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);
157 // Check if we can enable new variables going through the constraints where var was.
158 // Do it after removing all elements, so the first disabled variables get priority over those with smaller requirement
159 for (s_lmm_element_t& elem : var->cnsts) {
160 if (xbt_swag_size(&(elem.constraint->disabled_element_set)))
161 lmm_on_disabled_var(sys, elem.constraint);
166 lmm_check_concurrency(sys);
168 xbt_mallocator_release(sys->variable_mallocator, var);
172 lmm_system_t lmm_system_new(bool selective_update)
174 s_lmm_variable_t var;
175 s_lmm_constraint_t cnst;
177 lmm_system_t l = new s_lmm_system_t();
180 l->selective_update_active = selective_update;
181 l->visited_counter = 1;
183 XBT_DEBUG("Setting selective_update_active flag to %d", l->selective_update_active);
185 xbt_swag_init(&(l->variable_set), xbt_swag_offset(var, variable_set_hookup));
186 xbt_swag_init(&(l->constraint_set), xbt_swag_offset(cnst, constraint_set_hookup));
188 xbt_swag_init(&(l->active_constraint_set), xbt_swag_offset(cnst, active_constraint_set_hookup));
190 xbt_swag_init(&(l->modified_constraint_set), xbt_swag_offset(cnst, modified_constraint_set_hookup));
191 xbt_swag_init(&(l->saturated_variable_set), xbt_swag_offset(var, saturated_variable_set_hookup));
192 xbt_swag_init(&(l->saturated_constraint_set), xbt_swag_offset(cnst, saturated_constraint_set_hookup));
194 l->variable_mallocator = xbt_mallocator_new(65536,
195 lmm_variable_mallocator_new_f,
196 lmm_variable_mallocator_free_f,
197 lmm_variable_mallocator_reset_f);
199 l->solve_fun = &lmm_solve;
204 void lmm_system_free(lmm_system_t sys)
206 lmm_variable_t var = nullptr;
207 lmm_constraint_t cnst = nullptr;
212 while ((var = (lmm_variable_t) extract_variable(sys))) {
213 auto demangled = simgrid::xbt::demangle(typeid(*var->id).name());
214 XBT_WARN("Probable bug: a %s variable (#%d) not removed before the LMM system destruction.", demangled.get(),
216 lmm_var_free(sys, var);
218 while ((cnst = (lmm_constraint_t) extract_constraint(sys)))
219 lmm_cnst_free(sys, cnst);
221 xbt_mallocator_free(sys->variable_mallocator);
225 static inline void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst)
227 make_constraint_inactive(sys, cnst);
231 lmm_constraint_t lmm_constraint_new(lmm_system_t sys, void *id, double bound_value)
233 lmm_constraint_t cnst = nullptr;
234 s_lmm_element_t elem;
236 cnst = new s_lmm_constraint_t();
238 cnst->id_int = Global_const_debug_id++;
239 xbt_swag_init(&(cnst->enabled_element_set), xbt_swag_offset(elem, enabled_element_set_hookup));
240 xbt_swag_init(&(cnst->disabled_element_set), xbt_swag_offset(elem, disabled_element_set_hookup));
241 xbt_swag_init(&(cnst->active_element_set), xbt_swag_offset(elem, active_element_set_hookup));
243 cnst->bound = bound_value;
244 cnst->concurrency_maximum=0;
245 cnst->concurrency_current=0;
246 cnst->concurrency_limit = sg_concurrency_limit;
248 cnst->sharing_policy = 1; /* FIXME: don't hardcode the value */
249 insert_constraint(sys, cnst);
254 int lmm_constraint_concurrency_limit_get(lmm_constraint_t cnst)
256 return cnst->concurrency_limit;
259 void lmm_constraint_concurrency_limit_set(lmm_constraint_t cnst, int concurrency_limit)
261 xbt_assert(concurrency_limit<0 || cnst->concurrency_maximum<=concurrency_limit,
262 "New concurrency limit should be larger than observed concurrency maximum. Maybe you want to call"
263 " lmm_constraint_concurrency_maximum_reset() to reset the maximum?");
264 cnst->concurrency_limit = concurrency_limit;
267 void lmm_constraint_concurrency_maximum_reset(lmm_constraint_t cnst)
269 cnst->concurrency_maximum = 0;
272 int lmm_constraint_concurrency_maximum_get(lmm_constraint_t cnst)
274 xbt_assert(cnst->concurrency_limit<0 || cnst->concurrency_maximum<=cnst->concurrency_limit,
275 "Very bad: maximum observed concurrency is higher than limit. This is a bug of SURF, please report it.");
276 return cnst->concurrency_maximum;
279 void lmm_constraint_shared(lmm_constraint_t cnst)
281 cnst->sharing_policy = 0;
284 /** Return true if the constraint is shared, and false if it's FATPIPE */
285 int lmm_constraint_sharing_policy(lmm_constraint_t cnst)
287 return (cnst->sharing_policy);
290 static void *lmm_variable_mallocator_new_f()
292 return new s_lmm_variable_t;
295 static void lmm_variable_mallocator_free_f(void *var)
297 delete static_cast<lmm_variable_t>(var);
300 lmm_variable_t lmm_variable_new(lmm_system_t sys, simgrid::surf::Action* id, double sharing_weight, double bound,
301 int number_of_constraints)
303 XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)", sys, id, sharing_weight, bound, number_of_constraints);
305 lmm_variable_t var = (lmm_variable_t)xbt_mallocator_get(sys->variable_mallocator);
307 var->id_int = Global_debug_id++;
308 var->cnsts.reserve(number_of_constraints);
309 var->sharing_weight = sharing_weight;
310 var->staged_weight = 0.0;
312 var->concurrency_share = 1;
314 var->visited = sys->visited_counter - 1;
317 var->func_f = func_f_def;
318 var->func_fp = func_fp_def;
319 var->func_fpi = func_fpi_def;
321 var->variable_set_hookup.next = nullptr;
322 var->variable_set_hookup.prev = nullptr;
323 var->saturated_variable_set_hookup.next = nullptr;
324 var->saturated_variable_set_hookup.prev = nullptr;
327 xbt_swag_insert_at_head(var, &(sys->variable_set));
329 xbt_swag_insert_at_tail(var, &(sys->variable_set));
331 XBT_OUT(" returns %p", var);
335 void lmm_variable_free(lmm_system_t sys, lmm_variable_t var)
337 remove_variable(sys, var);
338 lmm_var_free(sys, var);
341 double lmm_variable_getvalue(lmm_variable_t var)
346 void lmm_variable_concurrency_share_set(lmm_variable_t var, short int concurrency_share)
348 var->concurrency_share=concurrency_share;
351 double lmm_variable_getbound(lmm_variable_t var)
356 void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst, lmm_variable_t var, double consumption_weight)
360 //Check if this variable already has an active element in this constraint
361 //If it does, substract it from the required slack
362 int current_share = 0;
363 if(var->concurrency_share>1){
364 for (s_lmm_element_t& elem : var->cnsts) {
365 if (elem.constraint == cnst && xbt_swag_belongs(&elem, &(elem.constraint->enabled_element_set)))
366 current_share += lmm_element_concurrency(&elem);
370 //Check if we need to disable the variable
371 if (var->sharing_weight > 0 && var->concurrency_share - current_share > lmm_concurrency_slack(cnst)) {
372 double weight = var->sharing_weight;
373 lmm_disable_var(sys,var);
374 for (s_lmm_element_t const& elem : var->cnsts)
375 lmm_on_disabled_var(sys, elem.constraint);
376 consumption_weight = 0;
377 var->staged_weight=weight;
378 xbt_assert(not var->sharing_weight);
381 xbt_assert(var->cnsts.size() < var->cnsts.capacity(), "Too much constraints");
383 var->cnsts.resize(var->cnsts.size() + 1);
384 s_lmm_element_t& elem = var->cnsts.back();
386 elem.consumption_weight = consumption_weight;
387 elem.constraint = cnst;
390 if (var->sharing_weight) {
391 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
392 lmm_increase_concurrency(&elem);
394 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
396 if (not sys->selective_update_active) {
397 make_constraint_active(sys, cnst);
398 } else if (elem.consumption_weight > 0 || var->sharing_weight > 0) {
399 make_constraint_active(sys, cnst);
400 lmm_update_modified_set(sys, cnst);
401 //TODOLATER: Why do we need this second call?
402 if (var->cnsts.size() > 1)
403 lmm_update_modified_set(sys, var->cnsts[0].constraint);
406 lmm_check_concurrency(sys);
409 void lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst, lmm_variable_t var, double value)
413 lmm_check_concurrency(sys);
415 //BEWARE: In case you have multiple elements in one constraint, this will always add value to the first element.
416 auto elem_it = std::find_if(begin(var->cnsts), end(var->cnsts),
417 [&cnst](s_lmm_element_t const& x) { return x.constraint == cnst; });
418 if (elem_it != end(var->cnsts)) {
419 s_lmm_element_t& elem = *elem_it;
420 if (var->sharing_weight)
421 lmm_decrease_concurrency(&elem);
423 if (cnst->sharing_policy)
424 elem.consumption_weight += value;
426 elem.consumption_weight = std::max(elem.consumption_weight, value);
428 //We need to check that increasing value of the element does not cross the concurrency limit
429 if (var->sharing_weight) {
430 if (lmm_concurrency_slack(cnst) < lmm_element_concurrency(&elem)) {
431 double weight = var->sharing_weight;
432 lmm_disable_var(sys,var);
433 for (s_lmm_element_t const& elem2 : var->cnsts)
434 lmm_on_disabled_var(sys, elem2.constraint);
435 var->staged_weight=weight;
436 xbt_assert(not var->sharing_weight);
438 lmm_increase_concurrency(&elem);
440 lmm_update_modified_set(sys, cnst);
442 lmm_expand(sys, cnst, var, value);
444 lmm_check_concurrency(sys);
447 lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
449 if (num < var->cnsts.size())
450 return (var->cnsts[num].constraint);
455 double lmm_get_cnst_weight_from_var(lmm_system_t /*sys*/, lmm_variable_t var, unsigned num)
457 if (num < var->cnsts.size())
458 return (var->cnsts[num].consumption_weight);
463 int lmm_get_number_of_cnst_from_var(lmm_system_t /*sys*/, lmm_variable_t var)
465 return (var->cnsts.size());
468 lmm_variable_t lmm_get_var_from_cnst(lmm_system_t /*sys*/, lmm_constraint_t cnst, lmm_element_t * elem)
470 if (*elem == nullptr) {
471 // That is the first call, pick the first element among enabled_element_set (or disabled_element_set if
472 // enabled_element_set is empty)
473 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->enabled_element_set));
474 if (*elem == nullptr)
475 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
477 //elem is not null, so we carry on
478 if(xbt_swag_belongs(*elem,&(cnst->enabled_element_set))){
479 //Look at enabled_element_set, and jump to disabled_element_set when finished
480 *elem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->enabled_element_set.offset);
481 if (*elem == nullptr)
482 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
484 *elem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->disabled_element_set.offset);
488 return (*elem)->variable;
493 //if we modify the swag between calls, normal version may loop forever
494 //this safe version ensures that we browse the swag elements only once
495 lmm_variable_t lmm_get_var_from_cnst_safe(lmm_system_t /*sys*/, lmm_constraint_t cnst, lmm_element_t * elem,
496 lmm_element_t * nextelem, int * numelem)
498 if (*elem == nullptr) {
499 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->enabled_element_set));
500 *numelem = xbt_swag_size(&(cnst->enabled_element_set))+xbt_swag_size(&(cnst->disabled_element_set))-1;
501 if (*elem == nullptr)
502 *elem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
511 //elem is not null, so we carry on
512 if(xbt_swag_belongs(*elem,&(cnst->enabled_element_set))){
513 //Look at enabled_element_set, and jump to disabled_element_set when finished
514 *nextelem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->enabled_element_set.offset);
515 if (*nextelem == nullptr)
516 *nextelem = (lmm_element_t) xbt_swag_getFirst(&(cnst->disabled_element_set));
518 *nextelem = (lmm_element_t) xbt_swag_getNext(*elem, cnst->disabled_element_set.offset);
520 return (*elem)->variable;
525 void *lmm_constraint_id(lmm_constraint_t cnst)
530 void *lmm_variable_id(lmm_variable_t var)
535 static inline void saturated_constraint_set_update(double usage, int cnst_light_num,
536 dyn_light_t& saturated_constraint_set, double* min_usage)
538 xbt_assert(usage > 0,"Impossible");
540 if (*min_usage < 0 || *min_usage > usage) {
542 XBT_HERE(" min_usage=%f (cnst->remaining / cnst->usage =%f)", *min_usage, usage);
543 saturated_constraint_set.assign(1, cnst_light_num);
544 } else if (*min_usage == usage) {
545 saturated_constraint_set.emplace_back(cnst_light_num);
549 static inline void saturated_variable_set_update(s_lmm_constraint_light_t* cnst_light_tab,
550 const dyn_light_t& saturated_constraint_set, lmm_system_t sys)
552 /* Add active variables (i.e. variables that need to be set) from the set of constraints to saturate (cnst_light_tab)*/
553 for (int const& saturated_cnst : saturated_constraint_set) {
554 lmm_constraint_light_t cnst = &cnst_light_tab[saturated_cnst];
556 xbt_swag_t elem_list = &(cnst->cnst->active_element_set);
557 xbt_swag_foreach(_elem, elem_list) {
558 lmm_element_t elem = (lmm_element_t)_elem;
559 //Visiting active_element_set, so, by construction, should never get a zero weight, correct?
560 xbt_assert(elem->variable->sharing_weight > 0);
561 if (elem->consumption_weight > 0)
562 xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
567 void lmm_print(lmm_system_t sys)
569 std::string buf = std::string("MAX-MIN ( ");
572 /* Printing Objective */
573 xbt_swag_t var_list = &(sys->variable_set);
574 xbt_swag_foreach(_var, var_list) {
575 lmm_variable_t var = (lmm_variable_t)_var;
576 buf = buf + "'" + std::to_string(var->id_int) + "'(" + std::to_string(var->sharing_weight) + ") ";
579 XBT_DEBUG("%20s", buf.c_str());
582 XBT_DEBUG("Constraints");
583 /* Printing Constraints */
585 xbt_swag_t cnst_list = &(sys->active_constraint_set);
586 xbt_swag_foreach(_cnst, cnst_list) {
587 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
589 //Show the enabled variables
591 xbt_swag_t elem_list = &(cnst->enabled_element_set);
593 buf += ((cnst->sharing_policy) ? "(" : "max(");
594 xbt_swag_foreach(_elem, elem_list) {
595 lmm_element_t elem = (lmm_element_t)_elem;
596 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
597 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
598 if(cnst->sharing_policy)
599 sum += elem->consumption_weight * elem->variable->value;
601 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
603 //TODO: Adding disabled elements only for test compatibility, but do we really want them to be printed?
604 elem_list = &(cnst->disabled_element_set);
605 xbt_swag_foreach(_elem, elem_list) {
606 lmm_element_t elem = (lmm_element_t)_elem;
607 buf = buf + std::to_string(elem->consumption_weight) + ".'" + std::to_string(elem->variable->id_int) + "'(" +
608 std::to_string(elem->variable->value) + ")" + ((cnst->sharing_policy) ? " + " : " , ");
609 if(cnst->sharing_policy)
610 sum += elem->consumption_weight * elem->variable->value;
612 sum = std::max(sum, elem->consumption_weight * elem->variable->value);
615 buf = buf + "0) <= " + std::to_string(cnst->bound) + " ('" + std::to_string(cnst->id_int) + "')";
617 if (not cnst->sharing_policy) {
618 buf += " [MAX-Constraint]";
620 XBT_DEBUG("%s", buf.c_str());
622 xbt_assert(not double_positive(sum - cnst->bound, cnst->bound * sg_maxmin_precision),
623 "Incorrect value (%f is not smaller than %f): %g", sum, cnst->bound, sum - cnst->bound);
626 XBT_DEBUG("Variables");
627 /* Printing Result */
628 xbt_swag_foreach(_var, var_list) {
629 lmm_variable_t var = (lmm_variable_t)_var;
630 if (var->bound > 0) {
631 XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->sharing_weight, var->value, var->bound);
632 xbt_assert(not double_positive(var->value - var->bound, var->bound * sg_maxmin_precision),
633 "Incorrect value (%f is not smaller than %f", var->value, var->bound);
635 XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->sharing_weight, var->value);
640 void lmm_solve(lmm_system_t sys)
645 double min_usage = -1;
646 double min_bound = -1;
648 if (not sys->modified)
651 XBT_IN("(sys=%p)", sys);
653 /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only constraints
654 * that changed are considered. Otherwise all constraints with active actions are considered.
656 xbt_swag_t cnst_list = sys->selective_update_active ? &(sys->modified_constraint_set) : &(sys->active_constraint_set);
658 XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
659 /* Init: Only modified code portions: reset the value of active variables */
660 xbt_swag_foreach(_cnst, cnst_list) {
661 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
662 xbt_swag_t elem_list = &(cnst->enabled_element_set);
663 xbt_swag_foreach(_elem, elem_list) {
664 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
665 xbt_assert(var->sharing_weight > 0.0);
670 s_lmm_constraint_light_t* cnst_light_tab = new s_lmm_constraint_light_t[xbt_swag_size(cnst_list)]();
671 int cnst_light_num = 0;
672 dyn_light_t saturated_constraint_set;
674 xbt_swag_foreach_safe(_cnst, _cnst_next, cnst_list) {
675 lmm_constraint_t cnst = (lmm_constraint_t)_cnst;
676 /* INIT: Collect constraints that actually need to be saturated (i.e remaining and usage are strictly positive)
677 * into cnst_light_tab. */
678 cnst->remaining = cnst->bound;
679 if (not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision))
682 xbt_swag_t elem_list = &(cnst->enabled_element_set);
683 xbt_swag_foreach(_elem, elem_list) {
684 lmm_element_t elem = (lmm_element_t)_elem;
685 xbt_assert(elem->variable->sharing_weight > 0);
686 if (elem->consumption_weight > 0) {
687 if (cnst->sharing_policy)
688 cnst->usage += elem->consumption_weight / elem->variable->sharing_weight;
689 else if (cnst->usage < elem->consumption_weight / elem->variable->sharing_weight)
690 cnst->usage = elem->consumption_weight / elem->variable->sharing_weight;
692 make_elem_active(elem);
693 simgrid::surf::Action *action = static_cast<simgrid::surf::Action*>(elem->variable->id);
694 if (sys->keep_track && not action->is_linked())
695 sys->keep_track->push_back(*action);
698 XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst->id_int, cnst->usage,
699 cnst->remaining,cnst->concurrency_current,cnst->concurrency_maximum,cnst->concurrency_limit);
700 /* Saturated constraints update */
702 if(cnst->usage > 0) {
703 cnst_light_tab[cnst_light_num].cnst = cnst;
704 cnst->cnst_light = &(cnst_light_tab[cnst_light_num]);
705 cnst_light_tab[cnst_light_num].remaining_over_usage = cnst->remaining / cnst->usage;
706 saturated_constraint_set_update(cnst_light_tab[cnst_light_num].remaining_over_usage,
707 cnst_light_num, saturated_constraint_set, &min_usage);
708 xbt_assert(cnst->active_element_set.count>0, "There is no sense adding a constraint that has no active element!");
713 saturated_variable_set_update( cnst_light_tab, saturated_constraint_set, sys);
715 /* Saturated variables update */
717 /* Fix the variables that have to be */
718 xbt_swag_t var_list = &(sys->saturated_variable_set);
720 lmm_variable_t var = nullptr;
721 xbt_swag_foreach(_var, var_list) {
722 var = (lmm_variable_t)_var;
723 if (var->sharing_weight <= 0.0)
725 /* First check if some of these variables could reach their upper bound and update min_bound accordingly. */
726 XBT_DEBUG("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f", var->id_int,
727 var->bound, var->sharing_weight, min_usage, var->bound * var->sharing_weight);
728 if ((var->bound > 0) && (var->bound * var->sharing_weight < min_usage)) {
730 min_bound = var->bound * var->sharing_weight;
732 min_bound = std::min(min_bound, (var->bound * var->sharing_weight));
733 XBT_DEBUG("Updated min_bound=%f", min_bound);
737 while ((var = (lmm_variable_t)xbt_swag_getFirst(var_list))) {
739 //If no variable could reach its bound, deal iteratively the constraints usage ( at worst one constraint is
740 // saturated at each cycle)
741 var->value = min_usage / var->sharing_weight;
742 XBT_DEBUG("Setting var (%d) value to %f\n", var->id_int, var->value);
744 //If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
745 if (double_equals(min_bound, var->bound * var->sharing_weight, sg_maxmin_precision)) {
746 var->value = var->bound;
747 XBT_DEBUG("Setting %p (%d) value to %f\n", var, var->id_int, var->value);
749 // Variables which bound is different are not considered for this cycle, but they will be afterwards.
750 XBT_DEBUG("Do not consider %p (%d) \n", var, var->id_int);
751 xbt_swag_remove(var, var_list);
755 XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ", min_usage, var->id_int, var->sharing_weight,
756 var->id_int, var->value);
758 /* Update the usage of contraints where this variable is involved */
759 for (s_lmm_element_t& elem : var->cnsts) {
760 lmm_constraint_t cnst = elem.constraint;
761 if (cnst->sharing_policy) {
762 // Remember: shared constraints require that sum(elem.value * var->value) < cnst->bound
763 double_update(&(cnst->remaining), elem.consumption_weight * var->value, cnst->bound * sg_maxmin_precision);
764 double_update(&(cnst->usage), elem.consumption_weight / var->sharing_weight, sg_maxmin_precision);
765 // If the constraint is saturated, remove it from the set of active constraints (light_tab)
766 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
767 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
768 if (cnst->cnst_light) {
769 int index = (cnst->cnst_light-cnst_light_tab);
770 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f ",
771 index,cnst_light_num, cnst->usage, cnst->remaining, cnst->bound);
772 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
773 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
775 cnst->cnst_light = nullptr;
778 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
780 make_elem_inactive(&elem);
782 // Remember: non-shared constraints only require that max(elem.value * var->value) < cnst->bound
784 make_elem_inactive(&elem);
785 xbt_swag_t elem_list = &(cnst->enabled_element_set);
786 xbt_swag_foreach(_elem, elem_list) {
787 lmm_element_t elem2 = static_cast<lmm_element_t>(_elem);
788 xbt_assert(elem2->variable->sharing_weight > 0);
789 if (elem2->variable->value > 0)
791 if (elem2->consumption_weight > 0)
792 cnst->usage = std::max(cnst->usage, elem2->consumption_weight / elem2->variable->sharing_weight);
794 //If the constraint is saturated, remove it from the set of active constraints (light_tab)
795 if (not double_positive(cnst->usage, sg_maxmin_precision) ||
796 not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
797 if(cnst->cnst_light) {
798 int index = (cnst->cnst_light-cnst_light_tab);
799 XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
800 "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f ", index,cnst_light_num, cnst,
801 cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining, cnst->bound);
802 cnst_light_tab[index]=cnst_light_tab[cnst_light_num-1];
803 cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
805 cnst->cnst_light = nullptr;
808 cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
809 xbt_assert(cnst->active_element_set.count>0, "Should not keep a maximum constraint that has no active"
810 " element! You want to check the maxmin precision and possible rounding effects." );
814 xbt_swag_remove(var, var_list);
817 /* Find out which variables reach the maximum */
820 saturated_constraint_set.clear();
822 for(pos=0; pos<cnst_light_num; pos++){
823 xbt_assert(cnst_light_tab[pos].cnst->active_element_set.count>0, "Cannot saturate more a constraint that has"
824 " no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>)"
825 " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
826 "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
827 cnst_light_tab[pos].cnst->usage, sg_maxmin_precision, cnst_light_tab[pos-1].cnst->usage);
828 saturated_constraint_set_update(cnst_light_tab[pos].remaining_over_usage, pos, saturated_constraint_set,
832 saturated_variable_set_update(cnst_light_tab, saturated_constraint_set, sys);
834 } while (cnst_light_num > 0);
837 if (sys->selective_update_active)
838 lmm_remove_all_modified_set(sys);
840 if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
844 lmm_check_concurrency(sys);
846 delete[] cnst_light_tab;
850 /** \brief Attribute the value bound to var->bound.
852 * \param sys the lmm_system_t
853 * \param var the lmm_variable_t
854 * \param bound the new bound to associate with var
856 * Makes var->bound equal to bound. Whenever this function is called a change is signed in the system. To
857 * avoid false system changing detection it is a good idea to test (bound != 0) before calling it.
859 void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var, double bound)
864 if (not var->cnsts.empty())
865 lmm_update_modified_set(sys, var->cnsts[0].constraint);
868 int lmm_concurrency_slack(lmm_constraint_t cnstr)
870 if (cnstr->concurrency_limit < 0)
871 return std::numeric_limits<int>::max();
872 return cnstr->concurrency_limit - cnstr->concurrency_current;
875 /** \brief Measure the minimum concurrency slack across all constraints where the given var is involved */
876 int lmm_cnstrs_min_concurrency_slack(lmm_variable_t var)
878 int minslack = std::numeric_limits<int>::max();
879 for (s_lmm_element_t const& elem : var->cnsts) {
880 int slack = lmm_concurrency_slack(elem.constraint);
881 if (slack < minslack) {
882 // This is only an optimization, to avoid looking at more constraints when slack is already zero
891 /* /Check if a variable can be enabled
893 * Make sure to set staged_weight before, if your intent is only to check concurrency
895 int lmm_can_enable_var(lmm_variable_t var){
896 return var->staged_weight>0 && lmm_cnstrs_min_concurrency_slack(var)>=var->concurrency_share;
899 //Small remark: In this implementation of lmm_enable_var and lmm_disable_var, we will meet multiple times with var when
900 // running lmm_update_modified_set.
901 //A priori not a big performance issue, but we might do better by calling lmm_update_modified_set within the for loops
902 // (after doing the first for enabling==1, and before doing the last for disabling==1)
903 void lmm_enable_var(lmm_system_t sys, lmm_variable_t var){
904 xbt_assert(not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug) || lmm_can_enable_var(var));
906 var->sharing_weight = var->staged_weight;
907 var->staged_weight = 0;
909 // Enabling the variable, move to var to list head. Subtlety is: here, we need to call lmm_update_modified_set AFTER
910 // moving at least one element of var.
912 xbt_swag_remove(var, &(sys->variable_set));
913 xbt_swag_insert_at_head(var, &(sys->variable_set));
914 for (s_lmm_element_t& elem : var->cnsts) {
915 xbt_swag_remove(&elem, &(elem.constraint->disabled_element_set));
916 xbt_swag_insert_at_head(&elem, &(elem.constraint->enabled_element_set));
917 lmm_increase_concurrency(&elem);
919 if (not var->cnsts.empty())
920 lmm_update_modified_set(sys, var->cnsts[0].constraint);
922 //When used within lmm_on_disabled_var, we would get an assertion fail, because transiently there can be variables
923 // that are staged and could be activated.
924 //Anyway, caller functions all call lmm_check_concurrency() in the end.
927 void lmm_disable_var(lmm_system_t sys, lmm_variable_t var){
928 xbt_assert(not var->staged_weight, "Staged weight should have been cleared");
929 // Disabling the variable, move to var to list tail. Subtlety is: here, we need to call lmm_update_modified_set BEFORE
930 // moving the last element of var.
931 xbt_swag_remove(var, &(sys->variable_set));
932 xbt_swag_insert_at_tail(var, &(sys->variable_set));
933 if (not var->cnsts.empty())
934 lmm_update_modified_set(sys, var->cnsts[0].constraint);
935 for (s_lmm_element_t& elem : var->cnsts) {
936 xbt_swag_remove(&elem, &(elem.constraint->enabled_element_set));
937 xbt_swag_insert_at_tail(&elem, &(elem.constraint->disabled_element_set));
939 xbt_swag_remove(&elem, &(elem.constraint->active_element_set));
941 lmm_decrease_concurrency(&elem);
944 var->sharing_weight = 0.0;
945 var->staged_weight=0.0;
947 lmm_check_concurrency(sys);
950 /* /brief Find variables that can be enabled and enable them.
952 * Assuming that the variable has already been removed from non-zero weights
953 * Can we find a staged variable to add?
954 * If yes, check that none of the constraints that this variable is involved in is at the limit of its concurrency
955 * And then add it to enabled variables
957 void lmm_on_disabled_var(lmm_system_t sys, lmm_constraint_t cnstr){
959 if(cnstr->concurrency_limit<0)
962 int numelem = xbt_swag_size(&(cnstr->disabled_element_set));
966 lmm_element_t elem = (lmm_element_t)xbt_swag_getFirst(&(cnstr->disabled_element_set));
968 //Cannot use xbt_swag_foreach, because lmm_enable_var will modify disabled_element_set.. within the loop
969 while (numelem-- && elem) {
971 lmm_element_t nextelem = (lmm_element_t)xbt_swag_getNext(elem, cnstr->disabled_element_set.offset);
973 if (elem->variable->staged_weight > 0 && lmm_can_enable_var(elem->variable)) {
974 //Found a staged variable
975 //TODOLATER: Add random timing function to model reservation protocol fuzziness? Then how to make sure that
976 //staged variables will eventually be called?
977 lmm_enable_var(sys, elem->variable);
980 xbt_assert(cnstr->concurrency_current<=cnstr->concurrency_limit,"Concurrency overflow!");
981 if(cnstr->concurrency_current==cnstr->concurrency_limit)
987 //We could get an assertion fail, because transiently there can be variables that are staged and could be activated.
988 //And we need to go through all constraints of the disabled var before getting back a coherent state.
989 //Anyway, caller functions all call lmm_check_concurrency() in the end.
992 /* \brief update the weight of a variable, and enable/disable it.
993 * @return Returns whether a change was made
995 void lmm_update_variable_weight(lmm_system_t sys, lmm_variable_t var, double weight)
997 xbt_assert(weight>=0,"Variable weight should not be negative!");
999 if (weight == var->sharing_weight)
1002 int enabling_var = (weight > 0 && var->sharing_weight <= 0);
1003 int disabling_var = (weight <= 0 && var->sharing_weight > 0);
1005 XBT_IN("(sys=%p, var=%p, weight=%f)", sys, var, weight);
1009 //Are we enabling this variable?
1011 var->staged_weight = weight;
1012 int minslack = lmm_cnstrs_min_concurrency_slack(var);
1013 if (minslack < var->concurrency_share) {
1014 XBT_DEBUG("Staging var (instead of enabling) because min concurrency slack %i, with weight %f and concurrency"
1015 " share %i", minslack, weight, var->concurrency_share);
1018 XBT_DEBUG("Enabling var with min concurrency slack %i", minslack);
1019 lmm_enable_var(sys,var);
1020 } else if (disabling_var){
1021 //Are we disabling this variable?
1022 lmm_disable_var(sys,var);
1024 var->sharing_weight = weight;
1027 lmm_check_concurrency(sys);
1032 double lmm_get_variable_weight(lmm_variable_t var)
1034 return var->sharing_weight;
1037 void lmm_update_constraint_bound(lmm_system_t sys, lmm_constraint_t cnst, double bound)
1040 lmm_update_modified_set(sys, cnst);
1041 cnst->bound = bound;
1044 int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
1046 return xbt_swag_belongs(cnst, &(sys->active_constraint_set));
1049 /** \brief Update the constraint set propagating recursively to other constraints so the system should not be entirely
1052 * \param sys the lmm_system_t
1053 * \param cnst the lmm_constraint_t affected by the change
1055 * A recursive algorithm to optimize the system recalculation selecting only constraints that have changed. Each
1056 * constraint change is propagated to the list of constraints for each variable.
1058 static void lmm_update_modified_set_rec(lmm_system_t sys, lmm_constraint_t cnst)
1062 xbt_swag_foreach(_elem, &cnst->enabled_element_set) {
1063 lmm_variable_t var = ((lmm_element_t)_elem)->variable;
1064 for (s_lmm_element_t const& elem : var->cnsts) {
1065 if (var->visited == sys->visited_counter)
1067 if (elem.constraint != cnst && not xbt_swag_belongs(elem.constraint, &sys->modified_constraint_set)) {
1068 xbt_swag_insert(elem.constraint, &sys->modified_constraint_set);
1069 lmm_update_modified_set_rec(sys, elem.constraint);
1072 //var will be ignored in later visits as long as sys->visited_counter does not move
1073 var->visited = sys->visited_counter;
1077 static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst)
1079 /* nothing to do if selective update isn't active */
1080 if (sys->selective_update_active && not xbt_swag_belongs(cnst, &sys->modified_constraint_set)) {
1081 xbt_swag_insert(cnst, &sys->modified_constraint_set);
1082 lmm_update_modified_set_rec(sys, cnst);
1086 /** \brief Remove all constraints of the modified_constraint_set.
1088 * \param sys the lmm_system_t
1090 static void lmm_remove_all_modified_set(lmm_system_t sys)
1092 // We cleverly un-flag all variables just by incrementing sys->visited_counter
1093 // In effect, the var->visited value will no more be equal to sys->visited counter
1094 // To be clean, when visited counter has wrapped around, we force these var->visited values so that variables that
1095 // were in the modified a long long time ago are not wrongly skipped here, which would lead to very nasty bugs
1096 // (i.e. not readibily reproducible, and requiring a lot of run time before happening).
1097 if (++sys->visited_counter == 1) {
1098 /* the counter wrapped around, reset each variable->visited */
1100 xbt_swag_foreach(_var, &sys->variable_set)
1101 ((lmm_variable_t)_var)->visited = 0;
1103 xbt_swag_reset(&sys->modified_constraint_set);
1107 * Returns resource load (in flop per second, or byte per second, or similar)
1109 * If the resource is shared (the default case), the load is sum of resource usage made by every variables located on
1112 * If the resource is not shared (ie in FATPIPE mode), then the load is the max (not the sum) of all resource usages
1113 * located on this resource.
1115 * \param cnst the lmm_constraint_t associated to the resource
1117 double lmm_constraint_get_usage(lmm_constraint_t cnst) {
1119 xbt_swag_t elem_list = &(cnst->enabled_element_set);
1122 xbt_swag_foreach(_elem, elem_list)
1124 lmm_element_t elem = (lmm_element_t)_elem;
1125 if (elem->consumption_weight > 0) {
1126 if (cnst->sharing_policy)
1127 usage += elem->consumption_weight * elem->variable->value;
1128 else if (usage < elem->consumption_weight * elem->variable->value)
1129 usage = std::max(usage, elem->consumption_weight * elem->variable->value);
1135 int lmm_constraint_get_variable_amount(lmm_constraint_t cnst) {
1137 xbt_swag_t elem_list = &(cnst->enabled_element_set);
1140 xbt_swag_foreach(_elem, elem_list) {
1141 lmm_element_t elem = (lmm_element_t)_elem;
1142 if (elem->consumption_weight > 0)