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 int s_lmm_element_t::get_concurrency() const
36 //Ignore element with weight less than one (e.g. cross-traffic)
37 return (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 void s_lmm_element_t::decrease_concurrency()
48 xbt_assert(constraint->concurrency_current >= get_concurrency());
49 constraint->concurrency_current -= get_concurrency();
52 void s_lmm_element_t::increase_concurrency()
54 constraint->concurrency_current += get_concurrency();
56 if (constraint->concurrency_current > constraint->concurrency_maximum)
57 constraint->concurrency_maximum = constraint->concurrency_current;
59 xbt_assert(constraint->get_concurrency_limit() < 0 ||
60 constraint->concurrency_current <= constraint->get_concurrency_limit(),
61 "Concurrency limit overflow!");
64 void s_lmm_system_t::check_concurrency()
66 // These checks are very expensive, so do them only if we want to debug SURF LMM
67 if (not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug))
71 xbt_swag_foreach(cnstIt, &constraint_set)
73 lmm_constraint_t cnst = (lmm_constraint_t)cnstIt;
76 xbt_swag_foreach(elemIt, &(cnst->enabled_element_set))
78 lmm_element_t elem = (lmm_element_t)elemIt;
79 xbt_assert(elem->variable->sharing_weight > 0);
80 concurrency += elem->get_concurrency();
83 xbt_swag_foreach(elemIt, &(cnst->disabled_element_set))
85 lmm_element_t elem = (lmm_element_t)elemIt;
86 // We should have staged variables only if concurrency is reached in some constraint
87 xbt_assert(cnst->get_concurrency_limit() < 0 || elem->variable->staged_weight == 0 ||
88 lmm_cnstrs_min_concurrency_slack(elem->variable) < elem->variable->concurrency_share,
89 "should not have staged variable!");
92 xbt_assert(cnst->get_concurrency_limit() < 0 || cnst->get_concurrency_limit() >= concurrency,
93 "concurrency check failed!");
94 xbt_assert(cnst->concurrency_current == concurrency, "concurrency_current is out-of-date!");
97 // Check that for each variable, all corresponding elements are in the same state (i.e. same element sets)
99 xbt_swag_foreach(varIt, &variable_set)
101 lmm_variable_t var = (lmm_variable_t)varIt;
103 if (var->cnsts.empty())
106 lmm_element_t elem = &var->cnsts[0];
107 int belong_to_enabled = xbt_swag_belongs(elem, &(elem->constraint->enabled_element_set));
108 int belong_to_disabled = xbt_swag_belongs(elem, &(elem->constraint->disabled_element_set));
109 int belong_to_active = xbt_swag_belongs(elem, &(elem->constraint->active_element_set));
111 for (s_lmm_element_t const& elem : var->cnsts) {
112 xbt_assert(belong_to_enabled == xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)),
113 "Variable inconsistency (1): enabled_element_set");
114 xbt_assert(belong_to_disabled == xbt_swag_belongs(&elem, &(elem.constraint->disabled_element_set)),
115 "Variable inconsistency (2): disabled_element_set");
116 xbt_assert(belong_to_active == xbt_swag_belongs(&elem, &(elem.constraint->active_element_set)),
117 "Variable inconsistency (3): active_element_set");
122 void s_lmm_system_t::var_free(lmm_variable_t var)
124 XBT_IN("(sys=%p, var=%p)", this, var);
127 // TODOLATER Can do better than that by leaving only the variable in only one enabled_element_set, call
128 // update_modified_set, and then remove it..
129 if (not var->cnsts.empty())
130 update_modified_set(var->cnsts[0].constraint);
132 for (s_lmm_element_t& elem : var->cnsts) {
133 if (var->sharing_weight > 0)
134 elem.decrease_concurrency();
135 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
136 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
137 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
138 int nelements = xbt_swag_size(&(elem.constraint->enabled_element_set)) +
139 xbt_swag_size(&(elem.constraint->disabled_element_set));
141 make_constraint_inactive(elem.constraint);
143 on_disabled_var(elem.constraint);
150 xbt_mallocator_release(variable_mallocator, var);
154 s_lmm_system_t::s_lmm_system_t(bool selective_update)
156 s_lmm_variable_t var;
157 s_lmm_constraint_t cnst;
160 selective_update_active = selective_update;
163 XBT_DEBUG("Setting selective_update_active flag to %d", selective_update_active);
165 xbt_swag_init(&variable_set, xbt_swag_offset(var, variable_set_hookup));
166 xbt_swag_init(&constraint_set, xbt_swag_offset(cnst, constraint_set_hookup));
168 xbt_swag_init(&active_constraint_set, xbt_swag_offset(cnst, active_constraint_set_hookup));
170 xbt_swag_init(&modified_constraint_set, xbt_swag_offset(cnst, modified_constraint_set_hookup));
171 xbt_swag_init(&saturated_variable_set, xbt_swag_offset(var, saturated_variable_set_hookup));
172 xbt_swag_init(&saturated_constraint_set, xbt_swag_offset(cnst, saturated_constraint_set_hookup));
174 keep_track = nullptr;
175 variable_mallocator = xbt_mallocator_new(65536, s_lmm_system_t::variable_mallocator_new_f,
176 s_lmm_system_t::variable_mallocator_free_f, nullptr);
177 solve_fun = &lmm_solve;
180 s_lmm_system_t::~s_lmm_system_t()
183 lmm_constraint_t cnst;
185 while ((var = extract_variable())) {
186 auto demangled = simgrid::xbt::demangle(typeid(*var->id).name());
187 XBT_WARN("Probable bug: a %s variable (#%d) not removed before the LMM system destruction.", demangled.get(),
191 while ((cnst = extract_constraint()))
194 xbt_mallocator_free(variable_mallocator);
197 void s_lmm_system_t::cnst_free(lmm_constraint_t cnst)
199 make_constraint_inactive(cnst);
203 s_lmm_constraint_t::s_lmm_constraint_t(void* id_value, double bound_value)
205 s_lmm_element_t elem;
208 id_int = Global_debug_id++;
209 xbt_swag_init(&enabled_element_set, xbt_swag_offset(elem, enabled_element_set_hookup));
210 xbt_swag_init(&disabled_element_set, xbt_swag_offset(elem, disabled_element_set_hookup));
211 xbt_swag_init(&active_element_set, xbt_swag_offset(elem, active_element_set_hookup));
216 concurrency_limit = sg_concurrency_limit;
217 concurrency_current = 0;
218 concurrency_maximum = 0;
219 sharing_policy = 1; /* FIXME: don't hardcode the value */
223 cnst_light = nullptr;
226 lmm_constraint_t s_lmm_system_t::constraint_new(void* id, double bound_value)
228 lmm_constraint_t cnst = new s_lmm_constraint_t(id, bound_value);
229 insert_constraint(cnst);
233 void* s_lmm_system_t::variable_mallocator_new_f()
235 return new s_lmm_variable_t;
238 void s_lmm_system_t::variable_mallocator_free_f(void* var)
240 delete static_cast<lmm_variable_t>(var);
243 lmm_variable_t s_lmm_system_t::variable_new(simgrid::surf::Action* id, double sharing_weight, double bound,
244 int number_of_constraints)
246 XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)", this, id, sharing_weight, bound, number_of_constraints);
248 lmm_variable_t var = (lmm_variable_t)xbt_mallocator_get(variable_mallocator);
250 var->id_int = Global_debug_id++;
251 var->cnsts.reserve(number_of_constraints);
252 var->sharing_weight = sharing_weight;
253 var->staged_weight = 0.0;
255 var->concurrency_share = 1;
257 var->visited = visited_counter - 1;
260 var->func_f = func_f_def;
261 var->func_fp = func_fp_def;
262 var->func_fpi = func_fpi_def;
264 var->variable_set_hookup.next = nullptr;
265 var->variable_set_hookup.prev = nullptr;
266 var->saturated_variable_set_hookup.next = nullptr;
267 var->saturated_variable_set_hookup.prev = nullptr;
270 xbt_swag_insert_at_head(var, &variable_set);
272 xbt_swag_insert_at_tail(var, &variable_set);
274 XBT_OUT(" returns %p", var);
278 void s_lmm_system_t::variable_free(lmm_variable_t var)
280 remove_variable(var);
284 double lmm_variable_getvalue(lmm_variable_t var)
289 void lmm_variable_concurrency_share_set(lmm_variable_t var, short int concurrency_share)
291 var->concurrency_share=concurrency_share;
294 double lmm_variable_getbound(lmm_variable_t var)
299 void s_lmm_system_t::expand(lmm_constraint_t cnst, lmm_variable_t var, double consumption_weight)
303 //Check if this variable already has an active element in this constraint
304 //If it does, substract it from the required slack
305 int current_share = 0;
306 if(var->concurrency_share>1){
307 for (s_lmm_element_t& elem : var->cnsts) {
308 if (elem.constraint == cnst && xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)))
309 current_share += elem.get_concurrency();
313 //Check if we need to disable the variable
314 if (var->sharing_weight > 0 && var->concurrency_share - current_share > cnst->get_concurrency_slack()) {
315 double weight = var->sharing_weight;
317 for (s_lmm_element_t const& elem : var->cnsts)
318 on_disabled_var(elem.constraint);
319 consumption_weight = 0;
320 var->staged_weight=weight;
321 xbt_assert(not var->sharing_weight);
324 xbt_assert(var->cnsts.size() < var->cnsts.capacity(), "Too much constraints");
326 var->cnsts.resize(var->cnsts.size() + 1);
327 s_lmm_element_t& elem = var->cnsts.back();
329 elem.consumption_weight = consumption_weight;
330 elem.constraint = cnst;
333 if (var->sharing_weight) {
334 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
335 elem.increase_concurrency();
337 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
339 if (not selective_update_active) {
340 make_constraint_active(cnst);
341 } else if (elem.consumption_weight > 0 || var->sharing_weight > 0) {
342 make_constraint_active(cnst);
343 update_modified_set(cnst);
344 //TODOLATER: Why do we need this second call?
345 if (var->cnsts.size() > 1)
346 update_modified_set(var->cnsts[0].constraint);
352 void s_lmm_system_t::expand_add(lmm_constraint_t cnst, lmm_variable_t var, double value)
358 //BEWARE: In case you have multiple elements in one constraint, this will always add value to the first element.
359 auto elem_it = std::find_if(begin(var->cnsts), end(var->cnsts),
360 [&cnst](s_lmm_element_t const& x) { return x.constraint == cnst; });
361 if (elem_it != end(var->cnsts)) {
362 s_lmm_element_t& elem = *elem_it;
363 if (var->sharing_weight)
364 elem.decrease_concurrency();
366 if (cnst->sharing_policy)
367 elem.consumption_weight += value;
369 elem.consumption_weight = std::max(elem.consumption_weight, value);
371 //We need to check that increasing value of the element does not cross the concurrency limit
372 if (var->sharing_weight) {
373 if (cnst->get_concurrency_slack() < elem.get_concurrency()) {
374 double weight = var->sharing_weight;
376 for (s_lmm_element_t const& elem2 : var->cnsts)
377 on_disabled_var(elem2.constraint);
378 var->staged_weight=weight;
379 xbt_assert(not var->sharing_weight);
381 elem.increase_concurrency();
383 update_modified_set(cnst);
385 expand(cnst, var, value);
390 lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
392 if (num < var->cnsts.size())
393 return (var->cnsts[num].constraint);
398 double lmm_get_cnst_weight_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
400 if (num < var->cnsts.size())
401 return (var->cnsts[num].consumption_weight);
406 int lmm_get_number_of_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var)
408 return (var->cnsts.size());
411 lmm_variable_t s_lmm_constraint_t::get_variable(lmm_element_t* elem) const
413 if (*elem == nullptr) {
414 // That is the first call, pick the first element among enabled_element_set (or disabled_element_set if
415 // enabled_element_set is empty)
416 *elem = (lmm_element_t)xbt_swag_getFirst(&enabled_element_set);
417 if (*elem == nullptr)
418 *elem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
420 //elem is not null, so we carry on
421 if (xbt_swag_belongs(*elem, &enabled_element_set)) {
422 //Look at enabled_element_set, and jump to disabled_element_set when finished
423 *elem = (lmm_element_t)xbt_swag_getNext(*elem, enabled_element_set.offset);
424 if (*elem == nullptr)
425 *elem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
427 *elem = (lmm_element_t)xbt_swag_getNext(*elem, disabled_element_set.offset);
431 return (*elem)->variable;
436 //if we modify the swag between calls, normal version may loop forever
437 //this safe version ensures that we browse the swag elements only once
438 lmm_variable_t s_lmm_constraint_t::get_variable_safe(lmm_element_t* elem, lmm_element_t* nextelem, int* numelem) const
440 if (*elem == nullptr) {
441 *elem = (lmm_element_t)xbt_swag_getFirst(&enabled_element_set);
442 *numelem = xbt_swag_size(&enabled_element_set) + xbt_swag_size(&disabled_element_set) - 1;
443 if (*elem == nullptr)
444 *elem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
453 //elem is not null, so we carry on
454 if (xbt_swag_belongs(*elem, &enabled_element_set)) {
455 //Look at enabled_element_set, and jump to disabled_element_set when finished
456 *nextelem = (lmm_element_t)xbt_swag_getNext(*elem, enabled_element_set.offset);
457 if (*nextelem == nullptr)
458 *nextelem = (lmm_element_t)xbt_swag_getFirst(&disabled_element_set);
460 *nextelem = (lmm_element_t)xbt_swag_getNext(*elem, disabled_element_set.offset);
462 return (*elem)->variable;
467 void *lmm_variable_id(lmm_variable_t var)
472 static inline void saturated_constraint_set_update(double usage, int cnst_light_num,
473 dyn_light_t& saturated_constraint_set, double* min_usage)
475 xbt_assert(usage > 0,"Impossible");
477 if (*min_usage < 0 || *min_usage > usage) {
479 XBT_HERE(" min_usage=%f (cnst->remaining / cnst->usage =%f)", *min_usage, usage);
480 saturated_constraint_set.assign(1, cnst_light_num);
481 } else if (*min_usage == usage) {
482 saturated_constraint_set.emplace_back(cnst_light_num);
486 static inline void saturated_variable_set_update(s_lmm_constraint_light_t* cnst_light_tab,
487 const dyn_light_t& saturated_constraint_set, lmm_system_t sys)
489 /* Add active variables (i.e. variables that need to be set) from the set of constraints to saturate (cnst_light_tab)*/
490 for (int const& saturated_cnst : saturated_constraint_set) {
491 lmm_constraint_light_t cnst = &cnst_light_tab[saturated_cnst];
493 xbt_swag_t elem_list = &(cnst->cnst->active_element_set);
494 xbt_swag_foreach(_elem, elem_list) {
495 lmm_element_t elem = (lmm_element_t)_elem;
496 //Visiting active_element_set, so, by construction, should never get a zero weight, correct?
497 xbt_assert(elem->variable->sharing_weight > 0);
498 if (elem->consumption_weight > 0)
499 xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
504 void s_lmm_system_t::print()
506 std::string buf = std::string("MAX-MIN ( ");
509 /* Printing Objective */
510 xbt_swag_t var_list = &variable_set;
511 xbt_swag_foreach(_var, var_list) {
512 lmm_variable_t var = (lmm_variable_t)_var;
513 buf = buf + "'" + std::to_string(var->id_int) + "'(" + std::to_string(var->sharing_weight) + ") ";
516 XBT_DEBUG("%20s", buf.c_str());
519 XBT_DEBUG("Constraints");
520 /* Printing Constraints */
522 xbt_swag_t cnst_list = &active_constraint_set;
523 xbt_swag_foreach(_cnst, cnst_list) {
524 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
526 //Show the enabled variables
528 xbt_swag_t elem_list = &(cnst->enabled_element_set);
530 buf += ((cnst->sharing_policy) ? "(" : "max(");
531 xbt_swag_foreach(_elem, elem_list) {
532 lmm_element_t elem = (lmm_element_t)_elem;
533 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
534 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
535 if(cnst->sharing_policy)
536 sum += elem->consumption_weight * elem->variable->value;
538 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
540 //TODO: Adding disabled elements only for test compatibility, but do we really want them to be printed?
541 elem_list = &(cnst->disabled_element_set);
542 xbt_swag_foreach(_elem, elem_list) {
543 lmm_element_t elem = (lmm_element_t)_elem;
544 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
545 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
546 if(cnst->sharing_policy)
547 sum += elem->consumption_weight * elem->variable->value;
549 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
552 buf = buf + "0) <= " + std::to_string(cnst->bound) + " ('" + std::to_string(cnst->id_int) + "')";
554 if (not cnst->sharing_policy) {
555 buf += " [MAX-Constraint]";
557 XBT_DEBUG("%s", buf.c_str());
559 xbt_assert(not double_positive(sum - cnst->bound, cnst->bound * sg_maxmin_precision),
560 "Incorrect value (%f is not smaller than %f): %g", sum, cnst->bound, sum - cnst->bound);
563 XBT_DEBUG("Variables");
564 /* Printing Result */
565 xbt_swag_foreach(_var, var_list) {
566 lmm_variable_t var = (lmm_variable_t)_var;
567 if (var->bound > 0) {
568 XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->sharing_weight, var->value, var->bound);
569 xbt_assert(not double_positive(var->value - var->bound, var->bound * sg_maxmin_precision),
570 "Incorrect value (%f is not smaller than %f", var->value, var->bound);
572 XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->sharing_weight, var->value);
577 void s_lmm_system_t::solve()
582 double min_usage = -1;
583 double min_bound = -1;
588 XBT_IN("(sys=%p)", this);
590 /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only constraints
591 * that changed are considered. Otherwise all constraints with active actions are considered.
593 xbt_swag_t cnst_list = selective_update_active ? &modified_constraint_set : &active_constraint_set;
595 XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
596 /* Init: Only modified code portions: reset the value of active variables */
597 xbt_swag_foreach(_cnst, cnst_list) {
598 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
599 xbt_swag_t elem_list = &(cnst->enabled_element_set);
600 xbt_swag_foreach(_elem, elem_list) {
601 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
602 xbt_assert(var->sharing_weight > 0.0);
607 s_lmm_constraint_light_t* cnst_light_tab = new s_lmm_constraint_light_t[xbt_swag_size(cnst_list)]();
608 int cnst_light_num = 0;
609 dyn_light_t saturated_constraint_set;
611 xbt_swag_foreach_safe(_cnst, _cnst_next, cnst_list) {
612 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
613 /* INIT: Collect constraints that actually need to be saturated (i.e remaining and usage are strictly positive)
614 * into cnst_light_tab. */
615 cnst->remaining = cnst->bound;
616 if (not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision))
619 xbt_swag_t elem_list = &(cnst->enabled_element_set);
620 xbt_swag_foreach(_elem, elem_list) {
621 lmm_element_t elem = (lmm_element_t)_elem;
622 xbt_assert(elem->variable->sharing_weight > 0);
623 if (elem->consumption_weight > 0) {
624 if (cnst->sharing_policy)
625 cnst->usage += elem->consumption_weight / elem->variable->sharing_weight;
626 else if (cnst->usage < elem->consumption_weight / elem->variable->sharing_weight)
627 cnst->usage = elem->consumption_weight / elem->variable->sharing_weight;
630 simgrid::surf::Action *action = static_cast<simgrid::surf::Action*>(elem->variable->id);
631 if (keep_track && not action->is_linked())
632 keep_track->push_back(*action);
635 XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst->id_int, cnst->usage,
636 cnst->remaining, cnst->concurrency_current, cnst->concurrency_maximum, cnst->get_concurrency_limit());
637 /* Saturated constraints update */
639 if(cnst->usage > 0) {
640 cnst_light_tab[cnst_light_num].cnst = cnst;
641 cnst->cnst_light = &(cnst_light_tab[cnst_light_num]);
642 cnst_light_tab[cnst_light_num].remaining_over_usage = cnst->remaining / cnst->usage;
643 saturated_constraint_set_update(cnst_light_tab[cnst_light_num].remaining_over_usage,
644 cnst_light_num, saturated_constraint_set, &min_usage);
645 xbt_assert(cnst->active_element_set.count>0, "There is no sense adding a constraint that has no active element!");
650 saturated_variable_set_update(cnst_light_tab, saturated_constraint_set, this);
652 /* Saturated variables update */
654 /* Fix the variables that have to be */
655 xbt_swag_t var_list = &saturated_variable_set;
657 lmm_variable_t var = nullptr;
658 xbt_swag_foreach(_var, var_list) {
659 var = (lmm_variable_t)_var;
660 if (var->sharing_weight <= 0.0)
662 /* First check if some of these variables could reach their upper bound and update min_bound accordingly. */
663 XBT_DEBUG("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f", var->id_int,
664 var->bound, var->sharing_weight, min_usage, var->bound * var->sharing_weight);
665 if ((var->bound > 0) && (var->bound * var->sharing_weight < min_usage)) {
667 min_bound = var->bound * var->sharing_weight;
669 min_bound = std::min(min_bound, (var->bound * var->sharing_weight));
670 XBT_DEBUG("Updated min_bound=%f", min_bound);
674 while ((var = (lmm_variable_t)xbt_swag_getFirst(var_list))) {
676 //If no variable could reach its bound, deal iteratively the constraints usage ( at worst one constraint is
677 // saturated at each cycle)
678 var->value = min_usage / var->sharing_weight;
679 XBT_DEBUG("Setting var (%d) value to %f\n", var->id_int, var->value);
681 //If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
682 if (double_equals(min_bound, var->bound * var->sharing_weight, sg_maxmin_precision)) {
683 var->value = var->bound;
684 XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
686 // Variables which bound is different are not considered for this cycle, but they will be afterwards.
687 XBT_DEBUG("Do not consider %p (%d) \n", var, var->id_int);
688 xbt_swag_remove(var, var_list);
692 XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ", min_usage, var->id_int, var->sharing_weight,
693 var->id_int, var->value);
695 /* Update the usage of contraints where this variable is involved */
696 for (s_lmm_element_t& elem : var->cnsts) {
697 lmm_constraint_t cnst = elem.constraint;
698 if (cnst->sharing_policy) {
699 // Remember: shared constraints require that sum(elem.value * var->value) < cnst->bound
700 double_update(&(cnst->remaining), elem.consumption_weight * var->value, cnst->bound * sg_maxmin_precision);
701 double_update(&(cnst->usage), elem.consumption_weight / var->sharing_weight, sg_maxmin_precision);
702 // If the constraint is saturated, remove it from the set of active constraints (light_tab)
703 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
704 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
705 if (cnst->cnst_light) {
706 int index = (cnst->cnst_light-cnst_light_tab);
707 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f ",
708 index,cnst_light_num, cnst->usage, cnst->remaining, cnst->bound);
709 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
710 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
712 cnst->cnst_light = nullptr;
715 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
717 elem.make_inactive();
719 // Remember: non-shared constraints only require that max(elem.value * var->value) < cnst->bound
721 elem.make_inactive();
722 xbt_swag_t elem_list = &(cnst->enabled_element_set);
723 xbt_swag_foreach(_elem, elem_list) {
724 lmm_element_t elem2 = static_cast<lmm_element_t>(_elem);
725 xbt_assert(elem2->variable->sharing_weight > 0);
726 if (elem2->variable->value > 0)
728 if (elem2->consumption_weight > 0)
729 cnst->usage = std::max(cnst->usage, elem2->consumption_weight / elem2->variable->sharing_weight);
731 //If the constraint is saturated, remove it from the set of active constraints (light_tab)
732 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
733 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
734 if(cnst->cnst_light) {
735 int index = (cnst->cnst_light-cnst_light_tab);
736 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
737 "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f ", index,cnst_light_num, cnst,
738 cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining, cnst->bound);
739 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
740 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
742 cnst->cnst_light = nullptr;
745 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
746 xbt_assert(cnst->active_element_set.count>0, "Should not keep a maximum constraint that has no active"
747 " element! You want to check the maxmin precision and possible rounding effects." );
751 xbt_swag_remove(var, var_list);
754 /* Find out which variables reach the maximum */
757 saturated_constraint_set.clear();
759 for(pos=0; pos<cnst_light_num; pos++){
760 xbt_assert(cnst_light_tab[pos].cnst->active_element_set.count>0, "Cannot saturate more a constraint that has"
761 " no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>)"
762 " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
763 "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
764 cnst_light_tab[pos].cnst->usage, sg_maxmin_precision, cnst_light_tab[pos-1].cnst->usage);
765 saturated_constraint_set_update(cnst_light_tab[pos].remaining_over_usage, pos, saturated_constraint_set,
769 saturated_variable_set_update(cnst_light_tab, saturated_constraint_set, this);
771 } while (cnst_light_num > 0);
774 if (selective_update_active)
775 remove_all_modified_set();
777 if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
783 delete[] cnst_light_tab;
787 void lmm_solve(lmm_system_t sys)
792 /** \brief Attribute the value bound to var->bound.
794 * \param sys the lmm_system_t
795 * \param var the lmm_variable_t
796 * \param bound the new bound to associate with var
798 * Makes var->bound equal to bound. Whenever this function is called a change is signed in the system. To
799 * avoid false system changing detection it is a good idea to test (bound != 0) before calling it.
801 void s_lmm_system_t::update_variable_bound(lmm_variable_t var, double bound)
806 if (not var->cnsts.empty())
807 update_modified_set(var->cnsts[0].constraint);
810 /** \brief Measure the minimum concurrency slack across all constraints where the given var is involved */
811 int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var)
813 int minslack = std::numeric_limits<int>::max();
814 for (s_lmm_element_t const& elem : var->cnsts) {
815 int slack = elem.constraint->get_concurrency_slack();
816 if (slack < minslack) {
817 // This is only an optimization, to avoid looking at more constraints when slack is already zero
826 /* /Check if a variable can be enabled
828 * Make sure to set staged_weight before, if your intent is only to check concurrency
830 int lmm_can_enable_var(lmm_variable_t var){
831 return var->staged_weight>0 && lmm_cnstrs_min_concurrency_slack(var)>=var->concurrency_share;
834 //Small remark: In this implementation of lmm_enable_var and lmm_disable_var, we will meet multiple times with var when
835 // running sys->update_modified_set.
836 // A priori not a big performance issue, but we might do better by calling sys->update_modified_set within the for loops
837 // (after doing the first for enabling==1, and before doing the last for disabling==1)
838 void s_lmm_system_t::enable_var(lmm_variable_t var)
840 xbt_assert(not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug) || lmm_can_enable_var(var));
842 var->sharing_weight = var->staged_weight;
843 var->staged_weight = 0;
845 // Enabling the variable, move to var to list head. Subtlety is: here, we need to call update_modified_set AFTER
846 // moving at least one element of var.
848 xbt_swag_remove(var, &variable_set);
849 xbt_swag_insert_at_head(var, &variable_set);
850 for (s_lmm_element_t& elem : var->cnsts) {
851 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
852 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
853 elem.increase_concurrency();
855 if (not var->cnsts.empty())
856 update_modified_set(var->cnsts[0].constraint);
858 // When used within on_disabled_var, we would get an assertion fail, because transiently there can be variables
859 // that are staged and could be activated.
860 // Anyway, caller functions all call check_concurrency() in the end.
863 void s_lmm_system_t::disable_var(lmm_variable_t var)
865 xbt_assert(not var->staged_weight, "Staged weight should have been cleared");
866 // Disabling the variable, move to var to list tail. Subtlety is: here, we need to call update_modified_set
867 // BEFORE moving the last element of var.
868 xbt_swag_remove(var, &variable_set);
869 xbt_swag_insert_at_tail(var, &variable_set);
870 if (not var->cnsts.empty())
871 update_modified_set(var->cnsts[0].constraint);
872 for (s_lmm_element_t& elem : var->cnsts) {
873 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
874 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
876 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
878 elem.decrease_concurrency();
881 var->sharing_weight = 0.0;
882 var->staged_weight=0.0;
887 /* /brief Find variables that can be enabled and enable them.
889 * Assuming that the variable has already been removed from non-zero weights
890 * Can we find a staged variable to add?
891 * If yes, check that none of the constraints that this variable is involved in is at the limit of its concurrency
892 * And then add it to enabled variables
894 void s_lmm_system_t::on_disabled_var(lmm_constraint_t cnstr)
896 if (cnstr->get_concurrency_limit() < 0)
899 int numelem = xbt_swag_size(&(cnstr->disabled_element_set));
903 lmm_element_t elem = (lmm_element_t)xbt_swag_getFirst(&(cnstr->disabled_element_set));
905 //Cannot use xbt_swag_foreach, because lmm_enable_var will modify disabled_element_set.. within the loop
906 while (numelem-- && elem) {
908 lmm_element_t nextelem = (lmm_element_t)xbt_swag_getNext(elem, cnstr->disabled_element_set.offset);
910 if (elem->variable->staged_weight > 0 && lmm_can_enable_var(elem->variable)) {
911 //Found a staged variable
912 //TODOLATER: Add random timing function to model reservation protocol fuzziness? Then how to make sure that
913 //staged variables will eventually be called?
914 enable_var(elem->variable);
917 xbt_assert(cnstr->concurrency_current <= cnstr->get_concurrency_limit(), "Concurrency overflow!");
918 if (cnstr->concurrency_current == cnstr->get_concurrency_limit())
924 //We could get an assertion fail, because transiently there can be variables that are staged and could be activated.
925 //And we need to go through all constraints of the disabled var before getting back a coherent state.
926 // Anyway, caller functions all call check_concurrency() in the end.
929 /* \brief update the weight of a variable, and enable/disable it.
930 * @return Returns whether a change was made
932 void s_lmm_system_t::update_variable_weight(lmm_variable_t var, double weight)
934 xbt_assert(weight>=0,"Variable weight should not be negative!");
936 if (weight == var->sharing_weight)
939 int enabling_var = (weight > 0 && var->sharing_weight <= 0);
940 int disabling_var = (weight <= 0 && var->sharing_weight > 0);
942 XBT_IN("(sys=%p, var=%p, weight=%f)", this, var, weight);
946 //Are we enabling this variable?
948 var->staged_weight = weight;
949 int minslack = lmm_cnstrs_min_concurrency_slack(var);
950 if (minslack < var->concurrency_share) {
951 XBT_DEBUG("Staging var (instead of enabling) because min concurrency slack %i, with weight %f and concurrency"
952 " share %i", minslack, weight, var->concurrency_share);
955 XBT_DEBUG("Enabling var with min concurrency slack %i", minslack);
957 } else if (disabling_var){
958 //Are we disabling this variable?
961 var->sharing_weight = weight;
969 double lmm_get_variable_weight(lmm_variable_t var)
971 return var->sharing_weight;
974 void s_lmm_system_t::update_constraint_bound(lmm_constraint_t cnst, double bound)
977 update_modified_set(cnst);
981 /** \brief Update the constraint set propagating recursively to other constraints so the system should not be entirely
984 * \param sys the lmm_system_t
985 * \param cnst the lmm_constraint_t affected by the change
987 * A recursive algorithm to optimize the system recalculation selecting only constraints that have changed. Each
988 * constraint change is propagated to the list of constraints for each variable.
990 void s_lmm_system_t::update_modified_set_rec(lmm_constraint_t cnst)
994 xbt_swag_foreach(_elem, &cnst->enabled_element_set) {
995 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
996 for (s_lmm_element_t const& elem : var->cnsts) {
997 if (var->visited == visited_counter)
999 if (elem.constraint != cnst && not xbt_swag_belongs(elem.constraint, &modified_constraint_set)) {
1000 xbt_swag_insert(elem.constraint, &modified_constraint_set);
1001 update_modified_set_rec(elem.constraint);
1004 //var will be ignored in later visits as long as sys->visited_counter does not move
1005 var->visited = visited_counter;
1009 void s_lmm_system_t::update_modified_set(lmm_constraint_t cnst)
1011 /* nothing to do if selective update isn't active */
1012 if (selective_update_active && not xbt_swag_belongs(cnst, &modified_constraint_set)) {
1013 xbt_swag_insert(cnst, &modified_constraint_set);
1014 update_modified_set_rec(cnst);
1018 void s_lmm_system_t::remove_all_modified_set()
1020 // We cleverly un-flag all variables just by incrementing visited_counter
1021 // In effect, the var->visited value will no more be equal to visited counter
1022 // To be clean, when visited counter has wrapped around, we force these var->visited values so that variables that
1023 // were in the modified a long long time ago are not wrongly skipped here, which would lead to very nasty bugs
1024 // (i.e. not readibily reproducible, and requiring a lot of run time before happening).
1025 if (++visited_counter == 1) {
1026 /* the counter wrapped around, reset each variable->visited */
1028 xbt_swag_foreach(_var, &variable_set)
1029 ((lmm_variable_t)_var)->visited = 0;
1031 xbt_swag_reset(&modified_constraint_set);
1035 * Returns resource load (in flop per second, or byte per second, or similar)
1037 * If the resource is shared (the default case), the load is sum of resource usage made by every variables located on
1040 * If the resource is not shared (ie in FATPIPE mode), then the load is the max (not the sum) of all resource usages
1041 * located on this resource.
1043 * \param cnst the lmm_constraint_t associated to the resource
1045 double s_lmm_constraint_t::get_usage() const
1048 const_xbt_swag_t elem_list = &enabled_element_set;
1051 xbt_swag_foreach(_elem, elem_list)
1053 lmm_element_t elem = (lmm_element_t)_elem;
1054 if (elem->consumption_weight > 0) {
1056 usage += elem->consumption_weight * elem->variable->value;
1057 else if (usage < elem->consumption_weight * elem->variable->value)
1058 usage = std::max(usage, elem->consumption_weight * elem->variable->value);
1064 int s_lmm_constraint_t::get_variable_amount() const
1067 const_xbt_swag_t elem_list = &enabled_element_set;
1070 xbt_swag_foreach(_elem, elem_list) {
1071 lmm_element_t elem = (lmm_element_t)_elem;
1072 if (elem->consumption_weight > 0)