;;;; heap-grovelling memory usage stuff

;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;;
;;;; This software is derived from the CMU CL system, which was
;;;; written at Carnegie Mellon University and released into the
;;;; public domain. The software is in the public domain and is
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.

(in-package "SB-VM")

(eval-when (:compile-toplevel :load-toplevel :execute)
  (export 'sb-sys::get-page-size "SB-SYS"))

;;;; type format database

(defstruct (room-info (:constructor make-room-info (mask name kind))
                      (:copier nil))
    ;; the mask applied to HeaderValue to compute object size
    (mask 0 :type (and fixnum unsigned-byte))
    ;; the name of this type
    (name nil :type symbol :read-only t)
    ;; kind of type (how to reconstitute an object)
    (kind nil
          :type (member :other :closure :instance :list :code :vector-nil)
          :read-only t))

(defun room-info-type-name (info)
    (if (specialized-array-element-type-properties-p info)
        (saetp-primitive-type-name info)
        (room-info-name info)))

(defun !compute-room-infos ()
  (let ((infos (make-array 256 :initial-element nil))
        (default-size-mask (mask-field (byte 23 0) -1)))
    (dolist (obj *primitive-objects*)
      (let ((widetag (primitive-object-widetag obj))
            (lowtag (primitive-object-lowtag obj))
            (name (primitive-object-name obj)))
        (when (and (eq lowtag 'other-pointer-lowtag)
                   (not (member widetag '(t nil))))
          (setf (svref infos (symbol-value widetag))
                (make-room-info (if (member name '(fdefn symbol))
                                    #xFF
                                    default-size-mask)
                                name :other)))))

    (dolist (code (list #+sb-unicode complex-character-string-widetag
                        complex-base-string-widetag simple-array-widetag
                        complex-bit-vector-widetag complex-vector-widetag
                        complex-array-widetag complex-vector-nil-widetag))
      (setf (svref infos code)
            (make-room-info default-size-mask 'array-header :other)))

    (setf (svref infos bignum-widetag)
          ;; Lose 1 more bit than n-widetag-bits because fullcgc robs 1 bit,
          ;; not that this is expected to work concurrently with gc.
          (make-room-info (ash most-positive-word (- (1+ n-widetag-bits)))
                          'bignum :other))

    (setf (svref infos closure-widetag)
          (make-room-info short-header-max-words 'closure :closure))

    (dotimes (i (length *specialized-array-element-type-properties*))
      (let ((saetp (aref *specialized-array-element-type-properties* i)))
        (when (saetp-specifier saetp) ;; SIMPLE-ARRAY-NIL is a special case.
          (setf (svref infos (saetp-typecode saetp)) saetp))))

    (setf (svref infos simple-array-nil-widetag)
          (make-room-info 0 'simple-array-nil :vector-nil))

    (setf (svref infos code-header-widetag)
          (make-room-info 0 'code :code))

    (setf (svref infos instance-widetag)
          (make-room-info 0 'instance :instance))

    (setf (svref infos funcallable-instance-widetag)
          (make-room-info short-header-max-words 'funcallable-instance :closure))

    (let ((cons-info (make-room-info 0 'cons :list)))
      ;; A cons consists of two words, both of which may be either a
      ;; pointer or immediate data.  According to the runtime this means
      ;; either a fixnum, a character, an unbound-marker, a single-float
      ;; on a 64-bit system, or a pointer.
      (dotimes (i (ash 1 (- n-widetag-bits n-fixnum-tag-bits)))
        (setf (svref infos (ash i n-fixnum-tag-bits)) cons-info))

      (dotimes (i (ash 1 (- n-widetag-bits n-lowtag-bits)))
        (setf (svref infos (logior (ash i n-lowtag-bits) instance-pointer-lowtag))
              cons-info)
        (setf (svref infos (logior (ash i n-lowtag-bits) list-pointer-lowtag))
              cons-info)
        (setf (svref infos (logior (ash i n-lowtag-bits) fun-pointer-lowtag))
              cons-info)
        (setf (svref infos (logior (ash i n-lowtag-bits) other-pointer-lowtag))
              cons-info))

      (setf (svref infos character-widetag) cons-info)

      (setf (svref infos unbound-marker-widetag) cons-info)

      ;; Single-floats are immediate data on 64-bit systems.
      #+64-bit (setf (svref infos single-float-widetag) cons-info))

    infos))

(define-load-time-global *room-info* (!compute-room-infos))

(defconstant-eqx +heap-spaces+
  '((:dynamic   "Dynamic space"   sb-kernel:dynamic-usage)
    #+immobile-space
    (:immobile  "Immobile space"  sb-kernel::immobile-space-usage)
    (:read-only "Read-only space" sb-kernel::read-only-space-usage)
    (:static    "Static space"    sb-kernel::static-space-usage))
  #'equal)

(defconstant-eqx +stack-spaces+
  '((:control-stack "Control stack" sb-kernel::control-stack-usage)
    (:binding-stack "Binding stack" sb-kernel::binding-stack-usage))
  #'equal)

(defconstant-eqx +all-spaces+ (append +heap-spaces+ +stack-spaces+) #'equal)

(defconstant-eqx +heap-space-keywords+ (mapcar #'first +heap-spaces+) #'equal)
(deftype spaces () `(member . ,+heap-space-keywords+))


;;;; MAP-ALLOCATED-OBJECTS

;;; Return the lower limit and current free-pointer of SPACE as fixnums
;;; whose raw bits (at the register level) represent a pointer.
;;; This makes it "off" by a factor of (EXPT 2 N-FIXNUM-TAG-BITS) - and/or
;;; possibly negative - if you look at the value in Lisp,
;;; but avoids potentially needing a bignum on 32-bit machines.
;;; 64-bit machines have no problem since most current generation CPUs
;;; use an address width that is narrower than 64 bits.
;;; This function is private because of the wacky representation.
(defun %space-bounds (space)
  (macrolet ((bounds (a b) `(values (%make-lisp-obj ,a) (%make-lisp-obj ,b))))
    (ecase space
      (:static
       (bounds static-space-start
               (sap-int *static-space-free-pointer*)))
      (:read-only
       (bounds read-only-space-start
               (sap-int *read-only-space-free-pointer*)))
      #+immobile-space
      (:fixed
       (bounds fixedobj-space-start
               (sap-int *fixedobj-space-free-pointer*)))
      #+immobile-space
      (:variable
       (bounds varyobj-space-start
               (sap-int *varyobj-space-free-pointer*)))
      (:dynamic
       (bounds (current-dynamic-space-start)
               (sap-int (dynamic-space-free-pointer)))))))

;;; Return the total number of bytes used in SPACE.
(defun space-bytes (space)
  (if (eq space :immobile)
      (+ (space-bytes :immobile-fixed)
         (space-bytes :immobile-variable))
      (multiple-value-bind (start end) (%space-bounds space)
        (ash (- end start) n-fixnum-tag-bits))))

;;; Round SIZE (in bytes) up to the next dualword boundary. A dualword
;;; is eight bytes on platforms with 32-bit word size and 16 bytes on
;;; platforms with 64-bit word size.
#-sb-fluid (declaim (inline round-to-dualword))
(defun round-to-dualword (size)
  (logand (the word (+ size lowtag-mask)) (lognot lowtag-mask)))

;;; Return the vector OBJ, its WIDETAG, and the number of octets
;;; required for its storage (including padding and alignment).
(defun reconstitute-vector (obj saetp)
  (declare (type (simple-array * (*)) obj)
           (type specialized-array-element-type-properties saetp))
  (let* ((length (+ (length obj)
                    (saetp-n-pad-elements saetp)))
         (n-bits (saetp-n-bits saetp))
         (alignment-pad (floor 7 n-bits))
         (n-data-octets (if (>= n-bits 8)
                            (* length (ash n-bits -3))
                            (ash (* (+ length alignment-pad)
                                    n-bits)
                                 -3))))
    (values obj
            (saetp-typecode saetp)
            (round-to-dualword (+ (* vector-data-offset n-word-bytes)
                                  n-data-octets)))))

(defun code-component-size (x) ; in bytes
  (declare (code-component x))
  (round-to-dualword
   (+ (* (logand (get-header-data x) short-header-max-words) n-word-bytes)
      (%code-code-size x))))

(defun primitive-object-size (object)
  "Return number of bytes of heap or stack directly consumed by OBJECT"
  (if (is-lisp-pointer (get-lisp-obj-address object))
      (let ((words
              (typecase object
                (cons 2)
                (instance (1+ (%instance-length object)))
                (function
                 (when (= (fun-subtype object) simple-fun-widetag)
                   (return-from primitive-object-size
                     (primitive-object-size (fun-code-header object))))
                 (1+ (get-closure-length object)))
                ;; NIL is larger than a symbol. I don't care to think about
                ;; why these fudge factors are right, but they make the result
                ;; equal to what MAP-ALLOCATED-OBJECTS reports.
                (null (+ symbol-size 1 #+64-bit 1))
                ;; Anything else is an OTHER pointer.
                ;; Use a sizing function when we have one,
                ;; otherwise the general case is correct.
                (t
                 (let ((room-info
                         (aref *room-info* (%other-pointer-widetag object))))
                   (typecase object
                     (array
                      (cond ((array-header-p object)
                             (+ array-dimensions-offset (array-rank object)))
                            ((simple-array-nil-p object) 2)
                            (t
                             (return-from primitive-object-size
                               (nth-value 2 (reconstitute-vector
                                             object room-info))))))
                     (code-component
                      (return-from primitive-object-size (code-component-size object)))
                     (t
                      ;; Other things (symbol, fdefn, value-cell, etc)
                      ;; don't have a sizer, so use GET-HEADER-DATA
                      (1+ (logand (get-header-data object)
                                  (logand (get-header-data object)
                                          (room-info-mask room-info)))))))))))
        (* (logandc2 (1+ words) 1)      ; round-to-even
           n-word-bytes))
      0))

;;; Given the address (untagged, aligned, and interpreted as a FIXNUM)
;;; of a lisp object, return the object, its "type code" (either
;;; LIST-POINTER-LOWTAG or a header widetag), and the number of octets
;;; required for its storage (including padding and alignment).  Note
;;; that this function is designed to NOT CONS, even if called
;;; out-of-line.
;;; FIXME: size calculation should be via PRIMITIVE-OBJECT-SIZE, not reinvented
(defun reconstitute-object (address)
  (let* ((object-sap (int-sap (get-lisp-obj-address address)))
         (header (sap-ref-word object-sap 0))
         (widetag (logand header widetag-mask))
         (header-value (ash header (- n-widetag-bits)))
         (info (svref *room-info* widetag)))
    (macrolet
        ((boxed-size (header-value)
           `(round-to-dualword (ash (1+ ,header-value) word-shift)))
         (tagged-object (tag)
           `(%make-lisp-obj (logior ,tag (get-lisp-obj-address address)))))
      (cond
          ;; Pick off arrays, as they're the only plausible cause for
          ;; a non-nil, non-ROOM-INFO object as INFO.
        ((specialized-array-element-type-properties-p info)
         (reconstitute-vector (tagged-object other-pointer-lowtag) info))
        ((= widetag sb-vm:filler-widetag)
         (values nil
                 sb-vm:filler-widetag
                 (boxed-size (logand header-value short-header-max-words))))
        ((null info)
         (error "Unrecognized widetag #x~2,'0X in reconstitute-object"
                widetag))

        (t
         (case (room-info-kind info)
          (:list
           (values (tagged-object list-pointer-lowtag)
                   list-pointer-lowtag
                   (* 2 n-word-bytes)))

          (:closure ; also funcallable-instance
           (values (tagged-object fun-pointer-lowtag)
                   widetag
                   (boxed-size (logand header-value short-header-max-words))))

          (:instance
           (values (tagged-object instance-pointer-lowtag)
                   widetag
                   (boxed-size (logand header-value short-header-max-words))))

          (:other
           (values (tagged-object other-pointer-lowtag)
                   widetag
                   (boxed-size (logand header-value (room-info-mask info)))))

          (:vector-nil
           (values (tagged-object other-pointer-lowtag)
                   simple-array-nil-widetag
                   (* 2 n-word-bytes)))

          (:code
           (let ((c (tagged-object other-pointer-lowtag)))
             (values c
                     code-header-widetag
                     (code-component-size c))))))))))

;;; Iterate over all the objects in the contiguous block of memory
;;; with the low address at START and the high address just before
;;; END, calling FUN with the object, the object's type code, and the
;;; object's total size in bytes, including any header and padding.
;;; START and END are untagged, aligned memory addresses interpreted
;;; as FIXNUMs (unlike SAPs or tagged addresses, these will not cons).
(defun map-objects-in-range (fun start end &optional (strict-bound t))
  (declare (type function fun))
  (declare (dynamic-extent fun))
  (named-let iter ((start start))
  (cond
    ((< (get-lisp-obj-address start) (get-lisp-obj-address end))
     (multiple-value-bind (obj typecode size) (reconstitute-object start)
      ;; SIZE is almost surely a fixnum. Non-fixnum would mean at least
      ;; a 512MB object if 32-bit words, and is inconceivable if 64-bit.
       (aver (not (logtest (the word size) lowtag-mask)))
       (unless (= typecode sb-vm:filler-widetag)
         (funcall fun obj typecode size))
             ;; This special little dance is to add a number of octets
             ;; (and it had best be a number evenly divisible by our
             ;; allocation granularity) to an unboxed, aligned address
             ;; masquerading as a fixnum.  Without consing.
      (iter (%make-lisp-obj
              (mask-field (byte #.n-word-bits 0)
                          (+ (get-lisp-obj-address start)
                             size))))))
    (strict-bound
     ;; If START is not eq to END, then we have blown past our endpoint.
     (aver (eq start end))))))

;;; Access to the GENCGC page table for better precision in
;;; MAP-ALLOCATED-OBJECTS
#+gencgc
(progn
  (define-alien-type (struct page)
      (struct page
              ;; To cut down the size of the page table, the scan_start_offset
              ;; - a/k/a "start" - is measured in 4-byte integers regardless
              ;; of word size. This is fine for 32-bit address space,
              ;; but if 64-bit then we have to scale the value. Additionally
              ;; there is a fallback for when even the scaled value is too big.
              ;; (None of this matters to Lisp code for the most part)
              (start #+64-bit (unsigned 32) #-64-bit signed)
              ;; On platforms with small enough GC pages, this field
              ;; will be a short. On platforms with larger ones, it'll
              ;; be an int.
              ;; Measured in bytes; the low bit has to be masked off.
              (bytes-used (unsigned
                           #.(if (typep gencgc-card-bytes '(unsigned-byte 16))
                                 16
                                 32)))
              (flags (unsigned 8))
              (gen (signed 8))))
  #+immobile-space
  (progn
    (define-alien-type (struct immobile-page)
        ;; ... and yet another place for Lisp to become out-of-sync with C.
        (struct immobile-page
                (flags (unsigned 8))
                (obj-spacing (unsigned 8))
                (obj-size (unsigned 8))
                (generations (unsigned 8))
                (free-index (unsigned 32))
                (page-link (unsigned 16))
                (prior-free-index (unsigned 16))))
    (define-alien-variable "fixedobj_pages" (* (struct immobile-page))))
  (declaim (inline find-page-index))
  (define-alien-routine ("ext_find_page_index" find-page-index)
    long (index unsigned))
  (define-alien-variable "next_free_page" sb-kernel::page-index-t)
  (define-alien-variable "page_table" (* (struct page))))

#+immobile-space
(progn
(deftype immobile-subspaces () '(member :fixed :variable))
(declaim (ftype (sfunction (function &rest immobile-subspaces) null)
                map-immobile-objects))
(defun map-immobile-objects (function &rest subspaces) ; Perform no filtering
  (declare (dynamic-extent function))
  (do-rest-arg ((subspace) subspaces)
    (multiple-value-bind (start end) (%space-bounds subspace)
      (map-objects-in-range function start end)))))

#|
MAP-ALLOCATED-OBJECTS is fundamentally unsafe to use if the user-supplied
function allocates anything. Consider what can happens when NEXT-FREE-PAGE
points to a partially filled page, and one more object is created extending
an allocation region that began on the formerly "last" page:

   0x10027cfff0: 0x00000000000000d9     <-- this was Lisp's view of
   0x10027cfff8: 0x0000000000000006         the last page (page 1273)
   ---- page boundary ----
   0x10027d0000: 0x0000001000005ecf     <-- next_free_page moves here (page 1274)
   0x10027d0008: 0x00000000000000ba
   0x10027d0010: 0x0000000000000040
   0x10027d0018: 0x0000000000000000

Lisp did not think that the page starting at 0x10027d0000 was allocated,
so it believes the stopping point is page 1273.  When we read the bytes-used
on that page, we see a totally full page, but do not consider adjoining any
additional pages into the contiguous block.
However the object, a vector, that started on page 1273 ends on page 1274,
causing MAP-OBJECTS-IN-RANGE to assert that it overran 0x10027d0000.

We could try a few things to mitigate this:
* Try to "chase" the value of next-free-page.  This is literally impossible -
  it's a moving target, and it's extremely likely to exhaust memory doing so,
  especially if the supplied lambda is an interpreted function.
  (Each object scanned causes consing of more bytes, and we never
  "catch up" to the moving next-free-page)

* If the page that we're looking at is full but the FINALLY clause is hit,
  don't stop looking for more pages in that one case. Instead keep looking
  for the end of the contiguous block, but stop as soon any potential
  stopping point is found; don't chase next-free-page.  This is tricky
  as well and just about as infeasible.

* Pass a flag to MAP-OBJECTS-IN-RANGE specifying that it's OK to
  surpass the expected bound - silently accept our fate.
  This is what we do since it's simple, and seems to work.
|#

;;; Iterate over all the objects allocated in each of the SPACES, calling FUN
;;; with the object, the object's type code, and the object's total size in
;;; bytes, including any header and padding. As a special case, if exactly one
;;; space named :ALL is requested, then map over the known spaces.
(defun map-allocated-objects (fun &rest spaces)
  (declare (type function fun)
           ;; KLUDGE: rest-arg and self calls do not play nice and it'll get consed
           (optimize (sb-c::recognize-self-calls 0)))
  (declare (dynamic-extent fun))
  (when (and (= (length spaces) 1) (eq (first spaces) :all))
    (return-from map-allocated-objects
     (map-allocated-objects fun
                            :read-only :static
                            #+immobile-space :immobile
                            :dynamic)))
  ;; You can't specify :ALL and also a list of spaces. Check that up front.
  (do-rest-arg ((space) spaces) (the spaces space))
  (flet ((do-1-space (space)
    (ecase space
      (:static
       ;; Static space starts with NIL, which requires special
       ;; handling, as the header and alignment are slightly off.
       (multiple-value-bind (start end) (%space-bounds space)
         ;; This "8" is very magical. It happens to work for both
         ;; word sizes, even though symbols differ in length
         ;; (they can be either 6 or 7 words).
         (funcall fun nil symbol-widetag (* 8 n-word-bytes))
         (map-objects-in-range fun
                               (+ (ash (* 8 n-word-bytes) (- n-fixnum-tag-bits))
                                  start)
                               end)))

      ((:read-only #-gencgc :dynamic)
       ;; Read-only space (and dynamic space on cheneygc) is a block
       ;; of contiguous allocations.
       (multiple-value-bind (start end) (%space-bounds space)
         (map-objects-in-range fun start end)))
      #+immobile-space
      (:immobile
       ;; Filter out filler objects. These either look like cons cells
       ;; in fixedobj subspace, or code without enough header words
       ;; in varyobj subspace. (cf 'filler_obj_p' in gc-internal.h)
       (dx-flet ((filter (obj type size)
                   (unless (consp obj)
                     (funcall fun obj type size))))
         (map-immobile-objects #'filter :fixed))
       (dx-flet ((filter (obj type size)
                   (unless (and (code-component-p obj)
                                (eql (code-header-words obj) 2))
                     (funcall fun obj type size))))
         (map-immobile-objects #'filter :variable)))

      #+gencgc
      (:dynamic
       ;; Dynamic space on gencgc requires walking the GC page tables
       ;; in order to determine what regions contain objects.

       ;; We explicitly presume that any pages in an allocation region
       ;; that are in-use have a BYTES-USED of GENCGC-CARD-BYTES
       ;; (indicating a full page) or an otherwise-valid BYTES-USED.
       ;; We also presume that the pages of an open allocation region
       ;; after the first page, and any pages that are unallocated,
       ;; have a BYTES-USED of zero.  GENCGC seems to guarantee this.

       ;; Our procedure is to scan forward through the page table,
       ;; maintaining an "end pointer" until we reach a page where
       ;; BYTES-USED is not GENCGC-CARD-BYTES or we reach
       ;; NEXT-FREE-PAGE.  We then MAP-OBJECTS-IN-RANGE if the range
       ;; is not empty, and proceed to the next page (unless we've hit
       ;; NEXT-FREE-PAGE).  We happily take advantage of the fact that
       ;; MAP-OBJECTS-IN-RANGE will simply return if passed two
       ;; coincident pointers for the range.

       ;; FIXME: WITHOUT-GCING prevents a GC flip, but doesn't prevent
       ;; closing allocation regions and opening new ones.  This may
       ;; prove to be an issue with concurrent systems, or with
       ;; spectacularly poor timing for closing an allocation region
       ;; in a single-threaded system.
       #+sb-thread
       (close-current-gc-region)
       (loop
          with page-size = (ash gencgc-card-bytes (- n-fixnum-tag-bits))
          ;; This magic dance gets us an unboxed aligned pointer as a
          ;; FIXNUM.
          with start = (%make-lisp-obj (current-dynamic-space-start))
          with end = start

          ;; This is our page range. The type constraint is far too generous,
          ;; but it does its job of producing efficient code.
          for page-index
          of-type (integer -1 (#.(/ (ash 1 n-machine-word-bits) gencgc-card-bytes)))
          from 0 below next-free-page
          for next-page-addr from (+ start page-size) by page-size
          for page-bytes-used
              ;; The low bits of bytes-used is the need-to-zero flag.
              = (logandc1 1 (slot (deref page-table page-index) 'bytes-used))

          when (< page-bytes-used gencgc-card-bytes)
          do (progn
               (incf end (ash page-bytes-used (- n-fixnum-tag-bits)))
               (map-objects-in-range fun start end)
               (setf start next-page-addr)
               (setf end next-page-addr))
          else do (incf end page-size)

          finally (map-objects-in-range fun start end nil))))))
  (do-rest-arg ((space) spaces)
    (if (eq space :dynamic)
        (without-gcing (do-1-space space))
        (do-1-space space)))))

#+(and sb-thread gencgc)
;; Start with a Lisp rendition of ensure_region_closed() on the active
;; thread's region, since users are often surprised to learn that a
;; just-consed object can't necessarily be seen by MAP-ALLOCATED-OBJECTS.
;; Since we're in WITHOUT-GCING, there can be no interrupts.
;; This is probably better than calling MAP-OBJECTS-IN-RANGE on the
;; thread's region, because then we might visit some page twice
;; by doing that.
;; (And seeing small consing by other threads is hopeless either way)
(defun close-current-gc-region ()
  (unless (eql (sap-int (current-thread-offset-sap
                         (+ thread-alloc-region-slot 3)))
               0)                       ; start_addr
    (alien-funcall
     (extern-alien "gc_close_region" (function void unsigned int))
     (truly-the word
                (+ (sb-thread::thread-primitive-thread sb-thread:*current-thread*)
                   (ash thread-alloc-region-slot word-shift)))
     1)))

;;;; MEMORY-USAGE

#+immobile-space
(progn
(declaim (ftype (function (immobile-subspaces) (values t t t &optional))
                immobile-fragmentation-information))
(defun immobile-fragmentation-information (subspace)
  (binding* (((start free-pointer) (%space-bounds subspace))
             (used-bytes (ash (- free-pointer start) n-fixnum-tag-bits))
             (holes '())
             (hole-bytes 0))
    (map-immobile-objects
     (lambda (obj type size)
       (declare (ignore type))
       (let ((address (logandc2 (get-lisp-obj-address obj) lowtag-mask)))
         (when (case subspace
                 (:fixed (consp obj))
                 (:variable (hole-p address)))
           (push (cons address size) holes)
           (incf hole-bytes size))))
     subspace)
    (values holes hole-bytes used-bytes)))

(defun show-fragmentation (&key (subspaces '(:fixed :variable))
                                (stream *standard-output*))
  (dolist (subspace subspaces)
    (format stream "~(~A~) subspace fragmentation:~%" subspace)
    (multiple-value-bind (holes hole-bytes total-space-used)
        (immobile-fragmentation-information subspace)
      (loop for (start . size) in holes
            do (format stream "~2@T~X..~X ~8:D~%" start (+ start size) size))
      (format stream "~2@T~18@<~:D hole~:P~> ~8:D (~,2,2F% of ~:D ~
                      bytes used)~%"
              (length holes) hole-bytes
              (/ hole-bytes total-space-used) total-space-used))))

(defun sb-kernel::immobile-space-usage ()
  (binding* (((nil fixed-hole-bytes fixed-used-bytes)
              (immobile-fragmentation-information :fixed))
             ((nil variable-hole-bytes variable-used-bytes)
              (immobile-fragmentation-information :variable))
             (total-used-bytes (+ fixed-used-bytes variable-used-bytes))
             (total-hole-bytes (+ fixed-hole-bytes variable-hole-bytes)))
    (values total-used-bytes total-hole-bytes)))
) ; end PROGN

;;; Return a list of 3-lists (bytes object type-name) for the objects
;;; allocated in Space.
(defun type-breakdown (space)
  (declare (muffle-conditions t))
  (let ((sizes (make-array 256 :initial-element 0 :element-type '(unsigned-byte #.n-word-bits)))
        (counts (make-array 256 :initial-element 0 :element-type '(unsigned-byte #.n-word-bits))))
    (map-allocated-objects
     (lambda (obj type size)
       (declare (word size) (optimize (speed 3)) (ignore obj))
       (incf (aref sizes type) size)
       (incf (aref counts type)))
     space)

    (let ((totals (make-hash-table :test 'eq)))
      (dotimes (i 256)
        (let ((total-count (aref counts i)))
          (unless (zerop total-count)
            (let* ((total-size (aref sizes i))
                   (name (room-info-type-name (aref *room-info* i)))
                   (found (ensure-gethash name totals (list 0 0 name))))
              (incf (first found) total-size)
              (incf (second found) total-count)))))

      (collect ((totals-list))
        (maphash (lambda (k v)
                   (declare (ignore k))
                   (totals-list v))
                 totals)
        (sort (totals-list) #'> :key #'first)))))

;;; Handle the summary printing for MEMORY-USAGE. Totals is a list of lists
;;; (space-name . totals-for-space), where totals-for-space is the list
;;; returned by TYPE-BREAKDOWN.
(defun print-summary (spaces totals)
  (let ((summary (make-hash-table :test 'eq))
        (space-count (length spaces)))
    (dolist (space-total totals)
      (dolist (total (cdr space-total))
        (push (cons (car space-total) total)
              (gethash (third total) summary))))

    (collect ((summary-totals))
      (maphash (lambda (k v)
                 (declare (ignore k))
                 (let ((sum 0))
                   (declare (unsigned-byte sum))
                   (dolist (space-total v)
                     (incf sum (first (cdr space-total))))
                   (summary-totals (cons sum v))))
               summary)

      (format t "~2&Summary of space~P: ~(~{~A ~}~)~%" space-count spaces)
      (let ((summary-total-bytes 0)
            (summary-total-objects 0))
        (declare (unsigned-byte summary-total-bytes summary-total-objects))
        (dolist (space-totals
                 (mapcar #'cdr (sort (summary-totals) #'> :key #'car)))
          (let ((total-objects 0)
                (total-bytes 0)
                name)
            (declare (unsigned-byte total-objects total-bytes))
            (collect ((spaces))
              (dolist (space-total space-totals)
                (let ((total (cdr space-total)))
                  (setq name (third total))
                  (incf total-bytes (first total))
                  (incf total-objects (second total))
                  (spaces (cons (car space-total) (first total)))))
              (format t "~%~A:~%    ~:D bytes, ~:D object~:P"
                      name total-bytes total-objects)
              (unless (= 1 space-count)
                (dolist (space (spaces))
                  (format t ", ~D% ~(~A~)"
                          (round (* (cdr space) 100) total-bytes) (car space))))
              (format t ".~%")
              (incf summary-total-bytes total-bytes)
              (incf summary-total-objects total-objects))))
        (format t "~%Summary total:~%    ~:D bytes, ~:D objects.~%"
                summary-total-bytes summary-total-objects)))))

;;; Report object usage for a single space.
(defun report-space-total (space-info cutoff)
  (declare (list space-info) (type (or single-float null) cutoff))
  (destructuring-bind (space . types) space-info
    (format t "~2&Breakdown for ~(~A~) space:~%" space)
    (let* ((total-bytes (reduce #'+ (mapcar #'first types)))
           (bytes-width (decimal-with-grouped-digits-width total-bytes))
           (total-objects (reduce #'+ (mapcar #'second types)))
           (objects-width (decimal-with-grouped-digits-width total-objects))
           (cutoff-point (if cutoff
                             (truncate (* (float total-bytes) cutoff))
                             0))
           (reported-bytes 0)
           (reported-objects 0))
      (declare (unsigned-byte total-objects total-bytes cutoff-point
                              reported-objects reported-bytes))
      (flet ((type-usage (bytes objects name &optional note)
               (format t "  ~V:D bytes for ~V:D ~(~A~) object~2:*~P~*~
                          ~:[~; ~:*(~A)~]~%"
                       bytes-width bytes objects-width objects name note)))
        (loop for (bytes objects name) in types do
             (when (<= bytes cutoff-point)
               (type-usage (- total-bytes reported-bytes)
                           (- total-objects reported-objects)
                           "other")
               (return))
             (incf reported-bytes bytes)
             (incf reported-objects objects)
             (type-usage bytes objects name))
        (terpri)
        (type-usage total-bytes total-objects space "space total")))))

;;; Print information about the heap memory in use. PRINT-SPACES is a
;;; list of the spaces to print detailed information for.
;;; COUNT-SPACES is a list of the spaces to scan. For either one, T
;;; means all spaces (i.e. :STATIC, :DYNAMIC and :READ-ONLY.) If
;;; PRINT-SUMMARY is true, then summary information will be printed.
;;; The defaults print only summary information for dynamic space. If
;;; true, CUTOFF is a fraction of the usage in a report below which
;;; types will be combined as OTHER.
(defun memory-usage (&key print-spaces (count-spaces '(:dynamic #+immobile-space :immobile))
                          (print-summary t) cutoff)
  (declare (type (or single-float null) cutoff))
  (let* ((spaces (if (eq count-spaces t) +heap-space-keywords+ count-spaces))
         (totals (mapcar (lambda (space)
                           (cons space (type-breakdown space)))
                         spaces)))

    (dolist (space-total totals)
      (when (or (eq print-spaces t)
                (member (car space-total) print-spaces))
        (report-space-total space-total cutoff)))

    (when print-summary (print-summary spaces totals)))

  (values))

;;; Print a breakdown by instance type of all the instances allocated
;;; in SPACE. If TOP-N is true, print only information for the
;;; TOP-N types with largest usage.
(defun instance-usage (space &key (top-n 15))
  (declare (type spaces space) (type (or fixnum null) top-n))
  (format t "~2&~@[Top ~W ~]~(~A~) instance types:~%" top-n space)
  (let ((totals (make-hash-table :test 'eq))
        (total-objects 0)
        (total-bytes 0))
    (declare (unsigned-byte total-objects total-bytes))
    (map-allocated-objects
     (lambda (obj type size)
       (declare (optimize (speed 3)))
       (when (eql type instance-widetag)
         (incf total-objects)
         (let* ((classoid (layout-classoid (%instance-layout obj)))
                (found (ensure-gethash classoid totals (cons 0 0)))
                (size size))
           (declare (fixnum size))
           (incf total-bytes size)
           (incf (the fixnum (car found)))
           (incf (the fixnum (cdr found)) size))))
     space)
    (let* ((sorted (sort (%hash-table-alist totals) #'> :key #'cddr))
           (interesting (if top-n
                            (subseq sorted 0 (min (length sorted) top-n))
                            sorted))
           (bytes-width (decimal-with-grouped-digits-width total-bytes))
           (objects-width (decimal-with-grouped-digits-width total-objects))
           (totals-label (format nil "~:(~A~) instance total" space))
           (types-width (reduce #'max interesting
                                :key (lambda (x)
                                       (length (symbol-name (classoid-name (first x)))))
                                :initial-value (length totals-label)))
           (printed-bytes 0)
           (printed-objects 0))
      (declare (unsigned-byte printed-bytes printed-objects))
      (flet ((type-usage (type objects bytes)
               (let ((name (etypecase type
                             (string type)
                             (classoid (symbol-name (classoid-name type))))))
                 (format t "  ~V@<~A~> ~V:D bytes, ~V:D object~:P.~%"
                         (1+ types-width) name bytes-width bytes
                         objects-width objects))))
        (loop for (type . (objects . bytes)) in interesting do
             (incf printed-bytes bytes)
             (incf printed-objects objects)
             (type-usage type objects bytes))
        (terpri)
        (let ((residual-objects (- total-objects printed-objects))
              (residual-bytes (- total-bytes printed-bytes)))
          (unless (zerop residual-objects)
            (type-usage "Other types" residual-objects residual-bytes)))
        (type-usage totals-label total-objects total-bytes))))
  (values))

;;;; PRINT-ALLOCATED-OBJECTS

;;; This notion of page-size is completely arbitrary - it affects 2 things:
;;; (1) how much output to print "per page" in print-allocated-objects
;;; (2) sb-sprof deciding how many regions [sic] were made if #+cheneygc
(defun get-page-size () sb-c:+backend-page-bytes+)

(defun print-allocated-objects (space &key (percent 0) (pages 5)
                                      type larger smaller count
                                      (stream *standard-output*))
  (declare (type (integer 0 99) percent) (type index pages)
           (type stream stream) (type spaces space)
           (type (or index null) type larger smaller count))
  (multiple-value-bind (start end) (%space-bounds space)
    (let* ((space-start (ash start n-fixnum-tag-bits))
           (space-end (ash end n-fixnum-tag-bits))
           (space-size (- space-end space-start))
           (pagesize (get-page-size))
           (start (+ space-start (round (* space-size percent) 100)))
           (printed-conses (make-hash-table :test 'eq))
           (pages-so-far 0)
           (count-so-far 0)
           (last-page 0))
      (declare (type word last-page start)
               (fixnum pages-so-far count-so-far pagesize))
      (labels ((note-conses (x)
                 (unless (or (atom x) (gethash x printed-conses))
                   (setf (gethash x printed-conses) t)
                   (note-conses (car x))
                   (note-conses (cdr x)))))
        (map-allocated-objects
         (lambda (obj obj-type size)
           (let ((addr (get-lisp-obj-address obj)))
             (when (>= addr start)
               (when (if count
                         (> count-so-far count)
                         (> pages-so-far pages))
                 (return-from print-allocated-objects (values)))

               (unless count
                 (let ((this-page (* (the (values word t)
                                       (truncate addr pagesize))
                                     pagesize)))
                   (declare (type word this-page))
                   (when (/= this-page last-page)
                     (when (< pages-so-far pages)
                       ;; FIXME: What is this? (ERROR "Argh..")? or
                       ;; a warning? or code that can be removed
                       ;; once the system is stable? or what?
                       (format stream "~2&**** Page ~W, address ~X:~%"
                               pages-so-far addr))
                     (setq last-page this-page)
                     (incf pages-so-far))))

               (when (and (or (not type) (eql obj-type type))
                          (or (not smaller) (<= size smaller))
                          (or (not larger) (>= size larger)))
                 (incf count-so-far)
                 (case type
                   (#.code-header-widetag
                    (let ((dinfo (%code-debug-info obj)))
                      (format stream "~&Code object: ~S~%"
                              (if dinfo
                                  (sb-c::compiled-debug-info-name dinfo)
                                  "No debug info."))))
                   (#.symbol-widetag
                    (format stream "~&~S~%" obj))
                   (#.list-pointer-lowtag
                    (unless (gethash obj printed-conses)
                      (note-conses obj)
                      (let ((*print-circle* t)
                            (*print-level* 5)
                            (*print-length* 10))
                        (format stream "~&~S~%" obj))))
                   (t
                    (fresh-line stream)
                    (let ((str (write-to-string obj :level 5 :length 10
                                                :pretty nil)))
                      (unless (eql type instance-widetag)
                        (format stream "~S: " (type-of obj)))
                      (format stream "~A~%"
                              (subseq str 0 (min (length str) 60))))))))))
         space))))
  (values))

;;;; LIST-ALLOCATED-OBJECTS, LIST-REFERENCING-OBJECTS

(defvar *ignore-after* nil)

(defun valid-obj (space x)
  (or (not (eq space :dynamic))
      ;; this test looks bogus if the allocator doesn't work linearly,
      ;; which I suspect is the case for GENCGC.  -- CSR, 2004-06-29
      (< (get-lisp-obj-address x) (get-lisp-obj-address *ignore-after*))))

(defun maybe-cons (space x stuff)
  (if (valid-obj space x)
      (cons x stuff)
      stuff))

(defun list-allocated-objects (space &key type larger smaller count
                                     test)
  (declare (type spaces space)
           (type (or index null) larger smaller type count)
           (type (or function null) test))
  (declare (dynamic-extent test))
  (unless *ignore-after*
    (setq *ignore-after* (cons 1 2)))
  (collect ((counted 0 1+))
    (let ((res ()))
      (map-allocated-objects
       (lambda (obj obj-type size)
         (when (and (or (not type) (eql obj-type type))
                    (or (not smaller) (<= size smaller))
                    (or (not larger) (>= size larger))
                    (or (not test) (funcall test obj)))
           (setq res (maybe-cons space obj res))
           (when (and count (>= (counted) count))
             (return-from list-allocated-objects res))))
       space)
      res)))

;;; Calls FUNCTION with all objects that have (possibly conservative)
;;; references to them on current stack.
;;; This is for use by SB-INTROSPECT. (Other consumers, at your own risk)
;;; Note that we do not call MAKE-LISP-OBJ in the errorp=nil mode, as it
;;; potentially uses FORMAT and MAKE-UNPRINTABLE-OBJECT with each invocation.
;;; And see the cautionary remarks above that function regarding its dangerous
;;; nature (more so on precise GC).  On conservative GC we should be OK here
;;; because we know that there's a stack reference.
(defun map-stack-references (function)
  (declare (type function function))
  (declare (dynamic-extent function))
  (macrolet ((iter (step limit test)
               `(do ((sp (current-sp) (sap+ sp (,step n-word-bytes)))
                     (limit (sb-di::descriptor-sap ,limit))
                     (seen nil))
                    ((,test sp limit))
                  (let ((word (sap-ref-word sp 0)))
                    ;; Explicitly skip non-pointer words. The callable that
                    ;; SB-INTROSPECT provides ignores immediate values anyway.
                    (when (and (is-lisp-pointer word)
                               (not (zerop (sb-di::valid-lisp-pointer-p (int-sap word)))))
                      (let ((obj (%make-lisp-obj word)))
                        (unless (memq obj seen)
                          (push obj seen)
                          (funcall function obj))))))))
    #+stack-grows-downward-not-upward (iter + *control-stack-end* sap>)
    #-stack-grows-downward-not-upward (iter - *control-stack-start* sap<)))

;;; This interface allows one either to be agnostic of the referencing space,
;;; or specify exactly one space, but not specify a list of spaces.
;;; An upward-compatible change would be to assume a list, and call ENSURE-LIST.
(defun map-referencing-objects (fun space object)
  (declare (type (or (eql :all) spaces) space))
  (unless *ignore-after*
    (setq *ignore-after* (cons 1 2)))
  (flet ((ref-p (this widetag nwords) ; return T if 'this' references object
           (when (listp this)
             (return-from ref-p
               (or (eq (car this) object) (eq (cdr this) object))))
           (case widetag
             ;; purely boxed objects
             ((#.ratio-widetag #.complex-widetag #.value-cell-widetag
               #.symbol-widetag #.weak-pointer-widetag
               #.simple-array-widetag #.simple-vector-widetag
               #.complex-array-widetag #.complex-vector-widetag
               #.complex-bit-vector-widetag #.complex-vector-nil-widetag
               #.complex-base-string-widetag
               #+sb-unicode #.complex-character-string-widetag))
             ;; mixed boxed/unboxed objects
             (#.code-header-widetag
              (dotimes (i (code-n-entries this))
                (let ((f (%code-entry-point this i)))
                  (when (or (eq f object)
                            (eq (%simple-fun-name f) object)
                            (eq (%simple-fun-arglist f) object)
                            (eq (%simple-fun-type f) object)
                            (eq (%simple-fun-info f) object))
                    (return-from ref-p t))))
              (setq nwords (code-header-words this)))
             (#.instance-widetag
              (return-from ref-p
                (or (eq (%instance-layout this) object)
                    (do-instance-tagged-slot (i this)
                      (when (eq (%instance-ref this i) object)
                        (return t))))))
             (#.funcallable-instance-widetag
              (let ((l (%funcallable-instance-layout this)))
                (when (eq l object)
                  (return-from ref-p t))
                (let ((bitmap (layout-bitmap l)))
                  (unless (eql bitmap -1)
                    ;; tagged slots precede untagged slots,
                    ;; so integer-length is the count of tagged slots.
                    (setq nwords (1+ (integer-length bitmap)))))))
             (#.closure-widetag
              (when (eq (%closure-fun this) object)
                (return-from ref-p t)))
             (#.fdefn-widetag
              #+immobile-code
              (when (eq (make-lisp-obj
                         (alien-funcall
                          (extern-alien "fdefn_callee_lispobj" (function unsigned unsigned))
                          (logandc2 (get-lisp-obj-address this) lowtag-mask)))
                        object)
                (return-from ref-p t))
              ;; Without immobile-code the 'raw-addr' slot either holds the same thing
              ;; as the 'fun' slot, or holds a trampoline address. We'll overlook the
              ;; minor issue that due to concurrent writes, two representations of the
              ;; allegedly same referent may diverge; thus the last slot is skipped
              ;; even if it refers to a different simple-fun.
              (decf nwords))
             (t
              (return-from ref-p nil)))
           ;; gencgc has WITHOUT-GCING in map-allocated-objects over dynamic space,
           ;; so we don't have to pin each object inside REF-P.
           (#+cheneygc with-pinned-objects #+cheneygc (this)
            #-cheneygc progn
            (do ((sap (int-sap (logandc2 (get-lisp-obj-address this) lowtag-mask)))
                 (i (* (1- nwords) n-word-bytes) (- i n-word-bytes)))
                ((<= i 0) nil)
              (when (eq (sap-ref-lispobj sap i) object)
                (return t))))))
    (let ((fun (%coerce-callable-to-fun fun)))
      (dx-flet ((mapfun (obj widetag size)
                  (when (and (ref-p obj widetag (/ size n-word-bytes))
                             (valid-obj space obj))
                    (funcall fun obj))))
        (map-allocated-objects #'mapfun space)))))

(defun list-referencing-objects (space object)
  (collect ((res))
    (map-referencing-objects
     (lambda (obj) (res obj)) space object)
    (res)))

;;;; ROOM

(defun room-minimal-info ()
  (multiple-value-bind (names name-width
                        used-bytes used-bytes-width
                        overhead-bytes)
      (loop for (nil name function) in +all-spaces+
            for (space-used-bytes space-overhead-bytes)
               = (multiple-value-list (funcall function))
            collect name into names
            collect space-used-bytes into used-bytes
            collect space-overhead-bytes into overhead-bytes
            maximizing (length name) into name-maximum
            maximizing space-used-bytes into used-bytes-maximum
            finally (return (values
                             names name-maximum
                             used-bytes (decimal-with-grouped-digits-width
                                         used-bytes-maximum)
                             overhead-bytes)))
    (loop for name in names
          for space-used-bytes in used-bytes
          for space-overhead-bytes in overhead-bytes
          do (format t "~V@<~A usage is:~> ~V:D bytes~@[ (~:D bytes ~
                        overhead)~].~%"
                     (+ name-width 10) name used-bytes-width space-used-bytes
                     space-overhead-bytes)))
  #+sb-thread
  (format t "Control and binding stack usage is for the current thread ~
             only.~%")
  (format t "Garbage collection is currently ~:[enabled~;DISABLED~].~%"
          *gc-inhibit*))

(defun room-intermediate-info ()
  (room-minimal-info)
  (memory-usage :count-spaces '(:dynamic #+immobile-space :immobile)
                :print-spaces t
                :cutoff 0.05f0
                :print-summary nil))

(defun room-maximal-info ()
  (let ((spaces '(:dynamic #+immobile-space :immobile :static)))
    (room-minimal-info)
    (memory-usage :count-spaces spaces)
    (dolist (space spaces)
      (instance-usage space :top-n 10))))

(defun room (&optional (verbosity :default))
  "Print to *STANDARD-OUTPUT* information about the state of internal
  storage and its management. The optional argument controls the
  verbosity of output. If it is T, ROOM prints out a maximal amount of
  information. If it is NIL, ROOM prints out a minimal amount of
  information. If it is :DEFAULT or it is not supplied, ROOM prints out
  an intermediate amount of information."
  (fresh-line)
  (ecase verbosity
    ((t)
     (room-maximal-info))
    ((nil)
     (room-minimal-info))
    (:default
     (room-intermediate-info)))
  (values))

#+nil ; for debugging
(defun dump-dynamic-space-code (&optional (stream *standard-output*)
                                &aux (n-code-bytes 0)
                                     (total-pages next-free-page)
                                     (pages
                                      (make-array total-pages :element-type 'bit)))
  (flet ((dump-page (page-num)
           (format stream "~&Page ~D~%" page-num)
           (let ((where (+ dynamic-space-start (* page-num gencgc-card-bytes)))
                 (seen-filler nil))
             (loop
               (multiple-value-bind (obj type size)
                   (reconstitute-object (ash where (- n-fixnum-tag-bits)))
                 (when (= type code-header-widetag)
                   (incf n-code-bytes size))
                 (when (if (and (consp obj) (eq (car obj) 0) (eq (cdr obj) 0))
                           (if seen-filler
                               (progn (write-char #\. stream) nil)
                               (setq seen-filler t))
                           (progn (setq seen-filler nil) t))
                   (let ((*print-pretty* nil))
                     (format stream "~&  ~X ~4X ~S " where size obj)))
                 (incf where size)
                 (loop for index from page-num to (find-page-index (1- where))
                       do (setf (sbit pages index) 1)))
               (let ((next-page (find-page-index where)))
                 (cond ((= (logand where (1- gencgc-card-bytes)) 0)
                        (format stream "~&-- END OF PAGE --~%")
                        (return next-page))
                       ((eq next-page page-num))
                       (t
                        (setq page-num next-page seen-filler nil))))))))
    (let ((i 0))
      (loop while (< i total-pages)
            do (let ((type (ldb (byte 2 0) (slot (deref page-table i) 'flags))))
                 (if (= type 3)
                     (setq i (dump-page i))
                     (incf i)))))
    (let* ((n-pages (count 1 pages))
           (tot (* n-pages gencgc-card-bytes))
           (waste (- tot n-code-bytes)))
      (format t "~&Used-bytes=~D Pages=~D Waste=~D (~F%)~%"
              n-code-bytes n-pages waste
              (* 100 (/ waste tot))))))

#+gencgc
(defun generation-of (object)
  (let* ((addr (get-lisp-obj-address object))
         (page (find-page-index addr)))
    (cond ((>= page 0) (slot (deref page-table page) 'gen))
          #+immobile-space
          ((immobile-space-addr-p addr)
           ;; SIMPLE-FUNs don't contain a generation byte
           (when (simple-fun-p object)
             (setq addr (get-lisp-obj-address (fun-code-header object))))
           (logand #xF (sap-ref-8 (int-sap (logandc2 addr lowtag-mask)) 3))))))

(in-package "SB-C")
;;; As soon as practical in warm build it makes sense to add
;;; cold-allocation-point-fixups into the weak hash-table.
(defvar *!cold-allocation-point-fixups*)
(let ((hash-table (make-hash-table :test 'eq)))
  ;; Group by code component
  (loop for (code . offset) across *!cold-allocation-point-fixups*
        do (push offset (gethash code hash-table)))
  (dohash ((code list) hash-table)
    (setf (gethash code *allocation-point-fixups*)
          (convert-alloc-point-fixups code list))))
