X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fgc.lisp;h=1acfa9cce24a680c8f9f171ff249902b3b684a54;hb=568214ddf4c8ecc881caec98e20848d017974ec0;hp=39d59a63ab097d8d02686bc62fcb386ef786ed1f;hpb=02c9007b4ca5753406f60019f4fe5e5f8392541a;p=sbcl.git diff --git a/src/code/gc.lisp b/src/code/gc.lisp index 39d59a6..1acfa9c 100644 --- a/src/code/gc.lisp +++ b/src/code/gc.lisp @@ -17,24 +17,21 @@ 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!xc:defmacro def-c-var-fun (lisp-fun c-var-name) + `(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")) +(def-c-var-fun current-dynamic-space-start "current_dynamic_space") #!-sb-fluid -(declaim (inline dynamic-usage)) ; to reduce PROFILEd call overhead +(declaim (inline dynamic-usage)) #!+gencgc -(def-c-var-frob dynamic-usage "bytes_allocated") +(def-c-var-fun dynamic-usage "bytes_allocated") #!-gencgc (defun dynamic-usage () (the (unsigned-byte 32) @@ -52,14 +49,14 @@ (defun control-stack-usage () #!-stack-grows-downward-not-upward (- (sb!sys:sap-int (sb!c::control-stack-pointer-sap)) - (sb!vm:fixnumize sb!vm::*control-stack-start*)) + (sb!vm:fixnumize sb!vm:*control-stack-start*)) #!+stack-grows-downward-not-upward - (- (sb!vm:fixnumize sb!vm::*control-stack-end*) + (- (sb!vm:fixnumize 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:fixnumize sb!vm::*binding-stack-start*))) + (sb!vm:fixnumize sb!vm:*binding-stack-start*))) ;;;; ROOM @@ -83,10 +80,14 @@ :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 @@ -116,15 +117,10 @@ ;;; 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*) +(defun gc-reinit () + (gc-on) + (gc) + (setf *n-bytes-freed-or-purified* 0)) (declaim (ftype (function () unsigned-byte) get-bytes-consed)) (defun get-bytes-consed () @@ -138,47 +134,11 @@ and submit it as a patch." (+ (dynamic-usage) *n-bytes-freed-or-purified*)) -;;;; 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. In a multithreaded +environment these hooks may run in any thread.") ;;;; The following specials are used to control when garbage ;;;; collection occurs. @@ -208,9 +168,6 @@ and submit it as a patch." (declaim (type (or index null) *gc-trigger*)) (defvar *gc-trigger* nil) -;;; When >0, inhibits garbage collection. -(defvar *gc-inhibit*) ; initialized in cold init - ;;; When T, indicates that a GC should have happened but did not due to ;;; *GC-INHIBIT*. (defvar *need-to-collect-garbage* nil) ; initialized in cold init @@ -220,40 +177,22 @@ and submit it as a patch." (sb!alien:define-alien-routine collect-garbage sb!alien:int (#!+gencgc last-gen #!-gencgc ignore sb!alien:int)) -(sb!alien:define-alien-routine set-auto-gc-trigger sb!alien:void - (dynamic-usage sb!alien:unsigned-long)) - -(sb!alien:define-alien-routine clear-auto-gc-trigger sb!alien:void) - -#!+sb-thread -(def-c-var-frob gc-thread-pid "gc_thread_pid") #!+sb-thread -(defun other-thread-collect-garbage (gen) - (setf (sb!alien:extern-alien "maybe_gc_pending" (sb!alien:unsigned 32)) - (1+ gen)) - (sb!unix:unix-kill (gc-thread-pid) :SIGALRM)) - -;;; 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* - #!+sb-thread #'other-thread-collect-garbage - #!-sb-thread #'collect-garbage) - +(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 ())) + ;;;; 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 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 +;;; 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 @@ -265,47 +204,47 @@ and submit it as a patch." ;;; For GENCGC all generations < GEN will be GC'ed. -(defvar *gc-mutex* (sb!thread:make-mutex :name "GC Mutex")) +(defvar *already-in-gc* + (sb!thread:make-mutex :name "GC lock") "ID of thread running SUB-GC") (defun sub-gc (&key (gen 0)) - (when (sb!thread::mutex-value *gc-mutex*) (return-from sub-gc nil)) - (sb!thread:with-mutex (*gc-mutex* :wait-p nil) - (let* ((start-time (get-internal-run-time))) - (setf *need-to-collect-garbage* t) - (when (zerop *gc-inhibit*) - (without-interrupts - (dolist (hook *before-gc-hooks*) (carefully-funcall hook)) - (when *gc-trigger* - (clear-auto-gc-trigger)) - (let* ((pre-internal-gc-dynamic-usage (dynamic-usage)) - (ignore-me (funcall *internal-gc* gen)) - (post-gc-dynamic-usage (dynamic-usage)) - (n-bytes-freed (- pre-internal-gc-dynamic-usage - post-gc-dynamic-usage)) - ;; the raw N-BYTES-FREED from GENCGC can sometimes be - ;; substantially negative (e.g. -5872). This is - ;; probably due to fluctuating inefficiency in the way - ;; that the GENCGC packs things into page boundaries. - ;; We bump the raw result up to 0: the space is - ;; allocated even if unusable, so should be counted - ;; for deciding when we've allocated enough to GC - ;; next. ("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)) - (incf *n-bytes-freed-or-purified* eff-n-bytes-freed) - (setf *need-to-collect-garbage* nil) - (setf *gc-trigger* (+ post-gc-dynamic-usage - *bytes-consed-between-gcs*)) - (set-auto-gc-trigger *gc-trigger*) - (dolist (hook *after-gc-hooks*) - (carefully-funcall hook)))) - (scrub-control-stack)) ;XXX again? we did this from C ... - (incf *gc-run-time* (- (get-internal-run-time) start-time)))) - nil) - - - + (unless (eq sb!thread:*current-thread* + (sb!thread::mutex-value *already-in-gc*)) + ;; With gencgc, unless *NEED-TO-COLLECT-GARBAGE* every allocation + ;; in this function triggers another gc, potentially exceeding + ;; maximum interrupt nesting. + (setf *need-to-collect-garbage* t) + (when (zerop *gc-inhibit*) + (sb!thread:with-mutex (*already-in-gc*) + (let ((old-usage (dynamic-usage)) + (new-usage 0)) + (unsafe-clear-roots) + ;; We need to disable interrupts for GC, but we also want + ;; to run as little as possible without them. + (without-interrupts + (gc-stop-the-world) + (collect-garbage gen) + (setf *need-to-collect-garbage* nil + new-usage (dynamic-usage)) + (gc-start-the-world)) + ;; Interrupts re-enabled, but still inside the mutex. + ;; In a multithreaded environment the other threads will + ;; see *n-b-f-o-p* change a little late, but that's OK. + (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))))) + ;; Outside the mutex, these may cause another GC. FIXME: it can + ;; potentially exceed maximum interrupt nesting by triggering + ;; GCs. + (run-pending-finalizers) + (dolist (hook *after-gc-hooks*) + (handler-case + (funcall hook) + (error (c) + (warn "Error calling after GC hook ~S:~% ~S" hook c))))))) ;;; This is the user-advertised garbage collection function. (defun gc (&key (gen 0) (full nil) &allow-other-keys) @@ -315,7 +254,16 @@ and submit it as a patch." #!+(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 :gen (if full 6 gen))) + (sub-gc :gen (if full 6 gen))) + +(defun unsafe-clear-roots () + ;; 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) + ;; FIXME: CTYPE-OF-CACHE-CLEAR isn't thread-safe. + #!-sb-thread + (ctype-of-cache-clear)) ;;;; auxiliary functions @@ -324,26 +272,18 @@ and submit it as a patch." #!+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*) + (sb!alien:extern-alien "bytes_consed_between_gcs" + (sb!alien:unsigned 32))) + (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) + (setf (sb!alien:extern-alien "bytes_consed_between_gcs" + (sb!alien:unsigned 32)) + val)) +;;; FIXME: Aren't these utterly wrong if called inside WITHOUT-GCING? +;;; Unless something that works there too can be deviced this fact +;;; should be documented. (defun gc-on () #!+sb-doc "Enable the garbage collector." @@ -357,11 +297,3 @@ and submit it as a patch." "Disable the garbage collector." (setq *gc-inhibit* 1) nil) - -;;;; initialization stuff - -(defun gc-reinit () - (when *gc-trigger* - (if (< *gc-trigger* (dynamic-usage)) - (sub-gc) - (set-auto-gc-trigger *gc-trigger*))))