2 /* Copyright (c) 2010. The SimGrid Team.
3 * All rights reserved. */
5 /* This program is free software; you can redistribute it and/or modify it
6 * under the terms of the license (GNU LGPL) which comes with this package. */
11 #include "xbt/asserts.h"
12 #include "mc/modelchecker.h"
13 XBT_LOG_NEW_DEFAULT_CATEGORY(msg_chord,
14 "Messages specific for this msg example");
18 #define MAILBOX_NAME_SIZE 10
20 static int nb_bits = 24;
21 static int nb_keys = 0;
22 static int timeout = 50;
23 static int max_simulation_time = 1000;
24 static int periodic_stabilize_delay = 20;
25 static int periodic_fix_fingers_delay = 120;
26 static int periodic_check_predecessor_delay = 120;
27 static int periodic_lookup_delay = 10;
32 typedef struct finger {
34 char mailbox[MAILBOX_NAME_SIZE]; // string representation of the id
35 } s_finger_t, *finger_t;
42 char mailbox[MAILBOX_NAME_SIZE]; // my mailbox name (string representation of the id)
43 s_finger_t *fingers; // finger table, of size nb_bits (fingers[0] is my successor)
44 int pred_id; // predecessor id
45 char pred_mailbox[MAILBOX_NAME_SIZE]; // predecessor's mailbox name
46 int next_finger_to_fix; // index of the next finger to fix in fix_fingers()
47 msg_comm_t comm_receive; // current communication to receive
48 xbt_dynar_t comms; // current communications being sent
49 double last_change_date; // last time I changed a finger or my predecessor
53 * Types of tasks exchanged between nodes.
57 TASK_FIND_SUCCESSOR_ANSWER,
59 TASK_GET_PREDECESSOR_ANSWER,
61 TASK_SUCCESSOR_LEAVING,
62 TASK_PREDECESSOR_LEAVING
66 * Data attached with the tasks sent and received
68 typedef struct task_data {
69 e_task_type_t type; // type of task
70 int request_id; // id paramater (used by some types of tasks)
71 int request_finger; // finger parameter (used by some types of tasks)
72 int answer_id; // answer (used by some types of tasks)
73 char answer_to[MAILBOX_NAME_SIZE]; // mailbox to send an answer to (if any)
74 const char* issuer_host_name; // used for logging
75 } s_task_data_t, *task_data_t;
80 static void chord_initialize(void);
81 static int normalize(int id);
82 static int is_in_interval(int id, int start, int end);
83 static void get_mailbox(int host_id, char* mailbox);
84 static void task_data_destroy(task_data_t task_data);
85 static void print_finger_table(node_t node);
86 static void set_finger(node_t node, int finger_index, int id);
87 static void set_predecessor(node_t node, int predecessor_id);
90 static int node(int argc, char *argv[]);
91 static void handle_task(node_t node, m_task_t task);
94 static void create(node_t node);
95 static int join(node_t node, int known_id);
96 static void leave(node_t node);
97 static int find_successor(node_t node, int id);
98 static int remote_find_successor(node_t node, int ask_to_id, int id);
99 static int remote_get_predecessor(node_t node, int ask_to_id);
100 static int closest_preceding_node(node_t node, int id);
101 static void stabilize(node_t node);
102 static void notify(node_t node, int predecessor_candidate_id);
103 static void remote_notify(node_t node, int notify_to, int predecessor_candidate_id);
104 static void fix_fingers(node_t node);
105 static void check_predecessor(node_t node);
106 static void random_lookup(node_t);
107 static void quit_notify(node_t node, int to);
110 * \brief Global initialization of the Chord simulation.
112 static void chord_initialize(void)
114 // compute the powers of 2 once for all
115 powers2 = xbt_new(int, nb_bits);
118 for (i = 0; i < nb_bits; i++) {
123 DEBUG1("Sets nb_keys to %d", nb_keys);
127 * \brief Turns an id into an equivalent id in [0, nb_keys).
129 * \return the corresponding normalized id
131 static int normalize(int id)
137 // make sure id < nb_keys
144 * \brief Returns whether a id belongs to the interval [start, end].
146 * The parameters are noramlized to make sure they are between 0 and nb_keys - 1).
147 * 1 belongs to [62, 3]
148 * 1 does not belong to [3, 62]
149 * 63 belongs to [62, 3]
150 * 63 does not belong to [3, 62]
151 * 24 belongs to [21, 29]
152 * 24 does not belong to [29, 21]
154 * \param id id to check
155 * \param start lower bound
156 * \param end upper bound
157 * \return a non-zero value if id in in [start, end]
159 static int is_in_interval(int id, int start, int end)
162 start = normalize(start);
163 end = normalize(end);
165 // make sure end >= start and id >= start
178 * \brief Gets the mailbox name of a host given its chord id.
179 * \param node_id id of a node
180 * \param mailbox pointer to where the mailbox name should be written
181 * (there must be enough space)
183 static void get_mailbox(int node_id, char* mailbox)
185 snprintf(mailbox, MAILBOX_NAME_SIZE - 1, "%d", node_id);
189 * \brief Frees the memory used by some task data.
190 * \param task_data the task data to destroy
192 static void task_data_destroy(task_data_t task_data)
198 * \brief Displays the finger table of a node.
201 static void print_finger_table(node_t node)
203 if (XBT_LOG_ISENABLED(msg_chord, xbt_log_priority_verbose)) {
205 VERB0("My finger table:");
206 VERB0("Start | Succ ");
207 for (i = 0; i < nb_bits; i++) {
208 VERB2(" %3d | %3d ", (node->id + powers2[i]) % nb_keys, node->fingers[i].id);
210 VERB1("Predecessor: %d", node->pred_id);
215 * \brief Sets a finger of the current node.
216 * \param node the current node
217 * \param finger_index index of the finger to set (0 to nb_bits - 1)
218 * \param id the id to set for this finger
220 static void set_finger(node_t node, int finger_index, int id)
222 if (id != node->fingers[finger_index].id) {
223 node->fingers[finger_index].id = id;
224 get_mailbox(id, node->fingers[finger_index].mailbox);
225 node->last_change_date = MSG_get_clock();
226 DEBUG2("My new finger #%d is %d", finger_index, id);
231 * \brief Sets the predecessor of the current node.
232 * \param node the current node
233 * \param id the id to predecessor, or -1 to unset the predecessor
235 static void set_predecessor(node_t node, int predecessor_id)
237 if (predecessor_id != node->pred_id) {
238 node->pred_id = predecessor_id;
240 if (predecessor_id != -1) {
241 get_mailbox(predecessor_id, node->pred_mailbox);
243 node->last_change_date = MSG_get_clock();
245 DEBUG1("My new predecessor is %d", predecessor_id);
250 * \brief Node Function
253 * - the id of a guy I know in the system (except for the first node)
254 * - the time to sleep before I join (except for the first node)
256 int node(int argc, char *argv[])
258 double init_time = MSG_get_clock();
259 /*m_task_t task = NULL;*/
260 m_task_t task_received = NULL;
261 msg_comm_t comm_send = NULL;
264 int join_success = 0;
266 double next_stabilize_date = init_time + periodic_stabilize_delay;
267 double next_fix_fingers_date = init_time + periodic_fix_fingers_delay;
268 double next_check_predecessor_date = init_time + periodic_check_predecessor_delay;
269 double next_lookup_date = init_time + periodic_lookup_delay;
271 xbt_assert0(argc == 3 || argc == 5, "Wrong number of arguments for this node");
273 // initialize my node
275 node.id = atoi(argv[1]);
276 get_mailbox(node.id, node.mailbox);
277 node.next_finger_to_fix = 0;
278 node.comms = xbt_dynar_new(sizeof(msg_comm_t), NULL);
279 node.fingers = xbt_new0(s_finger_t, nb_bits);
280 node.last_change_date = init_time;
282 for (i = 0; i < nb_bits; i++) {
283 node.fingers[i].id = -1;
284 set_finger(&node, i, node.id);
287 if (argc == 3) { // first ring
288 deadline = atof(argv[2]);
293 int known_id = atoi(argv[2]);
294 //double sleep_time = atof(argv[3]);
295 deadline = atof(argv[4]);
298 // sleep before starting
299 DEBUG1("Let's sleep during %f", sleep_time);
300 MSG_process_sleep(sleep_time);
302 DEBUG0("Hey! Let's join the system.");
304 join_success = join(&node, known_id);
308 while (MSG_get_clock() < init_time + deadline
309 // && MSG_get_clock() < node.last_change_date + 1000
310 && MSG_get_clock() < max_simulation_time) {
312 if (node.comm_receive == NULL) {
313 task_received = NULL;
314 node.comm_receive = MSG_task_irecv(&task_received, node.mailbox);
315 // FIXME: do not make MSG_task_irecv() calls from several functions
318 if (!MSG_comm_test(node.comm_receive)) {
320 // no task was received: make some periodic calls
321 if (MSG_get_clock() >= next_stabilize_date) {
323 next_stabilize_date = MSG_get_clock() + periodic_stabilize_delay;
325 else if (MSG_get_clock() >= next_fix_fingers_date) {
327 next_fix_fingers_date = MSG_get_clock() + periodic_fix_fingers_delay;
329 else if (MSG_get_clock() >= next_check_predecessor_date) {
330 check_predecessor(&node);
331 next_check_predecessor_date = MSG_get_clock() + periodic_check_predecessor_delay;
333 else if (MSG_get_clock() >= next_lookup_date) {
334 random_lookup(&node);
335 next_lookup_date = MSG_get_clock() + periodic_lookup_delay;
338 // nothing to do: sleep for a while
339 MSG_process_sleep(5);
343 // a transfer has occured
345 MSG_error_t status = MSG_comm_get_status(node.comm_receive);
347 if (status != MSG_OK) {
348 DEBUG0("Failed to receive a task. Nevermind.");
349 node.comm_receive = NULL;
352 // the task was successfully received
353 MSG_comm_destroy(node.comm_receive);
354 node.comm_receive = NULL;
355 handle_task(&node, task_received);
359 // see if some communications are finished
360 while ((index = MSG_comm_testany(node.comms)) != -1) {
361 comm_send = xbt_dynar_get_as(node.comms, index, msg_comm_t);
362 MSG_error_t status = MSG_comm_get_status(comm_send);
363 xbt_dynar_remove_at(node.comms, index, &comm_send);
364 DEBUG3("Communication %p is finished with status %d, dynar size is now %lu",
365 comm_send, status, xbt_dynar_length(node.comms));
366 MSG_comm_destroy(comm_send);
370 // clean unfinished comms sent
371 /* unsigned int cursor;
372 xbt_dynar_foreach(node.comms, cursor, comm_send) {
373 task = MSG_comm_get_task(comm_send);
374 MSG_task_cancel(task);
375 task_data_destroy(MSG_task_get_data(task));
376 MSG_task_destroy(task);
377 MSG_comm_destroy(comm_send);
378 // FIXME: the task is actually not destroyed because MSG thinks that the other side (whose process is dead) is still using it
385 // stop the simulation
386 xbt_dynar_free(&node.comms);
387 xbt_free(node.fingers);
392 * \brief This function is called when the current node receives a task.
393 * \param node the current node
394 * \param task the task to handle (don't touch it then:
395 * it will be destroyed, reused or forwarded)
397 static void handle_task(node_t node, m_task_t task) {
399 DEBUG1("Handling task %p", task);
400 msg_comm_t comm = NULL;
401 char* mailbox = NULL;
402 task_data_t task_data = (task_data_t) MSG_task_get_data(task);
403 e_task_type_t type = task_data->type;
407 case TASK_FIND_SUCCESSOR:
408 DEBUG2("Receiving a 'Find Successor' request from %s for id %d",
409 task_data->issuer_host_name, task_data->request_id);
410 // is my successor the successor?
411 if (is_in_interval(task_data->request_id, node->id + 1, node->fingers[0].id)) {
412 task_data->type = TASK_FIND_SUCCESSOR_ANSWER;
413 task_data->answer_id = node->fingers[0].id;
414 DEBUG3("Sending back a 'Find Successor Answer' to %s: the successor of %d is %d",
415 task_data->issuer_host_name,
416 task_data->request_id, task_data->answer_id);
417 comm = MSG_task_isend(task, task_data->answer_to);
418 xbt_dynar_push(node->comms, &comm);
421 // otherwise, forward the request to the closest preceding finger in my table
422 int closest = closest_preceding_node(node, task_data->request_id);
423 DEBUG2("Forwarding the 'Find Successor' request for id %d to my closest preceding finger %d",
424 task_data->request_id, closest);
425 get_mailbox(closest, mailbox);
426 comm = MSG_task_isend(task, mailbox);
427 xbt_dynar_push(node->comms, &comm);
432 case TASK_GET_PREDECESSOR:
433 DEBUG1("Receiving a 'Get Predecessor' request from %s", task_data->issuer_host_name);
434 task_data->type = TASK_GET_PREDECESSOR_ANSWER;
435 task_data->answer_id = node->pred_id;
436 DEBUG3("Sending back a 'Get Predecessor Answer' to %s via mailbox '%s': my predecessor is %d",
437 task_data->issuer_host_name,
438 task_data->answer_to, task_data->answer_id);
439 comm = MSG_task_isend(task, task_data->answer_to);
440 xbt_dynar_push(node->comms, &comm);
444 // someone is telling me that he may be my new predecessor
445 DEBUG1("Receiving a 'Notify' request from %s", task_data->issuer_host_name);
446 notify(node, task_data->request_id);
447 task_data_destroy(task_data);
448 MSG_task_destroy(task);
451 case TASK_PREDECESSOR_LEAVING:
452 // my predecessor is about to quit
453 DEBUG1("Receiving a 'Predecessor Leaving' message from %s", task_data->issuer_host_name);
454 // modify my predecessor
455 set_predecessor(node, task_data->request_id);
456 task_data_destroy(task_data);
457 MSG_task_destroy(task);
459 >> notify my new predecessor
460 >> send a notify_predecessors !!
464 case TASK_SUCCESSOR_LEAVING:
465 // my successor is about to quit
466 DEBUG1("Receiving a 'Successor Leaving' message from %s", task_data->issuer_host_name);
467 // modify my successor FIXME : this should be implicit ?
468 set_finger(node, 0, task_data->request_id);
469 task_data_destroy(task_data);
470 MSG_task_destroy(task);
472 >> notify my new successor
473 >> update my table & predecessors table */
476 case TASK_FIND_SUCCESSOR_ANSWER:
477 case TASK_GET_PREDECESSOR_ANSWER:
478 DEBUG2("Ignoring unexpected task of type %d (%p)", type, task);
484 * \brief Initializes the current node as the first one of the system.
485 * \param node the current node
487 static void create(node_t node)
489 DEBUG0("Create a new Chord ring...");
490 set_predecessor(node, -1); // -1 means that I have no predecessor
491 print_finger_table(node);
495 * \brief Makes the current node join the ring, knowing the id of a node
496 * already in the ring
497 * \param node the current node
498 * \param known_id id of a node already in the ring
499 * \return 1 if the join operation succeeded, 0 otherwise
501 static int join(node_t node, int known_id)
503 INFO2("Joining the ring with id %d, knowing node %d", node->id, known_id);
504 set_predecessor(node, -1); // no predecessor (yet)
506 int successor_id = remote_find_successor(node, known_id, node->id);
507 if (successor_id == -1) {
508 INFO0("Cannot join the ring.");
511 set_finger(node, 0, successor_id);
512 print_finger_table(node);
515 return successor_id != -1;
519 * \brief Makes the current node quit the system
520 * \param node the current node
522 static void leave(node_t node)
524 DEBUG0("Well Guys! I Think it's time for me to quit ;)");
525 quit_notify(node, 1); // notify to my successor ( >>> 1 );
526 quit_notify(node, -1); // notify my predecessor ( >>> -1);
531 * \brief Notifies the successor or the predecessor of the current node
533 * \param node the current node
534 * \param to 1 to notify the successor, -1 to notify the predecessor
535 * FIXME: notify both nodes with only one call
537 static void quit_notify(node_t node, int to)
540 task_data_t req_data = xbt_new0(s_task_data_t, 1);
541 req_data->request_id = node->id;
542 req_data->successor_id = node->fingers[0].id;
543 req_data->pred_id = node->pred_id;
544 req_data->issuer_host_name = MSG_host_get_name(MSG_host_self());
545 req_data->answer_to = NULL;
546 const char* task_name = NULL;
547 const char* to_mailbox = NULL;
548 if (to == 1) { // notify my successor
549 to_mailbox = node->fingers[0].mailbox;
550 INFO2("Telling my Successor %d about my departure via mailbox %s",
551 node->fingers[0].id, to_mailbox);
552 req_data->type = TASK_PREDECESSOR_LEAVING;
554 else if (to == -1) { // notify my predecessor
556 if (node->pred_id == -1) {
560 to_mailbox = node->pred_mailbox;
561 INFO2("Telling my Predecessor %d about my departure via mailbox %s",
562 node->pred_id, to_mailbox);
563 req_data->type = TASK_SUCCESSOR_LEAVING;
565 m_task_t task = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data);
566 //char* mailbox = get_mailbox(to_mailbox);
567 msg_comm_t comm = MSG_task_isend(task, to_mailbox);
568 xbt_dynar_push(node->comms, &comm);
573 * \brief Makes the current node find the successor node of an id.
574 * \param node the current node
575 * \param id the id to find
576 * \return the id of the successor node, or -1 if the request failed
578 static int find_successor(node_t node, int id)
580 // is my successor the successor?
581 if (is_in_interval(id, node->id + 1, node->fingers[0].id)) {
582 return node->fingers[0].id;
585 // otherwise, ask the closest preceding finger in my table
586 int closest = closest_preceding_node(node, id);
587 return remote_find_successor(node, closest, id);
591 * \brief Asks another node the successor node of an id.
592 * \param node the current node
593 * \param ask_to the node to ask to
594 * \param id the id to find
595 * \return the id of the successor node, or -1 if the request failed
597 static int remote_find_successor(node_t node, int ask_to, int id)
601 char mailbox[MAILBOX_NAME_SIZE];
602 get_mailbox(ask_to, mailbox);
603 task_data_t req_data = xbt_new0(s_task_data_t, 1);
604 req_data->type = TASK_FIND_SUCCESSOR;
605 req_data->request_id = id;
606 get_mailbox(node->id, req_data->answer_to);
607 req_data->issuer_host_name = MSG_host_get_name(MSG_host_self());
609 // send a "Find Successor" request to ask_to_id
610 m_task_t task_sent = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data);
611 DEBUG3("Sending a 'Find Successor' request (task %p) to %d for id %d", task_sent, ask_to, id);
612 MSG_error_t res = MSG_task_send_with_timeout(task_sent, mailbox, timeout);
615 DEBUG3("Failed to send the 'Find Successor' request (task %p) to %d for id %d",
616 task_sent, ask_to, id);
617 MSG_task_destroy(task_sent);
618 task_data_destroy(req_data);
622 // receive the answer
623 DEBUG3("Sent a 'Find Successor' request (task %p) to %d for key %d, waiting for the answer",
624 task_sent, ask_to, id);
627 if (node->comm_receive == NULL) {
628 m_task_t task_received = NULL;
629 node->comm_receive = MSG_task_irecv(&task_received, node->mailbox);
632 res = MSG_comm_wait(node->comm_receive, timeout);
635 DEBUG2("Failed to receive the answer to my 'Find Successor' request (task %p): %d",
638 //MSG_comm_destroy(node->comm_receive);
641 m_task_t task_received = MSG_comm_get_task(node->comm_receive);
642 DEBUG1("Received a task (%p)", task_received);
643 task_data_t ans_data = MSG_task_get_data(task_received);
645 MC_assert(task_received == task_sent);
647 if (task_received != task_sent) {
648 // this is not the expected answer
649 handle_task(node, task_received);
652 // this is our answer
653 DEBUG4("Received the answer to my 'Find Successor' request for id %d (task %p): the successor of key %d is %d",
654 ans_data->request_id, task_received, id, ans_data->answer_id);
655 successor = ans_data->answer_id;
657 MSG_task_destroy(task_received);
658 task_data_destroy(req_data);
661 MSG_comm_destroy(node->comm_receive);
662 node->comm_receive = NULL;
670 * \brief Asks another node its predecessor.
671 * \param node the current node
672 * \param ask_to the node to ask to
673 * \return the id of its predecessor node, or -1 if the request failed
674 * (or if the node does not know its predecessor)
676 static int remote_get_predecessor(node_t node, int ask_to)
678 int predecessor_id = -1;
680 char mailbox[MAILBOX_NAME_SIZE];
681 get_mailbox(ask_to, mailbox);
682 task_data_t req_data = xbt_new0(s_task_data_t, 1);
683 req_data->type = TASK_GET_PREDECESSOR;
684 get_mailbox(node->id, req_data->answer_to);
685 req_data->issuer_host_name = MSG_host_get_name(MSG_host_self());
687 // send a "Get Predecessor" request to ask_to_id
688 DEBUG1("Sending a 'Get Predecessor' request to %d", ask_to);
689 m_task_t task_sent = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data);
690 MSG_error_t res = MSG_task_send_with_timeout(task_sent, mailbox, timeout);
693 DEBUG2("Failed to send the 'Get Predecessor' request (task %p) to %d",
695 MSG_task_destroy(task_sent);
696 task_data_destroy(req_data);
700 // receive the answer
701 DEBUG3("Sent 'Get Predecessor' request (task %p) to %d, waiting for the answer on my mailbox '%s'",
702 task_sent, ask_to, req_data->answer_to);
705 if (node->comm_receive == NULL) { // FIXME simplify this
706 m_task_t task_received = NULL;
707 node->comm_receive = MSG_task_irecv(&task_received, node->mailbox);
710 res = MSG_comm_wait(node->comm_receive, timeout);
713 DEBUG2("Failed to receive the answer to my 'Get Predecessor' request (task %p): %d",
716 //MSG_comm_destroy(node->comm_receive);
719 m_task_t task_received = MSG_comm_get_task(node->comm_receive);
720 task_data_t ans_data = MSG_task_get_data(task_received);
722 MC_assert(task_received == task_sent);
724 if (task_received != task_sent) {
725 handle_task(node, task_received);
728 DEBUG3("Received the answer to my 'Get Predecessor' request (task %p): the predecessor of node %d is %d",
729 task_received, ask_to, ans_data->answer_id);
730 predecessor_id = ans_data->answer_id;
732 MSG_task_destroy(task_received);
733 task_data_destroy(req_data);
736 MSG_comm_destroy(node->comm_receive);
737 node->comm_receive = NULL;
741 return predecessor_id;
745 * \brief Returns the closest preceding finger of an id
746 * with respect to the finger table of the current node.
747 * \param node the current node
748 * \param id the id to find
749 * \return the closest preceding finger of that id
751 int closest_preceding_node(node_t node, int id)
754 for (i = nb_bits - 1; i >= 0; i--) {
755 if (is_in_interval(node->fingers[i].id, node->id + 1, id - 1)) {
756 return node->fingers[i].id;
763 * \brief This function is called periodically. It checks the immediate
764 * successor of the current node.
765 * \param node the current node
767 static void stabilize(node_t node)
769 DEBUG0("Stabilizing node");
771 // get the predecessor of my immediate successor
773 int successor_id = node->fingers[0].id;
774 if (successor_id != node->id) {
775 candidate_id = remote_get_predecessor(node, successor_id);
778 candidate_id = node->pred_id;
781 // this node is a candidate to become my new successor
782 if (candidate_id != -1
783 && is_in_interval(candidate_id, node->id + 1, successor_id - 1)) {
784 set_finger(node, 0, candidate_id);
786 if (successor_id != node->id) {
787 remote_notify(node, successor_id, node->id);
792 * \brief Notifies the current node that its predecessor may have changed.
793 * \param node the current node
794 * \param candidate_id the possible new predecessor
796 static void notify(node_t node, int predecessor_candidate_id) {
798 if (node->pred_id == -1
799 || is_in_interval(predecessor_candidate_id, node->pred_id + 1, node->id - 1)) {
801 set_predecessor(node, predecessor_candidate_id);
802 print_finger_table(node);
805 DEBUG1("I don't have to change my predecessor to %d", predecessor_candidate_id);
810 * \brief Notifies a remote node that its predecessor may have changed.
811 * \param node the current node
812 * \param notify_id id of the node to notify
813 * \param candidate_id the possible new predecessor
815 static void remote_notify(node_t node, int notify_id, int predecessor_candidate_id) {
817 task_data_t req_data = xbt_new0(s_task_data_t, 1);
818 req_data->type = TASK_NOTIFY;
819 req_data->request_id = predecessor_candidate_id;
820 req_data->issuer_host_name = MSG_host_get_name(MSG_host_self());
822 // send a "Notify" request to notify_id
823 m_task_t task = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data);
824 DEBUG2("Sending a 'Notify' request (task %p) to %d", task, notify_id);
825 char mailbox[MAILBOX_NAME_SIZE];
826 get_mailbox(notify_id, mailbox);
827 msg_comm_t comm = MSG_task_isend(task, mailbox);
828 xbt_dynar_push(node->comms, &comm);
832 * \brief This function is called periodically.
833 * It refreshes the finger table of the current node.
834 * \param node the current node
836 static void fix_fingers(node_t node) {
838 DEBUG0("Fixing fingers");
839 int i = node->next_finger_to_fix;
840 int id = find_successor(node, node->id + powers2[i]);
843 if (id != node->fingers[i].id) {
844 set_finger(node, i, id);
845 print_finger_table(node);
847 node->next_finger_to_fix = (i + 1) % nb_bits;
852 * \brief This function is called periodically.
853 * It checks whether the predecessor has failed
854 * \param node the current node
856 static void check_predecessor(node_t node)
858 DEBUG0("Checking whether my predecessor is alive");
863 * \brief Performs a find successor request to a random id.
864 * \param node the current node
866 static void random_lookup(node_t node)
868 int id = 1337; // TODO pick a pseudorandom id
869 DEBUG1("Making a lookup request for id %d", id);
870 find_successor(node, id);
874 * \brief Main function.
876 int main(int argc, char *argv[])
879 printf("Usage: %s [-nb_bits=n] [-timeout=t] platform_file deployment_file\n", argv[0]);
880 printf("example: %s ../msg_platform.xml chord.xml\n", argv[0]);
884 MSG_global_init(&argc, argv);
886 char **options = &argv[1];
887 while (!strncmp(options[0], "-", 1)) {
889 int length = strlen("-nb_bits=");
890 if (!strncmp(options[0], "-nb_bits=", length) && strlen(options[0]) > length) {
891 nb_bits = atoi(options[0] + length);
892 DEBUG1("Set nb_bits to %d", nb_bits);
896 length = strlen("-timeout=");
897 if (!strncmp(options[0], "-timeout=", length) && strlen(options[0]) > length) {
898 timeout = atoi(options[0] + length);
899 DEBUG1("Set timeout to %d", timeout);
902 xbt_assert1(0, "Invalid chord option '%s'", options[0]);
908 const char* platform_file = options[0];
909 const char* application_file = options[1];
913 MSG_set_channel_number(0);
914 MSG_create_environment(platform_file);
916 MSG_function_register("node", node);
917 MSG_launch_application(application_file);
919 MSG_error_t res = MSG_main();
920 INFO1("Simulation time: %g", MSG_get_clock());