1: #pragma once

  3: #include <petsc/private/pcimpl.h>
  4: #include <petsc/private/matisimpl.h>
  5: #include <petscksp.h>

  7: /*
  8:    Context (data structure) common for all Iterative Substructuring preconditioners.
  9: */

 11: typedef struct {
 12:   /*
 13:      In naming the variables, we adopted the following convention:
 14:      * B - stands for interface nodes;
 15:      * I - stands for interior nodes;
 16:      * D - stands for Dirichlet (by extension, refers to interior
 17:            nodes) and
 18:      * N - stands for Neumann (by extension, refers to all local
 19:            nodes, interior plus interface).
 20:      In some cases, I or D would apply equally well (e.g. vec1_D).
 21:   */

 23:   PetscInt n;          /* number of nodes (interior+interface) in this subdomain */
 24:   PetscInt n_B;        /* number of interface nodes in this subdomain */
 25:   IS       is_B_local, /* local (sequential) index sets for interface (B) and interior (I) nodes */
 26:     is_I_local, is_B_global, is_I_global;

 28:   Mat A_II, A_IB, /* local (sequential) submatrices */
 29:     A_BI, A_BB;
 30:   Mat pA_II;
 31:   Vec D;     /* diagonal scaling "matrix" (stored as a vector, since it's diagonal) */
 32:   KSP ksp_N, /* linear solver contexts */
 33:     ksp_D;
 34:   Vec vec1_N, /* local (sequential) work vectors */
 35:     vec2_N, vec1_D, vec2_D, vec3_D, vec4_D, vec1_B, vec2_B, vec3_B, vec1_global;

 37:   PetscScalar *work_N;
 38:   VecScatter   N_to_D;      /* scattering context from all local nodes to local interior nodes */
 39:   VecScatter   global_to_D; /* scattering context from global to local interior nodes */
 40:   VecScatter   N_to_B;      /* scattering context from all local nodes to local interface nodes */
 41:   VecScatter   global_to_B; /* scattering context from global to local interface nodes */
 42:   PetscBool    pure_neumann;
 43:   PetscScalar  scaling_factor;
 44:   PetscBool    use_stiffness_scaling;

 46:   ISLocalToGlobalMapping mapping;
 47:   PetscInt               n_neigh;  /* should use PetscMPIInt number of neighbours this subdomain/MPI process has (INCLUDING the subdomain itself). */
 48:   PetscInt              *neigh;    /* list of neighbouring subdomains, MPI processes  */
 49:   PetscInt              *n_shared; /* n_shared[j] is the number of nodes shared with subdomain neigh[j] */
 50:   PetscInt             **shared;   /* shared[j][i] is the local index of the i-th node shared with subdomain neigh[j] */
 51:   /*
 52:      It is necessary some consistency in the
 53:      numbering of the shared edges from each side.
 54:      For instance:

 56:      +-------+-------+
 57:      |   k   |   l   | subdomains k and l are neighbours
 58:      +-------+-------+

 60:      Let i and j be s.t. proc[k].neigh[i]==l and
 61:                          proc[l].neigh[j]==k.

 63:      We need:
 64:      proc[k].loc_to_glob(proc[k].shared[i][m]) == proc[l].loc_to_glob(proc[l].shared[j][m])
 65:      for all 0 <= m < proc[k].n_shared[i], or equiv'ly, for all 0 <= m < proc[l].n_shared[j]
 66:   */
 67:   ISLocalToGlobalMapping BtoNmap;
 68:   PetscBool              reusesubmatrices;
 69: } PC_IS;