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_remove(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                                     xbt_maxmin_float_t 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                                 xbt_maxmin_float_t weight,
 113                                 xbt_maxmin_float_t bound,
 114                                 int number_of_constraints)
 115 {
 116   lmm_variable_t var = NULL;
 117
 118   var = xbt_new0(s_lmm_variable_t, 1);
 119 /*   var->id = id; */
 120   var->cnsts = xbt_new0(s_lmm_element_t, number_of_constraints);
 121   var->cnsts_size = number_of_constraints;
 122   /* var->cnsts_number = 0; *//* Useless because of the calloc  */
 123   var->weight = weight;
 124   var->bound = bound;
 125   var->value = -1;
 126   insert_variable(sys, var);
 127
 128   var->id = id;
 129
 130   return var;
 131 }
 132
 133 void lmm_variable_free(lmm_system_t sys, lmm_variable_t var)
 134 {
 135   remove_variable(sys, var);
 136   lmm_var_free(sys, var);
 137 }
 138
 139 xbt_maxmin_float_t lmm_variable_getvalue(lmm_variable_t var)
 140 {
 141   return (var->value);
 142 }
 143
 144 void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
 145                 lmm_variable_t var, xbt_maxmin_float_t value)
 146 {
 147   lmm_element_t elem = NULL;
 148
 149   if (var->cnsts_number >= var->cnsts_size)
 150     abort();
 151
 152   elem = &(var->cnsts[var->cnsts_number++]);
 153
 154   elem->value = value;
 155   elem->constraint = cnst;
 156   elem->variable = var;
 157
 158   insert_elem_in_constraint(elem);
 159
 160   make_constraint_active(sys, cnst);
 161 }
 162
 163 static void saturated_constraints_update(lmm_system_t sys,
 164                                          lmm_constraint_t cnst,
 165                                          xbt_maxmin_float_t * min_usage)
 166 {
 167   lmm_constraint_t useless_cnst = NULL;
 168
 169   if (cnst->remaining <= 0)
 170     return;
 171   if ((*min_usage < 0) || (*min_usage > cnst->remaining / cnst->usage)) {
 172     xbt_swag_t active_elem_list = &(cnst->active_element_set);
 173
 174     *min_usage = cnst->remaining / cnst->usage;
 175
 176     while ((useless_cnst = xbt_swag_getFirst(&(sys->saturated_constraint_set))))
 177       xbt_swag_remove(useless_cnst, &(sys->saturated_constraint_set));
 178
 179     xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
 180   } else if (*min_usage == cnst->remaining / cnst->usage) {
 181     xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
 182   }
 183 }
 184
 185 static void saturated_variables_update(lmm_system_t sys)
 186 {
 187   lmm_constraint_t cnst = NULL;
 188   xbt_swag_t cnst_list = NULL;
 189   lmm_element_t elem = NULL;
 190   xbt_swag_t elem_list = NULL;
 191
 192   cnst_list = &(sys->saturated_constraint_set);
 193   while ((cnst = xbt_swag_getFirst(cnst_list))) {
 194 /*   xbt_swag_foreach(cnst, cnst_list) { */
 195     elem_list = &(cnst->active_element_set);
 196     xbt_swag_foreach(elem, elem_list)
 197         xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
 198     xbt_swag_remove(cnst, cnst_list);
 199   }
 200
 201 }
 202
 203 void lmm_solve(lmm_system_t sys)
 204 {
 205   lmm_variable_t var = NULL;
 206   lmm_constraint_t cnst = NULL;
 207   lmm_element_t elem = NULL;
 208   xbt_swag_t cnst_list = NULL;
 209   xbt_swag_t var_list = NULL;
 210   xbt_swag_t elem_list = NULL;
 211   xbt_maxmin_float_t min_usage = -1;
 212
 213   /* Init */
 214   var_list = &(sys->variable_set);
 215   xbt_swag_foreach(var, var_list) {
 216     var->value = -1;
 217   }
 218
 219
 220   /* Compute Usage and store the variables that reach the maximum */
 221
 222   cnst_list = &(sys->active_constraint_set);
 223   xbt_swag_foreach(cnst, cnst_list) {
 224     /* INIT */
 225     elem_list = &(cnst->element_set);
 226     cnst->remaining = cnst->bound;
 227     cnst->usage = 0;
 228     xbt_swag_foreach(elem, elem_list) {
 229       cnst->usage += elem->value / elem->variable->weight;
 230       insert_active_elem_in_constraint(elem);
 231     }
 232
 233     /* Saturated constraints update */
 234     saturated_constraints_update(sys, cnst, &min_usage);
 235   }
 236
 237   saturated_variables_update(sys);
 238
 239   /* Saturated variables update */
 240
 241   do {
 242     /* Fix the variables that have to be */
 243     var_list = &(sys->saturated_variable_set);
 244
 245
 246     xbt_swag_foreach(var, var_list) {
 247       /* First check if some of these variables have reach their upper
 248          bound and update min_usage accordingly. */
 249       if ((var->bound > 0) && (var->bound / var->weight < min_usage)) {
 250         min_usage = var->bound / var->weight;
 251       }
 252     }
 253
 254
 255     while ((var = xbt_swag_getFirst(var_list))) {
 256       int i;
 257
 258       var->value = min_usage / var->weight;
 259
 260       /* Update usage */
 261
 262       for (i = 0; i < var->cnsts_number; i++) {
 263         elem = &var->cnsts[i];
 264         cnst = elem->constraint;
 265         cnst->remaining -= elem->value * var->value;
 266         cnst->usage -= elem->value / var->weight;
 267         remove_active_elem_in_constraint(elem);
 268       }
 269       xbt_swag_remove(var, var_list);
 270     }
 271
 272     /* Find out which variables reach the maximum */
 273     cnst_list = &(sys->active_constraint_set);
 274     min_usage = -1;
 275     xbt_swag_foreach(cnst, cnst_list) {
 276       saturated_constraints_update(sys, cnst, &min_usage);
 277     }
 278     saturated_variables_update(sys);
 279
 280   } while (xbt_swag_size(&(sys->saturated_variable_set)));
 281 }
 282
 283 /* Not a O(1) function */
 284
 285 void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
 286                 lmm_variable_t var, xbt_maxmin_float_t value)
 287 {
 288   int i;
 289   lmm_element_t elem = NULL;
 290
 291   for (i = 0; i < var->cnsts_number; i++)
 292     if (var->cnsts[i].constraint == cnst) {
 293       elem->value = value;
 294       return;
 295     }
 296 }
 297
 298 void lmm_update_variable_bound(lmm_variable_t var,
 299                                xbt_maxmin_float_t bound)
 300 {
 301   var->bound = bound;
 302 }
 303
 304 void lmm_update_variable_weight(lmm_variable_t var,
 305                                 xbt_maxmin_float_t weight)
 306 {
 307   var->weight = weight;
 308 }
 309
 310 void lmm_update_constraint_bound(lmm_constraint_t cnst,
 311                                  xbt_maxmin_float_t bound)
 312 {
 313   cnst->bound = bound;
 314 }
 315
 316 int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
 317 {
 318   return xbt_swag_belongs(cnst,&(sys->active_constraint_set));
 319 }
 320
 321
 322 /* void lmm_print(lmm_system_t sys) */
 323 /* { */
 324 /*   lmm_variable_t var = NULL; */
 325 /*   lmm_constraint_t cnst = NULL; */
 326 /*   lmm_element_t elem = NULL; */
 327 /*   xbt_swag_t cnst_list = NULL; */
 328 /*   xbt_swag_t var_list = NULL; */
 329 /*   xbt_swag_t elem_list = NULL; */
 330
 331 /*   var_list = &(sys->variable_set); */
 332 /*   xbt_swag_foreach(var, var_list) { */
 333 /*     printf("%s : {\n",var->id); */
 334 /*     printf("\t %s : {\n",var->id); */
 335 /*   } */
 336 /* } */