Added re-entrent mutex to serialize access to OpenFlight plugin to prevent

any multi-threaded issues.

src/osgPlugins/flt/ReaderWriterFLT.cpp

@@ -25,6 +25,9 @@ osgDB::ReaderWriter::ReadResult ReaderWriterFLT::readObject(const std::string& f
 
 osgDB::ReaderWriter::ReadResult ReaderWriterFLT::readNode(const std::string& file, const osgDB::ReaderWriter::Options* options) const
 {
+    // serialize all access to the OpenFlight plugin as its not thread safe by itself.
+    OpenThreads::ScopedLock<osgDB::ReentrantMutex> lock(_serializerMutex);
+
     std::string ext = osgDB::getLowerCaseFileExtension(file);
     if (!acceptsExtension(ext)) return ReadResult::FILE_NOT_HANDLED;
 

src/osgPlugins/flt/ReaderWriterFLT.h

@@ -1,4 +1,3 @@
-
 //
 // OpenFlight<68> loader for Open Scene Graph
 //
@@ -39,6 +38,7 @@
 
 #include <osgDB/Registry>
 #include <osgDB/FileNameUtils>
+#include <osgDB/ReentrantMutex>
 
 
 namespace flt {
@@ -56,6 +56,10 @@ public:
 
     virtual ReadResult readObject(const std::string& fileName, const osgDB::ReaderWriter::Options*) const;
     virtual ReadResult readNode(const std::string& fileName, const osgDB::ReaderWriter::Options*) const;
+
+protected:
+
+    mutable osgDB::ReentrantMutex _serializerMutex;
 };