X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/fe503dfa41c532a17a4fc3f6b244e72e7783d386..f734ec7475682eb90323e804cbcfddd7e4523992:/src/include/surf/maxmin.h diff --git a/src/include/surf/maxmin.h b/src/include/surf/maxmin.h deleted file mode 100644 index df7571f3dc..0000000000 --- a/src/include/surf/maxmin.h +++ /dev/null @@ -1,464 +0,0 @@ -/* Copyright (c) 2004-2017. 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. */ - -#ifndef SURF_MAXMIN_H -#define SURF_MAXMIN_H - -#include "src/internal_config.h" -#include "xbt/misc.h" -#include "xbt/asserts.h" -#include "surf/datatypes.h" -#include - -namespace simgrid { -namespace surf { -class Action; -} -} - -/** @addtogroup SURF_lmm - * @details - * A linear maxmin solver to resolve inequations systems. - * - * Most SimGrid model rely on a "fluid/steady-state" modeling that simulate the sharing of resources between actions at - * relatively coarse-grain. Such sharing is generally done by solving a set of linear inequations. Let's take an - * example and assume we have the variables \f$x_1\f$, \f$x_2\f$, \f$x_3\f$, and \f$x_4\f$ . Let's say that \f$x_1\f$ - * and \f$x_2\f$ correspond to activities running and the same CPU \f$A\f$ whose capacity is \f$C_A\f$. In such a - * case, we need to enforce: - * - * \f[ x_1 + x_2 \leq C_A \f] - * - * Likewise, if \f$x_3\f$ (resp. \f$x_4\f$) corresponds to a network flow \f$F_3\f$ (resp. \f$F_4\f$) that goes through - * a set of links \f$L_1\f$ and \f$L_2\f$ (resp. \f$L_2\f$ and \f$L_3\f$), then we need to enforce: - * - * \f[ x_3 \leq C_{L_1} \f] - * \f[ x_3 + x_4 \leq C_{L_2} \f] - * \f[ x_4 \leq C_{L_3} \f] - * - * One could set every variable to 0 to make sure the constraints are satisfied but this would obviously not be very - * realistic. A possible objective is to try to maximize the minimum of the \f$x_i\f$ . This ensures that all the - * \f$x_i\f$ are positive and "as large as possible". - * - * This is called *max-min fairness* and is the most commonly used objective in SimGrid. Another possibility is to - * maximize \f$\sum_if(x_i)\f$, where \f$f\f$ is a strictly increasing concave function. - * - * 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 replaced by a max. - * For example, a third non-shared constraint `cons3` and the associated elements `elem5` and `elem6` could write as: - * - * max( var1.weight * var1.value * elem5.value , var3.weight * var3.value * elem6.value ) <= cons3.bound - * - * This is usefull for the sharing of resources for various models. - * For instance, for the network model, each link is associated to a constraint and each communication to a variable. - * - * Implementation details - * - * For implementation reasons, we are interested in distinguishing variables that actually participate to the - * computation of constraints, and those who are part of the equations but are stuck to zero. - * We call enabled variables, those which var.weight is strictly positive. Zero-weight variables are called disabled - * variables. - * Unfortunately this concept of enabled/disabled variables intersects with active/inactive variable. - * Semantically, the intent is similar, but the conditions under which a variable is active is slightly more strict - * than the conditions for it to be enabled. - * A variable is active only if its var.value is non-zero (and, by construction, its var.weight is non-zero). - * In general, variables remain disabled after their creation, which often models an initialization phase (e.g. first - * packet propagating in the network). Then, it is enabled by the corresponding model. Afterwards, the max-min solver - * (lmm_solve()) activates it when appropriate. It is possible that the variable is again disabled, e.g. to model the - * pausing of an action. - * - * Concurrency limit and maximum - * - * We call concurrency, the number of variables that can be enabled at any time for each constraint. - * From a model perspective, this "concurrency" often represents the number of actions that actually compete for one - * constraint. - * The LMM solver is able to limit the concurrency for each constraint, and to monitor its maximum value. - * - * One may want to limit the concurrency of constraints for essentially three reasons: - * - Keep LMM system in a size that can be solved (it does not react very well with tens of thousands of variables per - * constraint) - * - Stay within parameters where the fluid model is accurate enough. - * - Model serialization effects - * - * The concurrency limit can also be set to a negative value to disable concurrency limit. This can improve performance - * slightly. - * - * Overall, each constraint contains three fields related to concurrency: - * - concurrency_limit which is the limit enforced by the solver - * - 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. - */ - -XBT_PUBLIC_DATA(double) sg_maxmin_precision; -XBT_PUBLIC_DATA(double) sg_surf_precision; -XBT_PUBLIC_DATA(int) sg_concurrency_limit; - -static inline void double_update(double *variable, double value, double precision) -{ - //printf("Updating %g -= %g +- %g\n",*variable,value,precision); - //xbt_assert(value==0 || value>precision); - //Check that precision is higher than the machine-dependent size of the mantissa. If not, brutal rounding may happen, - //and the precision mechanism is not active... - //xbt_assert(*variable< (2< precision); -} - -static inline int double_equals(double value1, double value2, double precision) -{ - return (fabs(value1 - value2) < precision); -} - -SG_BEGIN_DECL() - -/** @{ @ingroup SURF_lmm */ -/** - * @brief Create a new Linear MaxMim system - * @param selective_update whether we should do lazy updates - */ -XBT_PUBLIC(lmm_system_t) lmm_system_new(bool 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); - -/** - * @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); - -/** - * @brief Share a constraint - * @param cnst The constraint to share - */ -XBT_PUBLIC(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 - */ -XBT_PUBLIC(int) lmm_constraint_sharing_policy(lmm_constraint_t cnst); - -/** - * @brief Free a constraint - * @param sys The system associated to the constraint - * @param cnst The constraint to free - */ -XBT_PUBLIC(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 - */ -XBT_PUBLIC(double) lmm_constraint_get_usage(lmm_constraint_t cnst); - -XBT_PUBLIC(int) lmm_constraint_get_variable_amount(lmm_constraint_t cnst); - -/** - * @brief Sets the concurrency limit for this constraint - * @param cnst A constraint - * @param concurrency_limit The concurrency limit to use for this constraint - */ -XBT_PUBLIC(void) lmm_constraint_concurrency_limit_set(lmm_constraint_t cnst, int concurrency_limit); - -/** - * @brief Gets the concurrency limit for this constraint - * @param cnst A constraint - * @return The concurrency limit used by this constraint - */ -XBT_PUBLIC(int) lmm_constraint_concurrency_limit_get(lmm_constraint_t cnst); - -/** - * @brief Reset the concurrency maximum for a given variable (we will update the maximum to reflect constraint - * evolution). - * @param cnst A constraint -*/ -XBT_PUBLIC(void) lmm_constraint_concurrency_maximum_reset(lmm_constraint_t cnst); - -/** - * @brief Get the concurrency maximum for a given variable (which reflects constraint evolution). - * @param cnst A constraint - * @return the maximum concurrency of the constraint - */ -XBT_PUBLIC(int) lmm_constraint_concurrency_maximum_get(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, simgrid::surf::Action* id, double weight_value, double bound, - int number_of_constraints); -/** - * @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 Set the concurrent share of the variable - * @param var A variable - * @param concurrency_share The new concurrency share - */ -XBT_PUBLIC(void) lmm_variable_concurrency_share_set(lmm_variable_t var, short int concurrency_share); - -/** - * @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); - -/** - * @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 - */ -XBT_PUBLIC(void) lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst, lmm_variable_t var, double value); - -/** - * @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 - */ -XBT_PUBLIC(lmm_constraint_t) lmm_get_cnst_from_var(lmm_system_t sys, lmm_variable_t var, int num); - -/** - * @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 - */ -XBT_PUBLIC(double) lmm_get_cnst_weight_from_var(lmm_system_t sys, lmm_variable_t var, int num); - -/** - * @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 - */ -XBT_PUBLIC(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 - */ -XBT_PUBLIC(lmm_variable_t) lmm_get_var_from_cnst(lmm_system_t sys, lmm_constraint_t cnst, lmm_element_t * elem); - -/** - * @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 cnst A constraint - * @param elem A element of constraint of the constraint or NULL - * @param nextelem A element of constraint of the constraint or NULL, the one after elem - * @param numelem parameter representing the number of elements to go - * - * @return A variable associated to a constraint - */ -XBT_PUBLIC(lmm_variable_t) lmm_get_var_from_cnst_safe(lmm_system_t sys, lmm_constraint_t cnst, - lmm_element_t * elem, lmm_element_t * nextelem, int * numelem); - -/** - * @brief Get the first active constraint of a system - * @param sys A system - * @return The first active constraint - */ -XBT_PUBLIC(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 - */ -XBT_PUBLIC(lmm_constraint_t) lmm_get_next_active_constraint(lmm_system_t sys, lmm_constraint_t cnst); - -/** - * @brief Get the data associated to a constraint - * @param cnst A constraint - * @return The data associated to the constraint - */ -XBT_PUBLIC(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 - */ -XBT_PUBLIC(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 - */ -XBT_PUBLIC(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 - */ -XBT_PUBLIC(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); - -/** - * @brief Get the weight of a variable - * @param var A variable - * @return The weight of the variable - */ -XBT_PUBLIC(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); - -/** - * @brief [brief description] - * @param sys A system - * @param cnst A constraint - * @return [description] - */ -XBT_PUBLIC(int) lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst); - -/** - * @brief Print the lmm system - * @param sys The lmm system to print - */ -XBT_PUBLIC(void) lmm_print(lmm_system_t sys); - -/** - * @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) bottleneck_solve(lmm_system_t sys); - -/** Default functions associated to the chosen protocol. When using the lagrangian approach. */ - -XBT_PUBLIC(void) lmm_set_default_protocol_function(double (*func_f)(lmm_variable_t var,double x), - double (*func_fp)(lmm_variable_t var,double x), - double (*func_fpi)(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_reno_fpi) (lmm_variable_t var, double x); - -XBT_PUBLIC(double func_reno2_f) (lmm_variable_t var, double x); -XBT_PUBLIC(double func_reno2_fp) (lmm_variable_t var, double x); -XBT_PUBLIC(double func_reno2_fpi) (lmm_variable_t var, double x); - -XBT_PUBLIC(double func_vegas_f) (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