[simgrid.git] / src / instr / instr_interface.c

/* Copyright (c) 2010. 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 "simgrid_config.h"

#ifdef HAVE_TRACING
#include "instr/instr_private.h"
#include "surf/network_private.h"

typedef enum {
  INSTR_US_DECLARE,
  INSTR_US_SET,
  INSTR_US_ADD,
  INSTR_US_SUB
} InstrUserVariable;

XBT_LOG_NEW_DEFAULT_SUBCATEGORY (instr_api, instr, "API");

xbt_dict_t created_categories = NULL;
xbt_dict_t declared_marks = NULL;
xbt_dict_t user_host_variables = NULL;
xbt_dict_t user_link_variables = NULL;

static xbt_dynar_t instr_dict_to_dynar (xbt_dict_t filter)
{
  if (!TRACE_is_enabled()) return NULL;
  if (!TRACE_needs_platform()) return NULL;

  xbt_dynar_t ret = xbt_dynar_new (sizeof(char*), &xbt_free_ref);
  xbt_dict_cursor_t cursor = NULL;
  char *name, *value;
  xbt_dict_foreach(filter, cursor, name, value) {
    xbt_dynar_push_as (ret, char*, xbt_strdup(name));
  }
  return ret;
}

/** \ingroup TRACE_category
 *  \brief Declare a new category with a random color.
 *
 *  This function should be used to define a user category. The
 *  category can be used to differentiate the tasks that are created
 *  during the simulation (for example, tasks from server1, server2,
 *  or request tasks, computation tasks, communication tasks). All
 *  resource utilization (host power and link bandwidth) will be
 *  classified according to the task category. Tasks that do not
 *  belong to a category are not traced. The color for the category
 *  that is being declared is random. This function has no effect
 *  if a category with the same name has been already declared.
 *
 * See \ref tracing_tracing for details on how to trace
 * the (categorized) resource utilization.
 *
 *  \param category The name of the new tracing category to be created.
 *
 *  \see TRACE_category_with_color, MSG_task_set_category, SD_task_set_category
 */
void TRACE_category(const char *category)
{
  TRACE_category_with_color (category, NULL);
}

/** \ingroup TRACE_category
 *  \brief Declare a new category with a color.
 *
 *  Same as #TRACE_category, but let user specify a color encoded as a
 *  RGB-like string with three floats from 0 to 1. So, to specify a
 *  red color, pass "1 0 0" as color parameter. A light-gray color
 *  can be specified using "0.7 0.7 0.7" as color. This function has
 *  no effect if a category with the same name has been already declared.
 *
 * See \ref tracing_tracing for details on how to trace
 * the (categorized) resource utilization.
 *
 *  \param category The name of the new tracing category to be created.
 *  \param color The color of the category (see \ref tracing_tracing to
 *  know how to correctly specify the color)
 *
 *  \see MSG_task_set_category, SD_task_set_category
 */
void TRACE_category_with_color (const char *category, const char *color)
{
  /* safe switch */
  if (!TRACE_is_enabled()) return;

  if (!(TRACE_categorized() && category != NULL)) return;

  /* if platform is not traced, we can't deal with categories */
  if (!TRACE_needs_platform()) return;

  //check if category is already created
  char *created = xbt_dict_get_or_null(created_categories, category);
  if (created) return;
  xbt_dict_set (created_categories, category, xbt_strdup("1"), NULL);

  //define final_color
  char final_color[INSTR_DEFAULT_STR_SIZE];
  if (!color){
    //generate a random color
    double red = drand48();
    double green = drand48();
    double blue = drand48();
    snprintf (final_color, INSTR_DEFAULT_STR_SIZE, "%f %f %f", red, green, blue);
  }else{
    snprintf (final_color, INSTR_DEFAULT_STR_SIZE, "%s", color);
  }

  XBT_DEBUG("CAT,declare %s, %s", category, final_color);

  //define the type of this category on top of hosts and links
  instr_new_variable_type (category, final_color);
}


/** \ingroup TRACE_category
 *  \brief Get declared categories
 *
 * This function should be used to get categories that were already
 * declared with #TRACE_category or with #TRACE_category_with_color.
 *
 * See \ref tracing_tracing for details on how to trace
 * the (categorized) resource utilization.
 *
 * \return A dynar with the declared categories, must be freed with xbt_dynar_free.
 *
 *  \see MSG_task_set_category, SD_task_set_category
 */
xbt_dynar_t TRACE_get_categories (void)
{
  if (!TRACE_is_enabled()) return NULL;
  if (!TRACE_categorized()) return NULL;

  return instr_dict_to_dynar (created_categories);
}

/** \ingroup TRACE_mark
 * \brief Declare a new type for tracing mark.
 *
 * This function declares a new Paje event
 * type in the trace file that can be used by
 * simulators to declare application-level
 * marks. This function is independent of
 * which API is used in SimGrid.
 *
 * \param mark_type The name of the new type.
 *
 * \see TRACE_mark
 */
void TRACE_declare_mark(const char *mark_type)
{
  /* safe switch */
  if (!TRACE_is_enabled()) return;

  if (!mark_type) return;

  //check if mark_type is already declared
  char *created = xbt_dict_get_or_null(declared_marks, mark_type);
  if (created) return;
  xbt_dict_set (declared_marks, mark_type, xbt_strdup("1"), NULL);

  XBT_DEBUG("MARK,declare %s", mark_type);
  PJ_type_event_new(mark_type, NULL, PJ_type_get_root());
}

/**
 * \ingroup TRACE_mark
 * \brief Create a new instance of a tracing mark type.
 *
 * This function creates a mark in the trace file. The
 * first parameter had to be previously declared using
 * #TRACE_declare_mark, the second is the identifier
 * for this mark instance. We recommend that the
 * mark_value is a unique value for the whole simulation.
 * Nevertheless, this is not a strong requirement: the
 * trace will be valid even if there are multiple mark
 * identifiers for the same trace.
 *
 * \param mark_type The name of the type for which the new instance will belong.
 * \param mark_value The name of the new instance mark.
 *
 * \see TRACE_declare_mark
 */
void TRACE_mark(const char *mark_type, const char *mark_value)
{
  /* safe switch */
  if (!TRACE_is_enabled()) return;

  if (!mark_type || !mark_value) return;

  //check if mark_type is already declared
  char *created = xbt_dict_get_or_null(declared_marks, mark_type);
  if (created) return;

  XBT_DEBUG("MARK %s %s", mark_type, mark_value);
  type_t type = PJ_type_get (mark_type, PJ_type_get_root());
  if (type == NULL){
    THROWF (tracing_error, 1, "mark_type with name (%s) not declared before", mark_type);
  }
  val_t value = PJ_value_get (mark_value, type);
  if (value == NULL){
    value = PJ_value_new (mark_value, NULL, type);
  }
  new_pajeNewEvent (MSG_get_clock(), PJ_container_get_root(), type, value);
}

/** \ingroup TRACE_mark
 *  \brief Get declared marks
 *
 * This function should be used to get marks that were already
 * declared with #TRACE_declare_mark.
 *
 * \return A dynar with the declared marks, must be freed with xbt_dynar_free.
 *
 */
xbt_dynar_t TRACE_get_marks (void)
{
  if (!TRACE_is_enabled()) return NULL;

  return instr_dict_to_dynar (declared_marks);
}

static void instr_user_variable(double time,
                         const char *resource,
                         const char *variable,
                         const char *father_type,
                         double value,
                         InstrUserVariable what,
                         const char *color,
                         xbt_dict_t filter)
{
  /* safe switch */
  if (!TRACE_is_enabled()) return;

  /* if platform is not traced, we don't allow user variables */
  if (!TRACE_needs_platform()) return;

  //check if variable is already declared
  char *created = xbt_dict_get_or_null(declared_marks, variable);
  if (what == INSTR_US_DECLARE){
    if (created){
      //already declared
      return;
    }else{
      xbt_dict_set (filter, variable, xbt_strdup("1"), NULL);
    }
  }else{
    if (!created){
      //not declared, ignore
      return;
    }
  }

  char valuestr[100];
  snprintf(valuestr, 100, "%g", value);

  switch (what){
  case INSTR_US_DECLARE:
    instr_new_user_variable_type (father_type, variable, color);
    break;
  case INSTR_US_SET:
  {
    container_t container = PJ_container_get(resource);
    type_t type = PJ_type_get (variable, container->type);
    new_pajeSetVariable(time, container, type, value);
    break;
  }
  case INSTR_US_ADD:
  {
    container_t container = PJ_container_get(resource);
    type_t type = PJ_type_get (variable, container->type);
    new_pajeAddVariable(time, container, type, value);
    break;
  }
  case INSTR_US_SUB:
  {
    container_t container = PJ_container_get(resource);
    type_t type = PJ_type_get (variable, container->type);
    new_pajeSubVariable(time, container, type, value);
    break;
  }
  default:
    //TODO: launch exception
    break;
  }
}

static void instr_user_srcdst_variable(double time,
                              const char *src,
                              const char *dst,
                              const char *variable,
                              const char *father_type,
                              double value,
                              InstrUserVariable what)
{
  xbt_dynar_t route=NULL;
  network_element_t src_elm = xbt_lib_get_or_null(host_lib,src,ROUTING_HOST_LEVEL);
  if(!src_elm) src_elm = xbt_lib_get_or_null(as_router_lib,src,ROUTING_ASR_LEVEL);
  if(!src_elm) xbt_die("Element '%s' not found!",src);

  network_element_t dst_elm = xbt_lib_get_or_null(host_lib,dst,ROUTING_HOST_LEVEL);
  if(!dst_elm) dst_elm = xbt_lib_get_or_null(as_router_lib,dst,ROUTING_ASR_LEVEL);
  if(!dst_elm) xbt_die("Element '%s' not found!",dst);

  routing_get_route_and_latency (src_elm, dst_elm, &route,NULL);
  unsigned int i;
  void *link;
  xbt_dynar_foreach (route, i, link) {
    char *link_name = ((link_CM02_t)link)->lmm_resource.generic_resource.name;
    instr_user_variable (time, link_name, variable, father_type, value, what, NULL, user_link_variables);
  }
}

/** \ingroup TRACE_API
 *  \brief Creates a file with the topology of the platform file used for the simulator.
 *
 *  The graph topology will have the following properties: all hosts, links and routers
 *  of the platform file are mapped to graph nodes; routes are mapped to edges.
 *  The platform's AS are not represented in the output.
 *
 *  \param filename The name of the file that will hold the graph.
 *
 *  \return 1 of successful, 0 otherwise.
 */
int TRACE_platform_graph_export_graphviz (const char *filename)
{
  /* returns 1 if successful, 0 otherwise */
  if (!TRACE_is_enabled()) return 0;
  xbt_graph_t g = instr_routing_platform_graph();
  if (g == NULL) return 0;
  instr_routing_platform_graph_export_graphviz (g, filename);
  xbt_graph_free_graph (g, xbt_free, xbt_free, NULL);
  return 1;
}

/*
 * Derived functions that use instr_user_variable and TRACE_user_srcdst_variable.
 * They were previously defined as pre-processors directives, but were transformed
 * into functions so the user can track them using gdb.
 */

/* for host variables */
/** \ingroup TRACE_user_variables
 *  \brief Declare a new user variable associated to hosts.
 *
 *  Declare a user variable that will be associated to hosts.
 *  A user host variable can be used to trace user variables
 *  such as the number of tasks in a server, the number of
 *  clients in an application (for hosts), and so on. The color
 *  associated to this new variable will be random.
 *
 *  \param variable The name of the new variable to be declared.
 *
 *  \see TRACE_host_variable_declare_with_color
 */
void TRACE_host_variable_declare (const char *variable)
{
  instr_user_variable(0, NULL, variable, "HOST", 0, INSTR_US_DECLARE, NULL, user_host_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Declare a new user variable associated to hosts with a color.
 *
 *  Same as #TRACE_host_variable_declare, but associated a color
 *  to the newly created user host variable. The color needs to be
 *  a string with three numbers separated by spaces in the range [0,1].
 *  A light-gray color can be specified using "0.7 0.7 0.7" as color.
 *
 *  \param variable The name of the new variable to be declared.
 *  \param color The color for the new variable.
 *
 */
void TRACE_host_variable_declare_with_color (const char *variable, const char *color)
{
  instr_user_variable(0, NULL, variable, "HOST", 0, INSTR_US_DECLARE, color, user_host_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Set the value of a variable of a host.
 *
 *  \param host The name of the host to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The new value of the variable.
 *
 *  \see TRACE_host_variable_declare, TRACE_host_variable_add, TRACE_host_variable_sub
 */
void TRACE_host_variable_set (const char *host, const char *variable, double value)
{
  TRACE_host_variable_set_with_time (MSG_get_clock(), host, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Add a value to a variable of a host.
 *
 *  \param host The name of the host to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be added to the variable.
 *
 *  \see TRACE_host_variable_declare, TRACE_host_variable_set, TRACE_host_variable_sub
 */
void TRACE_host_variable_add (const char *host, const char *variable, double value)
{
  TRACE_host_variable_add_with_time (MSG_get_clock(), host, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Subtract a value from a variable of a host.
 *
 *  \param host The name of the host to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be subtracted from the variable.
 *
 *  \see TRACE_host_variable_declare, TRACE_host_variable_set, TRACE_host_variable_add
 */
void TRACE_host_variable_sub (const char *host, const char *variable, double value)
{
  TRACE_host_variable_sub_with_time (MSG_get_clock(), host, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Set the value of a variable of a host at a given timestamp.
 *
 *  Same as #TRACE_host_variable_set, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param host The name of the host to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The new value of the variable.
 *
 *  \see TRACE_host_variable_declare, TRACE_host_variable_add_with_time, TRACE_host_variable_sub_with_time
 */
void TRACE_host_variable_set_with_time (double time, const char *host, const char *variable, double value)
{
  instr_user_variable(time, host, variable, "HOST", value, INSTR_US_SET, NULL, user_host_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Add a value to a variable of a host at a given timestamp.
 *
 *  Same as #TRACE_host_variable_add, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param host The name of the host to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be added to the variable.
 *
 *  \see TRACE_host_variable_declare, TRACE_host_variable_set_with_time, TRACE_host_variable_sub_with_time
 */
void TRACE_host_variable_add_with_time (double time, const char *host, const char *variable, double value)
{
  instr_user_variable(time, host, variable, "HOST", value, INSTR_US_ADD, NULL, user_host_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Subtract a value from a variable of a host at a given timestamp.
 *
 *  Same as #TRACE_host_variable_sub, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param host The name of the host to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be subtracted from the variable.
 *
 *  \see TRACE_host_variable_declare, TRACE_host_variable_set_with_time, TRACE_host_variable_add_with_time
 */
void TRACE_host_variable_sub_with_time (double time, const char *host, const char *variable, double value)
{
  instr_user_variable(time, host, variable, "HOST", value, INSTR_US_SUB, NULL, user_host_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Get declared user host variables
 *
 * This function should be used to get host variables that were already
 * declared with #TRACE_host_variable_declare or with #TRACE_host_variable_declare_with_color.
 *
 * \return A dynar with the declared host variables, must be freed with xbt_dynar_free.
 */
xbt_dynar_t TRACE_get_host_variables (void)
{
  return instr_dict_to_dynar (user_host_variables);
}

/* for link variables */
/** \ingroup TRACE_user_variables
 *  \brief Declare a new user variable associated to links.
 *
 *  Declare a user variable that will be associated to links.
 *  A user link variable can be used, for example, to trace
 *  user variables such as the number of messages being
 *  transferred through network links. The color
 *  associated to this new variable will be random.
 *
 *  \param variable The name of the new variable to be declared.
 *
 *  \see TRACE_link_variable_declare_with_color
 */
void TRACE_link_variable_declare (const char *variable)
{
  instr_user_variable (0, NULL, variable, "LINK", 0, INSTR_US_DECLARE, NULL, user_link_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Declare a new user variable associated to links with a color.
 *
 *  Same as #TRACE_link_variable_declare, but associated a color
 *  to the newly created user link variable. The color needs to be
 *  a string with three numbers separated by spaces in the range [0,1].
 *  A light-gray color can be specified using "0.7 0.7 0.7" as color.
 *
 *  \param variable The name of the new variable to be declared.
 *  \param color The color for the new variable.
 *
 */
void TRACE_link_variable_declare_with_color (const char *variable, const char *color)
{
  instr_user_variable (0, NULL, variable, "LINK", 0, INSTR_US_DECLARE, color, user_link_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Set the value of a variable of a link.
 *
 *  \param link The name of the link to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The new value of the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_variable_add, TRACE_link_variable_sub
 */
void TRACE_link_variable_set (const char *link, const char *variable, double value)
{
  TRACE_link_variable_set_with_time (MSG_get_clock(), link, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Add a value to a variable of a link.
 *
 *  \param link The name of the link to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be added to the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_variable_set, TRACE_link_variable_sub
 */
void TRACE_link_variable_add (const char *link, const char *variable, double value)
{
  TRACE_link_variable_add_with_time (MSG_get_clock(), link, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Subtract a value from a variable of a link.
 *
 *  \param link The name of the link to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be subtracted from the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_variable_set, TRACE_link_variable_add
 */
void TRACE_link_variable_sub (const char *link, const char *variable, double value)
{
  TRACE_link_variable_sub_with_time (MSG_get_clock(), link, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Set the value of a variable of a link at a given timestamp.
 *
 *  Same as #TRACE_link_variable_set, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param link The name of the link to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The new value of the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_variable_add_with_time, TRACE_link_variable_sub_with_time
 */
void TRACE_link_variable_set_with_time (double time, const char *link, const char *variable, double value)
{
  instr_user_variable (time, link, variable, "LINK", value, INSTR_US_SET, NULL, user_link_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Add a value to a variable of a link at a given timestamp.
 *
 *  Same as #TRACE_link_variable_add, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param link The name of the link to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be added to the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_variable_set_with_time, TRACE_link_variable_sub_with_time
 */
void TRACE_link_variable_add_with_time (double time, const char *link, const char *variable, double value)
{
  instr_user_variable (time, link, variable, "LINK", value, INSTR_US_ADD, NULL, user_link_variables);
}

/** \ingroup TRACE_user_variables
 *  \brief Subtract a value from a variable of a link at a given timestamp.
 *
 *  Same as #TRACE_link_variable_sub, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param link The name of the link to be considered.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be subtracted from the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_variable_set_with_time, TRACE_link_variable_add_with_time
 */
void TRACE_link_variable_sub_with_time (double time, const char *link, const char *variable, double value)
{
  instr_user_variable (time, link, variable, "LINK", value, INSTR_US_SUB, NULL, user_link_variables);
}

/* for link variables, but with src and dst used for get_route */
/** \ingroup TRACE_user_variables
 *  \brief Set the value of the variable present in the links connecting source and destination.
 *
 *  Same as #TRACE_link_variable_set, but instead of providing the
 *  name of link to be considered, provide the source and destination
 *  hosts. All links that are part of the route between source and
 *  destination will have the variable set to the provided value.
 *
 *  \param src The name of the source host for get route.
 *  \param dst The name of the destination host for get route.
 *  \param variable The name of the variable to be considered.
 *  \param value The new value of the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_srcdst_variable_add, TRACE_link_srcdst_variable_sub
 */
void TRACE_link_srcdst_variable_set (const char *src, const char *dst, const char *variable, double value)
{
  TRACE_link_srcdst_variable_set_with_time (MSG_get_clock(), src, dst, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Add a value to the variable present in the links connecting source and destination.
 *
 *  Same as #TRACE_link_variable_add, but instead of providing the
 *  name of link to be considered, provide the source and destination
 *  hosts. All links that are part of the route between source and
 *  destination will have the value passed as parameter added to
 *  the current value of the variable name to be considered.
 *
 *  \param src The name of the source host for get route.
 *  \param dst The name of the destination host for get route.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be added to the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_srcdst_variable_set, TRACE_link_srcdst_variable_sub
 */
void TRACE_link_srcdst_variable_add (const char *src, const char *dst, const char *variable, double value)
{
  TRACE_link_srcdst_variable_add_with_time (MSG_get_clock(), src, dst, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Subtract a value from the variable present in the links connecting source and destination.
 *
 *  Same as #TRACE_link_variable_sub, but instead of providing the
 *  name of link to be considered, provide the source and destination
 *  hosts. All links that are part of the route between source and
 *  destination will have the value passed as parameter subtracted from
 *  the current value of the variable name to be considered.
 *
 *  \param src The name of the source host for get route.
 *  \param dst The name of the destination host for get route.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be subtracted from the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_srcdst_variable_set, TRACE_link_srcdst_variable_add
 */
void TRACE_link_srcdst_variable_sub (const char *src, const char *dst, const char *variable, double value)
{
  TRACE_link_srcdst_variable_sub_with_time (MSG_get_clock(), src, dst, variable, value);
}

/** \ingroup TRACE_user_variables
 *  \brief Set the value of the variable present in the links connecting source and destination at a given timestamp.
 *
 *  Same as #TRACE_link_srcdst_variable_set, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param src The name of the source host for get route.
 *  \param dst The name of the destination host for get route.
 *  \param variable The name of the variable to be considered.
 *  \param value The new value of the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_srcdst_variable_add_with_time, TRACE_link_srcdst_variable_sub_with_time
 */
void TRACE_link_srcdst_variable_set_with_time (double time, const char *src, const char *dst, const char *variable, double value)
{
  instr_user_srcdst_variable (time, src, dst, variable, "LINK", value, INSTR_US_SET);
}

/** \ingroup TRACE_user_variables
 *  \brief Add a value to the variable present in the links connecting source and destination at a given timestamp.
 *
 *  Same as #TRACE_link_srcdst_variable_add, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param src The name of the source host for get route.
 *  \param dst The name of the destination host for get route.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be added to the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_srcdst_variable_set_with_time, TRACE_link_srcdst_variable_sub_with_time
 */
void TRACE_link_srcdst_variable_add_with_time (double time, const char *src, const char *dst, const char *variable, double value)
{
  instr_user_srcdst_variable (time, src, dst, variable, "LINK", value, INSTR_US_ADD);
}

/** \ingroup TRACE_user_variables
 *  \brief Subtract a value from the variable present in the links connecting source and destination at a given timestamp.
 *
 *  Same as #TRACE_link_srcdst_variable_sub, but let user specify
 *  the time used to trace it. Users can specify a time that
 *  is not the simulated clock time as defined by the core
 *  simulator. This allows a fine-grain control of time
 *  definition, but should be used with caution since the trace
 *  can be inconsistent if resource utilization traces are also traced.
 *
 *  \param time The timestamp to be used to tag this change of value.
 *  \param src The name of the source host for get route.
 *  \param dst The name of the destination host for get route.
 *  \param variable The name of the variable to be considered.
 *  \param value The value to be subtracted from the variable.
 *
 *  \see TRACE_link_variable_declare, TRACE_link_srcdst_variable_set_with_time, TRACE_link_srcdst_variable_add_with_time
 */
void TRACE_link_srcdst_variable_sub_with_time (double time, const char *src, const char *dst, const char *variable, double value)
{
  instr_user_srcdst_variable (time, src, dst, variable, "LINK", value, INSTR_US_SUB);
}

/** \ingroup TRACE_user_variables
 *  \brief Get declared user link variables
 *
 * This function should be used to get link variables that were already
 * declared with #TRACE_link_variable_declare or with #TRACE_link_variable_declare_with_color.
 *
 * \return A dynar with the declared link variables, must be freed with xbt_dynar_free.
 */
xbt_dynar_t TRACE_get_link_variables (void)
{
  return instr_dict_to_dynar (user_link_variables);
}

#endif /* HAVE_TRACING */