Added an osgDB::ReadWriteMutex to help manage the ability to have serialize

write to objects but allow multiple threads to read at once in a read only way.

src/osgParticle/ParticleProcessor.cpp

@@ -64,13 +64,14 @@ void osgParticle::ParticleProcessor::traverse(osg::NodeVisitor& nv)
         {
             if (nv.getFrameStamp())
             {
-                OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_cullUpdatelMutex);
+                osgDB::ScopedWriteLock lock(_ps->getReadWriteMutex());
 
                 //added- 1/17/06- bgandere@nps.edu 
                 //a check to make sure we havent updated yet this frame
                 if(_frameNumber < nv.getFrameStamp()->getFrameNumber())
                 {
 
+
                     // retrieve the current time
                     double t = nv.getFrameStamp()->getReferenceTime();