guile/test-suite/tests/gc.test

;;;; gc.test --- test guile's garbage collection    -*- scheme -*-
;;;; Copyright (C) 2000, 2001, 2004, 2006, 2008 Free Software Foundation, Inc.
;;;;
;;;; This library is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
;;;; version 2.1 of the License, or (at your option) any later version.
;;;; 
;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;;; Lesser General Public License for more details.
;;;; 
;;;; You should have received a copy of the GNU Lesser General Public
;;;; License along with this library; if not, write to the Free Software
;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

(use-modules (ice-9 documentation)
	     (test-suite lib))


;;;
;;; miscellaneous
;;;


(define (documented? object)
  (not (not (object-documentation object))))

;; In guile 1.6.4 this test bombed, due to the record in h being collected
;; by the gc, but not removed from h, leaving "x" as a freed cell.
;; The usual correct result here is for x to be #f, but there's always a
;; chance gc will mark something used when it isn't, so we allow x to be a
;; record too.
(pass-if "weak-values versus records"
  (let ((rec-type (make-record-type "foo" '()))
	(h        (make-weak-value-hash-table 61)))
    (hash-set! h "foo" ((record-constructor rec-type)))
    (gc)
    (let ((x (hash-ref h "foo")))
      (or (not x)
	  ((record-predicate rec-type) x)))))


;;;
;;; 
;;;

(with-test-prefix "gc"

  (pass-if "after-gc-hook gets called"
    (let* ((foo #f)
	   (thunk (lambda () (set! foo #t))))
      (add-hook! after-gc-hook thunk)
      (gc)
      (remove-hook! after-gc-hook thunk)
      foo)))


(with-test-prefix "gc"
  (pass-if "Unused modules are removed"
	   (let*
	       ((dummy (gc))
	        (last-count (cdr (assoc
				  "eval-closure" (gc-live-object-stats)))))

	     (for-each (lambda (x) (make-module)) (iota 1000))

	     ;; XXX: This hack aims to clean up the stack to make sure we
	     ;; don't leave a reference to one of the modules we created.  It
	     ;; proved to be useful on SPARC:
	     ;; http://lists.gnu.org/archive/html/guile-devel/2008-02/msg00006.html .
             (let cleanup ((i 10))
               (and (> i 0)
                    (begin (cleanup (1- i)) i)))

	     (gc)
	     (gc) ;; twice: have to kill the weak vectors.
	     (= last-count (cdr (assoc "eval-closure" (gc-live-object-stats)))))
	   ))