Merge branch 'feature/linear-solver-parallel-firstcall' into 'master'

Feature/linear solver parallel firstcall

See merge request !1867

dumux/linear/amgbackend.hh

@@ -64,10 +64,11 @@ public:
     AMGBiCGSTABBackend(const std::string& paramGroup = "")
     : LinearSolver(paramGroup)
     , isParallel_(Dune::MPIHelper::getCollectiveCommunication().size() > 1)
-    , firstCall_(true)
     {
         if (isParallel_)
             DUNE_THROW(Dune::InvalidStateException, "Using sequential constructor for parallel run. Use signature with gridView and dofMapper!");
+
+        reset();
     }
 
     /*!
@@ -83,8 +84,9 @@ public:
     : LinearSolver(paramGroup)
     , phelper_(std::make_shared<ParallelISTLHelper<LinearSolverTraits>>(gridView, dofMapper))
     , isParallel_(Dune::MPIHelper::getCollectiveCommunication().size() > 1)
-    , firstCall_(true)
-    {}
+    {
+        reset();
+    }
 
     /*!
      * \brief Solve a linear system.
@@ -105,6 +107,12 @@ public:
         return result_.converged;
     }
 
+    //! reset the linear solver
+    void reset()
+    {
+        firstCall_ = true;
+    }
+
     /*!
      * \brief The name of the solver
      */
@@ -158,10 +166,13 @@ 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;
-        prepareLinearAlgebraParallel<LinearSolverTraits, ParallelTraits>(A, b, comm, linearOperator, scalarProduct, *phelper_, firstCall_);
+        prepareLinearAlgebraParallel<LinearSolverTraits, ParallelTraits>(A, b, comm, linearOperator, scalarProduct, *phelper_);
 
         using SeqSmoother = Dune::SeqSSOR<Matrix, Vector, Vector>;
         using Smoother = typename ParallelTraits::template Preconditioner<SeqSmoother>;

dumux/linear/parallelhelpers.hh

@@ -792,11 +792,8 @@ void prepareLinearAlgebraParallel(Matrix& A, Vector& b,
                                   std::shared_ptr<typename ParallelTraits::Comm>& comm,
                                   std::shared_ptr<typename ParallelTraits::LinearOperator>& fop,
                                   std::shared_ptr<typename ParallelTraits::ScalarProduct>& sp,
-                                  ParallelHelper& pHelper,
-                                  const bool firstCall)
+                                  ParallelHelper& pHelper)
 {
-    if (firstCall) pHelper.initGhostsAndOwners();
-
     if constexpr (ParallelTraits::isNonOverlapping)
     {
         // extend the matrix pattern such that it is usable for a parallel solver