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//

//   Create, recycle and Workspaces
//  Only one object of this type exists - it is a true Singleton (not per thread).

#ifndef G4GEOMETRYWORKSPACEPOOL_HH
#define G4GEOMETRYWORKSPACEPOOL_HH

class G4GeometryWorkspace;
// #include "G4GeometryWorkspace.hh"

//Note: Investigate potential to make it a template - on the workspace type

class G4GeometryWorkspacePool
{
  public: 
     static G4GeometryWorkspacePool* GetInstance();

   // For use with simple MT mode - each thread gets a workspace and uses it until end
     G4GeometryWorkspace* CreateWorkspace();

     void CreateAndUseWorkspace();  // Create it (as above) and use it
  
   // For use with 'dynamic' model of threading - workspaces can be recycled
     G4GeometryWorkspace* FindOrCreateWorkspace();
      // Reuse an existing workspace - or create a new one if needed.
      // This will never fail, except if system is out of resources

     inline G4GeometryWorkspace* GetWorkspace() { return fMyWorkspace; } 
      // Give back the existing, active workspace for my thread / task

     void Recycle( G4GeometryWorkspace * );
      // Keep the unused Workspace - for recycling

     void CleanUpAndDestroyAllWorkspaces();
     // To be called once at the end of the job
  
 protected:
      void ReleaseAndDestroyWorkspace(G4GeometryWorkspace*);
      // Destroy workspace - after releasing it

      // void RegisterWarehouse( G4GeometryWarehouse *) ;
      // The (optional) warehouse keeps a list of free workspaces

 private:
      G4GeometryWorkspacePool();
     ~G4GeometryWorkspacePool();

 private: 
     static G4GeometryWorkspacePool* thePool;

     //void* fWarehouse;
     // G4GeometryWarehouse* fWarehouse;
     // This is "void" to hide the actual container type for workspaces
     // Implementations: a simple STL contaier for MT or something better for tbb
     // Further development: template parameter with portable default

     static G4ThreadLocal G4GeometryWorkspace*    fMyWorkspace;
     // The thread's workspace - if assigned.
     //  --> Can we do without this ?  It is dirty!!
};

#endif //G4GEOMETRYWORKSPACEPOOL_HH