-/* $Id$ */
-
-/* Copyright (c) 2004 Arnaud Legrand. All rights reserved. */
+/* Copyright (c) 2004-2014. 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 "portable.h"
#include "xbt/misc.h"
#include "surf/datatypes.h"
+#include <math.h>
+
+
+/** @addtogroup SURF_lmm
+ * @details
+ * A linear maxmin solver to resolves inequations systems.
+ *
+ * A system is composed of variables, constraints and elements linking them.
+ * Constraint:
+ * - bound (set)
+ * - shared (set)
+ * - usage (computed)
+ * Variable:
+ * - weight (set)
+ * - bound (set)
+ * - value (computed)
+ * Element:
+ * - value (set)
+ *
+ * A possible system could be:
+ * - three variables: `var1`, `var2`, `var3`
+ * - two constraints: `cons1`, `cons2`
+ * - four elements linking:
+ * - `elem1` linking `var1` and `cons1`
+ * - `elem2` linking `var2` and `cons1`
+ * - `elem3` linking `var2` and `cons2`
+ * - `elem4` linking `var3` and `cons2`
+ *
+ * And the corresponding inequations will be:
+ *
+ * var1.value <= var1.bound
+ * var2.value <= var2.bound
+ * var3.value <= var3.bound
+ * var1.weight * var1.value * elem1.value + var2.weight * var2.value * elem2.value <= cons1.bound
+ * var2.weight * var2.value * elem3.value + var3.weight * var3.value * elem4.value <= cons2.bound
+ *
+ * where `var1.value`, `var2.value` and `var3.value` are the unknown values
+ *
+ * if a constraint is not shared the sum is replace by a max
+ *
+ * Its usefull for the sharing of resources for various models.
+ * For instance for the network model the link are associated
+ * to consrtaint and the communications to variables.
+ */
-#define MAXMIN_PRECISION 0.00001
+extern double sg_maxmin_precision;
+#define MAXMIN_PRECISION sg_maxmin_precision
static XBT_INLINE void double_update(double *variable, double value)
{
*variable -= value;
return (value > MAXMIN_PRECISION);
}
-XBT_PUBLIC(lmm_system_t) lmm_system_new(void);
+static XBT_INLINE int double_equals(double value1, double value2)
+{
+ return (fabs(value1 - value2) < MAXMIN_PRECISION);
+}
+
+SG_BEGIN_DECL()
+
+/** @{ @ingroup SURF_lmm */
+/**
+ * @brief Create a new Linear MaxMim system
+ *
+ * @param selective_update [description]
+ */
+XBT_PUBLIC(lmm_system_t) lmm_system_new(int selective_update);
+
+/**
+ * @brief Free an existing Linear MaxMin system
+ *
+ * @param sys The lmm system to free
+ */
XBT_PUBLIC(void) lmm_system_free(lmm_system_t sys);
- void lmm_variable_disable(lmm_system_t sys, lmm_variable_t var);
+/**
+ * @brief Create a new Linear MaxMin constraint
+ *
+ * @param sys The system in which we add a constraint
+ * @param id Data associated to the constraint (e.g.: a network link)
+ * @param bound_value The bound value of the constraint
+ */
XBT_PUBLIC(lmm_constraint_t) lmm_constraint_new(lmm_system_t sys, void *id,
double bound_value);
- void lmm_constraint_shared(lmm_constraint_t cnst);
- int lmm_constraint_is_shared(lmm_constraint_t cnst);
- void lmm_constraint_free(lmm_system_t sys, lmm_constraint_t cnst);
+/**
+ * @brief Share a constraint
+ * @details [long description]
+ *
+ * @param cnst The constraint to share
+ */
+void lmm_constraint_shared(lmm_constraint_t cnst);
+
+/**
+ * @brief Check if a constraint is shared (shared by default)
+ *
+ * @param cnst The constraint to share
+ * @return 1 if shared, 0 otherwise
+ */
+int lmm_constraint_is_shared(lmm_constraint_t cnst);
+/**
+ * @brief Free a constraint
+ *
+ * @param sys The system associated to the constraint
+ * @param cnst The constraint to free
+ */
+void lmm_constraint_free(lmm_system_t sys, lmm_constraint_t cnst);
+
+/**
+ * @brief Get the usage of the constraint after the last lmm solve
+ *
+ * @param cnst A constraint
+ * @return The usage of the constraint
+ */
+double lmm_constraint_get_usage(lmm_constraint_t cnst);
+
+/**
+ * @brief Create a new Linear MaxMin variable
+ *
+ * @param sys The system in which we add a constaint
+ * @param id Data associated to the variable (e.g.: a network communication)
+ * @param weight_value The weight of the variable (0.0 if not used)
+ * @param bound The maximum value of the variable (-1.0 if no maximum value)
+ * @param number_of_constraints The maximum number of constraint to associate to the variable
+ */
XBT_PUBLIC(lmm_variable_t) lmm_variable_new(lmm_system_t sys, void *id,
double weight_value,
double bound,
int number_of_constraints);
- void lmm_variable_free(lmm_system_t sys, lmm_variable_t var);
+/**
+ * @brief Free a variable
+ *
+ * @param sys The system associated to the variable
+ * @param var The variable to free
+ */
+XBT_PUBLIC(void) lmm_variable_free(lmm_system_t sys, lmm_variable_t var);
+
+/**
+ * @brief Get the value of the variable after the last lmm solve
+ *
+ * @param var A variable
+ * @return The value of the variable
+ */
XBT_PUBLIC(double) lmm_variable_getvalue(lmm_variable_t var);
+
+/**
+ * @brief Get the maximum value of the variable (-1.0 if no maximum value)
+ *
+ * @param var A variable
+ * @return The bound of the variable
+ */
XBT_PUBLIC(double) lmm_variable_getbound(lmm_variable_t var);
+/**
+ * @brief Remove a variable from a constraint
+ *
+ * @param sys A system
+ * @param cnst A constraint
+ * @param var The variable to remove
+ */
+XBT_PUBLIC(void) lmm_shrink(lmm_system_t sys, lmm_constraint_t cnst,
+ lmm_variable_t var);
+
+/**
+ * @brief Associate a variable to a constraint with a coefficient
+ *
+ * @param sys A system
+ * @param cnst A constraint
+ * @param var A variable
+ * @param value The coefficient associated to the variable in the constraint
+ */
XBT_PUBLIC(void) lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
lmm_variable_t var, double value);
- void lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst,
- lmm_variable_t var, double value);
- void lmm_elem_set_value(lmm_system_t sys, lmm_constraint_t cnst,
- lmm_variable_t var, double value);
- lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t sys,
- lmm_variable_t var, int num);
- int lmm_get_number_of_cnst_from_var(lmm_system_t sys,
- lmm_variable_t var);
- lmm_variable_t lmm_get_var_from_cnst(lmm_system_t sys,
- lmm_constraint_t cnst,
- lmm_element_t * elem);
+/**
+ * @brief Add value to the coefficient between a constraint and a variable or
+ * create one
+ *
+ * @param sys A system
+ * @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 lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst,
+ lmm_variable_t var, double value);
- lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t sys);
- lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t sys,
- lmm_constraint_t cnst);
+/**
+ * @brief Get the numth constraint associated to the variable
+ *
+ * @param sys The system associated to the variable (not used)
+ * @param var A variable
+ * @param num The rank of constraint we want to get
+ * @return The numth constraint
+ */
+lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t sys,
+ lmm_variable_t var, int num);
- void *lmm_constraint_id(lmm_constraint_t cnst);
- void *lmm_variable_id(lmm_variable_t var);
+/**
+ * @brief Get the weigth of the numth constraint associated to the variable
+ *
+ * @param sys The system associated to the variable (not used)
+ * @param var A variable
+ * @param num The rank of constraint we want to get
+ * @return The numth constraint
+ */
+double lmm_get_cnst_weight_from_var(lmm_system_t sys, lmm_variable_t var,
+ int num);
- void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
- lmm_variable_t var, double value);
- void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var,
- double bound);
+/**
+ * @brief Get the number of constraint associated to a variable
+ *
+ * @param sys The system associated to the variable (not used)
+ * @param var A variable
+ * @return The number of constraint associated to the variable
+ */
+int lmm_get_number_of_cnst_from_var(lmm_system_t sys, lmm_variable_t var);
+/**
+ * @brief Get a var associated to a constraint
+ * @details Get the first variable of the next variable of elem if elem is not NULL
+ *
+ * @param sys The system associated to the variable (not used)
+ * @param cnst A constraint
+ * @param elem A element of constraint of the constraint or NULL
+ * @return A variable associated to a constraint
+ */
+lmm_variable_t lmm_get_var_from_cnst(lmm_system_t sys,
+ lmm_constraint_t cnst,
+ lmm_element_t * elem);
+/**
+ * @brief Get the first active constraint of a system
+ *
+ * @param sys A system
+ * @return The first active constraint
+ */
+lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t sys);
+
+/**
+ * @brief Get the next active constraint of a constraint in a system
+ *
+ * @param sys A system
+ * @param cnst An active constraint of the system
+ *
+ * @return The next active constraint
+ */
+lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t sys,
+ lmm_constraint_t cnst);
+
+#ifdef HAVE_LATENCY_BOUND_TRACKING
+XBT_PUBLIC(int) lmm_is_variable_limited_by_latency(lmm_variable_t var);
+#endif
+
+/**
+ * @brief Get the data associated to a constraint
+ *
+ * @param cnst A constraint
+ * @return The data associated to the constraint
+ */
+void *lmm_constraint_id(lmm_constraint_t cnst);
+
+/**
+ * @brief Get the data associated to a variable
+ *
+ * @param var A variable
+ * @return The data associated to the variable
+ */
+void *lmm_variable_id(lmm_variable_t var);
+
+/**
+ * @brief Update the value of element linking the constraint and the variable
+ *
+ * @param sys A system
+ * @param cnst A constraint
+ * @param var A variable
+ * @param value The new value
+ */
+void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
+ lmm_variable_t var, double value);
+
+/**
+ * @brief Update the bound of a variable
+ *
+ * @param sys A system
+ * @param var A constraint
+ * @param bound The new bound
+ */
+void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var,
+ double bound);
+
+/**
+ * @brief Update the weight of a variable
+ *
+ * @param sys A system
+ * @param var A variable
+ * @param weight The new weight of the variable
+ */
XBT_PUBLIC(void) lmm_update_variable_weight(lmm_system_t sys,
lmm_variable_t var,
double weight);
- double lmm_get_variable_weight(lmm_variable_t var);
+/**
+ * @brief Get the weight of a variable
+ *
+ * @param var A variable
+ * @return The weight of the variable
+ */
+double lmm_get_variable_weight(lmm_variable_t var);
+
+/**
+ * @brief Update a constraint bound
+ *
+ * @param sys A system
+ * @param cnst A constraint
+ * @param bound The new bound of the consrtaint
+ */
XBT_PUBLIC(void) lmm_update_constraint_bound(lmm_system_t sys,
lmm_constraint_t cnst,
double bound);
- int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst);
-
+/**
+ * @brief [brief description]
+ *
+ * @param sys A system
+ * @param cnst A constraint
+ * @return [description]
+ */
+int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst);
+/**
+ * @brief Solve the lmm system
+ *
+ * @param sys The lmm system to solve
+ */
XBT_PUBLIC(void) lmm_solve(lmm_system_t sys);
XBT_PUBLIC(void) lagrange_solve(lmm_system_t sys);
*/
XBT_PUBLIC(void) lmm_set_default_protocol_function(double (*func_f)
- (lmm_variable_t var, double x),
+ (lmm_variable_t var,
+ double x),
double (*func_fp)
- (lmm_variable_t var, double x),
+ (lmm_variable_t var,
+ double x),
double (*func_fpi)
- (lmm_variable_t var, double x));
+ (lmm_variable_t var,
+ double x));
XBT_PUBLIC(double func_reno_f) (lmm_variable_t var, double x);
XBT_PUBLIC(double func_reno_fp) (lmm_variable_t var, double x);
XBT_PUBLIC(double func_vegas_fp) (lmm_variable_t var, double x);
XBT_PUBLIC(double func_vegas_fpi) (lmm_variable_t var, double x);
+/** @} */
+SG_END_DECL()
-#endif /* _SURF_MAXMIN_H */
+#endif /* _SURF_MAXMIN_H */
