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Don't auto-destroy the MSG_comm_t in MSG_comm_wait(), it's the
[simgrid.git] / src / msg / gos.c
index 8297d8f..899b135 100644 (file)
-/*     $Id$      */
-
-/* Copyright (c) 2002-2007 Arnaud Legrand.                                  */
-/* Copyright (c) 2007 Bruno Donassolo.                                      */
-/* All rights reserved.                                                     */
+/* Copyright (c) 2004, 2005, 2006, 2007, 2008, 2009, 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 "msg/private.h"
+#include "private.h"
 #include "xbt/sysdep.h"
+#include "mc/mc.h"
 #include "xbt/log.h"
-#include "msg_mailbox.h"
+#include "mailbox.h"
 
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_gos, msg,
-                               "Logging specific to MSG (gos)");
-
-/** \defgroup msg_gos_functions MSG Operating System Functions
- *  \brief This section describes the functions that can be used
- *  by an agent for handling some task.
- */
-
-MSG_error_t MSG_task_get_ext(m_task_t * task,
-                            m_channel_t channel,
-                            double max_duration,
-                            m_host_t host)
-{
-
-  m_process_t process = MSG_process_self();
-  m_task_t t = NULL;
-  m_host_t h = NULL;
-  simdata_task_t t_simdata = NULL;
-  simdata_host_t h_simdata = NULL;
-  int first_time = 1;
-  xbt_fifo_item_t item = NULL;
-
-  smx_cond_t cond = NULL;      //conditional wait if the task isn't on the channel yet
-
-  CHECK_HOST();
-  xbt_assert1((channel >= 0)
-             && (channel < msg_global->max_channel), "Invalid channel %d",
-             channel);
-  /* Sanity check */
-  xbt_assert0(task, "Null pointer for the task storage");
-
-  if (*task)
-    CRITICAL0
-       ("MSG_task_get() was asked to write in a non empty task struct.");
-
-  /* Get the task */
-  h = MSG_host_self();
-  h_simdata = h->simdata;
-
-  DEBUG2("Waiting for a task on channel %d (%s)", channel, h->name);
-
-  SIMIX_mutex_lock(h->simdata->mutex);
-  while (1) {
-    if (xbt_fifo_size(h_simdata->mbox[channel]) > 0) {
-      if (!host) {
-       t = xbt_fifo_shift(h_simdata->mbox[channel]);
-       break;
-      } else {
-       xbt_fifo_foreach(h->simdata->mbox[channel], item, t, m_task_t) {
-         if (t->simdata->source == host)
-           break;
-       }
-       if (item) {
-         xbt_fifo_remove_item(h->simdata->mbox[channel], item);
-         break;
-       }
-      }
-    }
-
-    if (max_duration > 0) {
-      if (!first_time) {
-       SIMIX_mutex_unlock(h->simdata->mutex);
-       h_simdata->sleeping[channel] = NULL;
-       SIMIX_cond_destroy(cond);
-       MSG_RETURN(MSG_TRANSFER_FAILURE);
-      }
-    }
-    xbt_assert1(!(h_simdata->sleeping[channel]),
-               "A process is already blocked on channel %d", channel);
-
-    cond = SIMIX_cond_init();
-    h_simdata->sleeping[channel] = cond;
-    if (max_duration > 0)
-      SIMIX_cond_wait_timeout(cond, h->simdata->mutex, max_duration);
-    else 
-      SIMIX_cond_wait(h_simdata->sleeping[channel], h->simdata->mutex);
-
-    if (SIMIX_host_get_state(h_simdata->smx_host) == 0)
-      MSG_RETURN(MSG_HOST_FAILURE);
-
-    first_time = 0;
-  }
-  SIMIX_mutex_unlock(h->simdata->mutex);
-
-  DEBUG1("OK, got a task (%s)", t->name);
-  /* clean conditional */
-  if (cond) {
-    SIMIX_cond_destroy(cond);
-    h_simdata->sleeping[channel] = NULL;
-  }
-
-  t_simdata = t->simdata;
-  t_simdata->receiver = process;
-  *task = t;
-
-  SIMIX_mutex_lock(t_simdata->mutex);
-
-  /* Transfer */
-  /* create SIMIX action to the communication */
-  t_simdata->comm =
-      SIMIX_action_communicate(t_simdata->sender->simdata->m_host->
-                              simdata->smx_host,
-                              process->simdata->m_host->simdata->smx_host,
-                              t->name, t_simdata->message_size,
-                              t_simdata->rate);
-  /* if the process is suspend, create the action but stop its execution, it will be restart when the sender process resume */
-  if (MSG_process_is_suspended(t_simdata->sender)) {
-    DEBUG1("Process sender (%s) suspended", t_simdata->sender->name);
-    SIMIX_action_set_priority(t_simdata->comm, 0);
-  }
-  process->simdata->waiting_task = t;
-  SIMIX_register_action_to_condition(t_simdata->comm, t_simdata->cond);
-       while (1) {
-               SIMIX_cond_wait(t_simdata->cond, t_simdata->mutex);
-               if (SIMIX_action_get_state(t_simdata->comm) != SURF_ACTION_RUNNING)
-                       break;
-       }
-  SIMIX_unregister_action_to_condition(t_simdata->comm, t_simdata->cond);
-  process->simdata->waiting_task = NULL;
-
-  /* the task has already finished and the pointer must be null */
-  if (t->simdata->sender) {
-    t->simdata->sender->simdata->waiting_task = NULL;
-    /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    //t->simdata->comm = NULL;
-    //t->simdata->compute = NULL;
-  }
-  /* for this process, don't need to change in get function */
-  t->simdata->receiver = NULL;
-  SIMIX_mutex_unlock(t_simdata->mutex);
-
-
-  if (SIMIX_action_get_state(t_simdata->comm) == SURF_ACTION_DONE) {
-    //t_simdata->comm = NULL;
-    SIMIX_action_destroy(t_simdata->comm);
-    t_simdata->comm = NULL;
-               t_simdata->using--;
-    MSG_RETURN(MSG_OK);
-  } else if (SIMIX_host_get_state(h_simdata->smx_host) == 0) {
-    //t_simdata->comm = NULL;
-    SIMIX_action_destroy(t_simdata->comm);
-    t_simdata->comm = NULL;
-               t_simdata->using--;
-    MSG_RETURN(MSG_HOST_FAILURE);
-  } else {
-    //t_simdata->comm = NULL;
-    SIMIX_action_destroy(t_simdata->comm);
-    t_simdata->comm = NULL;
-               t_simdata->using--;
-    MSG_RETURN(MSG_TRANSFER_FAILURE);
-  }
-
-}
-
-/** \ingroup msg_gos_functions
- * \brief Listen on a channel and wait for receiving a task.
- *
- * It takes two parameters.
- * \param task a memory location for storing a #m_task_t. It will
-   hold a task when this function will return. Thus \a task should not
-   be equal to \c NULL and \a *task should be equal to \c NULL. If one of
-   those two condition does not hold, there will be a warning message.
- * \param channel the channel on which the agent should be
-   listening. This value has to be >=0 and < than the maximal
-   number of channels fixed with MSG_set_channel_number().
- * \return #MSG_FATAL if \a task is equal to \c NULL, #MSG_WARNING
- * if \a *task is not equal to \c NULL, and #MSG_OK otherwise.
- */
-MSG_error_t MSG_task_get(m_task_t * task, m_channel_t channel)
-{
-  return MSG_task_get_with_time_out(task, channel, -1);
-}
-
-/** \ingroup msg_gos_functions
- * \brief Listen on a channel and wait for receiving a task with a timeout.
- *
- * It takes three parameters.
- * \param task a memory location for storing a #m_task_t. It will
-   hold a task when this function will return. Thus \a task should not
-   be equal to \c NULL and \a *task should be equal to \c NULL. If one of
-   those two condition does not hold, there will be a warning message.
- * \param channel the channel on which the agent should be
-   listening. This value has to be >=0 and < than the maximal
-   number of channels fixed with MSG_set_channel_number().
- * \param max_duration the maximum time to wait for a task before giving
-    up. In such a case, #MSG_TRANSFER_FAILURE will be returned, \a task 
-    will not be modified and will still be
-    equal to \c NULL when returning. 
- * \return #MSG_FATAL if \a task is equal to \c NULL, #MSG_WARNING
-   if \a *task is not equal to \c NULL, and #MSG_OK otherwise.
- */
-MSG_error_t MSG_task_get_with_time_out(m_task_t * task,
-                                      m_channel_t channel,
-                                      double max_duration)
-{
-  return MSG_task_get_ext(task, channel, max_duration, NULL);
-}
-
-/** \ingroup msg_gos_functions
- * \brief Listen on \a channel and waits for receiving a task from \a host.
- *
- * It takes three parameters.
- * \param task a memory location for storing a #m_task_t. It will
-   hold a task when this function will return. Thus \a task should not
-   be equal to \c NULL and \a *task should be equal to \c NULL. If one of
-   those two condition does not hold, there will be a warning message.
- * \param channel the channel on which the agent should be
-   listening. This value has to be >=0 and < than the maximal
-   number of channels fixed with MSG_set_channel_number().
- * \param host the host that is to be watched.
- * \return #MSG_FATAL if \a task is equal to \c NULL, #MSG_WARNING
-   if \a *task is not equal to \c NULL, and #MSG_OK otherwise.
- */
-MSG_error_t MSG_task_get_from_host(m_task_t * task, int channel,
-                                  m_host_t host)
-{
-  return MSG_task_get_ext(task, channel, -1, host);
-}
-
-/** \ingroup msg_gos_functions
- * \brief Test whether there is a pending communication on a channel.
- *
- * It takes one parameter.
- * \param channel the channel on which the agent should be
-   listening. This value has to be >=0 and < than the maximal
-   number of channels fixed with MSG_set_channel_number().
- * \return 1 if there is a pending communication and 0 otherwise
- */
-int MSG_task_Iprobe(m_channel_t channel)
-{
-  m_host_t h = NULL;
-
-  xbt_assert1((channel >= 0)
-             && (channel < msg_global->max_channel), "Invalid channel %d",
-             channel);
-  CHECK_HOST();
-
-  DEBUG2("Probing on channel %d (%s)", channel, h->name);
-
-  h = MSG_host_self();
-  return (xbt_fifo_get_first_item(h->simdata->mbox[channel]) != NULL);
-}
-
-/** \ingroup msg_gos_functions
- * \brief Test whether there is a pending communication on a channel, and who sent it.
- *
- * It takes one parameter.
- * \param channel the channel on which the agent should be
-   listening. This value has to be >=0 and < than the maximal
-   number of channels fixed with MSG_set_channel_number().
- * \return -1 if there is no pending communication and the PID of the process who sent it otherwise
- */
-int MSG_task_probe_from(m_channel_t channel)
-{
-  m_host_t h = NULL;
-  xbt_fifo_item_t item;
-  m_task_t t;
-
-  xbt_assert1((channel >= 0)
-             && (channel < msg_global->max_channel), "Invalid channel %d",
-             channel);
-  CHECK_HOST();
-
-  h = MSG_host_self();
-
-  DEBUG2("Probing on channel %d (%s)", channel, h->name);
-
-  item = xbt_fifo_get_first_item(h->simdata->mbox[channel]);
-  if ((!item) || (!(t = xbt_fifo_get_item_content(item))))
-    return -1;
-
-  return MSG_process_get_PID(t->simdata->sender);
-}
+                                "Logging specific to MSG (gos)");
 
 /** \ingroup msg_gos_functions
- * \brief Wait for at most \a max_duration second for a task reception
-   on \a channel. 
- * \a PID is updated with the PID of the first process that triggered this event if any.
  *
- * It takes three parameters:
- * \param channel the channel on which the agent should be
-   listening. This value has to be >=0 and < than the maximal.
-   number of channels fixed with MSG_set_channel_number().
- * \param PID a memory location for storing an int.
- * \param max_duration the maximum time to wait for a task before
-    giving up. In the case of a reception, *\a PID will be updated
-    with the PID of the first process to send a task.
- * \return #MSG_HOST_FAILURE if the host is shut down in the meantime
-   and #MSG_OK otherwise.
- */
-MSG_error_t MSG_channel_select_from(m_channel_t channel,
-                                   double max_duration, int *PID)
-{
-  m_host_t h = NULL;
-  simdata_host_t h_simdata = NULL;
-  xbt_fifo_item_t item;
-  m_task_t t;
-  int first_time = 1;
-  smx_cond_t cond;
-
-  xbt_assert1((channel >= 0)
-             && (channel < msg_global->max_channel), "Invalid channel %d",
-             channel);
-  if (PID) {
-    *PID = -1;
-  }
-
-  if (max_duration == 0.0) {
-    *PID = MSG_task_probe_from(channel);
-    MSG_RETURN(MSG_OK);
-  } else {
-    CHECK_HOST();
-    h = MSG_host_self();
-    h_simdata = h->simdata;
-
-    DEBUG2("Probing on channel %d (%s)", channel, h->name);
-    while (!(item = xbt_fifo_get_first_item(h->simdata->mbox[channel]))) {
-      if (max_duration > 0) {
-       if (!first_time) {
-         MSG_RETURN(MSG_OK);
-       }
-      }
-      SIMIX_mutex_lock(h_simdata->mutex);
-      xbt_assert1(!(h_simdata->sleeping[channel]),
-                 "A process is already blocked on this channel %d",
-                 channel);
-      cond = SIMIX_cond_init();
-      h_simdata->sleeping[channel] = cond;     /* I'm waiting. Wake me up when you're ready */
-      if (max_duration > 0) {
-       SIMIX_cond_wait_timeout(cond, h_simdata->mutex, max_duration);
-      } else {
-       SIMIX_cond_wait(cond, h_simdata->mutex);
-      }
-      SIMIX_cond_destroy(cond);
-      SIMIX_mutex_unlock(h_simdata->mutex);
-      if (SIMIX_host_get_state(h_simdata->smx_host) == 0) {
-       MSG_RETURN(MSG_HOST_FAILURE);
-      }
-      h_simdata->sleeping[channel] = NULL;
-      first_time = 0;
-    }
-    if (!item || !(t = xbt_fifo_get_item_content(item))) {
-      MSG_RETURN(MSG_OK);
-    }
-    if (PID) {
-      *PID = MSG_process_get_PID(t->simdata->sender);
-    }
-    MSG_RETURN(MSG_OK);
-  }
-}
-
-
-/** \ingroup msg_gos_functions
-
- * \brief Return the number of tasks waiting to be received on a \a
-   channel and sent by \a host.
- *
- * It takes two parameters.
- * \param channel the channel on which the agent should be
-   listening. This value has to be >=0 and < than the maximal
-   number of channels fixed with MSG_set_channel_number().
- * \param host the host that is to be watched.
- * \return the number of tasks waiting to be received on \a channel
-   and sent by \a host.
- */
-int MSG_task_probe_from_host(int channel, m_host_t host)
-{
-  xbt_fifo_item_t item;
-  m_task_t t;
-  int count = 0;
-  m_host_t h = NULL;
-
-  xbt_assert1((channel >= 0)
-             && (channel < msg_global->max_channel), "Invalid channel %d",
-             channel);
-  CHECK_HOST();
-  h = MSG_host_self();
-
-  DEBUG2("Probing on channel %d (%s)", channel, h->name);
-
-  xbt_fifo_foreach(h->simdata->mbox[channel], item, t, m_task_t) {
-    if (t->simdata->source == host)
-      count++;
-  }
-
-  return count;
-}
-
-/** \ingroup msg_gos_functions \brief Put a task on a channel of an
- * host (with a timeout on the waiting of the destination host) and
- * waits for the end of the transmission.
- *
- * This function is used for describing the behavior of an agent. It
- * takes four parameter.
- * \param task a #m_task_t to send on another location. This task
-   will not be usable anymore when the function will return. There is
-   no automatic task duplication and you have to save your parameters
-   before calling this function. Tasks are unique and once it has been
-   sent to another location, you should not access it anymore. You do
-   not need to call MSG_task_destroy() but to avoid using, as an
-   effect of inattention, this task anymore, you definitely should
-   renitialize it with #MSG_TASK_UNINITIALIZED. Note that this task
-   can be transfered iff it has been correctly created with
-   MSG_task_create().
- * \param dest the destination of the message
- * \param channel the channel on which the agent should put this
-   task. This value has to be >=0 and < than the maximal number of
-   channels fixed with MSG_set_channel_number().
- * \param max_duration the maximum time to wait for a task before giving
-    up. In such a case, #MSG_TRANSFER_FAILURE will be returned, \a task 
-    will not be modified 
- * \return #MSG_FATAL if \a task is not properly initialized and
-   #MSG_OK otherwise. Returns #MSG_HOST_FAILURE if the host on which
-   this function was called was shut down. Returns
-   #MSG_TRANSFER_FAILURE if the transfer could not be properly done
-   (network failure, dest failure, timeout...)
- */
-MSG_error_t MSG_task_put_with_timeout(m_task_t task, m_host_t dest,
-                                     m_channel_t channel,
-                                     double max_duration)
-{
-
-
-  m_process_t process = MSG_process_self();
-  simdata_task_t task_simdata = NULL;
-  m_host_t local_host = NULL;
-  m_host_t remote_host = NULL;
-  CHECK_HOST();
-
-  xbt_assert1((channel >= 0)
-             && (channel < msg_global->max_channel), "Invalid channel %d",
-             channel);
-
-  task_simdata = task->simdata;
-  task_simdata->sender = process;
-  task_simdata->source = MSG_process_get_host(process);
-  xbt_assert0(task_simdata->using == 1,
-             "This task is still being used somewhere else. You cannot send it now. Go fix your code!");
-  task_simdata->comm = NULL;
-
-       task_simdata->using++;
-  local_host = ((simdata_process_t) process->simdata)->m_host;
-  remote_host = dest;
-
-  DEBUG4("Trying to send a task (%g kB) from %s to %s on channel %d",
-        task->simdata->message_size / 1000, local_host->name,
-        remote_host->name, channel);
-
-  SIMIX_mutex_lock(remote_host->simdata->mutex);
-  xbt_fifo_push(((simdata_host_t) remote_host->simdata)->
-               mbox[channel], task);
-
-
-  if (remote_host->simdata->sleeping[channel]) {
-    DEBUG0("Somebody is listening. Let's wake him up!");
-    SIMIX_cond_signal(remote_host->simdata->sleeping[channel]);
-  }
-  SIMIX_mutex_unlock(remote_host->simdata->mutex);
-
-  process->simdata->put_host = dest;
-  process->simdata->put_channel = channel;
-  SIMIX_mutex_lock(task->simdata->mutex);
-  // DEBUG4("Task sent (%g kB) from %s to %s on channel %d, waiting...", task->simdata->message_size/1000,local_host->name, remote_host->name, channel);
-
-  process->simdata->waiting_task = task;
-  if (max_duration > 0) {
-    xbt_ex_t e;
-               double time;
-               double time_elapsed;
-               time = SIMIX_get_clock();
-    TRY {
-               /*verify if the action that ends is the correct. Call the wait_timeout with the new time. If the timeout occurs, an exception is raised */
-                       while (1) {
-                       time_elapsed = SIMIX_get_clock() - time;
-                               SIMIX_cond_wait_timeout(task->simdata->cond, task->simdata->mutex,
-                                               max_duration-time_elapsed);
-                               if ((task->simdata->comm != NULL) &&
-                                               (SIMIX_action_get_state(task->simdata->comm) != SURF_ACTION_RUNNING))
-                                       break;
-                       }
-    } CATCH(e) {
-      if(e.category==timeout_error) {
-       xbt_ex_free(e);
-       /* verify if the timeout happened and the communication didn't started yet */
-       if (task->simdata->comm == NULL) {
-         process->simdata->waiting_task = NULL;
-         xbt_fifo_remove(((simdata_host_t) remote_host->simdata)->
-                         mbox[channel], task);
-         if (task->simdata->receiver) {
-           task->simdata->receiver->simdata->waiting_task = NULL;
-         }
-         task->simdata->sender = NULL;
-         SIMIX_mutex_unlock(task->simdata->mutex);
-         MSG_RETURN(MSG_TRANSFER_FAILURE);
-       }
-      } else {
-       RETHROW;
-      }
-    }
-  } else {
-               while (1) {
-                       SIMIX_cond_wait(task->simdata->cond, task->simdata->mutex);
-                       if (SIMIX_action_get_state(task->simdata->comm) != SURF_ACTION_RUNNING)
-                               break;
-               }
-  }
-
-  DEBUG1("Action terminated %s", task->name);
-  process->simdata->waiting_task = NULL;
-  /* the task has already finished and the pointer must be null */
-  if (task->simdata->receiver) {
-    task->simdata->receiver->simdata->waiting_task = NULL;
-    /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    //      task->simdata->comm = NULL;
-    //task->simdata->compute = NULL;
-  }
-  task->simdata->sender = NULL;
-  SIMIX_mutex_unlock(task->simdata->mutex);
-
-  if (SIMIX_action_get_state(task->simdata->comm) == SURF_ACTION_DONE) {
-    MSG_RETURN(MSG_OK);
-  } else if (SIMIX_host_get_state(local_host->simdata->smx_host) == 0) {
-    MSG_RETURN(MSG_HOST_FAILURE);
-  } else {
-    MSG_RETURN(MSG_TRANSFER_FAILURE);
-  }
-}
-
-/** \ingroup msg_gos_functions
- * \brief Put a task on a channel of an host and waits for the end of the
- * transmission.
- *
- * This function is used for describing the behavior of an agent. It
- * takes three parameter.
- * \param task a #m_task_t to send on another location. This task
-   will not be usable anymore when the function will return. There is
-   no automatic task duplication and you have to save your parameters
-   before calling this function. Tasks are unique and once it has been
-   sent to another location, you should not access it anymore. You do
-   not need to call MSG_task_destroy() but to avoid using, as an
-   effect of inattention, this task anymore, you definitely should
-   renitialize it with #MSG_TASK_UNINITIALIZED. Note that this task
-   can be transfered iff it has been correctly created with
-   MSG_task_create().
- * \param dest the destination of the message
- * \param channel the channel on which the agent should put this
-   task. This value has to be >=0 and < than the maximal number of
-   channels fixed with MSG_set_channel_number().
- * \return #MSG_FATAL if \a task is not properly initialized and
- * #MSG_OK otherwise. Returns #MSG_HOST_FAILURE if the host on which
- * this function was called was shut down. Returns
- * #MSG_TRANSFER_FAILURE if the transfer could not be properly done
- * (network failure, dest failure)
- */
-MSG_error_t MSG_task_put(m_task_t task, m_host_t dest, m_channel_t channel)
-{
-  return MSG_task_put_with_timeout(task, dest, channel, -1.0);
-}
-
-/** \ingroup msg_gos_functions
- * \brief Does exactly the same as MSG_task_put but with a bounded transmition 
- * rate.
- *
- * \sa MSG_task_put
+ * \brief Return the last value returned by a MSG function (except
+ * MSG_get_errno...).
  */
-MSG_error_t MSG_task_put_bounded(m_task_t task,
-                                m_host_t dest, m_channel_t channel,
-                                double max_rate)
+MSG_error_t MSG_get_errno(void)
 {
-  MSG_error_t res = MSG_OK;
-  task->simdata->rate = max_rate;
-  res = MSG_task_put(task, dest, channel);
-  return (res);
+  return PROCESS_GET_ERRNO();
 }
 
 /** \ingroup msg_gos_functions
@@ -595,7 +30,7 @@ MSG_error_t MSG_task_put_bounded(m_task_t task,
  * This function is used for describing the behavior of an agent. It
  * takes only one parameter.
  * \param task a #m_task_t to execute on the location on which the
  agent is running.
+ agent is running.
  * \return #MSG_FATAL if \a task is not properly initialized and
  * #MSG_OK otherwise.
  */
@@ -606,73 +41,97 @@ MSG_error_t MSG_task_execute(m_task_t task)
   CHECK_HOST();
 
   simdata = task->simdata;
-  xbt_assert0((!simdata->compute) && (task->simdata->using == 1),
-             "This task is executed somewhere else. Go fix your code!");
+
+  xbt_assert0(simdata->host_nb == 0,
+              "This is a parallel task. Go to hell.");
+
+#ifdef HAVE_TRACING
+  TRACE_msg_task_execute_start(task);
+#endif
+
+  xbt_assert1((!simdata->compute) && (task->simdata->refcount == 1),
+              "This task is executed somewhere else. Go fix your code! %d",
+              task->simdata->refcount);
 
   DEBUG1("Computing on %s", MSG_process_self()->simdata->m_host->name);
-  simdata->using++;
-  SIMIX_mutex_lock(simdata->mutex);
+
+  if (simdata->computation_amount == 0) {
+#ifdef HAVE_TRACING
+    TRACE_msg_task_execute_end(task);
+#endif
+    return MSG_OK;
+  }
+  simdata->refcount++;
   simdata->compute =
-      SIMIX_action_execute(SIMIX_host_self(), task->name,
-                          simdata->computation_amount);
-  SIMIX_action_set_priority(simdata->compute, simdata->priority);
+      SIMIX_req_host_execute(task->name, SIMIX_host_self(),
+                           simdata->computation_amount);
+  SIMIX_req_host_execution_set_priority(simdata->compute, simdata->priority);
+#ifdef HAVE_TRACING
+  SIMIX_req_set_category(simdata->compute, task->category);
+#endif
 
-  self->simdata->waiting_task = task;
-  SIMIX_register_action_to_condition(simdata->compute, simdata->cond);
-  SIMIX_cond_wait(simdata->cond, simdata->mutex);
-  SIMIX_unregister_action_to_condition(simdata->compute, simdata->cond);
-  self->simdata->waiting_task = NULL;
+  self->simdata->waiting_action = simdata->compute;
+  SIMIX_req_host_execution_wait(simdata->compute);
+  self->simdata->waiting_action = NULL;
 
-  SIMIX_mutex_unlock(simdata->mutex);
-  simdata->using--;
+  simdata->refcount--;
 
-  if (SIMIX_action_get_state(task->simdata->compute) == SURF_ACTION_DONE) {
+  DEBUG2("Execution task '%s' finished in state %d", task->name, SIMIX_req_host_execution_get_state(task->simdata->compute));
+  if (SIMIX_req_host_execution_get_state(task->simdata->compute) == SIMIX_DONE) {
     /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    SIMIX_action_destroy(task->simdata->compute);
+    SIMIX_req_host_execution_destroy(task->simdata->compute);
     simdata->computation_amount = 0.0;
     simdata->comm = NULL;
     simdata->compute = NULL;
+#ifdef HAVE_TRACING
+    TRACE_msg_task_execute_end(task);
+#endif
     MSG_RETURN(MSG_OK);
-  } else if (SIMIX_host_get_state(SIMIX_host_self()) == 0) {
+  } else if (SIMIX_req_host_get_state(SIMIX_host_self()) == 0) {
     /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    SIMIX_action_destroy(task->simdata->compute);
+    SIMIX_req_host_execution_destroy(task->simdata->compute);
     simdata->comm = NULL;
     simdata->compute = NULL;
+#ifdef HAVE_TRACING
+    TRACE_msg_task_execute_end(task);
+#endif
     MSG_RETURN(MSG_HOST_FAILURE);
   } else {
     /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    SIMIX_action_destroy(task->simdata->compute);
+    SIMIX_req_host_execution_destroy(task->simdata->compute);
     simdata->comm = NULL;
     simdata->compute = NULL;
+#ifdef HAVE_TRACING
+    TRACE_msg_task_execute_end(task);
+#endif
     MSG_RETURN(MSG_TASK_CANCELLED);
   }
 }
 
-
 /** \ingroup m_task_management
  * \brief Creates a new #m_task_t (a parallel one....).
  *
- * A constructor for #m_task_t taking six arguments and returning the 
  corresponding object.
+ * A constructor for #m_task_t taking six arguments and returning the
+ corresponding object.
  * \param name a name for the object. It is for user-level information
  and can be NULL.
+ and can be NULL.
  * \param host_nb the number of hosts implied in the parallel task.
  * \param host_list an array of \p host_nb m_host_t.
  * \param computation_amount an array of \p host_nb
  doubles. computation_amount[i] is the total number of operations
  that have to be performed on host_list[i].
+ doubles. computation_amount[i] is the total number of operations
+ that have to be performed on host_list[i].
  * \param communication_amount an array of \p host_nb* \p host_nb doubles.
  * \param data a pointer to any data may want to attach to the new
  object.  It is for user-level information and can be NULL. It can
  be retrieved with the function \ref MSG_task_get_data.
+ object.  It is for user-level information and can be NULL. It can
+ be retrieved with the function \ref MSG_task_get_data.
  * \see m_task_t
  * \return The new corresponding object.
  */
-m_task_t MSG_parallel_task_create(const char *name,
-                                 int host_nb,
-                                 const m_host_t * host_list,
-                                 double *computation_amount,
-                                 double *communication_amount, void *data)
+m_task_t
+MSG_parallel_task_create(const char *name, int host_nb,
+                         const m_host_t * host_list,
+                         double *computation_amount,
+                         double *communication_amount, void *data)
 {
   int i;
   simdata_task_t simdata = xbt_new0(s_simdata_task_t, 1);
@@ -686,12 +145,10 @@ m_task_t MSG_parallel_task_create(const char *name,
   /* Simulator Data */
   simdata->computation_amount = 0;
   simdata->message_size = 0;
-  simdata->cond = SIMIX_cond_init();
-  simdata->mutex = SIMIX_mutex_init();
   simdata->compute = NULL;
   simdata->comm = NULL;
   simdata->rate = -1.0;
-  simdata->using = 1;
+  simdata->refcount = 1;
   simdata->sender = NULL;
   simdata->receiver = NULL;
   simdata->source = NULL;
@@ -705,10 +162,8 @@ m_task_t MSG_parallel_task_create(const char *name,
     simdata->host_list[i] = host_list[i]->simdata->smx_host;
 
   return task;
-
 }
 
-
 MSG_error_t MSG_parallel_task_execute(m_task_t task)
 {
   simdata_task_t simdata = NULL;
@@ -716,52 +171,53 @@ MSG_error_t MSG_parallel_task_execute(m_task_t task)
   CHECK_HOST();
 
   simdata = task->simdata;
-  xbt_assert0((!simdata->compute) && (task->simdata->using == 1),
-             "This task is executed somewhere else. Go fix your code!");
+
+  xbt_assert0((!simdata->compute)
+              && (task->simdata->refcount == 1),
+              "This task is executed somewhere else. Go fix your code!");
 
   xbt_assert0(simdata->host_nb,
-             "This is not a parallel task. Go to hell.");
+              "This is not a parallel task. Go to hell.");
+
+  DEBUG1("Parallel computing on %s", MSG_process_self()->simdata->m_host->name);
+
+  simdata->refcount++;
 
-  DEBUG1("Computing on %s", MSG_process_self()->simdata->m_host->name);
-  simdata->using++;
-  SIMIX_mutex_lock(simdata->mutex);
   simdata->compute =
-      SIMIX_action_parallel_execute(task->name, simdata->host_nb,
-                                   simdata->host_list,
-                                   simdata->comp_amount,
-                                   simdata->comm_amount, 1.0, -1.0);
+      SIMIX_req_host_parallel_execute(task->name, simdata->host_nb,
+                                  simdata->host_list,
+                                  simdata->comp_amount,
+                                  simdata->comm_amount, 1.0, -1.0);
+  DEBUG1("Parallel execution action created: %p", simdata->compute);
 
-  self->simdata->waiting_task = task;
-  SIMIX_register_action_to_condition(simdata->compute, simdata->cond);
-  SIMIX_cond_wait(simdata->cond, simdata->mutex);
-  SIMIX_unregister_action_to_condition(simdata->compute, simdata->cond);
-  self->simdata->waiting_task = NULL;
+  self->simdata->waiting_action = simdata->compute;
+  SIMIX_req_host_execution_wait(simdata->compute);
+  self->simdata->waiting_action = NULL;
 
+  DEBUG2("Finished waiting for execution of action %p, state = %d", simdata->compute, SIMIX_req_host_execution_get_state(task->simdata->compute));
 
-  SIMIX_mutex_unlock(simdata->mutex);
-  simdata->using--;
+  simdata->refcount--;
 
-  if (SIMIX_action_get_state(task->simdata->compute) == SURF_ACTION_DONE) {
+  if (SIMIX_req_host_execution_get_state(task->simdata->compute) == SIMIX_DONE) {
     /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    SIMIX_action_destroy(task->simdata->compute);
+    SIMIX_req_host_execution_destroy(task->simdata->compute);
     simdata->computation_amount = 0.0;
     simdata->comm = NULL;
     simdata->compute = NULL;
     MSG_RETURN(MSG_OK);
-  } else if (SIMIX_host_get_state(SIMIX_host_self()) == 0) {
+  } else if (SIMIX_req_host_get_state(SIMIX_host_self()) == 0) {
     /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    SIMIX_action_destroy(task->simdata->compute);
+    SIMIX_req_host_execution_destroy(task->simdata->compute);
     simdata->comm = NULL;
     simdata->compute = NULL;
     MSG_RETURN(MSG_HOST_FAILURE);
   } else {
     /* action ended, set comm and compute = NULL, the actions is already destroyed in the main function */
-    SIMIX_action_destroy(task->simdata->compute);
+    SIMIX_req_host_execution_destroy(task->simdata->compute);
     simdata->comm = NULL;
     simdata->compute = NULL;
     MSG_RETURN(MSG_TASK_CANCELLED);
   }
-
 }
 
 
@@ -774,511 +230,556 @@ MSG_error_t MSG_parallel_task_execute(m_task_t task)
  */
 MSG_error_t MSG_process_sleep(double nb_sec)
 {
-  smx_action_t act_sleep;
-  m_process_t proc = MSG_process_self();
-  smx_mutex_t mutex;
-  smx_cond_t cond;
+  e_smx_state_t state;
+  /*m_process_t proc = MSG_process_self();*/
+
+#ifdef HAVE_TRACING
+  TRACE_msg_process_sleep_in(MSG_process_self());
+#endif
+
   /* create action to sleep */
-  act_sleep =
-      SIMIX_action_sleep(SIMIX_process_get_host(proc->simdata->s_process),
-                        nb_sec);
-
-  mutex = SIMIX_mutex_init();
-  SIMIX_mutex_lock(mutex);
-  /* create conditional and register action to it */
-  cond = SIMIX_cond_init();
-
-  SIMIX_register_action_to_condition(act_sleep, cond);
-  SIMIX_cond_wait(cond, mutex);
-  SIMIX_unregister_action_to_condition(act_sleep, cond);
-  SIMIX_mutex_unlock(mutex);
-
-  /* remove variables */
-  SIMIX_cond_destroy(cond);
-  SIMIX_mutex_destroy(mutex);
-
-  if (SIMIX_action_get_state(act_sleep) == SURF_ACTION_DONE) {
-    if (SIMIX_host_get_state(SIMIX_host_self()) == SURF_CPU_OFF) {
-      SIMIX_action_destroy(act_sleep);
+  state = SIMIX_req_process_sleep(nb_sec);
+
+  /*proc->simdata->waiting_action = act_sleep;
+
+  FIXME: check if not setting the waiting_action breaks something on msg
+  
+  proc->simdata->waiting_action = NULL;*/
+  
+  if (state == SIMIX_DONE) {
+    if (SIMIX_req_host_get_state(SIMIX_host_self()) == SURF_RESOURCE_OFF) {
+#ifdef HAVE_TRACING
+      TRACE_msg_process_sleep_out(MSG_process_self());
+#endif
       MSG_RETURN(MSG_HOST_FAILURE);
     }
   } else {
-    SIMIX_action_destroy(act_sleep);
+#ifdef HAVE_TRACING
+    TRACE_msg_process_sleep_out(MSG_process_self());
+#endif
     MSG_RETURN(MSG_HOST_FAILURE);
   }
+#ifdef HAVE_TRACING
+  TRACE_msg_process_sleep_out(MSG_process_self());
+#endif
+  MSG_RETURN(MSG_OK);
+}
 
+/** \ingroup msg_gos_functions
+ * \brief Listen on \a channel and waits for receiving a task from \a host.
+ *
+ * It takes three parameters.
+ * \param task a memory location for storing a #m_task_t. It will
+ hold a task when this function will return. Thus \a task should not
+ be equal to \c NULL and \a *task should be equal to \c NULL. If one of
+ those two condition does not hold, there will be a warning message.
+ * \param channel the channel on which the agent should be
+ listening. This value has to be >=0 and < than the maximal
+ number of channels fixed with MSG_set_channel_number().
+ * \param host the host that is to be watched.
+ * \return #MSG_FATAL if \a task is equal to \c NULL, #MSG_WARNING
+ if \a *task is not equal to \c NULL, and #MSG_OK otherwise.
+ */
+MSG_error_t
+MSG_task_get_from_host(m_task_t * task, m_channel_t channel, m_host_t host)
+{
+  return MSG_task_get_ext(task, channel, -1, host);
+}
 
-  MSG_RETURN(MSG_OK);
+/** \ingroup msg_gos_functions
+ * \brief Listen on a channel and wait for receiving a task.
+ *
+ * It takes two parameters.
+ * \param task a memory location for storing a #m_task_t. It will
+ hold a task when this function will return. Thus \a task should not
+ be equal to \c NULL and \a *task should be equal to \c NULL. If one of
+ those two condition does not hold, there will be a warning message.
+ * \param channel the channel on which the agent should be
+ listening. This value has to be >=0 and < than the maximal
+ number of channels fixed with MSG_set_channel_number().
+ * \return #MSG_FATAL if \a task is equal to \c NULL, #MSG_WARNING
+ * if \a *task is not equal to \c NULL, and #MSG_OK otherwise.
+ */
+MSG_error_t MSG_task_get(m_task_t * task, m_channel_t channel)
+{
+  return MSG_task_get_with_timeout(task, channel, -1);
 }
 
 /** \ingroup msg_gos_functions
- * \brief Return the number of MSG tasks currently running on
- * the host of the current running process.
+ * \brief Listen on a channel and wait for receiving a task with a timeout.
+ *
+ * It takes three parameters.
+ * \param task a memory location for storing a #m_task_t. It will
+ hold a task when this function will return. Thus \a task should not
+ be equal to \c NULL and \a *task should be equal to \c NULL. If one of
+ those two condition does not hold, there will be a warning message.
+ * \param channel the channel on which the agent should be
+ listening. This value has to be >=0 and < than the maximal
+ number of channels fixed with MSG_set_channel_number().
+ * \param max_duration the maximum time to wait for a task before giving
+ up. In such a case, #MSG_TRANSFER_FAILURE will be returned, \a task
+ will not be modified and will still be
+ equal to \c NULL when returning.
+ * \return #MSG_FATAL if \a task is equal to \c NULL, #MSG_WARNING
+ if \a *task is not equal to \c NULL, and #MSG_OK otherwise.
  */
-static int MSG_get_msgload(void)
+MSG_error_t
+MSG_task_get_with_timeout(m_task_t * task, m_channel_t channel,
+                          double max_duration)
+{
+  return MSG_task_get_ext(task, channel, max_duration, NULL);
+}
+
+/** \defgroup msg_gos_functions MSG Operating System Functions
+ *  \brief This section describes the functions that can be used
+ *  by an agent for handling some task.
+ */
+
+MSG_error_t
+MSG_task_get_ext(m_task_t * task, m_channel_t channel, double timeout,
+                 m_host_t host)
+{
+  xbt_assert1((channel >= 0)
+              && (channel < msg_global->max_channel), "Invalid channel %d",
+              channel);
+
+  return
+      MSG_mailbox_get_task_ext(MSG_mailbox_get_by_channel
+                               (MSG_host_self(), channel), task, host,
+                               timeout);
+}
+
+MSG_error_t
+MSG_task_receive_from_host(m_task_t * task, const char *alias,
+                           m_host_t host)
+{
+  return MSG_task_receive_ext(task, alias, -1, host);
+}
+
+MSG_error_t MSG_task_receive(m_task_t * task, const char *alias)
 {
-  xbt_die("not implemented yet");
-  return 0;
+  return MSG_task_receive_with_timeout(task, alias, -1);
+}
+
+MSG_error_t
+MSG_task_receive_with_timeout(m_task_t * task, const char *alias,
+                              double timeout)
+{
+  return MSG_task_receive_ext(task, alias, timeout, NULL);
+}
+
+MSG_error_t
+MSG_task_receive_ext(m_task_t * task, const char *alias, double timeout,
+                     m_host_t host)
+{
+  DEBUG1
+      ("MSG_task_receive_ext: Trying to receive a message on mailbox '%s'",
+       alias);
+  return MSG_mailbox_get_task_ext(MSG_mailbox_get_by_alias(alias), task,
+                                  host, timeout);
 }
 
 /** \ingroup msg_gos_functions
+ * \brief Send a task on a channel.
  *
- * \brief Return the last value returned by a MSG function (except
- * MSG_get_errno...).
+ * This function takes two parameter.
+ * \param task a #m_task_t to send on another location.
+ * \param alias the channel on which the agent should put this
+ task. This value has to be >=0 and < than the maximal number of
+ channels fixed with MSG_set_channel_number().
+ * \return the msg_comm_t communication.
  */
-MSG_error_t MSG_get_errno(void)
+msg_comm_t MSG_task_isend(m_task_t task, const char *alias)
 {
-  return PROCESS_GET_ERRNO();
+  simdata_task_t t_simdata = NULL;
+  m_process_t process = MSG_process_self();
+  msg_mailbox_t mailbox = MSG_mailbox_get_by_alias(alias);
+
+  CHECK_HOST();
+
+  /* FIXME: these functions are not tracable */
+
+  /* Prepare the task to send */
+  t_simdata = task->simdata;
+  t_simdata->sender = process;
+  t_simdata->source = MSG_host_self();
+
+  xbt_assert0(t_simdata->refcount == 1,
+              "This task is still being used somewhere else. You cannot send it now. Go fix your code!");
+
+  t_simdata->refcount++;
+  msg_global->sent_msg++;
+  process->simdata->waiting_task = task;
+
+  /* Send it by calling SIMIX network layer */
+
+  return SIMIX_req_comm_isend(mailbox, t_simdata->message_size,
+                             t_simdata->rate, task, sizeof(void *),
+                             &t_simdata->comm);
+}
+
+/** \ingroup msg_gos_functions
+ * \brief Listen on a channel for receiving a task from an asynchronous communication.
+ *
+ * It takes two parameters.
+ * \param task a memory location for storing a #m_task_t.
+ * \param alias the channel on which the agent should be
+ listening. This value has to be >=0 and < than the maximal
+ number of channels fixed with MSG_set_channel_number().
+ * \return the msg_comm_t communication.
+ */
+msg_comm_t MSG_task_irecv(m_task_t * task, const char *alias)
+{
+  smx_rdv_t rdv = MSG_mailbox_get_by_alias(alias);
+
+  CHECK_HOST();
+
+  /* FIXME: these functions are not tracable */
+
+  /* Sanity check */
+  xbt_assert0(task, "Null pointer for the task storage");
+
+  if (*task)
+    CRITICAL0
+        ("MSG_task_get() was asked to write in a non empty task struct.");
+
+  /* Try to receive it by calling SIMIX network layer */
+  return SIMIX_req_comm_irecv(rdv, task, NULL);
+}
+
+/** \ingroup msg_gos_functions
+ * \brief Test the status of a communication.
+ *
+ * It takes one parameter.
+ * \param comm the communication to test.
+ * \return the status of the communication:
+ *             TRUE : the communication is completed
+ *             FALSE: the communication is incompleted
+ * If the status is FALSE, don't forget to use MSG_process_sleep() after the test.
+ */
+int MSG_comm_test(msg_comm_t comm)
+{
+  return SIMIX_req_comm_test(comm);
+}
+
+/** \ingroup msg_gos_functions
+ * \brief After received TRUE to MSG_comm_test(), the communication must be destroyed.
+ *
+ * It takes one parameter.
+ * \param comm the communication to destroy.
+ */
+void MSG_comm_destroy(msg_comm_t comm)
+{
+  if (SIMIX_req_comm_get_src_proc(comm) != SIMIX_process_self()) {
+    m_task_t task;
+    task = (m_task_t) SIMIX_req_comm_get_src_buff(comm);
+    task->simdata->refcount--;
+  }
+  SIMIX_req_comm_destroy(comm);
+}
+
+/** \ingroup msg_gos_functions
+ * \brief Wait for the completion of a communication.
+ *
+ * It takes two parameters.
+ * \param comm the communication to wait.
+ * \param timeout Wait until the communication terminates or the timeout occurs
+ * \return MSG_error_t
+ */
+MSG_error_t MSG_comm_wait(msg_comm_t comm, double timeout)
+{
+  xbt_ex_t e;
+  MSG_error_t res = MSG_OK;
+  TRY {
+    SIMIX_req_comm_wait(comm, timeout);
+
+    if (SIMIX_req_comm_get_src_proc(comm) != SIMIX_process_self()) {
+      m_task_t task;
+      task = (m_task_t) SIMIX_req_comm_get_src_buff(comm);
+      task->simdata->refcount--;
+    }
+
+    /* FIXME: these functions are not tracable */
+  }
+  CATCH(e) {
+    switch (e.category) {
+    case host_error:
+      res = MSG_HOST_FAILURE;
+      break;
+    case network_error:
+      res = MSG_TRANSFER_FAILURE;
+      break;
+    case timeout_error:
+      res = MSG_TIMEOUT;
+      break;
+    default:
+      xbt_die(bprintf("Unhandled SIMIX network exception: %s", e.msg));
+    }
+    xbt_ex_free(e);
+  }
+  return res;
 }
 
-MSG_error_t 
-MSG_task_receive_ext(m_task_t* task, const char* alias, double timeout, m_host_t host)
+/** \ingroup msg_gos_functions
+* \brief This function is called by a sender and permit to wait for each communication
+*
+* It takes three parameters.
+* \param comm a vector of communication
+* \param nb_elem is the size of the comm vector
+* \param timeout for each call of  MSG_comm_wait
+*/
+void MSG_comm_waitall(msg_comm_t * comm, int nb_elem, double timeout)
 {
-       m_process_t process = MSG_process_self();
-       m_task_t t = NULL;
-       m_host_t h = NULL;
-       simdata_task_t t_simdata = NULL;
-       simdata_host_t h_simdata = NULL;
-       int first_time = 1;
-       xbt_fifo_item_t item = NULL;
-       
-       smx_cond_t cond = NULL; //conditional wait if the task isn't on the channel yet
-       
-       /* get the mailbox from the alias (if the mailbox doesn't exist, create it) */
-       msg_mailbox_t mailbox = MSG_mailbox_get_by_alias(alias);
-       
-       CHECK_HOST();
-       
-       /* Sanity check */
-       xbt_assert0(task, "Null pointer for the task storage");
-       
-       if (*task)
-               CRITICAL0("MSG_task_get() was asked to write in a non empty task struct.");
-       
-       /* Get the task */
-       h = MSG_host_self();
-       h_simdata = h->simdata;
-       
-       DEBUG2("Waiting for a task on channel aliased by %s (%s)", alias, h->name);
-       
-       SIMIX_mutex_lock(h->simdata->mutex);
-       
-       while (1) 
-       {
-               /* if the mailbox is empty (has no task */
-               if(!MSG_mailbox_is_empty(mailbox))
-               {
-                       if(!host) 
-                       {
-                               /* pop the head of the mailbox */
-                               t = MSG_mailbox_pop_head(mailbox);
-                               break;
-                       } 
-                       else 
-                       {
-                               /* get the first task of the host */
-                               if(NULL != (t = MSG_mailbox_get_first_host_task(mailbox,host)))
-                                       break;
-                       }
-               }
-       
-               if(timeout > 0) 
-               {
-                       if (!first_time) 
-                       {
-                               SIMIX_mutex_unlock(h->simdata->mutex);
-                               /* set the simix condition of the mailbox to NULL */
-                               MSG_mailbox_set_cond(mailbox, NULL);
-                               SIMIX_cond_destroy(cond);
-                               MSG_RETURN(MSG_TRANSFER_FAILURE);
-                       }
-               }
-               
-               xbt_assert1(!MSG_mailbox_get_cond(mailbox),"A process is already blocked on the channel aliased by %s", alias);
-               
-               cond = SIMIX_cond_init();
-               
-               /* set the condition of the mailbox */
-               MSG_mailbox_set_cond(mailbox, cond);
-               
-               if (timeout > 0)
-                       SIMIX_cond_wait_timeout(cond, h->simdata->mutex, timeout);
-               else 
-                       SIMIX_cond_wait(MSG_mailbox_get_cond(mailbox), h->simdata->mutex);
-                       
-       
-               if (SIMIX_host_get_state(h_simdata->smx_host) == 0)
-                       MSG_RETURN(MSG_HOST_FAILURE);
-       
-               first_time = 0;
-       }
-       
-       SIMIX_mutex_unlock(h->simdata->mutex);
-       
-       DEBUG1("OK, got a task (%s)", t->name);
-       /* clean conditional */
-       if (cond) 
-       {
-               SIMIX_cond_destroy(cond);
-               
-               MSG_mailbox_set_cond(mailbox,NULL);
-       }
-       
-       t_simdata = t->simdata;
-       t_simdata->receiver = process;
-       *task = t;
-       
-       SIMIX_mutex_lock(t_simdata->mutex);
-       
-       /* Transfer */
-       /* create SIMIX action to the communication */
-       t_simdata->comm = SIMIX_action_communicate(
-                                                                                               t_simdata->sender->simdata->m_host->simdata->smx_host,
-                                                                                               process->simdata->m_host->simdata->smx_host,
-                                                                                               t->name, 
-                                                                                               t_simdata->message_size,
-                                                                                               t_simdata->rate
-                                                                                       );
-       
-       /* if the process is suspend, create the action but stop its execution, it will be restart when the sender process resume */
-       if (MSG_process_is_suspended(t_simdata->sender)) 
-       {
-               DEBUG1("Process sender (%s) suspended", t_simdata->sender->name);
-               SIMIX_action_set_priority(t_simdata->comm, 0);
-       }
-       
-       process->simdata->waiting_task = t;
-       SIMIX_register_action_to_condition(t_simdata->comm, t_simdata->cond);
-       
-       while (1) 
-       {
-               SIMIX_cond_wait(t_simdata->cond, t_simdata->mutex);
-               
-               if (SIMIX_action_get_state(t_simdata->comm) != SURF_ACTION_RUNNING)
-                       break;
-       }
-       
-       SIMIX_unregister_action_to_condition(t_simdata->comm, t_simdata->cond);
-               process->simdata->waiting_task = NULL;
-       
-       /* the task has already finished and the pointer must be null */
-       if (t->simdata->sender) 
-       {
-               t->simdata->sender->simdata->waiting_task = NULL;
-       }
-       
-       /* for this process, don't need to change in get function */
-       t->simdata->receiver = NULL;
-       SIMIX_mutex_unlock(t_simdata->mutex);
-       
-       
-       if (SIMIX_action_get_state(t_simdata->comm) == SURF_ACTION_DONE) 
-       {
-               SIMIX_action_destroy(t_simdata->comm);
-               t_simdata->comm = NULL;
-               t_simdata->using--;
-               MSG_RETURN(MSG_OK);
-       } 
-       else if (SIMIX_host_get_state(h_simdata->smx_host) == 0) 
-       {
-               SIMIX_action_destroy(t_simdata->comm);
-               t_simdata->comm = NULL;
-               t_simdata->using--;
-               MSG_RETURN(MSG_HOST_FAILURE);
-       } 
-       else 
-       {
-               SIMIX_action_destroy(t_simdata->comm);
-               t_simdata->comm = NULL;
-               t_simdata->using--;
-               MSG_RETURN(MSG_TRANSFER_FAILURE);
-       }
+  int i = 0;
+  for (i = 0; i < nb_elem; i++) {
+    MSG_comm_wait(comm[i], timeout);
+  }
 }
 
-MSG_error_t 
-MSG_task_receive_with_time_out(m_task_t * task, const char* alias, double timeout)
+/** \ingroup msg_gos_functions
+* \brief This function wait for the first completed communication
+*
+* It takes on parameter.
+* \param comms a vector of communication
+* \return the position of the completed communication from the xbt_dynar_t.
+*/
+int MSG_comm_waitany(xbt_dynar_t comms)
 {
-       return MSG_task_receive_ext(task, alias, timeout, NULL);                
+  return SIMIX_req_comm_waitany(comms);
 }
-                            
-MSG_error_t 
-MSG_task_receive(m_task_t * task, const char* alias)
+
+/** \ingroup msg_gos_functions
+* \brief This function wait for the first completed communication
+*
+* It takes on parameter.
+* \param comms a vector of communication
+* \return the position of the completed communication, if any, or -1 if none was completed
+*/
+int MSG_comm_testany(xbt_dynar_t comms)
 {
-       return MSG_task_receive_with_time_out(task, alias, -1); 
+  return SIMIX_req_comm_testany(comms);
 }
 
-int 
-MSG_task_listen(const char* alias)
+m_task_t MSG_comm_get_task(msg_comm_t comm)
 {
-       CHECK_HOST();
-       
-       DEBUG2("Probing on channel aliased by %s (%s)", alias, MSG_host_self()->name);
-       
-       return !MSG_mailbox_is_empty(MSG_mailbox_get_by_alias(alias));
+  xbt_assert0(comm, "Invalid parameters");
+  return (m_task_t) SIMIX_req_comm_get_src_buff(comm);
 }
 
-int 
-MSG_task_listen_from_host(const char* alias, m_host_t host)
+/** \ingroup msg_gos_functions
+ * \brief Put a task on a channel of an host and waits for the end of the
+ * transmission.
+ *
+ * This function is used for describing the behavior of an agent. It
+ * takes three parameter.
+ * \param task a #m_task_t to send on another location. This task
+ will not be usable anymore when the function will return. There is
+ no automatic task duplication and you have to save your parameters
+ before calling this function. Tasks are unique and once it has been
+ sent to another location, you should not access it anymore. You do
+ not need to call MSG_task_destroy() but to avoid using, as an
+ effect of inattention, this task anymore, you definitely should
+ renitialize it with #MSG_TASK_UNINITIALIZED. Note that this task
+ can be transfered iff it has been correctly created with
+ MSG_task_create().
+ * \param dest the destination of the message
+ * \param channel the channel on which the agent should put this
+ task. This value has to be >=0 and < than the maximal number of
+ channels fixed with MSG_set_channel_number().
+ * \return #MSG_FATAL if \a task is not properly initialized and
+ * #MSG_OK otherwise. Returns #MSG_HOST_FAILURE if the host on which
+ * this function was called was shut down. Returns
+ * #MSG_TRANSFER_FAILURE if the transfer could not be properly done
+ * (network failure, dest failure)
+ */
+MSG_error_t MSG_task_put(m_task_t task, m_host_t dest, m_channel_t channel)
 {
+  return MSG_task_put_with_timeout(task, dest, channel, -1.0);
+}
 
-       return MSG_mailbox_get_count_host_tasks(MSG_mailbox_get_by_alias(alias),host);
-                       
+/** \ingroup msg_gos_functions
+ * \brief Does exactly the same as MSG_task_put but with a bounded transmition
+ * rate.
+ *
+ * \sa MSG_task_put
+ */
+MSG_error_t
+MSG_task_put_bounded(m_task_t task, m_host_t dest, m_channel_t channel,
+                     double maxrate)
+{
+  task->simdata->rate = maxrate;
+  return MSG_task_put(task, dest, channel);
 }
 
-MSG_error_t 
-MSG_alias_select_from(const char* alias, double timeout, int* PID)
+/** \ingroup msg_gos_functions \brief Put a task on a channel of an
+ * host (with a timeout on the waiting of the destination host) and
+ * waits for the end of the transmission.
+ *
+ * This function is used for describing the behavior of an agent. It
+ * takes four parameter.
+ * \param task a #m_task_t to send on another location. This task
+ will not be usable anymore when the function will return. There is
+ no automatic task duplication and you have to save your parameters
+ before calling this function. Tasks are unique and once it has been
+ sent to another location, you should not access it anymore. You do
+ not need to call MSG_task_destroy() but to avoid using, as an
+ effect of inattention, this task anymore, you definitely should
+ renitialize it with #MSG_TASK_UNINITIALIZED. Note that this task
+ can be transfered iff it has been correctly created with
+ MSG_task_create().
+ * \param dest the destination of the message
+ * \param channel the channel on which the agent should put this
+ task. This value has to be >=0 and < than the maximal number of
+ channels fixed with MSG_set_channel_number().
+ * \param timeout the maximum time to wait for a task before giving
+ up. In such a case, #MSG_TRANSFER_FAILURE will be returned, \a task
+ will not be modified
+ * \return #MSG_FATAL if \a task is not properly initialized and
+#MSG_OK otherwise. Returns #MSG_HOST_FAILURE if the host on which
+this function was called was shut down. Returns
+#MSG_TRANSFER_FAILURE if the transfer could not be properly done
+(network failure, dest failure, timeout...)
+ */
+MSG_error_t
+MSG_task_put_with_timeout(m_task_t task, m_host_t dest,
+                          m_channel_t channel, double timeout)
 {
-       m_host_t h = NULL;
-       simdata_host_t h_simdata = NULL;
-       m_task_t t;
-       int first_time = 1;
-       smx_cond_t cond;
-       msg_mailbox_t mailbox;
-       
-       if (PID) 
-       {
-               *PID = -1;
-       }
-       
-       if(timeout == 0.0) 
-       {
-               *PID = MSG_task_listen_from(alias);
-               MSG_RETURN(MSG_OK);
-       } 
-       else 
-       {
-               CHECK_HOST();
-               h = MSG_host_self();
-               h_simdata = h->simdata;
-       
-               DEBUG2("Probing on alias %s (%s)", alias, h->name);
-               
-               mailbox = MSG_mailbox_get_by_alias(alias);      
-               
-               while(MSG_mailbox_is_empty(mailbox))
-               {
-                       if(timeout > 0) 
-                       {
-                               if (!first_time) 
-                               {
-                                       MSG_RETURN(MSG_OK);
-                               }
-                       }
-                       
-                       SIMIX_mutex_lock(h_simdata->mutex);
-                       
-                       xbt_assert1(!MSG_mailbox_get_cond(mailbox),"A process is already blocked on this alias %s",alias);
-                       
-                       cond = SIMIX_cond_init();
-                       
-                       MSG_mailbox_set_cond(mailbox, cond);
-                       
-                       if (timeout > 0) 
-                       {
-                               SIMIX_cond_wait_timeout(cond, h_simdata->mutex, timeout);
-                       } 
-                       else 
-                       {
-                               SIMIX_cond_wait(cond, h_simdata->mutex);
-                       }
-                       
-                       SIMIX_cond_destroy(cond);
-                       SIMIX_mutex_unlock(h_simdata->mutex);
-                       
-                       if (SIMIX_host_get_state(h_simdata->smx_host) == 0) 
-                       {
-                               MSG_RETURN(MSG_HOST_FAILURE);
-                       }
-                       
-                       MSG_mailbox_set_cond(mailbox,NULL);
-                       first_time = 0;
-               }
-               
-               if(NULL == (t = MSG_mailbox_get_head(mailbox)))
-                       MSG_RETURN(MSG_OK);
-                               
-               
-               if (PID) 
-               {
-                       *PID = MSG_process_get_PID(t->simdata->sender);
-               }
-               
-               MSG_RETURN(MSG_OK);
-       }
+  xbt_assert1((channel >= 0)
+              && (channel < msg_global->max_channel), "Invalid channel %d",
+              channel);
+
+  DEBUG1("MSG_task_put_with_timout: Trying to send a task to '%s'", dest->name);
+  return
+      MSG_mailbox_put_with_timeout(MSG_mailbox_get_by_channel
+                                   (dest, channel), task, timeout);
 }
-                                   
-MSG_error_t 
-MSG_task_send_with_timeout(m_task_t task, const char* alias, double timeout)
+
+MSG_error_t MSG_task_send(m_task_t task, const char *alias)
 {
-       m_process_t process = MSG_process_self();
-       const char* hostname;
-       simdata_task_t task_simdata = NULL;
-       m_host_t local_host = NULL;
-       m_host_t remote_host = NULL;
-       smx_cond_t cond = NULL;
-       
-       /* get the mailbox from the alias (if the mailbox doesn't exist, create it) */
-       msg_mailbox_t mailbox = MSG_mailbox_get_by_alias(alias);
-
-       CHECK_HOST();
-       
-       task_simdata = task->simdata;
-       task_simdata->sender = process;
-       task_simdata->source = MSG_process_get_host(process);
-       
-       xbt_assert0(task_simdata->using == 1,"This task is still being used somewhere else. You cannot send it now. Go fix your code!");
-       
-       task_simdata->comm = NULL;
-       
-       task_simdata->using++;
-       local_host = ((simdata_process_t) process->simdata)->m_host;
-       
-       /* get the host name containing the mailbox */
-       hostname = MSG_mailbox_get_hostname(mailbox);
-
-       remote_host = MSG_get_host_by_name(hostname);
-
-       if(NULL == remote_host)
-               THROW1(not_found_error,0,"Host %s not fount", hostname);
-
-
-       DEBUG4("Trying to send a task (%g kB) from %s to %s on the channel aliased by the alias %s",task->simdata->message_size / 1000, local_host->name,remote_host->name, MSG_mailbox_get_alias(mailbox));
-       
-       SIMIX_mutex_lock(remote_host->simdata->mutex);
-
-       /* put the task in the mailbox */
-       MSG_mailbox_put(mailbox,task);
-       
-       if(NULL != (cond = MSG_mailbox_get_cond(mailbox)))
-       {
-               DEBUG0("Somebody is listening. Let's wake him up!");
-               SIMIX_cond_signal(cond);
-       }
-
-       
-       
-       SIMIX_mutex_unlock(remote_host->simdata->mutex);
-       
-       SIMIX_mutex_lock(task->simdata->mutex);
-
-       process->simdata->waiting_task = task;
-       
-       if(timeout > 0) 
-       {
-               xbt_ex_t e;
-               double time;
-               double time_elapsed;
-               time = SIMIX_get_clock();
-               
-               TRY 
-               {
-                       /*verify if the action that ends is the correct. Call the wait_timeout with the new time. If the timeout occurs, an exception is raised */
-                       while (1) 
-                       {
-                               time_elapsed = SIMIX_get_clock() - time;
-                               SIMIX_cond_wait_timeout(task->simdata->cond, task->simdata->mutex,timeout - time_elapsed);
-                               
-                               if ((task->simdata->comm != NULL) && (SIMIX_action_get_state(task->simdata->comm) != SURF_ACTION_RUNNING))
-                                       break;
-                       }
-               } 
-               CATCH(e) 
-               {
-                       if(e.category==timeout_error) 
-                       {
-                               xbt_ex_free(e);
-                               /* verify if the timeout happened and the communication didn't started yet */
-                               if (task->simdata->comm == NULL) 
-                               {
-                                       process->simdata->waiting_task = NULL;
-                                       
-                                       /* remove the task from the mailbox */
-                                       MSG_mailbox_remove(mailbox,task);
-                                       
-                                       if (task->simdata->receiver) 
-                                       {
-                                               task->simdata->receiver->simdata->waiting_task = NULL;
-                                       }
-                                       
-                                       task->simdata->sender = NULL;
-                                       
-                                       SIMIX_mutex_unlock(task->simdata->mutex);
-                                       MSG_RETURN(MSG_TRANSFER_FAILURE);
-                               }
-                       } 
-                       else 
-                       {
-                               RETHROW;
-                       }
-               }
-       } 
-       else 
-       {
-               while (1) 
-               {
-                       SIMIX_cond_wait(task->simdata->cond, task->simdata->mutex);
-                       
-                       if (SIMIX_action_get_state(task->simdata->comm) != SURF_ACTION_RUNNING)
-                               break;
-               }
-       }
-       
-       DEBUG1("Action terminated %s", task->name);
-       process->simdata->waiting_task = NULL;
-       
-       /* the task has already finished and the pointer must be null */
-       if (task->simdata->receiver) 
-       {
-               task->simdata->receiver->simdata->waiting_task = NULL;
-       }
-       
-       task->simdata->sender = NULL;
-       SIMIX_mutex_unlock(task->simdata->mutex);
-
-       
-       if (SIMIX_action_get_state(task->simdata->comm) == SURF_ACTION_DONE)
-       {
-               MSG_RETURN(MSG_OK);
-       } 
-       else if (SIMIX_host_get_state(local_host->simdata->smx_host) == 0) 
-       {
-               MSG_RETURN(MSG_HOST_FAILURE);
-       } 
-       else 
-       {
-               MSG_RETURN(MSG_TRANSFER_FAILURE);
-       }
+  DEBUG1("MSG_task_send: Trying to send a message on mailbox '%s'", alias);
+  return MSG_task_send_with_timeout(task, alias, -1);
 }
 
-MSG_error_t 
-MSG_task_send(m_task_t task,const char* alias)
+
+MSG_error_t
+MSG_task_send_bounded(m_task_t task, const char *alias, double maxrate)
 {
-       return MSG_task_send_with_timeout(task, alias, -1);
+  task->simdata->rate = maxrate;
+  return MSG_task_send(task, alias);
 }
 
 
-MSG_error_t 
-MSG_task_send_bounded(m_task_t task, const char* alias, double rate)
+MSG_error_t
+MSG_task_send_with_timeout(m_task_t task, const char *alias,
+                           double timeout)
 {
-       task->simdata->rate = rate;
-       return MSG_task_send(task, alias);
+  return MSG_mailbox_put_with_timeout(MSG_mailbox_get_by_alias(alias),
+                                      task, timeout);
 }
 
-int
-MSG_task_listen_from(const char* alias)
+int MSG_task_listen(const char *alias)
 {
-       m_host_t h = NULL;
-       m_task_t t;
+  CHECK_HOST();
 
-       CHECK_HOST();
+  return !MSG_mailbox_is_empty(MSG_mailbox_get_by_alias(alias));
+}
 
-       h = MSG_host_self();
+/** \ingroup msg_gos_functions
+ * \brief Test whether there is a pending communication on a channel.
+ *
+ * It takes one parameter.
+ * \param channel the channel on which the agent should be
+ listening. This value has to be >=0 and < than the maximal
+ number of channels fixed with MSG_set_channel_number().
+ * \return 1 if there is a pending communication and 0 otherwise
+ */
+int MSG_task_Iprobe(m_channel_t channel)
+{
+  xbt_assert1((channel >= 0)
+              && (channel < msg_global->max_channel), "Invalid channel %d",
+              channel);
 
-       DEBUG2("Probing on alias %s(%s)", alias, h->name);
+  CHECK_HOST();
+
+  return
+      !MSG_mailbox_is_empty(MSG_mailbox_get_by_channel
+                            (MSG_host_self(), channel));
+}
+
+/** \ingroup msg_gos_functions
+
+ * \brief Return the number of tasks waiting to be received on a \a
+ channel and sent by \a host.
+ *
+ * It takes two parameters.
+ * \param channel the channel on which the agent should be
+ listening. This value has to be >=0 and < than the maximal
+ number of channels fixed with MSG_set_channel_number().
+ * \param host the host that is to be watched.
+ * \return the number of tasks waiting to be received on \a channel
+ and sent by \a host.
+ */
+int MSG_task_probe_from_host(int channel, m_host_t host)
+{
+  xbt_assert1((channel >= 0)
+              && (channel < msg_global->max_channel), "Invalid channel %d",
+              channel);
+
+  CHECK_HOST();
+
+  return
+      MSG_mailbox_get_count_host_waiting_tasks(MSG_mailbox_get_by_channel
+                                               (MSG_host_self(), channel),
+                                               host);
+
+}
 
-       if(NULL == (t = MSG_mailbox_get_head(MSG_mailbox_get_by_alias(alias))))
-               return -1;
+int MSG_task_listen_from_host(const char *alias, m_host_t host)
+{
+  CHECK_HOST();
+
+  return
+      MSG_mailbox_get_count_host_waiting_tasks(MSG_mailbox_get_by_alias
+                                               (alias), host);
+}
+
+/** \ingroup msg_gos_functions
+ * \brief Test whether there is a pending communication on a channel, and who sent it.
+ *
+ * It takes one parameter.
+ * \param channel the channel on which the agent should be
+ listening. This value has to be >=0 and < than the maximal
+ number of channels fixed with MSG_set_channel_number().
+ * \return -1 if there is no pending communication and the PID of the process who sent it otherwise
+ */
+int MSG_task_probe_from(m_channel_t channel)
+{
+  m_task_t task;
+
+  CHECK_HOST();
+
+  xbt_assert1((channel >= 0)
+              && (channel < msg_global->max_channel), "Invalid channel %d",
+              channel);
+
+  if (NULL ==
+      (task =
+       MSG_mailbox_get_head(MSG_mailbox_get_by_channel
+                            (MSG_host_self(), channel))))
+    return -1;
+
+  return MSG_process_get_PID(task->simdata->sender);
+}
+
+int MSG_task_listen_from(const char *alias)
+{
+  m_task_t task;
+
+  CHECK_HOST();
+
+  if (NULL ==
+      (task = MSG_mailbox_get_head(MSG_mailbox_get_by_alias(alias))))
+    return -1;
 
-       return MSG_process_get_PID(t->simdata->sender);
+  return MSG_process_get_PID(task->simdata->sender);
 }
-