1: /*$Id: pmap.c,v 1.21 2001/07/20 21:18:16 bsmith Exp $*/

  3: /*
  4:    This file contains routines for basic map object implementation.
  5: */

 7:  #include src/vec/vecimpl.h

  9: #undef __FUNCT__  
 11: int PetscMapDestroy_MPI(PetscMap m)
 12: {
 14:   return(0);
 15: }

 17: static struct _PetscMapOps DvOps = {
 18:   PETSC_NULL,
 19:   PetscMapDestroy_MPI,
 20: };

 22: EXTERN_C_BEGIN
 23: #undef __FUNCT__  
 25: int PetscMapCreate_MPI(PetscMap m)
 26: {
 27:   int rank,size;
 28:   int p;

 32:   PetscMemcpy(m->ops, &DvOps, sizeof(DvOps));

 34:   MPI_Comm_size(m->comm, &size);
 35:   MPI_Comm_rank(m->comm, &rank);
 36:   PetscSplitOwnership(m->comm,&m->n,&m->N);
 37:   PetscMalloc((size+1)*sizeof(int), &m->range);
 38:   MPI_Allgather(&m->n, 1, MPI_INT, m->range+1, 1, MPI_INT, m->comm);

 40:   m->range[0] = 0;
 41:   for(p = 2; p <= size; p++) {
 42:     m->range[p] += m->range[p-1];
 43:   }

 45:   m->rstart = m->range[rank];
 46:   m->rend   = m->range[rank+1];
 47:   return(0);
 48: }
 49: EXTERN_C_END

 51: EXTERN_C_BEGIN
 52: #undef __FUNCT__  
 54: int PetscMapSerialize_MPI(MPI_Comm comm, PetscMap *map, PetscViewer viewer, PetscTruth store)
 55: {
 56:   PetscMap m;
 57:   int      fd;
 58:   int      n, N, checkN;
 59:   int      numProcs;
 60:   int      ierr;

 63:   PetscViewerBinaryGetDescriptor(viewer, &fd);
 64:   if (store) {
 65:     m    = *map;
 66:     MPI_Comm_size(m->comm, &numProcs);
 67:     PetscBinaryWrite(fd, &m->n,      1,          PETSC_INT, 0);
 68:     PetscBinaryWrite(fd, &m->N,      1,          PETSC_INT, 0);
 69:     PetscBinaryWrite(fd, &m->rstart, 1,          PETSC_INT, 0);
 70:     PetscBinaryWrite(fd, &m->rend,   1,          PETSC_INT, 0);
 71:     PetscBinaryWrite(fd,  m->range,  numProcs+1, PETSC_INT, 0);
 72:   } else {
 73:     PetscBinaryRead(fd, &n,         1,          PETSC_INT);
 74:     PetscBinaryRead(fd, &N,         1,          PETSC_INT);
 75:     MPI_Allreduce(&n, &checkN, 1, MPI_INT, MPI_SUM, comm);
 76:     if (checkN != N) SETERRQ(PETSC_ERR_ARG_CORRUPT, "Invalid partition");
 77:     PetscMapCreate(comm, &m);
 78:     PetscMapSetLocalSize(m, n);
 79:     PetscMapSetSize(m, N);
 80:     MPI_Comm_size(comm, &numProcs);
 81:     PetscMalloc((numProcs+1) * sizeof(int), &m->range);
 82:     PetscBinaryRead(fd, &m->rstart, 1,          PETSC_INT);
 83:     PetscBinaryRead(fd, &m->rend,   1,          PETSC_INT);
 84:     PetscBinaryRead(fd,  m->range,  numProcs+1, PETSC_INT);

 86:     *map = m;
 87:   }

 89:   return(0);
 90: }
 91: EXTERN_C_END

 93: #undef __FUNCT__  
 95: /*@C
 96:    PetscMapCreateMPI - Creates a map object.

 98:    Collective on MPI_Comm
 99:  
100:    Input Parameters:
101: +  comm - the MPI communicator to use 
102: .  n - local vector length (or PETSC_DECIDE to have calculated if N is given)
103: -  N - global vector length (or PETSC_DECIDE to have calculated if n is given)

105:    Output Parameter:
106: .  mm - the map object

108:    Suggested by:
109:    Robert Clay and Alan Williams, developers of ISIS++, Sandia National Laboratories.

111:    Level: developer

113:    Concepts: maps^creating

115: .seealso: PetscMapDestroy(), PetscMapGetLocalSize(), PetscMapGetSize(), PetscMapGetGlobalRange(),
116:           PetscMapGetLocalRange()

118: @*/
119: int PetscMapCreateMPI(MPI_Comm comm,int n,int N,PetscMap *m)
120: {

124:   PetscMapCreate(comm, m);
125:   PetscMapSetLocalSize(*m, n);
126:   PetscMapSetSize(*m, N);
127:   PetscMapSetType(*m, MAP_MPI);
128:   return(0);
129: }