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"
10 #include "xbt/mallocator.h"
11 #include "xbt/sysdep.h"
19 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_maxmin, surf, "Logging specific to SURF (maxmin)");
21 typedef std::vector<int> dyn_light_t;
23 double sg_maxmin_precision = 0.00001; /* Change this with --cfg=maxmin/precision:VALUE */
24 double sg_surf_precision = 0.00001; /* Change this with --cfg=surf/precision:VALUE */
25 int sg_concurrency_limit = -1; /* Change this with --cfg=maxmin/concurrency-limit:VALUE */
27 static void *lmm_variable_mallocator_new_f();
28 static void lmm_variable_mallocator_free_f(void *var);
29 #define lmm_variable_mallocator_reset_f ((void_f_pvoid_t)nullptr)
30 static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst);
31 static void lmm_remove_all_modified_set(lmm_system_t sys);
32 static int Global_debug_id = 1;
33 static int Global_const_debug_id = 1;
35 static inline void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst);
37 static void lmm_on_disabled_var(lmm_system_t sys, lmm_constraint_t cnstr);
38 static void lmm_enable_var(lmm_system_t sys, lmm_variable_t var);
39 static int lmm_can_enable_var(lmm_variable_t var);
40 static void lmm_disable_var(lmm_system_t sys, lmm_variable_t var);
41 static int lmm_concurrency_slack(lmm_constraint_t cnstr);
42 static int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var);
44 static inline int lmm_element_concurrency(lmm_element_t elem)
46 //Ignore element with weight less than one (e.g. cross-traffic)
47 return (elem->consumption_weight >= 1) ? 1 : 0;
48 //There are other alternatives, but they will change the behaviour of the model..
49 //So do not use it unless you want to make a new model.
50 //If you do, remember to change the variables concurrency share to reflect it.
51 //Potential examples are:
52 //return (elem->weight>0)?1:0;//Include element as soon as weight is non-zero
53 //return (int)ceil(elem->weight);//Include element as the rounded-up integer value of the element weight
56 static inline void lmm_decrease_concurrency(lmm_element_t elem)
58 xbt_assert(elem->constraint->concurrency_current>=lmm_element_concurrency(elem));
59 elem->constraint->concurrency_current-=lmm_element_concurrency(elem);
62 static inline void lmm_increase_concurrency(lmm_element_t elem)
64 elem->constraint->concurrency_current+= lmm_element_concurrency(elem);
66 lmm_constraint_t cnstr=elem->constraint;
68 if(cnstr->concurrency_current > cnstr->concurrency_maximum)
69 cnstr->concurrency_maximum= cnstr->concurrency_current;
71 xbt_assert(cnstr->concurrency_limit<0 || cnstr->concurrency_current<=cnstr->concurrency_limit,
72 "Concurrency limit overflow!");
75 static void lmm_check_concurrency(lmm_system_t sys)
77 // These checks are very expensive, so do them only if we want to debug SURF LMM
78 if (not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug))
82 xbt_swag_foreach(cnstIt, &(sys->constraint_set))
84 lmm_constraint_t cnst = (lmm_constraint_t)cnstIt;
87 xbt_swag_foreach(elemIt, &(cnst->enabled_element_set))
89 lmm_element_t elem = (lmm_element_t)elemIt;
90 xbt_assert(elem->variable->sharing_weight > 0);
91 concurrency += lmm_element_concurrency(elem);
94 xbt_swag_foreach(elemIt, &(cnst->disabled_element_set))
96 lmm_element_t elem = (lmm_element_t)elemIt;
97 // We should have staged variables only if concurrency is reached in some constraint
98 xbt_assert(cnst->concurrency_limit < 0 || elem->variable->staged_weight == 0 ||
99 lmm_cnstrs_min_concurrency_slack(elem->variable) < elem->variable->concurrency_share,
100 "should not have staged variable!");
103 xbt_assert(cnst->concurrency_limit < 0 || cnst->concurrency_limit >= concurrency, "concurrency check failed!");
104 xbt_assert(cnst->concurrency_current == concurrency, "concurrency_current is out-of-date!");
107 // Check that for each variable, all corresponding elements are in the same state (i.e. same element sets)
109 xbt_swag_foreach(varIt, &(sys->variable_set))
111 lmm_variable_t var = (lmm_variable_t)varIt;
113 if (var->cnsts.empty())
116 lmm_element_t elem = &var->cnsts[0];
117 int belong_to_enabled = xbt_swag_belongs(elem, &(elem->constraint->enabled_element_set));
118 int belong_to_disabled = xbt_swag_belongs(elem, &(elem->constraint->disabled_element_set));
119 int belong_to_active = xbt_swag_belongs(elem, &(elem->constraint->active_element_set));
121 for (s_lmm_element_t const& elem : var->cnsts) {
122 xbt_assert(belong_to_enabled == xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)),
123 "Variable inconsistency (1): enabled_element_set");
124 xbt_assert(belong_to_disabled == xbt_swag_belongs(&elem, &(elem.constraint->disabled_element_set)),
125 "Variable inconsistency (2): disabled_element_set");
126 xbt_assert(belong_to_active == xbt_swag_belongs(&elem, &(elem.constraint->active_element_set)),
127 "Variable inconsistency (3): active_element_set");
132 static inline void lmm_variable_remove(lmm_system_t sys, lmm_variable_t var)
134 XBT_IN("(sys=%p, var=%p)", sys, var);
137 // TODOLATER Can do better than that by leaving only the variable in only one enabled_element_set, call
138 // lmm_update_modified_set, and then remove it..
139 if (not var->cnsts.empty())
140 lmm_update_modified_set(sys, var->cnsts[0].constraint);
142 for (s_lmm_element_t& elem : var->cnsts) {
143 if (var->sharing_weight > 0)
144 lmm_decrease_concurrency(&elem);
145 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
146 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
147 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
148 int nelements = xbt_swag_size(&(elem.constraint->enabled_element_set)) +
149 xbt_swag_size(&(elem.constraint->disabled_element_set));
151 make_constraint_inactive(sys, elem.constraint);
153 lmm_on_disabled_var(sys, elem.constraint);
156 // Check if we can enable new variables going through the constraints where var was.
157 // Do it after removing all elements, so the first disabled variables get priority over those with smaller requirement
158 for (s_lmm_element_t& elem : var->cnsts) {
159 if (xbt_swag_size(&(elem.constraint->disabled_element_set)))
160 lmm_on_disabled_var(sys, elem.constraint);
165 lmm_check_concurrency(sys);
170 static void lmm_var_free(lmm_system_t sys, lmm_variable_t var)
172 lmm_variable_remove(sys, var);
173 xbt_mallocator_release(sys->variable_mallocator, var);
176 lmm_system_t lmm_system_new(bool selective_update)
178 s_lmm_variable_t var;
179 s_lmm_constraint_t cnst;
181 lmm_system_t l = new s_lmm_system_t();
184 l->selective_update_active = selective_update;
185 l->visited_counter = 1;
187 XBT_DEBUG("Setting selective_update_active flag to %d", l->selective_update_active);
189 xbt_swag_init(&(l->variable_set), xbt_swag_offset(var, variable_set_hookup));
190 xbt_swag_init(&(l->constraint_set), xbt_swag_offset(cnst, constraint_set_hookup));
192 xbt_swag_init(&(l->active_constraint_set), xbt_swag_offset(cnst, active_constraint_set_hookup));
194 xbt_swag_init(&(l->modified_constraint_set), xbt_swag_offset(cnst, modified_constraint_set_hookup));
195 xbt_swag_init(&(l->saturated_variable_set), xbt_swag_offset(var, saturated_variable_set_hookup));
196 xbt_swag_init(&(l->saturated_constraint_set), xbt_swag_offset(cnst, saturated_constraint_set_hookup));
198 l->variable_mallocator = xbt_mallocator_new(65536,
199 lmm_variable_mallocator_new_f,
200 lmm_variable_mallocator_free_f,
201 lmm_variable_mallocator_reset_f);
203 l->solve_fun = &lmm_solve;
208 void lmm_system_free(lmm_system_t sys)
210 lmm_variable_t var = nullptr;
211 lmm_constraint_t cnst = nullptr;
216 while ((var = (lmm_variable_t) extract_variable(sys))) {
218 char* demangled = abi::__cxa_demangle(typeid(*var->id).name(), 0, 0, &status);
220 XBT_WARN("Probable bug: a %s variable (#%d) not removed before the LMM system destruction.", demangled,
223 lmm_var_free(sys, var);
225 while ((cnst = (lmm_constraint_t) extract_constraint(sys)))
226 lmm_cnst_free(sys, cnst);
228 xbt_mallocator_free(sys->variable_mallocator);
232 static inline void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst)
234 make_constraint_inactive(sys, cnst);
238 lmm_constraint_t lmm_constraint_new(lmm_system_t sys, void *id, double bound_value)
240 lmm_constraint_t cnst = nullptr;
241 s_lmm_element_t elem;
243 cnst = new s_lmm_constraint_t();
245 cnst->id_int = Global_const_debug_id++;
246 xbt_swag_init(&(cnst->enabled_element_set), xbt_swag_offset(elem, enabled_element_set_hookup));
247 xbt_swag_init(&(cnst->disabled_element_set), xbt_swag_offset(elem, disabled_element_set_hookup));
248 xbt_swag_init(&(cnst->active_element_set), xbt_swag_offset(elem, active_element_set_hookup));
250 cnst->bound = bound_value;
251 cnst->concurrency_maximum=0;
252 cnst->concurrency_current=0;
253 cnst->concurrency_limit = sg_concurrency_limit;
255 cnst->sharing_policy = 1; /* FIXME: don't hardcode the value */
256 insert_constraint(sys, cnst);
261 int lmm_constraint_concurrency_limit_get(lmm_constraint_t cnst)
263 return cnst->concurrency_limit;
266 void lmm_constraint_concurrency_limit_set(lmm_constraint_t cnst, int concurrency_limit)
268 xbt_assert(concurrency_limit<0 || cnst->concurrency_maximum<=concurrency_limit,
269 "New concurrency limit should be larger than observed concurrency maximum. Maybe you want to call"
270 " lmm_constraint_concurrency_maximum_reset() to reset the maximum?");
271 cnst->concurrency_limit = concurrency_limit;
274 void lmm_constraint_concurrency_maximum_reset(lmm_constraint_t cnst)
276 cnst->concurrency_maximum = 0;
279 int lmm_constraint_concurrency_maximum_get(lmm_constraint_t cnst)
281 xbt_assert(cnst->concurrency_limit<0 || cnst->concurrency_maximum<=cnst->concurrency_limit,
282 "Very bad: maximum observed concurrency is higher than limit. This is a bug of SURF, please report it.");
283 return cnst->concurrency_maximum;
286 void lmm_constraint_shared(lmm_constraint_t cnst)
288 cnst->sharing_policy = 0;
291 /** Return true if the constraint is shared, and false if it's FATPIPE */
292 int lmm_constraint_sharing_policy(lmm_constraint_t cnst)
294 return (cnst->sharing_policy);
297 static void *lmm_variable_mallocator_new_f()
299 return new s_lmm_variable_t;
302 static void lmm_variable_mallocator_free_f(void *var)
304 delete static_cast<lmm_variable_t>(var);
307 lmm_variable_t lmm_variable_new(lmm_system_t sys, simgrid::surf::Action* id, double sharing_weight, double bound,
308 int number_of_constraints)
310 XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)", sys, id, sharing_weight, bound, number_of_constraints);
312 lmm_variable_t var = (lmm_variable_t)xbt_mallocator_get(sys->variable_mallocator);
314 var->id_int = Global_debug_id++;
315 var->cnsts.reserve(number_of_constraints);
316 var->sharing_weight = sharing_weight;
317 var->staged_weight = 0.0;
319 var->concurrency_share = 1;
321 var->visited = sys->visited_counter - 1;
324 var->func_f = func_f_def;
325 var->func_fp = func_fp_def;
326 var->func_fpi = func_fpi_def;
328 var->variable_set_hookup.next = nullptr;
329 var->variable_set_hookup.prev = nullptr;
330 var->saturated_variable_set_hookup.next = nullptr;
331 var->saturated_variable_set_hookup.prev = nullptr;
334 xbt_swag_insert_at_head(var, &(sys->variable_set));
336 xbt_swag_insert_at_tail(var, &(sys->variable_set));
338 XBT_OUT(" returns %p", var);
342 void lmm_variable_free(lmm_system_t sys, lmm_variable_t var)
344 remove_variable(sys, var);
345 lmm_var_free(sys, var);
348 double lmm_variable_getvalue(lmm_variable_t var)
353 void lmm_variable_concurrency_share_set(lmm_variable_t var, short int concurrency_share)
355 var->concurrency_share=concurrency_share;
358 double lmm_variable_getbound(lmm_variable_t var)
363 void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst, lmm_variable_t var, double consumption_weight)
367 //Check if this variable already has an active element in this constraint
368 //If it does, substract it from the required slack
369 int current_share = 0;
370 if(var->concurrency_share>1){
371 for (s_lmm_element_t& elem : var->cnsts) {
372 if (elem.constraint == cnst && xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)))
373 current_share += lmm_element_concurrency(&elem);
377 //Check if we need to disable the variable
378 if (var->sharing_weight > 0 && var->concurrency_share - current_share > lmm_concurrency_slack(cnst)) {
379 double weight = var->sharing_weight;
380 lmm_disable_var(sys,var);
381 for (s_lmm_element_t const& elem : var->cnsts)
382 lmm_on_disabled_var(sys, elem.constraint);
383 consumption_weight = 0;
384 var->staged_weight=weight;
385 xbt_assert(not var->sharing_weight);
388 xbt_assert(var->cnsts.size() < var->cnsts.capacity(), "Too much constraints");
390 var->cnsts.resize(var->cnsts.size() + 1);
391 s_lmm_element_t& elem = var->cnsts.back();
393 elem.consumption_weight = consumption_weight;
394 elem.constraint = cnst;
397 if (var->sharing_weight) {
398 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
399 lmm_increase_concurrency(&elem);
401 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
403 if (not sys->selective_update_active) {
404 make_constraint_active(sys, cnst);
405 } else if (elem.consumption_weight > 0 || var->sharing_weight > 0) {
406 make_constraint_active(sys, cnst);
407 lmm_update_modified_set(sys, cnst);
408 //TODOLATER: Why do we need this second call?
409 if (var->cnsts.size() > 1)
410 lmm_update_modified_set(sys, var->cnsts[0].constraint);
413 lmm_check_concurrency(sys);
416 void lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst, lmm_variable_t var, double value)
420 lmm_check_concurrency(sys);
422 //BEWARE: In case you have multiple elements in one constraint, this will always add value to the first element.
423 auto elem_it = std::find_if(begin(var->cnsts), end(var->cnsts),
424 [&cnst](s_lmm_element_t const& x) { return x.constraint == cnst; });
425 if (elem_it != end(var->cnsts)) {
426 s_lmm_element_t& elem = *elem_it;
427 if (var->sharing_weight)
428 lmm_decrease_concurrency(&elem);
430 if (cnst->sharing_policy)
431 elem.consumption_weight += value;
433 elem.consumption_weight = std::max(elem.consumption_weight, value);
435 //We need to check that increasing value of the element does not cross the concurrency limit
436 if (var->sharing_weight) {
437 if (lmm_concurrency_slack(cnst) < lmm_element_concurrency(&elem)) {
438 double weight = var->sharing_weight;
439 lmm_disable_var(sys,var);
440 for (s_lmm_element_t const& elem2 : var->cnsts)
441 lmm_on_disabled_var(sys, elem2.constraint);
442 var->staged_weight=weight;
443 xbt_assert(not var->sharing_weight);
445 lmm_increase_concurrency(&elem);
447 lmm_update_modified_set(sys, cnst);
449 lmm_expand(sys, cnst, var, value);
451 lmm_check_concurrency(sys);
454 lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
456 if (num < var->cnsts.size())
457 return (var->cnsts[num].constraint);
462 double lmm_get_cnst_weight_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
464 if (num < var->cnsts.size())
465 return (var->cnsts[num].consumption_weight);
470 int lmm_get_number_of_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var)
472 return (var->cnsts.size());
475 lmm_variable_t lmm_get_var_from_cnst(lmm_system_t /*sys*/, lmm_constraint_t cnst, lmm_element_t * elem)
477 if (*elem == nullptr) {
478 // That is the first call, pick the first element among enabled_element_set (or disabled_element_set if
479 // enabled_element_set is empty)
480 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->enabled_element_set));
481 if (*elem == nullptr)
482 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
484 //elem is not null, so we carry on
485 if(xbt_swag_belongs(*elem,&(cnst->enabled_element_set))){
486 //Look at enabled_element_set, and jump to disabled_element_set when finished
487 *elem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->enabled_element_set.offset);
488 if (*elem == nullptr)
489 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
491 *elem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->disabled_element_set.offset);
495 return (*elem)->variable;
500 //if we modify the swag between calls, normal version may loop forever
501 //this safe version ensures that we browse the swag elements only once
502 lmm_variable_t lmm_get_var_from_cnst_safe(lmm_system_t /*sys*/, lmm_constraint_t cnst, lmm_element_t * elem,
503 lmm_element_t * nextelem, int * numelem)
505 if (*elem == nullptr) {
506 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->enabled_element_set));
507 *numelem = xbt_swag_size(&(cnst->enabled_element_set))+xbt_swag_size(&(cnst->disabled_element_set))-1;
508 if (*elem == nullptr)
509 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
518 //elem is not null, so we carry on
519 if(xbt_swag_belongs(*elem,&(cnst->enabled_element_set))){
520 //Look at enabled_element_set, and jump to disabled_element_set when finished
521 *nextelem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->enabled_element_set.offset);
522 if (*nextelem == nullptr)
523 *nextelem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
525 *nextelem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->disabled_element_set.offset);
527 return (*elem)->variable;
532 void *lmm_constraint_id(lmm_constraint_t cnst)
537 void *lmm_variable_id(lmm_variable_t var)
542 static inline void saturated_constraint_set_update(double usage, int cnst_light_num,
543 dyn_light_t& saturated_constraint_set, double* min_usage)
545 xbt_assert(usage > 0,"Impossible");
547 if (*min_usage < 0 || *min_usage > usage) {
549 XBT_HERE(" min_usage=%f (cnst->remaining / cnst->usage =%f)", *min_usage, usage);
550 saturated_constraint_set.assign(1, cnst_light_num);
551 } else if (*min_usage == usage) {
552 saturated_constraint_set.emplace_back(cnst_light_num);
556 static inline void saturated_variable_set_update(s_lmm_constraint_light_t* cnst_light_tab,
557 const dyn_light_t& saturated_constraint_set, lmm_system_t sys)
559 /* Add active variables (i.e. variables that need to be set) from the set of constraints to saturate (cnst_light_tab)*/
560 for (int const& saturated_cnst : saturated_constraint_set) {
561 lmm_constraint_light_t cnst = &cnst_light_tab[saturated_cnst];
563 xbt_swag_t elem_list = &(cnst->cnst->active_element_set);
564 xbt_swag_foreach(_elem, elem_list) {
565 lmm_element_t elem = (lmm_element_t)_elem;
566 //Visiting active_element_set, so, by construction, should never get a zero weight, correct?
567 xbt_assert(elem->variable->sharing_weight > 0);
568 if (elem->consumption_weight > 0)
569 xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
574 void lmm_print(lmm_system_t sys)
576 std::string buf = std::string("MAX-MIN ( ");
579 /* Printing Objective */
580 xbt_swag_t var_list = &(sys->variable_set);
581 xbt_swag_foreach(_var, var_list) {
582 lmm_variable_t var = (lmm_variable_t)_var;
583 buf = buf + "'" + std::to_string(var->id_int) + "'(" + std::to_string(var->sharing_weight) + ") ";
586 XBT_DEBUG("%20s", buf.c_str());
589 XBT_DEBUG("Constraints");
590 /* Printing Constraints */
592 xbt_swag_t cnst_list = &(sys->active_constraint_set);
593 xbt_swag_foreach(_cnst, cnst_list) {
594 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
596 //Show the enabled variables
598 xbt_swag_t elem_list = &(cnst->enabled_element_set);
600 buf += ((cnst->sharing_policy) ? "(" : "max(");
601 xbt_swag_foreach(_elem, elem_list) {
602 lmm_element_t elem = (lmm_element_t)_elem;
603 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
604 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
605 if(cnst->sharing_policy)
606 sum += elem->consumption_weight * elem->variable->value;
608 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
610 //TODO: Adding disabled elements only for test compatibility, but do we really want them to be printed?
611 elem_list = &(cnst->disabled_element_set);
612 xbt_swag_foreach(_elem, elem_list) {
613 lmm_element_t elem = (lmm_element_t)_elem;
614 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
615 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
616 if(cnst->sharing_policy)
617 sum += elem->consumption_weight * elem->variable->value;
619 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
622 buf = buf + "0) <= " + std::to_string(cnst->bound) + " ('" + std::to_string(cnst->id_int) + "')";
624 if (not cnst->sharing_policy) {
625 buf += " [MAX-Constraint]";
627 XBT_DEBUG("%s", buf.c_str());
629 xbt_assert(not double_positive(sum - cnst->bound, cnst->bound * sg_maxmin_precision),
630 "Incorrect value (%f is not smaller than %f): %g", sum, cnst->bound, sum - cnst->bound);
633 XBT_DEBUG("Variables");
634 /* Printing Result */
635 xbt_swag_foreach(_var, var_list) {
636 lmm_variable_t var = (lmm_variable_t)_var;
637 if (var->bound > 0) {
638 XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->sharing_weight, var->value, var->bound);
639 xbt_assert(not double_positive(var->value - var->bound, var->bound * sg_maxmin_precision),
640 "Incorrect value (%f is not smaller than %f", var->value, var->bound);
642 XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->sharing_weight, var->value);
647 void lmm_solve(lmm_system_t sys)
652 double min_usage = -1;
653 double min_bound = -1;
655 if (not sys->modified)
658 XBT_IN("(sys=%p)", sys);
660 /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only constraints
661 * that changed are considered. Otherwise all constraints with active actions are considered.
663 xbt_swag_t cnst_list = sys->selective_update_active ? &(sys->modified_constraint_set) : &(sys->active_constraint_set);
665 XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
666 /* Init: Only modified code portions: reset the value of active variables */
667 xbt_swag_foreach(_cnst, cnst_list) {
668 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
669 xbt_swag_t elem_list = &(cnst->enabled_element_set);
670 xbt_swag_foreach(_elem, elem_list) {
671 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
672 xbt_assert(var->sharing_weight > 0.0);
677 s_lmm_constraint_light_t* cnst_light_tab = new s_lmm_constraint_light_t[xbt_swag_size(cnst_list)]();
678 int cnst_light_num = 0;
679 dyn_light_t saturated_constraint_set;
681 xbt_swag_foreach_safe(_cnst, _cnst_next, cnst_list) {
682 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
683 /* INIT: Collect constraints that actually need to be saturated (i.e remaining and usage are strictly positive)
684 * into cnst_light_tab. */
685 cnst->remaining = cnst->bound;
686 if (not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision))
689 xbt_swag_t elem_list = &(cnst->enabled_element_set);
690 xbt_swag_foreach(_elem, elem_list) {
691 lmm_element_t elem = (lmm_element_t)_elem;
692 xbt_assert(elem->variable->sharing_weight > 0);
693 if (elem->consumption_weight > 0) {
694 if (cnst->sharing_policy)
695 cnst->usage += elem->consumption_weight / elem->variable->sharing_weight;
696 else if (cnst->usage < elem->consumption_weight / elem->variable->sharing_weight)
697 cnst->usage = elem->consumption_weight / elem->variable->sharing_weight;
699 make_elem_active(elem);
700 simgrid::surf::Action *action = static_cast<simgrid::surf::Action*>(elem->variable->id);
701 if (sys->keep_track && not action->is_linked())
702 sys->keep_track->push_back(*action);
705 XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst->id_int, cnst->usage,
706 cnst->remaining,cnst->concurrency_current,cnst->concurrency_maximum,cnst->concurrency_limit);
707 /* Saturated constraints update */
709 if(cnst->usage > 0) {
710 cnst_light_tab[cnst_light_num].cnst = cnst;
711 cnst->cnst_light = &(cnst_light_tab[cnst_light_num]);
712 cnst_light_tab[cnst_light_num].remaining_over_usage = cnst->remaining / cnst->usage;
713 saturated_constraint_set_update(cnst_light_tab[cnst_light_num].remaining_over_usage,
714 cnst_light_num, saturated_constraint_set, &min_usage);
715 xbt_assert(cnst->active_element_set.count>0, "There is no sense adding a constraint that has no active element!");
720 saturated_variable_set_update( cnst_light_tab, saturated_constraint_set, sys);
722 /* Saturated variables update */
724 /* Fix the variables that have to be */
725 xbt_swag_t var_list = &(sys->saturated_variable_set);
727 lmm_variable_t var = nullptr;
728 xbt_swag_foreach(_var, var_list) {
729 var = (lmm_variable_t)_var;
730 if (var->sharing_weight <= 0.0)
732 /* First check if some of these variables could reach their upper bound and update min_bound accordingly. */
733 XBT_DEBUG("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f", var->id_int,
734 var->bound, var->sharing_weight, min_usage, var->bound * var->sharing_weight);
735 if ((var->bound > 0) && (var->bound * var->sharing_weight < min_usage)) {
737 min_bound = var->bound * var->sharing_weight;
739 min_bound = std::min(min_bound, (var->bound * var->sharing_weight));
740 XBT_DEBUG("Updated min_bound=%f", min_bound);
744 while ((var = (lmm_variable_t)xbt_swag_getFirst(var_list))) {
746 //If no variable could reach its bound, deal iteratively the constraints usage ( at worst one constraint is
747 // saturated at each cycle)
748 var->value = min_usage / var->sharing_weight;
749 XBT_DEBUG("Setting var (%d) value to %f\n", var->id_int, var->value);
751 //If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
752 if (double_equals(min_bound, var->bound * var->sharing_weight, sg_maxmin_precision)) {
753 var->value = var->bound;
754 XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
756 // Variables which bound is different are not considered for this cycle, but they will be afterwards.
757 XBT_DEBUG("Do not consider %p (%d) \n", var, var->id_int);
758 xbt_swag_remove(var, var_list);
762 XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ", min_usage, var->id_int, var->sharing_weight,
763 var->id_int, var->value);
765 /* Update the usage of contraints where this variable is involved */
766 for (s_lmm_element_t& elem : var->cnsts) {
767 lmm_constraint_t cnst = elem.constraint;
768 if (cnst->sharing_policy) {
769 // Remember: shared constraints require that sum(elem.value * var->value) < cnst->bound
770 double_update(&(cnst->remaining), elem.consumption_weight * var->value, cnst->bound * sg_maxmin_precision);
771 double_update(&(cnst->usage), elem.consumption_weight / var->sharing_weight, sg_maxmin_precision);
772 // If the constraint is saturated, remove it from the set of active constraints (light_tab)
773 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
774 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
775 if (cnst->cnst_light) {
776 int index = (cnst->cnst_light-cnst_light_tab);
777 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f ",
778 index,cnst_light_num, cnst->usage, cnst->remaining, cnst->bound);
779 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
780 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
782 cnst->cnst_light = nullptr;
785 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
787 make_elem_inactive(&elem);
789 // Remember: non-shared constraints only require that max(elem.value * var->value) < cnst->bound
791 make_elem_inactive(&elem);
792 xbt_swag_t elem_list = &(cnst->enabled_element_set);
793 xbt_swag_foreach(_elem, elem_list) {
794 lmm_element_t elem2 = static_cast<lmm_element_t>(_elem);
795 xbt_assert(elem2->variable->sharing_weight > 0);
796 if (elem2->variable->value > 0)
798 if (elem2->consumption_weight > 0)
799 cnst->usage = std::max(cnst->usage, elem2->consumption_weight / elem2->variable->sharing_weight);
801 //If the constraint is saturated, remove it from the set of active constraints (light_tab)
802 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
803 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
804 if(cnst->cnst_light) {
805 int index = (cnst->cnst_light-cnst_light_tab);
806 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
807 "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f ", index,cnst_light_num, cnst,
808 cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining, cnst->bound);
809 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
810 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
812 cnst->cnst_light = nullptr;
815 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
816 xbt_assert(cnst->active_element_set.count>0, "Should not keep a maximum constraint that has no active"
817 " element! You want to check the maxmin precision and possible rounding effects." );
821 xbt_swag_remove(var, var_list);
824 /* Find out which variables reach the maximum */
827 saturated_constraint_set.clear();
829 for(pos=0; pos<cnst_light_num; pos++){
830 xbt_assert(cnst_light_tab[pos].cnst->active_element_set.count>0, "Cannot saturate more a constraint that has"
831 " no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>)"
832 " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
833 "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
834 cnst_light_tab[pos].cnst->usage, sg_maxmin_precision, cnst_light_tab[pos-1].cnst->usage);
835 saturated_constraint_set_update(cnst_light_tab[pos].remaining_over_usage, pos, saturated_constraint_set,
839 saturated_variable_set_update(cnst_light_tab, saturated_constraint_set, sys);
841 } while (cnst_light_num > 0);
844 if (sys->selective_update_active)
845 lmm_remove_all_modified_set(sys);
847 if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
851 lmm_check_concurrency(sys);
853 delete[] cnst_light_tab;
857 /** \brief Attribute the value bound to var->bound.
859 * \param sys the lmm_system_t
860 * \param var the lmm_variable_t
861 * \param bound the new bound to associate with var
863 * Makes var->bound equal to bound. Whenever this function is called a change is signed in the system. To
864 * avoid false system changing detection it is a good idea to test (bound != 0) before calling it.
866 void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var, double bound)
871 if (not var->cnsts.empty())
872 lmm_update_modified_set(sys, var->cnsts[0].constraint);
875 int lmm_concurrency_slack(lmm_constraint_t cnstr){
876 //FIXME MARTIN: Replace by infinite value std::numeric_limits<int>::(max)(), or something better within Simgrid?
877 if(cnstr->concurrency_limit<0)
880 return cnstr->concurrency_limit - cnstr->concurrency_current;
883 /** \brief Measure the minimum concurrency slack across all constraints where the given var is involved */
884 int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var){
885 int minslack = std::numeric_limits<int>::max();
886 for (s_lmm_element_t const& elem : var->cnsts) {
887 int slack = lmm_concurrency_slack(elem.constraint);
889 //This is only an optimization, to avoid looking at more constraints when slack is already zero
890 //Disable it when debugging to let lmm_concurrency_slack catch nasty things
891 if (not slack && not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug))
901 /* /Check if a variable can be enabled
903 * Make sure to set staged_weight before, if your intent is only to check concurrency
905 int lmm_can_enable_var(lmm_variable_t var){
906 return var->staged_weight>0 && lmm_cnstrs_min_concurrency_slack(var)>=var->concurrency_share;
909 //Small remark: In this implementation of lmm_enable_var and lmm_disable_var, we will meet multiple times with var when
910 // running lmm_update_modified_set.
911 //A priori not a big performance issue, but we might do better by calling lmm_update_modified_set within the for loops
912 // (after doing the first for enabling==1, and before doing the last for disabling==1)
913 void lmm_enable_var(lmm_system_t sys, lmm_variable_t var){
914 xbt_assert(lmm_can_enable_var(var));
916 var->sharing_weight = var->staged_weight;
917 var->staged_weight = 0;
919 // Enabling the variable, move to var to list head. Subtlety is: here, we need to call lmm_update_modified_set AFTER
920 // moving at least one element of var.
922 xbt_swag_remove(var, &(sys->variable_set));
923 xbt_swag_insert_at_head(var, &(sys->variable_set));
924 for (s_lmm_element_t& elem : var->cnsts) {
925 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
926 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
927 lmm_increase_concurrency(&elem);
929 if (not var->cnsts.empty())
930 lmm_update_modified_set(sys, var->cnsts[0].constraint);
932 //When used within lmm_on_disabled_var, we would get an assertion fail, because transiently there can be variables
933 // that are staged and could be activated.
934 //Anyway, caller functions all call lmm_check_concurrency() in the end.
937 void lmm_disable_var(lmm_system_t sys, lmm_variable_t var){
938 xbt_assert(not var->staged_weight, "Staged weight should have been cleared");
939 // Disabling the variable, move to var to list tail. Subtlety is: here, we need to call lmm_update_modified_set BEFORE
940 // moving the last element of var.
941 xbt_swag_remove(var, &(sys->variable_set));
942 xbt_swag_insert_at_tail(var, &(sys->variable_set));
943 if (not var->cnsts.empty())
944 lmm_update_modified_set(sys, var->cnsts[0].constraint);
945 for (s_lmm_element_t& elem : var->cnsts) {
946 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
947 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
949 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
951 lmm_decrease_concurrency(&elem);
954 var->sharing_weight = 0.0;
955 var->staged_weight=0.0;
957 lmm_check_concurrency(sys);
960 /* /brief Find variables that can be enabled and enable them.
962 * Assuming that the variable has already been removed from non-zero weights
963 * Can we find a staged variable to add?
964 * If yes, check that none of the constraints that this variable is involved in is at the limit of its concurrency
965 * And then add it to enabled variables
967 void lmm_on_disabled_var(lmm_system_t sys, lmm_constraint_t cnstr){
969 if(cnstr->concurrency_limit<0)
972 int numelem = xbt_swag_size(&(cnstr->disabled_element_set));
976 lmm_element_t elem = (lmm_element_t)xbt_swag_getFirst(&(cnstr->disabled_element_set));
978 //Cannot use xbt_swag_foreach, because lmm_enable_var will modify disabled_element_set.. within the loop
979 while (numelem-- && elem) {
981 lmm_element_t nextelem = (lmm_element_t)xbt_swag_getNext(elem, cnstr->disabled_element_set.offset);
983 if (elem->variable->staged_weight>0 ){
984 //Found a staged variable
985 //TODOLATER: Add random timing function to model reservation protocol fuzziness? Then how to make sure that
986 //staged variables will eventually be called?
987 if(lmm_can_enable_var(elem->variable)){
988 lmm_enable_var(sys,elem->variable);
992 xbt_assert(cnstr->concurrency_current<=cnstr->concurrency_limit,"Concurrency overflow!");
993 if(cnstr->concurrency_current==cnstr->concurrency_limit)
999 //We could get an assertion fail, because transiently there can be variables that are staged and could be activated.
1000 //And we need to go through all constraints of the disabled var before getting back a coherent state.
1001 //Anyway, caller functions all call lmm_check_concurrency() in the end.
1004 /* \brief update the weight of a variable, and enable/disable it.
1005 * @return Returns whether a change was made
1007 void lmm_update_variable_weight(lmm_system_t sys, lmm_variable_t var, double weight)
1009 xbt_assert(weight>=0,"Variable weight should not be negative!");
1011 if (weight == var->sharing_weight)
1014 int enabling_var = (weight > 0 && var->sharing_weight <= 0);
1015 int disabling_var = (weight <= 0 && var->sharing_weight > 0);
1017 XBT_IN("(sys=%p, var=%p, weight=%f)", sys, var, weight);
1021 //Are we enabling this variable?
1023 var->staged_weight = weight;
1024 int minslack = lmm_cnstrs_min_concurrency_slack(var);
1025 if (minslack < var->concurrency_share) {
1026 XBT_DEBUG("Staging var (instead of enabling) because min concurrency slack %i, with weight %f and concurrency"
1027 " share %i", minslack, weight, var->concurrency_share);
1030 XBT_DEBUG("Enabling var with min concurrency slack %i", minslack);
1031 lmm_enable_var(sys,var);
1032 } else if (disabling_var){
1033 //Are we disabling this variable?
1034 lmm_disable_var(sys,var);
1036 var->sharing_weight = weight;
1039 lmm_check_concurrency(sys);
1044 double lmm_get_variable_weight(lmm_variable_t var)
1046 return var->sharing_weight;
1049 void lmm_update_constraint_bound(lmm_system_t sys, lmm_constraint_t cnst, double bound)
1052 lmm_update_modified_set(sys, cnst);
1053 cnst->bound = bound;
1056 int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
1058 return xbt_swag_belongs(cnst, &(sys->active_constraint_set));
1061 inline lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t sys)
1063 return (lmm_constraint_t)xbt_swag_getFirst(&(sys->active_constraint_set));
1066 inline lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t sys, lmm_constraint_t cnst)
1068 return (lmm_constraint_t)xbt_swag_getNext(cnst, (sys->active_constraint_set).offset);
1071 /** \brief Update the constraint set propagating recursively to other constraints so the system should not be entirely
1074 * \param sys the lmm_system_t
1075 * \param cnst the lmm_constraint_t affected by the change
1077 * A recursive algorithm to optimize the system recalculation selecting only constraints that have changed. Each
1078 * constraint change is propagated to the list of constraints for each variable.
1080 static void lmm_update_modified_set_rec(lmm_system_t sys, lmm_constraint_t cnst)
1084 //TODOLATER: Why lmm_modified_set has been changed in git version 2392B5157...? Looks equivalent logically and less obvious..
1085 xbt_swag_foreach(_elem, &cnst->enabled_element_set) {
1086 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
1087 for (s_lmm_element_t const& elem : var->cnsts) {
1088 if (var->visited == sys->visited_counter)
1090 if (elem.constraint != cnst && not xbt_swag_belongs(elem.constraint, &sys->modified_constraint_set)) {
1091 xbt_swag_insert(elem.constraint, &sys->modified_constraint_set);
1092 lmm_update_modified_set_rec(sys, elem.constraint);
1095 //var will be ignored in later visits as long as sys->visited_counter does not move
1096 var->visited = sys->visited_counter;
1100 static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst)
1102 /* nothing to do if selective update isn't active */
1103 if (sys->selective_update_active && not xbt_swag_belongs(cnst, &sys->modified_constraint_set)) {
1104 xbt_swag_insert(cnst, &sys->modified_constraint_set);
1105 lmm_update_modified_set_rec(sys, cnst);
1109 /** \brief Remove all constraints of the modified_constraint_set.
1111 * \param sys the lmm_system_t
1113 static void lmm_remove_all_modified_set(lmm_system_t sys)
1115 // We cleverly un-flag all variables just by incrementing sys->visited_counter
1116 // In effect, the var->visited value will no more be equal to sys->visited counter
1117 // To be clean, when visited counter has wrapped around, we force these var->visited values so that variables that
1118 // were in the modified a long long time ago are not wrongly skipped here, which would lead to very nasty bugs
1119 // (i.e. not readibily reproducible, and requiring a lot of run time before happening).
1120 if (++sys->visited_counter == 1) {
1121 /* the counter wrapped around, reset each variable->visited */
1123 xbt_swag_foreach(_var, &sys->variable_set)
1124 ((lmm_variable_t)_var)->visited = 0;
1126 xbt_swag_reset(&sys->modified_constraint_set);
1130 * Returns resource load (in flop per second, or byte per second, or similar)
1132 * If the resource is shared (the default case), the load is sum of resource usage made by every variables located on
1135 * If the resource is not shared (ie in FATPIPE mode), then the load is the max (not the sum) of all resource usages
1136 * located on this resource.
1138 * \param cnst the lmm_constraint_t associated to the resource
1140 double lmm_constraint_get_usage(lmm_constraint_t cnst) {
1142 xbt_swag_t elem_list = &(cnst->enabled_element_set);
1145 xbt_swag_foreach(_elem, elem_list)
1147 lmm_element_t elem = (lmm_element_t)_elem;
1148 if (elem->consumption_weight > 0) {
1149 if (cnst->sharing_policy)
1150 usage += elem->consumption_weight * elem->variable->value;
1151 else if (usage < elem->consumption_weight * elem->variable->value)
1152 usage = std::max(usage, elem->consumption_weight * elem->variable->value);
1158 int lmm_constraint_get_variable_amount(lmm_constraint_t cnst) {
1160 xbt_swag_t elem_list = &(cnst->enabled_element_set);
1163 xbt_swag_foreach(_elem, elem_list) {
1164 lmm_element_t elem = (lmm_element_t)_elem;
1165 if (elem->consumption_weight > 0)