X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/fc0a76c21f0bceb0314aee5d62f785ea8009495e..2c1cf331f7be1c55098faf7ba7a542149576614c:/src/include/surf/maxmin.h

diff --git a/src/include/surf/maxmin.h b/src/include/surf/maxmin.h
index 7f58d7c906..18dcef51c5 100644
--- a/src/include/surf/maxmin.h
+++ b/src/include/surf/maxmin.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2004-2014. The SimGrid Team.
+/* Copyright (c) 2004-2015. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -7,23 +7,24 @@
 #ifndef _SURF_MAXMIN_H
 #define _SURF_MAXMIN_H
 
-#include "portable.h"
+#include "src/portable.h"
 #include "xbt/misc.h"
+#include "xbt/asserts.h"
 #include "surf/datatypes.h"
 #include <math.h>
 
 
 /** @addtogroup SURF_lmm 
  * @details 
- * A linear maxmin solver to resolves inequations systems.
+ * A linear maxmin solver to resolve inequations systems.
  * 
  * Most SimGrid model rely on a "fluid/steady-state" modeling that
- * samount to share resources between actions at relatively
+ * 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
+ * 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]
@@ -52,10 +53,12 @@
  *  - bound (set)
  *  - shared (set)
  *  - usage (computed)
+ *
  * Variable:
  *  - weight (set)
  *  - bound (set)
  *  - value (computed)
+ *
  * Element:
  *  - value (set)
  * 
@@ -76,20 +79,28 @@
  *     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
+ * 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
+ * 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. 
  * 
- * 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.
  */
 
-extern double sg_maxmin_precision;
-extern double sg_surf_precision;
-
+XBT_PUBLIC_DATA(double) sg_maxmin_precision;
+XBT_PUBLIC_DATA(double) sg_surf_precision;
+ 
 static XBT_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<<DBL_MANT_DIG)*precision && FLT_RADIX==2);
   *variable -= value;
   if (*variable < precision)
     *variable = 0.0;
@@ -146,7 +157,7 @@ XBT_PUBLIC(void) lmm_constraint_shared(lmm_constraint_t cnst);
  * @param cnst The constraint to share
  * @return 1 if shared, 0 otherwise
  */
-XBT_PUBLIC(int) lmm_constraint_is_shared(lmm_constraint_t cnst);
+XBT_PUBLIC(int) lmm_constraint_sharing_policy(lmm_constraint_t cnst);
 
 /**
  * @brief Free a constraint
@@ -278,6 +289,23 @@ 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
  *