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 void *lmm_variable_mallocator_new_f();
29 static void lmm_variable_mallocator_free_f(void *var);
30 #define lmm_variable_mallocator_reset_f ((void_f_pvoid_t)nullptr)
31 static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst);
32 static void lmm_remove_all_modified_set(lmm_system_t sys);
33 static int Global_debug_id = 1;
34 static int Global_const_debug_id = 1;
36 static inline void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst);
38 static void lmm_on_disabled_var(lmm_system_t sys, lmm_constraint_t cnstr);
39 static void lmm_enable_var(lmm_system_t sys, lmm_variable_t var);
40 static int lmm_can_enable_var(lmm_variable_t var);
41 static void lmm_disable_var(lmm_system_t sys, lmm_variable_t var);
42 static int lmm_concurrency_slack(lmm_constraint_t cnstr);
43 static int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var);
45 static inline int lmm_element_concurrency(lmm_element_t elem)
47 //Ignore element with weight less than one (e.g. cross-traffic)
48 return (elem->consumption_weight >= 1) ? 1 : 0;
49 //There are other alternatives, but they will change the behaviour of the model..
50 //So do not use it unless you want to make a new model.
51 //If you do, remember to change the variables concurrency share to reflect it.
52 //Potential examples are:
53 //return (elem->weight>0)?1:0;//Include element as soon as weight is non-zero
54 //return (int)ceil(elem->weight);//Include element as the rounded-up integer value of the element weight
57 static inline void lmm_decrease_concurrency(lmm_element_t elem)
59 xbt_assert(elem->constraint->concurrency_current>=lmm_element_concurrency(elem));
60 elem->constraint->concurrency_current-=lmm_element_concurrency(elem);
63 static inline void lmm_increase_concurrency(lmm_element_t elem)
65 elem->constraint->concurrency_current+= lmm_element_concurrency(elem);
67 lmm_constraint_t cnstr=elem->constraint;
69 if(cnstr->concurrency_current > cnstr->concurrency_maximum)
70 cnstr->concurrency_maximum= cnstr->concurrency_current;
72 xbt_assert(cnstr->concurrency_limit<0 || cnstr->concurrency_current<=cnstr->concurrency_limit,
73 "Concurrency limit overflow!");
76 static void lmm_check_concurrency(lmm_system_t sys)
78 // These checks are very expensive, so do them only if we want to debug SURF LMM
79 if (not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug))
83 xbt_swag_foreach(cnstIt, &(sys->constraint_set))
85 lmm_constraint_t cnst = (lmm_constraint_t)cnstIt;
88 xbt_swag_foreach(elemIt, &(cnst->enabled_element_set))
90 lmm_element_t elem = (lmm_element_t)elemIt;
91 xbt_assert(elem->variable->sharing_weight > 0);
92 concurrency += lmm_element_concurrency(elem);
95 xbt_swag_foreach(elemIt, &(cnst->disabled_element_set))
97 lmm_element_t elem = (lmm_element_t)elemIt;
98 // We should have staged variables only if concurrency is reached in some constraint
99 xbt_assert(cnst->concurrency_limit < 0 || elem->variable->staged_weight == 0 ||
100 lmm_cnstrs_min_concurrency_slack(elem->variable) < elem->variable->concurrency_share,
101 "should not have staged variable!");
104 xbt_assert(cnst->concurrency_limit < 0 || cnst->concurrency_limit >= concurrency, "concurrency check failed!");
105 xbt_assert(cnst->concurrency_current == concurrency, "concurrency_current is out-of-date!");
108 // Check that for each variable, all corresponding elements are in the same state (i.e. same element sets)
110 xbt_swag_foreach(varIt, &(sys->variable_set))
112 lmm_variable_t var = (lmm_variable_t)varIt;
114 if (var->cnsts.empty())
117 lmm_element_t elem = &var->cnsts[0];
118 int belong_to_enabled = xbt_swag_belongs(elem, &(elem->constraint->enabled_element_set));
119 int belong_to_disabled = xbt_swag_belongs(elem, &(elem->constraint->disabled_element_set));
120 int belong_to_active = xbt_swag_belongs(elem, &(elem->constraint->active_element_set));
122 for (s_lmm_element_t const& elem : var->cnsts) {
123 xbt_assert(belong_to_enabled == xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)),
124 "Variable inconsistency (1): enabled_element_set");
125 xbt_assert(belong_to_disabled == xbt_swag_belongs(&elem, &(elem.constraint->disabled_element_set)),
126 "Variable inconsistency (2): disabled_element_set");
127 xbt_assert(belong_to_active == xbt_swag_belongs(&elem, &(elem.constraint->active_element_set)),
128 "Variable inconsistency (3): active_element_set");
133 static void lmm_var_free(lmm_system_t sys, lmm_variable_t var)
135 XBT_IN("(sys=%p, var=%p)", sys, var);
138 // TODOLATER Can do better than that by leaving only the variable in only one enabled_element_set, call
139 // lmm_update_modified_set, and then remove it..
140 if (not var->cnsts.empty())
141 lmm_update_modified_set(sys, var->cnsts[0].constraint);
143 for (s_lmm_element_t& elem : var->cnsts) {
144 if (var->sharing_weight > 0)
145 lmm_decrease_concurrency(&elem);
146 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
147 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
148 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
149 int nelements = xbt_swag_size(&(elem.constraint->enabled_element_set)) +
150 xbt_swag_size(&(elem.constraint->disabled_element_set));
152 make_constraint_inactive(sys, elem.constraint);
154 lmm_on_disabled_var(sys, elem.constraint);
159 lmm_check_concurrency(sys);
161 xbt_mallocator_release(sys->variable_mallocator, var);
165 lmm_system_t lmm_system_new(bool selective_update)
167 s_lmm_variable_t var;
168 s_lmm_constraint_t cnst;
170 lmm_system_t l = new s_lmm_system_t();
173 l->selective_update_active = selective_update;
174 l->visited_counter = 1;
176 XBT_DEBUG("Setting selective_update_active flag to %d", l->selective_update_active);
178 xbt_swag_init(&(l->variable_set), xbt_swag_offset(var, variable_set_hookup));
179 xbt_swag_init(&(l->constraint_set), xbt_swag_offset(cnst, constraint_set_hookup));
181 xbt_swag_init(&(l->active_constraint_set), xbt_swag_offset(cnst, active_constraint_set_hookup));
183 xbt_swag_init(&(l->modified_constraint_set), xbt_swag_offset(cnst, modified_constraint_set_hookup));
184 xbt_swag_init(&(l->saturated_variable_set), xbt_swag_offset(var, saturated_variable_set_hookup));
185 xbt_swag_init(&(l->saturated_constraint_set), xbt_swag_offset(cnst, saturated_constraint_set_hookup));
187 l->variable_mallocator = xbt_mallocator_new(65536,
188 lmm_variable_mallocator_new_f,
189 lmm_variable_mallocator_free_f,
190 lmm_variable_mallocator_reset_f);
192 l->solve_fun = &lmm_solve;
197 void lmm_system_free(lmm_system_t sys)
199 lmm_variable_t var = nullptr;
200 lmm_constraint_t cnst = nullptr;
205 while ((var = (lmm_variable_t) extract_variable(sys))) {
206 auto demangled = simgrid::xbt::demangle(typeid(*var->id).name());
207 XBT_WARN("Probable bug: a %s variable (#%d) not removed before the LMM system destruction.", demangled.get(),
209 lmm_var_free(sys, var);
211 while ((cnst = (lmm_constraint_t) extract_constraint(sys)))
212 lmm_cnst_free(sys, cnst);
214 xbt_mallocator_free(sys->variable_mallocator);
218 static inline void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst)
220 make_constraint_inactive(sys, cnst);
224 lmm_constraint_t lmm_constraint_new(lmm_system_t sys, void *id, double bound_value)
226 lmm_constraint_t cnst = nullptr;
227 s_lmm_element_t elem;
229 cnst = new s_lmm_constraint_t();
231 cnst->id_int = Global_const_debug_id++;
232 xbt_swag_init(&(cnst->enabled_element_set), xbt_swag_offset(elem, enabled_element_set_hookup));
233 xbt_swag_init(&(cnst->disabled_element_set), xbt_swag_offset(elem, disabled_element_set_hookup));
234 xbt_swag_init(&(cnst->active_element_set), xbt_swag_offset(elem, active_element_set_hookup));
236 cnst->bound = bound_value;
237 cnst->concurrency_maximum=0;
238 cnst->concurrency_current=0;
239 cnst->concurrency_limit = sg_concurrency_limit;
241 cnst->sharing_policy = 1; /* FIXME: don't hardcode the value */
242 insert_constraint(sys, cnst);
247 int lmm_constraint_concurrency_limit_get(lmm_constraint_t cnst)
249 return cnst->concurrency_limit;
252 void lmm_constraint_concurrency_limit_set(lmm_constraint_t cnst, int concurrency_limit)
254 xbt_assert(concurrency_limit<0 || cnst->concurrency_maximum<=concurrency_limit,
255 "New concurrency limit should be larger than observed concurrency maximum. Maybe you want to call"
256 " lmm_constraint_concurrency_maximum_reset() to reset the maximum?");
257 cnst->concurrency_limit = concurrency_limit;
260 void lmm_constraint_concurrency_maximum_reset(lmm_constraint_t cnst)
262 cnst->concurrency_maximum = 0;
265 int lmm_constraint_concurrency_maximum_get(lmm_constraint_t cnst)
267 xbt_assert(cnst->concurrency_limit<0 || cnst->concurrency_maximum<=cnst->concurrency_limit,
268 "Very bad: maximum observed concurrency is higher than limit. This is a bug of SURF, please report it.");
269 return cnst->concurrency_maximum;
272 void lmm_constraint_shared(lmm_constraint_t cnst)
274 cnst->sharing_policy = 0;
277 /** Return true if the constraint is shared, and false if it's FATPIPE */
278 int lmm_constraint_sharing_policy(lmm_constraint_t cnst)
280 return (cnst->sharing_policy);
283 static void *lmm_variable_mallocator_new_f()
285 return new s_lmm_variable_t;
288 static void lmm_variable_mallocator_free_f(void *var)
290 delete static_cast<lmm_variable_t>(var);
293 lmm_variable_t lmm_variable_new(lmm_system_t sys, simgrid::surf::Action* id, double sharing_weight, double bound,
294 int number_of_constraints)
296 XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)", sys, id, sharing_weight, bound, number_of_constraints);
298 lmm_variable_t var = (lmm_variable_t)xbt_mallocator_get(sys->variable_mallocator);
300 var->id_int = Global_debug_id++;
301 var->cnsts.reserve(number_of_constraints);
302 var->sharing_weight = sharing_weight;
303 var->staged_weight = 0.0;
305 var->concurrency_share = 1;
307 var->visited = sys->visited_counter - 1;
310 var->func_f = func_f_def;
311 var->func_fp = func_fp_def;
312 var->func_fpi = func_fpi_def;
314 var->variable_set_hookup.next = nullptr;
315 var->variable_set_hookup.prev = nullptr;
316 var->saturated_variable_set_hookup.next = nullptr;
317 var->saturated_variable_set_hookup.prev = nullptr;
320 xbt_swag_insert_at_head(var, &(sys->variable_set));
322 xbt_swag_insert_at_tail(var, &(sys->variable_set));
324 XBT_OUT(" returns %p", var);
328 void lmm_variable_free(lmm_system_t sys, lmm_variable_t var)
330 remove_variable(sys, var);
331 lmm_var_free(sys, var);
334 double lmm_variable_getvalue(lmm_variable_t var)
339 void lmm_variable_concurrency_share_set(lmm_variable_t var, short int concurrency_share)
341 var->concurrency_share=concurrency_share;
344 double lmm_variable_getbound(lmm_variable_t var)
349 void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst, lmm_variable_t var, double consumption_weight)
353 //Check if this variable already has an active element in this constraint
354 //If it does, substract it from the required slack
355 int current_share = 0;
356 if(var->concurrency_share>1){
357 for (s_lmm_element_t& elem : var->cnsts) {
358 if (elem.constraint == cnst && xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)))
359 current_share += lmm_element_concurrency(&elem);
363 //Check if we need to disable the variable
364 if (var->sharing_weight > 0 && var->concurrency_share - current_share > lmm_concurrency_slack(cnst)) {
365 double weight = var->sharing_weight;
366 lmm_disable_var(sys,var);
367 for (s_lmm_element_t const& elem : var->cnsts)
368 lmm_on_disabled_var(sys, elem.constraint);
369 consumption_weight = 0;
370 var->staged_weight=weight;
371 xbt_assert(not var->sharing_weight);
374 xbt_assert(var->cnsts.size() < var->cnsts.capacity(), "Too much constraints");
376 var->cnsts.resize(var->cnsts.size() + 1);
377 s_lmm_element_t& elem = var->cnsts.back();
379 elem.consumption_weight = consumption_weight;
380 elem.constraint = cnst;
383 if (var->sharing_weight) {
384 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
385 lmm_increase_concurrency(&elem);
387 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
389 if (not sys->selective_update_active) {
390 make_constraint_active(sys, cnst);
391 } else if (elem.consumption_weight > 0 || var->sharing_weight > 0) {
392 make_constraint_active(sys, cnst);
393 lmm_update_modified_set(sys, cnst);
394 //TODOLATER: Why do we need this second call?
395 if (var->cnsts.size() > 1)
396 lmm_update_modified_set(sys, var->cnsts[0].constraint);
399 lmm_check_concurrency(sys);
402 void lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst, lmm_variable_t var, double value)
406 lmm_check_concurrency(sys);
408 //BEWARE: In case you have multiple elements in one constraint, this will always add value to the first element.
409 auto elem_it = std::find_if(begin(var->cnsts), end(var->cnsts),
410 [&cnst](s_lmm_element_t const& x) { return x.constraint == cnst; });
411 if (elem_it != end(var->cnsts)) {
412 s_lmm_element_t& elem = *elem_it;
413 if (var->sharing_weight)
414 lmm_decrease_concurrency(&elem);
416 if (cnst->sharing_policy)
417 elem.consumption_weight += value;
419 elem.consumption_weight = std::max(elem.consumption_weight, value);
421 //We need to check that increasing value of the element does not cross the concurrency limit
422 if (var->sharing_weight) {
423 if (lmm_concurrency_slack(cnst) < lmm_element_concurrency(&elem)) {
424 double weight = var->sharing_weight;
425 lmm_disable_var(sys,var);
426 for (s_lmm_element_t const& elem2 : var->cnsts)
427 lmm_on_disabled_var(sys, elem2.constraint);
428 var->staged_weight=weight;
429 xbt_assert(not var->sharing_weight);
431 lmm_increase_concurrency(&elem);
433 lmm_update_modified_set(sys, cnst);
435 lmm_expand(sys, cnst, var, value);
437 lmm_check_concurrency(sys);
440 lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
442 if (num < var->cnsts.size())
443 return (var->cnsts[num].constraint);
448 double lmm_get_cnst_weight_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
450 if (num < var->cnsts.size())
451 return (var->cnsts[num].consumption_weight);
456 int lmm_get_number_of_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var)
458 return (var->cnsts.size());
461 lmm_variable_t lmm_get_var_from_cnst(lmm_system_t /*sys*/, lmm_constraint_t cnst, lmm_element_t * elem)
463 if (*elem == nullptr) {
464 // That is the first call, pick the first element among enabled_element_set (or disabled_element_set if
465 // enabled_element_set is empty)
466 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->enabled_element_set));
467 if (*elem == nullptr)
468 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
470 //elem is not null, so we carry on
471 if(xbt_swag_belongs(*elem,&(cnst->enabled_element_set))){
472 //Look at enabled_element_set, and jump to disabled_element_set when finished
473 *elem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->enabled_element_set.offset);
474 if (*elem == nullptr)
475 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
477 *elem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->disabled_element_set.offset);
481 return (*elem)->variable;
486 //if we modify the swag between calls, normal version may loop forever
487 //this safe version ensures that we browse the swag elements only once
488 lmm_variable_t lmm_get_var_from_cnst_safe(lmm_system_t /*sys*/, lmm_constraint_t cnst, lmm_element_t * elem,
489 lmm_element_t * nextelem, int * numelem)
491 if (*elem == nullptr) {
492 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->enabled_element_set));
493 *numelem = xbt_swag_size(&(cnst->enabled_element_set))+xbt_swag_size(&(cnst->disabled_element_set))-1;
494 if (*elem == nullptr)
495 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
504 //elem is not null, so we carry on
505 if(xbt_swag_belongs(*elem,&(cnst->enabled_element_set))){
506 //Look at enabled_element_set, and jump to disabled_element_set when finished
507 *nextelem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->enabled_element_set.offset);
508 if (*nextelem == nullptr)
509 *nextelem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
511 *nextelem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->disabled_element_set.offset);
513 return (*elem)->variable;
518 void *lmm_constraint_id(lmm_constraint_t cnst)
523 void *lmm_variable_id(lmm_variable_t var)
528 static inline void saturated_constraint_set_update(double usage, int cnst_light_num,
529 dyn_light_t& saturated_constraint_set, double* min_usage)
531 xbt_assert(usage > 0,"Impossible");
533 if (*min_usage < 0 || *min_usage > usage) {
535 XBT_HERE(" min_usage=%f (cnst->remaining / cnst->usage =%f)", *min_usage, usage);
536 saturated_constraint_set.assign(1, cnst_light_num);
537 } else if (*min_usage == usage) {
538 saturated_constraint_set.emplace_back(cnst_light_num);
542 static inline void saturated_variable_set_update(s_lmm_constraint_light_t* cnst_light_tab,
543 const dyn_light_t& saturated_constraint_set, lmm_system_t sys)
545 /* Add active variables (i.e. variables that need to be set) from the set of constraints to saturate (cnst_light_tab)*/
546 for (int const& saturated_cnst : saturated_constraint_set) {
547 lmm_constraint_light_t cnst = &cnst_light_tab[saturated_cnst];
549 xbt_swag_t elem_list = &(cnst->cnst->active_element_set);
550 xbt_swag_foreach(_elem, elem_list) {
551 lmm_element_t elem = (lmm_element_t)_elem;
552 //Visiting active_element_set, so, by construction, should never get a zero weight, correct?
553 xbt_assert(elem->variable->sharing_weight > 0);
554 if (elem->consumption_weight > 0)
555 xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
560 void lmm_print(lmm_system_t sys)
562 std::string buf = std::string("MAX-MIN ( ");
565 /* Printing Objective */
566 xbt_swag_t var_list = &(sys->variable_set);
567 xbt_swag_foreach(_var, var_list) {
568 lmm_variable_t var = (lmm_variable_t)_var;
569 buf = buf + "'" + std::to_string(var->id_int) + "'(" + std::to_string(var->sharing_weight) + ") ";
572 XBT_DEBUG("%20s", buf.c_str());
575 XBT_DEBUG("Constraints");
576 /* Printing Constraints */
578 xbt_swag_t cnst_list = &(sys->active_constraint_set);
579 xbt_swag_foreach(_cnst, cnst_list) {
580 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
582 //Show the enabled variables
584 xbt_swag_t elem_list = &(cnst->enabled_element_set);
586 buf += ((cnst->sharing_policy) ? "(" : "max(");
587 xbt_swag_foreach(_elem, elem_list) {
588 lmm_element_t elem = (lmm_element_t)_elem;
589 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
590 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
591 if(cnst->sharing_policy)
592 sum += elem->consumption_weight * elem->variable->value;
594 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
596 //TODO: Adding disabled elements only for test compatibility, but do we really want them to be printed?
597 elem_list = &(cnst->disabled_element_set);
598 xbt_swag_foreach(_elem, elem_list) {
599 lmm_element_t elem = (lmm_element_t)_elem;
600 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
601 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
602 if(cnst->sharing_policy)
603 sum += elem->consumption_weight * elem->variable->value;
605 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
608 buf = buf + "0) <= " + std::to_string(cnst->bound) + " ('" + std::to_string(cnst->id_int) + "')";
610 if (not cnst->sharing_policy) {
611 buf += " [MAX-Constraint]";
613 XBT_DEBUG("%s", buf.c_str());
615 xbt_assert(not double_positive(sum - cnst->bound, cnst->bound * sg_maxmin_precision),
616 "Incorrect value (%f is not smaller than %f): %g", sum, cnst->bound, sum - cnst->bound);
619 XBT_DEBUG("Variables");
620 /* Printing Result */
621 xbt_swag_foreach(_var, var_list) {
622 lmm_variable_t var = (lmm_variable_t)_var;
623 if (var->bound > 0) {
624 XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->sharing_weight, var->value, var->bound);
625 xbt_assert(not double_positive(var->value - var->bound, var->bound * sg_maxmin_precision),
626 "Incorrect value (%f is not smaller than %f", var->value, var->bound);
628 XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->sharing_weight, var->value);
633 void lmm_solve(lmm_system_t sys)
638 double min_usage = -1;
639 double min_bound = -1;
641 if (not sys->modified)
644 XBT_IN("(sys=%p)", sys);
646 /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only constraints
647 * that changed are considered. Otherwise all constraints with active actions are considered.
649 xbt_swag_t cnst_list = sys->selective_update_active ? &(sys->modified_constraint_set) : &(sys->active_constraint_set);
651 XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
652 /* Init: Only modified code portions: reset the value of active variables */
653 xbt_swag_foreach(_cnst, cnst_list) {
654 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
655 xbt_swag_t elem_list = &(cnst->enabled_element_set);
656 xbt_swag_foreach(_elem, elem_list) {
657 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
658 xbt_assert(var->sharing_weight > 0.0);
663 s_lmm_constraint_light_t* cnst_light_tab = new s_lmm_constraint_light_t[xbt_swag_size(cnst_list)]();
664 int cnst_light_num = 0;
665 dyn_light_t saturated_constraint_set;
667 xbt_swag_foreach_safe(_cnst, _cnst_next, cnst_list) {
668 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
669 /* INIT: Collect constraints that actually need to be saturated (i.e remaining and usage are strictly positive)
670 * into cnst_light_tab. */
671 cnst->remaining = cnst->bound;
672 if (not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision))
675 xbt_swag_t elem_list = &(cnst->enabled_element_set);
676 xbt_swag_foreach(_elem, elem_list) {
677 lmm_element_t elem = (lmm_element_t)_elem;
678 xbt_assert(elem->variable->sharing_weight > 0);
679 if (elem->consumption_weight > 0) {
680 if (cnst->sharing_policy)
681 cnst->usage += elem->consumption_weight / elem->variable->sharing_weight;
682 else if (cnst->usage < elem->consumption_weight / elem->variable->sharing_weight)
683 cnst->usage = elem->consumption_weight / elem->variable->sharing_weight;
685 make_elem_active(elem);
686 simgrid::surf::Action *action = static_cast<simgrid::surf::Action*>(elem->variable->id);
687 if (sys->keep_track && not action->is_linked())
688 sys->keep_track->push_back(*action);
691 XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst->id_int, cnst->usage,
692 cnst->remaining,cnst->concurrency_current,cnst->concurrency_maximum,cnst->concurrency_limit);
693 /* Saturated constraints update */
695 if(cnst->usage > 0) {
696 cnst_light_tab[cnst_light_num].cnst = cnst;
697 cnst->cnst_light = &(cnst_light_tab[cnst_light_num]);
698 cnst_light_tab[cnst_light_num].remaining_over_usage = cnst->remaining / cnst->usage;
699 saturated_constraint_set_update(cnst_light_tab[cnst_light_num].remaining_over_usage,
700 cnst_light_num, saturated_constraint_set, &min_usage);
701 xbt_assert(cnst->active_element_set.count>0, "There is no sense adding a constraint that has no active element!");
706 saturated_variable_set_update( cnst_light_tab, saturated_constraint_set, sys);
708 /* Saturated variables update */
710 /* Fix the variables that have to be */
711 xbt_swag_t var_list = &(sys->saturated_variable_set);
713 lmm_variable_t var = nullptr;
714 xbt_swag_foreach(_var, var_list) {
715 var = (lmm_variable_t)_var;
716 if (var->sharing_weight <= 0.0)
718 /* First check if some of these variables could reach their upper bound and update min_bound accordingly. */
719 XBT_DEBUG("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f", var->id_int,
720 var->bound, var->sharing_weight, min_usage, var->bound * var->sharing_weight);
721 if ((var->bound > 0) && (var->bound * var->sharing_weight < min_usage)) {
723 min_bound = var->bound * var->sharing_weight;
725 min_bound = std::min(min_bound, (var->bound * var->sharing_weight));
726 XBT_DEBUG("Updated min_bound=%f", min_bound);
730 while ((var = (lmm_variable_t)xbt_swag_getFirst(var_list))) {
732 //If no variable could reach its bound, deal iteratively the constraints usage ( at worst one constraint is
733 // saturated at each cycle)
734 var->value = min_usage / var->sharing_weight;
735 XBT_DEBUG("Setting var (%d) value to %f\n", var->id_int, var->value);
737 //If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
738 if (double_equals(min_bound, var->bound * var->sharing_weight, sg_maxmin_precision)) {
739 var->value = var->bound;
740 XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
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);
748 XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ", min_usage, var->id_int, var->sharing_weight,
749 var->id_int, var->value);
751 /* Update the usage of contraints where this variable is involved */
752 for (s_lmm_element_t& elem : var->cnsts) {
753 lmm_constraint_t cnst = elem.constraint;
754 if (cnst->sharing_policy) {
755 // Remember: shared constraints require that sum(elem.value * var->value) < cnst->bound
756 double_update(&(cnst->remaining), elem.consumption_weight * var->value, cnst->bound * sg_maxmin_precision);
757 double_update(&(cnst->usage), elem.consumption_weight / var->sharing_weight, sg_maxmin_precision);
758 // If the constraint is saturated, remove it from the set of active constraints (light_tab)
759 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
760 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
761 if (cnst->cnst_light) {
762 int index = (cnst->cnst_light-cnst_light_tab);
763 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f ",
764 index,cnst_light_num, cnst->usage, cnst->remaining, cnst->bound);
765 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
766 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
768 cnst->cnst_light = nullptr;
771 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
773 make_elem_inactive(&elem);
775 // Remember: non-shared constraints only require that max(elem.value * var->value) < cnst->bound
777 make_elem_inactive(&elem);
778 xbt_swag_t elem_list = &(cnst->enabled_element_set);
779 xbt_swag_foreach(_elem, elem_list) {
780 lmm_element_t elem2 = static_cast<lmm_element_t>(_elem);
781 xbt_assert(elem2->variable->sharing_weight > 0);
782 if (elem2->variable->value > 0)
784 if (elem2->consumption_weight > 0)
785 cnst->usage = std::max(cnst->usage, elem2->consumption_weight / elem2->variable->sharing_weight);
787 //If the constraint is saturated, remove it from the set of active constraints (light_tab)
788 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
789 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
790 if(cnst->cnst_light) {
791 int index = (cnst->cnst_light-cnst_light_tab);
792 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
793 "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f ", index,cnst_light_num, cnst,
794 cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining, cnst->bound);
795 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
796 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
798 cnst->cnst_light = nullptr;
801 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
802 xbt_assert(cnst->active_element_set.count>0, "Should not keep a maximum constraint that has no active"
803 " element! You want to check the maxmin precision and possible rounding effects." );
807 xbt_swag_remove(var, var_list);
810 /* Find out which variables reach the maximum */
813 saturated_constraint_set.clear();
815 for(pos=0; pos<cnst_light_num; pos++){
816 xbt_assert(cnst_light_tab[pos].cnst->active_element_set.count>0, "Cannot saturate more a constraint that has"
817 " no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>)"
818 " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
819 "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
820 cnst_light_tab[pos].cnst->usage, sg_maxmin_precision, cnst_light_tab[pos-1].cnst->usage);
821 saturated_constraint_set_update(cnst_light_tab[pos].remaining_over_usage, pos, saturated_constraint_set,
825 saturated_variable_set_update(cnst_light_tab, saturated_constraint_set, sys);
827 } while (cnst_light_num > 0);
830 if (sys->selective_update_active)
831 lmm_remove_all_modified_set(sys);
833 if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
837 lmm_check_concurrency(sys);
839 delete[] cnst_light_tab;
843 /** \brief Attribute the value bound to var->bound.
845 * \param sys the lmm_system_t
846 * \param var the lmm_variable_t
847 * \param bound the new bound to associate with var
849 * Makes var->bound equal to bound. Whenever this function is called a change is signed in the system. To
850 * avoid false system changing detection it is a good idea to test (bound != 0) before calling it.
852 void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var, double bound)
857 if (not var->cnsts.empty())
858 lmm_update_modified_set(sys, var->cnsts[0].constraint);
861 int lmm_concurrency_slack(lmm_constraint_t cnstr)
863 if (cnstr->concurrency_limit < 0)
864 return std::numeric_limits<int>::max();
865 return cnstr->concurrency_limit - cnstr->concurrency_current;
868 /** \brief Measure the minimum concurrency slack across all constraints where the given var is involved */
869 int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var)
871 int minslack = std::numeric_limits<int>::max();
872 for (s_lmm_element_t const& elem : var->cnsts) {
873 int slack = lmm_concurrency_slack(elem.constraint);
874 if (slack < minslack) {
875 // This is only an optimization, to avoid looking at more constraints when slack is already zero
884 /* /Check if a variable can be enabled
886 * Make sure to set staged_weight before, if your intent is only to check concurrency
888 int lmm_can_enable_var(lmm_variable_t var){
889 return var->staged_weight>0 && lmm_cnstrs_min_concurrency_slack(var)>=var->concurrency_share;
892 //Small remark: In this implementation of lmm_enable_var and lmm_disable_var, we will meet multiple times with var when
893 // running lmm_update_modified_set.
894 //A priori not a big performance issue, but we might do better by calling lmm_update_modified_set within the for loops
895 // (after doing the first for enabling==1, and before doing the last for disabling==1)
896 void lmm_enable_var(lmm_system_t sys, lmm_variable_t var){
897 xbt_assert(not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug) || lmm_can_enable_var(var));
899 var->sharing_weight = var->staged_weight;
900 var->staged_weight = 0;
902 // Enabling the variable, move to var to list head. Subtlety is: here, we need to call lmm_update_modified_set AFTER
903 // moving at least one element of var.
905 xbt_swag_remove(var, &(sys->variable_set));
906 xbt_swag_insert_at_head(var, &(sys->variable_set));
907 for (s_lmm_element_t& elem : var->cnsts) {
908 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
909 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
910 lmm_increase_concurrency(&elem);
912 if (not var->cnsts.empty())
913 lmm_update_modified_set(sys, var->cnsts[0].constraint);
915 //When used within lmm_on_disabled_var, we would get an assertion fail, because transiently there can be variables
916 // that are staged and could be activated.
917 //Anyway, caller functions all call lmm_check_concurrency() in the end.
920 void lmm_disable_var(lmm_system_t sys, lmm_variable_t var){
921 xbt_assert(not var->staged_weight, "Staged weight should have been cleared");
922 // Disabling the variable, move to var to list tail. Subtlety is: here, we need to call lmm_update_modified_set BEFORE
923 // moving the last element of var.
924 xbt_swag_remove(var, &(sys->variable_set));
925 xbt_swag_insert_at_tail(var, &(sys->variable_set));
926 if (not var->cnsts.empty())
927 lmm_update_modified_set(sys, var->cnsts[0].constraint);
928 for (s_lmm_element_t& elem : var->cnsts) {
929 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
930 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
932 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
934 lmm_decrease_concurrency(&elem);
937 var->sharing_weight = 0.0;
938 var->staged_weight=0.0;
940 lmm_check_concurrency(sys);
943 /* /brief Find variables that can be enabled and enable them.
945 * Assuming that the variable has already been removed from non-zero weights
946 * Can we find a staged variable to add?
947 * If yes, check that none of the constraints that this variable is involved in is at the limit of its concurrency
948 * And then add it to enabled variables
950 void lmm_on_disabled_var(lmm_system_t sys, lmm_constraint_t cnstr){
952 if(cnstr->concurrency_limit<0)
955 int numelem = xbt_swag_size(&(cnstr->disabled_element_set));
959 lmm_element_t elem = (lmm_element_t)xbt_swag_getFirst(&(cnstr->disabled_element_set));
961 //Cannot use xbt_swag_foreach, because lmm_enable_var will modify disabled_element_set.. within the loop
962 while (numelem-- && elem) {
964 lmm_element_t nextelem = (lmm_element_t)xbt_swag_getNext(elem, cnstr->disabled_element_set.offset);
966 if (elem->variable->staged_weight > 0 && lmm_can_enable_var(elem->variable)) {
967 //Found a staged variable
968 //TODOLATER: Add random timing function to model reservation protocol fuzziness? Then how to make sure that
969 //staged variables will eventually be called?
970 lmm_enable_var(sys, elem->variable);
973 xbt_assert(cnstr->concurrency_current<=cnstr->concurrency_limit,"Concurrency overflow!");
974 if(cnstr->concurrency_current==cnstr->concurrency_limit)
980 //We could get an assertion fail, because transiently there can be variables that are staged and could be activated.
981 //And we need to go through all constraints of the disabled var before getting back a coherent state.
982 //Anyway, caller functions all call lmm_check_concurrency() in the end.
985 /* \brief update the weight of a variable, and enable/disable it.
986 * @return Returns whether a change was made
988 void lmm_update_variable_weight(lmm_system_t sys, lmm_variable_t var, double weight)
990 xbt_assert(weight>=0,"Variable weight should not be negative!");
992 if (weight == var->sharing_weight)
995 int enabling_var = (weight > 0 && var->sharing_weight <= 0);
996 int disabling_var = (weight <= 0 && var->sharing_weight > 0);
998 XBT_IN("(sys=%p, var=%p, weight=%f)", sys, var, weight);
1002 //Are we enabling this variable?
1004 var->staged_weight = weight;
1005 int minslack = lmm_cnstrs_min_concurrency_slack(var);
1006 if (minslack < var->concurrency_share) {
1007 XBT_DEBUG("Staging var (instead of enabling) because min concurrency slack %i, with weight %f and concurrency"
1008 " share %i", minslack, weight, var->concurrency_share);
1011 XBT_DEBUG("Enabling var with min concurrency slack %i", minslack);
1012 lmm_enable_var(sys,var);
1013 } else if (disabling_var){
1014 //Are we disabling this variable?
1015 lmm_disable_var(sys,var);
1017 var->sharing_weight = weight;
1020 lmm_check_concurrency(sys);
1025 double lmm_get_variable_weight(lmm_variable_t var)
1027 return var->sharing_weight;
1030 void lmm_update_constraint_bound(lmm_system_t sys, lmm_constraint_t cnst, double bound)
1033 lmm_update_modified_set(sys, cnst);
1034 cnst->bound = bound;
1037 int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
1039 return xbt_swag_belongs(cnst, &(sys->active_constraint_set));
1042 /** \brief Update the constraint set propagating recursively to other constraints so the system should not be entirely
1045 * \param sys the lmm_system_t
1046 * \param cnst the lmm_constraint_t affected by the change
1048 * A recursive algorithm to optimize the system recalculation selecting only constraints that have changed. Each
1049 * constraint change is propagated to the list of constraints for each variable.
1051 static void lmm_update_modified_set_rec(lmm_system_t sys, lmm_constraint_t cnst)
1055 xbt_swag_foreach(_elem, &cnst->enabled_element_set) {
1056 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
1057 for (s_lmm_element_t const& elem : var->cnsts) {
1058 if (var->visited == sys->visited_counter)
1060 if (elem.constraint != cnst && not xbt_swag_belongs(elem.constraint, &sys->modified_constraint_set)) {
1061 xbt_swag_insert(elem.constraint, &sys->modified_constraint_set);
1062 lmm_update_modified_set_rec(sys, elem.constraint);
1065 //var will be ignored in later visits as long as sys->visited_counter does not move
1066 var->visited = sys->visited_counter;
1070 static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst)
1072 /* nothing to do if selective update isn't active */
1073 if (sys->selective_update_active && not xbt_swag_belongs(cnst, &sys->modified_constraint_set)) {
1074 xbt_swag_insert(cnst, &sys->modified_constraint_set);
1075 lmm_update_modified_set_rec(sys, cnst);
1079 /** \brief Remove all constraints of the modified_constraint_set.
1081 * \param sys the lmm_system_t
1083 static void lmm_remove_all_modified_set(lmm_system_t sys)
1085 // We cleverly un-flag all variables just by incrementing sys->visited_counter
1086 // In effect, the var->visited value will no more be equal to sys->visited counter
1087 // To be clean, when visited counter has wrapped around, we force these var->visited values so that variables that
1088 // were in the modified a long long time ago are not wrongly skipped here, which would lead to very nasty bugs
1089 // (i.e. not readibily reproducible, and requiring a lot of run time before happening).
1090 if (++sys->visited_counter == 1) {
1091 /* the counter wrapped around, reset each variable->visited */
1093 xbt_swag_foreach(_var, &sys->variable_set)
1094 ((lmm_variable_t)_var)->visited = 0;
1096 xbt_swag_reset(&sys->modified_constraint_set);
1100 * Returns resource load (in flop per second, or byte per second, or similar)
1102 * If the resource is shared (the default case), the load is sum of resource usage made by every variables located on
1105 * If the resource is not shared (ie in FATPIPE mode), then the load is the max (not the sum) of all resource usages
1106 * located on this resource.
1108 * \param cnst the lmm_constraint_t associated to the resource
1110 double lmm_constraint_get_usage(lmm_constraint_t cnst) {
1112 xbt_swag_t elem_list = &(cnst->enabled_element_set);
1115 xbt_swag_foreach(_elem, elem_list)
1117 lmm_element_t elem = (lmm_element_t)_elem;
1118 if (elem->consumption_weight > 0) {
1119 if (cnst->sharing_policy)
1120 usage += elem->consumption_weight * elem->variable->value;
1121 else if (usage < elem->consumption_weight * elem->variable->value)
1122 usage = std::max(usage, elem->consumption_weight * elem->variable->value);
1128 int lmm_constraint_get_variable_amount(lmm_constraint_t cnst) {
1130 xbt_swag_t elem_list = &(cnst->enabled_element_set);
1133 xbt_swag_foreach(_elem, elem_list) {
1134 lmm_element_t elem = (lmm_element_t)_elem;
1135 if (elem->consumption_weight > 0)