Hi Mark, Thanks for uncovering this issue. This is a bug that will need to be fixed, I'm just heading out to a all day meeting so will have to look into it further on my return.
Robert. On Wed, Sep 3, 2008 at 3:01 AM, Mark Sciabica <[EMAIL PROTECTED]> wrote: > Hello Robert (and other list members), > > I have found what may be a bug in multithreaded usage of some objects when > _OSG_REFERENCED_USE_ATOMIC_OPERATIONS is #defined. > > The problem is that osg::Node, osg::Drawable, and osg::StateSet all use the > getRefMutex() method of osg::Referenced to control addition and removal of > obects to their _parents lists. This method always returns null when > _OSG_REFERENCED_USE_ATOMIC_OPERATIONS is #defined. So some code that works > when not using atomic operations may crash when using atomic operations. > > My question is whether it is intended to be safe to add a parent to an > object that is being used in another thread. My first thought was that it > was, otherwise why bother using the mutex when it is available? However, on > further examination, there are other usages of the _parents list that are > unprotected by the mutex, so the intention may have changed since the mutex > protection code was added. > > For context, I ran into this problem creating an osgText::Text object on a > secondary thread and assigning a font to it. Assigning a font entails > setting the font's stateset to the osgText::Text object. Even if I don't > share my fonts between threads, osgText::DefaultFont has a static instance > that is used by all osgText::Text objects that haven't had their fonts set > and would cause similar problems. > > So my workaround for now is to change my build settings so that the mutex is > used instead of the atomic operations. Or perhaps I should abandon this line > of coding and the above mentioned mutex use should be deleted from osg. > > > Regards, > > Mark > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
