X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=BUGS;h=bc78b722fffb9d57207276826cde5f9bdb5868ce;hb=471a5d32673a4c0db86949424d624e6ea3a6a633;hp=ac698a4c37b6f378d605f48d5a53be7f8c4b8232;hpb=2fb5b174f6acb88a85c86aa4cd753ddefaccc987;p=sbcl.git

diff --git a/BUGS b/BUGS
index ac698a4..bc78b72 100644
--- a/BUGS
+++ b/BUGS
@@ -2100,3 +2100,53 @@ WORKAROUND:
      instead errors.
 
      (reported on sbcl-help by "tichy")
+
+396: block-compilation bug
+    (let ((x 1))
+      (dotimes (y 10)
+        (let ((y y))
+          (when (funcall (eval #'(lambda (x) (eql x 2))) y)
+            (defun foo (z)
+              (incf x (incf y z))))))
+      (defun bar (z)
+        (foo z)
+        (values x)))
+  (bar 1) => 11, should be 4.
+
+397: SLEEP accuracy
+  The more interrupts arrive the less accurate SLEEP's timing gets.
+    (time (sb-thread:terminate-thread
+            (prog1 (sb-thread:make-thread (lambda ()
+                                            (loop
+                                             (princ #\!)
+                                             (force-output)
+                                             (sb-ext:gc))))
+              (sleep 1))))
+
+398: GC-unsafe SB-ALIEN string deporting
+  Translating a Lisp string to an alien string by taking a SAP to it
+  as done by the :DEPORT-GEN methods for C-STRING and UTF8-STRING
+  is not safe, since the Lisp string can move. For example the
+  following code will fail quickly on both cheneygc and pre-0.9.8.19
+  GENCGC: 
+
+  (setf (bytes-consed-between-gcs) 4096)
+  (define-alien-routine "strcmp" int (s1 c-string) (s2 c-string))
+     
+  (loop
+    (let ((string "hello, world"))
+       (assert (zerop (strcmp string string)))))
+     
+  (This will appear to work on post-0.9.8.19 GENCGC, since
+   the GC no longer zeroes memory immediately after releasing
+   it after a minor GC. Either enabling the READ_PROTECT_FREE_PAGES
+   #define in gencgc.c or modifying the example so that a major
+   GC will occasionally be triggered would unmask the bug.)
+
+  On cheneygc the only solution would seem to be allocating some alien
+  memory, copying the data over, and arranging that it's freed once we
+  return. For GENCGC we could instead try to arrange that the string
+  from which the SAP is taken is always pinned.
+
+  For some more details see comments for (define-alien-type-method
+  (c-string :deport-gen) ...)  in host-c-call.lisp.