled if line is reserved.
980 (when (line-reserved-p line) (error "Line is reserved."))
981 (not (null (cache-vector-ref (vector) (line-location line)))))
983 ;; Given a line number, return true iff the line is full and
984 ;; there are no invalid wrappers in the line, and the line's
985 ;; wrappers are different from wrappers.
986 ;; An error is signalled if the line is reserved.
987 (line-valid-p (line wrappers)
988 (declare (fixnum line))
989 (when (line-reserved-p line) (error "Line is reserved."))
990 (location-valid-p (line-location line) wrappers))
991 (location-valid-p (loc wrappers)
992 (declare (fixnum loc))
993 (let ((cache-vector (vector))
994 (wrappers-mismatch-p (null wrappers)))
995 (declare (simple-vector cache-vector))
996 (dotimes-fixnum (i (nkeys) wrappers-mismatch-p)
997 (let ((wrapper (cache-vector-ref cache-vector (+ loc i))))
998 (when (or (null wrapper)
999 (invalid-wrapper-p wrapper))
1001 (unless (and wrappers
1003 (if (consp wrappers) (pop wrappers) wrappers)))
1004 (setq wrappers-mismatch-p t))))))
1006 ;; how many unreserved lines separate line-1 and line-2
1007 (line-separation (line-1 line-2)
1008 (declare (fixnum line-1 line-2))
1009 (let ((diff (the fixnum (- line-2 line-1))))
1010 (declare (fixnum diff))
1012 (setq diff (+ diff (nlines)))
1013 (when (line-reserved-p 0)
1014 (setq diff (1- diff))))
1017 ;; Given a cache line, get the next cache line. This will not
1018 ;; return a reserved line.
1020 (declare (fixnum line))
1021 (if (= line (the fixnum (1- (nlines))))
1022 (if (line-reserved-p 0) 1 0)
1023 (the fixnum (1+ line))))
1024 (next-location (loc)
1025 (declare (fixnum loc))
1026 (if (= loc (max-location))
1030 (the fixnum (+ loc (line-size)))))
1032 ;; Given a line which has a valid entry in it, this will return
1033 ;; the primary cache line of the wrappers in that line. We just
1034 ;; call COMPUTE-PRIMARY-CACHE-LOCATION-FROM-LOCATION, this is an
1035 ;; easier packaging up of the call to it.
1036 (line-primary (line)
1037 (declare (fixnum line))
1038 (location-line (line-primary-location line)))
1039 (line-primary-location (line)
1040 (declare (fixnum line))
1041 (compute-primary-cache-location-from-location
1042 (cache) (line-location line)))))
1044 (defmacro with-local-cache-functions ((cache) &body body)
1045 `(let ((.cache. ,cache))
1046 (declare (type cache .cache.))
1047 (macrolet ,(mapcar #'(lambda (fn)
1048 `(,(car fn) ,(cadr fn)
1049 `(let (,,@(mapcar #'(lambda (var)
1053 *local-cache-functions*)
1058 ;;; Here is where we actually fill, recache and expand caches.
1060 ;;; The functions FILL-CACHE and PROBE-CACHE are the ONLY external
1061 ;;; entrypoints into this code.
1063 ;;; FILL-CACHE returns 1 value: a new cache
1065 ;;; a wrapper field number
1068 ;;; an absolute cache size (the size of the actual vector)
1069 ;;; It tries to re-adjust the cache every time it makes a new fill.
1070 ;;; The intuition here is that we want uniformity in the number of
1071 ;;; probes needed to find an entry. Furthermore, adjusting has the
1072 ;;; nice property of throwing out any entries that are invalid.
1073 (defvar *cache-expand-threshold* 1.25)
1075 (defun fill-cache (cache wrappers value &optional free-cache-p)
1077 ;; FILL-CACHE won't return if WRAPPERS is nil, might as well check..
1079 (error "fill-cache: WRAPPERS arg is NIL!"))
1081 (or (fill-cache-p nil cache wrappers value)
1082 (and (< (ceiling (* (cache-count cache) 1.25))
1083 (if (= (cache-nkeys cache) 1)
1084 (1- (cache-nlines cache))
1085 (cache-nlines cache)))
1086 (adjust-cache cache wrappers value free-cache-p))
1087 (expand-cache cache wrappers value free-cache-p)))
1089 (defvar *check-cache-p* nil)
1091 (defmacro maybe-check-cache (cache)
1093 (when *check-cache-p*
1094 (check-cache ,cache))
1097 (defun check-cache (cache)
1098 (with-local-cache-functions (cache)
1099 (let ((location (if (= (nkeys) 1) 0 1))
1100 (limit (funcall (limit-fn) (nlines))))
1101 (dotimes-fixnum (i (nlines) cache)
1102 (when (and (not (location-reserved-p location))
1104 (let* ((home-loc (compute-primary-cache-location-from-location
1106 (home (location-line (if (location-reserved-p home-loc)
1107 (next-location home-loc)
1109 (sep (when home (line-separation home i))))
1110 (when (and sep (> sep limit))
1111 (error "bad cache ~S ~@
1112 value at location ~D: ~D lines from its home. The limit is ~D."
1113 cache location sep limit))))
1114 (setq location (next-location location))))))
1116 (defun probe-cache (cache wrappers &optional default limit-fn)
1117 ;;(declare (values value))
1119 ;; FIXME: This and another earlier test on a WRAPPERS arg can
1120 ;; be compact assertoids.
1121 (error "WRAPPERS arg is NIL!"))
1122 (with-local-cache-functions (cache)
1123 (let* ((location (compute-primary-cache-location (field) (mask) wrappers))
1124 (limit (funcall (or limit-fn (limit-fn)) (nlines))))
1125 (declare (fixnum location limit))
1126 (when (location-reserved-p location)
1127 (setq location (next-location location)))
1128 (dotimes-fixnum (i (1+ limit))
1129 (when (location-matches-wrappers-p location wrappers)
1130 (return-from probe-cache (or (not (valuep))
1131 (location-value location))))
1132 (setq location (next-location location)))
1133 (dolist (entry (overflow))
1134 (when (equal (car entry) wrappers)
1135 (return-from probe-cache (or (not (valuep))
1139 (defun map-cache (function cache &optional set-p)
1140 (with-local-cache-functions (cache)
1141 (let ((set-p (and set-p (valuep))))
1142 (dotimes-fixnum (i (nlines) cache)
1143 (unless (or (line-reserved-p i) (not (line-valid-p i nil)))
1144 (let ((value (funcall function (line-wrappers i) (line-value i))))
1146 (setf (cache-vector-ref (vector) (+ (line-location i) (nkeys)))
1148 (dolist (entry (overflow))
1149 (let ((value (funcall function (car entry) (cdr entry))))
1151 (setf (cdr entry) value))))))
1154 (defun cache-count (cache)
1155 (with-local-cache-functions (cache)
1157 (declare (fixnum count))
1158 (dotimes-fixnum (i (nlines) count)
1159 (unless (line-reserved-p i)
1160 (when (line-full-p i)
1163 (defun entry-in-cache-p (cache wrappers value)
1164 (declare (ignore value))
1165 (with-local-cache-functions (cache)
1166 (dotimes-fixnum (i (nlines))
1167 (unless (line-reserved-p i)
1168 (when (equal (line-wrappers i) wrappers)
1171 ;;; returns T or NIL
1172 (defun fill-cache-p (forcep cache wrappers value)
1173 (with-local-cache-functions (cache)
1174 (let* ((location (compute-primary-cache-location (field) (mask) wrappers))
1175 (primary (location-line location)))
1176 (declare (fixnum location primary))
1177 (multiple-value-bind (free emptyp)
1178 (find-free-cache-line primary cache wrappers)
1179 (when (or forcep emptyp)
1181 (push (cons (line-wrappers free) (line-value free))
1182 (cache-overflow cache)))
1183 ;;(fill-line free wrappers value)
1185 (declare (fixnum line))
1186 (when (line-reserved-p line)
1187 (error "attempt to fill a reserved line"))
1188 (let ((loc (line-location line))
1189 (cache-vector (vector)))
1190 (declare (fixnum loc) (simple-vector cache-vector))
1191 (cond ((= (nkeys) 1)
1192 (setf (cache-vector-ref cache-vector loc) wrappers)
1194 (setf (cache-vector-ref cache-vector (1+ loc)) value)))
1197 (declare (fixnum i))
1198 (dolist (w wrappers)
1199 (setf (cache-vector-ref cache-vector (+ loc i)) w)
1200 (setq i (the fixnum (1+ i)))))
1202 (setf (cache-vector-ref cache-vector (+ loc (nkeys)))
1204 (maybe-check-cache cache))))))))
1206 (defun fill-cache-from-cache-p (forcep cache from-cache from-line)
1207 (declare (fixnum from-line))
1208 (with-local-cache-functions (cache)
1209 (let ((primary (location-line
1210 (compute-primary-cache-location-from-location
1211 cache (line-location from-line) from-cache))))
1212 (declare (fixnum primary))
1213 (multiple-value-bind (free emptyp)
1214 (find-free-cache-line primary cache)
1215 (when (or forcep emptyp)
1217 (push (cons (line-wrappers free) (line-value free))
1218 (cache-overflow cache)))
1219 ;;(transfer-line from-cache-vector from-line cache-vector free)
1220 (let ((from-cache-vector (cache-vector from-cache))
1221 (to-cache-vector (vector))
1223 (declare (fixnum to-line))
1224 (if (line-reserved-p to-line)
1225 (error "transferring something into a reserved cache line")
1226 (let ((from-loc (line-location from-line))
1227 (to-loc (line-location to-line)))
1228 (declare (fixnum from-loc to-loc))
1229 (modify-cache to-cache-vector
1230 (dotimes-fixnum (i (line-size))
1231 (setf (cache-vector-ref to-cache-vector
1233 (cache-vector-ref from-cache-vector
1234 (+ from-loc i)))))))
1235 (maybe-check-cache cache)))))))
1237 ;;; Returns NIL or (values <field> <cache-vector>)
1239 ;;; This is only called when it isn't possible to put the entry in the
1240 ;;; cache the easy way. That is, this function assumes that
1241 ;;; FILL-CACHE-P has been called as returned NIL.
1243 ;;; If this returns NIL, it means that it wasn't possible to find a
1244 ;;; wrapper field for which all of the entries could be put in the
1245 ;;; cache (within the limit).
1246 (defun adjust-cache (cache wrappers value free-old-cache-p)
1247 (with-local-cache-functions (cache)
1248 (let ((ncache (get-cache-from-cache cache (nlines) (field))))
1249 (do ((nfield (cache-field ncache) (next-wrapper-cache-number-index nfield)))
1250 ((null nfield) (free-cache ncache) nil)
1251 (setf (cache-field ncache) nfield)
1252 (labels ((try-one-fill-from-line (line)
1253 (fill-cache-from-cache-p nil ncache cache line))
1254 (try-one-fill (wrappers value)
1255 (fill-cache-p nil ncache wrappers value)))
1256 (if (and (dotimes-fixnum (i (nlines) t)
1257 (when (and (null (line-reserved-p i))
1258 (line-valid-p i wrappers))
1259 (unless (try-one-fill-from-line i) (return nil))))
1260 (dolist (wrappers+value (cache-overflow cache) t)
1261 (unless (try-one-fill (car wrappers+value) (cdr wrappers+value))
1263 (try-one-fill wrappers value))
1264 (progn (when free-old-cache-p (free-cache cache))
1265 (return (maybe-check-cache ncache)))
1266 (flush-cache-vector-internal (cache-vector ncache))))))))
1268 ;;; returns: (values <cache>)
1269 (defun expand-cache (cache wrappers value free-old-cache-p)
1270 ;;(declare (values cache))
1271 (with-local-cache-functions (cache)
1272 (let ((ncache (get-cache-from-cache cache (* (nlines) 2))))
1273 (labels ((do-one-fill-from-line (line)
1274 (unless (fill-cache-from-cache-p nil ncache cache line)
1275 (do-one-fill (line-wrappers line) (line-value line))))
1276 (do-one-fill (wrappers value)
1277 (setq ncache (or (adjust-cache ncache wrappers value t)
1278 (fill-cache-p t ncache wrappers value))))
1279 (try-one-fill (wrappers value)
1280 (fill-cache-p nil ncache wrappers value)))
1281 (dotimes-fixnum (i (nlines))
1282 (when (and (null (line-reserved-p i))
1283 (line-valid-p i wrappers))
1284 (do-one-fill-from-line i)))
1285 (dolist (wrappers+value (cache-overflow cache))
1286 (unless (try-one-fill (car wrappers+value) (cdr wrappers+value))
1287 (do-one-fill (car wrappers+value) (cdr wrappers+value))))
1288 (unless (try-one-fill wrappers value)
1289 (do-one-fill wrappers value))
1290 (when free-old-cache-p (free-cache cache))
1291 (maybe-check-cache ncache)))))
1293 ;;; This is the heart of the cache filling mechanism. It implements
1294 ;;; the decisions about where entries are placed.
1296 ;;; Find a line in the cache at which a new entry can be inserted.
1299 ;;; <empty?> is <line> in fact empty?
1300 (defun find-free-cache-line (primary cache &optional wrappers)
1301 ;;(declare (values line empty?))
1302 (declare (fixnum primary))
1303 (with-local-cache-functions (cache)
1304 (when (line-reserved-p primary) (setq primary (next-line primary)))
1305 (let ((limit (funcall (limit-fn) (nlines)))
1308 (p primary) (s primary))
1309 (declare (fixnum p s limit))
1312 ;; Try to find a free line starting at <s>. <p> is the
1313 ;; primary line of the entry we are finding a free
1314 ;; line for, it is used to compute the separations.
1315 (do* ((line s (next-line line))
1316 (nsep (line-separation p s) (1+ nsep)))
1318 (declare (fixnum line nsep))
1319 (when (null (line-valid-p line wrappers)) ;If this line is empty or
1320 (push line lines) ;invalid, just use it.
1321 (return-from find-free))
1322 (when (and wrappedp (>= line primary))
1323 ;; have gone all the way around the cache, time to quit
1324 (return-from find-free-cache-line (values primary nil)))
1325 (let ((osep (line-separation (line-primary line) line)))
1326 (when (>= osep limit)
1327 (return-from find-free-cache-line (values primary nil)))
1328 (when (cond ((= nsep limit) t)
1329 ((= nsep osep) (zerop (random 2)))
1332 ;; See whether we can displace what is in this line so that we
1333 ;; can use the line.
1334 (when (= line (the fixnum (1- (nlines)))) (setq wrappedp t))
1335 (setq p (line-primary line))
1336 (setq s (next-line line))
1339 (when (= line (the fixnum (1- (nlines)))) (setq wrappedp t)))))
1340 ;; Do all the displacing.
1342 (when (null (cdr lines)) (return nil))
1343 (let ((dline (pop lines))
1345 (declare (fixnum dline line))
1346 ;;Copy from line to dline (dline is known to be free).
1347 (let ((from-loc (line-location line))
1348 (to-loc (line-location dline))
1349 (cache-vector (vector)))
1350 (declare (fixnum from-loc to-loc) (simple-vector cache-vector))
1351 (modify-cache cache-vector
1352 (dotimes-fixnum (i (line-size))
1353 (setf (cache-vector-ref cache-vector
1355 (cache-vector-ref cache-vector
1357 (setf (cache-vector-ref cache-vector
1360 (values (car lines) t))))
1362 (defun default-limit-fn (nlines)
1368 (defvar *empty-cache* (make-cache)) ; for defstruct slot initial value forms
1370 ;;; Pre-allocate generic function caches. The hope is that this will
1371 ;;; put them nicely together in memory, and that that may be a win. Of
1372 ;;; course the first GC copy will probably blow that out, this really
1373 ;;; wants to be wrapped in something that declares the area static.
1375 ;;; This preallocation only creates about 25% more caches than PCL
1376 ;;; itself uses. Some ports may want to preallocate some more of
1379 ;;; KLUDGE: Isn't something very similar going on in precom1.lisp? Do
1380 ;;; we need it both here and there? Why? -- WHN 19991203
1381 (eval-when (:load-toplevel)
1382 (dolist (n-size '((1 513)(3 257)(3 129)(14 128)(6 65)(2 64)(7 33)(16 32)
1383 (16 17)(32 16)(64 9)(64 8)(6 5)(128 4)(35 2)))
1384 (let ((n (car n-size))
1385 (size (cadr n-size)))
1386 (mapcar #'free-cache-vector
1387 (mapcar #'get-cache-vector
1388 (make-list n :initial-element size))))))
1390 (defun caches-to-allocate ()
1391 (sort (let ((l nil))
1392 (maphash #'(lambda (size entry)
1393 (push (list (car entry) size) l))
1394 sb-pcl::*free-caches*)