forcing users to use osgDB::readRef*File() methods. The later is preferable as it closes a potential threading bug when using paging databases in conjunction
with the osgDB::Registry Object Cache. This threading bug occurs when one thread gets an object from the Cache via an osgDB::read*File() call where only
a pointer to the object is passed back, so taking a reference to the object is delayed till it gets reassigned to a ref_ptr<>, but at the same time another
thread calls a flush of the Object Cache deleting this object as it's referenceCount is now zero. Using osgDB::readREf*File() makes sure the a ref_ptr<> is
passed back and the referenceCount never goes to zero.
To ensure the OSG builds when OSG_PROVIDE_READFILE is to OFF the many cases of osgDB::read*File() usage had to be replaced with a ref_ptr<> osgDB::readRef*File()
usage. The avoid this change causing lots of other client code to be rewritten to handle the use of ref_ptr<> in place of C pointer I introduced a serious of
templte methods in various class to adapt ref_ptr<> to the underly C pointer to be passed to old OSG API's, example of this is found in include/osg/Group:
bool addChild(Node* child); // old method which can only be used with a Node*
tempalte<class T> bool addChild(const osg::ref_ptr<T>& child) { return addChild(child.get()); } // adapter template method
These changes together cover 149 modified files, so it's a large submission. This extent of changes are warrent to make use of the Object Cache
and multi-threaded loaded more robust.
git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15164 16af8721-9629-0410-8352-f15c8da7e697
Also I've done the osguserstats example. I've kept the "toy example" that was in the modified osgviewer.cpp I had sent you, because they show different uses of custom stats lines (a value displayed directly, a value without bars and a value with bars and graph). I also added a function and a thread that will sleep for a given number of milliseconds and record this time in the stats. I think it clearly shows how to record the time some processing takes and add that to the stats graph, whether the processing takes place on the same thread as the viewer or on another thread.
BTW, feel free to modify the colors I've given to each user stats line... I'm not very artistic. :-)
I've also added more doc comments to the addUserStats() method in ViewerEventHandlers, so hopefully the arguments are clear and the way to get the results you want is also clear. Maybe I went overboard, but the function makes some assumptions that may not be obvious and has many arguments, so I preferred to be explicit."
