Hi Robert, I am using osg 2.6.0 and you're right, osg::Node as well as osg::Stateset use getRefMutex for protecting the access to the parent list. However getRefMutex isn't used in the atomic refcounted case and osg::StateAttribute doesn't use a mutex at all for protecting the parents.
The method (Node|Stateset|StateAttribute) ::getParent, ::getParents, ::getNumParents doesn't seem to be protected by a mutex as well. I wonder if that's intented. Richard >HI Richard, > >Which version of the OSG are you using? The OSG has had mutex >protection of addParents/removeParent() for quite some while. > >Robert. On Mon, Oct 13, 2008 at 7:59 AM, Schmidt, Richard <[EMAIL PROTECTED]> wrote: > Osg has the option to cache nodes by using osgDB:Registry. Retrieving a node > from the cache and attaching them to your subgraph is not threadsafe, > because Node::addParent, Node::removeParent and Node::getParents is not > threadsafe. > > > > Consider this scenario: A node gets 'disposed' in the main thread, because > the 'user' deatches the node from the graph. At the same time the node may > be loaded from the cache by the databasepager. While the refcounting will > work perfectly, the calls to Node::addParent and Node::removeParent is not > threadsafe, causing the node to get an invalid parent setup. > > > > The same holds for StateSet and StateAttribute (because they have > parentlinks as well). Example: The openflight loader stores static ref > pointers to various StateAttributes. The StateAttribute::addParent and > StateAttribute::removeParent may be called from multiple threads, i.e the > main thread releases a model, while another thread (the databasepager) loads > the model. > > > > Possible solution: Make the parent links threadsafe. For Statesets and > StateAttributes I would remove them and implementing an "immutable" pattern > instead. > > > > Richard > > > > Richard Schmidt > > System Designer > > EADS Deutschland GmbH > > Organisationseinheit (SDGE1) > > > > EADS Deutschland GmbH > > Registered Office: Ottobrunn > > District Court of Munich HRB107648 > > Chairman of the Supervisory Board: Dr. Thomas Enders Managing Directors: Dr. > Stefan Zoller (chairman), Michael Hecht > > This E-mail And any attachment(s) to it are for the addressee's use only. It > is strictly confidential and may contain legally privileged information. No > confidentiality Or privilege is waived or lost by any mistransmission. If > you are not the intended addressee, then please delete it from your system > and notify the sender immediately. You are hereby notified that any use, > disclosure, copying or any action taken in reliance on it is strictly > prohibited and may be unlawful. - Thank you. > > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g > > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
