Modified setup to provide default getter

Use getter/setter to supply the required properties for the new reuse
capability.  Default to libmesh_not_implemented() in superclass,
implemented in the petsc solvers.

include/solvers/nonlinear_solver.h

@@ -350,21 +350,42 @@ class NonlinearSolver : public ReferenceCountedObject<NonlinearSolver<T>>,
   bool converged;
 
   /**
-   * Whether we should reuse the linear preconditioner
+   * Set the solver configuration object.
    */
-  bool reuse_preconditioner;
+  void set_solver_configuration(SolverConfiguration & solver_configuration);
 
   /**
-   * Number of linear iterations to retain the preconditioner
+   *  Get the reuse_preconditioner flag
    */
-  unsigned int reuse_preconditioner_max_its;
+  virtual bool reuse_preconditioner() const;
 
   /**
-   * Set the solver configuration object.
+   *  Set the reuse preconditioner flag
    */
-  void set_solver_configuration(SolverConfiguration & solver_configuration);
+  virtual void set_reuse_preconditioner(bool reuse);
+
+  /**
+   *  Get the reuse_preconditioner_max_its parameter
+   */
+  virtual unsigned int reuse_preconditioner_max_its() const;
+
+  /**
+   *  Set the reuse_preconditioner_max_its parameter
+   */
+  virtual void set_reuse_preconditioner_max_its(unsigned int i);
+
 
 protected:
+  /**
+   * Whether we should reuse the linear preconditioner
+   */
+  bool _reuse_preconditioner;
+
+  /**
+   * Number of linear iterations to retain the preconditioner
+   */
+  unsigned int _reuse_preconditioner_max_its;
+
   /**
    * A reference to the system we are solving.
    */
@@ -425,8 +446,8 @@ NonlinearSolver<T>::NonlinearSolver (sys_type & s) :
   initial_linear_tolerance(0),
   minimum_linear_tolerance(0),
   converged(false),
-  reuse_preconditioner(false),
-  reuse_preconditioner_max_its(0),
+  _reuse_preconditioner(false),
+  _reuse_preconditioner_max_its(0),
   _system(s),
   _is_initialized (false),
   _preconditioner (nullptr),

include/solvers/petsc_nonlinear_solver.h

@@ -207,6 +207,16 @@ class PetscNonlinearSolver : public NonlinearSolver<T>
     */
   void setup_default_monitor();
 
+  /**
+   * Getter for preconditioner reuse
+   */
+  virtual bool reuse_preconditioner() const;
+
+  /**
+   *  Getter for the maximum iterations flag for preconditioner reuse
+   */
+  virtual unsigned int reuse_preconditioner_max_its() const;
+
 protected:
 
   /**

src/solvers/nonlinear_solver.C

@@ -84,6 +84,29 @@ void NonlinearSolver<T>::set_solver_configuration(SolverConfiguration & solver_c
   _solver_configuration = &solver_configuration;
 }
 
+template <typename T>
+bool NonlinearSolver<T>::reuse_preconditioner() const
+{
+  libmesh_not_implemented();
+}
+
+template <typename T>
+void NonlinearSolver<T>::set_reuse_preconditioner(bool reuse)
+{
+  _reuse_preconditioner = reuse;
+}
+
+template <typename T>
+unsigned int NonlinearSolver<T>::reuse_preconditioner_max_its() const
+{
+  libmesh_not_implemented();
+}
+
+template <typename T>
+void NonlinearSolver<T>::set_reuse_preconditioner_max_its(unsigned int i)
+{
+  _reuse_preconditioner_max_its = i;
+}
 
 //------------------------------------------------------------------
 // Explicit instantiations

src/solvers/petsc_nonlinear_solver.C

@@ -670,7 +670,7 @@ void PetscNonlinearSolver<T>::clear ()
       // If we don't need the preconditioner next time
       // retain the original behavior of clearing the data
       // between solves.
-      if (!(this->reuse_preconditioner))
+      if (!(reuse_preconditioner()))
         {
         // SNESReset really ought to work but replacing destory() with
         // SNESReset causes a very slight change in behavior that
@@ -871,7 +871,7 @@ PetscNonlinearSolver<T>::solve (SparseMatrix<T> &  pre_in,  // System Preconditi
 
   // We don't want to do this twice because it resets
   // SNESSetLagPreconditioner
-  if ((this->reuse_preconditioner) && (!_setup_reuse))
+  if ((reuse_preconditioner()) && (!_setup_reuse))
     {
       _setup_reuse = true;
       ierr = SNESSetLagPreconditionerPersists(_snes, PETSC_TRUE);
@@ -882,13 +882,14 @@ PetscNonlinearSolver<T>::solve (SparseMatrix<T> &  pre_in,  // System Preconditi
       LIBMESH_CHKERR(ierr);
       // Add in our callback which will trigger recalculating
       // the preconditioner when we hit reuse_preconditioner_max_its
+      unsigned int max_its = reuse_preconditioner_max_its();
       ierr = SNESMonitorSet(_snes, &libmesh_petsc_recalculate_monitor,
                             (void*)
-                            &(this->reuse_preconditioner_max_its),
+                            &max_its,
                             NULL);
       LIBMESH_CHKERR(ierr);
     }
-  else if (!(this->reuse_preconditioner))
+  else if (!(reuse_preconditioner()))
     // This covers the case where it was enabled but was then disabled
     {
       ierr = SNESSetLagPreconditionerPersists(_snes, PETSC_FALSE);
@@ -1126,6 +1127,18 @@ void PetscNonlinearSolver<T>::setup_default_monitor()
     }
 }
 
+template <typename T>
+bool PetscNonlinearSolver<T>::reuse_preconditioner() const
+{
+  return this->_reuse_preconditioner;
+}
+
+template <typename T>
+unsigned int PetscNonlinearSolver<T>::reuse_preconditioner_max_its() const
+{
+  return this->_reuse_preconditioner_max_its;
+}
+
 
 //------------------------------------------------------------------
 // Explicit instantiations

src/systems/nonlinear_implicit_system.C

@@ -148,8 +148,8 @@ void NonlinearImplicitSystem::set_solver_parameters ()
   nonlinear_solver->max_linear_iterations = maxlinearits;
   nonlinear_solver->initial_linear_tolerance = linear_tol;
   nonlinear_solver->minimum_linear_tolerance = linear_min_tol;
-  nonlinear_solver->reuse_preconditioner =  reuse_preconditioner;
-  nonlinear_solver->reuse_preconditioner_max_its = reuse_preconditioner_max_its;
+  nonlinear_solver->set_reuse_preconditioner(reuse_preconditioner);
+  nonlinear_solver->set_reuse_preconditioner_max_its(reuse_preconditioner_max_its);
 
   if (diff_solver.get())
     {