ga_get.c

The example for Boor USING MPI2

#include "ga.h"
int ga_get( GA ga, int ilo, int ihigh, int jlo, int jhigh, void *buf )
{
  int      jcur, jfirst, jlast, j, rank;
  MPI_Aint disp;

  jcur = jlo;
  while (jcur <= jhigh) {
    rank   = (jcur - 1) /ga->chunk2;
    jfirst = rank * ga->chunk2 + 1;
    jlast  = (rank + 1) * ga->chunk2;
    if (jlast > jhigh) jlast = jhigh;

    /* The locks on ga->lock_win are required only when 
       ga_read_inc is used */
    MPE_Mutex_lock( rank, ga->lock_win );

    /* Using lock_shared allows other get accesses to proceed */
    MPI_Win_lock( MPI_LOCK_SHARED, rank, MPI_MODE_NOCHECK, ga->ga_win );
    for (j=jcur; j<=jlast; j++) {
      disp = (j - jfirst) * ga->dim1 + (ilo - 1);
      MPI_Get( buf, ihigh - ilo + 1, ga->dtype, 
               rank, disp, ihigh - ilo + 1, ga->dtype, ga->ga_win );
      buf = (void *)( ((char *)buf) + 
                      (ihigh - ilo + 1) *  ga->dtype_size );
    }
    MPI_Win_unlock( rank, ga->ga_win );

    MPE_Mutex_unlock( rank, ga->lock_win );
    jcur = jlast + 1;
  }
  return 0;
}