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fix raw contextes for supernovae and for parallel execution
[simgrid.git] / src / simix / smx_network.c
1 /* Copyright (c) 2009, 2010. The SimGrid Team.
2  * All rights reserved.                                                     */
3
4 /* This program is free software; you can redistribute it and/or modify it
5  * under the terms of the license (GNU LGPL) which comes with this package. */
6
7 #include "private.h"
8 #include "xbt/log.h"
9 #include "mc/mc.h"
10 #include "xbt/dict.h"
11
12 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_network, simix,
13                                 "Logging specific to SIMIX (network)");
14
15 static xbt_dict_t rdv_points = NULL;
16
17 static XBT_INLINE void SIMIX_comm_start(smx_action_t action);
18 static void SIMIX_comm_finish(smx_action_t action);
19 static void SIMIX_waitany_req_remove_from_actions(smx_req_t req);
20 static void SIMIX_comm_copy_data(smx_action_t comm);
21 static smx_action_t SIMIX_comm_new(e_smx_comm_type_t type);
22 static XBT_INLINE void SIMIX_comm_wait_for_completion(smx_action_t comm,
23                                                       double timeout);
24 static XBT_INLINE void SIMIX_rdv_push(smx_rdv_t rdv, smx_action_t comm);
25 static XBT_INLINE void SIMIX_rdv_remove(smx_rdv_t rdv, smx_action_t comm);
26 static smx_action_t SIMIX_rdv_get_request(smx_rdv_t rdv, e_smx_comm_type_t type,
27                                                                                   int (*match_fun)(void *, void *), void *);
28 static void SIMIX_rdv_free(void *data);
29
30 void SIMIX_network_init(void)
31 {
32   rdv_points = xbt_dict_new();
33 }
34
35 void SIMIX_network_exit(void)
36 {
37   xbt_dict_free(&rdv_points);
38 }
39
40 /******************************************************************************/
41 /*                           Rendez-Vous Points                               */
42 /******************************************************************************/
43
44 smx_rdv_t SIMIX_rdv_create(const char *name)
45 {
46   /* two processes may have pushed the same rdv_create request at the same time */
47   smx_rdv_t rdv = name ? xbt_dict_get_or_null(rdv_points, name) : NULL;
48
49   if (!rdv) {
50     rdv = xbt_new0(s_smx_rvpoint_t, 1);
51     rdv->name = name ? xbt_strdup(name) : NULL;
52     rdv->comm_fifo = xbt_fifo_new();
53
54     if (name)
55       xbt_dict_set(rdv_points, name, rdv, SIMIX_rdv_free);
56   }
57   return rdv;
58 }
59
60 void SIMIX_rdv_destroy(smx_rdv_t rdv)
61 {
62   if (rdv->name)
63     xbt_dict_remove(rdv_points, rdv->name); 
64 }
65
66 void SIMIX_rdv_free(void *data)
67 {
68   smx_rdv_t rdv = (smx_rdv_t) data;
69   if (rdv->name)
70     xbt_free(rdv->name);
71   xbt_fifo_free(rdv->comm_fifo);
72   xbt_free(rdv);  
73 }
74
75 smx_rdv_t SIMIX_rdv_get_by_name(const char *name)
76 {
77   return xbt_dict_get_or_null(rdv_points, name);
78 }
79
80 int SIMIX_rdv_comm_count_by_host(smx_rdv_t rdv, smx_host_t host)
81 {
82   smx_action_t comm = NULL;
83   xbt_fifo_item_t item = NULL;
84   int count = 0;
85
86   xbt_fifo_foreach(rdv->comm_fifo, item, comm, smx_action_t) {
87     if (comm->comm.src_proc->smx_host == host)
88       count++;
89   }
90
91   return count;
92 }
93
94 smx_action_t SIMIX_rdv_get_head(smx_rdv_t rdv)
95 {
96   return xbt_fifo_get_item_content(xbt_fifo_get_first_item(rdv->comm_fifo));
97 }
98
99 /**
100  *  \brief Push a communication request into a rendez-vous point
101  *  \param rdv The rendez-vous point
102  *  \param comm The communication request
103  */
104 static XBT_INLINE void SIMIX_rdv_push(smx_rdv_t rdv, smx_action_t comm)
105 {
106   xbt_fifo_push(rdv->comm_fifo, comm);
107   comm->comm.rdv = rdv;
108 }
109
110 /**
111  *  \brief Remove a communication request from a rendez-vous point
112  *  \param rdv The rendez-vous point
113  *  \param comm The communication request
114  */
115 static XBT_INLINE void SIMIX_rdv_remove(smx_rdv_t rdv, smx_action_t comm)
116 {
117   xbt_fifo_remove(rdv->comm_fifo, comm);
118   comm->comm.rdv = NULL;
119 }
120
121 /**
122  *  \brief Checks if there is a communication request queued in a rendez-vous matching our needs
123  *  \param type The type of communication we are looking for (comm_send, comm_recv)
124  *  \return The communication request if found, NULL otherwise
125  */
126 smx_action_t SIMIX_rdv_get_request(smx_rdv_t rdv, e_smx_comm_type_t type,
127                                                                    int (*match_fun)(void *, void *), void *data)
128 {
129   smx_action_t req;
130   xbt_fifo_item_t item;
131   void* req_data = NULL;
132
133   xbt_fifo_foreach(rdv->comm_fifo, item, req, smx_action_t){
134     if(req->comm.type == SIMIX_COMM_SEND) {
135       req_data = req->comm.src_data;
136     } else if(req->comm.type == SIMIX_COMM_RECEIVE) {
137       req_data = req->comm.dst_data;
138     }
139          if(req->comm.type == type && (!match_fun || match_fun(data, req_data))) {
140            xbt_fifo_remove_item(rdv->comm_fifo, item);
141            req->comm.refcount++;
142            req->comm.rdv = NULL;
143            return req;
144          }
145   }
146   DEBUG0("Communication request not found");
147   return NULL;
148 }
149
150 /******************************************************************************/
151 /*                            Comunication Actions                            */
152 /******************************************************************************/
153
154 /**
155  *  \brief Creates a new comunicate action
156  *  \param type The type of request (comm_send, comm_recv)
157  *  \return The new comunicate action
158  */
159 smx_action_t SIMIX_comm_new(e_smx_comm_type_t type)
160 {
161   smx_action_t act;
162
163   /* alloc structures */
164   act = xbt_new0(s_smx_action_t, 1);
165   act->type = SIMIX_ACTION_COMMUNICATE;
166   act->state = SIMIX_WAITING;
167   act->request_list = xbt_fifo_new();
168
169   /* set communication */
170   act->comm.type = type;
171   act->comm.refcount = 1;
172
173 #ifdef HAVE_TRACING
174   act->category = NULL;
175 #endif
176
177   DEBUG1("Create communicate action %p", act);
178
179   return act;
180 }
181
182 /**
183  *  \brief Destroy a communicate action
184  *  \param action The communicate action to be destroyed
185  */
186 void SIMIX_comm_destroy(smx_action_t action)
187 {
188   DEBUG1("Destroy action %p", action);
189
190   if (action->comm.refcount <= 0)
191     xbt_die(bprintf("the refcount of comm %p is already 0 before decreasing it. That's a bug!",action));
192
193 #ifdef HAVE_LATENCY_BOUND_TRACKING
194   //save is latency limited flag to use afterwards
195   if (action->comm.surf_comm) {
196     DEBUG2("adding key %p with latency limited value %d to the dict", action,
197            SIMIX_comm_is_latency_bounded(action));
198     xbt_dicti_set(simix_global->latency_limited_dict, (uintptr_t) action,
199                   SIMIX_comm_is_latency_bounded(action));
200   }
201 #endif
202
203   action->comm.refcount--;
204   if (action->comm.refcount > 0)
205     return;
206   VERB2("Really free communication %p; refcount is now %d", action,
207         action->comm.refcount);
208
209 #ifdef HAVE_TRACING
210   TRACE_smx_action_destroy(action);
211 #endif
212
213   if (action->name)
214     xbt_free(action->name);
215
216   xbt_fifo_free(action->request_list);
217
218   SIMIX_comm_destroy_internal_actions(action);
219
220   xbt_free(action);
221 }
222
223 void SIMIX_comm_destroy_internal_actions(smx_action_t action)
224 {
225   if (action->comm.surf_comm){
226     action->comm.surf_comm->model_type->action_unref(action->comm.surf_comm);
227     action->comm.surf_comm = NULL;
228   }
229
230   if (action->comm.src_timeout){
231     action->comm.src_timeout->model_type->action_unref(action->comm.src_timeout);
232     action->comm.src_timeout = NULL;
233   }
234
235   if (action->comm.dst_timeout){
236     action->comm.dst_timeout->model_type->action_unref(action->comm.dst_timeout);
237     action->comm.dst_timeout = NULL;
238   }
239 }
240
241 smx_action_t SIMIX_comm_isend(smx_process_t src_proc, smx_rdv_t rdv,
242                               double task_size, double rate,
243                               void *src_buff, size_t src_buff_size,
244                               int (*match_fun)(void *, void *), void *data)
245 {
246   smx_action_t action;
247
248   /* Look for communication request matching our needs.
249      If it is not found then create it and push it into the rendez-vous point */
250   action = SIMIX_rdv_get_request(rdv, SIMIX_COMM_RECEIVE, match_fun, data);
251
252   if (!action) {
253     action = SIMIX_comm_new(SIMIX_COMM_SEND);
254     SIMIX_rdv_push(rdv, action);
255   } else {
256     action->state = SIMIX_READY;
257     action->comm.type = SIMIX_COMM_READY;
258   }
259
260   /* Setup the communication request */
261   action->comm.src_proc = src_proc;
262   action->comm.task_size = task_size;
263   action->comm.rate = rate;
264   action->comm.src_buff = src_buff;
265   action->comm.src_buff_size = src_buff_size;
266   action->comm.src_data = data;
267
268   if (MC_IS_ENABLED) {
269     action->state = SIMIX_RUNNING;
270     return action;
271   }
272
273   SIMIX_comm_start(action);
274   return action;
275 }
276
277 smx_action_t SIMIX_comm_irecv(smx_process_t dst_proc, smx_rdv_t rdv,
278                       void *dst_buff, size_t *dst_buff_size,
279                       int (*match_fun)(void *, void *), void *data)
280 {
281   smx_action_t action;
282
283   /* Look for communication request matching our needs.
284    * If it is not found then create it and push it into the rendez-vous point
285    */
286   action = SIMIX_rdv_get_request(rdv, SIMIX_COMM_SEND, match_fun, data);
287
288   if (!action) {
289     action = SIMIX_comm_new(SIMIX_COMM_RECEIVE);
290     SIMIX_rdv_push(rdv, action);
291   } else {
292     action->state = SIMIX_READY;
293     action->comm.type = SIMIX_COMM_READY;
294   }
295
296   /* Setup communication request */
297   action->comm.dst_proc = dst_proc;
298   action->comm.dst_buff = dst_buff;
299   action->comm.dst_buff_size = dst_buff_size;
300   action->comm.dst_data = data;
301
302   if (MC_IS_ENABLED) {
303     action->state = SIMIX_RUNNING;
304     return action;
305   }
306
307   SIMIX_comm_start(action);
308   return action;
309 }
310
311 void SIMIX_pre_comm_wait(smx_req_t req)
312 {
313   smx_action_t action = req->comm_wait.comm;
314   double timeout = req->comm_wait.timeout;
315   surf_action_t sleep;
316
317   /* Associate this request to the action */
318   xbt_fifo_push(action->request_list, req);
319   req->issuer->waiting_action = action;
320
321   if (MC_IS_ENABLED){
322     action->state = SIMIX_DONE;
323     SIMIX_comm_finish(action);
324     return;
325   }
326
327   /* If the action has already finish perform the error handling, */
328   /* otherwise set up a waiting timeout on the right side         */
329   if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING) {
330     SIMIX_comm_finish(action);
331   } 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 */
332     sleep = surf_workstation_model->extension.workstation.sleep(req->issuer->smx_host->host, timeout);
333     surf_workstation_model->action_data_set(sleep, action);
334
335     if (req->issuer == action->comm.src_proc)
336       action->comm.src_timeout = sleep;
337     else
338       action->comm.dst_timeout = sleep;
339   }
340 }
341
342 void SIMIX_pre_comm_test(smx_req_t req)
343 {
344   smx_action_t action = req->comm_test.comm;
345   req->comm_test.result = (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING);
346
347   if (req->comm_test.result) {
348     xbt_fifo_push(action->request_list, req);
349     SIMIX_comm_finish(action);
350   }
351   else {
352     SIMIX_request_answer(req);
353   }
354 }
355
356 void SIMIX_pre_comm_testany(smx_req_t req)
357 {
358   unsigned int cursor;
359   smx_action_t action;
360   req->comm_testany.result = -1;
361   xbt_dynar_foreach(req->comm_testany.comms,cursor,action) {
362     if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING) {
363       req->comm_testany.result = cursor;
364       xbt_fifo_push(action->request_list, req);
365       SIMIX_comm_finish(action);
366       break;
367     }
368   }
369   SIMIX_request_answer(req);
370 }
371
372 void SIMIX_pre_comm_waitany(smx_req_t req)
373 {
374   smx_action_t action;
375   unsigned int cursor = 0;
376   xbt_dynar_t actions = req->comm_waitany.comms;
377   xbt_dynar_foreach(actions, cursor, action){
378     /* Associate this request to the action */
379     xbt_fifo_push(action->request_list, req);
380     if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING){
381       SIMIX_comm_finish(action);
382       break;
383     }
384   }
385 }
386
387 void SIMIX_waitany_req_remove_from_actions(smx_req_t req)
388 {
389   smx_action_t action;
390   unsigned int cursor = 0;
391   xbt_dynar_t actions = req->comm_waitany.comms;
392
393   xbt_dynar_foreach(actions, cursor, action){
394     xbt_fifo_remove(action->request_list, req);
395   }
396 }
397
398 /**
399  *  \brief Start the simulation of a communication request
400  *  \param action The communication action
401  */
402 static XBT_INLINE void SIMIX_comm_start(smx_action_t action)
403 {
404   /* If both the sender and the receiver are already there, start the communication */
405   if (action->state == SIMIX_READY) {
406     smx_host_t sender = action->comm.src_proc->smx_host;
407     smx_host_t receiver = action->comm.dst_proc->smx_host;
408
409     DEBUG3("Starting communication %p from '%s' to '%s'", action,
410            SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
411
412     action->comm.surf_comm = surf_workstation_model->extension.workstation.
413         communicate(sender->host, receiver->host, action->comm.task_size, action->comm.rate);
414
415     surf_workstation_model->action_data_set(action->comm.surf_comm, action);
416
417     action->state = SIMIX_RUNNING;
418
419 #ifdef HAVE_TRACING
420     TRACE_smx_action_communicate(action, action->comm.src_proc);
421 #endif
422
423     /* If a link is failed, detect it immediately */
424     if (surf_workstation_model->action_state_get(action->comm.surf_comm) == SURF_ACTION_FAILED) {
425       DEBUG2("Communication from '%s' to '%s' failed to start because of a link failure",
426           SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
427       action->state = SIMIX_LINK_FAILURE;
428       SIMIX_comm_destroy_internal_actions(action);
429     }
430
431     /* If any of the process is suspend, create the action but stop its execution,
432        it will be restarted when the sender process resume */
433     if (SIMIX_process_is_suspended(action->comm.src_proc) ||
434         SIMIX_process_is_suspended(action->comm.dst_proc)) {
435       /* FIXME: check what should happen with the action state */
436       surf_workstation_model->suspend(action->comm.surf_comm);
437     }
438   }
439 }
440
441 void SIMIX_comm_finish(smx_action_t action)
442 {
443   smx_req_t req;
444
445   while ((req = xbt_fifo_shift(action->request_list))) {
446
447     /* If a waitany request is waiting for this action to finish, then remove
448        it from the other actions in the waitany list. Afterwards, get the
449        position of the actual action in the waitany request's actions dynar and
450        return it as the result of the call */
451     if (req->call == REQ_COMM_WAITANY) {
452       SIMIX_waitany_req_remove_from_actions(req);
453       req->comm_waitany.result = xbt_dynar_search(req->comm_waitany.comms, &action);
454     }
455
456     /* If the action is still in a rendez-vous point then remove from it */
457     if (action->comm.rdv)
458       SIMIX_rdv_remove(action->comm.rdv, action);
459
460     DEBUG1("SIMIX_comm_finish: action state = %d", action->state);
461
462     /* Check out for errors */
463     switch (action->state) {
464
465       case SIMIX_DONE:
466         DEBUG1("Communication %p complete!", action);
467         SIMIX_comm_copy_data(action);
468         break;
469
470       case SIMIX_SRC_TIMEOUT:
471         TRY {
472           THROW0(timeout_error, 0, "Communication timeouted because of sender");
473         }
474         CATCH(req->issuer->running_ctx->exception) {
475           req->issuer->doexception = 1;
476         }
477         break;
478
479       case SIMIX_DST_TIMEOUT:
480         TRY {
481           THROW0(timeout_error, 0, "Communication timeouted because of receiver");
482         }
483         CATCH(req->issuer->running_ctx->exception) {
484           req->issuer->doexception = 1;
485         }
486         break;
487
488       case SIMIX_SRC_HOST_FAILURE:
489         TRY {
490           if (req->issuer == action->comm.src_proc)
491             THROW0(host_error, 0, "Host failed");
492           else
493             THROW0(network_error, 0, "Remote peer failed");
494         }
495         CATCH(req->issuer->running_ctx->exception) {
496           req->issuer->doexception = 1;
497         }
498         break;
499
500       case SIMIX_DST_HOST_FAILURE:
501         TRY {
502           if (req->issuer == action->comm.dst_proc)
503             THROW0(host_error, 0, "Host failed");
504           else
505             THROW0(network_error, 0, "Remote peer failed");
506         }
507         CATCH(req->issuer->running_ctx->exception) {
508           req->issuer->doexception = 1;
509         }
510         break;
511
512       case SIMIX_LINK_FAILURE:
513         TRY {
514           DEBUG5("Link failure in action %p between '%s' and '%s': posting an exception to the issuer: %s (%p)",
515               action, action->comm.src_proc->smx_host->name, action->comm.dst_proc->smx_host->name,
516               req->issuer->name, req->issuer);
517           THROW0(network_error, 0, "Link failure");
518         }
519         CATCH(req->issuer->running_ctx->exception) {
520           req->issuer->doexception = 1;
521         }
522         break;
523
524       default:
525         THROW_IMPOSSIBLE;
526     }
527     req->issuer->waiting_action = NULL;
528     SIMIX_request_answer(req);
529   }
530 }
531
532 void SIMIX_post_comm(smx_action_t action)
533 {
534   /* Update action state */
535   if (action->comm.src_timeout &&
536      surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_DONE)
537      action->state = SIMIX_SRC_TIMEOUT;
538   else if (action->comm.dst_timeout &&
539           surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_DONE)
540      action->state = SIMIX_DST_TIMEOUT;
541   else if (action->comm.src_timeout &&
542           surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_FAILED)
543      action->state = SIMIX_SRC_HOST_FAILURE;
544   else if (action->comm.dst_timeout &&
545           surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_FAILED)
546      action->state = SIMIX_DST_HOST_FAILURE;
547   else if (action->comm.surf_comm &&
548           surf_workstation_model->action_state_get(action->comm.surf_comm) == SURF_ACTION_FAILED)
549      action->state = SIMIX_LINK_FAILURE;
550   else
551     action->state = SIMIX_DONE;
552
553   DEBUG1("SIMIX_post_comm: action state = %d", action->state);
554
555   /* After this point the surf actions associated with the simix communicate
556      action are no longer needed, thus we delete them. */
557   SIMIX_comm_destroy_internal_actions(action);
558
559   /* If there are requests associated with the action, then answer them */
560   if (xbt_fifo_size(action->request_list))
561     SIMIX_comm_finish(action);
562 }
563
564 void SIMIX_comm_cancel(smx_action_t action)
565 {
566   /* If the action is a waiting state means that it is still in a rdv */
567   /* so remove from it and delete it */
568   if (action->state == SIMIX_WAITING) {
569     SIMIX_rdv_remove(action->comm.rdv, action);
570     action->state = SIMIX_FAILED;
571   } else {
572     surf_workstation_model->action_cancel(action->comm.surf_comm);
573   }
574 }
575
576 void SIMIX_comm_suspend(smx_action_t action)
577 {
578   /*FIXME: shall we suspend also the timeout actions? */
579   surf_workstation_model->suspend(action->comm.surf_comm);
580 }
581
582 void SIMIX_comm_resume(smx_action_t action)
583 {
584   /*FIXME: check what happen with the timeouts */
585   surf_workstation_model->resume(action->comm.surf_comm);
586 }
587
588
589 /************* Action Getters **************/
590
591 /**
592  *  \brief get the amount remaining from the communication
593  *  \param action The communication
594  */
595 double SIMIX_comm_get_remains(smx_action_t action)
596 {
597   double remains;
598
599   switch (action->state) {
600
601     case SIMIX_RUNNING:
602       remains = surf_workstation_model->get_remains(action->comm.surf_comm);
603       break;
604
605     case SIMIX_WAITING:
606     case SIMIX_READY:
607       remains = 0; /*FIXME: check what should be returned */
608       break;
609
610     default:
611       remains = 0; /*FIXME: is this correct? */
612       break;
613   }
614   return remains;
615 }
616
617 e_smx_state_t SIMIX_comm_get_state(smx_action_t action)
618 {
619   return action->state;
620 }
621
622 /**
623  *  \brief Return the user data associated to the sender of the communication
624  *  \param action The communication
625  *  \return the user data
626  */
627 void* SIMIX_comm_get_src_data(smx_action_t action)
628 {
629   return action->comm.src_data;
630 }
631
632 /**
633  *  \brief Return the user data associated to the receiver of the communication
634  *  \param action The communication
635  *  \return the user data
636  */
637 void* SIMIX_comm_get_dst_data(smx_action_t action)
638 {
639   return action->comm.dst_data;
640 }
641
642 void* SIMIX_comm_get_src_buff(smx_action_t action)
643 {
644   return action->comm.src_buff;
645 }
646
647 void* SIMIX_comm_get_dst_buff(smx_action_t action)
648 {
649   return action->comm.dst_buff;
650 }
651
652 size_t SIMIX_comm_get_src_buff_size(smx_action_t action)
653 {
654   return action->comm.src_buff_size;
655 }
656
657 size_t SIMIX_comm_get_dst_buff_size(smx_action_t action)
658 {
659   size_t buff_size;
660
661   if (action->comm.dst_buff_size)
662     buff_size = *(action->comm.dst_buff_size);
663   else
664     buff_size = 0;
665
666   return buff_size;
667 }
668
669 smx_process_t SIMIX_comm_get_src_proc(smx_action_t action)
670 {
671   return action->comm.src_proc;
672 }
673
674 smx_process_t SIMIX_comm_get_dst_proc(smx_action_t action)
675 {
676   return action->comm.dst_proc;
677 }
678
679 #ifdef HAVE_LATENCY_BOUND_TRACKING
680 /**
681  *  \brief verify if communication is latency bounded
682  *  \param comm The communication
683  */
684 XBT_INLINE int SIMIX_comm_is_latency_bounded(smx_action_t action)
685 {
686   //try to find comm on the list of finished flows
687   uintptr_t key = 0;
688   uintptr_t data = 0;
689   xbt_dict_cursor_t cursor;
690   xbt_dict_foreach(simix_global->latency_limited_dict, cursor, key, data) {
691     DEBUG2("comparing key=%p with comm=%p", (void *) key, (void *) action);
692     if ((void *) action == (void *) key) {
693       DEBUG2("key %p found, return value latency limited value %d",
694              (void *) key, (int) data);
695       xbt_dict_cursor_free(&cursor);
696       return (int) data;
697     }
698   }
699
700   return surf_workstation_model->get_latency_limited(action->comm.surf_comm);
701 }
702 #endif
703
704 /******************************************************************************/
705 /*                    SIMIX_comm_copy_data callbacks                       */
706 /******************************************************************************/
707 static void (*SIMIX_comm_copy_data_callback) (smx_action_t, size_t) =
708     &SIMIX_comm_copy_pointer_callback;
709
710 void
711 SIMIX_comm_set_copy_data_callback(void (*callback) (smx_action_t, size_t))
712 {
713   SIMIX_comm_copy_data_callback = callback;
714 }
715
716 void SIMIX_comm_copy_pointer_callback(smx_action_t comm, size_t buff_size)
717 {
718   xbt_assert1((buff_size == sizeof(void *)),
719               "Cannot copy %zu bytes: must be sizeof(void*)", buff_size);
720   *(void **) (comm->comm.dst_buff) = comm->comm.src_buff;
721 }
722
723 void SIMIX_comm_copy_buffer_callback(smx_action_t comm, size_t buff_size)
724 {
725   memcpy(comm->comm.dst_buff, comm->comm.src_buff, buff_size);
726 }
727
728 /**
729  *  \brief Copy the communication data from the sender's buffer to the receiver's one
730  *  \param comm The communication
731  */
732 void SIMIX_comm_copy_data(smx_action_t comm)
733 {
734   size_t buff_size = comm->comm.src_buff_size;
735   /* If there is no data to be copy then return */
736   if (!comm->comm.src_buff || !comm->comm.dst_buff || comm->comm.copied == 1)
737     return;
738
739   DEBUG6("Copying comm %p data from %s (%p) -> %s (%p) (%zu bytes)",
740          comm,
741          comm->comm.src_proc->smx_host->name, comm->comm.src_buff,
742          comm->comm.dst_proc->smx_host->name, comm->comm.dst_buff, buff_size);
743
744   /* Copy at most dst_buff_size bytes of the message to receiver's buffer */
745   if (comm->comm.dst_buff_size)
746     buff_size = MIN(buff_size, *(comm->comm.dst_buff_size));
747
748   /* Update the receiver's buffer size to the copied amount */
749   if (comm->comm.dst_buff_size)
750     *comm->comm.dst_buff_size = buff_size;
751
752   if (buff_size == 0)
753     return;
754
755   (*SIMIX_comm_copy_data_callback) (comm, buff_size);
756
757   /* Set the copied flag so we copy data only once */
758   /* (this function might be called from both communication ends) */
759   comm->comm.copied = 1;
760 }