X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7249e4cde1f330ca112d22500f3cf0fb45452844..8e70d54a095cd7779a53c7a164f775f7a37b29e5:/src/kernel/lmm/System.hpp

diff --git a/src/kernel/lmm/System.hpp b/src/kernel/lmm/System.hpp
index e58e7ede06..d83ae01bad 100644
--- a/src/kernel/lmm/System.hpp
+++ b/src/kernel/lmm/System.hpp
@@ -1,4 +1,4 @@
-/* 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. */
@@ -9,7 +9,6 @@
 #include "simgrid/kernel/resource/Action.hpp"
 #include "simgrid/kernel/resource/Model.hpp"
 #include "simgrid/s4u/Link.hpp"
-#include "src/surf/surf_interface.hpp"
 #include "xbt/asserts.h"
 #include "xbt/ex.h"
 #include "xbt/mallocator.h"
@@ -18,11 +17,15 @@
 #include <cmath>
 #include <limits>
 #include <memory>
+#include <string_view>
 #include <vector>
 
-namespace simgrid {
-namespace kernel {
-namespace lmm {
+/* user-visible parameters */
+XBT_PUBLIC_DATA double sg_precision_workamount;
+XBT_PUBLIC_DATA double sg_precision_timing;
+XBT_PUBLIC_DATA int sg_concurrency_limit;
+
+namespace simgrid::kernel::lmm {
 
 /** @addtogroup SURF_lmm
  * @details
@@ -126,11 +129,12 @@ namespace lmm {
  *  - 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 */
@@ -150,7 +154,19 @@ public:
   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
@@ -194,7 +210,7 @@ public:
  */
 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);
 
@@ -208,7 +224,6 @@ public:
 
   /** @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)
@@ -236,6 +251,14 @@ public:
     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_;
@@ -319,12 +342,6 @@ public:
   /** @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
@@ -357,7 +374,7 @@ public:
   /** @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_;
@@ -371,11 +388,10 @@ public:
   //   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() */
@@ -407,7 +423,7 @@ public:
    * @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);
 
@@ -453,8 +469,11 @@ public:
    * @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);
+  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);
@@ -573,7 +592,7 @@ public:
       saturated_constraint_set;
 
 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;
@@ -592,8 +611,6 @@ private:
 };
 
 /** @} */
-} // namespace lmm
-} // namespace kernel
-} // namespace simgrid
+} // namespace simgrid::kernel::lmm
 
-#endif
\ No newline at end of file
+#endif