/********************************************************
% 
% Written by:
% -- 
% John L. Weatherwax                2006-05-29
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

*/

#include <math.h>
#include <stdio.h>
#include "mpi.h"
#include "global_grid.h"
#include "sim_consts.h"
#include "evictParticles.h"

/* 
*/ 
void evictParticles(void){

  const int TAG_OFFSET=3*9+1; 
  MPI_Status status; 

  /* 
     Send NW <-> Receive SE 
  */ 
  /*printf("Send NW <-> Receive SE\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[NW]         , 4*procInfo.numToEvict[NW]         , MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+0, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[SE], 4*procInfo.numRefugeeToReceive[SE], MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+0, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[SE], 4*procInfo.numRefugeeToReceive[SE], MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+0, MPI_COMM_WORLD, &status);
    MPI_Send(procInfo.partDataToEvict[NW]         , 4*procInfo.numToEvict[NW]         , MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+0, MPI_COMM_WORLD); 
  } 

  /* 
     Send N <-> Receive S 
  */ 
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[N]         , 4*procInfo.numToEvict[N]         , MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+1, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[S], 4*procInfo.numRefugeeToReceive[S], MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+1, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[S], 4*procInfo.numRefugeeToReceive[S], MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+1, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.partDataToEvict[N]         , 4*procInfo.numToEvict[N]         , MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+1, MPI_COMM_WORLD); 
  }

  /* 
     Send NE <-> Receive SW 
  */ 
  /*printf("Send NE <-> Receive SW\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[NE]         , 4*procInfo.numToEvict[NE]         , MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+2, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[SW], 4*procInfo.numRefugeeToReceive[SW], MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+2, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[SW], 4*procInfo.numRefugeeToReceive[SW], MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+2, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.partDataToEvict[NE]         ,  4*procInfo.numToEvict[NE]        , MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+2, MPI_COMM_WORLD);     
  }

  /* 
     Send W <-> Receive E 
  */ 
  if( procInfo.my_col % 2 == 0 ){    /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[W]         , 4*procInfo.numToEvict[W]         , MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+3, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[E], 4*procInfo.numRefugeeToReceive[E], MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+3, MPI_COMM_WORLD, &status);
  }else{                             /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[E], 4*procInfo.numRefugeeToReceive[E], MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+3, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.partDataToEvict[W]         , 4*procInfo.numToEvict[W]         , MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+3, MPI_COMM_WORLD); 
  }

  /* No sending to the IDENTITY */ 

  /* 
     Send E <-> Receive W 
  */ 
  if( procInfo.my_col % 2 == 0 ){    /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[E]         , 4*procInfo.numToEvict[E]         , MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+5, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[W], 4*procInfo.numRefugeeToReceive[W], MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+5, MPI_COMM_WORLD, &status);
  }else{                             /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[W], 4*procInfo.numRefugeeToReceive[W], MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+5, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.partDataToEvict[E]         , 4*procInfo.numToEvict[E]         , MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+5, MPI_COMM_WORLD); 
  }

  /* 
     Send SW <-> Receive NE 
  */ 
  /*printf("Send SW <-> Receive NE\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[SW]         , 4*procInfo.numToEvict[SW]         , MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+6, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[NE], 4*procInfo.numRefugeeToReceive[NE], MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+6, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[NE], 4*procInfo.numRefugeeToReceive[NE], MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+6, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.partDataToEvict[SW]         , 4*procInfo.numToEvict[SW]         , MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+6, MPI_COMM_WORLD);     
  }

  /* 
     Send S <-> Receive N 
  */ 
  if( procInfo.my_row % 2 == 0 ){    /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[S]         , 4*procInfo.numToEvict[S]         , MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+7, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[N], 4*procInfo.numRefugeeToReceive[N], MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+7, MPI_COMM_WORLD, &status);
  }else{                             /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[N], 4*procInfo.numRefugeeToReceive[N], MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+7, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.partDataToEvict[S]         , 4*procInfo.numToEvict[S]         , MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+7, MPI_COMM_WORLD); 
  }

  /* 
     Send SE <-> Receive NW 
  */ 
  /*printf("Send SE <-> Receive NW\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.partDataToEvict[SE]         , 4*procInfo.numToEvict[SE]         , MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+8, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.partRefugeeDataToReceive[NW], 4*procInfo.numRefugeeToReceive[NW], MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+8, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.partRefugeeDataToReceive[NW], 4*procInfo.numRefugeeToReceive[NW], MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+8, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.partDataToEvict[SE]         , 4*procInfo.numToEvict[SE]         , MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+8, MPI_COMM_WORLD);     
  }

}