1 /* Copyright (c) 2004-2017. The SimGrid Team. All rights reserved. */
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. */
6 /* \file callbacks.h */
8 #include "maxmin_private.hpp"
9 #include "xbt/backtrace.hpp"
11 #include "xbt/mallocator.h"
12 #include "xbt/sysdep.h"
20 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_maxmin, surf, "Logging specific to SURF (maxmin)");
22 typedef std::vector<int> dyn_light_t;
24 double sg_maxmin_precision = 0.00001; /* Change this with --cfg=maxmin/precision:VALUE */
25 double sg_surf_precision = 0.00001; /* Change this with --cfg=surf/precision:VALUE */
26 int sg_concurrency_limit = -1; /* Change this with --cfg=maxmin/concurrency-limit:VALUE */
28 static int Global_debug_id = 1;
29 int s_lmm_constraint_t::Global_debug_id = 1;
31 static int lmm_can_enable_var(lmm_variable_t var);
32 static int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var);
34 static inline int lmm_element_concurrency(lmm_element_t elem)
36 //Ignore element with weight less than one (e.g. cross-traffic)
37 return (elem->consumption_weight >= 1) ? 1 : 0;
38 //There are other alternatives, but they will change the behaviour of the model..
39 //So do not use it unless you want to make a new model.
40 //If you do, remember to change the variables concurrency share to reflect it.
41 //Potential examples are:
42 //return (elem->weight>0)?1:0;//Include element as soon as weight is non-zero
43 //return (int)ceil(elem->weight);//Include element as the rounded-up integer value of the element weight
46 static inline void lmm_decrease_concurrency(lmm_element_t elem)
48 xbt_assert(elem->constraint->concurrency_current>=lmm_element_concurrency(elem));
49 elem->constraint->concurrency_current-=lmm_element_concurrency(elem);
52 static inline void lmm_increase_concurrency(lmm_element_t elem)
54 elem->constraint->concurrency_current+= lmm_element_concurrency(elem);
56 lmm_constraint_t cnstr=elem->constraint;
58 if(cnstr->concurrency_current > cnstr->concurrency_maximum)
59 cnstr->concurrency_maximum= cnstr->concurrency_current;
61 xbt_assert(cnstr->get_concurrency_limit() < 0 || cnstr->concurrency_current <= cnstr->get_concurrency_limit(),
62 "Concurrency limit overflow!");
65 void s_lmm_system_t::check_concurrency()
67 // These checks are very expensive, so do them only if we want to debug SURF LMM
68 if (not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug))
72 xbt_swag_foreach(cnstIt, &constraint_set)
74 lmm_constraint_t cnst = (lmm_constraint_t)cnstIt;
77 xbt_swag_foreach(elemIt, &(cnst->enabled_element_set))
79 lmm_element_t elem = (lmm_element_t)elemIt;
80 xbt_assert(elem->variable->sharing_weight > 0);
81 concurrency += lmm_element_concurrency(elem);
84 xbt_swag_foreach(elemIt, &(cnst->disabled_element_set))
86 lmm_element_t elem = (lmm_element_t)elemIt;
87 // We should have staged variables only if concurrency is reached in some constraint
88 xbt_assert(cnst->get_concurrency_limit() < 0 || elem->variable->staged_weight == 0 ||
89 lmm_cnstrs_min_concurrency_slack(elem->variable) < elem->variable->concurrency_share,
90 "should not have staged variable!");
93 xbt_assert(cnst->get_concurrency_limit() < 0 || cnst->get_concurrency_limit() >= concurrency,
94 "concurrency check failed!");
95 xbt_assert(cnst->concurrency_current == concurrency, "concurrency_current is out-of-date!");
98 // Check that for each variable, all corresponding elements are in the same state (i.e. same element sets)
100 xbt_swag_foreach(varIt, &variable_set)
102 lmm_variable_t var = (lmm_variable_t)varIt;
104 if (var->cnsts.empty())
107 lmm_element_t elem = &var->cnsts[0];
108 int belong_to_enabled = xbt_swag_belongs(elem, &(elem->constraint->enabled_element_set));
109 int belong_to_disabled = xbt_swag_belongs(elem, &(elem->constraint->disabled_element_set));
110 int belong_to_active = xbt_swag_belongs(elem, &(elem->constraint->active_element_set));
112 for (s_lmm_element_t const& elem : var->cnsts) {
113 xbt_assert(belong_to_enabled == xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)),
114 "Variable inconsistency (1): enabled_element_set");
115 xbt_assert(belong_to_disabled == xbt_swag_belongs(&elem, &(elem.constraint->disabled_element_set)),
116 "Variable inconsistency (2): disabled_element_set");
117 xbt_assert(belong_to_active == xbt_swag_belongs(&elem, &(elem.constraint->active_element_set)),
118 "Variable inconsistency (3): active_element_set");
123 void s_lmm_system_t::var_free(lmm_variable_t var)
125 XBT_IN("(sys=%p, var=%p)", this, var);
128 // TODOLATER Can do better than that by leaving only the variable in only one enabled_element_set, call
129 // update_modified_set, and then remove it..
130 if (not var->cnsts.empty())
131 update_modified_set(var->cnsts[0].constraint);
133 for (s_lmm_element_t& elem : var->cnsts) {
134 if (var->sharing_weight > 0)
135 lmm_decrease_concurrency(&elem);
136 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
137 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
138 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
139 int nelements = xbt_swag_size(&(elem.constraint->enabled_element_set)) +
140 xbt_swag_size(&(elem.constraint->disabled_element_set));
142 make_constraint_inactive(elem.constraint);
144 on_disabled_var(elem.constraint);
151 xbt_mallocator_release(variable_mallocator, var);
155 s_lmm_system_t::s_lmm_system_t(bool selective_update)
157 s_lmm_variable_t var;
158 s_lmm_constraint_t cnst;
161 selective_update_active = selective_update;
164 XBT_DEBUG("Setting selective_update_active flag to %d", selective_update_active);
166 xbt_swag_init(&variable_set, xbt_swag_offset(var, variable_set_hookup));
167 xbt_swag_init(&constraint_set, xbt_swag_offset(cnst, constraint_set_hookup));
169 xbt_swag_init(&active_constraint_set, xbt_swag_offset(cnst, active_constraint_set_hookup));
171 xbt_swag_init(&modified_constraint_set, xbt_swag_offset(cnst, modified_constraint_set_hookup));
172 xbt_swag_init(&saturated_variable_set, xbt_swag_offset(var, saturated_variable_set_hookup));
173 xbt_swag_init(&saturated_constraint_set, xbt_swag_offset(cnst, saturated_constraint_set_hookup));
175 keep_track = nullptr;
176 variable_mallocator = xbt_mallocator_new(65536, s_lmm_system_t::variable_mallocator_new_f,
177 s_lmm_system_t::variable_mallocator_free_f, nullptr);
178 solve_fun = &lmm_solve;
181 s_lmm_system_t::~s_lmm_system_t()
184 lmm_constraint_t cnst;
186 while ((var = extract_variable())) {
187 auto demangled = simgrid::xbt::demangle(typeid(*var->id).name());
188 XBT_WARN("Probable bug: a %s variable (#%d) not removed before the LMM system destruction.", demangled.get(),
192 while ((cnst = extract_constraint()))
195 xbt_mallocator_free(variable_mallocator);
198 void s_lmm_system_t::cnst_free(lmm_constraint_t cnst)
200 make_constraint_inactive(cnst);
204 s_lmm_constraint_t::s_lmm_constraint_t(void* id_value, double bound_value)
206 s_lmm_element_t elem;
209 id_int = Global_debug_id++;
210 xbt_swag_init(&enabled_element_set, xbt_swag_offset(elem, enabled_element_set_hookup));
211 xbt_swag_init(&disabled_element_set, xbt_swag_offset(elem, disabled_element_set_hookup));
212 xbt_swag_init(&active_element_set, xbt_swag_offset(elem, active_element_set_hookup));
217 concurrency_limit = sg_concurrency_limit;
218 concurrency_current = 0;
219 concurrency_maximum = 0;
220 sharing_policy = 1; /* FIXME: don't hardcode the value */
224 cnst_light = nullptr;
227 lmm_constraint_t s_lmm_system_t::constraint_new(void* id, double bound_value)
229 lmm_constraint_t cnst = new s_lmm_constraint_t(id, bound_value);
230 insert_constraint(cnst);
234 void* s_lmm_system_t::variable_mallocator_new_f()
236 return new s_lmm_variable_t;
239 void s_lmm_system_t::variable_mallocator_free_f(void* var)
241 delete static_cast<lmm_variable_t>(var);
244 lmm_variable_t s_lmm_system_t::variable_new(simgrid::surf::Action* id, double sharing_weight, double bound,
245 int number_of_constraints)
247 XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)", this, id, sharing_weight, bound, number_of_constraints);
249 lmm_variable_t var = (lmm_variable_t)xbt_mallocator_get(variable_mallocator);
251 var->id_int = Global_debug_id++;
252 var->cnsts.reserve(number_of_constraints);
253 var->sharing_weight = sharing_weight;
254 var->staged_weight = 0.0;
256 var->concurrency_share = 1;
258 var->visited = visited_counter - 1;
261 var->func_f = func_f_def;
262 var->func_fp = func_fp_def;
263 var->func_fpi = func_fpi_def;
265 var->variable_set_hookup.next = nullptr;
266 var->variable_set_hookup.prev = nullptr;
267 var->saturated_variable_set_hookup.next = nullptr;
268 var->saturated_variable_set_hookup.prev = nullptr;
271 xbt_swag_insert_at_head(var, &variable_set);
273 xbt_swag_insert_at_tail(var, &variable_set);
275 XBT_OUT(" returns %p", var);
279 void s_lmm_system_t::variable_free(lmm_variable_t var)
281 remove_variable(var);
285 double lmm_variable_getvalue(lmm_variable_t var)
290 void lmm_variable_concurrency_share_set(lmm_variable_t var, short int concurrency_share)
292 var->concurrency_share=concurrency_share;
295 double lmm_variable_getbound(lmm_variable_t var)
300 void s_lmm_system_t::expand(lmm_constraint_t cnst, lmm_variable_t var, double consumption_weight)
304 //Check if this variable already has an active element in this constraint
305 //If it does, substract it from the required slack
306 int current_share = 0;
307 if(var->concurrency_share>1){
308 for (s_lmm_element_t& elem : var->cnsts) {
309 if (elem.constraint == cnst && xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)))
310 current_share += lmm_element_concurrency(&elem);
314 //Check if we need to disable the variable
315 if (var->sharing_weight > 0 && var->concurrency_share - current_share > cnst->get_concurrency_slack()) {
316 double weight = var->sharing_weight;
318 for (s_lmm_element_t const& elem : var->cnsts)
319 on_disabled_var(elem.constraint);
320 consumption_weight = 0;
321 var->staged_weight=weight;
322 xbt_assert(not var->sharing_weight);
325 xbt_assert(var->cnsts.size() < var->cnsts.capacity(), "Too much constraints");
327 var->cnsts.resize(var->cnsts.size() + 1);
328 s_lmm_element_t& elem = var->cnsts.back();
330 elem.consumption_weight = consumption_weight;
331 elem.constraint = cnst;
334 if (var->sharing_weight) {
335 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
336 lmm_increase_concurrency(&elem);
338 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
340 if (not selective_update_active) {
341 make_constraint_active(cnst);
342 } else if (elem.consumption_weight > 0 || var->sharing_weight > 0) {
343 make_constraint_active(cnst);
344 update_modified_set(cnst);
345 //TODOLATER: Why do we need this second call?
346 if (var->cnsts.size() > 1)
347 update_modified_set(var->cnsts[0].constraint);
353 void s_lmm_system_t::expand_add(lmm_constraint_t cnst, lmm_variable_t var, double value)
359 //BEWARE: In case you have multiple elements in one constraint, this will always add value to the first element.
360 auto elem_it = std::find_if(begin(var->cnsts), end(var->cnsts),
361 [&cnst](s_lmm_element_t const& x) { return x.constraint == cnst; });
362 if (elem_it != end(var->cnsts)) {
363 s_lmm_element_t& elem = *elem_it;
364 if (var->sharing_weight)
365 lmm_decrease_concurrency(&elem);
367 if (cnst->sharing_policy)
368 elem.consumption_weight += value;
370 elem.consumption_weight = std::max(elem.consumption_weight, value);
372 //We need to check that increasing value of the element does not cross the concurrency limit
373 if (var->sharing_weight) {
374 if (cnst->get_concurrency_slack() < lmm_element_concurrency(&elem)) {
375 double weight = var->sharing_weight;
377 for (s_lmm_element_t const& elem2 : var->cnsts)
378 on_disabled_var(elem2.constraint);
379 var->staged_weight=weight;
380 xbt_assert(not var->sharing_weight);
382 lmm_increase_concurrency(&elem);
384 update_modified_set(cnst);
386 expand(cnst, var, value);
391 lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
393 if (num < var->cnsts.size())
394 return (var->cnsts[num].constraint);
399 double lmm_get_cnst_weight_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
401 if (num < var->cnsts.size())
402 return (var->cnsts[num].consumption_weight);
407 int lmm_get_number_of_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var)
409 return (var->cnsts.size());
412 lmm_variable_t s_lmm_constraint_t::get_variable(lmm_element_t* elem) const
414 if (*elem == nullptr) {
415 // That is the first call, pick the first element among enabled_element_set (or disabled_element_set if
416 // enabled_element_set is empty)
417 *elem = (lmm_element_t)xbt_swag_getFirst(&enabled_element_set);
418 if (*elem == nullptr)
419 *elem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
421 //elem is not null, so we carry on
422 if (xbt_swag_belongs(*elem, &enabled_element_set)) {
423 //Look at enabled_element_set, and jump to disabled_element_set when finished
424 *elem = (lmm_element_t)xbt_swag_getNext(*elem, enabled_element_set.offset);
425 if (*elem == nullptr)
426 *elem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
428 *elem = (lmm_element_t)xbt_swag_getNext(*elem, disabled_element_set.offset);
432 return (*elem)->variable;
437 //if we modify the swag between calls, normal version may loop forever
438 //this safe version ensures that we browse the swag elements only once
439 lmm_variable_t s_lmm_constraint_t::get_variable_safe(lmm_element_t* elem, lmm_element_t* nextelem, int* numelem) const
441 if (*elem == nullptr) {
442 *elem = (lmm_element_t)xbt_swag_getFirst(&enabled_element_set);
443 *numelem = xbt_swag_size(&enabled_element_set) + xbt_swag_size(&disabled_element_set) - 1;
444 if (*elem == nullptr)
445 *elem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
454 //elem is not null, so we carry on
455 if (xbt_swag_belongs(*elem, &enabled_element_set)) {
456 //Look at enabled_element_set, and jump to disabled_element_set when finished
457 *nextelem = (lmm_element_t)xbt_swag_getNext(*elem, enabled_element_set.offset);
458 if (*nextelem == nullptr)
459 *nextelem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
461 *nextelem = (lmm_element_t)xbt_swag_getNext(*elem, disabled_element_set.offset);
463 return (*elem)->variable;
468 void *lmm_variable_id(lmm_variable_t var)
473 static inline void saturated_constraint_set_update(double usage, int cnst_light_num,
474 dyn_light_t& saturated_constraint_set, double* min_usage)
476 xbt_assert(usage > 0,"Impossible");
478 if (*min_usage < 0 || *min_usage > usage) {
480 XBT_HERE(" min_usage=%f (cnst->remaining / cnst->usage =%f)", *min_usage, usage);
481 saturated_constraint_set.assign(1, cnst_light_num);
482 } else if (*min_usage == usage) {
483 saturated_constraint_set.emplace_back(cnst_light_num);
487 static inline void saturated_variable_set_update(s_lmm_constraint_light_t* cnst_light_tab,
488 const dyn_light_t& saturated_constraint_set, lmm_system_t sys)
490 /* Add active variables (i.e. variables that need to be set) from the set of constraints to saturate (cnst_light_tab)*/
491 for (int const& saturated_cnst : saturated_constraint_set) {
492 lmm_constraint_light_t cnst = &cnst_light_tab[saturated_cnst];
494 xbt_swag_t elem_list = &(cnst->cnst->active_element_set);
495 xbt_swag_foreach(_elem, elem_list) {
496 lmm_element_t elem = (lmm_element_t)_elem;
497 //Visiting active_element_set, so, by construction, should never get a zero weight, correct?
498 xbt_assert(elem->variable->sharing_weight > 0);
499 if (elem->consumption_weight > 0)
500 xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
505 void s_lmm_system_t::print()
507 std::string buf = std::string("MAX-MIN ( ");
510 /* Printing Objective */
511 xbt_swag_t var_list = &variable_set;
512 xbt_swag_foreach(_var, var_list) {
513 lmm_variable_t var = (lmm_variable_t)_var;
514 buf = buf + "'" + std::to_string(var->id_int) + "'(" + std::to_string(var->sharing_weight) + ") ";
517 XBT_DEBUG("%20s", buf.c_str());
520 XBT_DEBUG("Constraints");
521 /* Printing Constraints */
523 xbt_swag_t cnst_list = &active_constraint_set;
524 xbt_swag_foreach(_cnst, cnst_list) {
525 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
527 //Show the enabled variables
529 xbt_swag_t elem_list = &(cnst->enabled_element_set);
531 buf += ((cnst->sharing_policy) ? "(" : "max(");
532 xbt_swag_foreach(_elem, elem_list) {
533 lmm_element_t elem = (lmm_element_t)_elem;
534 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
535 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
536 if(cnst->sharing_policy)
537 sum += elem->consumption_weight * elem->variable->value;
539 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
541 //TODO: Adding disabled elements only for test compatibility, but do we really want them to be printed?
542 elem_list = &(cnst->disabled_element_set);
543 xbt_swag_foreach(_elem, elem_list) {
544 lmm_element_t elem = (lmm_element_t)_elem;
545 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
546 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
547 if(cnst->sharing_policy)
548 sum += elem->consumption_weight * elem->variable->value;
550 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
553 buf = buf + "0) <= " + std::to_string(cnst->bound) + " ('" + std::to_string(cnst->id_int) + "')";
555 if (not cnst->sharing_policy) {
556 buf += " [MAX-Constraint]";
558 XBT_DEBUG("%s", buf.c_str());
560 xbt_assert(not double_positive(sum - cnst->bound, cnst->bound * sg_maxmin_precision),
561 "Incorrect value (%f is not smaller than %f): %g", sum, cnst->bound, sum - cnst->bound);
564 XBT_DEBUG("Variables");
565 /* Printing Result */
566 xbt_swag_foreach(_var, var_list) {
567 lmm_variable_t var = (lmm_variable_t)_var;
568 if (var->bound > 0) {
569 XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->sharing_weight, var->value, var->bound);
570 xbt_assert(not double_positive(var->value - var->bound, var->bound * sg_maxmin_precision),
571 "Incorrect value (%f is not smaller than %f", var->value, var->bound);
573 XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->sharing_weight, var->value);
578 void s_lmm_system_t::solve()
583 double min_usage = -1;
584 double min_bound = -1;
589 XBT_IN("(sys=%p)", this);
591 /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only constraints
592 * that changed are considered. Otherwise all constraints with active actions are considered.
594 xbt_swag_t cnst_list = selective_update_active ? &modified_constraint_set : &active_constraint_set;
596 XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
597 /* Init: Only modified code portions: reset the value of active variables */
598 xbt_swag_foreach(_cnst, cnst_list) {
599 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
600 xbt_swag_t elem_list = &(cnst->enabled_element_set);
601 xbt_swag_foreach(_elem, elem_list) {
602 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
603 xbt_assert(var->sharing_weight > 0.0);
608 s_lmm_constraint_light_t* cnst_light_tab = new s_lmm_constraint_light_t[xbt_swag_size(cnst_list)]();
609 int cnst_light_num = 0;
610 dyn_light_t saturated_constraint_set;
612 xbt_swag_foreach_safe(_cnst, _cnst_next, cnst_list) {
613 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
614 /* INIT: Collect constraints that actually need to be saturated (i.e remaining and usage are strictly positive)
615 * into cnst_light_tab. */
616 cnst->remaining = cnst->bound;
617 if (not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision))
620 xbt_swag_t elem_list = &(cnst->enabled_element_set);
621 xbt_swag_foreach(_elem, elem_list) {
622 lmm_element_t elem = (lmm_element_t)_elem;
623 xbt_assert(elem->variable->sharing_weight > 0);
624 if (elem->consumption_weight > 0) {
625 if (cnst->sharing_policy)
626 cnst->usage += elem->consumption_weight / elem->variable->sharing_weight;
627 else if (cnst->usage < elem->consumption_weight / elem->variable->sharing_weight)
628 cnst->usage = elem->consumption_weight / elem->variable->sharing_weight;
630 make_elem_active(elem);
631 simgrid::surf::Action *action = static_cast<simgrid::surf::Action*>(elem->variable->id);
632 if (keep_track && not action->is_linked())
633 keep_track->push_back(*action);
636 XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst->id_int, cnst->usage,
637 cnst->remaining, cnst->concurrency_current, cnst->concurrency_maximum, cnst->get_concurrency_limit());
638 /* Saturated constraints update */
640 if(cnst->usage > 0) {
641 cnst_light_tab[cnst_light_num].cnst = cnst;
642 cnst->cnst_light = &(cnst_light_tab[cnst_light_num]);
643 cnst_light_tab[cnst_light_num].remaining_over_usage = cnst->remaining / cnst->usage;
644 saturated_constraint_set_update(cnst_light_tab[cnst_light_num].remaining_over_usage,
645 cnst_light_num, saturated_constraint_set, &min_usage);
646 xbt_assert(cnst->active_element_set.count>0, "There is no sense adding a constraint that has no active element!");
651 saturated_variable_set_update(cnst_light_tab, saturated_constraint_set, this);
653 /* Saturated variables update */
655 /* Fix the variables that have to be */
656 xbt_swag_t var_list = &saturated_variable_set;
658 lmm_variable_t var = nullptr;
659 xbt_swag_foreach(_var, var_list) {
660 var = (lmm_variable_t)_var;
661 if (var->sharing_weight <= 0.0)
663 /* First check if some of these variables could reach their upper bound and update min_bound accordingly. */
664 XBT_DEBUG("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f", var->id_int,
665 var->bound, var->sharing_weight, min_usage, var->bound * var->sharing_weight);
666 if ((var->bound > 0) && (var->bound * var->sharing_weight < min_usage)) {
668 min_bound = var->bound * var->sharing_weight;
670 min_bound = std::min(min_bound, (var->bound * var->sharing_weight));
671 XBT_DEBUG("Updated min_bound=%f", min_bound);
675 while ((var = (lmm_variable_t)xbt_swag_getFirst(var_list))) {
677 //If no variable could reach its bound, deal iteratively the constraints usage ( at worst one constraint is
678 // saturated at each cycle)
679 var->value = min_usage / var->sharing_weight;
680 XBT_DEBUG("Setting var (%d) value to %f\n", var->id_int, var->value);
682 //If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
683 if (double_equals(min_bound, var->bound * var->sharing_weight, sg_maxmin_precision)) {
684 var->value = var->bound;
685 XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
687 // Variables which bound is different are not considered for this cycle, but they will be afterwards.
688 XBT_DEBUG("Do not consider %p (%d) \n", var, var->id_int);
689 xbt_swag_remove(var, var_list);
693 XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ", min_usage, var->id_int, var->sharing_weight,
694 var->id_int, var->value);
696 /* Update the usage of contraints where this variable is involved */
697 for (s_lmm_element_t& elem : var->cnsts) {
698 lmm_constraint_t cnst = elem.constraint;
699 if (cnst->sharing_policy) {
700 // Remember: shared constraints require that sum(elem.value * var->value) < cnst->bound
701 double_update(&(cnst->remaining), elem.consumption_weight * var->value, cnst->bound * sg_maxmin_precision);
702 double_update(&(cnst->usage), elem.consumption_weight / var->sharing_weight, sg_maxmin_precision);
703 // If the constraint is saturated, remove it from the set of active constraints (light_tab)
704 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
705 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
706 if (cnst->cnst_light) {
707 int index = (cnst->cnst_light-cnst_light_tab);
708 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f ",
709 index,cnst_light_num, cnst->usage, cnst->remaining, cnst->bound);
710 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
711 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
713 cnst->cnst_light = nullptr;
716 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
718 make_elem_inactive(&elem);
720 // Remember: non-shared constraints only require that max(elem.value * var->value) < cnst->bound
722 make_elem_inactive(&elem);
723 xbt_swag_t elem_list = &(cnst->enabled_element_set);
724 xbt_swag_foreach(_elem, elem_list) {
725 lmm_element_t elem2 = static_cast<lmm_element_t>(_elem);
726 xbt_assert(elem2->variable->sharing_weight > 0);
727 if (elem2->variable->value > 0)
729 if (elem2->consumption_weight > 0)
730 cnst->usage = std::max(cnst->usage, elem2->consumption_weight / elem2->variable->sharing_weight);
732 //If the constraint is saturated, remove it from the set of active constraints (light_tab)
733 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
734 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
735 if(cnst->cnst_light) {
736 int index = (cnst->cnst_light-cnst_light_tab);
737 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
738 "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f ", index,cnst_light_num, cnst,
739 cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining, cnst->bound);
740 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
741 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
743 cnst->cnst_light = nullptr;
746 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
747 xbt_assert(cnst->active_element_set.count>0, "Should not keep a maximum constraint that has no active"
748 " element! You want to check the maxmin precision and possible rounding effects." );
752 xbt_swag_remove(var, var_list);
755 /* Find out which variables reach the maximum */
758 saturated_constraint_set.clear();
760 for(pos=0; pos<cnst_light_num; pos++){
761 xbt_assert(cnst_light_tab[pos].cnst->active_element_set.count>0, "Cannot saturate more a constraint that has"
762 " no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>)"
763 " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
764 "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
765 cnst_light_tab[pos].cnst->usage, sg_maxmin_precision, cnst_light_tab[pos-1].cnst->usage);
766 saturated_constraint_set_update(cnst_light_tab[pos].remaining_over_usage, pos, saturated_constraint_set,
770 saturated_variable_set_update(cnst_light_tab, saturated_constraint_set, this);
772 } while (cnst_light_num > 0);
775 if (selective_update_active)
776 remove_all_modified_set();
778 if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
784 delete[] cnst_light_tab;
788 void lmm_solve(lmm_system_t sys)
793 /** \brief Attribute the value bound to var->bound.
795 * \param sys the lmm_system_t
796 * \param var the lmm_variable_t
797 * \param bound the new bound to associate with var
799 * Makes var->bound equal to bound. Whenever this function is called a change is signed in the system. To
800 * avoid false system changing detection it is a good idea to test (bound != 0) before calling it.
802 void s_lmm_system_t::update_variable_bound(lmm_variable_t var, double bound)
807 if (not var->cnsts.empty())
808 update_modified_set(var->cnsts[0].constraint);
811 /** \brief Measure the minimum concurrency slack across all constraints where the given var is involved */
812 int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var)
814 int minslack = std::numeric_limits<int>::max();
815 for (s_lmm_element_t const& elem : var->cnsts) {
816 int slack = elem.constraint->get_concurrency_slack();
817 if (slack < minslack) {
818 // This is only an optimization, to avoid looking at more constraints when slack is already zero
827 /* /Check if a variable can be enabled
829 * Make sure to set staged_weight before, if your intent is only to check concurrency
831 int lmm_can_enable_var(lmm_variable_t var){
832 return var->staged_weight>0 && lmm_cnstrs_min_concurrency_slack(var)>=var->concurrency_share;
835 //Small remark: In this implementation of lmm_enable_var and lmm_disable_var, we will meet multiple times with var when
836 // running sys->update_modified_set.
837 // A priori not a big performance issue, but we might do better by calling sys->update_modified_set within the for loops
838 // (after doing the first for enabling==1, and before doing the last for disabling==1)
839 void s_lmm_system_t::enable_var(lmm_variable_t var)
841 xbt_assert(not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug) || lmm_can_enable_var(var));
843 var->sharing_weight = var->staged_weight;
844 var->staged_weight = 0;
846 // Enabling the variable, move to var to list head. Subtlety is: here, we need to call update_modified_set AFTER
847 // moving at least one element of var.
849 xbt_swag_remove(var, &variable_set);
850 xbt_swag_insert_at_head(var, &variable_set);
851 for (s_lmm_element_t& elem : var->cnsts) {
852 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
853 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
854 lmm_increase_concurrency(&elem);
856 if (not var->cnsts.empty())
857 update_modified_set(var->cnsts[0].constraint);
859 // When used within on_disabled_var, we would get an assertion fail, because transiently there can be variables
860 // that are staged and could be activated.
861 // Anyway, caller functions all call check_concurrency() in the end.
864 void s_lmm_system_t::disable_var(lmm_variable_t var)
866 xbt_assert(not var->staged_weight, "Staged weight should have been cleared");
867 // Disabling the variable, move to var to list tail. Subtlety is: here, we need to call update_modified_set
868 // BEFORE moving the last element of var.
869 xbt_swag_remove(var, &variable_set);
870 xbt_swag_insert_at_tail(var, &variable_set);
871 if (not var->cnsts.empty())
872 update_modified_set(var->cnsts[0].constraint);
873 for (s_lmm_element_t& elem : var->cnsts) {
874 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
875 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
877 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
879 lmm_decrease_concurrency(&elem);
882 var->sharing_weight = 0.0;
883 var->staged_weight=0.0;
888 /* /brief Find variables that can be enabled and enable them.
890 * Assuming that the variable has already been removed from non-zero weights
891 * Can we find a staged variable to add?
892 * If yes, check that none of the constraints that this variable is involved in is at the limit of its concurrency
893 * And then add it to enabled variables
895 void s_lmm_system_t::on_disabled_var(lmm_constraint_t cnstr)
897 if (cnstr->get_concurrency_limit() < 0)
900 int numelem = xbt_swag_size(&(cnstr->disabled_element_set));
904 lmm_element_t elem = (lmm_element_t)xbt_swag_getFirst(&(cnstr->disabled_element_set));
906 //Cannot use xbt_swag_foreach, because lmm_enable_var will modify disabled_element_set.. within the loop
907 while (numelem-- && elem) {
909 lmm_element_t nextelem = (lmm_element_t)xbt_swag_getNext(elem, cnstr->disabled_element_set.offset);
911 if (elem->variable->staged_weight > 0 && lmm_can_enable_var(elem->variable)) {
912 //Found a staged variable
913 //TODOLATER: Add random timing function to model reservation protocol fuzziness? Then how to make sure that
914 //staged variables will eventually be called?
915 enable_var(elem->variable);
918 xbt_assert(cnstr->concurrency_current <= cnstr->get_concurrency_limit(), "Concurrency overflow!");
919 if (cnstr->concurrency_current == cnstr->get_concurrency_limit())
925 //We could get an assertion fail, because transiently there can be variables that are staged and could be activated.
926 //And we need to go through all constraints of the disabled var before getting back a coherent state.
927 // Anyway, caller functions all call check_concurrency() in the end.
930 /* \brief update the weight of a variable, and enable/disable it.
931 * @return Returns whether a change was made
933 void s_lmm_system_t::update_variable_weight(lmm_variable_t var, double weight)
935 xbt_assert(weight>=0,"Variable weight should not be negative!");
937 if (weight == var->sharing_weight)
940 int enabling_var = (weight > 0 && var->sharing_weight <= 0);
941 int disabling_var = (weight <= 0 && var->sharing_weight > 0);
943 XBT_IN("(sys=%p, var=%p, weight=%f)", this, var, weight);
947 //Are we enabling this variable?
949 var->staged_weight = weight;
950 int minslack = lmm_cnstrs_min_concurrency_slack(var);
951 if (minslack < var->concurrency_share) {
952 XBT_DEBUG("Staging var (instead of enabling) because min concurrency slack %i, with weight %f and concurrency"
953 " share %i", minslack, weight, var->concurrency_share);
956 XBT_DEBUG("Enabling var with min concurrency slack %i", minslack);
958 } else if (disabling_var){
959 //Are we disabling this variable?
962 var->sharing_weight = weight;
970 double lmm_get_variable_weight(lmm_variable_t var)
972 return var->sharing_weight;
975 void s_lmm_system_t::update_constraint_bound(lmm_constraint_t cnst, double bound)
978 update_modified_set(cnst);
982 /** \brief Update the constraint set propagating recursively to other constraints so the system should not be entirely
985 * \param sys the lmm_system_t
986 * \param cnst the lmm_constraint_t affected by the change
988 * A recursive algorithm to optimize the system recalculation selecting only constraints that have changed. Each
989 * constraint change is propagated to the list of constraints for each variable.
991 void s_lmm_system_t::update_modified_set_rec(lmm_constraint_t cnst)
995 xbt_swag_foreach(_elem, &cnst->enabled_element_set) {
996 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
997 for (s_lmm_element_t const& elem : var->cnsts) {
998 if (var->visited == visited_counter)
1000 if (elem.constraint != cnst && not xbt_swag_belongs(elem.constraint, &modified_constraint_set)) {
1001 xbt_swag_insert(elem.constraint, &modified_constraint_set);
1002 update_modified_set_rec(elem.constraint);
1005 //var will be ignored in later visits as long as sys->visited_counter does not move
1006 var->visited = visited_counter;
1010 void s_lmm_system_t::update_modified_set(lmm_constraint_t cnst)
1012 /* nothing to do if selective update isn't active */
1013 if (selective_update_active && not xbt_swag_belongs(cnst, &modified_constraint_set)) {
1014 xbt_swag_insert(cnst, &modified_constraint_set);
1015 update_modified_set_rec(cnst);
1019 void s_lmm_system_t::remove_all_modified_set()
1021 // We cleverly un-flag all variables just by incrementing visited_counter
1022 // In effect, the var->visited value will no more be equal to visited counter
1023 // To be clean, when visited counter has wrapped around, we force these var->visited values so that variables that
1024 // were in the modified a long long time ago are not wrongly skipped here, which would lead to very nasty bugs
1025 // (i.e. not readibily reproducible, and requiring a lot of run time before happening).
1026 if (++visited_counter == 1) {
1027 /* the counter wrapped around, reset each variable->visited */
1029 xbt_swag_foreach(_var, &variable_set)
1030 ((lmm_variable_t)_var)->visited = 0;
1032 xbt_swag_reset(&modified_constraint_set);
1036 * Returns resource load (in flop per second, or byte per second, or similar)
1038 * If the resource is shared (the default case), the load is sum of resource usage made by every variables located on
1041 * If the resource is not shared (ie in FATPIPE mode), then the load is the max (not the sum) of all resource usages
1042 * located on this resource.
1044 * \param cnst the lmm_constraint_t associated to the resource
1046 double s_lmm_constraint_t::get_usage() const
1049 const_xbt_swag_t elem_list = &enabled_element_set;
1052 xbt_swag_foreach(_elem, elem_list)
1054 lmm_element_t elem = (lmm_element_t)_elem;
1055 if (elem->consumption_weight > 0) {
1057 usage += elem->consumption_weight * elem->variable->value;
1058 else if (usage < elem->consumption_weight * elem->variable->value)
1059 usage = std::max(usage, elem->consumption_weight * elem->variable->value);
1065 int s_lmm_constraint_t::get_variable_amount() const
1068 const_xbt_swag_t elem_list = &enabled_element_set;
1071 xbt_swag_foreach(_elem, elem_list) {
1072 lmm_element_t elem = (lmm_element_t)_elem;
1073 if (elem->consumption_weight > 0)