-/* Copyright (c) 2004-2022. 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. */
#include <cmath>
#include <limits>
#include <memory>
+#include <string_view>
#include <vector>
-namespace simgrid {
-namespace kernel {
-namespace lmm {
+namespace simgrid::kernel::lmm {
/** @addtogroup SURF_lmm
* @details
* - concurrency_current which is the current concurrency
* - concurrency_maximum which is the observed maximum concurrency
*
- * Variables also have one field related to concurrency: concurrency_share.
- * In effect, in some cases, one variable is involved multiple times (i.e. two elements) in a constraint.
- * For example, cross-traffic is modeled using 2 elements per constraint.
- * concurrency_share formally corresponds to the maximum number of elements that associate the variable and any given
- * constraint.
+ * Variables consumes the concurrency_limit of each constraint they are using.
+ * Each pair variable/constrainst is linked by a *single* Element object. Through this
+ * object and the respective methods (get_concurrency(), increase_concurrency() and decrease_concurrency()),
+ * the variable changes the constraint's concurrency.
+ * The amount of concurrency slack taken by each variable is determined by the Element::get_concurrency() method.
+ * At the current state, each variable counts as 1 if its consumption weight is greater than 1.
*/
/** @{ @ingroup SURF_lmm */
Element(const Element&) = default;
~Element() = default;
+ /**
+ * @brief Gets the "weight" of this element for concurrency checks.
+ *
+ * This is the amount taken by this variable of the constraint's concurrency slack
+ *
+ * @return 1 if consumption_weight greater than 1, 0 otherwise
+ */
int get_concurrency() const;
+ /**
+ * @brief Decreases the constraint's concurrency
+ *
+ * Decreases the equivalent of get_concurrency() from the constraint related to this element
+ */
void decrease_concurrency();
- void increase_concurrency();
+ /**
+ * @brief Increase constraint concurrency
+ * @param check_limit Don't check constraint concurrency overflow right now
+ */
+ void increase_concurrency(bool check_limit = true);
void make_active();
void make_inactive();
*/
class XBT_PUBLIC Constraint {
public:
- enum class SharingPolicy { NONLINEAR = 2, SHARED = 1, FATPIPE = 0 };
+ enum class SharingPolicy { WIFI = 3, NONLINEAR = 2, SHARED = 1, FATPIPE = 0 };
Constraint(resource::Resource* id_value, double bound_value);
/** @brief Get the usage of the constraint after the last lmm solve */
double get_usage() const;
- int get_variable_amount() const;
/** @brief Sets the concurrency limit for this constraint */
void set_concurrency_limit(int limit)
return concurrency_maximum_;
}
+ /**
+ * @brief Get constraint current concurrency slack
+ *
+ * This represents the "space" available for new variables in this contraint.
+ * A variable can be enabled and use this constraint if its get_concurrency() <= slack
+ *
+ * @return Constraint's slack
+ */
int get_concurrency_slack() const
{
return concurrency_limit_ < 0 ? std::numeric_limits<int>::max() : concurrency_limit_ - concurrency_current_;
/** @brief Get the maximum value of the variable (-1.0 if no specified maximum) */
double get_bound() const { return bound_; }
- /**
- * @brief Set the concurrent share of the variable
- * @param value The new concurrency share
- */
- void set_concurrency_share(short int value) { concurrency_share_ = value; }
-
/**
* @brief Get the numth constraint associated to the variable
* @param num The rank of constraint we want to get
/** @brief Check if a variable can be enabled
* Make sure to set staged_penalty before, if your intent is only to check concurrency
*/
- bool can_enable() const { return staged_penalty_ > 0 && get_min_concurrency_slack() >= concurrency_share_; }
+ bool can_enable() const { return staged_sharing_penalty_ > 0 && get_min_concurrency_slack() > 0; }
/* hookup to system */
boost::intrusive::list_member_hook<> variable_set_hook_;
// on network, the actions with higher latency have a lesser sharing_penalty
double sharing_penalty_;
- double staged_penalty_; /* If non-zero, variable is staged for addition as soon as maxconcurrency constraints will be
- met */
+ double staged_sharing_penalty_; /* If non-zero, variable is staged for addition as soon as maxconcurrency constraints
+ will be met */
double bound_;
double value_;
- short int concurrency_share_; /* The maximum number of elements that variable will add to a constraint */
resource::Action* id_;
int rank_; // Only used in debug messages to identify the variable
unsigned visited_; /* used by System::update_modified_cnst_set() */
* @param selective_update Enables lazy updates
* @return pointer to System instance
*/
- static System* build(const std::string& solver_name, bool selective_update);
+ static System* build(std::string_view solver_name, bool selective_update);
/** @brief Validates solver configuration */
static void validate_solver(const std::string& solver_name);
Variable* variable_new(resource::Action* id, double sharing_penalty, double bound = -1.0,
size_t number_of_constraints = 1);
+ /** @brief Get the list of modified actions since last solve() */
+ resource::Action::ModifiedSet* get_modified_action_set() const;
+
/**
* @brief Free a variable
* @param var The variable to free
* @param cnst A constraint
* @param var A variable
* @param value The coefficient associated to the variable in the constraint
+ * @param force_creation Force the creation of new element linking the variable to the constraint. Should be used only
+ * by the model ptask_L07 to cope with ptasks composed of flows running on the same resource (see
+ * https://framagit.org/simgrid/simgrid/-/issues/111)
*/
- void expand(Constraint * cnst, Variable * var, double value);
-
- /**
- * @brief Add value to the coefficient between a constraint and a variable or create one
- * @param cnst A constraint
- * @param var A variable
- * @param value The value to add to the coefficient associated to the variable in the constraint
- */
- void expand_add(Constraint * cnst, Variable * var, double value);
+ void expand(Constraint* cnst, Variable* var, double value, bool force_creation = false);
/** @brief Update the bound of a variable */
void update_variable_bound(Variable * var, double bound);
void enable_var(Variable * var);
void disable_var(Variable * var);
void on_disabled_var(Constraint * cnstr);
+ void check_concurrency() const;
+
+ /**
+ * @brief Auxiliary method to create a new Element which links a variable to a constraint
+ *
+ * @param cnst Constraint (resource)
+ * @param var Variable (action)
+ * @param consumption_weight how much of the resource is used for each unit of the action
+ * @return A reference to the new element
+ */
+ Element& expand_create_elem(Constraint* cnst, Variable* var, double consumption_weight);
+ /**
+ * @brief Increments the element usage
+ *
+ * @param elem Element linking variable/action to resource
+ * @param cnst Constraint (resource)
+ * @param consumption_weight how much of the resource is used for each unit of the action
+ * @return elem itself
+ */
+ Element& expand_add_to_elem(Element& elem, const Constraint* cnst, double consumption_weight) const;
/**
* @brief Update the value of element linking the constraint and the variable
void update_modified_cnst_set_from_variable(const Variable* var);
void update_modified_cnst_set(Constraint* cnst);
void update_modified_cnst_set_rec(const Constraint* cnst);
+ /** @brief Remove all constraints of the modified_constraint_set. */
+ void remove_all_modified_cnst_set();
public:
bool modified_ = false;
&Constraint::saturated_constraint_set_hook_>>
saturated_constraint_set;
- std::unique_ptr<resource::Action::ModifiedSet> modified_set_ = nullptr;
-
protected:
- bool selective_update_active; /* flag to update partially the system only selecting changed portions */
+ const bool selective_update_active; /* flag to update partially the system only selecting changed portions */
boost::intrusive::list<Constraint, boost::intrusive::member_hook<Constraint, boost::intrusive::list_member_hook<>,
&Constraint::modified_constraint_set_hook_>>
modified_constraint_set;
- /** @brief Remove all constraints of the modified_constraint_set. */
- void remove_all_modified_cnst_set();
- void check_concurrency() const;
-
private:
unsigned visited_counter_ =
1; /* used by System::update_modified_cnst_set() and System::remove_all_modified_cnst_set() to
constraint_set;
xbt_mallocator_t variable_mallocator_ =
xbt_mallocator_new(65536, System::variable_mallocator_new_f, System::variable_mallocator_free_f, nullptr);
+
+ std::unique_ptr<resource::Action::ModifiedSet> modified_set_ = nullptr;
};
/** @} */
-} // namespace lmm
-} // namespace kernel
-} // namespace simgrid
+} // namespace simgrid::kernel::lmm
-#endif
\ No newline at end of file
+#endif
