src/gmxlib/selection/mempool.c

   1 /*
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   3  *                This source code is part of
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  11  * Copyright (c) 2001-2009, The GROMACS development team,
  12  * check out http://www.gromacs.org for more information.
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  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
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  31 /*! \internal \file
  32  * \brief Memory pooling for selection evaluation.
  33  *
  34  * \todo
  35  * Document these functions.
  36  */
  37 #ifdef HAVE_CONFIG_H
  38 #include <config.h>
  39 #endif
  40
  41 #include <assert.h>
  42 #include <stdlib.h>
  43
  44 #include <gmx_fatal.h>
  45 #include <smalloc.h>
  46
  47 #include <indexutil.h>
  48
  49 #include "mempool.h"
  50
  51 #define ALIGN_STEP 8
  52
  53 typedef struct gmx_sel_mempool_block_t
  54 {
  55     void                       *ptr;
  56     size_t                      size;
  57 } gmx_sel_mempool_block_t;
  58
  59 struct gmx_sel_mempool_t
  60 {
  61     size_t                      currsize;
  62     size_t                      freesize;
  63     char                       *buffer;
  64     char                       *freeptr;
  65     int                         nblocks;
  66     gmx_sel_mempool_block_t    *blockstack;
  67     size_t                      blockstack_nalloc;
  68     size_t                      maxsize;
  69 };
  70
  71 int
  72 _gmx_sel_mempool_create(gmx_sel_mempool_t **mpp)
  73 {
  74     gmx_sel_mempool_t *mp;
  75
  76     snew(mp, 1);
  77     mp->currsize          = 0;
  78     mp->freesize          = 0;
  79     mp->buffer            = NULL;
  80     mp->freeptr           = NULL;
  81     mp->nblocks           = 0;
  82     mp->blockstack        = NULL;
  83     mp->blockstack_nalloc = 0;
  84     mp->maxsize           = 0;
  85     *mpp = mp;
  86     return 0;
  87 }
  88
  89 void
  90 _gmx_sel_mempool_destroy(gmx_sel_mempool_t *mp)
  91 {
  92     if (!mp->buffer)
  93     {
  94         int  i;
  95
  96         for (i = 0; i < mp->nblocks; ++i)
  97         {
  98             sfree(mp->blockstack[i].ptr);
  99         }
 100     }
 101     sfree(mp->buffer);
 102     sfree(mp->blockstack);
 103     sfree(mp);
 104 }
 105
 106 int
 107 _gmx_sel_mempool_alloc(gmx_sel_mempool_t *mp, void **ptrp, size_t size)
 108 {
 109     void   *ptr = NULL;
 110     size_t  size_walign;
 111
 112     *ptrp = NULL;
 113     size_walign = ((size + ALIGN_STEP - 1) / ALIGN_STEP) * ALIGN_STEP;
 114     if (mp->buffer)
 115     {
 116         if (mp->freesize < size)
 117         {
 118             gmx_bug("out of memory pool memory");
 119             return ENOMEM;
 120         }
 121         ptr = mp->freeptr;
 122         mp->freeptr  += size_walign;
 123         mp->freesize -= size_walign;
 124         mp->currsize += size_walign;
 125     }
 126     else
 127     {
 128         ptr = malloc(size);
 129         if (!ptr)
 130         {
 131             gmx_mem("out of memory");
 132             return ENOMEM;
 133         }
 134         mp->currsize += size_walign;
 135         if (mp->currsize > mp->maxsize)
 136         {
 137             mp->maxsize = mp->currsize;
 138         }
 139     }
 140
 141     if (mp->nblocks >= mp->blockstack_nalloc)
 142     {
 143         mp->blockstack_nalloc = mp->nblocks + 10;
 144         srenew(mp->blockstack, mp->blockstack_nalloc);
 145     }
 146     mp->blockstack[mp->nblocks].ptr  = ptr;
 147     mp->blockstack[mp->nblocks].size = size_walign;
 148     mp->nblocks++;
 149
 150     *ptrp = ptr;
 151     return 0;
 152 }
 153
 154 void
 155 _gmx_sel_mempool_free(gmx_sel_mempool_t *mp, void *ptr)
 156 {
 157     int size;
 158
 159     if (ptr == NULL)
 160     {
 161         return;
 162     }
 163     assert(mp->nblocks > 0 && mp->blockstack[mp->nblocks - 1].ptr == ptr);
 164     mp->nblocks--;
 165     size = mp->blockstack[mp->nblocks].size;
 166     mp->currsize -= size;
 167     if (mp->buffer)
 168     {
 169         mp->freeptr = ptr;
 170         mp->freesize += size;
 171     }
 172     else
 173     {
 174         sfree(ptr);
 175     }
 176 }
 177
 178 int
 179 _gmx_sel_mempool_reserve(gmx_sel_mempool_t *mp, size_t size)
 180 {
 181     assert(mp->nblocks == 0 && !mp->buffer);
 182     if (size == 0)
 183     {
 184         size = mp->maxsize;
 185     }
 186     mp->buffer = (char *)malloc(size);
 187     if (!mp->buffer)
 188     {
 189         gmx_mem("out of memory");
 190         return ENOMEM;
 191     }
 192     mp->freesize = size;
 193     mp->freeptr  = mp->buffer;
 194     return 0;
 195 }
 196
 197 int
 198 _gmx_sel_mempool_alloc_group(gmx_sel_mempool_t *mp, gmx_ana_index_t *g,
 199                              int isize)
 200 {
 201     return _gmx_sel_mempool_alloc(mp, (void **)&g->index,
 202                                   sizeof(*g->index)*isize);
 203 }
 204
 205 void
 206 _gmx_sel_mempool_free_group(gmx_sel_mempool_t *mp, gmx_ana_index_t *g)
 207 {
 208     _gmx_sel_mempool_free(mp, g->index);
 209     g->index = NULL;
 210 }