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",
  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 //if we modify the swag between calls, normal version may loop forever
 435 //this safe version ensures that we browse the swag elements only once
 436 lmm_variable_t lmm_get_var_from_cnst_safe(lmm_system_t /*sys*/,
 437                                      lmm_constraint_t cnst,
 438                                      lmm_element_t * elem,
 439                                      lmm_element_t * nextelem,
 440                                      int * numelem)
 441 {
 442   if (!(*elem)){
 443     *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->element_set));
 444     *numelem = xbt_swag_size(&(cnst->element_set))-1;
 445   }else{
 446     *elem = *nextelem;
 447     if(*numelem>0){
 448      (*numelem) --;
 449     }else
 450       return NULL;
 451   }
 452   if (*elem){
 453     *nextelem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->element_set.offset);
 454     return (*elem)->variable;
 455   }else
 456     return NULL;
 457 }
 458
 459 void *lmm_constraint_id(lmm_constraint_t cnst)
 460 {
 461   return cnst->id;
 462 }
 463
 464 void *lmm_variable_id(lmm_variable_t var)
 465 {
 466   return var->id;
 467 }
 468
 469 static XBT_INLINE void saturated_constraint_set_update(double usage,
 470                                                       int cnst_light_num,
 471                                                       dyn_light_t saturated_constraint_set,
 472                                                       double *min_usage)
 473 {
 474   xbt_assert(usage > 0,"Impossible");
 475
 476   if (*min_usage < 0 || *min_usage > usage) {
 477     *min_usage = usage;
 478     // XBT_HERE(" min_usage=%f (cnst->remaining / cnst->usage =%f)", *min_usage, usage);
 479     saturated_constraint_set->data[0] = cnst_light_num;
 480     saturated_constraint_set->pos = 1;
 481   } else if (*min_usage == usage) {
 482     if(saturated_constraint_set->pos == saturated_constraint_set->size) { // realloc the size
 483       saturated_constraint_set->size *= 2;
 484       saturated_constraint_set->data = (int*) xbt_realloc(saturated_constraint_set->data, (saturated_constraint_set->size) * sizeof(int));
 485     }
 486     saturated_constraint_set->data[saturated_constraint_set->pos] = cnst_light_num;
 487     saturated_constraint_set->pos++;
 488   }
 489 }
 490
 491 static XBT_INLINE void saturated_variable_set_update(
 492     s_lmm_constraint_light_t *cnst_light_tab,
 493     dyn_light_t saturated_constraint_set,
 494     lmm_system_t sys)
 495 {
 496   /* Add active variables (i.e. variables that need to be set) from the set of constraints to saturate (cnst_light_tab)*/
 497   lmm_constraint_light_t cnst = NULL;
 498   void *_elem;
 499   lmm_element_t elem = NULL;
 500   xbt_swag_t elem_list = NULL;
 501   int i;
 502   for(i = 0; i< saturated_constraint_set->pos; i++){
 503     cnst = &cnst_light_tab[saturated_constraint_set->data[i]];
 504     elem_list = &(cnst->cnst->active_element_set);
 505     xbt_swag_foreach(_elem, elem_list) {
 506       elem = (lmm_element_t)_elem;
 507       if (elem->variable->weight <= 0)
 508         break;
 509       if ((elem->value > 0))
 510         xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
 511     }
 512   }
 513 }
 514
 515 void lmm_print(lmm_system_t sys)
 516 {
 517   void *_cnst, *_elem, *_var;
 518   lmm_constraint_t cnst = NULL;
 519   lmm_element_t elem = NULL;
 520   lmm_variable_t var = NULL;
 521   xbt_swag_t cnst_list = NULL;
 522   xbt_swag_t var_list = NULL;
 523   xbt_swag_t elem_list = NULL;
 524   char print_buf[1024];
 525   char *trace_buf = (char*) xbt_malloc0(sizeof(char));
 526   double sum = 0.0;
 527
 528   /* Printing Objective */
 529   var_list = &(sys->variable_set);
 530   sprintf(print_buf, "MAX-MIN ( ");
 531   trace_buf = (char*)
 532       xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 533   strcat(trace_buf, print_buf);
 534   xbt_swag_foreach(_var, var_list) {
 535         var = (lmm_variable_t)_var;
 536     sprintf(print_buf, "'%d'(%f) ", var->id_int, var->weight);
 537     trace_buf = (char*)
 538         xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 539     strcat(trace_buf, print_buf);
 540   }
 541   sprintf(print_buf, ")");
 542   trace_buf = (char*)
 543       xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 544   strcat(trace_buf, print_buf);
 545   XBT_DEBUG("%20s", trace_buf);
 546   trace_buf[0] = '\000';
 547
 548   XBT_DEBUG("Constraints");
 549   /* Printing Constraints */
 550   cnst_list = &(sys->active_constraint_set);
 551   xbt_swag_foreach(_cnst, cnst_list) {
 552         cnst = (lmm_constraint_t)_cnst;
 553     sum = 0.0;
 554     elem_list = &(cnst->element_set);
 555     sprintf(print_buf, "\t");
 556     trace_buf = (char*)
 557         xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 558     strcat(trace_buf, print_buf);
 559     sprintf(print_buf, "%s(",(cnst->shared)?"":"max");
 560     trace_buf = (char*)
 561       xbt_realloc(trace_buf,
 562       strlen(trace_buf) + strlen(print_buf) + 1);
 563     strcat(trace_buf, print_buf);
 564     xbt_swag_foreach(_elem, elem_list) {
 565       elem = (lmm_element_t)_elem;
 566       sprintf(print_buf, "%f.'%d'(%f) %s ", elem->value,
 567               elem->variable->id_int, elem->variable->value,(cnst->shared)?"+":",");
 568       trace_buf = (char*)
 569           xbt_realloc(trace_buf,
 570                       strlen(trace_buf) + strlen(print_buf) + 1);
 571       strcat(trace_buf, print_buf);
 572       if(cnst->shared)
 573   sum += elem->value * elem->variable->value;
 574       else
 575   sum = MAX(sum,elem->value * elem->variable->value);
 576     }
 577     sprintf(print_buf, "0) <= %f ('%d')", cnst->bound, cnst->id_int);
 578     trace_buf = (char*)
 579         xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
 580     strcat(trace_buf, print_buf);
 581
 582     if (!cnst->shared) {
 583       sprintf(print_buf, " [MAX-Constraint]");
 584       trace_buf = (char*)
 585           xbt_realloc(trace_buf,
 586                       strlen(trace_buf) + strlen(print_buf) + 1);
 587       strcat(trace_buf, print_buf);
 588     }
 589     XBT_DEBUG("%s", trace_buf);
 590     trace_buf[0] = '\000';
 591     xbt_assert(!double_positive(sum - cnst->bound, cnst->bound*sg_maxmin_precision),
 592                 "Incorrect value (%f is not smaller than %f): %g",
 593                 sum, cnst->bound, sum - cnst->bound);
 594   }
 595
 596   XBT_DEBUG("Variables");
 597   /* Printing Result */
 598   xbt_swag_foreach(_var, var_list) {
 599         var = (lmm_variable_t)_var;
 600     if (var->bound > 0) {
 601       XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->weight, var->value,
 602              var->bound);
 603       xbt_assert(!double_positive(var->value - var->bound, var->bound*sg_maxmin_precision),
 604                   "Incorrect value (%f is not smaller than %f",
 605                   var->value, var->bound);
 606     } else {
 607       XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->weight, var->value);
 608     }
 609   }
 610
 611   free(trace_buf);
 612 }
 613
 614 void lmm_solve(lmm_system_t sys)
 615 {
 616   void *_var, *_cnst, *_cnst_next, *_elem;
 617   lmm_variable_t var = NULL;
 618   lmm_constraint_t cnst = NULL;
 619   lmm_element_t elem = NULL;
 620   xbt_swag_t cnst_list = NULL;
 621   xbt_swag_t var_list = NULL;
 622   xbt_swag_t elem_list = NULL;
 623   double min_usage = -1;
 624   double min_bound = -1;
 625
 626   if (!(sys->modified))
 627     return;
 628
 629   XBT_IN("(sys=%p)", sys);
 630
 631   /*
 632    * Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only constraints that changed are considered. Otherwise all constraints with active actions are considered.
 633    */
 634   cnst_list =
 635       sys->
 636       selective_update_active ? &(sys->modified_constraint_set) :
 637       &(sys->active_constraint_set);
 638
 639   XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
 640   /* Init: Only modified code portions: reset the value of active variables */
 641   xbt_swag_foreach(_cnst, cnst_list) {
 642         cnst = (lmm_constraint_t)_cnst;
 643     elem_list = &(cnst->element_set);
 644     //XBT_DEBUG("Variable set : %d", xbt_swag_size(elem_list));
 645     xbt_swag_foreach(_elem, elem_list) {
 646       var = ((lmm_element_t)_elem)->variable;
 647       if (var->weight <= 0.0)
 648         break;
 649       var->value = 0.0;
 650     }
 651   }
 652
 653   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));
 654   int cnst_light_num = 0;
 655   dyn_light_t saturated_constraint_set = xbt_new0(s_dyn_light_t,1);
 656   saturated_constraint_set->size = 5;
 657   saturated_constraint_set->data = xbt_new0(int, saturated_constraint_set->size);
 658
 659   xbt_swag_foreach_safe(_cnst, _cnst_next, cnst_list) {
 660         cnst = (lmm_constraint_t)_cnst;
 661     /* INIT: Collect constraints that actually need to be saturated (i.e remaining  and usage are strictly positive) into cnst_light_tab. */
 662     cnst->remaining = cnst->bound;
 663     if (!double_positive(cnst->remaining, cnst->bound*sg_maxmin_precision))
 664       continue;
 665     cnst->usage = 0;
 666     elem_list = &(cnst->element_set);
 667     xbt_swag_foreach(_elem, elem_list) {
 668       elem = (lmm_element_t)_elem;
 669       /* 0-weighted elements (ie, sleep actions) are at the end of the swag and we don't want to consider them */
 670       if (elem->variable->weight <= 0)
 671         break;
 672       if ((elem->value > 0)) {
 673         if (cnst->shared)
 674           cnst->usage += elem->value / elem->variable->weight;
 675         else if (cnst->usage < elem->value / elem->variable->weight)
 676           cnst->usage = elem->value / elem->variable->weight;
 677
 678         make_elem_active(elem);
 679         Action *action = static_cast<Action*>(elem->variable->id);
 680         if (sys->keep_track && !action->is_linked())
 681           sys->keep_track->push_back(*action);
 682       }
 683     }
 684     XBT_DEBUG("Constraint '%d' usage: %f remaining: %f ", cnst->id_int, cnst->usage, cnst->remaining);
 685     /* Saturated constraints update */
 686
 687     if(cnst->usage > 0) {
 688       cnst_light_tab[cnst_light_num].cnst = cnst;
 689       cnst->cnst_light = &(cnst_light_tab[cnst_light_num]);
 690       cnst_light_tab[cnst_light_num].remaining_over_usage = cnst->remaining / cnst->usage;
 691       saturated_constraint_set_update(cnst_light_tab[cnst_light_num].remaining_over_usage,
 692         cnst_light_num, saturated_constraint_set, &min_usage);
 693       xbt_assert(cnst->active_element_set.count>0, "There is no sense adding a constraint that has no active element!" );
 694       cnst_light_num++;
 695     }
 696   }
 697
 698   saturated_variable_set_update(  cnst_light_tab,
 699                                   saturated_constraint_set,
 700                                   sys);
 701
 702   /* Saturated variables update */
 703
 704   do {
 705     /* Fix the variables that have to be */
 706     var_list = &(sys->saturated_variable_set);
 707
 708     xbt_swag_foreach(_var, var_list) {
 709       var = (lmm_variable_t)_var;
 710       if (var->weight <= 0.0)
 711         DIE_IMPOSSIBLE;
 712       /* First check if some of these variables could reach their upper
 713          bound and update min_bound accordingly. */
 714       XBT_DEBUG
 715           ("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f",
 716            var->id_int, var->bound, var->weight, min_usage,
 717            var->bound * var->weight);
 718       if ((var->bound > 0) && (var->bound * var->weight < min_usage)) {
 719         if (min_bound < 0)
 720           min_bound = var->bound*var->weight;
 721         else
 722           min_bound = MIN(min_bound, (var->bound*var->weight));
 723         XBT_DEBUG("Updated min_bound=%f", min_bound);
 724       }
 725     }
 726
 727
 728     while ((var = (lmm_variable_t)xbt_swag_getFirst(var_list))) {
 729       int i;
 730
 731       if (min_bound < 0) {
 732         //If no variable could reach its bound, deal iteratively the constraints usage ( at worst one constraint is saturated at each cycle)
 733         var->value = min_usage / var->weight;
 734         XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
 735       } else {
 736         //If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
 737             if (double_equals(min_bound, var->bound*var->weight, sg_maxmin_precision)){
 738           var->value = var->bound;
 739           XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
 740         }
 741         else {
 742           // Variables which bound is different are not considered for this cycle, but they will be afterwards.
 743           XBT_DEBUG("Do not consider %p (%d) \n", var, var->id_int);
 744           xbt_swag_remove(var, var_list);
 745           continue;
 746         }
 747       }
 748       XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ",
 749              min_usage, var->id_int, var->weight, var->id_int, var->value);
 750
 751
 752       /* Update the usage of contraints where this variable is involved */
 753       for (i = 0; i < var->cnsts_number; i++) {
 754         elem = &var->cnsts[i];
 755         cnst = elem->constraint;
 756         if (cnst->shared) {
 757           //Remember: shared constraints require that sum(elem->value * var->value) < cnst->bound
 758           double_update(&(cnst->remaining),  elem->value * var->value, cnst->bound*sg_maxmin_precision);
 759           double_update(&(cnst->usage), elem->value / var->weight, sg_maxmin_precision);
 760           //If the constraint is saturated, remove it from the set of active constraints (light_tab)
 761           if(!double_positive(cnst->usage,sg_maxmin_precision) || !double_positive(cnst->remaining,cnst->bound*sg_maxmin_precision)) {
 762             if (cnst->cnst_light) {
 763               int index = (cnst->cnst_light-cnst_light_tab);
 764               XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p \t cnst_light_tab: %p usage: %f remaining: %f bound: %f  ",
 765                         index,cnst_light_num, cnst, cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining, cnst->bound);
 766               cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
 767               cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
 768               cnst_light_num--;
 769               cnst->cnst_light = NULL;
 770             }
 771           } else {
 772             cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
 773           }
 774           make_elem_inactive(elem);
 775         } else {
 776           //Remember: non-shared constraints only require that max(elem->value * var->value) < cnst->bound
 777           cnst->usage = 0.0;
 778           make_elem_inactive(elem);
 779           elem_list = &(cnst->element_set);
 780           xbt_swag_foreach(_elem, elem_list) {
 781                 elem = (lmm_element_t)_elem;
 782                 if (elem->variable->weight <= 0) break; //Found an inactive variable -> no more active variables
 783             if (elem->variable->value > 0) continue;
 784             if (elem->value > 0)
 785               cnst->usage = MAX(cnst->usage, elem->value / elem->variable->weight);
 786           }
 787           //If the constraint is saturated, remove it from the set of active constraints (light_tab)
 788           if(!double_positive(cnst->usage,sg_maxmin_precision) || !double_positive(cnst->remaining,cnst->bound*sg_maxmin_precision)) {
 789             if(cnst->cnst_light) {
 790               int index = (cnst->cnst_light-cnst_light_tab);
 791               XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p \t cnst_light_tab: %p usage: %f remaining: %f bound: %f  ",
 792                         index,cnst_light_num, cnst, cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining, cnst->bound);
 793               cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
 794               cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
 795               cnst_light_num--;
 796               cnst->cnst_light = NULL;
 797             }
 798           } else {
 799             cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
 800             xbt_assert(cnst->active_element_set.count>0, "Should not keep a maximum constraint that has no active element! You want to check the maxmin precision and possible rounding effects." );
 801           }
 802         }
 803       }
 804       xbt_swag_remove(var, var_list);
 805     }
 806
 807     /* Find out which variables reach the maximum */
 808     min_usage = -1;
 809     min_bound = -1;
 810     saturated_constraint_set->pos = 0;
 811     int pos;
 812     for(pos=0; pos<cnst_light_num; pos++){
 813       xbt_assert(cnst_light_tab[pos].cnst->active_element_set.count>0, "Cannot saturate more a constraint that has no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>) because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.", cnst_light_tab[pos].cnst->usage, sg_maxmin_precision, cnst_light_tab[pos-1].cnst->usage);
 814       saturated_constraint_set_update(
 815           cnst_light_tab[pos].remaining_over_usage,
 816           pos,
 817           saturated_constraint_set,
 818           &min_usage);
 819         }
 820
 821     saturated_variable_set_update(  cnst_light_tab,
 822                                     saturated_constraint_set,
 823                                     sys);
 824
 825   } while (cnst_light_num > 0);
 826
 827   sys->modified = 0;
 828   if (sys->selective_update_active)
 829     lmm_remove_all_modified_set(sys);
 830
 831   if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
 832     lmm_print(sys);
 833   }
 834
 835   xbt_free(saturated_constraint_set->data);
 836   xbt_free(saturated_constraint_set);
 837   xbt_free(cnst_light_tab);
 838   XBT_OUT();
 839 }
 840
 841 /* Not a O(1) function */
 842
 843 void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
 844                 lmm_variable_t var, double value)
 845 {
 846   int i;
 847
 848   for (i = 0; i < var->cnsts_number; i++)
 849     if (var->cnsts[i].constraint == cnst) {
 850       var->cnsts[i].value = value;
 851       sys->modified = 1;
 852       lmm_update_modified_set(sys, cnst);
 853       return;
 854     }
 855 }
 856
 857 /** \brief Attribute the value bound to var->bound.
 858  *
 859  *  \param sys the lmm_system_t
 860  *  \param var the lmm_variable_t
 861  *  \param bound the new bound to associate with var
 862  *
 863  *  Makes var->bound equal to bound. Whenever this function is called
 864  *  a change is  signed in the system. To
 865  *  avoid false system changing detection it is a good idea to test
 866  *  (bound != 0) before calling it.
 867  *
 868  */
 869 void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var,
 870                                double bound)
 871 {
 872   sys->modified = 1;
 873   var->bound = bound;
 874
 875   if (var->cnsts_number)
 876     lmm_update_modified_set(sys, var->cnsts[0].constraint);
 877 }
 878
 879
 880 void lmm_update_variable_weight(lmm_system_t sys, lmm_variable_t var,
 881                                 double weight)
 882 {
 883   int i;
 884   lmm_element_t elem;
 885
 886   if (weight == var->weight)
 887     return;
 888   XBT_IN("(sys=%p, var=%p, weight=%f)", sys, var, weight);
 889   sys->modified = 1;
 890   var->weight = weight;
 891   xbt_swag_remove(var, &(sys->variable_set));
 892   if (weight)
 893     xbt_swag_insert_at_head(var, &(sys->variable_set));
 894   else
 895     xbt_swag_insert_at_tail(var, &(sys->variable_set));
 896
 897   for (i = 0; i < var->cnsts_number; i++) {
 898     elem = &var->cnsts[i];
 899     xbt_swag_remove(elem, &(elem->constraint->element_set));
 900     if (weight)
 901       xbt_swag_insert_at_head(elem, &(elem->constraint->element_set));
 902     else
 903       xbt_swag_insert_at_tail(elem, &(elem->constraint->element_set));
 904
 905     if (i == 0)
 906       lmm_update_modified_set(sys, elem->constraint);
 907   }
 908   if (!weight)
 909     var->value = 0.0;
 910
 911   XBT_OUT();
 912 }
 913
 914 double lmm_get_variable_weight(lmm_variable_t var)
 915 {
 916   return var->weight;
 917 }
 918
 919 void lmm_update_constraint_bound(lmm_system_t sys,
 920                                             lmm_constraint_t cnst,
 921                                             double bound)
 922 {
 923   sys->modified = 1;
 924   lmm_update_modified_set(sys, cnst);
 925   cnst->bound = bound;
 926 }
 927
 928 int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
 929 {
 930   return xbt_swag_belongs(cnst, &(sys->active_constraint_set));
 931 }
 932
 933 XBT_INLINE lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t
 934                                                             sys)
 935 {
 936   return (lmm_constraint_t)xbt_swag_getFirst(&(sys->active_constraint_set));
 937 }
 938
 939 XBT_INLINE lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t
 940                                                            sys,
 941                                                            lmm_constraint_t
 942                                                            cnst)
 943 {
 944   return (lmm_constraint_t)xbt_swag_getNext(cnst, (sys->active_constraint_set).offset);
 945 }
 946
 947 #ifdef HAVE_LATENCY_BOUND_TRACKING
 948 XBT_INLINE int lmm_is_variable_limited_by_latency(lmm_variable_t var)
 949 {
 950   return (double_equals(var->bound, var->value, var->bound*sg_maxmin_precision));
 951 }
 952 #endif
 953
 954
 955 /** \brief Update the constraint set propagating recursively to
 956  *  other constraints so the system should not be entirely computed.
 957  *
 958  *  \param sys the lmm_system_t
 959  *  \param cnst the lmm_constraint_t affected by the change
 960  *
 961  *  A recursive algorithm to optimize the system recalculation selecting only
 962  *  constraints that have changed. Each constraint change is propagated
 963  *  to the list of constraints for each variable.
 964  */
 965 static void lmm_update_modified_set_rec(lmm_system_t sys,
 966                                         lmm_constraint_t cnst)
 967 {
 968   void* _elem;
 969
 970   xbt_swag_foreach(_elem, &cnst->element_set) {
 971     lmm_variable_t var = ((lmm_element_t)_elem)->variable;
 972     s_lmm_element_t *cnsts = var->cnsts;
 973     int i;
 974     for (i = 0; var->visited != sys->visited_counter
 975              && i < var->cnsts_number ; i++) {
 976       if (cnsts[i].constraint != cnst
 977           && !xbt_swag_belongs(cnsts[i].constraint,
 978                                &sys->modified_constraint_set)) {
 979         xbt_swag_insert(cnsts[i].constraint, &sys->modified_constraint_set);
 980         lmm_update_modified_set_rec(sys, cnsts[i].constraint);
 981       }
 982     }
 983     var->visited = sys->visited_counter;
 984   }
 985 }
 986
 987 static void lmm_update_modified_set(lmm_system_t sys,
 988                                     lmm_constraint_t cnst)
 989 {
 990   /* nothing to do if selective update isn't active */
 991   if (sys->selective_update_active
 992       && !xbt_swag_belongs(cnst, &sys->modified_constraint_set)) {
 993     xbt_swag_insert(cnst, &sys->modified_constraint_set);
 994     lmm_update_modified_set_rec(sys, cnst);
 995   }
 996 }
 997
 998 /** \brief Remove all constraints of the modified_constraint_set.
 999  *
1000  *  \param sys the lmm_system_t
1001  */
1002 static void lmm_remove_all_modified_set(lmm_system_t sys)
1003 {
1004   if (++sys->visited_counter == 1) {
1005     /* the counter wrapped around, reset each variable->visited */
1006         void *_var;
1007     xbt_swag_foreach(_var, &sys->variable_set)
1008       ((lmm_variable_t)_var)->visited = 0;
1009   }
1010   xbt_swag_reset(&sys->modified_constraint_set);
1011 }
1012
1013 /**
1014  *  Returns total resource load
1015  *
1016  *  \param cnst the lmm_constraint_t associated to the resource
1017  *
1018  */
1019 double lmm_constraint_get_usage(lmm_constraint_t cnst) {
1020    double usage = 0.0;
1021    xbt_swag_t elem_list = &(cnst->element_set);
1022    void *_elem;
1023    lmm_element_t elem = NULL;
1024
1025    xbt_swag_foreach(_elem, elem_list) {
1026          elem = (lmm_element_t)_elem;
1027      /* 0-weighted elements (ie, sleep actions) are at the end of the swag and we don't want to consider them */
1028      if (elem->variable->weight <= 0)
1029        break;
1030      if ((elem->value > 0)) {
1031        if (cnst->shared)
1032          usage += elem->value * elem->variable->value;
1033        else if (usage < elem->value * elem->variable->value)
1034          usage = elem->value * elem->variable->value;
1035      }
1036    }
1037   return usage;
1038 }
1039
1040