Merge pull request #6870 from bangerth/observer-pointer

Let SimulatorAccess store an observer pointer to Simulator.

Author: gassmoeller

include/aspect/compat.h

@@ -64,6 +64,22 @@ namespace aspect
 #endif
 
 
+#if !DEAL_II_VERSION_GTE(9,7,0)
+  /**
+   * A type alias for the SmartPointer class that makes sure the new
+   * name of the class, ObserverPointer, can be used in all versions of
+   * deal.II. The SmartPointer class was renamed to ObserverPointer in
+   * deal.II 9.7.
+   */
+  template <typename T, typename P = void>
+  using ObserverPointer = dealii::SmartPointer<T, P>;
+
+  /**
+   * Same for the transition from Subscriptor to EnableObserverPointer.
+   */
+  using EnableObserverPointer = dealii::Subscriptor;
+#endif
+
 
 // deal.II versions up to 9.5 had a poorly designed interface of the
 // SphericalManifold class that made it impossible for us to use.

include/aspect/simulator.h

@@ -197,7 +197,7 @@ namespace aspect
    * @ingroup Simulator
    */
   template <int dim>
-  class Simulator
+  class Simulator : public EnableObserverPointer
   {
     public:
       /**

include/aspect/simulator_access.h

@@ -223,7 +223,7 @@ namespace aspect
        * Destructor. Does nothing but is virtual so that derived classes
        * destructors are also virtual.
        */
-      virtual ~SimulatorAccess () = default;
+      virtual ~SimulatorAccess ();
 
       /**
        * Initialize this class for a given simulator. This function is marked
@@ -1081,7 +1081,7 @@ namespace aspect
       /**
        * A pointer to the simulator object to which we want to get access.
        */
-      const Simulator<dim> *simulator;
+      ObserverPointer<const Simulator<dim>, SimulatorAccess<dim>> simulator;
   };
 }
 

source/particle/property/cpo_bingham_average.cc

@@ -22,6 +22,7 @@
 #include <aspect/particle/manager.h>
 
 #include <aspect/utilities.h>
+#include <aspect/simulator.h>
 
 namespace aspect
 {

source/simulator/simulator_access.cc

@@ -49,6 +49,15 @@ namespace aspect
 
 
 
+  // Define the destructor as defaulted. One might have wanted to do that in
+  // the header file, but that requires all member variables to be complete
+  // types (in particular, the Simulator class), which is not the casein the
+  // .h file.
+  template <int dim>
+  SimulatorAccess<dim>::~SimulatorAccess () = default;
+
+
+
   template <int dim>
   void
   SimulatorAccess<dim>::initialize_simulator (const Simulator<dim> &simulator_object)

unit_tests/particles.cc

@@ -21,12 +21,39 @@
 #include "common.h"
 #include <aspect/particle/property/interface.h>
 #include <aspect/particle/manager.h>
+#include <aspect/simulator.h>
 #include <deal.II/base/parameter_handler.h>
 
 TEST_CASE("Particle Manager plugin names")
 {
+  // The Particle::Property::Manager needs to know about the Simulator object,
+  // so we need to create a dummy one to initialize the manager. That, in
+  // turn, needs to be initialized with a ParameterHandler, so we create one
+  // and fill it with the minimum information needed to create a Simulator object.
+  aspect::ParameterHandler sim_prm;
+  aspect::Simulator<2>::declare_parameters(sim_prm, 0);
+  {
+    sim_prm.enter_subsection("Geometry model");
+    sim_prm.set("Model name", "box");
+    sim_prm.leave_subsection();
+  }
+  {
+    sim_prm.enter_subsection("Material model");
+    sim_prm.set("Model name", "simple");
+    sim_prm.leave_subsection();
+  }
+  {
+    sim_prm.enter_subsection("Gravity model");
+    sim_prm.set("Model name", "vertical");
+    sim_prm.leave_subsection();
+  }
+  aspect::Simulator<2> dummy_sim (MPI_COMM_SELF, sim_prm);
+
+  // Now create a Particle::Property::Manager and initialize it with the dummy simulator.
   dealii::ParameterHandler prm;
   aspect::Particle::Property::Manager<2> manager;
+  manager.initialize_simulator (dummy_sim);
+
   // The property manager needs to know about the integrator, which is declared in World
   aspect::Particle::Manager<2>::declare_parameters(prm);