X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fgc.lisp;h=7ba3b3b3e05f7e3a2e50819992006df7b7018cec;hb=7a0f4c68d94ff6c9a54c7605b6fd3cd8125c1c8c;hp=c0c7b022b84775acbccbaff7dbbeb2ff4cd8c2a8;hpb=96a5ccbf2930180fbcfae8d286acbd7416b00af8;p=sbcl.git

diff --git a/src/code/gc.lisp b/src/code/gc.lisp
index c0c7b02..7ba3b3b 100644
--- a/src/code/gc.lisp
+++ b/src/code/gc.lisp
@@ -180,9 +180,25 @@ run in any thread.")
 (defvar *already-in-gc*
   (sb!thread:make-mutex :name "GC lock") "ID of thread running SUB-GC")
 
+;;; 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))
   (unless (eq sb!thread:*current-thread*
-              (sb!thread::mutex-value *already-in-gc*))
+              (sb!thread:mutex-value *already-in-gc*))
     ;; With gencgc, unless *GC-PENDING* every allocation in this
     ;; function triggers another gc, potentially exceeding maximum
     ;; interrupt nesting. If *GC-INHIBIT* is not true, however,
@@ -202,6 +218,7 @@ run in any thread.")
                  (gc-stop-the-world)
                  (let ((start-time (get-internal-run-time)))
                    (collect-garbage gen)
+                   (setf *gc-epoch* (cons nil nil))
                    (incf *gc-run-time*
                          (- (get-internal-run-time) start-time)))
                  (setf *gc-pending* nil
@@ -252,6 +269,9 @@ run in any thread.")
   ;; 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)
   ;; FIXME: CTYPE-OF-CACHE-CLEAR isn't thread-safe.
   #!-sb-thread
   (ctype-of-cache-clear))