MLMG interface (AMReX-Codes#2858)

These changes are made to support a generic type (i.e., amrex::Any) in MLMG.
This is still work in progress.  But it should not break any existing codes.

Author: WeiqunZhang

Src/Base/AMReX_Any.H

@@ -60,15 +60,18 @@ public:
 private:
     struct innards_base {
         virtual const std::type_info& Type () const = 0;
+        virtual ~innards_base () = default;
     };
 
     template <typename MF>
     struct innards : innards_base
     {
-        innards(MF && mf)
+        innards (MF && mf)
             : m_mf(std::forward<MF>(mf))
             {}
 
+        virtual ~innards () = default;
+
         virtual const std::type_info& Type () const override {
             return typeid(MF);
         }

Src/Base/AMReX_BaseFab.H

@@ -260,7 +260,7 @@ public:
      */
     void clear () noexcept;
 
-    // Release ownership of memory
+    //! Release ownership of memory
     std::unique_ptr<T,DataDeleter> release () noexcept;
 
     //! Returns how many bytes used

Src/Base/AMReX_FabArray.H

@@ -2848,7 +2848,7 @@ FabArray<FAB>::SumBoundary_nowait (int scomp, int ncomp, IntVect const& src_ngho
 
     FabArray<FAB>* tmp = new FabArray<FAB>( boxArray(), DistributionMap(), ncomp, src_nghost, MFInfo(), Factory() );
     amrex::Copy(*tmp, *this, scomp, 0, ncomp, src_nghost);
-    this->setVal(0.0, scomp, ncomp, dst_nghost);
+    this->setVal(typename FAB::value_type(0), scomp, ncomp, dst_nghost);
     this->ParallelCopy_nowait(*tmp,0,scomp,ncomp,src_nghost,dst_nghost,period,FabArrayBase::ADD);
 
     // All local. Operation complete.

Src/LinearSolvers/MLMG/AMReX_MLABecLaplacian.cpp

@@ -323,10 +323,10 @@ MLABecLaplacian::applyMetricTermsCoeffs ()
     for (int alev = 0; alev < m_num_amr_levels; ++alev)
     {
         const int mglev = 0;
-        applyMetricTerm(alev, mglev, m_a_coeffs[alev][mglev]);
+        applyMetricTermToMF(alev, mglev, m_a_coeffs[alev][mglev]);
         for (int idim = 0; idim < AMREX_SPACEDIM; ++idim)
         {
-            applyMetricTerm(alev, mglev, m_b_coeffs[alev][mglev][idim]);
+            applyMetricTermToMF(alev, mglev, m_b_coeffs[alev][mglev][idim]);
         }
     }
 #endif

Src/LinearSolvers/MLMG/AMReX_MLCGSolver.H

@@ -40,6 +40,11 @@ public:
                Real            eps_rel,
                Real            eps_abs);
 
+    int solve (Any&       solnL,
+               const Any& rhsL,
+               Real       eps_rel,
+               Real       eps_abs);
+
     void setVerbose (int _verbose) { verbose = _verbose; }
     int getVerbose () const { return verbose; }
 

Src/LinearSolvers/MLMG/AMReX_MLCGSolver.cpp

@@ -78,6 +78,13 @@ MLCGSolver::solve (MultiFab&       sol,
     }
 }
 
+int
+MLCGSolver::solve (Any& sol, const Any& rhs, Real eps_rel, Real eps_abs)
+{
+    AMREX_ASSERT(sol.is<MultiFab>()); // xxxxx TODO: MLCGSolver Any
+    return solve(sol.get<MultiFab>(), rhs.get<MultiFab>(), eps_rel, eps_abs);
+}
+
 int
 MLCGSolver::solve_bicgstab (MultiFab&       sol,
                             const MultiFab& rhs,

Src/LinearSolvers/MLMG/AMReX_MLCellABecLap.H

@@ -59,9 +59,9 @@ public:
     virtual MultiFab const* getACoeffs (int amrlev, int mglev) const = 0;
     virtual Array<MultiFab const*,AMREX_SPACEDIM> getBCoeffs (int amrlev, int mglev) const = 0;
 
-    virtual void applyInhomogNeumannTerm (int amrlev, MultiFab& rhs) const final override;
+    virtual void applyInhomogNeumannTerm (int amrlev, Any& rhs) const final override;
 
-    virtual void applyOverset (int amlev, MultiFab& rhs) const override;
+    virtual void applyOverset (int amlev, Any& rhs) const override;
 
 #if defined(AMREX_USE_HYPRE) && (AMREX_SPACEDIM > 1)
     virtual std::unique_ptr<Hypre> makeHypre (Hypre::Interface hypre_interface) const override;

Src/LinearSolvers/MLMG/AMReX_MLCellABecLap.cpp

@@ -108,7 +108,7 @@ MLCellABecLap::define (const Vector<Geometry>& a_geom,
     amrlev = 0;
     for (int mglev = 1; mglev < m_num_mg_levels[amrlev]; ++mglev) {
         MultiFab foo(m_grids[amrlev][mglev], m_dmap[amrlev][mglev], 1, 0, MFInfo().SetAlloc(false));
-        if (! isMFIterSafe(*m_overset_mask[amrlev][mglev], foo)) {
+        if (! amrex::isMFIterSafe(*m_overset_mask[amrlev][mglev], foo)) {
             auto osm = std::make_unique<iMultiFab>(m_grids[amrlev][mglev],
                                                    m_dmap[amrlev][mglev], 1, 1);
             osm->ParallelCopy(*m_overset_mask[amrlev][mglev]);
@@ -193,13 +193,16 @@ MLCellABecLap::getFluxes (const Vector<Array<MultiFab*,AMREX_SPACEDIM> >& a_flux
 }
 
 void
-MLCellABecLap::applyInhomogNeumannTerm (int amrlev, MultiFab& rhs) const
+MLCellABecLap::applyInhomogNeumannTerm (int amrlev, Any& a_rhs) const
 {
     bool has_inhomog_neumann = hasInhomogNeumannBC();
     bool has_robin = hasRobinBC();
 
     if (!has_inhomog_neumann && !has_robin) return;
 
+    AMREX_ASSERT(a_rhs.is<MultiFab>());
+    MultiFab& rhs = a_rhs.get<MultiFab>();
+
     int ncomp = getNComp();
     const int mglev = 0;
 
@@ -414,9 +417,11 @@ MLCellABecLap::applyInhomogNeumannTerm (int amrlev, MultiFab& rhs) const
 }
 
 void
-MLCellABecLap::applyOverset (int amrlev, MultiFab& rhs) const
+MLCellABecLap::applyOverset (int amrlev, Any& a_rhs) const
 {
     if (m_overset_mask[amrlev][0]) {
+        AMREX_ASSERT(a_rhs.is<MultiFab>());
+        auto& rhs = a_rhs.get<MultiFab>();
         const int ncomp = getNComp();
 #ifdef AMREX_USE_OMP
 #pragma omp parallel if (Gpu::notInLaunchRegion())

Src/LinearSolvers/MLMG/AMReX_MLCellLinOp.H

@@ -3,6 +3,7 @@
 #include <AMReX_Config.H>
 
 #include <AMReX_MLLinOp.H>
+#include <AMReX_iMultiFab.H>
 
 namespace amrex {
 
@@ -109,6 +110,8 @@ public:
 
     virtual void interpolation (int amrlev, int fmglev, MultiFab& fine, const MultiFab& crse) const override;
 
+    virtual void interpAssign (int amrlev, int fmglev, MultiFab& fine, MultiFab& crse) const override;
+
     virtual void averageDownSolutionRHS (int camrlev, MultiFab& crse_sol, MultiFab& crse_rhs,
                                          const MultiFab& fine_sol, const MultiFab& fine_rhs) override;
 
@@ -132,9 +135,12 @@ public:
     virtual void compGrad (int amrlev, const Array<MultiFab*,AMREX_SPACEDIM>& grad,
                            MultiFab& sol, Location loc) const override;
 
-    virtual void applyMetricTerm (int amrlev, int mglev, MultiFab& rhs) const final override;
+    virtual void applyMetricTerm (int amrlev, int mglev, Any& rhs) const final override;
     virtual void unapplyMetricTerm (int amrlev, int mglev, MultiFab& rhs) const final override;
-    virtual void fillSolutionBC (int amrlev, MultiFab& sol, const MultiFab* crse_bcdata=nullptr) final override;
+    virtual Vector<Real> getSolvabilityOffset (int amrlev, int mglev,
+                                               Any const& rhs) const override;
+    virtual void fixSolvabilityByOffset (int amrlev, int mglev, Any& rhs,
+                                         Vector<Real> const& offset) const override;
 
     virtual void prepareForSolve () override;
 
@@ -146,6 +152,18 @@ public:
                         const Array<FArrayBox*,AMREX_SPACEDIM>& flux,
                         const FArrayBox& sol, Location loc, const int face_only=0) const = 0;
 
+    // This could be turned into template if needed.
+    void applyMetricTermToMF (int amrlev, int mglev, MultiFab& rhs) const;
+
+    virtual Real AnyNormInfMask (int amrlev, Any const& a, bool local) const override;
+
+    virtual void AnyAvgDownResAmr (int clev, Any& cres, Any const& fres) const override;
+
+    virtual void AnyInterpolationAmr (int famrlev, Any& fine, const Any& crse,
+                                      IntVect const& /*nghost*/) const override;
+
+    virtual void AnyAverageDownAndSync (Vector<Any>& sol) const override;
+
     struct BCTL {
         BoundCond type;
         Real location;
@@ -210,12 +228,17 @@ protected:
     // boundary cell flags for covered, not_covered, outside_domain
     Vector<Vector<Array<MultiMask,2*AMREX_SPACEDIM> > > m_maskvals;
 
+    Vector<std::unique_ptr<iMultiFab> > m_norm_fine_mask;
+
     mutable Vector<YAFluxRegister> m_fluxreg;
 
 private:
 
     void defineAuxData ();
     void defineBC ();
+
+    void computeVolInv () const;
+    mutable Vector<Vector<Real> > m_volinv; // used by solvability fix
 };
 
 }