* - 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();
/**
* @brief Increase constraint concurrency
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_;