include/split.h

   1 /*
   2  *
   3  *                This source code is part of
   4  *
   5  *                 G   R   O   M   A   C   S
   6  *
   7  *          GROningen MAchine for Chemical Simulations
   8  *
   9  *                        VERSION 3.2.0
  10  * Written by David van der Spoel, Erik Lindahl, Berk Hess, and others.
  11  * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
  12  * Copyright (c) 2001-2004, The GROMACS development team,
  13  * check out http://www.gromacs.org for more information.
  14
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version 2
  18  * of the License, or (at your option) any later version.
  19  *
  20  * If you want to redistribute modifications, please consider that
  21  * scientific software is very special. Version control is crucial -
  22  * bugs must be traceable. We will be happy to consider code for
  23  * inclusion in the official distribution, but derived work must not
  24  * be called official GROMACS. Details are found in the README & COPYING
  25  * files - if they are missing, get the official version at www.gromacs.org.
  26  *
  27  * To help us fund GROMACS development, we humbly ask that you cite
  28  * the papers on the package - you can find them in the top README file.
  29  *
  30  * For more info, check our website at http://www.gromacs.org
  31  *
  32  * And Hey:
  33  * Gromacs Runs On Most of All Computer Systems
  34  */
  35
  36 #ifndef _split_h
  37 #define _split_h
  38
  39 /*
  40  * Determine on which node a particle should reside and on which
  41  * node is also should be available. The distribution algorithm
  42  * should account for the actual ring architecture and how nodes
  43  * are numbered. The typedef t_splitd has two separate structures that
  44  * describe the distribution:
  45  *
  46  * The nodeinfo part describes which node containst which particles,
  47  * while the nodeids part describes on which node(s) a particle can be
  48  * found and what local particle number is assigned to it.
  49  *
  50  */
  51
  52 #include <stdio.h>
  53 #include "typedefs.h"
  54
  55 #ifdef __cplusplus
  56 extern "C" {
  57 #endif
  58
  59 typedef enum {SPLIT_NONE,SPLIT_SORTX,SPLIT_REDUCE,SPLIT_NR} t_splitalg;
  60
  61 typedef struct
  62 {
  63   int hid;
  64   atom_id *nodeid;
  65 } t_nodeids;
  66
  67 typedef struct
  68 {
  69   int nr;               /* Length of the long list.                         */
  70   int *lst;             /* The actual list.                                 */
  71 } t_nlist;
  72
  73 typedef struct
  74 {
  75   t_nlist home;         /* List of home particles.                          */
  76 } t_nodeinfo;
  77
  78 typedef struct
  79 {
  80   int nnodes;           /* Number of nodes this splitinfo is for.      */
  81   t_nodeinfo *nodeinfo; /* Home and available particles for each node. */
  82   int nnodeids;         /* Number of particles this splitinfo is for.       */
  83   t_nodeids *nodeids;   /* List of node id's for every particle,       */
  84                         /* entry[nodeid] gives the local atom id (NO_ATID if*/
  85                         /* not available). Entry[MAXNODES] contains home    */
  86                         /* node's id.                                  */
  87 } t_splitd;
  88
  89 void init_splitd(t_splitd *splitd,int nnodes,int nnodeids);
  90      /*
  91       * Initialises the splitd data structure for the specified number of
  92       * nodes (nnodes) and number of atoms (nnodeids).
  93       */
  94
  95 void make_splitd(t_splitalg algorithm,int nnodes,t_topology *top,
  96                         rvec *x,t_splitd *splitd,char *loadfile);
  97      /*
  98       * Initialises the splitd data structure for the specified number of
  99       * nodes (nnodes) and number of atoms (top) and fills it using
 100       * the specified algorithm (algorithm):
 101       *
 102       *    SPLIT_NONE   : Generate partial systems by dividing it into nnodes
 103       *                   consecutive, equal, parts without any intelligence.
 104       *    SPLIT_SORTX  : Like SPLIT_NONE but sort the coordinates before
 105       *                   dividing the system into nnodes consecutive, equal,
 106       *                   parts.
 107       *    SPLIT_REDUCE : Like SPLIT_NONE but minimise the bond lengths, i.e
 108       *                   invoke the reduce algorithm before dividing the
 109       *                   system into nnodes consecutive, equal, parts.
 110       *
 111       * The topology (top) and the coordinates (x) are not modified. The
 112       * calculations of bonded forces are assigned to the node with
 113       * the highest id that has one of the needed particles as home particle.
 114       */
 115
 116 long wr_split(FILE *fp,t_splitd *splitd);
 117      /*
 118       * Writes the split descriptor (splitd) to the file specified by fp.
 119       */
 120
 121 long rd_split(FILE *fp,t_splitd *splitd);
 122      /*
 123       * Reads the split descriptor (splitd) from the file specified by fp.
 124       */
 125
 126 void rm_splitd(t_splitd *splitd);
 127      /*
 128       * Frees all allocated space for the splitd data structure.
 129       */
 130
 131 void pr_splitd(FILE *fp,int indent,char *title,t_splitd *splitd);
 132      /*
 133       * This routine prints out a (human) readable representation of
 134       * the split descriptor to the file fp. Ident specifies the
 135       * number of spaces the text should be indented. Title is used
 136       * to print a header text.
 137       */
 138
 139 void split_topology(t_splitalg algorithm,int nnodes,t_topology *top,
 140                            rvec x[],char *loadfile);
 141      /*
 142       * Distributes the non-bonded forces defined in top over nnodes nodes
 143       * using the algoritm specified by algorithm. The distribution is made
 144       * by creating a split descriptor and then putting a bonded force on the
 145       * highest home node number of the paricles involved.
 146       */
 147
 148 #ifdef __cplusplus
 149 }
 150 #endif
 151
 152 #endif  /* _split_h */