(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
;;; For GENCGC all generations < GEN will be GC'ed.
-(defvar *already-in-gc* nil "System is running SUB-GC")
-(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) &aux (pre-gc-dynamic-usage (dynamic-usage)))
- (when *already-in-gc* (return-from sub-gc nil))
- (setf *need-to-collect-garbage* t)
- (when (zerop *gc-inhibit*)
- (sb!thread:with-recursive-lock (*gc-mutex*)
- (let ((*already-in-gc* t))
- (without-interrupts
- (gc-stop-the-world)
- (dolist (h *before-gc-hooks*)
- (carefully-funcall h))
- (collect-garbage gen)
- (incf *n-bytes-freed-or-purified*
- (max 0 (- pre-gc-dynamic-usage (dynamic-usage))))
- (setf *need-to-collect-garbage* nil)
- (dolist (h *after-gc-hooks*)
- (carefully-funcall h))
- (gc-start-the-world)))
- (scrub-control-stack)))
- (values))
-
-
+ (let ((me (sb!thread:current-thread-id)))
+ (when (eql (sb!thread::mutex-value *already-in-gc*) me)
+ (return-from sub-gc nil))
+ (setf *need-to-collect-garbage* t)
+ (when (zerop *gc-inhibit*)
+ (loop
+ (sb!thread:with-mutex (*already-in-gc*)
+ (unless *need-to-collect-garbage* (return-from sub-gc nil))
+ (without-interrupts
+ (gc-stop-the-world)
+ (collect-garbage gen)
+ (incf *n-bytes-freed-or-purified*
+ (max 0 (- pre-gc-dynamic-usage (dynamic-usage))))
+ (scrub-control-stack)
+ (setf *need-to-collect-garbage* nil)
+ (dolist (h *after-gc-hooks*) (carefully-funcall h))
+ (gc-start-the-world)))))))
;;; This is the user-advertised garbage collection function.
(defun gc (&key (gen 0) (full nil) &allow-other-keys)