Hi Ryan, On Tue, Jun 16, 2009 at 5:30 PM, Kawicki, Ryan H<[email protected]> wrote: > Robert, > > I want to take us back to a bug that was found in Sep. of 2008. > > http://www.mail-archive.com/[email protected]/msg15483. > html
The issue brought up in the original thread has been already been addressed in recent OSG versions, so the getRefMutex no longer returns NULL, but returns the shared global mutex. So I don't believe this is an issue any more. > > I do agree that there was an issue at this point not having some kind of > locking system in place when accessing the parents, but is a global > mutex the right answer when _OSG_REFERENCED_USE_ATOMIC_OPERATIONS is > defined. If two unrelated group nodes on different threads add > unrelated children, there is the possibility that one will block the > other. A perfect example of this is the main thread and a database > pager. I'm not clear on how this example would cause a problem with a single mutex lock being used in this context. Do you have an actual crash/error in behavior that you have observed? > As stated by the previous thread, this is not only related to group > nodes. Drawables, Nodes, StateAttributes, and StateSets also use the > global mutex. Was there a reason for using a global mutex instead of a > mutex owned by an instance of osg::Referenced? Speed of creation and deletion objects and memory consumption is the reason not to have a Mutex per Referenced object. Mutex's are relatively large and slow to create/destroy which is amoung the reasons why using atomic ref counts where possible is desirable. Robert. _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
