X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/265e908745398dd4e9cc55187aa267650468c57c..5ed37babb2fa9097abe82df299c0aa259ed84d5a:/src/kernel/lmm/maxmin.cpp

diff --git a/src/kernel/lmm/maxmin.cpp b/src/kernel/lmm/maxmin.cpp
index 8bd4ecad4b..7cbe6cf695 100644
--- a/src/kernel/lmm/maxmin.cpp
+++ b/src/kernel/lmm/maxmin.cpp
@@ -1,401 +1,15 @@
-/* Copyright (c) 2004-2018. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2004-2023. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
-/* \file callbacks.h */
-
 #include "src/kernel/lmm/maxmin.hpp"
-#include "xbt/backtrace.hpp"
-#include "xbt/log.h"
-#include "xbt/mallocator.h"
-#include "xbt/sysdep.h"
-#include "xbt/utility.hpp"
-#include <algorithm>
-#include <cmath>
-#include <cstdlib>
-#include <cxxabi.h>
-#include <limits>
-#include <vector>
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_maxmin, surf, "Logging specific to SURF (maxmin)");
-
-double sg_maxmin_precision = 0.00001; /* Change this with --cfg=maxmin/precision:VALUE */
-double sg_surf_precision   = 0.00001; /* Change this with --cfg=surf/precision:VALUE */
-int sg_concurrency_limit   = -1;      /* Change this with --cfg=maxmin/concurrency-limit:VALUE */
-
-namespace simgrid {
-namespace kernel {
-namespace lmm {
-
-typedef std::vector<int> dyn_light_t;
-
-int Variable::Global_debug_id   = 1;
-int Constraint::Global_debug_id = 1;
-
-int Element::get_concurrency() const
-{
-  // Ignore element with weight less than one (e.g. cross-traffic)
-  return (consumption_weight >= 1) ? 1 : 0;
-  // There are other alternatives, but they will change the behaviour of the model..
-  // So do not use it unless you want to make a new model.
-  // If you do, remember to change the variables concurrency share to reflect it.
-  // Potential examples are:
-  // return (elem->weight>0)?1:0;//Include element as soon  as weight is non-zero
-  // return (int)ceil(elem->weight);//Include element as the rounded-up integer value of the element weight
-}
-
-void Element::decrease_concurrency()
-{
-  xbt_assert(constraint->concurrency_current >= get_concurrency());
-  constraint->concurrency_current -= get_concurrency();
-}
-
-void Element::increase_concurrency()
-{
-  constraint->concurrency_current += get_concurrency();
-
-  if (constraint->concurrency_current > constraint->concurrency_maximum)
-    constraint->concurrency_maximum = constraint->concurrency_current;
-
-  xbt_assert(constraint->get_concurrency_limit() < 0 ||
-                 constraint->concurrency_current <= constraint->get_concurrency_limit(),
-             "Concurrency limit overflow!");
-}
-
-void System::check_concurrency() const
-{
-  // These checks are very expensive, so do them only if we want to debug SURF LMM
-  if (not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug))
-    return;
-
-  for (Constraint const& cnst : constraint_set) {
-    int concurrency       = 0;
-    for (Element const& elem : cnst.enabled_element_set) {
-      xbt_assert(elem.variable->sharing_weight > 0);
-      concurrency += elem.get_concurrency();
-    }
-
-    for (Element const& elem : cnst.disabled_element_set) {
-      // We should have staged variables only if concurrency is reached in some constraint
-      xbt_assert(cnst.get_concurrency_limit() < 0 || elem.variable->staged_weight == 0 ||
-                     elem.variable->get_min_concurrency_slack() < elem.variable->concurrency_share,
-                 "should not have staged variable!");
-    }
-
-    xbt_assert(cnst.get_concurrency_limit() < 0 || cnst.get_concurrency_limit() >= concurrency,
-               "concurrency check failed!");
-    xbt_assert(cnst.concurrency_current == concurrency, "concurrency_current is out-of-date!");
-  }
-
-  // Check that for each variable, all corresponding elements are in the same state (i.e. same element sets)
-  for (Variable const& var : variable_set) {
-    if (var.cnsts.empty())
-      continue;
-
-    const Element& elem    = var.cnsts[0];
-    int belong_to_enabled  = elem.enabled_element_set_hook.is_linked();
-    int belong_to_disabled = elem.disabled_element_set_hook.is_linked();
-    int belong_to_active   = elem.active_element_set_hook.is_linked();
-
-    for (Element const& elem2 : var.cnsts) {
-      xbt_assert(belong_to_enabled == elem2.enabled_element_set_hook.is_linked(),
-                 "Variable inconsistency (1): enabled_element_set");
-      xbt_assert(belong_to_disabled == elem2.disabled_element_set_hook.is_linked(),
-                 "Variable inconsistency (2): disabled_element_set");
-      xbt_assert(belong_to_active == elem2.active_element_set_hook.is_linked(),
-                 "Variable inconsistency (3): active_element_set");
-    }
-  }
-}
-
-void System::var_free(Variable* var)
-{
-  XBT_IN("(sys=%p, var=%p)", this, var);
-  modified = true;
-
-  // TODOLATER Can do better than that by leaving only the variable in only one enabled_element_set, call
-  // update_modified_set, and then remove it..
-  if (not var->cnsts.empty())
-    update_modified_set(var->cnsts[0].constraint);
-
-  for (Element& elem : var->cnsts) {
-    if (var->sharing_weight > 0)
-      elem.decrease_concurrency();
-    if (elem.enabled_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->enabled_element_set, elem);
-    if (elem.disabled_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->disabled_element_set, elem);
-    if (elem.active_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->active_element_set, elem);
-    int nelements = elem.constraint->enabled_element_set.size() + elem.constraint->disabled_element_set.size();
-    if (nelements == 0)
-      make_constraint_inactive(elem.constraint);
-    else
-      on_disabled_var(elem.constraint);
-  }
-
-  var->cnsts.clear();
-
-  check_concurrency();
-
-  xbt_mallocator_release(variable_mallocator, var);
-  XBT_OUT();
-}
-
-System::System(bool selective_update) : selective_update_active(selective_update)
-{
-  modified        = false;
-  visited_counter = 1;
-
-  XBT_DEBUG("Setting selective_update_active flag to %d", selective_update_active);
-
-  variable_mallocator =
-      xbt_mallocator_new(65536, System::variable_mallocator_new_f, System::variable_mallocator_free_f, nullptr);
-  solve_fun = &lmm_solve;
-}
-
-System::~System()
-{
-  Variable* var;
-  Constraint* cnst;
-
-  while ((var = extract_variable())) {
-    auto demangled = simgrid::xbt::demangle(typeid(*var->id).name());
-    XBT_WARN("Probable bug: a %s variable (#%d) not removed before the LMM system destruction.", demangled.get(),
-             var->id_int);
-    var_free(var);
-  }
-  while ((cnst = extract_constraint()))
-    cnst_free(cnst);
-
-  xbt_mallocator_free(variable_mallocator);
-  delete modified_set_;
-}
-
-void System::cnst_free(Constraint* cnst)
-{
-  make_constraint_inactive(cnst);
-  delete cnst;
-}
-
-Constraint::Constraint(void* id_value, double bound_value) : bound(bound_value), id(id_value)
-{
-  id_int = Global_debug_id++;
-
-  remaining           = 0.0;
-  usage               = 0.0;
-  concurrency_limit   = sg_concurrency_limit;
-  concurrency_current = 0;
-  concurrency_maximum = 0;
-  sharing_policy      = 1; /* FIXME: don't hardcode the value */
-
-  lambda     = 0.0;
-  new_lambda = 0.0;
-  cnst_light = nullptr;
-}
-
-Constraint* System::constraint_new(void* id, double bound_value)
-{
-  Constraint* cnst = new Constraint(id, bound_value);
-  insert_constraint(cnst);
-  return cnst;
-}
-
-void* System::variable_mallocator_new_f()
-{
-  return new Variable;
-}
-
-void System::variable_mallocator_free_f(void* var)
-{
-  delete static_cast<Variable*>(var);
-}
-
-Variable* System::variable_new(simgrid::kernel::resource::Action* id, double sharing_weight, double bound,
-                               int number_of_constraints)
-{
-  XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)", this, id, sharing_weight, bound, number_of_constraints);
-
-  Variable* var = static_cast<Variable*>(xbt_mallocator_get(variable_mallocator));
-  var->initialize(id, sharing_weight, bound, number_of_constraints, visited_counter - 1);
-  if (sharing_weight)
-    variable_set.push_front(*var);
-  else
-    variable_set.push_back(*var);
-
-  XBT_OUT(" returns %p", var);
-  return var;
-}
-
-void System::variable_free(Variable* var)
-{
-  remove_variable(var);
-  var_free(var);
-}
-
-void System::expand(Constraint* cnst, Variable* var, double consumption_weight)
-{
-  modified = true;
-
-  // Check if this variable already has an active element in this constraint
-  // If it does, substract it from the required slack
-  int current_share = 0;
-  if (var->concurrency_share > 1) {
-    for (Element& elem : var->cnsts) {
-      if (elem.constraint == cnst && elem.enabled_element_set_hook.is_linked())
-        current_share += elem.get_concurrency();
-    }
-  }
-
-  // Check if we need to disable the variable
-  if (var->sharing_weight > 0 && var->concurrency_share - current_share > cnst->get_concurrency_slack()) {
-    double weight = var->sharing_weight;
-    disable_var(var);
-    for (Element const& elem : var->cnsts)
-      on_disabled_var(elem.constraint);
-    consumption_weight = 0;
-    var->staged_weight = weight;
-    xbt_assert(not var->sharing_weight);
-  }
 
-  xbt_assert(var->cnsts.size() < var->cnsts.capacity(), "Too much constraints");
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(ker_lmm);
 
-  var->cnsts.resize(var->cnsts.size() + 1);
-  Element& elem = var->cnsts.back();
+namespace simgrid::kernel::lmm {
 
-  elem.consumption_weight = consumption_weight;
-  elem.constraint         = cnst;
-  elem.variable           = var;
-
-  if (var->sharing_weight) {
-    elem.constraint->enabled_element_set.push_front(elem);
-    elem.increase_concurrency();
-  } else
-    elem.constraint->disabled_element_set.push_back(elem);
-
-  if (not selective_update_active) {
-    make_constraint_active(cnst);
-  } else if (elem.consumption_weight > 0 || var->sharing_weight > 0) {
-    make_constraint_active(cnst);
-    update_modified_set(cnst);
-    // TODOLATER: Why do we need this second call?
-    if (var->cnsts.size() > 1)
-      update_modified_set(var->cnsts[0].constraint);
-  }
-
-  check_concurrency();
-}
-
-void System::expand_add(Constraint* cnst, Variable* var, double value)
-{
-  modified = true;
-
-  check_concurrency();
-
-  // BEWARE: In case you have multiple elements in one constraint, this will always add value to the first element.
-  auto elem_it =
-      std::find_if(begin(var->cnsts), end(var->cnsts), [&cnst](Element const& x) { return x.constraint == cnst; });
-  if (elem_it != end(var->cnsts)) {
-    Element& elem = *elem_it;
-    if (var->sharing_weight)
-      elem.decrease_concurrency();
-
-    if (cnst->sharing_policy)
-      elem.consumption_weight += value;
-    else
-      elem.consumption_weight = std::max(elem.consumption_weight, value);
-
-    // We need to check that increasing value of the element does not cross the concurrency limit
-    if (var->sharing_weight) {
-      if (cnst->get_concurrency_slack() < elem.get_concurrency()) {
-        double weight = var->sharing_weight;
-        disable_var(var);
-        for (Element const& elem2 : var->cnsts)
-          on_disabled_var(elem2.constraint);
-        var->staged_weight = weight;
-        xbt_assert(not var->sharing_weight);
-      }
-      elem.increase_concurrency();
-    }
-    update_modified_set(cnst);
-  } else
-    expand(cnst, var, value);
-
-  check_concurrency();
-}
-
-Variable* Constraint::get_variable(const_lmm_element_t* elem) const
-{
-  if (*elem == nullptr) {
-    // That is the first call, pick the first element among enabled_element_set (or disabled_element_set if
-    // enabled_element_set is empty)
-    if (not enabled_element_set.empty())
-      *elem = &enabled_element_set.front();
-    else if (not disabled_element_set.empty())
-      *elem = &disabled_element_set.front();
-    else
-      *elem = nullptr;
-  } else {
-    // elem is not null, so we carry on
-    if ((*elem)->enabled_element_set_hook.is_linked()) {
-      // Look at enabled_element_set, and jump to disabled_element_set when finished
-      auto iter = std::next(enabled_element_set.iterator_to(**elem));
-      if (iter != std::end(enabled_element_set))
-        *elem = &*iter;
-      else if (not disabled_element_set.empty())
-        *elem = &disabled_element_set.front();
-      else
-        *elem = nullptr;
-    } else {
-      auto iter = std::next(disabled_element_set.iterator_to(**elem));
-      *elem     = iter != std::end(disabled_element_set) ? &*iter : nullptr;
-    }
-  }
-  if (*elem)
-    return (*elem)->variable;
-  else
-    return nullptr;
-}
-
-// if we modify the list between calls, normal version may loop forever
-// this safe version ensures that we browse the list elements only once
-Variable* Constraint::get_variable_safe(const_lmm_element_t* elem, const_lmm_element_t* nextelem, int* numelem) const
-{
-  if (*elem == nullptr) {
-    *numelem = enabled_element_set.size() + disabled_element_set.size() - 1;
-    if (not enabled_element_set.empty())
-      *elem = &enabled_element_set.front();
-    else if (not disabled_element_set.empty())
-      *elem = &disabled_element_set.front();
-    else
-      *elem = nullptr;
-  } else {
-    *elem = *nextelem;
-    if (*numelem > 0) {
-      (*numelem)--;
-    } else
-      return nullptr;
-  }
-  if (*elem) {
-    // elem is not null, so we carry on
-    if ((*elem)->enabled_element_set_hook.is_linked()) {
-      // Look at enabled_element_set, and jump to disabled_element_set when finished
-      auto iter = std::next(enabled_element_set.iterator_to(**elem));
-      if (iter != std::end(enabled_element_set))
-        *nextelem = &*iter;
-      else if (not disabled_element_set.empty())
-        *nextelem = &disabled_element_set.front();
-      else
-        *nextelem = nullptr;
-    } else {
-      auto iter = std::next(disabled_element_set.iterator_to(**elem));
-      *nextelem = iter != std::end(disabled_element_set) ? &*iter : nullptr;
-    }
-    return (*elem)->variable;
-  } else
-    return nullptr;
-}
+using dyn_light_t = std::vector<int>;
 
 static inline void saturated_constraints_update(double usage, int cnst_light_num, dyn_light_t& saturated_constraints,
                                                 double* min_usage)
@@ -411,146 +25,78 @@ static inline void saturated_constraints_update(double usage, int cnst_light_num
   }
 }
 
-static inline void saturated_variable_set_update(ConstraintLight* cnst_light_tab,
+static inline void saturated_variable_set_update(const ConstraintLight* cnst_light_tab,
                                                  const dyn_light_t& saturated_constraints, System* sys)
 {
   /* Add active variables (i.e. variables that need to be set) from the set of constraints to saturate
    * (cnst_light_tab)*/
   for (int const& saturated_cnst : saturated_constraints) {
-    ConstraintLight& cnst = cnst_light_tab[saturated_cnst];
-    for (Element const& elem : cnst.cnst->active_element_set) {
-      // Visiting active_element_set, so, by construction, should never get a zero weight, correct?
-      xbt_assert(elem.variable->sharing_weight > 0);
-      if (elem.consumption_weight > 0 && not elem.variable->saturated_variable_set_hook.is_linked())
+    const ConstraintLight& cnst = cnst_light_tab[saturated_cnst];
+    for (Element const& elem : cnst.cnst->active_element_set_) {
+      xbt_assert(elem.variable->sharing_penalty_ > 0); // All elements of active_element_set should be active
+      if (elem.consumption_weight > 0 && not elem.variable->saturated_variable_set_hook_.is_linked())
         sys->saturated_variable_set.push_back(*elem.variable);
     }
   }
 }
 
-template <class ElemList>
-static void format_element_list(const ElemList& elem_list, int sharing_policy, double& sum, std::string& buf)
+void MaxMin::do_solve()
 {
-  for (Element const& elem : elem_list) {
-    buf += std::to_string(elem.consumption_weight) + ".'" + std::to_string(elem.variable->id_int) + "'(" +
-           std::to_string(elem.variable->value) + ")" + (sharing_policy ? " + " : " , ");
-    if (sharing_policy)
-      sum += elem.consumption_weight * elem.variable->value;
-    else
-      sum = std::max(sum, elem.consumption_weight * elem.variable->value);
-  }
-}
-
-void System::print() const
-{
-  std::string buf = std::string("MAX-MIN ( ");
-
-  /* Printing Objective */
-  for (Variable const& var : variable_set)
-    buf += "'" + std::to_string(var.id_int) + "'(" + std::to_string(var.sharing_weight) + ") ";
-  buf += ")";
-  XBT_DEBUG("%20s", buf.c_str());
-  buf.clear();
-
-  XBT_DEBUG("Constraints");
-  /* Printing Constraints */
-  for (Constraint const& cnst : active_constraint_set) {
-    double sum            = 0.0;
-    // Show  the enabled variables
-    buf += "\t";
-    buf += cnst.sharing_policy ? "(" : "max(";
-    format_element_list(cnst.enabled_element_set, cnst.sharing_policy, sum, buf);
-    // TODO: Adding disabled elements only for test compatibility, but do we really want them to be printed?
-    format_element_list(cnst.disabled_element_set, cnst.sharing_policy, sum, buf);
-
-    buf += "0) <= " + std::to_string(cnst.bound) + " ('" + std::to_string(cnst.id_int) + "')";
-
-    if (not cnst.sharing_policy) {
-      buf += " [MAX-Constraint]";
-    }
-    XBT_DEBUG("%s", buf.c_str());
-    buf.clear();
-    xbt_assert(not double_positive(sum - cnst.bound, cnst.bound * sg_maxmin_precision),
-               "Incorrect value (%f is not smaller than %f): %g", sum, cnst.bound, sum - cnst.bound);
-  }
-
-  XBT_DEBUG("Variables");
-  /* Printing Result */
-  for (Variable const& var : variable_set) {
-    if (var.bound > 0) {
-      XBT_DEBUG("'%d'(%f) : %f (<=%f)", var.id_int, var.sharing_weight, var.value, var.bound);
-      xbt_assert(not double_positive(var.value - var.bound, var.bound * sg_maxmin_precision),
-                 "Incorrect value (%f is not smaller than %f", var.value, var.bound);
-    } else {
-      XBT_DEBUG("'%d'(%f) : %f", var.id_int, var.sharing_weight, var.value);
-    }
-  }
-}
-
-void System::solve()
-{
-  if (modified) {
-    XBT_IN("(sys=%p)", this);
-    /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only
-     * constraints that changed are considered. Otherwise all constraints with active actions are considered.
-     */
-    if (selective_update_active)
-      solve(modified_constraint_set);
-    else
-      solve(active_constraint_set);
-    XBT_OUT();
-  }
+  XBT_IN("(sys=%p)", this);
+  /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only
+   * constraints that changed are considered. Otherwise all constraints with active actions are considered.
+   */
+  if (selective_update_active)
+    maxmin_solve(modified_constraint_set);
+  else
+    maxmin_solve(active_constraint_set);
+  XBT_OUT();
 }
 
-template <class CnstList> void System::solve(CnstList& cnst_list)
+template <class CnstList> void MaxMin::maxmin_solve(CnstList& cnst_list)
 {
   double min_usage = -1;
   double min_bound = -1;
 
   XBT_DEBUG("Active constraints : %zu", cnst_list.size());
-  /* Init: Only modified code portions: reset the value of active variables */
-  for (Constraint const& cnst : cnst_list) {
-    for (Element const& elem : cnst.enabled_element_set) {
-      xbt_assert(elem.variable->sharing_weight > 0.0);
-      elem.variable->value = 0.0;
-    }
-  }
-
-  ConstraintLight* cnst_light_tab = new ConstraintLight[cnst_list.size()]();
+  cnst_light_vec.reserve(cnst_list.size());
+  ConstraintLight* cnst_light_tab = cnst_light_vec.data();
   int cnst_light_num              = 0;
-  dyn_light_t saturated_constraints;
 
   for (Constraint& cnst : cnst_list) {
     /* INIT: Collect constraints that actually need to be saturated (i.e remaining  and usage are strictly positive)
      * into cnst_light_tab. */
-    cnst.remaining = cnst.bound;
-    if (not double_positive(cnst.remaining, cnst.bound * sg_maxmin_precision))
+    cnst.dynamic_bound_ = cnst.bound_;
+    if ((cnst.get_sharing_policy() == Constraint::SharingPolicy::NONLINEAR || cnst.get_sharing_policy() == Constraint::SharingPolicy::WIFI) && cnst.dyn_constraint_cb_) {
+      cnst.dynamic_bound_ = cnst.dyn_constraint_cb_(cnst.bound_, cnst.concurrency_current_);
+    }
+    cnst.remaining_ = cnst.dynamic_bound_;
+    if (not double_positive(cnst.remaining_, cnst.dynamic_bound_ * sg_maxmin_precision))
       continue;
-    cnst.usage = 0;
-    for (Element& elem : cnst.enabled_element_set) {
-      xbt_assert(elem.variable->sharing_weight > 0);
+    cnst.usage_ = 0;
+    for (Element& elem : cnst.enabled_element_set_) {
+      xbt_assert(elem.variable->sharing_penalty_ > 0.0);
+      elem.variable->value_ = 0.0;
       if (elem.consumption_weight > 0) {
-        if (cnst.sharing_policy)
-          cnst.usage += elem.consumption_weight / elem.variable->sharing_weight;
-        else if (cnst.usage < elem.consumption_weight / elem.variable->sharing_weight)
-          cnst.usage = elem.consumption_weight / elem.variable->sharing_weight;
+        if (cnst.sharing_policy_ != Constraint::SharingPolicy::FATPIPE)
+          cnst.usage_ += elem.consumption_weight / elem.variable->sharing_penalty_;
+        else if (cnst.usage_ < elem.consumption_weight / elem.variable->sharing_penalty_)
+          cnst.usage_ = elem.consumption_weight / elem.variable->sharing_penalty_;
 
         elem.make_active();
-        simgrid::kernel::resource::Action* action = static_cast<simgrid::kernel::resource::Action*>(elem.variable->id);
-        if (modified_set_ && not action->is_within_modified_set())
-          modified_set_->push_back(*action);
       }
     }
-    XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst.id_int, cnst.usage,
-              cnst.remaining, cnst.concurrency_current, cnst.concurrency_maximum, cnst.get_concurrency_limit());
+    XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst.rank_, cnst.usage_,
+              cnst.remaining_, cnst.concurrency_current_, cnst.concurrency_maximum_, cnst.get_concurrency_limit());
     /* Saturated constraints update */
 
-    if (cnst.usage > 0) {
+    if (cnst.usage_ > 0) {
       cnst_light_tab[cnst_light_num].cnst                 = &cnst;
-      cnst.cnst_light                                     = &cnst_light_tab[cnst_light_num];
-      cnst_light_tab[cnst_light_num].remaining_over_usage = cnst.remaining / cnst.usage;
+      cnst.cnst_light_                                    = &cnst_light_tab[cnst_light_num];
+      cnst_light_tab[cnst_light_num].remaining_over_usage = cnst.remaining_ / cnst.usage_;
       saturated_constraints_update(cnst_light_tab[cnst_light_num].remaining_over_usage, cnst_light_num,
                                    saturated_constraints, &min_usage);
-      xbt_assert(not cnst.active_element_set.empty(),
+      xbt_assert(not cnst.active_element_set_.empty(),
                  "There is no sense adding a constraint that has no active element!");
       cnst_light_num++;
     }
@@ -563,16 +109,16 @@ template <class CnstList> void System::solve(CnstList& cnst_list)
     /* Fix the variables that have to be */
     auto& var_list = saturated_variable_set;
     for (Variable const& var : var_list) {
-      if (var.sharing_weight <= 0.0)
+      if (var.sharing_penalty_ <= 0.0)
         DIE_IMPOSSIBLE;
       /* First check if some of these variables could reach their upper bound and update min_bound accordingly. */
-      XBT_DEBUG("var=%d, var.bound=%f, var.weight=%f, min_usage=%f, var.bound*var.weight=%f", var.id_int, var.bound,
-                var.sharing_weight, min_usage, var.bound * var.sharing_weight);
-      if ((var.bound > 0) && (var.bound * var.sharing_weight < min_usage)) {
+      XBT_DEBUG("var=%d, var.bound=%f, var.penalty=%f, min_usage=%f, var.bound*var.penalty=%f", var.rank_, var.bound_,
+                var.sharing_penalty_, min_usage, var.bound_ * var.sharing_penalty_);
+      if ((var.bound_ > 0) && (var.bound_ * var.sharing_penalty_ < min_usage)) {
         if (min_bound < 0)
-          min_bound = var.bound * var.sharing_weight;
+          min_bound = var.bound_ * var.sharing_penalty_;
         else
-          min_bound = std::min(min_bound, (var.bound * var.sharing_weight));
+          min_bound = std::min(min_bound, (var.bound_ * var.sharing_penalty_));
         XBT_DEBUG("Updated min_bound=%f", min_bound);
       }
     }
@@ -582,76 +128,81 @@ template <class CnstList> void System::solve(CnstList& cnst_list)
       if (min_bound < 0) {
         // If no variable could reach its bound, deal iteratively the constraints usage ( at worst one constraint is
         // saturated at each cycle)
-        var.value = min_usage / var.sharing_weight;
-        XBT_DEBUG("Setting var (%d) value to %f\n", var.id_int, var.value);
+        var.value_ = min_usage / var.sharing_penalty_;
+        XBT_DEBUG("Setting var (%d) value to %f\n", var.rank_, var.value_);
       } else {
         // If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
-        if (double_equals(min_bound, var.bound * var.sharing_weight, sg_maxmin_precision)) {
-          var.value = var.bound;
-          XBT_DEBUG("Setting %p (%d) value to %f\n", &var, var.id_int, var.value);
+        if (double_equals(min_bound, var.bound_ * var.sharing_penalty_, sg_maxmin_precision)) {
+          var.value_ = var.bound_;
+          XBT_DEBUG("Setting %p (%d) value to %f\n", &var, var.rank_, var.value_);
         } else {
           // Variables which bound is different are not considered for this cycle, but they will be afterwards.
-          XBT_DEBUG("Do not consider %p (%d) \n", &var, var.id_int);
+          XBT_DEBUG("Do not consider %p (%d)\n", &var, var.rank_);
           var_list.pop_front();
           continue;
         }
       }
-      XBT_DEBUG("Min usage: %f, Var(%d).weight: %f, Var(%d).value: %f ", min_usage, var.id_int, var.sharing_weight,
-                var.id_int, var.value);
+      XBT_DEBUG("Min usage: %f, Var(%d).penalty: %f, Var(%d).value: %f", min_usage, var.rank_, var.sharing_penalty_,
+                var.rank_, var.value_);
 
-      /* Update the usage of contraints where this variable is involved */
-      for (Element& elem : var.cnsts) {
+      /* Update the usage of constraints where this variable is involved */
+      for (Element& elem : var.cnsts_) {
         Constraint* cnst = elem.constraint;
-        if (cnst->sharing_policy) {
+        if (cnst->sharing_policy_ != Constraint::SharingPolicy::FATPIPE) {
           // Remember: shared constraints require that sum(elem.value * var.value) < cnst->bound
-          double_update(&(cnst->remaining), elem.consumption_weight * var.value, cnst->bound * sg_maxmin_precision);
-          double_update(&(cnst->usage), elem.consumption_weight / var.sharing_weight, sg_maxmin_precision);
+          double_update(&(cnst->remaining_), elem.consumption_weight * var.value_,
+                        cnst->dynamic_bound_ * sg_maxmin_precision);
+          double_update(&(cnst->usage_), elem.consumption_weight / var.sharing_penalty_, sg_maxmin_precision);
           // If the constraint is saturated, remove it from the set of active constraints (light_tab)
-          if (not double_positive(cnst->usage, sg_maxmin_precision) ||
-              not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
-            if (cnst->cnst_light) {
-              int index = (cnst->cnst_light - cnst_light_tab);
-              XBT_DEBUG("index: %d \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f  ", index,
-                        cnst_light_num, cnst->usage, cnst->remaining, cnst->bound);
-              cnst_light_tab[index]                  = cnst_light_tab[cnst_light_num - 1];
-              cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
+          if (not double_positive(cnst->usage_, sg_maxmin_precision) ||
+              not double_positive(cnst->remaining_, cnst->dynamic_bound_ * sg_maxmin_precision)) {
+            if (cnst->cnst_light_) {
+              size_t index = (cnst->cnst_light_ - cnst_light_tab);
+              XBT_DEBUG("index: %zu \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f", index,
+                        cnst_light_num, cnst->usage_, cnst->remaining_, cnst->dynamic_bound_);
+              cnst_light_tab[index]                   = cnst_light_tab[cnst_light_num - 1];
+              cnst_light_tab[index].cnst->cnst_light_ = &cnst_light_tab[index];
               cnst_light_num--;
-              cnst->cnst_light = nullptr;
+              cnst->cnst_light_ = nullptr;
             }
           } else {
-            cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
+            if (cnst->cnst_light_) {
+              cnst->cnst_light_->remaining_over_usage = cnst->remaining_ / cnst->usage_;
+            }
           }
           elem.make_inactive();
         } else {
           // Remember: non-shared constraints only require that max(elem.value * var.value) < cnst->bound
-          cnst->usage = 0.0;
+          cnst->usage_ = 0.0;
           elem.make_inactive();
-          for (Element& elem2 : cnst->enabled_element_set) {
-            xbt_assert(elem2.variable->sharing_weight > 0);
-            if (elem2.variable->value > 0)
+          for (const Element& elem2 : cnst->enabled_element_set_) {
+            xbt_assert(elem2.variable->sharing_penalty_ > 0);
+            if (elem2.variable->value_ > 0)
               continue;
             if (elem2.consumption_weight > 0)
-              cnst->usage = std::max(cnst->usage, elem2.consumption_weight / elem2.variable->sharing_weight);
+              cnst->usage_ = std::max(cnst->usage_, elem2.consumption_weight / elem2.variable->sharing_penalty_);
           }
           // If the constraint is saturated, remove it from the set of active constraints (light_tab)
-          if (not double_positive(cnst->usage, sg_maxmin_precision) ||
-              not double_positive(cnst->remaining, cnst->bound * sg_maxmin_precision)) {
-            if (cnst->cnst_light) {
-              int index = (cnst->cnst_light - cnst_light_tab);
-              XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
-                        "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f  ",
-                        index, cnst_light_num, cnst, cnst->cnst_light, cnst_light_tab, cnst->usage, cnst->remaining,
-                        cnst->bound);
-              cnst_light_tab[index]                  = cnst_light_tab[cnst_light_num - 1];
-              cnst_light_tab[index].cnst->cnst_light = &cnst_light_tab[index];
+          if (not double_positive(cnst->usage_, sg_maxmin_precision) ||
+              not double_positive(cnst->remaining_, cnst->dynamic_bound_ * sg_maxmin_precision)) {
+            if (cnst->cnst_light_) {
+              size_t index = (cnst->cnst_light_ - cnst_light_tab);
+              XBT_DEBUG("index: %zu \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
+                        "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f",
+                        index, cnst_light_num, cnst, cnst->cnst_light_, cnst_light_tab, cnst->usage_, cnst->remaining_,
+                        cnst->dynamic_bound_);
+              cnst_light_tab[index]                   = cnst_light_tab[cnst_light_num - 1];
+              cnst_light_tab[index].cnst->cnst_light_ = &cnst_light_tab[index];
               cnst_light_num--;
-              cnst->cnst_light = nullptr;
+              cnst->cnst_light_ = nullptr;
             }
           } else {
-            cnst->cnst_light->remaining_over_usage = cnst->remaining / cnst->usage;
-            xbt_assert(not cnst->active_element_set.empty(),
-                       "Should not keep a maximum constraint that has no active"
-                       " element! You want to check the maxmin precision and possible rounding effects.");
+            if (cnst->cnst_light_) {
+              cnst->cnst_light_->remaining_over_usage = cnst->remaining_ / cnst->usage_;
+              xbt_assert(not cnst->active_element_set_.empty(),
+                         "Should not keep a maximum constraint that has no active"
+                         " element! You want to check the maxmin precision and possible rounding effects.");
+            }
           }
         }
       }
@@ -662,319 +213,18 @@ template <class CnstList> void System::solve(CnstList& cnst_list)
     min_usage = -1;
     min_bound = -1;
     saturated_constraints.clear();
-    int pos;
-    for (pos = 0; pos < cnst_light_num; pos++) {
-      xbt_assert(not cnst_light_tab[pos].cnst->active_element_set.empty(),
+    for (int pos = 0; pos < cnst_light_num; pos++) {
+      xbt_assert(not cnst_light_tab[pos].cnst->active_element_set_.empty(),
                  "Cannot saturate more a constraint that has"
                  " no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>)"
                  " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
                  "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
-                 cnst_light_tab[pos].cnst->usage, sg_maxmin_precision, cnst_light_tab[pos - 1].cnst->usage);
+                 cnst_light_tab[pos].cnst->usage_, sg_maxmin_precision, cnst_light_tab[pos - 1].cnst->usage_);
       saturated_constraints_update(cnst_light_tab[pos].remaining_over_usage, pos, saturated_constraints, &min_usage);
     }
 
     saturated_variable_set_update(cnst_light_tab, saturated_constraints, this);
-
   } while (cnst_light_num > 0);
-
-  modified = false;
-  if (selective_update_active)
-    remove_all_modified_set();
-
-  if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
-    print();
-  }
-
-  check_concurrency();
-
-  delete[] cnst_light_tab;
-}
-
-void lmm_solve(System* sys)
-{
-  sys->solve();
-}
-
-/** \brief Attribute the value bound to var->bound.
- *
- *  \param var the Variable*
- *  \param bound the new bound to associate with var
- *
- *  Makes var->bound equal to bound. Whenever this function is called a change is  signed in the system. To
- *  avoid false system changing detection it is a good idea to test (bound != 0) before calling it.
- */
-void System::update_variable_bound(Variable* var, double bound)
-{
-  modified   = true;
-  var->bound = bound;
-
-  if (not var->cnsts.empty())
-    update_modified_set(var->cnsts[0].constraint);
-}
-
-void Variable::initialize(simgrid::kernel::resource::Action* id_value, double sharing_weight_value, double bound_value,
-                          int number_of_constraints, unsigned visited_value)
-{
-  id     = id_value;
-  id_int = Global_debug_id++;
-  cnsts.reserve(number_of_constraints);
-  sharing_weight    = sharing_weight_value;
-  staged_weight     = 0.0;
-  bound             = bound_value;
-  concurrency_share = 1;
-  value             = 0.0;
-  visited           = visited_value;
-  mu                = 0.0;
-  new_mu            = 0.0;
-  func_f            = func_f_def;
-  func_fp           = func_fp_def;
-  func_fpi          = func_fpi_def;
-
-  xbt_assert(not variable_set_hook.is_linked());
-  xbt_assert(not saturated_variable_set_hook.is_linked());
-}
-
-int Variable::get_min_concurrency_slack() const
-{
-  int minslack = std::numeric_limits<int>::max();
-  for (Element const& elem : cnsts) {
-    int slack = elem.constraint->get_concurrency_slack();
-    if (slack < minslack) {
-      // This is only an optimization, to avoid looking at more constraints when slack is already zero
-      if (slack == 0)
-        return 0;
-      minslack = slack;
-    }
-  }
-  return minslack;
-}
-
-// Small remark: In this implementation of System::enable_var() and System::disable_var(), we will meet multiple times
-// with var when running System::update_modified_set().
-// A priori not a big performance issue, but we might do better by calling System::update_modified_set() within the for
-// loops (after doing the first for enabling==1, and before doing the last for disabling==1)
-void System::enable_var(Variable* var)
-{
-  xbt_assert(not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug) || var->can_enable());
-
-  var->sharing_weight = var->staged_weight;
-  var->staged_weight  = 0;
-
-  // Enabling the variable, move var to list head. Subtlety is: here, we need to call update_modified_set AFTER
-  // moving at least one element of var.
-
-  simgrid::xbt::intrusive_erase(variable_set, *var);
-  variable_set.push_front(*var);
-  for (Element& elem : var->cnsts) {
-    simgrid::xbt::intrusive_erase(elem.constraint->disabled_element_set, elem);
-    elem.constraint->enabled_element_set.push_front(elem);
-    elem.increase_concurrency();
-  }
-  if (not var->cnsts.empty())
-    update_modified_set(var->cnsts[0].constraint);
-
-  // When used within on_disabled_var, we would get an assertion fail, because transiently there can be variables
-  // that are staged and could be activated.
-  // Anyway, caller functions all call check_concurrency() in the end.
 }
 
-void System::disable_var(Variable* var)
-{
-  xbt_assert(not var->staged_weight, "Staged weight should have been cleared");
-  // Disabling the variable, move to var to list tail. Subtlety is: here, we need to call update_modified_set
-  // BEFORE moving the last element of var.
-  simgrid::xbt::intrusive_erase(variable_set, *var);
-  variable_set.push_back(*var);
-  if (not var->cnsts.empty())
-    update_modified_set(var->cnsts[0].constraint);
-  for (Element& elem : var->cnsts) {
-    simgrid::xbt::intrusive_erase(elem.constraint->enabled_element_set, elem);
-    elem.constraint->disabled_element_set.push_back(elem);
-    if (elem.active_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->active_element_set, elem);
-    elem.decrease_concurrency();
-  }
-
-  var->sharing_weight = 0.0;
-  var->staged_weight  = 0.0;
-  var->value          = 0.0;
-  check_concurrency();
-}
-
-/* /brief Find variables that can be enabled and enable them.
- *
- * Assuming that the variable has already been removed from non-zero weights
- * Can we find a staged variable to add?
- * If yes, check that none of the constraints that this variable is involved in is at the limit of its concurrency
- * And then add it to enabled variables
- */
-void System::on_disabled_var(Constraint* cnstr)
-{
-  if (cnstr->get_concurrency_limit() < 0)
-    return;
-
-  int numelem = cnstr->disabled_element_set.size();
-  if (not numelem)
-    return;
-
-  Element* elem = &cnstr->disabled_element_set.front();
-
-  // Cannot use foreach loop, because System::enable_var() will modify disabled_element_set.. within the loop
-  while (numelem-- && elem) {
-
-    Element* nextelem;
-    if (elem->disabled_element_set_hook.is_linked()) {
-      auto iter = std::next(cnstr->disabled_element_set.iterator_to(*elem));
-      nextelem  = iter != std::end(cnstr->disabled_element_set) ? &*iter : nullptr;
-    } else {
-      nextelem = nullptr;
-    }
-
-    if (elem->variable->staged_weight > 0 && elem->variable->can_enable()) {
-      // Found a staged variable
-      // TODOLATER: Add random timing function to model reservation protocol fuzziness? Then how to make sure that
-      // staged variables will eventually be called?
-      enable_var(elem->variable);
-    }
-
-    xbt_assert(cnstr->concurrency_current <= cnstr->get_concurrency_limit(), "Concurrency overflow!");
-    if (cnstr->concurrency_current == cnstr->get_concurrency_limit())
-      break;
-
-    elem = nextelem;
-  }
-
-  // We could get an assertion fail, because transiently there can be variables that are staged and could be activated.
-  // And we need to go through all constraints of the disabled var before getting back a coherent state.
-  // Anyway, caller functions all call check_concurrency() in the end.
-}
-
-/* \brief update the weight of a variable, and enable/disable it.
- * @return Returns whether a change was made
- */
-void System::update_variable_weight(Variable* var, double weight)
-{
-  xbt_assert(weight >= 0, "Variable weight should not be negative!");
-
-  if (weight == var->sharing_weight)
-    return;
-
-  int enabling_var  = (weight > 0 && var->sharing_weight <= 0);
-  int disabling_var = (weight <= 0 && var->sharing_weight > 0);
-
-  XBT_IN("(sys=%p, var=%p, weight=%f)", this, var, weight);
-
-  modified = true;
-
-  // Are we enabling this variable?
-  if (enabling_var) {
-    var->staged_weight = weight;
-    int minslack       = var->get_min_concurrency_slack();
-    if (minslack < var->concurrency_share) {
-      XBT_DEBUG("Staging var (instead of enabling) because min concurrency slack %i, with weight %f and concurrency"
-                " share %i",
-                minslack, weight, var->concurrency_share);
-      return;
-    }
-    XBT_DEBUG("Enabling var with min concurrency slack %i", minslack);
-    enable_var(var);
-  } else if (disabling_var) {
-    // Are we disabling this variable?
-    disable_var(var);
-  } else {
-    var->sharing_weight = weight;
-  }
-
-  check_concurrency();
-
-  XBT_OUT();
-}
-
-void System::update_constraint_bound(Constraint* cnst, double bound)
-{
-  modified = true;
-  update_modified_set(cnst);
-  cnst->bound = bound;
-}
-
-/** \brief Update the constraint set propagating recursively to other constraints so the system should not be entirely
- *  computed.
- *
- *  \param cnst the Constraint* affected by the change
- *
- *  A recursive algorithm to optimize the system recalculation selecting only constraints that have changed. Each
- *  constraint change is propagated to the list of constraints for each variable.
- */
-void System::update_modified_set_rec(Constraint* cnst)
-{
-  for (Element const& elem : cnst->enabled_element_set) {
-    Variable* var = elem.variable;
-    for (Element const& elem2 : var->cnsts) {
-      if (var->visited == visited_counter)
-        break;
-      if (elem2.constraint != cnst && not elem2.constraint->modified_constraint_set_hook.is_linked()) {
-        modified_constraint_set.push_back(*elem2.constraint);
-        update_modified_set_rec(elem2.constraint);
-      }
-    }
-    // var will be ignored in later visits as long as sys->visited_counter does not move
-    var->visited = visited_counter;
-  }
-}
-
-void System::update_modified_set(Constraint* cnst)
-{
-  /* nothing to do if selective update isn't active */
-  if (selective_update_active && not cnst->modified_constraint_set_hook.is_linked()) {
-    modified_constraint_set.push_back(*cnst);
-    update_modified_set_rec(cnst);
-  }
-}
-
-void System::remove_all_modified_set()
-{
-  // We cleverly un-flag all variables just by incrementing visited_counter
-  // In effect, the var->visited value will no more be equal to visited counter
-  // To be clean, when visited counter has wrapped around, we force these var->visited values so that variables that
-  // were in the modified a long long time ago are not wrongly skipped here, which would lead to very nasty bugs
-  // (i.e. not readibily reproducible, and requiring a lot of run time before happening).
-  if (++visited_counter == 1) {
-    /* the counter wrapped around, reset each variable->visited */
-    for (Variable& var : variable_set)
-      var.visited = 0;
-  }
-  modified_constraint_set.clear();
-}
-
-/**
- * Returns resource load (in flop per second, or byte per second, or similar)
- *
- * If the resource is shared (the default case), the load is sum of resource usage made by every variables located on
- * this resource.
- *
- * If the resource is not shared (ie in FATPIPE mode), then the load is the max (not the sum) of all resource usages
- * located on this resource.
- */
-double Constraint::get_usage() const
-{
-  double result              = 0.0;
-  if (sharing_policy) {
-    for (Element const& elem : enabled_element_set)
-      if (elem.consumption_weight > 0)
-        result += elem.consumption_weight * elem.variable->value;
-  } else {
-    for (Element const& elem : enabled_element_set)
-      if (elem.consumption_weight > 0)
-        result = std::max(result, elem.consumption_weight * elem.variable->value);
-  }
-  return result;
-}
-
-int Constraint::get_variable_amount() const
-{
-  return std::count_if(std::begin(enabled_element_set), std::end(enabled_element_set),
-                       [](const Element& elem) { return elem.consumption_weight > 0; });
-}
-}
-}
-}
+} // namespace simgrid::kernel::lmm