src/surf/maxmin.cpp

   1 /* Copyright (c) 2004-2014. The SimGrid Team.
   2  * All rights reserved.                                                     */
   3
   4 /* This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the license (GNU LGPL) which comes with this package. */
   6
   7 #include "xbt/sysdep.h"
   8 #include "xbt/log.h"
   9 #include "xbt/mallocator.h"
  10 #include "maxmin_private.hpp"
  11 #include <stdlib.h>
  12 #include <stdio.h>              /* sprintf */
  13 #include <math.h>
  14 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_maxmin, surf,
  15                                 "Logging specific to SURF (maxmin)");
  16
  17 typedef struct s_dyn_light {
  18   int *data;
  19   int pos;
  20   int size;
  21 } s_dyn_light_t, *dyn_light_t;
  22
  23 XBT_EXPORT_NO_IMPORT(double) sg_maxmin_precision = 0.00001;
  24 XBT_EXPORT_NO_IMPORT(double) sg_surf_precision   = 0.00001;
  25
  26 static void *lmm_variable_mallocator_new_f(void);
  27 static void lmm_variable_mallocator_free_f(void *var);
  28 #define lmm_variable_mallocator_reset_f ((void_f_pvoid_t)NULL)
  29 static void lmm_update_modified_set(lmm_system_t sys,
  30                                     lmm_constraint_t cnst);
  31 static void lmm_remove_all_modified_set(lmm_system_t sys);
  32 static int Global_debug_id = 1;
  33 static int Global_const_debug_id = 1;
  34
  35 static void lmm_var_free(lmm_system_t sys, lmm_variable_t var);
  36 static XBT_INLINE void lmm_cnst_free(lmm_system_t sys,
  37                                      lmm_constraint_t cnst);
  38
  39 lmm_system_t lmm_system_new(int selective_update)
  40 {
  41   lmm_system_t l = NULL;
  42   s_lmm_variable_t var;
  43   s_lmm_constraint_t cnst;
  44
  45   l = xbt_new0(s_lmm_system_t, 1);
  46
  47   l->modified = 0;
  48   l->selective_update_active = selective_update;
  49   l->visited_counter = 1;
  50
  51   XBT_DEBUG("Setting selective_update_active flag to %d\n",
  52          l->selective_update_active);
  53
  54   xbt_swag_init(&(l->variable_set),
  55                 xbt_swag_offset(var, variable_set_hookup));
  56   xbt_swag_init(&(l->constraint_set),
  57                 xbt_swag_offset(cnst, constraint_set_hookup));
  58
  59   xbt_swag_init(&(l->active_constraint_set),
  60                 xbt_swag_offset(cnst, active_constraint_set_hookup));
  61
  62   xbt_swag_init(&(l->modified_constraint_set),
  63                 xbt_swag_offset(cnst, modified_constraint_set_hookup));
  64   xbt_swag_init(&(l->saturated_variable_set),
  65                 xbt_swag_offset(var, saturated_variable_set_hookup));
  66   xbt_swag_init(&(l->saturated_constraint_set),
  67                 xbt_swag_offset(cnst, saturated_constraint_set_hookup));
  68
  69   l->variable_mallocator = xbt_mallocator_new(65536,
  70                                               lmm_variable_mallocator_new_f,
  71                                               lmm_variable_mallocator_free_f,
  72                                               lmm_variable_mallocator_reset_f);
  73
  74   return l;
  75 }
  76
  77 void lmm_system_free(lmm_system_t sys)
  78 {
  79   lmm_variable_t var = NULL;
  80   lmm_constraint_t cnst = NULL;
  81
  82   while ((var = (lmm_variable_t) extract_variable(sys))) {
  83     XBT_WARN
  84         ("Variable %p (%d) still in LMM system when freing it: this may be a bug",
  85          var, var->id_int);
  86     lmm_var_free(sys, var);
  87   }
  88
  89   while ((cnst = (lmm_constraint_t) extract_constraint(sys)))
  90     lmm_cnst_free(sys, cnst);
  91
  92   xbt_mallocator_free(sys->variable_mallocator);
  93   free(sys);
  94 }
  95
  96 static XBT_INLINE void lmm_variable_disable(lmm_system_t sys, lmm_variable_t var)
  97 {
  98   int i;
  99   int n;
 100
 101   lmm_element_t elem = NULL;
 102
 103   XBT_IN("(sys=%p, var=%p)", sys, var);
 104   sys->modified = 1;
 105
 106   n = 0;
 107   for (i = 0; i < var->cnsts_number; i++) {
 108     elem = &var->cnsts[i];
 109     xbt_swag_remove(elem, &(elem->constraint->element_set));
 110     xbt_swag_remove(elem, &(elem->constraint->active_element_set));
 111     if (!xbt_swag_size(&(elem->constraint->element_set)))
 112       make_constraint_inactive(sys, elem->constraint);
 113     else {
 114       if (n < i)
 115         var->cnsts[n].constraint = elem->constraint;
 116       n++;
 117     }
 118   }
 119   if (n) {
 120     var->cnsts_number = n;
 121     lmm_update_modified_set(sys, var->cnsts[0].constraint);
 122   }
 123
 124   var->cnsts_number = 0;
 125   XBT_OUT();
 126 }
 127
 128 static void lmm_var_free(lmm_system_t sys, lmm_variable_t var)
 129 {
 130
 131   lmm_variable_disable(sys, var);
 132   xbt_mallocator_release(sys->variable_mallocator, var);
 133 }
 134
 135 static XBT_INLINE void lmm_cnst_free(lmm_system_t sys,
 136                                      lmm_constraint_t cnst)
 137 {
 138 /*   xbt_assert(xbt_swag_size(&(cnst->element_set)), */
 139 /*         "This list should be empty!"); */
 140   make_constraint_inactive(sys, cnst);
 141   free(cnst);
 142 }
 143
 144 lmm_constraint_t lmm_constraint_new(lmm_system_t sys, void *id,
 145                                     double bound_value)
 146 {
 147   lmm_constraint_t cnst = NULL;
 148   s_lmm_element_t elem;
 149
 150   cnst = xbt_new0(s_lmm_constraint_t, 1);
 151   cnst->id = id;
 152   cnst->id_int = Global_const_debug_id++;
 153   xbt_swag_init(&(cnst->element_set),
 154                 xbt_swag_offset(elem, element_set_hookup));
 155   xbt_swag_init(&(cnst->active_element_set),
 156                 xbt_swag_offset(elem, active_element_set_hookup));
 157
 158   cnst->bound = bound_value;
 159   cnst->usage = 0;
 160   cnst->shared = 1;
 161   insert_constraint(sys, cnst);
 162
 163   return cnst;
 164 }
 165
 166 void lmm_constraint_shared(lmm_constraint_t cnst)
 167 {
 168   cnst->shared = 0;
 169 }
 170
 171 int lmm_constraint_is_shared(lmm_constraint_t cnst)
 172 {
 173   return (cnst->shared);
 174 }
 175
 176 XBT_INLINE void lmm_constraint_free(lmm_system_t sys,
 177                                     lmm_constraint_t cnst)
 178 {
 179   remove_constraint(sys, cnst);
 180   lmm_cnst_free(sys, cnst);
 181 }
 182
 183 static void *lmm_variable_mallocator_new_f(void)
 184 {
 185   lmm_variable_t var = xbt_new(s_lmm_variable_t, 1);
 186   var->cnsts = NULL; /* will be created by realloc */
 187   return var;
 188 }
 189
 190 static void lmm_variable_mallocator_free_f(void *var)
 191 {
 192   xbt_free(((lmm_variable_t) var)->cnsts);
 193   xbt_free(var);
 194 }
 195
 196 lmm_variable_t lmm_variable_new(lmm_system_t sys, void *id,
 197                                 double weight,
 198                                 double bound, int number_of_constraints)
 199 {
 200   lmm_variable_t var = NULL;
 201   int i;
 202
 203   XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)",
 204           sys, id, weight, bound, number_of_constraints);
 205
 206   var = (lmm_variable_t) xbt_mallocator_get(sys->variable_mallocator);
 207   var->id = id;
 208   var->id_int = Global_debug_id++;
 209   var->cnsts = (s_lmm_element_t *) xbt_realloc(var->cnsts, number_of_constraints * sizeof(s_lmm_element_t));
 210   for (i = 0; i < number_of_constraints; i++) {
 211     var->cnsts[i].element_set_hookup.next = NULL;
 212     var->cnsts[i].element_set_hookup.prev = NULL;
 213     var->cnsts[i].active_element_set_hookup.next = NULL;
 214     var->cnsts[i].active_element_set_hookup.prev = NULL;
 215     var->cnsts[i].constraint = NULL;
 216     var->cnsts[i].variable = NULL;
 217     var->cnsts[i].value = 0.0;
 218   }
 219   var->cnsts_size = number_of_constraints;
 220   var->cnsts_number = 0;
 221   var->weight = weight;
 222   var->bound = bound;
 223   var->value = 0.0;
 224   var->visited = sys->visited_counter - 1;
 225   var->mu = 0.0;
 226   var->new_mu = 0.0;
 227   var->func_f = func_f_def;
 228   var->func_fp = func_fp_def;
 229   var->func_fpi = func_fpi_def;
 230
 231   var->variable_set_hookup.next = NULL;
 232   var->variable_set_hookup.prev = NULL;
 233   var->saturated_variable_set_hookup.next = NULL;
 234   var->saturated_variable_set_hookup.prev = NULL;
 235
 236   if (weight)
 237     xbt_swag_insert_at_head(var, &(sys->variable_set));
 238   else
 239     xbt_swag_insert_at_tail(var, &(sys->variable_set));
 240
 241   XBT_OUT(" returns %p", var);
 242   return var;
 243 }
 244
 245 void lmm_variable_free(lmm_system_t sys, lmm_variable_t var)
 246 {
 247   remove_variable(sys, var);
 248   lmm_var_free(sys, var);
 249 }
 250
 251 double lmm_variable_getvalue(lmm_variable_t var)
 252 {
 253   return (var->value);
 254 }
 255
 256 double lmm_variable_getbound(lmm_variable_t var)
 257 {
 258   return (var->bound);
 259 }
 260
 261 /* Replace the content of elem_a with elem_b. The content of elem_b is cleared. */
 262 static void renew_elem_entry(lmm_element_t elem_a, lmm_element_t elem_b)
 263 {
 264     elem_a->constraint = elem_b->constraint;
 265     elem_a->variable   = elem_b->variable;
 266     elem_a->value      = elem_b->value;
 267
 268     /* If elem_b is in the element_set swag, register the new element to the swag. */
 269     if (xbt_swag_remove(elem_b, &(elem_b->constraint->element_set))) {
 270       if (elem_a->variable->weight)
 271         xbt_swag_insert_at_head(elem_a, &(elem_a->constraint->element_set));
 272       else
 273         xbt_swag_insert_at_tail(elem_a, &(elem_a->constraint->element_set));
 274     }
 275
 276     if (xbt_swag_remove(elem_b, &(elem_b->constraint->active_element_set))) {
 277       if (elem_a->variable->weight)
 278         xbt_swag_insert_at_head(elem_a, &(elem_a->constraint->active_element_set));
 279       else
 280         xbt_swag_insert_at_tail(elem_a, &(elem_a->constraint->active_element_set));
 281     }
 282
 283     elem_b->constraint = NULL;
 284     elem_b->variable   = NULL;
 285     elem_b->value      = 0;
 286 }
 287
 288 void lmm_shrink(lmm_system_t sys, lmm_constraint_t cnst,
 289                 lmm_variable_t var)
 290 {
 291   lmm_element_t elem = NULL;
 292   int found = 0;
 293
 294   int i;
 295   for (i = 0; i < var->cnsts_number; i++) {
 296     elem = &(var->cnsts[i]);
 297     if (elem->constraint == cnst) {
 298       found = 1;
 299       break;
 300     }
 301   }
 302
 303   if (!found) {
 304     XBT_DEBUG("cnst %p is not found in var %p", cnst, var);
 305     return;
 306   }
 307
 308   sys->modified = 1;
 309
 310   XBT_DEBUG("remove elem(value %f, cnst %p, var %p) in var %p",
 311       elem->value, elem->constraint, elem->variable, var);
 312
 313
 314
 315   /* We are going to change the constraint object and the variable object.
 316    * Propagate this change to other objects. Calling here (not after
 317    * modification) is correct? */
 318   lmm_update_modified_set(sys, cnst);
 319   lmm_update_modified_set(sys, var->cnsts[0].constraint); // will look up element_set of this constraint, and then each var in the element_set, and each var->cnsts[i].
 320
 321
 322
 323   /* now var->cnsts[i] is not necessary any more */
 324
 325   xbt_swag_remove(elem, &(elem->constraint->element_set));
 326   xbt_swag_remove(elem, &(elem->constraint->active_element_set));
 327   elem->constraint = NULL;
 328   elem->variable = NULL;
 329   elem->value = 0;
 330
 331
 332
 333   /* We do not want to have an empty element entry before the last entry. So,
 334    * plug up the hole with the last one. */
 335   if (i < var->cnsts_number - 1)
 336     renew_elem_entry(&var->cnsts[i], &var->cnsts[var->cnsts_number - 1]);
 337
 338   var->cnsts_number -= 1;
 339
 340
 341   if (xbt_swag_size(&(cnst->element_set)) == 0)
 342     make_constraint_inactive(sys, cnst);
 343 }
 344
 345 void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
 346                 lmm_variable_t var, double value)
 347 {
 348   lmm_element_t elem = NULL;
 349
 350   sys->modified = 1;
 351
 352   xbt_assert(var->cnsts_number < var->cnsts_size, "Too much constraints");
 353
 354   elem = &(var->cnsts[var->cnsts_number++]);
 355
 356   elem->value = value;
 357   elem->constraint = cnst;
 358   elem->variable = var;
 359
 360   if (var->weight)
 361     xbt_swag_insert_at_head(elem, &(elem->constraint->element_set));
 362   else
 363     xbt_swag_insert_at_tail(elem, &(elem->constraint->element_set));
 364   if(!sys->selective_update_active) {
 365     make_constraint_active(sys, cnst);
 366   } else if(elem->value>0 || var->weight >0) {
 367     make_constraint_active(sys, cnst);
 368     lmm_update_modified_set(sys, cnst);
 369     if (var->cnsts_number > 1)
 370       lmm_update_modified_set(sys, var->cnsts[0].constraint);
 371   }
 372 }
 373
 374 void lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst,
 375                     lmm_variable_t var, double value)
 376 {
 377   int i;
 378   sys->modified = 1;
 379
 380   for (i = 0; i < var->cnsts_number; i++)
 381     if (var->cnsts[i].constraint == cnst)
 382       break;
 383
 384   if (i < var->cnsts_number) {
 385     if (cnst->shared)
 386       var->cnsts[i].value += value;
 387     else
 388       var->cnsts[i].value = MAX(var->cnsts[i].value, value);
 389     lmm_update_modified_set(sys, cnst);
 390   } else
 391     lmm_expand(sys, cnst, var, value);
 392 }
 393
 394 lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t /*sys*/,
 395                                                   lmm_variable_t var,
 396                                                   int num)
 397 {
 398   if (num < var->cnsts_number)
 399     return (var->cnsts[num].constraint);
 400   else
 401     return NULL;
 402 }
 403
 404 double lmm_get_cnst_weight_from_var(lmm_system_t /*sys*/,
 405                                                          lmm_variable_t var,
 406                                                          int num)
 407 {
 408   if (num < var->cnsts_number)
 409     return (var->cnsts[num].value);
 410   else
 411     return 0.0;
 412 }
 413
 414 int lmm_get_number_of_cnst_from_var(lmm_system_t /*sys*/,
 415                                                lmm_variable_t var)
 416 {
 417   return (var->cnsts_number);
 418 }
 419
 420 lmm_variable_t lmm_get_var_from_cnst(lmm_system_t /*sys*/,
 421                                      lmm_constraint_t cnst,
 422                                      lmm_element_t * elem)
 423 {
 424   if (!(*elem))
 425     *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->element_set));
 426   else
 427     *elem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->element_set.offset);
 428   if (*elem)
 429     return (*elem)->variable;
 430   else
 431     return NULL;
 432 }
 433
 434 void *lmm_constraint_id(lmm_constraint_t cnst)
 435 {
 436   return cnst->id;
 437 }
 438
 439 void *lmm_variable_id(lmm_variable_t var)
 440 {
 441   return var->id;
 442 }
 443
 444 static XBT_INLINE void saturated_constraint_set_update(double usage,
 445                                                       int cnst_light_num,
 446                                                       dyn_light_t saturated_constraint_set,
 447                                                       double *min_usage)
 448 {
 449   xbt_assert(usage > 0,"Impossible");
 450
 451   if (*min_usage < 0 || *min_usage > usage) {
 452     *min_usage = usage;
 453     // XBT_HERE(" min_usage=%f (cnst->remaining / cnst->usage =%f)", *min_usage, usage);
 454     saturated_constraint_set->data[0] = cnst_light_num;
 455     saturated_constraint_set->pos = 1;
 456   } else if (*min_usage == usage) {
 457     if(saturated_constraint_set->pos == saturated_constraint_set->size) { // realloc the size
 458       saturated_constraint_set->size *= 2;
 459       saturated_constraint_set->data = (int*) xbt_realloc(saturated_constraint_set->data, (saturated_constraint_set->size) * sizeof(int));
 460     }
 461     saturated_constraint_set->data[saturated_constraint_set->pos] = cnst_light_num;
 462     saturated_constraint_set->pos++;
 463   }
 464 }
 465
 466 static XBT_INLINE void saturated_variable_set_update(
 467     s_lmm_constraint_light_t *cnst_light_tab,
 468     dyn_light_t saturated_constraint_set,
 469     lmm_system_t sys)
 470 {
 471   lmm_constraint_light_t cnst = NULL;
 472   void *_elem;
 473   lmm_element_t elem = NULL;
 474   xbt_swag_t elem_list = NULL;
 475   int i;
 476   for(i = 0; i< saturated_constraint_set->pos; i++){
 477     cnst = &cnst_light_tab[saturated_constraint_set->data[i]];
 478     elem_list = &(cnst->cnst->active_element_set);
 479     xbt_swag_foreach(_elem, elem_list) {
 480       elem = (lmm_element_t)_elem;
 481       if (elem->variable->weight <= 0)
 482         break;
 483       if ((elem->value > 0))
 484         xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
 485     }
 486   }
 487 }
 488
 489 void lmm_print(lmm_system_t sys)
 490 {
 491   void *_cnst, *_elem, *_var;
 492   lmm_constraint_t cnst = NULL;
 493   lmm_element_t elem = NULL;
 494   lmm_variable_t var = NULL;
 495   xbt_swag_t cnst_list = NULL;
 496   xbt_swag_t var_list = NULL;
 497   xbt_swag_t elem_list = NULL;
 498   char print_buf[1024];
 499   char *trace_buf = (char*) xbt_malloc0(sizeof(char));
 500   double sum = 0.0;
 501
 502   /* Printing Objective */
 503   var_list = &(sys->variable_set);
 504   sprintf(print_buf, "MAX-MIN ( ");
 505   trace_buf = (char*)
 506       xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 507   strcat(trace_buf, print_buf);
 508   xbt_swag_foreach(_var, var_list) {
 509         var = (lmm_variable_t)_var;
 510     sprintf(print_buf, "'%d'(%f) ", var->id_int, var->weight);
 511     trace_buf = (char*)
 512         xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 513     strcat(trace_buf, print_buf);
 514   }
 515   sprintf(print_buf, ")");
 516   trace_buf = (char*)
 517       xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 518   strcat(trace_buf, print_buf);
 519   XBT_DEBUG("%20s", trace_buf);
 520   trace_buf[0] = '\000';
 521
 522   XBT_DEBUG("Constraints");
 523   /* Printing Constraints */
 524   cnst_list = &(sys->active_constraint_set);
 525   xbt_swag_foreach(_cnst, cnst_list) {
 526         cnst = (lmm_constraint_t)_cnst;
 527     sum = 0.0;
 528     elem_list = &(cnst->element_set);
 529     sprintf(print_buf, "\t");
 530     trace_buf = (char*)
 531         xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 532     strcat(trace_buf, print_buf);
 533     sprintf(print_buf, "%s(",(cnst->shared)?"":"max");
 534     trace_buf = (char*)
 535       xbt_realloc(trace_buf,
 536       strlen(trace_buf) + strlen(print_buf) + 1);
 537     strcat(trace_buf, print_buf);
 538     xbt_swag_foreach(_elem, elem_list) {
 539       elem = (lmm_element_t)_elem;
 540       sprintf(print_buf, "%f.'%d'(%f) %s ", elem->value,
 541               elem->variable->id_int, elem->variable->value,(cnst->shared)?"+":",");
 542       trace_buf = (char*)
 543           xbt_realloc(trace_buf,
 544                       strlen(trace_buf) + strlen(print_buf) + 1);
 545       strcat(trace_buf, print_buf);
 546       if(cnst->shared)
 547   sum += elem->value * elem->variable->value;
 548       else
 549   sum = MAX(sum,elem->value * elem->variable->value);
 550     }
 551     sprintf(print_buf, "0) <= %f ('%d')", cnst->bound, cnst->id_int);
 552     trace_buf = (char*)
 553         xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 554     strcat(trace_buf, print_buf);
 555
 556     if (!cnst->shared) {
 557       sprintf(print_buf, " [MAX-Constraint]");
 558       trace_buf = (char*)
 559           xbt_realloc(trace_buf,
 560                       strlen(trace_buf) + strlen(print_buf) + 1);
 561       strcat(trace_buf, print_buf);
 562     }
 563     XBT_DEBUG("%s", trace_buf);
 564     trace_buf[0] = '\000';
 565     xbt_assert(!double_positive(sum - cnst->bound, sg_maxmin_precision),
 566                 "Incorrect value (%f is not smaller than %f): %g",
 567                 sum, cnst->bound, sum - cnst->bound);
 568   }
 569
 570   XBT_DEBUG("Variables");
 571   /* Printing Result */
 572   xbt_swag_foreach(_var, var_list) {
 573         var = (lmm_variable_t)_var;
 574     if (var->bound > 0) {
 575       XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->weight, var->value,
 576              var->bound);
 577       xbt_assert(!double_positive(var->value - var->bound, sg_maxmin_precision),
 578                   "Incorrect value (%f is not smaller than %f",
 579                   var->value, var->bound);
 580     } else {
 581       XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->weight, var->value);
 582     }
 583   }
 584
 585   free(trace_buf);
 586 }
 587
 588 void lmm_solve(lmm_system_t sys)
 589 {
 590   void *_var, *_cnst, *_cnst_next, *_elem;
 591   lmm_variable_t var = NULL;
 592   lmm_constraint_t cnst = NULL;
 593   lmm_element_t elem = NULL;
 594   xbt_swag_t cnst_list = NULL;
 595   xbt_swag_t var_list = NULL;
 596   xbt_swag_t elem_list = NULL;
 597   double min_usage = -1;
 598   double min_bound = -1;
 599
 600   if (!(sys->modified))
 601     return;
 602
 603   XBT_IN("(sys=%p)", sys);
 604
 605   /*
 606    * Compute Usage and store the variables that reach the maximum.
 607    */
 608   cnst_list =
 609       sys->
 610       selective_update_active ? &(sys->modified_constraint_set) :
 611       &(sys->active_constraint_set);
 612
 613   XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
 614   /* Init: Only modified code portions */
 615   xbt_swag_foreach(_cnst, cnst_list) {
 616         cnst = (lmm_constraint_t)_cnst;
 617     elem_list = &(cnst->element_set);
 618     //XBT_DEBUG("Variable set : %d", xbt_swag_size(elem_list));
 619     xbt_swag_foreach(_elem, elem_list) {
 620       var = ((lmm_element_t)_elem)->variable;
 621       if (var->weight <= 0.0)
 622         break;
 623       var->value = 0.0;
 624     }
 625   }
 626
 627   s_lmm_constraint_light_t *cnst_light_tab = (s_lmm_constraint_light_t *)xbt_malloc0(xbt_swag_size(cnst_list)*sizeof(s_lmm_constraint_light_t));
 628   int cnst_light_num = 0;
 629   dyn_light_t saturated_constraint_set = xbt_new0(s_dyn_light_t,1);
 630   saturated_constraint_set->size = 5;
 631   saturated_constraint_set->data = xbt_new0(int, saturated_constraint_set->size);
 632
 633   xbt_swag_foreach_safe(_cnst, _cnst_next, cnst_list) {
 634         cnst = (lmm_constraint_t)_cnst;
 635     /* INIT */
 636     cnst->remaining = cnst->bound;
 637     if (cnst->remaining == 0)
 638       continue;
 639     cnst->usage = 0;
 640     elem_list = &(cnst->element_set);
 641     xbt_swag_foreach(_elem, elem_list) {
 642       elem = (lmm_element_t)_elem;
 643       /* 0-weighted elements (ie, sleep actions) are at the end of the swag and we don't want to consider them */
 644       if (elem->variable->weight <= 0)
 645         break;
 646       if ((elem->value > 0)) {
 647         if (cnst->shared)
 648           cnst->usage += elem->value / elem->variable->weight;
 649         else if (cnst->usage < elem->value / elem->variable->weight)
 650           cnst->usage = elem->value / elem->variable->weight;
 651
 652         make_elem_active(elem);
 653         ActionPtr action = static_cast<ActionPtr>(elem->variable->id);
 654         if (sys->keep_track && !action->is_linked())
 655           sys->keep_track->push_back(*action);
 656       }
 657     }
 658     XBT_DEBUG("Constraint Usage '%d' : %f", cnst->id_int, cnst->usage);
 659     /* Saturated constraints update */
 660
 661     if(cnst->usage > 0) {
 662       cnst_light_tab[cnst_light_num].cnst = cnst;
 663       cnst->cnst_light = &(cnst_light_tab[cnst_light_num]);
 664       cnst_light_tab[cnst_light_num].remaining_over_usage = cnst->remaining / cnst->usage;
 665       saturated_constraint_set_update(cnst_light_tab[cnst_light_num].remaining_over_usage,
 666         cnst_light_num, saturated_constraint_set, &min_usage);
 667       cnst_light_num++;
 668     }
 669   }
 670
 671   saturated_variable_set_update(  cnst_light_tab,
 672                                   saturated_constraint_set,
 673                                   sys);
 674
 675   /* Saturated variables update */
 676
 677   do {
 678     /* Fix the variables that have to be */
 679     var_list = &(sys->saturated_variable_set);
 680
 681     xbt_swag_foreach(_var, var_list) {
 682       var = (lmm_variable_t)_var;
 683       if (var->weight <= 0.0)
 684         DIE_IMPOSSIBLE;
 685       /* First check if some of these variables have reach their upper
 686          bound and update min_usage accordingly. */
 687       XBT_DEBUG
 688           ("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f",
 689            var->id_int, var->bound, var->weight, min_usage,
 690            var->bound * var->weight);
 691       if ((var->bound > 0) && (var->bound * var->weight < min_usage)) {
 692         if (min_bound < 0)
 693           min_bound = var->bound;
 694         else
 695           min_bound = MIN(min_bound, var->bound);
 696         XBT_DEBUG("Updated min_bound=%f", min_bound);
 697       }
 698     }
 699
 700
 701     while ((var = (lmm_variable_t)xbt_swag_getFirst(var_list))) {
 702       int i;
 703
 704       if (min_bound < 0) {
 705         var->value = min_usage / var->weight;
 706         XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
 707       } else {
 708         if (min_bound == var->bound) {
 709           var->value = var->bound;
 710           XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
 711         }
 712         else {
 713           XBT_DEBUG("Do not consider %p (%d)\n", var, var->id_int);
 714           xbt_swag_remove(var, var_list);
 715           continue;
 716         }
 717       }
 718       XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ",
 719              min_usage, var->id_int, var->weight, var->id_int, var->value);
 720
 721
 722       /* Update usage */
 723
 724       for (i = 0; i < var->cnsts_number; i++) {
 725         elem = &var->cnsts[i];
 726         cnst = elem->constraint;
 727         if (cnst->shared) {
 728           double_update(&(cnst->remaining), elem->value * var->value, sg_maxmin_precision);
 729           double_update(&(cnst->usage), elem->value / var->weight, sg_maxmin_precision);
 730           if(cnst->usage<=0 || cnst->remaining<=0) {
 731             if (cnst->cnst_light) {
 732               int index = (cnst->cnst_light-cnst_light_tab);
 733               XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p \t cnst_light_tab: %p ",
 734                   index,cnst_light_num, cnst, cnst->cnst_light, cnst_light_tab);
 735               cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
 736               cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
 737               cnst_light_num--;
 738               cnst->cnst_light = NULL;
 739             }
 740           } else {
 741             cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
 742           }
 743           make_elem_inactive(elem);
 744         } else {
 745           cnst->usage = 0.0;
 746           make_elem_inactive(elem);
 747           elem_list = &(cnst->element_set);
 748           xbt_swag_foreach(_elem, elem_list) {
 749                 elem = (lmm_element_t)_elem;
 750             if (elem->variable->weight <= 0) break;
 751             if (elem->variable->value > 0) continue;
 752             if (elem->value > 0)
 753               cnst->usage = MAX(cnst->usage, elem->value / elem->variable->weight);
 754           }
 755           if (cnst->usage<=0 || cnst->remaining<=0) {
 756             if(cnst->cnst_light) {
 757               int index = (cnst->cnst_light-cnst_light_tab);
 758               XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p \t cnst_light_tab: %p ",
 759                   index,cnst_light_num, cnst, cnst->cnst_light, cnst_light_tab);
 760               cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
 761               cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
 762               cnst_light_num--;
 763               cnst->cnst_light = NULL;
 764             }
 765           } else {
 766             cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
 767           }
 768         }
 769       }
 770       xbt_swag_remove(var, var_list);
 771     }
 772
 773     /* Find out which variables reach the maximum */
 774     min_usage = -1;
 775     min_bound = -1;
 776     saturated_constraint_set->pos = 0;
 777     int pos;
 778     for(pos=0; pos<cnst_light_num; pos++)
 779       saturated_constraint_set_update(
 780           cnst_light_tab[pos].remaining_over_usage,
 781           pos,
 782           saturated_constraint_set,
 783           &min_usage);
 784
 785     saturated_variable_set_update(  cnst_light_tab,
 786                                     saturated_constraint_set,
 787                                     sys);
 788
 789   } while (cnst_light_num > 0);
 790
 791   sys->modified = 0;
 792   if (sys->selective_update_active)
 793     lmm_remove_all_modified_set(sys);
 794
 795   if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
 796     lmm_print(sys);
 797   }
 798
 799   xbt_free(saturated_constraint_set->data);
 800   xbt_free(saturated_constraint_set);
 801   xbt_free(cnst_light_tab);
 802   XBT_OUT();
 803 }
 804
 805 /* Not a O(1) function */
 806
 807 void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
 808                 lmm_variable_t var, double value)
 809 {
 810   int i;
 811
 812   for (i = 0; i < var->cnsts_number; i++)
 813     if (var->cnsts[i].constraint == cnst) {
 814       var->cnsts[i].value = value;
 815       sys->modified = 1;
 816       lmm_update_modified_set(sys, cnst);
 817       return;
 818     }
 819 }
 820
 821 /** \brief Attribute the value bound to var->bound.
 822  *
 823  *  \param sys the lmm_system_t
 824  *  \param var the lmm_variable_t
 825  *  \param bound the new bound to associate with var
 826  *
 827  *  Makes var->bound equal to bound. Whenever this function is called
 828  *  a change is  signed in the system. To
 829  *  avoid false system changing detection it is a good idea to test
 830  *  (bound != 0) before calling it.
 831  *
 832  */
 833 void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var,
 834                                double bound)
 835 {
 836   sys->modified = 1;
 837   var->bound = bound;
 838
 839   if (var->cnsts_number)
 840     lmm_update_modified_set(sys, var->cnsts[0].constraint);
 841 }
 842
 843
 844 void lmm_update_variable_weight(lmm_system_t sys, lmm_variable_t var,
 845                                 double weight)
 846 {
 847   int i;
 848   lmm_element_t elem;
 849
 850   if (weight == var->weight)
 851     return;
 852   XBT_IN("(sys=%p, var=%p, weight=%f)", sys, var, weight);
 853   sys->modified = 1;
 854   var->weight = weight;
 855   xbt_swag_remove(var, &(sys->variable_set));
 856   if (weight)
 857     xbt_swag_insert_at_head(var, &(sys->variable_set));
 858   else
 859     xbt_swag_insert_at_tail(var, &(sys->variable_set));
 860
 861   for (i = 0; i < var->cnsts_number; i++) {
 862     elem = &var->cnsts[i];
 863     xbt_swag_remove(elem, &(elem->constraint->element_set));
 864     if (weight)
 865       xbt_swag_insert_at_head(elem, &(elem->constraint->element_set));
 866     else
 867       xbt_swag_insert_at_tail(elem, &(elem->constraint->element_set));
 868
 869     if (i == 0)
 870       lmm_update_modified_set(sys, elem->constraint);
 871   }
 872   if (!weight)
 873     var->value = 0.0;
 874
 875   XBT_OUT();
 876 }
 877
 878 double lmm_get_variable_weight(lmm_variable_t var)
 879 {
 880   return var->weight;
 881 }
 882
 883 void lmm_update_constraint_bound(lmm_system_t sys,
 884                                             lmm_constraint_t cnst,
 885                                             double bound)
 886 {
 887   sys->modified = 1;
 888   lmm_update_modified_set(sys, cnst);
 889   cnst->bound = bound;
 890 }
 891
 892 int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
 893 {
 894   return xbt_swag_belongs(cnst, &(sys->active_constraint_set));
 895 }
 896
 897 XBT_INLINE lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t
 898                                                             sys)
 899 {
 900   return (lmm_constraint_t)xbt_swag_getFirst(&(sys->active_constraint_set));
 901 }
 902
 903 XBT_INLINE lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t
 904                                                            sys,
 905                                                            lmm_constraint_t
 906                                                            cnst)
 907 {
 908   return (lmm_constraint_t)xbt_swag_getNext(cnst, (sys->active_constraint_set).offset);
 909 }
 910
 911 #ifdef HAVE_LATENCY_BOUND_TRACKING
 912 XBT_INLINE int lmm_is_variable_limited_by_latency(lmm_variable_t var)
 913 {
 914   return (double_equals(var->bound, var->value, sg_maxmin_precision));
 915 }
 916 #endif
 917
 918
 919 /** \brief Update the constraint set propagating recursively to
 920  *  other constraints so the system should not be entirely computed.
 921  *
 922  *  \param sys the lmm_system_t
 923  *  \param cnst the lmm_constraint_t affected by the change
 924  *
 925  *  A recursive algorithm to optimize the system recalculation selecting only
 926  *  constraints that have changed. Each constraint change is propagated
 927  *  to the list of constraints for each variable.
 928  */
 929 static void lmm_update_modified_set_rec(lmm_system_t sys,
 930                                         lmm_constraint_t cnst)
 931 {
 932   void* _elem;
 933
 934   xbt_swag_foreach(_elem, &cnst->element_set) {
 935     lmm_variable_t var = ((lmm_element_t)_elem)->variable;
 936     s_lmm_element_t *cnsts = var->cnsts;
 937     int i;
 938     for (i = 0; var->visited != sys->visited_counter
 939              && i < var->cnsts_number ; i++) {
 940       if (cnsts[i].constraint != cnst
 941           && !xbt_swag_belongs(cnsts[i].constraint,
 942                                &sys->modified_constraint_set)) {
 943         xbt_swag_insert(cnsts[i].constraint, &sys->modified_constraint_set);
 944         lmm_update_modified_set_rec(sys, cnsts[i].constraint);
 945       }
 946     }
 947     var->visited = sys->visited_counter;
 948   }
 949 }
 950
 951 static void lmm_update_modified_set(lmm_system_t sys,
 952                                     lmm_constraint_t cnst)
 953 {
 954   /* nothing to do if selective update isn't active */
 955   if (sys->selective_update_active
 956       && !xbt_swag_belongs(cnst, &sys->modified_constraint_set)) {
 957     xbt_swag_insert(cnst, &sys->modified_constraint_set);
 958     lmm_update_modified_set_rec(sys, cnst);
 959   }
 960 }
 961
 962 /** \brief Remove all constraints of the modified_constraint_set.
 963  *
 964  *  \param sys the lmm_system_t
 965  */
 966 static void lmm_remove_all_modified_set(lmm_system_t sys)
 967 {
 968   if (++sys->visited_counter == 1) {
 969     /* the counter wrapped around, reset each variable->visited */
 970         void *_var;
 971     xbt_swag_foreach(_var, &sys->variable_set)
 972       ((lmm_variable_t)_var)->visited = 0;
 973   }
 974   xbt_swag_reset(&sys->modified_constraint_set);
 975 }
 976
 977 /**
 978  *  Returns total resource load
 979  *
 980  *  \param cnst the lmm_constraint_t associated to the resource
 981  *
 982  */
 983 double lmm_constraint_get_usage(lmm_constraint_t cnst) {
 984    double usage = 0.0;
 985    xbt_swag_t elem_list = &(cnst->element_set);
 986    void *_elem;
 987    lmm_element_t elem = NULL;
 988
 989    xbt_swag_foreach(_elem, elem_list) {
 990          elem = (lmm_element_t)_elem;
 991      /* 0-weighted elements (ie, sleep actions) are at the end of the swag and we don't want to consider them */
 992      if (elem->variable->weight <= 0)
 993        break;
 994      if ((elem->value > 0)) {
 995        if (cnst->shared)
 996          usage += elem->value * elem->variable->value;
 997        else if (usage < elem->value * elem->variable->value)
 998          usage = elem->value * elem->variable->value;
 999      }
1000    }
1001   return usage;
1002 }
1003
1004