Message9941

The thing with PyDequeue makes sense. I actually contradicted my own warnings there and traversed java-objects. I thought I had done it in a safe way, but obviously I was wrong. Try the following fix:

Replace lines 680 onwards of PyDequeue.java with the following code (i.e. such that traverseNode won't be used and replaced by gc.traverseByReflection):


        /* Traverseproc implementation */
        @Override
        public int traverse(Visitproc visit, Object arg) {
            int retVal = super.traverse(visit, arg);
            if (retVal != 0) {
                return retVal;
            }
            //return lastReturned == null ? 0 : traverseNode(lastReturned, visit, arg);
            return lastReturned == null ? 0 :
                    gc.traverseByReflection(lastReturned, visit, arg)
        }

        @Override
        public boolean refersDirectlyTo(PyObject ob) throws UnsupportedOperationException {
            if (ob == null) {
                return false;
            } else if (super.refersDirectlyTo(ob)) {
                return true;
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }


    /* Traverseproc implementation */
//    private static int traverseNode(Node node, Visitproc visit, Object arg) {
//        int retVal;
//        if (node.data != null) {
//            retVal = visit.visit(node.data, arg);
//            if (retVal != 0) {
//                return retVal;
//            }
//        }
//        if (node.left != null) {
//            retVal = traverseNode(node.left, visit, arg);
//            if (retVal != 0) {
//                return retVal;
//            }
//        }
//        return node.right == null ? 0 : traverseNode(node.right, visit, arg);
//    }

    @Override
    public int traverse(Visitproc visit, Object arg) {
        //return header == null ? 0 : traverseNode(header, visit, arg);
        return header == null ? 0 : gc.traverseByReflection(header, visit, arg);
    }

    @Override
    public boolean refersDirectlyTo(PyObject ob) throws UnsupportedOperationException {
        throw new UnsupportedOperationException();
    }
}




--------------

I left removes out-commented so you can better see what was actually changed. gc.traverseByReflection should be safe I suppose. If this cures the bug, we can merge it in, but you must confirm this first, as you are currently the only person able to reproduce this error.