X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/5b26ea89fedaa063150a60c66efc5932b4ae37b5..23f5bf52cc58cf837840f231cf638e9fcd45097b:/src/simix/smx_network.c

diff --git a/src/simix/smx_network.c b/src/simix/smx_network.c
index 31bec78c2c..82313fbb6e 100644
--- a/src/simix/smx_network.c
+++ b/src/simix/smx_network.c
@@ -4,7 +4,7 @@
 /* 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 "private.h"
+#include "smx_private.h"
 #include "xbt/log.h"
 #include "mc/mc.h"
 #include "xbt/dict.h"
@@ -13,20 +13,25 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_network, simix,
                                 "Logging specific to SIMIX (network)");
 
 static xbt_dict_t rdv_points = NULL;
-unsigned long int smx_total_comms = 0;
+XBT_IMPORT_NO_EXPORT(unsigned long int) smx_total_comms = 0;
 
-static void SIMIX_waitany_req_remove_from_actions(smx_req_t req);
+static void SIMIX_waitany_remove_simcall_from_actions(smx_simcall_t simcall);
 static void SIMIX_comm_copy_data(smx_action_t comm);
 static smx_action_t SIMIX_comm_new(e_smx_comm_type_t type);
 static XBT_INLINE void SIMIX_rdv_push(smx_rdv_t rdv, smx_action_t comm);
-static XBT_INLINE void SIMIX_rdv_remove(smx_rdv_t rdv, smx_action_t comm);
-static smx_action_t SIMIX_rdv_get_request(smx_rdv_t rdv, e_smx_comm_type_t type,
-					  int (*match_fun)(void *, void *), void *);
+static smx_action_t SIMIX_fifo_probe_comm(xbt_fifo_t fifo, e_smx_comm_type_t type,
+                                        int (*match_fun)(void *, void *,smx_action_t),
+                                        void *user_data, smx_action_t my_action);
+static smx_action_t SIMIX_fifo_get_comm(xbt_fifo_t fifo, e_smx_comm_type_t type,
+                                        int (*match_fun)(void *, void *,smx_action_t),
+                                        void *user_data, smx_action_t my_action);
 static void SIMIX_rdv_free(void *data);
 
 void SIMIX_network_init(void)
 {
-  rdv_points = xbt_dict_new();
+  rdv_points = xbt_dict_new_homogeneous(SIMIX_rdv_free);
+  if(MC_is_active())
+    MC_ignore_data_bss(&smx_total_comms, sizeof(smx_total_comms));
 }
 
 void SIMIX_network_exit(void)
@@ -40,16 +45,20 @@ void SIMIX_network_exit(void)
 
 smx_rdv_t SIMIX_rdv_create(const char *name)
 {
-  /* two processes may have pushed the same rdv_create request at the same time */
+  /* two processes may have pushed the same rdv_create simcall at the same time */
   smx_rdv_t rdv = name ? xbt_dict_get_or_null(rdv_points, name) : NULL;
 
   if (!rdv) {
     rdv = xbt_new0(s_smx_rvpoint_t, 1);
     rdv->name = name ? xbt_strdup(name) : NULL;
     rdv->comm_fifo = xbt_fifo_new();
+    rdv->done_comm_fifo = xbt_fifo_new();
+    rdv->permanent_receiver=NULL;
+
+    XBT_DEBUG("Creating a mailbox at %p with name %s\n", rdv, name);
 
     if (rdv->name)
-      xbt_dict_set(rdv_points, rdv->name, rdv, SIMIX_rdv_free);
+      xbt_dict_set(rdv_points, rdv->name, rdv, NULL);
   }
   return rdv;
 }
@@ -62,13 +71,20 @@ void SIMIX_rdv_destroy(smx_rdv_t rdv)
 
 void SIMIX_rdv_free(void *data)
 {
+  XBT_DEBUG("rdv free %p", data);
   smx_rdv_t rdv = (smx_rdv_t) data;
-  if (rdv->name)
-    xbt_free(rdv->name);
+  xbt_free(rdv->name);
   xbt_fifo_free(rdv->comm_fifo);
+  xbt_fifo_free(rdv->done_comm_fifo);
+
   xbt_free(rdv);  
 }
 
+xbt_dict_t SIMIX_get_rdv_points()
+{
+  return rdv_points;
+}
+
 smx_rdv_t SIMIX_rdv_get_by_name(const char *name)
 {
   return xbt_dict_get_or_null(rdv_points, name);
@@ -94,9 +110,29 @@ smx_action_t SIMIX_rdv_get_head(smx_rdv_t rdv)
 }
 
 /**
- *  \brief Push a communication request into a rendez-vous point
+ *  \brief get the receiver (process associated to the mailbox)
+ *  \param rdv The rendez-vous point
+ *  \return process The receiving process (NULL if not set)
+ */
+smx_process_t SIMIX_rdv_get_receiver(smx_rdv_t rdv)
+{
+  return rdv->permanent_receiver;
+}
+
+/**
+ *  \brief set the receiver of the rendez vous point to allow eager sends
+ *  \param rdv The rendez-vous point
+ *  \param process The receiving process
+ */
+void SIMIX_rdv_set_receiver(smx_rdv_t rdv , smx_process_t process)
+{
+  rdv->permanent_receiver=process;
+}
+
+/**
+ *  \brief Pushes a communication action into a rendez-vous point
  *  \param rdv The rendez-vous point
- *  \param comm The communication request
+ *  \param comm The communication action
  */
 static XBT_INLINE void SIMIX_rdv_push(smx_rdv_t rdv, smx_action_t comm)
 {
@@ -105,105 +141,96 @@ static XBT_INLINE void SIMIX_rdv_push(smx_rdv_t rdv, smx_action_t comm)
 }
 
 /**
- *  \brief Remove a communication request from a rendez-vous point
+ *  \brief Removes a communication action from a rendez-vous point
  *  \param rdv The rendez-vous point
- *  \param comm The communication request
+ *  \param comm The communication action
  */
-static XBT_INLINE void SIMIX_rdv_remove(smx_rdv_t rdv, smx_action_t comm)
+XBT_INLINE void SIMIX_rdv_remove(smx_rdv_t rdv, smx_action_t comm)
 {
   xbt_fifo_remove(rdv->comm_fifo, comm);
   comm->comm.rdv = NULL;
 }
 
-smx_action_t SIMIX_comm_get_send_match(smx_rdv_t rdv, int (*match_fun)(void*, void*), void* data) {
-   return SIMIX_rdv_get_request(rdv, SIMIX_COMM_SEND, match_fun, data);
-}
-
 /**
- *  \brief Checks if there is a communication action queued in a rendez-vous matching our needs
+ *  \brief Checks if there is a communication action queued in a fifo matching our needs
  *  \param type The type of communication we are looking for (comm_send, comm_recv)
  *  \return The communication action if found, NULL otherwise
  */
-smx_action_t SIMIX_rdv_get_request(smx_rdv_t rdv, e_smx_comm_type_t type,
-                                   int (*match_fun)(void *, void *), void *data)
+smx_action_t SIMIX_fifo_get_comm(xbt_fifo_t fifo, e_smx_comm_type_t type,
+                                 int (*match_fun)(void *, void *,smx_action_t),
+                                 void *this_user_data, smx_action_t my_action)
 {
-  // FIXME rewrite this function by using SIMIX_rdv_has_send/recv_match
   smx_action_t action;
   xbt_fifo_item_t item;
-  void* req_data = NULL;
+  void* other_user_data = NULL;
 
-  xbt_fifo_foreach(rdv->comm_fifo, item, action, smx_action_t){
+  xbt_fifo_foreach(fifo, item, action, smx_action_t) {
     if (action->comm.type == SIMIX_COMM_SEND) {
-      req_data = action->comm.src_data;
+      other_user_data = action->comm.src_data;
     } else if (action->comm.type == SIMIX_COMM_RECEIVE) {
-      req_data = action->comm.dst_data;
+      other_user_data = action->comm.dst_data;
     }
-    if (action->comm.type == type && (!match_fun || match_fun(data, req_data))) {
+    if (action->comm.type == type &&
+        (!match_fun              ||              match_fun(this_user_data,  other_user_data, action)) &&
+        (!action->comm.match_fun || action->comm.match_fun(other_user_data, this_user_data,  my_action))) {
       XBT_DEBUG("Found a matching communication action %p", action);
-      xbt_fifo_remove_item(rdv->comm_fifo, item);
+      xbt_fifo_remove_item(fifo, item);
       xbt_fifo_free_item(item);
       action->comm.refcount++;
       action->comm.rdv = NULL;
       return action;
     }
     XBT_DEBUG("Sorry, communication action %p does not match our needs:"
-           " its type is %d but we are looking for a comm of type %d",
-           action, action->comm.type, type);
+              " its type is %d but we are looking for a comm of type %d (or maybe the filtering didn't match)",
+              action, (int)action->comm.type, (int)type);
   }
   XBT_DEBUG("No matching communication action found");
   return NULL;
 }
 
-/**
- *  \brief Checks if there is a send communication action
- *  queued in a rendez-vous matching our needs.
- *  \return 1 if found, 0 otherwise
- */
-int SIMIX_comm_has_send_match(smx_rdv_t rdv, int (*match_fun)(void*, void*), void* data) {
-
-  smx_action_t action;
-  xbt_fifo_item_t item;
-
-  xbt_fifo_foreach(rdv->comm_fifo, item, action, smx_action_t){
-    if (action->comm.type == SIMIX_COMM_SEND
-        && (!match_fun || match_fun(data, action->comm.src_data))) {
-      XBT_DEBUG("Found a matching communication action %p", action);
-      return 1;
-    }
-  }
-  XBT_DEBUG("No matching communication action found");
-  return 1;
-}
 
 /**
- *  \brief Checks if there is a recv communication action
- *  queued in a rendez-vous matching our needs.
- *  \return 1 if found, 0 otherwise
+ *  \brief Checks if there is a communication action queued in a fifo matching our needs, but leave it there
+ *  \param type The type of communication we are looking for (comm_send, comm_recv)
+ *  \return The communication action if found, NULL otherwise
  */
-int SIMIX_comm_has_recv_match(smx_rdv_t rdv, int (*match_fun)(void*, void*), void* data) {
-
+smx_action_t SIMIX_fifo_probe_comm(xbt_fifo_t fifo, e_smx_comm_type_t type,
+                                 int (*match_fun)(void *, void *,smx_action_t),
+                                 void *this_user_data, smx_action_t my_action)
+{
   smx_action_t action;
   xbt_fifo_item_t item;
+  void* other_user_data = NULL;
 
-  xbt_fifo_foreach(rdv->comm_fifo, item, action, smx_action_t){
-    if (action->comm.type == SIMIX_COMM_RECEIVE
-        && (!match_fun || match_fun(data, action->comm.dst_data))) {
+  xbt_fifo_foreach(fifo, item, action, smx_action_t) {
+    if (action->comm.type == SIMIX_COMM_SEND) {
+      other_user_data = action->comm.src_data;
+    } else if (action->comm.type == SIMIX_COMM_RECEIVE) {
+      other_user_data = action->comm.dst_data;
+    }
+    if (action->comm.type == type &&
+        (!match_fun              ||              match_fun(this_user_data,  other_user_data, action)) &&
+        (!action->comm.match_fun || action->comm.match_fun(other_user_data, this_user_data,  my_action))) {
       XBT_DEBUG("Found a matching communication action %p", action);
-      return 1;
+      action->comm.refcount++;
+
+      return action;
     }
+    XBT_DEBUG("Sorry, communication action %p does not match our needs:"
+              " its type is %d but we are looking for a comm of type %d (or maybe the filtering didn't match)",
+              action, (int)action->comm.type, (int)type);
   }
   XBT_DEBUG("No matching communication action found");
-  return 1;
+  return NULL;
 }
-
 /******************************************************************************/
-/*                            Comunication Actions                            */
+/*                            Communication Actions                            */
 /******************************************************************************/
 
 /**
- *  \brief Creates a new comunicate action
- *  \param type The type of request (comm_send, comm_recv)
- *  \return The new comunicate action
+ *  \brief Creates a new communicate action
+ *  \param type The direction of communication (comm_send, comm_recv)
+ *  \return The new communicate action
  */
 smx_action_t SIMIX_comm_new(e_smx_comm_type_t type)
 {
@@ -211,6 +238,7 @@ smx_action_t SIMIX_comm_new(e_smx_comm_type_t type)
 
   /* alloc structures */
   act = xbt_mallocator_get(simix_global->action_mallocator);
+
   act->type = SIMIX_ACTION_COMMUNICATE;
   act->state = SIMIX_WAITING;
 
@@ -239,24 +267,22 @@ smx_action_t SIMIX_comm_new(e_smx_comm_type_t type)
  */
 void SIMIX_comm_destroy(smx_action_t action)
 {
-  XBT_DEBUG("Destroy action %p (refcount:%d)", action, action->comm.refcount);
-
-  if (action->comm.refcount <= 0)
-    xbt_die("the refcount of comm %p is already 0 before decreasing it. "
-            "That's a bug!", action);
+  XBT_DEBUG("Destroy action %p (refcount: %d), state: %d",
+            action, action->comm.refcount, (int)action->state);
 
+  if (action->comm.refcount <= 0) {
+    xbt_backtrace_display_current();
+    xbt_die("The refcount of comm %p is already 0 before decreasing it. "
+            "That's a bug! If you didn't test and/or wait the same communication twice in your code, then the bug is SimGrid's...", action);
+  }
   action->comm.refcount--;
   if (action->comm.refcount > 0)
     return;
   XBT_DEBUG("Really free communication %p; refcount is now %d", action,
-        action->comm.refcount);
+            action->comm.refcount);
 
 #ifdef HAVE_LATENCY_BOUND_TRACKING
-    action->latency_limited = SIMIX_comm_is_latency_bounded( action ) ;
-#endif
-
-#ifdef HAVE_TRACING
-  TRACE_smx_action_destroy(action);
+  action->latency_limited = SIMIX_comm_is_latency_bounded( action ) ;
 #endif
 
   xbt_free(action->name);
@@ -265,7 +291,10 @@ void SIMIX_comm_destroy(smx_action_t action)
   if (action->comm.detached && action->state != SIMIX_DONE) {
     /* the communication has failed and was detached:
      * we have to free the buffer */
-    ((void_f_pvoid_t) action->comm.src_data)(action->comm.src_buff);
+    if (action->comm.clean_fun) {
+      action->comm.clean_fun(action->comm.src_buff);
+    }
+    action->comm.src_buff = NULL;
   }
 
   xbt_mallocator_release(simix_global->action_mallocator, action);
@@ -295,100 +324,213 @@ void SIMIX_comm_destroy_internal_actions(smx_action_t action)
 smx_action_t SIMIX_comm_isend(smx_process_t src_proc, smx_rdv_t rdv,
                               double task_size, double rate,
                               void *src_buff, size_t src_buff_size,
-                              int (*match_fun)(void *, void *), void *data,
+                              int (*match_fun)(void *, void *,smx_action_t),
+                              void (*clean_fun)(void *), // used to free the action in case of problem after a detached send
+                              void *data,
                               int detached)
 {
-  smx_action_t action;
-
-  /* Look for communication request matching our needs.
-     If it is not found then create it and push it into the rendez-vous point */
-  action = SIMIX_rdv_get_request(rdv, SIMIX_COMM_RECEIVE, match_fun, data);
+  XBT_DEBUG("send from %p\n", rdv);
+
+  /* Prepare an action describing us, so that it gets passed to the user-provided filter of other side */
+  smx_action_t this_action = SIMIX_comm_new(SIMIX_COMM_SEND);
+
+  /* Look for communication action matching our needs. We also provide a description of
+   * ourself so that the other side also gets a chance of choosing if it wants to match with us.
+   *
+   * If it is not found then push our communication into the rendez-vous point */
+  smx_action_t other_action = SIMIX_fifo_get_comm(rdv->comm_fifo, SIMIX_COMM_RECEIVE, match_fun, data, this_action);
+
+  if (!other_action) {
+    other_action = this_action;
+
+    if (rdv->permanent_receiver!=NULL){
+      //this mailbox is for small messages, which have to be sent right now
+      other_action->state = SIMIX_READY;
+      other_action->comm.dst_proc=rdv->permanent_receiver;
+      other_action->comm.refcount++;
+      other_action->comm.rdv = rdv;
+      xbt_fifo_push(rdv->done_comm_fifo,other_action);
+      other_action->comm.rdv=rdv;
+      XBT_DEBUG("pushing a message into the permanent receive fifo %p, comm %p \n", rdv, &(other_action->comm));
 
-  if (!action) {
-    action = SIMIX_comm_new(SIMIX_COMM_SEND);
-    SIMIX_rdv_push(rdv, action);
+    }else{
+      SIMIX_rdv_push(rdv, this_action);
+    }
   } else {
-    action->state = SIMIX_READY;
-    action->comm.type = SIMIX_COMM_READY;
+    XBT_DEBUG("Receive already pushed\n");
+
+    SIMIX_comm_destroy(this_action);
+    --smx_total_comms; // this creation was a pure waste
+
+    other_action->state = SIMIX_READY;
+    other_action->comm.type = SIMIX_COMM_READY;
+
   }
+  xbt_fifo_push(src_proc->comms, other_action);
 
-  /* If the communication action is detached then decrease the refcount
-   * by one, so it will be eliminated by the receivers destroy call */
+  /* if the communication action is detached then decrease the refcount
+   * by one, so it will be eliminated by the receiver's destroy call */
   if (detached) {
-    action->comm.detached = 1;
-    action->comm.refcount--;
+    other_action->comm.detached = 1;
+    other_action->comm.refcount--;
+    other_action->comm.clean_fun = clean_fun;
+  } else {
+    other_action->comm.clean_fun = NULL;
   }
 
-  /* Setup the communication request */
-  action->comm.src_proc = src_proc;
-  action->comm.task_size = task_size;
-  action->comm.rate = rate;
-  action->comm.src_buff = src_buff;
-  action->comm.src_buff_size = src_buff_size;
-  action->comm.src_data = data;
+  /* Setup the communication action */
+  other_action->comm.src_proc = src_proc;
+  other_action->comm.task_size = task_size;
+  other_action->comm.rate = rate;
+  other_action->comm.src_buff = src_buff;
+  other_action->comm.src_buff_size = src_buff_size;
+  other_action->comm.src_data = data;
 
-  if (MC_IS_ENABLED) {
-    action->state = SIMIX_RUNNING;
-    return action;
+  other_action->comm.match_fun = match_fun;
+
+  if (MC_is_active()) {
+    other_action->state = SIMIX_RUNNING;
+    return other_action;
   }
 
-  SIMIX_comm_start(action);
-  return action;
+  SIMIX_comm_start(other_action);
+  return (detached ? NULL : other_action);
 }
 
 smx_action_t SIMIX_comm_irecv(smx_process_t dst_proc, smx_rdv_t rdv,
-                      void *dst_buff, size_t *dst_buff_size,
-                      int (*match_fun)(void *, void *), void *data)
+                              void *dst_buff, size_t *dst_buff_size,
+                              int (*match_fun)(void *, void *, smx_action_t), void *data)
 {
-  smx_action_t action;
+  XBT_DEBUG("recv from %p %p\n", rdv, rdv->comm_fifo);
+  smx_action_t this_action = SIMIX_comm_new(SIMIX_COMM_RECEIVE);
+
+  smx_action_t other_action;
+  //communication already done, get it inside the fifo of completed comms
+  //permanent receive v1
+  //int already_received=0;
+  if(rdv->permanent_receiver && xbt_fifo_size(rdv->done_comm_fifo)!=0){
+
+    XBT_DEBUG("We have a comm that has probably already been received, trying to match it, to skip the communication\n");
+    //find a match in the already received fifo
+    other_action = SIMIX_fifo_get_comm(rdv->done_comm_fifo, SIMIX_COMM_SEND, match_fun, data, this_action);
+    //if not found, assume the receiver came first, register it to the mailbox in the classical way
+    if (!other_action)  {
+      XBT_DEBUG("We have messages in the permanent receive list, but not the one we are looking for, pushing request into fifo\n");
+      other_action = this_action;
+      SIMIX_rdv_push(rdv, this_action);
+    }else{
+      if(other_action->comm.surf_comm && 	SIMIX_comm_get_remains(other_action)==0.0)
+      {
+        XBT_DEBUG("comm %p has been already sent, and is finished, destroy it\n",&(other_action->comm));
+        other_action->state = SIMIX_DONE;
+        other_action->comm.type = SIMIX_COMM_DONE;
+        other_action->comm.rdv = NULL;
+        //SIMIX_comm_destroy(this_action);
+        //--smx_total_comms; // this creation was a pure waste
+        //already_received=1;
+        //other_action->comm.refcount--;
+      }/*else{
+         XBT_DEBUG("Not yet finished, we have to wait %d\n", xbt_fifo_size(rdv->comm_fifo));
+         }*/
+     // other_action->comm.refcount--;
+      SIMIX_comm_destroy(this_action);
+      --smx_total_comms; // this creation was a pure waste
+    }
+  }else{
+    /* Prepare an action describing us, so that it gets passed to the user-provided filter of other side */
+
+    /* Look for communication action matching our needs. We also provide a description of
+     * ourself so that the other side also gets a chance of choosing if it wants to match with us.
+     *
+     * If it is not found then push our communication into the rendez-vous point */
+    other_action = SIMIX_fifo_get_comm(rdv->comm_fifo, SIMIX_COMM_SEND, match_fun, data, this_action);
+
+    if (!other_action) {
+      XBT_DEBUG("Receive pushed first %d\n", xbt_fifo_size(rdv->comm_fifo));
+      other_action = this_action;
+      SIMIX_rdv_push(rdv, this_action);
+    } else {
+      SIMIX_comm_destroy(this_action);
+      --smx_total_comms; // this creation was a pure waste
+      other_action->state = SIMIX_READY;
+      other_action->comm.type = SIMIX_COMM_READY;
+   //   other_action->comm.refcount--;
+    }
+    xbt_fifo_push(dst_proc->comms, other_action);
+  }
 
-  /* Look for communication request matching our needs.
-   * If it is not found then create it and push it into the rendez-vous point
-   */
-  action = SIMIX_rdv_get_request(rdv, SIMIX_COMM_SEND, match_fun, data);
+  /* Setup communication action */
+  other_action->comm.dst_proc = dst_proc;
+  other_action->comm.dst_buff = dst_buff;
+  other_action->comm.dst_buff_size = dst_buff_size;
+  other_action->comm.dst_data = data;
 
-  if (!action) {
-    action = SIMIX_comm_new(SIMIX_COMM_RECEIVE);
-    SIMIX_rdv_push(rdv, action);
-  } else {
-    action->state = SIMIX_READY;
-    action->comm.type = SIMIX_COMM_READY;
+  other_action->comm.match_fun = match_fun;
+
+
+  /*if(already_received)//do the actual copy, because the first one after the comm didn't have all the info
+    SIMIX_comm_copy_data(other_action);*/
+
+
+  if (MC_is_active()) {
+    other_action->state = SIMIX_RUNNING;
+    return other_action;
   }
 
-  /* Setup communication request */
-  action->comm.dst_proc = dst_proc;
-  action->comm.dst_buff = dst_buff;
-  action->comm.dst_buff_size = dst_buff_size;
-  action->comm.dst_data = data;
+  SIMIX_comm_start(other_action);
+  // }
+  return other_action;
+}
 
-  if (MC_IS_ENABLED) {
-    action->state = SIMIX_RUNNING;
-    return action;
+
+smx_action_t SIMIX_comm_iprobe(smx_process_t dst_proc, smx_rdv_t rdv, int src,
+                              int tag, int (*match_fun)(void *, void *, smx_action_t), void *data)
+{
+  XBT_DEBUG("iprobe from %p %p\n", rdv, rdv->comm_fifo);
+  smx_action_t this_action = SIMIX_comm_new(SIMIX_COMM_RECEIVE);
+
+  smx_action_t other_action=NULL;
+  if(rdv->permanent_receiver && xbt_fifo_size(rdv->done_comm_fifo)!=0){
+    //find a match in the already received fifo
+      XBT_DEBUG("first try in the perm recv mailbox \n");
+
+    other_action = SIMIX_fifo_probe_comm(rdv->done_comm_fifo, SIMIX_COMM_SEND, match_fun, data, this_action);
   }
+ // }else{
+    if(!other_action){
+        XBT_DEBUG("second try in the other mailbox");
+        other_action = SIMIX_fifo_probe_comm(rdv->comm_fifo, SIMIX_COMM_SEND, match_fun, data, this_action);
+    }
+//  }
+  if(other_action)other_action->comm.refcount--;
 
-  SIMIX_comm_start(action);
-  return action;
+  SIMIX_comm_destroy(this_action);
+  --smx_total_comms;
+  return other_action;
 }
 
-void SIMIX_pre_comm_wait(smx_req_t req, smx_action_t action, double timeout, int idx)
+void SIMIX_pre_comm_wait(smx_simcall_t simcall, smx_action_t action, double timeout, int idx)
 {
-  /* the request may be a wait, a send or a recv */
+
+  /* the simcall may be a wait, a send or a recv */
   surf_action_t sleep;
 
-  /* Associate this request to the action */
-  xbt_fifo_push(action->request_list, req);
-  req->issuer->waiting_action = action;
+  /* Associate this simcall to the wait action */
+  XBT_DEBUG("SIMIX_pre_comm_wait, %p", action);
+
+  xbt_fifo_push(action->simcalls, simcall);
+  simcall->issuer->waiting_action = action;
 
-  if (MC_IS_ENABLED) {
+  if (MC_is_active()) {
     if (idx == 0) {
       action->state = SIMIX_DONE;
     } else {
-      /* If we reached this point, the wait request must have a timeout */
+      /* If we reached this point, the wait simcall must have a timeout */
       /* Otherwise it shouldn't be enabled and executed by the MC */
       if (timeout == -1)
         THROW_IMPOSSIBLE;
 
-      if (action->comm.src_proc == req->issuer)
+      if (action->comm.src_proc == simcall->issuer)
         action->state = SIMIX_SRC_TIMEOUT;
       else
         action->state = SIMIX_DST_TIMEOUT;
@@ -403,90 +545,92 @@ void SIMIX_pre_comm_wait(smx_req_t req, smx_action_t action, double timeout, int
   if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING) {
     SIMIX_comm_finish(action);
   } else { /* if (timeout >= 0) { we need a surf sleep action even when there is no timeout, otherwise surf won't tell us when the host fails */
-    sleep = surf_workstation_model->extension.workstation.sleep(req->issuer->smx_host->host, timeout);
+    sleep = surf_workstation_model->extension.workstation.sleep(simcall->issuer->smx_host->host, timeout);
     surf_workstation_model->action_data_set(sleep, action);
 
-    if (req->issuer == action->comm.src_proc)
+    if (simcall->issuer == action->comm.src_proc)
       action->comm.src_timeout = sleep;
     else
       action->comm.dst_timeout = sleep;
   }
 }
 
-void SIMIX_pre_comm_test(smx_req_t req)
+void SIMIX_pre_comm_test(smx_simcall_t simcall)
 {
-  smx_action_t action = req->comm_test.comm;
+  smx_action_t action = simcall->comm_test.comm;
 
-  if(MC_IS_ENABLED){
-    req->comm_test.result = action->comm.src_proc && action->comm.dst_proc;
-    if(req->comm_test.result){
+  if(MC_is_active()){
+    simcall->comm_test.result = action->comm.src_proc && action->comm.dst_proc;
+    if(simcall->comm_test.result){
       action->state = SIMIX_DONE;
-      xbt_fifo_push(action->request_list, req);
+      xbt_fifo_push(action->simcalls, simcall);
       SIMIX_comm_finish(action);
     }else{
-      SIMIX_request_answer(req);
+      SIMIX_simcall_answer(simcall);
     }
     return;
   }
 
-  req->comm_test.result = (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING);
-  if (req->comm_test.result) {
-    xbt_fifo_push(action->request_list, req);
+  simcall->comm_test.result = (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING);
+  if (simcall->comm_test.result) {
+    xbt_fifo_push(action->simcalls, simcall);
     SIMIX_comm_finish(action);
   } else {
-    SIMIX_request_answer(req);
+    SIMIX_simcall_answer(simcall);
   }
 }
 
-void SIMIX_pre_comm_testany(smx_req_t req, int idx)
+void SIMIX_pre_comm_testany(smx_simcall_t simcall, int idx)
 {
   unsigned int cursor;
   smx_action_t action;
-  xbt_dynar_t actions = req->comm_testany.comms;
-  req->comm_testany.result = -1;
+  xbt_dynar_t actions = simcall->comm_testany.comms;
+  simcall->comm_testany.result = -1;
 
-  if (MC_IS_ENABLED){
+  if (MC_is_active()){
     if(idx == -1){
-      SIMIX_request_answer(req);
+      SIMIX_simcall_answer(simcall);
     }else{
       action = xbt_dynar_get_as(actions, idx, smx_action_t);
-      req->comm_testany.result = idx;
-      xbt_fifo_push(action->request_list, req);
+      simcall->comm_testany.result = idx;
+      xbt_fifo_push(action->simcalls, simcall);
       action->state = SIMIX_DONE;
       SIMIX_comm_finish(action);
     }
     return;
   }
 
-  xbt_dynar_foreach(req->comm_testany.comms,cursor,action) {
+  xbt_dynar_foreach(simcall->comm_testany.comms,cursor,action) {
     if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING) {
-      req->comm_testany.result = cursor;
-      xbt_fifo_push(action->request_list, req);
+      simcall->comm_testany.result = cursor;
+      xbt_fifo_push(action->simcalls, simcall);
       SIMIX_comm_finish(action);
       return;
     }
   }
-  SIMIX_request_answer(req);
+  SIMIX_simcall_answer(simcall);
 }
 
-void SIMIX_pre_comm_waitany(smx_req_t req, int idx)
+void SIMIX_pre_comm_waitany(smx_simcall_t simcall, int idx)
 {
   smx_action_t action;
   unsigned int cursor = 0;
-  xbt_dynar_t actions = req->comm_waitany.comms;
+  xbt_dynar_t actions = simcall->comm_waitany.comms;
 
-  if (MC_IS_ENABLED){
+  if (MC_is_active()){
     action = xbt_dynar_get_as(actions, idx, smx_action_t);
-    xbt_fifo_push(action->request_list, req);
-    req->comm_waitany.result = idx;
+    xbt_fifo_push(action->simcalls, simcall);
+    simcall->comm_waitany.result = idx;
     action->state = SIMIX_DONE;
     SIMIX_comm_finish(action);
     return;
   }
 
   xbt_dynar_foreach(actions, cursor, action){
-    /* Associate this request to the action */
-    xbt_fifo_push(action->request_list, req);
+    /* associate this simcall to the the action */
+    xbt_fifo_push(action->simcalls, simcall);
+
+    /* see if the action is already finished */
     if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING){
       SIMIX_comm_finish(action);
       break;
@@ -494,47 +638,43 @@ void SIMIX_pre_comm_waitany(smx_req_t req, int idx)
   }
 }
 
-void SIMIX_waitany_req_remove_from_actions(smx_req_t req)
+void SIMIX_waitany_remove_simcall_from_actions(smx_simcall_t simcall)
 {
   smx_action_t action;
   unsigned int cursor = 0;
-  xbt_dynar_t actions = req->comm_waitany.comms;
+  xbt_dynar_t actions = simcall->comm_waitany.comms;
 
-  xbt_dynar_foreach(actions, cursor, action){
-    xbt_fifo_remove(action->request_list, req);
+  xbt_dynar_foreach(actions, cursor, action) {
+    xbt_fifo_remove(action->simcalls, simcall);
   }
 }
 
 /**
- *  \brief Start the simulation of a communication request
- *  \param action The communication action
+ *  \brief Starts the simulation of a communication action.
+ *  \param action the communication action
  */
-
 XBT_INLINE void SIMIX_comm_start(smx_action_t action)
 {
   /* If both the sender and the receiver are already there, start the communication */
   if (action->state == SIMIX_READY) {
+
     smx_host_t sender = action->comm.src_proc->smx_host;
     smx_host_t receiver = action->comm.dst_proc->smx_host;
 
     XBT_DEBUG("Starting communication %p from '%s' to '%s'", action,
-           SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
+              SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
 
     action->comm.surf_comm = surf_workstation_model->extension.workstation.
-        communicate(sender->host, receiver->host, action->comm.task_size, action->comm.rate);
+      communicate(sender->host, receiver->host, action->comm.task_size, action->comm.rate);
 
     surf_workstation_model->action_data_set(action->comm.surf_comm, action);
 
     action->state = SIMIX_RUNNING;
 
-#ifdef HAVE_TRACING
-    TRACE_smx_action_communicate(action, action->comm.src_proc);
-#endif
-
     /* If a link is failed, detect it immediately */
     if (surf_workstation_model->action_state_get(action->comm.surf_comm) == SURF_ACTION_FAILED) {
       XBT_DEBUG("Communication from '%s' to '%s' failed to start because of a link failure",
-	  SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
+                SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
       action->state = SIMIX_LINK_FAILURE;
       SIMIX_comm_destroy_internal_actions(action);
     }
@@ -544,112 +684,128 @@ XBT_INLINE void SIMIX_comm_start(smx_action_t action)
     if (SIMIX_process_is_suspended(action->comm.src_proc) ||
         SIMIX_process_is_suspended(action->comm.dst_proc)) {
       /* FIXME: check what should happen with the action state */
+
+      if (SIMIX_process_is_suspended(action->comm.src_proc))
+        XBT_DEBUG("The communication is suspended on startup because src (%s:%s) were suspended since it initiated the communication",
+                  SIMIX_host_get_name(action->comm.src_proc->smx_host), action->comm.src_proc->name);
+      else
+        XBT_DEBUG("The communication is suspended on startup because dst (%s:%s) were suspended since it initiated the communication",
+                  SIMIX_host_get_name(action->comm.dst_proc->smx_host), action->comm.dst_proc->name);
+
       surf_workstation_model->suspend(action->comm.surf_comm);
+
     }
   }
 }
 
+/**
+ * \brief Answers the SIMIX simcalls associated to a communication action.
+ * \param action a finished communication action
+ */
 void SIMIX_comm_finish(smx_action_t action)
 {
   unsigned int destroy_count = 0;
-  smx_req_t req;
+  smx_simcall_t simcall;
 
-  while ((req = xbt_fifo_shift(action->request_list))) {
+  while ((simcall = xbt_fifo_shift(action->simcalls))) {
 
-    /* If a waitany request is waiting for this action to finish, then remove
+    /* If a waitany simcall is waiting for this action to finish, then remove
        it from the other actions in the waitany list. Afterwards, get the
-       position of the actual action in the waitany request's actions dynar and
-       return it as the result of the call */
-    if (req->call == REQ_COMM_WAITANY) {
-      SIMIX_waitany_req_remove_from_actions(req);
-      if (!MC_IS_ENABLED)
-        req->comm_waitany.result = xbt_dynar_search(req->comm_waitany.comms, &action);
+       position of the actual action in the waitany dynar and
+       return it as the result of the simcall */
+    if (simcall->call == SIMCALL_COMM_WAITANY) {
+      SIMIX_waitany_remove_simcall_from_actions(simcall);
+      if (!MC_is_active())
+        simcall->comm_waitany.result = xbt_dynar_search(simcall->comm_waitany.comms, &action);
     }
 
     /* If the action is still in a rendez-vous point then remove from it */
     if (action->comm.rdv)
       SIMIX_rdv_remove(action->comm.rdv, action);
 
-    XBT_DEBUG("SIMIX_comm_finish: action state = %d", action->state);
+    XBT_DEBUG("SIMIX_comm_finish: action state = %d", (int)action->state);
 
     /* Check out for errors */
     switch (action->state) {
 
-      case SIMIX_DONE:
-        XBT_DEBUG("Communication %p complete!", action);
-        SIMIX_comm_copy_data(action);
-        break;
-
-      case SIMIX_SRC_TIMEOUT:
-        TRY {
-          THROW0(timeout_error, 0, "Communication timeouted because of sender");
-        }
-	CATCH(req->issuer->running_ctx->exception) {
-          req->issuer->doexception = 1;
-        }
-        break;
-
-      case SIMIX_DST_TIMEOUT:
-        TRY {
-          THROW0(timeout_error, 0, "Communication timeouted because of receiver");
-        }
-	CATCH(req->issuer->running_ctx->exception) {
-          req->issuer->doexception = 1;
-        }
-        break;
-
-      case SIMIX_SRC_HOST_FAILURE:
-        TRY {
-          if (req->issuer == action->comm.src_proc)
-            THROW0(host_error, 0, "Host failed");
-          else
-            THROW0(network_error, 0, "Remote peer failed");
-        }
-	CATCH(req->issuer->running_ctx->exception) {
-          req->issuer->doexception = 1;
-        }
-        break;
-
-      case SIMIX_DST_HOST_FAILURE:
-        TRY {
-          if (req->issuer == action->comm.dst_proc)
-            THROW0(host_error, 0, "Host failed");
-          else
-            THROW0(network_error, 0, "Remote peer failed");
-        }
-	CATCH(req->issuer->running_ctx->exception) {
-          req->issuer->doexception = 1;
-        }
-        break;
-
-      case SIMIX_LINK_FAILURE:
-        TRY {
-	  XBT_DEBUG("Link failure in action %p between '%s' and '%s': posting an exception to the issuer: %s (%p)",
-	      action, action->comm.src_proc->smx_host->name, action->comm.dst_proc->smx_host->name,
-	      req->issuer->name, req->issuer);
-          THROW0(network_error, 0, "Link failure");
-        }
-	CATCH(req->issuer->running_ctx->exception) {
-          req->issuer->doexception = 1;
-        }
-        break;
-
-      default:
-        THROW_IMPOSSIBLE;
+    case SIMIX_DONE:
+      XBT_DEBUG("Communication %p complete!", action);
+      SIMIX_comm_copy_data(action);
+      break;
+
+    case SIMIX_SRC_TIMEOUT:
+      SMX_EXCEPTION(simcall->issuer, timeout_error, 0,
+                    "Communication timeouted because of sender");
+      break;
+
+    case SIMIX_DST_TIMEOUT:
+      SMX_EXCEPTION(simcall->issuer, timeout_error, 0,
+                    "Communication timeouted because of receiver");
+      break;
+
+    case SIMIX_SRC_HOST_FAILURE:
+      if (simcall->issuer == action->comm.src_proc)
+        simcall->issuer->context->iwannadie = 1;
+//          SMX_EXCEPTION(simcall->issuer, host_error, 0, "Host failed");
+      else
+        SMX_EXCEPTION(simcall->issuer, network_error, 0, "Remote peer failed");
+      break;
+
+    case SIMIX_DST_HOST_FAILURE:
+      if (simcall->issuer == action->comm.dst_proc)
+        simcall->issuer->context->iwannadie = 1;
+//          SMX_EXCEPTION(simcall->issuer, host_error, 0, "Host failed");
+      else
+        SMX_EXCEPTION(simcall->issuer, network_error, 0, "Remote peer failed");
+      break;
+
+    case SIMIX_LINK_FAILURE:
+      XBT_DEBUG("Link failure in action %p between '%s' and '%s': posting an exception to the issuer: %s (%p) detached:%d",
+                action,
+                action->comm.src_proc ? action->comm.src_proc->smx_host->name : NULL,
+                action->comm.dst_proc ? action->comm.dst_proc->smx_host->name : NULL,
+                simcall->issuer->name, simcall->issuer, action->comm.detached);
+      if (action->comm.src_proc == simcall->issuer) {
+        XBT_DEBUG("I'm source");
+      } else if (action->comm.dst_proc == simcall->issuer) {
+        XBT_DEBUG("I'm dest");
+      } else {
+        XBT_DEBUG("I'm neither source nor dest");
+      }
+      SMX_EXCEPTION(simcall->issuer, network_error, 0, "Link failure");
+      break;
+
+    case SIMIX_CANCELED:
+      if (simcall->issuer == action->comm.dst_proc)
+        SMX_EXCEPTION(simcall->issuer, cancel_error, 0,
+                      "Communication canceled by the sender");
+      else
+        SMX_EXCEPTION(simcall->issuer, cancel_error, 0,
+                      "Communication canceled by the receiver");
+      break;
+
+    default:
+      xbt_die("Unexpected action state in SIMIX_comm_finish: %d", (int)action->state);
     }
 
     /* if there is an exception during a waitany or a testany, indicate the position of the failed communication */
-    if (req->issuer->doexception) {
-      if (req->call == REQ_COMM_WAITANY) {
-        req->issuer->running_ctx->exception.value = xbt_dynar_search(req->comm_waitany.comms, &action);
+    if (simcall->issuer->doexception) {
+      if (simcall->call == SIMCALL_COMM_WAITANY) {
+        simcall->issuer->running_ctx->exception.value = xbt_dynar_search(simcall->comm_waitany.comms, &action);
       }
-      else if (req->call == REQ_COMM_TESTANY) {
-        req->issuer->running_ctx->exception.value = xbt_dynar_search(req->comm_testany.comms, &action);
+      else if (simcall->call == SIMCALL_COMM_TESTANY) {
+        simcall->issuer->running_ctx->exception.value = xbt_dynar_search(simcall->comm_testany.comms, &action);
       }
     }
 
-    req->issuer->waiting_action = NULL;
-    SIMIX_request_answer(req);
+    if (surf_workstation_model->extension.
+        workstation.get_state(simcall->issuer->smx_host->host) != SURF_RESOURCE_ON) {
+      simcall->issuer->context->iwannadie = 1;
+    }
+
+    simcall->issuer->waiting_action = NULL;
+    xbt_fifo_remove(simcall->issuer->comms, action);
+    SIMIX_simcall_answer(simcall);
     destroy_count++;
   }
 
@@ -657,62 +813,82 @@ void SIMIX_comm_finish(smx_action_t action)
     SIMIX_comm_destroy(action);
 }
 
+/**
+ * \brief This function is called when a Surf communication action is finished.
+ * \param action the corresponding Simix communication
+ */
 void SIMIX_post_comm(smx_action_t action)
 {
   /* Update action state */
   if (action->comm.src_timeout &&
-     surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_DONE)
-     action->state = SIMIX_SRC_TIMEOUT;
+      surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_DONE)
+    action->state = SIMIX_SRC_TIMEOUT;
   else if (action->comm.dst_timeout &&
-          surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_DONE)
-     action->state = SIMIX_DST_TIMEOUT;
+           surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_DONE)
+    action->state = SIMIX_DST_TIMEOUT;
   else if (action->comm.src_timeout &&
-          surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_FAILED)
-     action->state = SIMIX_SRC_HOST_FAILURE;
+           surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_FAILED)
+    action->state = SIMIX_SRC_HOST_FAILURE;
   else if (action->comm.dst_timeout &&
-          surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_FAILED)
-     action->state = SIMIX_DST_HOST_FAILURE;
+           surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_FAILED)
+    action->state = SIMIX_DST_HOST_FAILURE;
   else if (action->comm.surf_comm &&
-          surf_workstation_model->action_state_get(action->comm.surf_comm) == SURF_ACTION_FAILED)
-     action->state = SIMIX_LINK_FAILURE;
-  else
+           surf_workstation_model->action_state_get(action->comm.surf_comm) == SURF_ACTION_FAILED) {
+    XBT_DEBUG("Puta madre. Surf says that the link broke");
+    action->state = SIMIX_LINK_FAILURE;
+  } else
     action->state = SIMIX_DONE;
 
-  XBT_DEBUG("SIMIX_post_comm: action state = %d", action->state);
+  XBT_DEBUG("SIMIX_post_comm: comm %p, state %d, src_proc %p, dst_proc %p, detached: %d",
+            action, (int)action->state, action->comm.src_proc, action->comm.dst_proc, action->comm.detached);
 
-  /* After this point the surf actions associated with the simix communicate
-     action are no longer needed, thus we delete them. */
+  /* destroy the surf actions associated with the Simix communication */
   SIMIX_comm_destroy_internal_actions(action);
 
-  /* If there are requests associated with the action, then answer them */
-  if (xbt_fifo_size(action->request_list))
+  /* remove the communication action from the list of pending communications
+   * of both processes (if they still exist) */
+  if (action->comm.src_proc) {
+    xbt_fifo_remove(action->comm.src_proc->comms, action);
+  }
+  if (action->comm.dst_proc) {
+    xbt_fifo_remove(action->comm.dst_proc->comms, action);
+  }
+
+  /* if there are simcalls associated with the action, then answer them */
+  if (xbt_fifo_size(action->simcalls)) {
     SIMIX_comm_finish(action);
+  }
 }
 
 void SIMIX_comm_cancel(smx_action_t action)
 {
-  /* If the action is a waiting state means that it is still in a rdv */
+  /* if the action is a waiting state means that it is still in a rdv */
   /* so remove from it and delete it */
   if (action->state == SIMIX_WAITING) {
     SIMIX_rdv_remove(action->comm.rdv, action);
-    action->state = SIMIX_FAILED;
-  } else {
-    /* When running the MC there are no surf actions */
-    if(!MC_IS_ENABLED)
-      surf_workstation_model->action_cancel(action->comm.surf_comm);
+    action->state = SIMIX_CANCELED;
+  }
+  else if (!MC_is_active() /* when running the MC there are no surf actions */
+           && (action->state == SIMIX_READY || action->state == SIMIX_RUNNING)) {
+
+    surf_workstation_model->action_cancel(action->comm.surf_comm);
   }
 }
 
 void SIMIX_comm_suspend(smx_action_t action)
 {
   /*FIXME: shall we suspend also the timeout actions? */
-  surf_workstation_model->suspend(action->comm.surf_comm);
+  if (action->comm.surf_comm)
+    surf_workstation_model->suspend(action->comm.surf_comm);
+  /* in the other case, the action will be suspended on creation, in SIMIX_comm_start() */
 }
 
 void SIMIX_comm_resume(smx_action_t action)
 {
   /*FIXME: check what happen with the timeouts */
-  surf_workstation_model->resume(action->comm.surf_comm);
+  if (action->comm.surf_comm)
+    surf_workstation_model->resume(action->comm.surf_comm);
+  /* in the other case, the action were not really suspended yet, see SIMIX_comm_suspend() and SIMIX_comm_start() */
 }
 
 
@@ -726,20 +902,24 @@ double SIMIX_comm_get_remains(smx_action_t action)
 {
   double remains;
 
+  if(!action){
+    return 0;
+  }
+
   switch (action->state) {
 
-    case SIMIX_RUNNING:
-      remains = surf_workstation_model->get_remains(action->comm.surf_comm);
-      break;
+  case SIMIX_RUNNING:
+    remains = surf_workstation_model->get_remains(action->comm.surf_comm);
+    break;
 
-    case SIMIX_WAITING:
-    case SIMIX_READY:
-      remains = 0; /*FIXME: check what should be returned */
-      break;
+  case SIMIX_WAITING:
+  case SIMIX_READY:
+    remains = 0; /*FIXME: check what should be returned */
+    break;
 
-    default:
-      remains = 0; /*FIXME: is this correct? */
-      break;
+  default:
+    remains = 0; /*FIXME: is this correct? */
+    break;
   }
   return remains;
 }
@@ -786,10 +966,13 @@ smx_process_t SIMIX_comm_get_dst_proc(smx_action_t action)
  */
 XBT_INLINE int SIMIX_comm_is_latency_bounded(smx_action_t action)
 {
+  if(!action){
+    return 0;
+  }
   if (action->comm.surf_comm){
-      XBT_DEBUG("Getting latency limited for surf_action (%p)", action->comm.surf_comm);
-      action->latency_limited = surf_workstation_model->get_latency_limited(action->comm.surf_comm);
-      XBT_DEBUG("Action limited is %d", action->latency_limited);
+    XBT_DEBUG("Getting latency limited for surf_action (%p)", action->comm.surf_comm);
+    action->latency_limited = surf_workstation_model->get_latency_limited(action->comm.surf_comm);
+    XBT_DEBUG("Action limited is %d", action->latency_limited);
   }
   return action->latency_limited;
 }
@@ -798,27 +981,33 @@ XBT_INLINE int SIMIX_comm_is_latency_bounded(smx_action_t action)
 /******************************************************************************/
 /*                    SIMIX_comm_copy_data callbacks                       */
 /******************************************************************************/
-static void (*SIMIX_comm_copy_data_callback) (smx_action_t, size_t) =
-    &SIMIX_comm_copy_pointer_callback;
+static void (*SIMIX_comm_copy_data_callback) (smx_action_t, void*, size_t) =
+  &SIMIX_comm_copy_pointer_callback;
 
 void
-SIMIX_comm_set_copy_data_callback(void (*callback) (smx_action_t, size_t))
+SIMIX_comm_set_copy_data_callback(void (*callback) (smx_action_t, void*, size_t))
 {
   SIMIX_comm_copy_data_callback = callback;
 }
 
-void SIMIX_comm_copy_pointer_callback(smx_action_t comm, size_t buff_size)
+void SIMIX_comm_copy_pointer_callback(smx_action_t comm, void* buff, size_t buff_size)
 {
-  xbt_assert1((buff_size == sizeof(void *)),
-              "Cannot copy %zu bytes: must be sizeof(void*)", buff_size);
-  *(void **) (comm->comm.dst_buff) = comm->comm.src_buff;
+  xbt_assert((buff_size == sizeof(void *)),
+             "Cannot copy %zu bytes: must be sizeof(void*)", buff_size);
+  *(void **) (comm->comm.dst_buff) = buff;
 }
 
-void SIMIX_comm_copy_buffer_callback(smx_action_t comm, size_t buff_size)
+void SIMIX_comm_copy_buffer_callback(smx_action_t comm, void* buff, size_t buff_size)
 {
-  memcpy(comm->comm.dst_buff, comm->comm.src_buff, buff_size);
+  XBT_DEBUG("Copy the data over");
+  memcpy(comm->comm.dst_buff, buff, buff_size);
+  if (comm->comm.detached) { // if this is a detached send, the source buffer was duplicated by SMPI sender to make the original buffer available to the application ASAP
+    xbt_free(buff);
+    comm->comm.src_buff = NULL;
+  }
 }
 
+
 /**
  *  \brief Copy the communication data from the sender's buffer to the receiver's one
  *  \param comm The communication
@@ -827,13 +1016,15 @@ void SIMIX_comm_copy_data(smx_action_t comm)
 {
   size_t buff_size = comm->comm.src_buff_size;
   /* If there is no data to be copy then return */
-  if (!comm->comm.src_buff || !comm->comm.dst_buff || comm->comm.copied == 1)
+  if (!comm->comm.src_buff || !comm->comm.dst_buff || comm->comm.copied)
     return;
 
   XBT_DEBUG("Copying comm %p data from %s (%p) -> %s (%p) (%zu bytes)",
-         comm,
-         comm->comm.src_proc->smx_host->name, comm->comm.src_buff,
-         comm->comm.dst_proc->smx_host->name, comm->comm.dst_buff, buff_size);
+            comm,
+            comm->comm.src_proc ? comm->comm.src_proc->smx_host->name : "a finished process",
+            comm->comm.src_buff,
+            comm->comm.dst_proc ? comm->comm.dst_proc->smx_host->name : "a finished process",
+            comm->comm.dst_buff, buff_size);
 
   /* Copy at most dst_buff_size bytes of the message to receiver's buffer */
   if (comm->comm.dst_buff_size)
@@ -843,10 +1034,8 @@ void SIMIX_comm_copy_data(smx_action_t comm)
   if (comm->comm.dst_buff_size)
     *comm->comm.dst_buff_size = buff_size;
 
-  if (buff_size == 0)
-    return;
-
-  (*SIMIX_comm_copy_data_callback) (comm, buff_size);
+  if (buff_size > 0)
+    SIMIX_comm_copy_data_callback (comm, comm->comm.src_buff, buff_size);
 
   /* Set the copied flag so we copy data only once */
   /* (this function might be called from both communication ends) */