[linear] Simplify initialization of parallel helper

dumux/linear/amgbackend.hh

@@ -60,8 +60,6 @@ public:
     {
         if (isParallel_)
             DUNE_THROW(Dune::InvalidStateException, "Using sequential constructor for parallel run. Use signature with gridView and dofMapper!");
-
-        reset();
     }
 
     /*!
@@ -76,11 +74,13 @@ public:
                        const std::string& paramGroup = "")
     : LinearSolver(paramGroup)
 #if HAVE_MPI
-    , phelper_(std::make_unique<ParallelISTLHelper<LinearSolverTraits>>(gridView, dofMapper))
     , isParallel_(Dune::MPIHelper::getCollectiveCommunication().size() > 1)
 #endif
     {
-        reset();
+#if HAVE_MPI
+        if (isParallel_)
+            phelper_ = std::make_unique<ParallelISTLHelper<LinearSolverTraits>>(gridView, dofMapper);
+#endif
     }
 
     /*!
@@ -98,16 +98,9 @@ public:
 #else
         solveSequential_(A, x, b);
 #endif
-        firstCall_ = false;
         return result_.converged;
     }
 
-    //! reset the linear solver
-    void reset()
-    {
-        firstCall_ = true;
-    }
-
     /*!
      * \brief The name of the solver
      */
@@ -161,9 +154,6 @@ private:
         using LinearOperator = typename ParallelTraits::LinearOperator;
         using ScalarProduct = typename ParallelTraits::ScalarProduct;
 
-        if (firstCall_)
-            phelper_->initGhostsAndOwners();
-
         std::shared_ptr<Comm> comm;
         std::shared_ptr<LinearOperator> linearOperator;
         std::shared_ptr<ScalarProduct> scalarProduct;
@@ -224,7 +214,6 @@ private:
 #endif
     Dune::InverseOperatorResult result_;
     bool isParallel_ = false;
-    bool firstCall_;
 };
 
 } // end namespace Dumux

dumux/linear/istlsolverfactorybackend.hh

@@ -131,7 +131,8 @@ public:
         if (isParallel_)
             DUNE_THROW(Dune::InvalidStateException, "Using sequential constructor for parallel run. Use signature with gridView and dofMapper!");
 
-        reset();
+        firstCall_ = true;
+        initializeParameters_();
     }
 
     /*!
@@ -146,11 +147,15 @@ public:
                              const std::string& paramGroup = "")
     : paramGroup_(paramGroup)
 #if HAVE_MPI
-    , parallelHelper_(std::make_unique<ParallelISTLHelper<LinearSolverTraits>>(gridView, dofMapper))
     , isParallel_(Dune::MPIHelper::getCollectiveCommunication().size() > 1)
 #endif
     {
-        reset();
+        firstCall_ = true;
+        initializeParameters_();
+#if HAVE_MPI
+        if (isParallel_)
+            parallelHelper_ = std::make_unique<ParallelISTLHelper<LinearSolverTraits>>(gridView, dofMapper);
+#endif
     }
 
     /*!
@@ -172,17 +177,6 @@ public:
         return result_.converged;
     }
 
-    //! reset the linear solver factory
-    void reset()
-    {
-        firstCall_ = true;
-        params_ = LinearSolverParameters<LinearSolverTraits>::createParameterTree(paramGroup_);
-        checkMandatoryParameters_();
-        name_ = params_.get<std::string>("preconditioner.type") + "-preconditioned " + params_.get<std::string>("type");
-        if (params_.get<int>("verbose", 0) > 0)
-            std::cout << "Initialized linear solver of type: " << name_ << std::endl;
-    }
-
     const Dune::InverseOperatorResult& result() const
     {
         return result_;
@@ -195,6 +189,15 @@ public:
 
 private:
 
+    void initializeParameters_()
+    {
+        params_ = LinearSolverParameters<LinearSolverTraits>::createParameterTree(paramGroup_);
+        checkMandatoryParameters_();
+        name_ = params_.get<std::string>("preconditioner.type") + "-preconditioned " + params_.get<std::string>("type");
+        if (params_.get<int>("verbose", 0) > 0)
+            std::cout << "Initialized linear solver of type: " << name_ << std::endl;
+    }
+
     void checkMandatoryParameters_()
     {
         if (!params_.hasKey("type"))
@@ -244,10 +247,7 @@ private:
         using ScalarProduct = typename ParallelTraits::ScalarProduct;
 
         if (firstCall_)
-        {
             initSolverFactories<Matrix, LinearOperator>();
-            parallelHelper_->initGhostsAndOwners();
-        }
 
         std::shared_ptr<Comm> comm;
         std::shared_ptr<LinearOperator> linearOperator;

dumux/linear/parallelhelpers.hh

@@ -276,15 +276,17 @@ class ParallelISTLHelper
 public:
 
     ParallelISTLHelper(const GridView& gridView, const DofMapper& mapper)
-        : gridView_(gridView), mapper_(mapper), initialized_(false)
-    {}
+    : gridView_(gridView), mapper_(mapper)
+    {
+        initGhostsAndOwners();
+    }
 
     // \brief Initializes the markers for ghosts and owners with the correct size and values.
     //
     void initGhostsAndOwners()
     {
         const auto rank = gridView_.comm().rank();
-        isOwned_.resize(mapper_.size(), rank);
+        isOwned_.assign(mapper_.size(), rank);
         // find out about ghosts
         GhostGatherScatter ggs(isOwned_, mapper_);
 
@@ -302,8 +304,6 @@ public:
         // convert vector into mask vector
         for (auto& v : isOwned_)
             v = (v == rank) ? 1 : 0;
-
-        initialized_ = true;
     }
 
     bool isGhost(std::size_t i) const
@@ -316,16 +316,8 @@ public:
      * communicators.
      */
     template<class Comm>
-    void createParallelIndexSet(Comm& comm)
+    void createParallelIndexSet(Comm& comm) const
     {
-        if (!initialized_)
-        {
-            // This is the first time this function is called.
-            // Therefore we need to initialize the marker vectors for ghosts and
-            // owned dofs
-            initGhostsAndOwners();
-        }
-
         if (gridView_.comm().size() <= 1)
         {
             comm.remoteIndices().template rebuild<false>();
@@ -423,7 +415,6 @@ private:
     const DofMapper& mapper_; //!< the dof mapper
     std::vector<std::size_t> isOwned_; //!< vector to identify unique decomposition
     std::vector<std::size_t> isGhost_; //!< vector to identify ghost dofs
-    bool initialized_; //!< whether isGhost and owner arrays are initialized
 
 }; // class ParallelISTLHelper