\f
;;;; DYNAMIC-USAGE and friends
-(declaim (special sb!vm:*read-only-space-free-pointer*
- sb!vm:*static-space-free-pointer*))
-
-(eval-when (:compile-toplevel :execute)
- (sb!xc:defmacro def-c-var-frob (lisp-fun c-var-name)
- `(progn
- #!-sb-fluid (declaim (inline ,lisp-fun))
- (defun ,lisp-fun ()
- (sb!alien:extern-alien ,c-var-name (sb!alien:unsigned 32))))))
-
+#!-sb-fluid
+(declaim (inline current-dynamic-space-start))
+#!+gencgc
+(defun current-dynamic-space-start () sb!vm:dynamic-space-start)
#!-gencgc
-(progn
- ;; This is called once per PROFILEd function call, so it's worth a
- ;; little possible space cost to reduce its time cost.
- #!-sb-fluid
- (declaim (inline current-dynamic-space-start))
- (def-c-var-frob current-dynamic-space-start "current_dynamic_space"))
+(defun current-dynamic-space-start ()
+ (sb!alien:extern-alien "current_dynamic_space" sb!alien:unsigned-long))
#!-sb-fluid
-(declaim (inline dynamic-usage)) ; to reduce PROFILEd call overhead
+(declaim (inline dynamic-usage))
#!+gencgc
-(def-c-var-frob dynamic-usage "bytes_allocated")
+(defun dynamic-usage ()
+ (sb!alien:extern-alien "bytes_allocated" os-vm-size-t))
#!-gencgc
(defun dynamic-usage ()
(the (unsigned-byte 32)
(current-dynamic-space-start))))
(defun static-space-usage ()
- (- (* sb!vm:*static-space-free-pointer* sb!vm:n-word-bytes)
+ (- (ash sb!vm:*static-space-free-pointer* sb!vm:n-fixnum-tag-bits)
sb!vm:static-space-start))
(defun read-only-space-usage ()
- (- (* sb!vm::*read-only-space-free-pointer* sb!vm:n-word-bytes)
+ (- (ash sb!vm::*read-only-space-free-pointer* sb!vm:n-fixnum-tag-bits)
sb!vm:read-only-space-start))
(defun control-stack-usage ()
#!-stack-grows-downward-not-upward
(- (sb!sys:sap-int (sb!c::control-stack-pointer-sap))
- sb!vm:control-stack-start)
+ (sb!sys:sap-int (sb!di::descriptor-sap sb!vm:*control-stack-start*)))
#!+stack-grows-downward-not-upward
- (- sb!vm:control-stack-end
+ (- (sb!sys:sap-int (sb!di::descriptor-sap sb!vm:*control-stack-end*))
(sb!sys:sap-int (sb!c::control-stack-pointer-sap))))
(defun binding-stack-usage ()
(- (sb!sys:sap-int (sb!c::binding-stack-pointer-sap))
- sb!vm:binding-stack-start))
+ (sb!sys:sap-int (sb!di::descriptor-sap sb!vm:*binding-stack-start*))))
\f
;;;; ROOM
(format t "Static space usage is: ~10:D bytes.~%" (static-space-usage))
(format t "Control stack usage is: ~10:D bytes.~%" (control-stack-usage))
(format t "Binding stack usage is: ~10:D bytes.~%" (binding-stack-usage))
+ #!+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*))
+ *gc-inhibit*))
(defun room-intermediate-info ()
(room-minimal-info)
(sb!vm:memory-usage :count-spaces '(:dynamic)
- :print-spaces t
- :cutoff 0.05f0
- :print-summary nil))
+ :print-spaces t
+ :cutoff 0.05f0
+ :print-summary nil))
(defun room-maximal-info ()
- (room-minimal-info)
- (sb!vm:memory-usage :count-spaces '(:static :dynamic))
- (sb!vm:instance-usage :dynamic :top-n 10)
- (sb!vm:instance-usage :static :top-n 10))
+ ;; FIXME: SB!VM:INSTANCE-USAGE calls suppressed until bug 344 is fixed
+ (room-intermediate-info)
+ ;; old way, could be restored when bug 344 fixed:
+ ;;x (room-minimal-info)
+ ;;x (sb!vm:memory-usage :count-spaces '(:static :dynamic))
+ ;;x (sb!vm:instance-usage :dynamic :top-n 10)
+ ;;x (sb!vm:instance-usage :static :top-n 10)
+ )
(defun room (&optional (verbosity :default))
#!+sb-doc
;;; allocated and never freed.)
(declaim (type unsigned-byte *n-bytes-freed-or-purified*))
(defvar *n-bytes-freed-or-purified* 0)
-(push (lambda ()
- (setf *n-bytes-freed-or-purified* 0))
- ;; KLUDGE: It's probably not quite safely right either to do
- ;; this in *BEFORE-SAVE-INITIALIZATIONS* (since consing, or even
- ;; worse, something which depended on (GET-BYTES-CONSED), might
- ;; happen after that) or in *AFTER-SAVE-INITIALIZATIONS*. But
- ;; it's probably not a big problem, and there seems to be no
- ;; other obvious time to do it. -- WHN 2001-07-30
- *after-save-initializations*)
-
-(declaim (ftype (function () unsigned-byte) get-bytes-consed))
+(defun gc-reinit ()
+ (setq *gc-inhibit* nil)
+ (gc)
+ (setf *n-bytes-freed-or-purified* 0
+ *gc-run-time* 0
+ ;; See comment in interr.lisp
+ *heap-exhausted-error-condition* (make-condition 'heap-exhausted-error)))
+
+(declaim (ftype (sfunction () unsigned-byte) get-bytes-consed))
(defun get-bytes-consed ()
#!+sb-doc
"Return the number of bytes consed since the program began. Typically
(+ (dynamic-usage)
*n-bytes-freed-or-purified*))
\f
-;;;; variables and constants
-
-;;; the minimum amount of dynamic space which must be consed before a
-;;; GC will be triggered
-;;;
-;;; Unlike CMU CL, we don't export this variable. (There's no need to,
-;;; since our BYTES-CONSED-BETWEEN-GCS function is SETFable.)
-(defvar *bytes-consed-between-gcs*
- #!+gencgc (* 4 (expt 10 6))
- ;; Stop-and-copy GC is really really slow when used too often. CSR
- ;; reported that even on his old 64 Mb SPARC, 20 Mb is much faster
- ;; than 4 Mb when rebuilding SBCL ca. 0.7.1. For modern machines
- ;; with >> 128 Mb memory, the optimum could be significantly more
- ;; than this, but at least 20 Mb should be better than 4 Mb.
- #!-gencgc (* 20 (expt 10 6)))
-(declaim (type index *bytes-consed-between-gcs*))
-
;;;; GC hooks
-(defvar *before-gc-hooks* nil ; actually initialized in cold init
- #!+sb-doc
- "A list of functions that are called before garbage collection occurs.
- The functions should take no arguments.")
-
-(defvar *after-gc-hooks* nil ; actually initialized in cold init
- #!+sb-doc
- "A list of functions that are called after garbage collection occurs.
- The functions should take no arguments.")
-
-(defvar *gc-notify-stream* nil ; (actually initialized in cold init)
- #!+sb-doc
- "When non-NIL, this must be a STREAM; and the functions bound to
- *GC-NOTIFY-BEFORE* and *GC-NOTIFY-AFTER* are called with the
- STREAM value before and after a garbage collection occurs
- respectively.")
-
-(defvar *gc-run-time* 0
- #!+sb-doc
- "the total CPU time spent doing garbage collection (as reported by
- GET-INTERNAL-RUN-TIME)")
-(declaim (type index *gc-run-time*))
+(defvar *after-gc-hooks* nil
+ "Called after each garbage collection, except for garbage collections
+triggered during thread exits. In a multithreaded environment these hooks may
+run in any thread.")
-;;; a limit to help catch programs which allocate too much memory,
-;;; since a hard heap overflow is so hard to recover from
-;;;
-;;; FIXME: Like *GC-TRIGGER*, this variable (1) should probably be
-;;; denominated in a larger unit than bytes and (2) should probably be
-;;; renamed so that it's clear from the name what unit it's
-;;; denominated in.
-(declaim (type (or unsigned-byte null) *soft-heap-limit*))
-(defvar *soft-heap-limit*
- ;; As long as *GC-TRIGGER* is DECLAIMed as INDEX, we know that
- ;; MOST-POSITIVE-FIXNUM is a hard limit on how much memory can be
- ;; allocated. (Not necessarily *the* hard limit, which is fairly
- ;; likely something like a Unix per-process limit that we don't know
- ;; about, but a hard limit anyway.) And this gives us a reasonable
- ;; conservative default for the soft limit...
- (- most-positive-fixnum
- *bytes-consed-between-gcs*))
-
-;;;; The following specials are used to control when garbage
-;;;; collection occurs.
-
-;;; When the dynamic usage increases beyond this amount, the system
-;;; notes that a garbage collection needs to occur by setting
-;;; *NEED-TO-COLLECT-GARBAGE* to T. It starts out as NIL meaning
-;;; nobody has figured out what it should be yet.
-;;;
-;;; FIXME: *GC-TRIGGER* seems to be denominated in bytes, not words.
-;;; And limiting it to INDEX is fairly reasonable in order to avoid
-;;; bignum arithmetic on every allocation, and to minimize the need
-;;; for thought about weird gotchas of the GC-control mechanism itself
-;;; consing as it operates. But as of sbcl-0.7.5, 512Mbytes of memory
-;;; costs $54.95 at Fry's in Dallas but cheap consumer 64-bit machines
-;;; are still over the horizon, so gratuitously limiting our heap size
-;;; to FIXNUM bytes seems fairly stupid. It'd be reasonable to
-;;; (1) allow arbitrary UNSIGNED-BYTE values of *GC-TRIGGER*, or
-;;; (2) redenominate this variable in words instead of bytes, postponing
-;;; the problem to heaps which exceed 50% of the machine's address
-;;; space, or even
-;;; (3) redemoninate this variable in CONS-sized two-word units,
-;;; allowing it to cover the entire memory space at the price of
-;;; possible loss of clarity.
-;;; (And whatever is done, it'd also be good to rename the variable so
-;;; that it's clear what unit it's denominated in.)
-(declaim (type (or index null) *gc-trigger*))
-(defvar *gc-trigger* nil)
-
-;;; When non-NIL, inhibits garbage collection.
-(defvar *gc-inhibit*) ; initialized in cold init
-
-;;; This flag is used to prevent recursive entry into the garbage
-;;; collector.
-(defvar *already-maybe-gcing*) ; initialized in cold init
-
-;;; When T, indicates that the dynamic usage has exceeded the value
-;;; *GC-TRIGGER*.
-(defvar *need-to-collect-garbage* nil) ; initialized in cold init
-\f
-(defun default-gc-notify-before (notify-stream bytes-in-use)
- (declare (type stream notify-stream))
- (format
- notify-stream
- "~&; GC is beginning with ~:D bytes in use at internal runtime ~:D.~%"
- bytes-in-use
- (get-internal-run-time))
- (finish-output notify-stream))
-(defparameter *gc-notify-before* #'default-gc-notify-before
- #!+sb-doc
- "The function bound to this variable is invoked before GC'ing (unless
- *GC-NOTIFY-STREAM* is NIL) with the value of *GC-NOTIFY-STREAM* and
- current amount of dynamic usage (in bytes). It should notify the
- user that the system is going to GC.")
-
-(defun default-gc-notify-after (notify-stream
- bytes-retained
- bytes-freed
- new-trigger)
- (declare (type stream notify-stream))
- (format notify-stream
- "~&; GC has finished with ~:D bytes in use (~:D bytes freed)~@
- ; at internal runtime ~:D. The new GC trigger is ~:D bytes.~%"
- bytes-retained
- bytes-freed
- (get-internal-run-time)
- new-trigger)
- (finish-output notify-stream))
-(defparameter *gc-notify-after* #'default-gc-notify-after
- #!+sb-doc
- "The function bound to this variable is invoked after GC'ing with the
-value of *GC-NOTIFY-STREAM*, the amount of dynamic usage (in bytes) now
-free, the number of bytes freed by the GC, and the new GC trigger
-threshold; or if *GC-NOTIFY-STREAM* is NIL, it's not invoked. The
-function should notify the user that the system has finished GC'ing.")
\f
;;;; internal GC
(sb!alien:define-alien-routine collect-garbage sb!alien:int
- #!+gencgc (last-gen sb!alien:int))
-
-(sb!alien:define-alien-routine set-auto-gc-trigger sb!alien:void
- (dynamic-usage sb!alien:unsigned-long))
+ (#!+gencgc last-gen #!-gencgc ignore sb!alien:int))
-(sb!alien:define-alien-routine clear-auto-gc-trigger sb!alien:void)
+#!+sb-thread
+(progn
+ (sb!alien:define-alien-routine gc-stop-the-world sb!alien:void)
+ (sb!alien:define-alien-routine gc-start-the-world sb!alien:void))
+#!-sb-thread
+(progn
+ (defun gc-stop-the-world ())
+ (defun gc-start-the-world ()))
-;;; This variable contains the function that does the real GC. This is
-;;; for low-level GC experimentation. Do not touch it if you do not
-;;; know what you are doing.
-(defvar *internal-gc* #'collect-garbage)
+#!+gencgc
+(progn
+ (sb!alien:define-alien-variable ("gc_logfile" %gc-logfile) (* char))
+ (defun (setf gc-logfile) (pathname)
+ (let ((new (when pathname
+ (sb!alien:make-alien-string
+ (native-namestring (translate-logical-pathname pathname)
+ :as-file t))))
+ (old %gc-logfile))
+ (setf %gc-logfile new)
+ (when old
+ (sb!alien:free-alien old))
+ pathname))
+ (defun gc-logfile ()
+ #!+sb-doc
+ "Return the pathname used to log garbage collections. Can be SETF.
+Default is NIL, meaning collections are not logged. If non-null, the
+designated file is opened before and after each collection, and generation
+statistics are appended to it."
+ (let ((val (cast %gc-logfile c-string)))
+ (when val
+ (native-pathname val))))
+ (declaim (inline dynamic-space-size))
+ (defun dynamic-space-size ()
+ "Size of the dynamic space in bytes."
+ (sb!alien:extern-alien "dynamic_space_size" os-vm-size-t)))
\f
;;;; SUB-GC
-;;; This is used to carefully invoke hooks.
-(eval-when (:compile-toplevel :execute)
- (sb!xc:defmacro carefully-funcall (function &rest args)
- `(handler-case (funcall ,function ,@args)
- (error (cond)
- (warn "(FUNCALL ~S~{ ~S~}) lost:~%~A" ',function ',args cond)
- nil))))
-
-;;; SUB-GC decides when and if to do a garbage collection. The FORCE-P
-;;; flags controls whether a GC should occur even if the dynamic usage
-;;; is not greater than *GC-TRIGGER*.
+;;; SUB-GC does a garbage collection. This is called from three places:
+;;; (1) The C runtime will call here when it detects that we've consed
+;;; enough to exceed the gc trigger threshold. This is done in
+;;; alloc() for gencgc or interrupt_maybe_gc() for cheneygc
+;;; (2) The user may request a collection using GC, below
+;;; (3) At the end of a WITHOUT-GCING section, we are called if
+;;; *NEED-TO-COLLECT-GARBAGE* is true
;;;
+;;; This is different from the behaviour in 0.7 and earlier: it no
+;;; longer decides whether to GC based on thresholds. If you call
+;;; SUB-GC you will definitely get a GC either now or when the
+;;; WITHOUT-GCING is over
+
;;; For GENCGC all generations < GEN will be GC'ed.
-(defun sub-gc (&key force-p (gen 0))
- (/show0 "entering SUB-GC")
- (unless *already-maybe-gcing*
- (let* ((*already-maybe-gcing* t)
- (start-time (get-internal-run-time))
- (pre-gc-dynamic-usage (dynamic-usage))
- ;; Currently we only check *SOFT-HEAP-LIMIT* at GC time,
- ;; not for every allocation. That makes it cheap to do,
- ;; even if it is a little ugly.
- (soft-heap-limit-exceeded? (and *soft-heap-limit*
- (> pre-gc-dynamic-usage
- *soft-heap-limit*)))
- (*soft-heap-limit* (if soft-heap-limit-exceeded?
- (+ pre-gc-dynamic-usage
- *bytes-consed-between-gcs*)
- *soft-heap-limit*)))
- (when soft-heap-limit-exceeded?
- (cerror "Continue with GC."
- "soft heap limit exceeded (temporary new limit=~W)"
- *soft-heap-limit*))
- (when (and *gc-trigger* (> pre-gc-dynamic-usage *gc-trigger*))
- (setf *need-to-collect-garbage* t))
- (when (or force-p
- (and *need-to-collect-garbage* (not *gc-inhibit*)))
- ;; KLUDGE: Wow, we really mask interrupts all the time we're
- ;; collecting garbage? That seems like a long time.. -- WHN 19991129
- (without-interrupts
- ;; FIXME: We probably shouldn't do this evil thing to
- ;; *STANDARD-OUTPUT* in a binding which is wrapped around
- ;; calls to user-settable GC hook functions.
- (let ((*standard-output* *terminal-io*))
- (when *gc-notify-stream*
- (if (streamp *gc-notify-stream*)
- (carefully-funcall *gc-notify-before*
- *gc-notify-stream*
- pre-gc-dynamic-usage)
- (warn
- "*GC-NOTIFY-STREAM* is set, but not a STREAM -- ignored.")))
- (dolist (hook *before-gc-hooks*)
- (carefully-funcall hook))
- (when *gc-trigger*
- (clear-auto-gc-trigger))
- (let* (;; We do DYNAMIC-USAGE once more here in order to
- ;; get a more accurate measurement of the space
- ;; actually freed, since the messing around, e.g.
- ;; GC-notify stuff, since the DYNAMIC-USAGE which
- ;; triggered GC could've done a fair amount of
- ;; consing.)
- (pre-internal-gc-dynamic-usage (dynamic-usage))
- (ignore-me
- #!-gencgc (funcall *internal-gc*)
- ;; FIXME: This EQ test is pretty gross. Among its other
- ;; nastinesses, it looks as though it could break if we
- ;; recompile COLLECT-GARBAGE. We should probably just
- ;; straighten out the interface so that all *INTERNAL-GC*
- ;; functions accept a GEN argument (and then the
- ;; non-generational ones just ignore it).
- #!+gencgc (if (eq *internal-gc* #'collect-garbage)
- (funcall *internal-gc* gen)
- (funcall *internal-gc*)))
- (post-gc-dynamic-usage (dynamic-usage))
- (n-bytes-freed (- pre-internal-gc-dynamic-usage
- post-gc-dynamic-usage))
- ;; In sbcl-0.6.12.39, the raw N-BYTES-FREED from
- ;; GENCGC could sometimes be substantially negative
- ;; (e.g. -5872). I haven't looked into what causes
- ;; that, but I suspect it has to do with
- ;; fluctuating inefficiency in the way that the
- ;; GENCGC packs things into page boundaries.
- ;; Bumping the raw result up to 0 is a little ugly,
- ;; but shouldn't be a problem, and it's even
- ;; possible to sort of justify it: the packing
- ;; inefficiency which has caused (DYNAMIC-USAGE) to
- ;; grow is effectively consing, or at least
- ;; overhead of consing, so it's sort of correct to
- ;; add it to the running total of consing. ("Man
- ;; isn't a rational animal, he's a rationalizing
- ;; animal.":-) -- WHN 2001-06-23
- (eff-n-bytes-freed (max 0 n-bytes-freed)))
- (declare (ignore ignore-me))
- (/show0 "got (DYNAMIC-USAGE) and EFF-N-BYTES-FREED")
- (incf *n-bytes-freed-or-purified*
- eff-n-bytes-freed)
- (/show0 "clearing *NEED-TO-COLLECT-GARBAGE*")
- (setf *need-to-collect-garbage* nil)
- (/show0 "calculating NEW-GC-TRIGGER")
- (let ((new-gc-trigger (+ post-gc-dynamic-usage
- *bytes-consed-between-gcs*)))
- (/show0 "setting *GC-TRIGGER*")
- (setf *gc-trigger* new-gc-trigger))
- (/show0 "calling SET-AUTO-GC-TRIGGER")
- (set-auto-gc-trigger *gc-trigger*)
- (dolist (hook *after-gc-hooks*)
- (/show0 "doing a hook from *AFTER-GC--HOOKS*")
- ;; FIXME: This hook should be called with the same
- ;; kind of information as *GC-NOTIFY-AFTER*. In
- ;; particular, it would be nice for the hook function
- ;; to be able to adjust *GC-TRIGGER* intelligently to
- ;; e.g. 108% of total memory usage.
- (carefully-funcall hook))
- (when *gc-notify-stream*
- (if (streamp *gc-notify-stream*)
- (carefully-funcall *gc-notify-after*
- *gc-notify-stream*
- post-gc-dynamic-usage
- eff-n-bytes-freed
- *gc-trigger*)
- (warn
- "*GC-NOTIFY-STREAM* is set, but not a stream -- ignored.")))))
- (scrub-control-stack))) ;XXX again? we did this from C ...
- (incf *gc-run-time* (- (get-internal-run-time)
- start-time))))
- ;; FIXME: should probably return (VALUES), here and in RETURN-FROM
- nil)
-
-;;; This routine is called by the allocation miscops to decide whether
-;;; a GC should occur. The argument, OBJECT, is the newly allocated
-;;; object which must be returned to the caller.
-(defun maybe-gc (&optional object)
- (sub-gc)
- object)
+
+(defvar *already-in-gc* (sb!thread:make-mutex :name "GC lock"))
+
+;;; A unique GC id. This is supplied for code that needs to detect
+;;; whether a GC has happened since some earlier point in time. For
+;;; example:
+;;;
+;;; (let ((epoch *gc-epoch*))
+;;; ...
+;;; (unless (eql epoch *gc-epoch)
+;;; ....))
+;;;
+;;; This isn't just a fixnum counter since then we'd have theoretical
+;;; problems when exactly 2^29 GCs happen between epoch
+;;; comparisons. Unlikely, but the cost of using a cons instead is too
+;;; small to measure. -- JES, 2007-09-30
+(declaim (type cons *gc-epoch*))
+(defvar *gc-epoch* (cons nil nil))
+
+(defun sub-gc (&key (gen 0))
+ (cond (*gc-inhibit*
+ (setf *gc-pending* t)
+ nil)
+ (t
+ (flet ((perform-gc ()
+ ;; Called from WITHOUT-GCING and WITHOUT-INTERRUPTS
+ ;; after the world has been stopped, but it's an
+ ;; awkwardly long piece of code to nest so deeply.
+ (let ((old-usage (dynamic-usage))
+ (new-usage 0)
+ (start-time (get-internal-run-time)))
+ (collect-garbage gen)
+ (setf *gc-epoch* (cons nil nil))
+ (let ((run-time (- (get-internal-run-time) start-time)))
+ ;; KLUDGE: Sometimes we see the second getrusage() call
+ ;; return a smaller value than the first, which can
+ ;; lead to *GC-RUN-TIME* to going negative, which in
+ ;; turn is a type-error.
+ (when (plusp run-time)
+ (incf *gc-run-time* run-time)))
+ #!+sb-safepoint
+ (setf *stop-for-gc-pending* nil)
+ (setf *gc-pending* nil
+ new-usage (dynamic-usage))
+ #!+sb-thread
+ (assert (not *stop-for-gc-pending*))
+ (gc-start-the-world)
+ ;; In a multithreaded environment the other threads
+ ;; will see *n-b-f-o-p* change a little late, but
+ ;; that's OK.
+ ;; N.B. the outer without-gcing prevents this
+ ;; function from being entered, so no need for
+ ;; locking.
+ (let ((freed (- old-usage new-usage)))
+ ;; GENCGC occasionally reports negative here, but
+ ;; the current belief is that it is part of the
+ ;; normal order of things and not a bug.
+ (when (plusp freed)
+ (incf *n-bytes-freed-or-purified* freed))))))
+ (declare (inline perform-gc))
+ ;; Let's make sure we're not interrupted and that none of
+ ;; the deadline or deadlock detection stuff triggers.
+ (without-interrupts
+ (sb!thread::without-thread-waiting-for
+ (:already-without-interrupts t)
+ (let ((sb!impl::*deadline* nil)
+ (sb!impl::*deadline-seconds* nil)
+ (epoch *gc-epoch*))
+ (loop
+ ;; GCing must be done without-gcing to avoid
+ ;; recursive GC... but we can't block on
+ ;; *already-in-gc* inside without-gcing: that would
+ ;; cause a deadlock.
+ (without-gcing
+ ;; Try to grab that mutex. On acquisition, stop
+ ;; the world from with the mutex held, and then
+ ;; execute the remainder of the GC: stopping the
+ ;; world with interrupts disabled is the mother of
+ ;; all critical sections.
+ (cond ((sb!thread:with-mutex (*already-in-gc* :wait-p nil)
+ (unsafe-clear-roots gen)
+ (gc-stop-the-world)
+ t)
+ ;; Success! GC.
+ (perform-gc)
+ ;; Return, but leave *gc-pending* as is: we
+ ;; did allocate a tiny bit after GCing. In
+ ;; theory, this could lead to a long chain
+ ;; of tail-recursive (but not in explicit
+ ;; tail position) GCs, but that doesn't
+ ;; seem likely to happen too often... And
+ ;; the old code already suffered from this
+ ;; problem.
+ (return t))
+ (t
+ ;; Some other thread is trying to GC. Clear
+ ;; *gc-pending* (we already know we want a
+ ;; GC to happen) and either let
+ ;; without-gcing figure out that the world
+ ;; is stopping, or try again.
+ (setf *gc-pending* nil))))
+ ;; we just wanted a minor GC, and a GC has
+ ;; occurred. Leave, but don't execute after-gc
+ ;; hooks.
+ ;;
+ ;; Return a 0 for easy ternary logic in the C
+ ;; runtime.
+ (when (and (eql gen 0)
+ (neq epoch *gc-pending*))
+ (return 0))))))))))
+
+(defun post-gc ()
+ ;; Outside the mutex, interrupts may be enabled: these may cause
+ ;; another GC. FIXME: it can potentially exceed maximum interrupt
+ ;; nesting by triggering GCs.
+ ;;
+ ;; Can that be avoided by having the finalizers and hooks run only
+ ;; from the outermost SUB-GC? If the nested GCs happen in interrupt
+ ;; handlers that's not enough.
+ ;;
+ ;; KLUDGE: Don't run the hooks in GC's if:
+ ;;
+ ;; A) this thread is dying, so that user-code never runs with
+ ;; (thread-alive-p *current-thread*) => nil
+ ;;
+ ;; B) interrupts are disabled somewhere up the call chain since we
+ ;; don't want to run user code in such a case.
+ ;;
+ ;; The long-term solution will be to keep a separate thread for
+ ;; finalizers and after-gc hooks.
+ (when (sb!thread:thread-alive-p sb!thread:*current-thread*)
+ (when *allow-with-interrupts*
+ (sb!thread::without-thread-waiting-for ()
+ (with-interrupts
+ (run-pending-finalizers)
+ (call-hooks "after-GC" *after-gc-hooks* :on-error :warn))))))
;;; This is the user-advertised garbage collection function.
-(defun gc (&key (gen 0) (full nil) &allow-other-keys)
+(defun gc (&key (full nil) (gen 0) &allow-other-keys)
#!+(and sb-doc gencgc)
- "Initiate a garbage collection. GEN controls the number of generations
- to garbage collect."
- #!+(and sb-doc (not gencgc))
- "Initiate a garbage collection. GEN may be provided for compatibility with
- generational garbage collectors, but is ignored in this implementation."
- (sub-gc :force-p t :gen (if full 6 gen)))
+ "Initiate a garbage collection.
+The default is to initiate a nursery collection, which may in turn
+trigger a collection of one or more older generations as well. If FULL
+is true, all generations are collected. If GEN is provided, it can be
+used to specify the oldest generation guaranteed to be collected.
+
+On CheneyGC platforms arguments FULL and GEN take no effect: a full
+collection is always preformed."
+ #!+(and sb-doc (not gencgc))
+ "Initiate a garbage collection.
+
+The collection is always a full collection.
+
+Arguments FULL and GEN can be used for compatibility with GENCGC
+platforms: there the default is to initiate a nursery collection,
+which may in turn trigger a collection of one or more older
+generations as well. If FULL is true, all generations are collected.
+If GEN is provided, it can be used to specify the oldest generation
+guaranteed to be collected."
+ (when (eq t (sub-gc :gen (if full sb!vm:+pseudo-static-generation+ gen)))
+ (post-gc)))
+
+(define-alien-routine scrub-control-stack sb!alien:void)
+
+(defun unsafe-clear-roots (gen)
+ #!-gencgc (declare (ignore gen))
+ ;; KLUDGE: Do things in an attempt to get rid of extra roots. Unsafe
+ ;; as having these cons more then we have space left leads to huge
+ ;; badness.
+ (scrub-control-stack)
+ ;; Power cache of the bignum printer: drops overly large bignums and
+ ;; removes duplicate entries.
+ (scrub-power-cache)
+ ;; Clear caches depending on the generation being collected.
+ #!+gencgc
+ (cond ((eql 0 gen))
+ ((eql 1 gen)
+ (ctype-of-cache-clear))
+ (t
+ (drop-all-hash-caches)))
+ #!-gencgc
+ (drop-all-hash-caches))
\f
;;;; auxiliary functions
(defun bytes-consed-between-gcs ()
#!+sb-doc
- "Return the amount of memory that will be allocated before the next garbage
- collection is initiated. This can be set with SETF."
- *bytes-consed-between-gcs*)
+ "The amount of memory that will be allocated before the next garbage
+collection is initiated. This can be set with SETF.
+
+On GENCGC platforms this is the nursery size, and defaults to 5% of dynamic
+space size.
+
+Note: currently changes to this value are lost when saving core."
+ (sb!alien:extern-alien "bytes_consed_between_gcs" os-vm-size-t))
+
(defun (setf bytes-consed-between-gcs) (val)
- ;; FIXME: Shouldn't this (and the DECLAIM for the underlying variable)
- ;; be for a strictly positive number type, e.g.
- ;; (AND (INTEGER 1) FIXNUM)?
(declare (type index val))
- (let ((old *bytes-consed-between-gcs*))
- (setf *bytes-consed-between-gcs* val)
- (when *gc-trigger*
- (setf *gc-trigger* (+ *gc-trigger* (- val old)))
- (cond ((<= (dynamic-usage) *gc-trigger*)
- (clear-auto-gc-trigger)
- (set-auto-gc-trigger *gc-trigger*))
- (t
- ;; FIXME: If SCRUB-CONTROL-STACK is required here, why
- ;; isn't it built into SUB-GC? And *is* it required here?
- (sb!sys:scrub-control-stack)
- (sub-gc)))))
- val)
-
-(defun gc-on ()
- #!+sb-doc
- "Enable the garbage collector."
- (setq *gc-inhibit* nil)
- (when *need-to-collect-garbage*
- (sub-gc))
- nil)
+ (setf (sb!alien:extern-alien "bytes_consed_between_gcs" os-vm-size-t)
+ val))
-(defun gc-off ()
- #!+sb-doc
- "Disable the garbage collector."
- (setq *gc-inhibit* t)
- nil)
-\f
-;;;; initialization stuff
+(declaim (inline maybe-handle-pending-gc))
+(defun maybe-handle-pending-gc ()
+ (when (and (not *gc-inhibit*)
+ (or #!+sb-thread *stop-for-gc-pending*
+ *gc-pending*))
+ (sb!unix::receive-pending-interrupt)))
-(defun gc-reinit ()
- (when *gc-trigger*
- (if (< *gc-trigger* (dynamic-usage))
- (sub-gc)
- (set-auto-gc-trigger *gc-trigger*))))
+;;;; GENCGC specifics
+;;;;
+;;;; For documentation convenience, these have stubs on non-GENCGC platforms
+;;;; as well.
+#!+gencgc
+(deftype generation-index ()
+ '(integer 0 #.sb!vm:+pseudo-static-generation+))
+
+;;; FIXME: GENERATION (and PAGE, as seen in room.lisp) should probably be
+;;; defined in Lisp, and written to header files by genesis, instead of this
+;;; OAOOMiness -- this duplicates the struct definition in gencgc.c.
+#!+gencgc
+(define-alien-type generation
+ (struct generation
+ (alloc-start-page page-index-t)
+ (alloc-unboxed-start-page page-index-t)
+ (alloc-large-start-page page-index-t)
+ (alloc-large-unboxed-start-page page-index-t)
+ (bytes-allocated os-vm-size-t)
+ (gc-trigger os-vm-size-t)
+ (bytes-consed-between-gcs os-vm-size-t)
+ (number-of-gcs int)
+ (number-of-gcs-before-promotion int)
+ (cum-sum-bytes-allocated os-vm-size-t)
+ (minimum-age-before-gc double)))
+
+#!+gencgc
+(define-alien-variable generations
+ (array generation #.(1+ sb!vm:+pseudo-static-generation+)))
+
+(macrolet ((def (slot doc &optional setfp)
+ (declare (ignorable doc))
+ `(progn
+ (defun ,(symbolicate "GENERATION-" slot) (generation)
+ #!+sb-doc
+ ,doc
+ #!+gencgc
+ (declare (generation-index generation))
+ #!-gencgc
+ (declare (ignore generation))
+ #!-gencgc
+ (error "~S is a GENCGC only function and unavailable in this build"
+ ',slot)
+ #!+gencgc
+ (slot (deref generations generation) ',slot))
+ ,@(when setfp
+ `((defun (setf ,(symbolicate "GENERATION-" slot)) (value generation)
+ #!+gencgc
+ (declare (generation-index generation))
+ #!-gencgc
+ (declare (ignore value generation))
+ #!-gencgc
+ (error "(SETF ~S) is a GENCGC only function and unavailable in this build"
+ ',slot)
+ #!+gencgc
+ (setf (slot (deref generations generation) ',slot) value)))))))
+ (def bytes-consed-between-gcs
+ "Number of bytes that can be allocated to GENERATION before that
+generation is considered for garbage collection. This value is meaningless for
+generation 0 (the nursery): see BYTES-CONSED-BETWEEN-GCS instead. Default is
+5% of the dynamic space size divided by the number of non-nursery generations.
+Can be assigned to using SETF. Available on GENCGC platforms only.
+
+Experimental: interface subject to change."
+ t)
+ (def minimum-age-before-gc
+ "Minimum average age of objects allocated to GENERATION before that
+generation is may be garbage collected. Default is 0.75. See also
+GENERATION-AVERAGE-AGE. Can be assigned to using SETF. Available on GENCGC
+platforms only.
+
+Experimental: interface subject to change."
+ t)
+ (def number-of-gcs-before-promotion
+ "Number of times garbage collection is done on GENERATION before
+automatic promotion to the next generation is triggered. Default is 1. Can be
+assigned to using SETF. Available on GENCGC platforms only.
+
+Experimental: interface subject to change."
+ t)
+ (def bytes-allocated
+ "Number of bytes allocated to GENERATION currently. Available on GENCGC
+platforms only.
+
+Experimental: interface subject to change.")
+ (def number-of-gcs
+ "Number of times garbage collection has been done on GENERATION without
+promotion. Available on GENCGC platforms only.
+
+Experimental: interface subject to change."))
+ (defun generation-average-age (generation)
+ "Average age of memory allocated to GENERATION: average number of times
+objects allocated to the generation have seen younger objects promoted to it.
+Available on GENCGC platforms only.
+
+Experimental: interface subject to change."
+ #!+gencgc
+ (declare (generation-index generation))
+ #!-gencgc (declare (ignore generation))
+ #!-gencgc
+ (error "~S is a GENCGC only function and unavailable in this build."
+ 'generation-average-age)
+ #!+gencgc
+ (alien-funcall (extern-alien "generation_average_age"
+ (function double generation-index-t))
+ generation))
projects / sbcl.git / blobdiff