-;;; XXX need (1) some kind of locking to ensure that only one thread
-;;; at a time is trying to GC, (2) to look at all these specials and
-;;; work out how much of this "do we really need to GC now?" stuff is
-;;; actually necessary: I think we actually end up GCing every time we
-;;; hit this code
-
-(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* (zerop *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 (funcall *internal-gc* gen))
- (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)