From f8fc4f66a8e1829141ed8ded648925f41f60c736 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 22 Jan 2010 20:47:39 +0000
Subject: [PATCH] Added RequestQueue destructor and
 DatabaseRequest::invalidate() and valid() methods to allow the destruction of
 RequestQueue to remove any pointers held in DatabaseRequest attached to the
 scene graph, and to prevent their subsequent use in cases where the scene
 graph is attached to a new DatabasePager.

---
 include/osgDB/DatabasePager | 16 +++++++++++++---
 src/osgDB/DatabasePager.cpp | 30 +++++++++++++++++++++++++++++-
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/include/osgDB/DatabasePager b/include/osgDB/DatabasePager
index d6eb751ad..099de9f0a 100644
--- a/include/osgDB/DatabasePager
+++ b/include/osgDB/DatabasePager
@@ -350,6 +350,7 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         {
             DatabaseRequest():
                 osg::Referenced(true),
+                _valid(false),
                 _frameNumberFirstRequest(0),
                 _timestampFirstRequest(0.0),
                 _priorityFirstRequest(0.f),
@@ -359,7 +360,12 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
                 _numOfRequests(0),
                 _requestQueue(0)
             {}
-            
+
+            void invalidate();
+
+            bool valid() const { return _valid; }
+
+            bool                                _valid;
             std::string                         _fileName;
             int                                 _frameNumberFirstRequest;
             double                              _timestampFirstRequest;
@@ -371,7 +377,7 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
             osg::observer_ptr<osg::Group>       _groupForAddingLoadedSubgraph;
             osg::ref_ptr<osg::Node>             _loadedModel;
             DataToCompileMap                    _dataToCompileMap;
-            osg::ref_ptr<Options> _loadOptions;
+            osg::ref_ptr<Options>               _loadOptions;
             RequestQueue*                       _requestQueue;
 
             bool isRequestCurrent (int frameNumber) const
@@ -382,12 +388,16 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         
         struct RequestQueue : public osg::Referenced
         {
+        public:
             typedef std::vector< osg::ref_ptr<DatabaseRequest> > RequestList;
 
             void sort();
-                                    
+
             RequestList         _requestList;
             OpenThreads::Mutex  _requestMutex;
+
+        protected:
+            virtual ~RequestQueue();
         };
 
         
diff --git a/src/osgDB/DatabasePager.cpp b/src/osgDB/DatabasePager.cpp
index 28da47b74..89362a785 100644
--- a/src/osgDB/DatabasePager.cpp
+++ b/src/osgDB/DatabasePager.cpp
@@ -279,8 +279,30 @@ struct DatabasePager::SortFileRequestFunctor
 
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 //
-//  ReadQueue
+//  RequestQueue
 //
+void DatabasePager::DatabaseRequest::invalidate()
+{
+    osg::notify(osg::INFO)<<"   DatabasePager::DatabaseRequest::invalidate()."<<std::endl;
+    _valid = false;
+    _groupForAddingLoadedSubgraph = 0;
+    _loadedModel = 0;
+    _dataToCompileMap.clear();
+    _requestQueue = 0;
+    _requestQueue = 0;
+}
+
+DatabasePager::RequestQueue::~RequestQueue()
+{
+    osg::notify(osg::INFO)<<"DatabasePager::RequestQueue::~RequestQueue() Destructing queue."<<std::endl;
+    for(RequestList::iterator itr = _requestList.begin();
+        itr != _requestList.end();
+        ++itr)
+    {
+        (*itr)->invalidate();
+    }
+}
+
 void DatabasePager::RequestQueue::sort()
 {
     std::sort(_requestList.begin(),_requestList.end(),SortFileRequestFunctor());
@@ -1295,6 +1317,12 @@ void DatabasePager::requestNodeFile(const std::string& fileName,osg::Group* grou
     if (databaseRequestRef.valid())
     {
         DatabaseRequest* databaseRequest = dynamic_cast<DatabaseRequest*>(databaseRequestRef.get());
+        if (databaseRequest && databaseRequest->valid())
+        {
+            osg::notify(osg::NOTICE)<<"DatabaseRequest has been previously invalidated whilst still attached to scene graph."<<std::endl;
+            databaseRequest = 0;
+        }
+
         if (databaseRequest)
         {
             osg::notify(osg::INFO)<<"DatabasePager::requestNodeFile("<<fileName<<") updating already assigned."<<std::endl;