src/surf/maxmin.c

   1 /* Authors: Arnaud Legrand                                                  */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4    under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include "xbt/sysdep.h"
   7 #include "xbt/error.h"
   8 #include "maxmin_private.h"
   9 #include <stdlib.h>
  10
  11 extern lmm_system_t Sys;
  12 extern lmm_constraint_t L1;
  13 extern lmm_constraint_t L2;
  14 extern lmm_constraint_t L3;
  15
  16 extern lmm_variable_t R_1_2_3;
  17 extern lmm_variable_t R_1;
  18 extern lmm_variable_t R_2;
  19 extern lmm_variable_t R_3;
  20
  21
  22 lmm_system_t lmm_system_new(void)
  23 {
  24   lmm_system_t l = NULL;
  25   s_lmm_variable_t var;
  26   s_lmm_constraint_t cnst;
  27
  28   l = xbt_new0(s_lmm_system_t, 1);
  29
  30   xbt_swag_init(&(l->variable_set),
  31                 xbt_swag_offset(var, variable_set_hookup));
  32   xbt_swag_init(&(l->constraint_set),
  33                 xbt_swag_offset(cnst, constraint_set_hookup));
  34
  35   xbt_swag_init(&(l->active_constraint_set),
  36                 xbt_swag_offset(cnst, active_constraint_set_hookup));
  37
  38   xbt_swag_init(&(l->saturated_variable_set),
  39                 xbt_swag_offset(var, saturated_variable_set_hookup));
  40   xbt_swag_init(&(l->saturated_constraint_set),
  41                 xbt_swag_offset(cnst, saturated_constraint_set_hookup));
  42
  43   return l;
  44 }
  45
  46 void lmm_system_free(lmm_system_t sys)
  47 {
  48   lmm_variable_t var = NULL;
  49   lmm_constraint_t cnst = NULL;
  50
  51   while ((var = extract_variable(sys)))
  52     lmm_var_free(sys, var);
  53
  54   while ((cnst = extract_constraint(sys)))
  55     lmm_cnst_free(sys, cnst);
  56
  57   xbt_free(sys);
  58 }
  59
  60 static void lmm_var_free(lmm_system_t sys, lmm_variable_t var)
  61 {
  62   int i;
  63   lmm_element_t elem = NULL;
  64
  65   for (i = 0; i < var->cnsts_number; i++) {
  66     elem = &var->cnsts[i];
  67     xbt_swag_extract(elem, &(elem->constraint->element_set));
  68     if (xbt_swag_size(&(elem->constraint->element_set)))
  69       make_constraint_inactive(sys, elem->constraint);
  70   }
  71   xbt_free(var->cnsts);
  72   xbt_free(var);
  73 }
  74
  75 static void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst)
  76 {
  77 /*   xbt_assert0(xbt_fifo_size(&(cnst->row)), */
  78 /*               "This list should be empty!"); */
  79   remove_active_constraint(sys, cnst);
  80   xbt_free(cnst);
  81 }
  82
  83 lmm_constraint_t lmm_constraint_new(lmm_system_t sys, void *id,
  84                                     FLOAT bound_value)
  85 {
  86   lmm_constraint_t cnst = NULL;
  87   s_lmm_element_t elem;
  88
  89   cnst = xbt_new0(s_lmm_constraint_t, 1);
  90 /*   cnst->id = id; */
  91   xbt_swag_init(&(cnst->element_set),
  92                 xbt_swag_offset(elem, element_set_hookup));
  93   xbt_swag_init(&(cnst->active_element_set),
  94                 xbt_swag_offset(elem, active_element_set_hookup));
  95
  96   cnst->bound = bound_value;
  97   cnst->usage = 0;
  98   insert_constraint(sys, cnst);
  99
 100   cnst->id = id;
 101
 102   return cnst;
 103 }
 104
 105 void lmm_constraint_free(lmm_system_t sys, lmm_constraint_t cnst)
 106 {
 107   remove_constraint(sys, cnst);
 108   lmm_cnst_free(sys, cnst);
 109 }
 110
 111 lmm_variable_t lmm_variable_new(lmm_system_t sys, void *id,
 112                                 FLOAT weight, FLOAT bound,
 113                                 int number_of_constraints)
 114 {
 115   lmm_variable_t var = NULL;
 116
 117   var = xbt_new0(s_lmm_variable_t, 1);
 118 /*   var->id = id; */
 119   var->cnsts = xbt_new0(s_lmm_element_t, number_of_constraints);
 120   var->cnsts_size = number_of_constraints;
 121   /* var->cnsts_number = 0; *//* Useless because of the calloc  */
 122   var->weight = weight;
 123   var->bound = bound;
 124   var->value = -1;
 125   insert_variable(sys, var);
 126
 127   var->id=id;
 128
 129   return var;
 130 }
 131
 132 void lmm_variable_free(lmm_system_t sys, lmm_variable_t var)
 133 {
 134   remove_variable(sys, var);
 135   lmm_var_free(sys, var);
 136 }
 137
 138 FLOAT lmm_variable_getvalue(lmm_variable_t var)
 139 {
 140   return(var->value);
 141 }
 142
 143 void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
 144                            lmm_variable_t var, FLOAT value)
 145 {
 146   lmm_element_t elem = NULL;
 147
 148   if (var->cnsts_number >= var->cnsts_size)
 149     abort();
 150
 151   elem = &(var->cnsts[var->cnsts_number++]);
 152
 153   elem->value = value;
 154   elem->constraint = cnst;
 155   elem->variable = var;
 156
 157   insert_elem_in_constraint(elem);
 158
 159   make_constraint_active(sys, cnst);
 160 }
 161
 162 static void saturated_constraints_update(lmm_system_t sys,
 163                                          lmm_constraint_t cnst,
 164                                          FLOAT * min_usage)
 165 {
 166   lmm_constraint_t useless_cnst=NULL;
 167
 168   if(cnst->remaining<=0) return;
 169   if ((*min_usage < 0) || (*min_usage > cnst->remaining / cnst->usage)) {
 170     xbt_swag_t active_elem_list = &(cnst->active_element_set);
 171
 172     *min_usage = cnst->remaining / cnst->usage;
 173
 174     while (xbt_swag_extract
 175            (useless_cnst, &(sys->saturated_constraint_set))) {
 176     }
 177     xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
 178   } else if (*min_usage == cnst->remaining / cnst->usage) {
 179     xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
 180   }
 181 }
 182
 183 static void saturated_variables_update(lmm_system_t sys)
 184 {
 185   lmm_constraint_t cnst = NULL;
 186   xbt_swag_t cnst_list = NULL;
 187   lmm_element_t elem = NULL;
 188   xbt_swag_t elem_list = NULL;
 189
 190   cnst_list = &(sys->saturated_constraint_set);
 191   while((cnst=xbt_swag_getFirst(cnst_list))) {
 192 /*   xbt_swag_foreach(cnst, cnst_list) { */
 193     elem_list = &(cnst->active_element_set);
 194     xbt_swag_foreach(elem, elem_list)
 195         xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
 196     xbt_swag_extract(cnst,cnst_list);
 197   }
 198
 199 }
 200
 201 void lmm_solve(lmm_system_t sys)
 202 {
 203   lmm_variable_t var = NULL;
 204   lmm_constraint_t cnst = NULL;
 205   lmm_element_t elem = NULL;
 206   xbt_swag_t cnst_list = NULL;
 207   xbt_swag_t var_list = NULL;
 208   xbt_swag_t elem_list = NULL;
 209   FLOAT min_usage = -1;
 210
 211   /* Init */
 212   var_list=&(sys->variable_set);
 213   xbt_swag_foreach(var, var_list) {
 214     var->value = -1;
 215   }
 216
 217
 218   /* Compute Usage and store the variables that reach the maximum */
 219
 220   cnst_list = &(sys->active_constraint_set);
 221   xbt_swag_foreach(cnst, cnst_list) {
 222     /* INIT */
 223     elem_list = &(cnst->element_set);
 224     cnst->remaining = cnst->bound;
 225     cnst->usage = 0;
 226     xbt_swag_foreach(elem, elem_list) {
 227       cnst->usage += elem->value / elem->variable->weight;
 228       insert_active_elem_in_constraint(elem);
 229     }
 230
 231     /* Saturated constraints update */
 232     saturated_constraints_update(sys, cnst, &min_usage);
 233   }
 234
 235   saturated_variables_update(sys);
 236
 237   /* Saturated variables update */
 238
 239   do {
 240     /* Fix the variables that have to be */
 241     var_list=&(sys->saturated_variable_set);
 242
 243
 244     xbt_swag_foreach(var, var_list) {
 245       /* First check if some of these variables have reach their upper
 246          bound and update min_usage accordingly. */
 247       if((var->bound>0) && (var->bound / var->weight < min_usage)) {
 248         min_usage = var->bound / var->weight;
 249       }
 250     }
 251
 252
 253     while((var=xbt_swag_getFirst(var_list))) {
 254       int i ;
 255
 256       var->value = min_usage / var->weight;
 257
 258       /* Update usage */
 259
 260       for (i = 0; i < var->cnsts_number; i++) {
 261         elem = &var->cnsts[i];
 262         cnst = elem->constraint;
 263         cnst->remaining -= elem->value * var->value;
 264         cnst->usage -= elem->value / var->weight;
 265         remove_active_elem_in_constraint(elem);
 266       }
 267       xbt_swag_extract(var,var_list);
 268     }
 269
 270     /* Find out which variables reach the maximum */
 271     cnst_list = &(sys->active_constraint_set);
 272     min_usage = -1;
 273     xbt_swag_foreach(cnst, cnst_list) {
 274       saturated_constraints_update(sys, cnst, &min_usage);
 275     }
 276     saturated_variables_update(sys);
 277
 278   } while (xbt_swag_size(&(sys->saturated_variable_set)));
 279 }
 280
 281 /* Not a O(1) function */
 282
 283 void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
 284                 lmm_variable_t var, FLOAT value)
 285 {
 286   int i;
 287   lmm_element_t elem = NULL;
 288
 289   for (i = 0; i < var->cnsts_number; i++)
 290     if(var->cnsts[i].constraint==cnst) {
 291       elem->value =value;
 292       return;
 293     }
 294 }
 295
 296 void lmm_update_variable_bound(lmm_variable_t var, FLOAT bound)
 297 {
 298   var->bound=bound;
 299 }
 300
 301 void lmm_update_variable_weight(lmm_variable_t var, FLOAT weight)
 302 {
 303   var->weight=weight;
 304 }
 305
 306 void lmm_update_constraint_bound(lmm_constraint_t cnst,
 307                                  FLOAT bound)
 308 {
 309   cnst->bound=bound;
 310 }
 311
 312
 313
 314 /* void lmm_print(lmm_system_t sys) */
 315 /* { */
 316 /*   lmm_variable_t var = NULL; */
 317 /*   lmm_constraint_t cnst = NULL; */
 318 /*   lmm_element_t elem = NULL; */
 319 /*   xbt_swag_t cnst_list = NULL; */
 320 /*   xbt_swag_t var_list = NULL; */
 321 /*   xbt_swag_t elem_list = NULL; */
 322
 323 /*   var_list = &(sys->variable_set); */
 324 /*   xbt_swag_foreach(var, var_list) { */
 325 /*     printf("%s : {\n",var->id); */
 326 /*     printf("\t %s : {\n",var->id); */
 327 /*   } */
 328 /* } */