include/split.h

   1 /*
   2  * $Id$
   3  *
   4  *                This source code is part of
   5  *
   6  *                 G   R   O   M   A   C   S
   7  *
   8  *          GROningen MAchine for Chemical Simulations
   9  *
  10  *                        VERSION 3.1
  11  * Copyright (c) 1991-2001, University of Groningen, The Netherlands
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * If you want to redistribute modifications, please consider that
  18  * scientific software is very special. Version control is crucial -
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  22  * files - if they are missing, get the official version at www.gromacs.org.
  23  *
  24  * To help us fund GROMACS development, we humbly ask that you cite
  25  * the papers on the package - you can find them in the top README file.
  26  *
  27  * For more info, check our website at http://www.gromacs.org
  28  *
  29  * And Hey:
  30  * Getting the Right Output Means no Artefacts in Calculating Stuff
  31  */
  32
  33 #ifndef _split_h
  34 #define _split_h
  35
  36 #ifdef HAVE_CONFIG_H
  37 #include <config.h>
  38 #endif
  39
  40 /*
  41  * Determine on which node a particle should reside and on which
  42  * node is also should be available. The distribution algorithm
  43  * should account for the actual ring architecture and how nodes
  44  * are numbered. The typedef t_splitd has two separate structures that
  45  * describe the distribution:
  46  *
  47  * The nodeinfo part describes which node containst which particles,
  48  * while the nodeids part describes on which node(s) a particle can be
  49  * found and what local particle number is assigned to it.
  50  *
  51  */
  52
  53 #include <stdio.h>
  54 #include "typedefs.h"
  55
  56 typedef enum {SPLIT_NONE,SPLIT_SORTX,SPLIT_REDUCE,SPLIT_NR} t_splitalg;
  57
  58 typedef struct
  59 {
  60   int hid;
  61   atom_id *nodeid;
  62 } t_nodeids;
  63
  64 typedef struct
  65 {
  66   int nr;               /* Length of the long list.                         */
  67   int *lst;             /* The actual list.                                 */
  68 } t_nlist;
  69
  70 typedef struct
  71 {
  72   t_nlist home;         /* List of home particles.                          */
  73 } t_nodeinfo;
  74
  75 typedef struct
  76 {
  77   int nnodes;           /* Number of nodes this splitinfo is for.      */
  78   t_nodeinfo *nodeinfo; /* Home and available particles for each node. */
  79   int nnodeids;         /* Number of particles this splitinfo is for.       */
  80   t_nodeids *nodeids;   /* List of node id's for every particle,       */
  81                         /* entry[nodeid] gives the local atom id (NO_ATID if*/
  82                         /* not available). Entry[MAXNODES] contains home    */
  83                         /* node's id.                                  */
  84 } t_splitd;
  85
  86 extern void init_splitd(t_splitd *splitd,int nnodes,int nnodeids);
  87      /*
  88       * Initialises the splitd data structure for the specified number of
  89       * nodes (nnodes) and number of atoms (nnodeids).
  90       */
  91
  92 extern void make_splitd(t_splitalg algorithm,int nnodes,t_topology *top,
  93                         rvec *x,t_splitd *splitd,char *loadfile);
  94      /*
  95       * Initialises the splitd data structure for the specified number of
  96       * nodes (nnodes) and number of atoms (top) and fills it using
  97       * the specified algorithm (algorithm):
  98       *
  99       *    SPLIT_NONE   : Generate partial systems by dividing it into nnodes
 100       *                   consecutive, equal, parts without any intelligence.
 101       *    SPLIT_SORTX  : Like SPLIT_NONE but sort the coordinates before
 102       *                   dividing the system into nnodes consecutive, equal,
 103       *                   parts.
 104       *    SPLIT_REDUCE : Like SPLIT_NONE but minimise the bond lengths, i.e
 105       *                   invoke the reduce algorithm before dividing the
 106       *                   system into nnodes consecutive, equal, parts.
 107       *
 108       * The topology (top) and the coordinates (x) are not modified. The
 109       * calculations of bonded forces are assigned to the node with
 110       * the highest id that has one of the needed particles as home particle.
 111       */
 112
 113 extern long wr_split(FILE *fp,t_splitd *splitd);
 114      /*
 115       * Writes the split descriptor (splitd) to the file specified by fp.
 116       */
 117
 118 extern long rd_split(FILE *fp,t_splitd *splitd);
 119      /*
 120       * Reads the split descriptor (splitd) from the file specified by fp.
 121       */
 122
 123 extern void rm_splitd(t_splitd *splitd);
 124      /*
 125       * Frees all allocated space for the splitd data structure.
 126       */
 127
 128 extern void pr_splitd(FILE *fp,int indent,char *title,t_splitd *splitd);
 129      /*
 130       * This routine prints out a (human) readable representation of
 131       * the split descriptor to the file fp. Ident specifies the
 132       * number of spaces the text should be indented. Title is used
 133       * to print a header text.
 134       */
 135
 136 extern void split_topology(t_splitalg algorithm,int nnodes,t_topology *top,
 137                            rvec x[],char *loadfile);
 138      /*
 139       * Distributes the non-bonded forces defined in top over nnodes nodes
 140       * using the algoritm specified by algorithm. The distribution is made
 141       * by creating a split descriptor and then putting a bonded force on the
 142       * highest home node number of the paricles involved.
 143       */
 144
 145
 146 #endif  /* _split_h */