X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/f27a63f2703cba8d48efc7e175102ca30e3748ab..c2f8851217b62c872f98ef5233d6c53318844e31:/examples/msg/chord/chord.c diff --git a/examples/msg/chord/chord.c b/examples/msg/chord/chord.c index 38728bdb13..88987d7aa7 100644 --- a/examples/msg/chord/chord.c +++ b/examples/msg/chord/chord.c @@ -1,3 +1,4 @@ + /* Copyright (c) 2010. The SimGrid Team. * All rights reserved. */ @@ -5,363 +6,861 @@ * under the terms of the license (GNU LGPL) which comes with this package. */ #include -#include #include "msg/msg.h" -#include "xbt/sysdep.h" /* calloc, printf */ - -/* Create a log channel to have nice outputs. */ #include "xbt/log.h" #include "xbt/asserts.h" -XBT_LOG_NEW_DEFAULT_CATEGORY(msg_test, +XBT_LOG_NEW_DEFAULT_CATEGORY(msg_chord, "Messages specific for this msg example"); -#define KEY_BITS 6 -#define CHORD_NB_KEYS 64 -/* -* Finger Element -*/ -typedef struct{ - int id; - const char *host_name; - const char *mailbox; -} finger_elem; +#define NB_BITS 16 +#define NB_KEYS 65536 +#define COMM_SIZE 10 +#define COMP_SIZE 0 +#define TIMEOUT 50 -/* - * Node Data +/** + * Finger element. */ -typedef struct{ - int id; // my id - const char *host_name; //my host name - const char* mailbox; //my mailbox - int fingers_nb; // size of finger list - finger_elem* fingers; // finger list [ fingers[0] >> Successor - int next; //next finger to fix - int pred_id; // predecessor id - const char* pred_host_name; // predecessor host name - const char* pred_mailbox; // predecessor mailbox -}data_node; - -//global; +typedef struct finger { + int id; + char* mailbox; +} s_finger_t, *finger_t; +/** + * Node data. + */ +typedef struct node { + int id; // my id + char* mailbox; // my usual mailbox name + s_finger_t fingers[NB_BITS]; // finger table (fingers[0] is my successor) + int pred_id; // predecessor id + char* pred_mailbox; // predecessor's mailbox name + int next_finger_to_fix; // index of the next finger to fix in fix_fingers() + msg_comm_t comm_receive; // current communication to receive + xbt_dynar_t comms; // current communications being sent +} s_node_t, *node_t; + +/** + * Types of tasks exchanged between nodes. + */ +typedef enum { + TASK_FIND_SUCCESSOR, + TASK_FIND_SUCCESSOR_ANSWER, + TASK_GET_PREDECESSOR, + TASK_GET_PREDECESSOR_ANSWER, + TASK_NOTIFY, + TASK_SUCCESSOR_LEAVING, + TASK_PREDECESSOR_LEAVING +} e_task_type_t; + +/** + * Data attached with the tasks sent and received + */ +typedef struct task_data { + e_task_type_t type; // type of task + int request_id; // id paramater (used by some types of tasks) + int request_finger; // finger parameter (used by some types of tasks) + int answer_id; // answer (used by some types of tasks) + char* answer_to; // mailbox to send an answer to (or NULL) + const char* issuer_host_name; // used for logging +} s_task_data_t, *task_data_t; + +static int powers2[NB_BITS]; + +// utility functions +static void chord_initialize(void); +static int normalize(int id); +static int is_in_interval(int id, int start, int end); +static char* get_mailbox(int host_id); +static void task_data_destroy(task_data_t task_data); +static void print_finger_table(node_t node); +static void set_finger(node_t node, int finger_index, int id); +static void set_predecessor(node_t node, int predecessor_id); + +// process functions static int node(int argc, char *argv[]); -static int sender(int argc,char *argv[]); -static void find_successor_node(data_node *my_data, m_task_t join_task); -static int find_successor(data_node* my_data, int id); -static const char* find_closest_preceding(data_node* n_node, int id); //return a mailbox -static int get_successor_id(m_host_t); +static void handle_task(node_t node, m_task_t task); + +// Chord core +static void create(node_t node); +static int join(node_t node, int known_id); +static void leave(node_t node); +static int find_successor(node_t node, int id); +static int remote_find_successor(node_t node, int ask_to_id, int id); +static int remote_get_predecessor(node_t node, int ask_to_id); +static int closest_preceding_node(node_t node, int id); +static void stabilize(node_t node); +static void notify(node_t node, int predecessor_candidate_id); +static void remote_notify(node_t node, int notify_to, int predecessor_candidate_id); +static void fix_fingers(node_t node); +static void check_predecessor(node_t node); +static void quit_notify(node_t node, int to); + +/** + * \brief Global initialization of the Chord simulation. + */ +static void chord_initialize(void) +{ + // compute the powers of 2 once for all + int pow = 1; + int i; + for (i = 0; i < NB_BITS; i++) { + powers2[i] = pow; + pow = pow << 1; + } +} -static MSG_error_t test_all(const char *platform_file, - const char *application_file); -static void init_finger_table(data_node *data, int known_id); +/** + * \brief Turns an id into an equivalent id in [0, NB_KEYS). + * \param id an id + * \return the corresponding normalized id + */ +static int normalize(int id) +{ + // make sure id >= 0 + while (id < 0) { + id += NB_KEYS; + } + // make sure id < NB_KEYS + id = id % NB_KEYS; -static int is_in_interval(unsigned int id, unsigned int start, unsigned int end) { + return id; +} - id = id % CHORD_NB_KEYS; - start = start % CHORD_NB_KEYS; - end = end % CHORD_NB_KEYS; +/** + * \brief Returns whether a id belongs to the interval [start, end]. + * + * The parameters are noramlized to make sure they are between 0 and CHORD_NB_KEYS - 1). + * 1 belongs to [62, 3] + * 1 does not belong to [3, 62] + * 63 belongs to [62, 3] + * 63 does not belong to [3, 62] + * 24 belongs to [21, 29] + * 24 does not belong to [29, 21] + * + * \param id id to check + * \param start lower bound + * \param end upper bound + * \return a non-zero value if id in in [start, end] + */ +static int is_in_interval(int id, int start, int end) +{ + id = normalize(id); + start = normalize(start); + end = normalize(end); - /* make sure end >= start and id >= start */ + // make sure end >= start and id >= start if (end < start) { - end += CHORD_NB_KEYS; + end += NB_KEYS; } if (id < start) { - id += CHORD_NB_KEYS; + id += NB_KEYS; } - return id < end; + return id <= end; } -/* - * Node Function +/** + * \brief Gets the mailbox name of a host given its chord id. + * \param node_id id of a node + * \return the name of its mailbox + */ +static char* get_mailbox(int node_id) +{ + return bprintf("mailbox%d", node_id); +} + +/** + * \brief Frees the memory used by some task data. + * \param task_data the task data to destroy + */ +static void task_data_destroy(task_data_t task_data) +{ + xbt_free(task_data->answer_to); + xbt_free(task_data); +} + +/** + * \brief Displays the finger table of a node. + * \param node a node + */ +static void print_finger_table(node_t node) +{ + if (XBT_LOG_ISENABLED(msg_chord, xbt_log_priority_verbose)) { + int i; + int pow = 1; + VERB0("My finger table:"); + VERB0("Start | Succ "); + for (i = 0; i < NB_BITS; i++) { + VERB2(" %3d | %3d ", (node->id + pow) % NB_KEYS, node->fingers[i].id); + pow = pow << 1; + } + VERB1("Predecessor: %d", node->pred_id); + } +} + +/** + * \brief Sets a finger of the current node. + * \param node the current node + * \param finger_index index of the finger to set (0 to NB_BITS - 1) + * \param id the id to set for this finger + */ +static void set_finger(node_t node, int finger_index, int id) +{ + node->fingers[finger_index].id = id; + xbt_free(node->fingers[finger_index].mailbox); + node->fingers[finger_index].mailbox = get_mailbox(id); + DEBUG2("My new finger #%d is %d", finger_index, id); +} + +/** + * \brief Sets the predecessor of the current node. + * \param node the current node + * \param id the id to predecessor, or -1 to unset the predecessor */ +static void set_predecessor(node_t node, int predecessor_id) +{ + node->pred_id = predecessor_id; + xbt_free(node->pred_mailbox); + + if (predecessor_id != -1) { + node->pred_mailbox = get_mailbox(predecessor_id); + } + + DEBUG1("My new predecessor is %d", predecessor_id); +} -/* - - - - - - >argument value="time_to_sleep"/> - -*/ -static int cpt = 0; +/** + * \brief Node Function + * Arguments: + * - my id + * - the id of a guy I know in the system (except for the first node) + * - the time to sleep before I join (except for the first node) + */ int node(int argc, char *argv[]) { - m_task_t recv_request = NULL; - int first = 1; - int joined = 0; - int res,create = 0; - if ( argc == 3) // if no known host are declared >>> first node >>> create chord ring - { - create = 1; - } - - //int id = atoi(argv[1]); - //int mailbox = atoi(argv[2]); - // init data node - data_node *data = xbt_new(data_node,1); - data->host_name = MSG_host_get_name(MSG_host_self()); - data->id = atoi(argv[1]); - data->mailbox = argv[2]; - data->fingers_nb = 1; - data->fingers = xbt_new(finger_elem,KEY_BITS); - data->fingers[0].host_name = data->host_name; - data->fingers[0].id = data->id; - data->fingers[0].mailbox = data->mailbox; - data->next = 0; - data->pred_host_name = NULL; - data->pred_id = -1; - data->pred_mailbox = NULL; + double init_time = MSG_get_clock(); + m_task_t task = NULL; + m_task_t task_received = NULL; + msg_comm_t comm_send = NULL; + int i; + int index; + int join_success = 0; + double deadline; + double next_stabilize_date = init_time + 10; + double next_fix_fingers_date = init_time + 10; + double next_check_predecessor_date = init_time + 10; + + xbt_assert0(argc == 3 || argc == 5, "Wrong number of arguments for this node"); + + // initialize my node + s_node_t node = {0}; + node.id = atoi(argv[1]); + node.mailbox = get_mailbox(node.id); + node.next_finger_to_fix = 0; + node.comms = xbt_dynar_new(sizeof(msg_comm_t), NULL); + + for (i = 0; i < NB_BITS; i++) { + set_finger(&node, i, node.id); + } -/* - * Ring Point Entry Node + if (argc == 3) { // first ring + deadline = atof(argv[2]); + create(&node); + join_success = 1; + } + else { + int known_id = atoi(argv[2]); + double sleep_time = atof(argv[3]); + deadline = atof(argv[4]); + + // sleep before starting + DEBUG1("Let's sleep during %f", sleep_time); + MSG_process_sleep(sleep_time); + DEBUG0("Hey! Let's join the system."); + + join_success = join(&node, known_id); + } + + if (join_success) { + while (MSG_get_clock() < init_time + deadline) { + + if (node.comm_receive == NULL) { + task_received = NULL; + node.comm_receive = MSG_task_irecv(&task_received, node.mailbox); + // FIXME: do not make MSG_task_irecv() calls from several functions + } + + if (!MSG_comm_test(node.comm_receive)) { + + // no task was received: make some periodic calls + if (MSG_get_clock() >= next_stabilize_date) { + stabilize(&node); + next_stabilize_date = MSG_get_clock() + 10; + } + else if (MSG_get_clock() >= next_fix_fingers_date) { + fix_fingers(&node); + next_fix_fingers_date = MSG_get_clock() + 10; + } + else if (MSG_get_clock() >= next_check_predecessor_date) { + check_predecessor(&node); + next_check_predecessor_date = MSG_get_clock() + 10; + } + else { + // nothing to do: sleep for a while + MSG_process_sleep(5); + } + } + else { + // a transfer has occured + + MSG_error_t status = MSG_comm_get_status(node.comm_receive); + + if (status != MSG_OK) { + DEBUG0("Failed to receive a task. Nevermind."); + node.comm_receive = NULL; + } + else { + // the task was successfully received + MSG_comm_destroy(node.comm_receive); + node.comm_receive = NULL; + handle_task(&node, task_received); + } + } + + // see if some communications are finished + while ((index = MSG_comm_testany(node.comms)) != -1) { + comm_send = xbt_dynar_get_as(node.comms, index, msg_comm_t); + MSG_error_t status = MSG_comm_get_status(comm_send); + xbt_dynar_remove_at(node.comms, index, &comm_send); + DEBUG3("Communication %p is finished with status %d, dynar size is now %lu", + comm_send, status, xbt_dynar_length(node.comms)); + MSG_comm_destroy(comm_send); + } + } + + // clean unfinished comms sent + unsigned int cursor; + xbt_dynar_foreach(node.comms, cursor, comm_send) { + task = MSG_comm_get_task(comm_send); + MSG_task_cancel(task); + task_data_destroy(MSG_task_get_data(task)); + MSG_task_destroy(task); + MSG_comm_destroy(comm_send); + // FIXME: the task is actually not destroyed because MSG thinks that the other side (whose process is dead) is still using it + } + + // leave the ring + leave(&node); + } + + // stop the simulation + xbt_dynar_free(&node.comms); + xbt_free(node.mailbox); + xbt_free(node.pred_mailbox); + for (i = 0; i < NB_BITS - 1; i++) { + xbt_free(node.fingers[i].mailbox); + } + return 0; +} + +/** + * \brief This function is called when the current node receives a task. + * \param node the current node + * \param task the task to handle (don't touch it then: + * it will be destroyed, reused or forwarded) */ - if (create) // first ring - { - INFO0("Create new Chord Ring..."); - joined = 1; - cpt++; - //sucessor = n - data->fingers[0].host_name = data->host_name; - data->fingers[0].id = data->id; - data->fingers[0].mailbox = data->mailbox; - while(cpt < MSG_get_host_number()-1) //make condition!!! - { - recv_request = NULL; - res = MSG_task_receive(&(recv_request),data->mailbox); - xbt_assert0(res == MSG_OK, "MSG_receiev failed"); - if (!strcmp(MSG_task_get_name(recv_request), "Join Call")) - { - if(MSG_task_get_data(recv_request)==NULL) - { - WARN0("Receiving an Empty Data"); - } - data_node *recv_data = (data_node*)MSG_task_get_data(recv_request); - INFO1("Receiving a Join Call from %s",recv_data->host_name); - if (first) - { - // predecessor(recv_data) >>>> data - recv_data->pred_host_name = data->host_name; - recv_data->pred_id = data->id; - recv_data->pred_mailbox = data->mailbox; - data->fingers_nb = 1; - // successor(recv_data) >>> data - recv_data->fingers[0].id = data->id; - recv_data->fingers[0].host_name = data->host_name; - recv_data->fingers[0].mailbox = data->mailbox; - //successor(data) >>>> recv_data - data->fingers[data->fingers_nb - 1].host_name = recv_data->host_name; - data->fingers[data->fingers_nb - 1].id = recv_data->id; - data->fingers[data->fingers_nb - 1].mailbox = recv_data->mailbox; - INFO1("Sending back a Join Request to %s",recv_data->host_name); - MSG_task_set_name(recv_request,"Join Response"); - MSG_task_send(recv_request,recv_data->mailbox); - first = 0; - } - else{ - find_successor_node(data,recv_request); - } - - } - } - } -/* - * Joining Node +static void handle_task(node_t node, m_task_t task) { + + DEBUG1("Handling task %p", task); + msg_comm_t comm = NULL; + char* mailbox = NULL; + task_data_t task_data = (task_data_t) MSG_task_get_data(task); + e_task_type_t type = task_data->type; + + switch (type) { + + case TASK_FIND_SUCCESSOR: + DEBUG2("Receiving a 'Find Successor' request from %s for id %d", + task_data->issuer_host_name, task_data->request_id); + // is my successor the successor? + if (is_in_interval(task_data->request_id, node->id + 1, node->fingers[0].id)) { + task_data->type = TASK_FIND_SUCCESSOR_ANSWER; + task_data->answer_id = node->fingers[0].id; + DEBUG3("Sending back a 'Find Successor Answer' to %s: the successor of %d is %d", + task_data->issuer_host_name, + task_data->request_id, task_data->answer_id); + comm = MSG_task_isend(task, task_data->answer_to); + xbt_dynar_push(node->comms, &comm); + } + else { + // otherwise, forward the request to the closest preceding finger in my table + int closest = closest_preceding_node(node, task_data->request_id); + DEBUG2("Forwarding the 'Find Successor' request for id %d to my closest preceding finger %d", + task_data->request_id, closest); + mailbox = get_mailbox(closest); + comm = MSG_task_isend(task, mailbox); + xbt_dynar_push(node->comms, &comm); + xbt_free(mailbox); + } + break; + + case TASK_GET_PREDECESSOR: + DEBUG1("Receiving a 'Get Predecessor' request from %s", task_data->issuer_host_name); + task_data->type = TASK_GET_PREDECESSOR_ANSWER; + task_data->answer_id = node->pred_id; + DEBUG3("Sending back a 'Get Predecessor Answer' to %s via mailbox '%s': my predecessor is %d", + task_data->issuer_host_name, + task_data->answer_to, task_data->answer_id); + comm = MSG_task_isend(task, task_data->answer_to); + xbt_dynar_push(node->comms, &comm); + break; + + case TASK_NOTIFY: + // someone is telling me that he may be my new predecessor + DEBUG1("Receiving a 'Notify' request from %s", task_data->issuer_host_name); + notify(node, task_data->request_id); + task_data_destroy(task_data); + MSG_task_destroy(task); + break; + + case TASK_PREDECESSOR_LEAVING: + // my predecessor is about to quit + DEBUG1("Receiving a 'Predecessor Leaving' message from %s", task_data->issuer_host_name); + // modify my predecessor + set_predecessor(node, task_data->request_id); + task_data_destroy(task_data); + MSG_task_destroy(task); + /*TODO : + >> notify my new predecessor + >> send a notify_predecessors !! + */ + break; + + case TASK_SUCCESSOR_LEAVING: + // my successor is about to quit + DEBUG1("Receiving a 'Successor Leaving' message from %s", task_data->issuer_host_name); + // modify my successor FIXME : this should be implicit ? + set_finger(node, 0, task_data->request_id); + task_data_destroy(task_data); + MSG_task_destroy(task); + /* TODO + >> notify my new successor + >> update my table & predecessors table */ + break; + + case TASK_FIND_SUCCESSOR_ANSWER: + case TASK_GET_PREDECESSOR_ANSWER: + DEBUG2("Ignoring unexpected task of type %d (%p)", type, task); + break; + } +} + +/** + * \brief Initializes the current node as the first one of the system. + * \param node the current node */ - else if(!create) - { - //Sleep Before Starting - INFO1("Let's Sleep >>%i",atoi(argv[6])); - MSG_process_sleep(atoi(argv[5])); - INFO0("Hey! Let's Send a Join Request"); - //send a join task to the known host via its(known host) mailbox - const char* known_host_name = argv[3]; - const char* known_mailbox = argv[4]; - int known_id = atoi(argv[5]); - m_task_t join_request = MSG_task_create("Join Call",10000,2000,data); // define comp size and comm size (#define ...) - INFO2("Sending a join request to %s via mailbox %s",known_host_name,known_mailbox); - MSG_task_send(join_request,known_mailbox); - //wait for answer on my mailbox - while(cpt < MSG_get_host_number()-1) - { - recv_request = NULL; - int res = MSG_task_receive(&(recv_request),data->mailbox); - //check if it's the response for my request - xbt_assert0(res == MSG_OK, "MSG_receiev failed"); - // get data - data_node *recv_data = (data_node*)MSG_task_get_data(recv_request); - // Join Call Message - if(!strcmp(MSG_task_get_name(recv_request), "Join Call")) - { - - INFO1("Receiving Join Call From %s",recv_data->host_name); - if(!joined) - { - INFO1("Sorry %s... I'm not yet joined",recv_data->host_name); - //No Treatment - MSG_task_set_name(recv_request,"Join Failed"); - MSG_task_send(recv_request,recv_data->mailbox); - } - else - { - find_successor_node(data,recv_request); - } - - } - // Join Response - else if(!strcmp(MSG_task_get_name(recv_request), "Join Response")) - { - INFO0("Receiving Join Response!!!"); - INFO1("My successor is : %s",data->fingers[0].host_name); - INFO1("My Predecessor is : %s",data->pred_host_name); - cpt++; - joined = 1; - INFO1("My finger table size : %i",data->fingers_nb); - INFO0("***********************************************************************"); - - /* - MSG_task_set_name(recv_request,"Fix Fingers"); - - MSG_task_send(recv_request,data->pred_mailbox); - MSG_task_send(recv_request,data->fingers[0].mailbox); - */ - init_finger_table(data, known_id); - - //treatment - } - // Join Failure Message - else if(!strcmp(MSG_task_get_name(recv_request), "Join Failed")) - { - INFO0("My Join call has failed... let's Try Again"); - // send back - //MSG_task_send(join_request,known_mailbox); - // !!!!!!!!! YVes Jaques Always...???§§§§************************** - - } - else if(!strcmp(MSG_task_get_name(recv_request), "Fix Fingers")) - { - int i; - for(i = KEY_BITS -1 ; i>= 0;i--) - { - //data->fingers[i] = find_finger_elem(data,(data->id)+pow(2,i-1)); - } - } - } - } - return 0; +static void create(node_t node) +{ + DEBUG0("Create a new Chord ring..."); + set_predecessor(node, -1); // -1 means that I have no predecessor + print_finger_table(node); } -/* - * Initializes +/** + * \brief Makes the current node join the ring, knowing the id of a node + * already in the ring + * \param node the current node + * \param known_id id of a node already in the ring + * \return 1 if the join operation succeeded, 0 otherwise */ -void init_finger_table(data_node *node, int known_id) { +static int join(node_t node, int known_id) +{ + INFO2("Joining the ring with id %d, knowing node %d", node->id, known_id); + set_predecessor(node, -1); // no predecessor (yet) - // ask known_id who is my immediate successor -// data->fingers[0].id = remote_find_successor(known_id, data->id + 1); + int successor_id = remote_find_successor(node, known_id, node->id); + if (successor_id == -1) { + INFO0("Cannot join the ring."); + } + else { + set_finger(node, 0, successor_id); + print_finger_table(node); + } + + return successor_id != -1; +} + +/** + * \brief Makes the current node quit the system + * \param node the current node + */ +static void leave(node_t node) +{ + DEBUG0("Well Guys! I Think it's time for me to quit ;)"); + quit_notify(node, 1); // notify to my successor ( >>> 1 ); + quit_notify(node, -1); // notify my predecessor ( >>> -1); + // TODO ... } /* - * + * \brief Notifies the successor or the predecessor of the current node + * of the departure + * \param node the current node + * \param to 1 to notify the successor, -1 to notify the predecessor + * FIXME: notify both nodes with only one call */ -void find_successor_node(data_node* n_data,m_task_t join_task) //use all data +static void quit_notify(node_t node, int to) { - //get recv data - data_node *recv_data = (data_node*)MSG_task_get_data(join_task); - INFO3("recv_data->id : %i , n_data->id :%i , successor->id :%i",recv_data->id,n_data->id,n_data->fingers[0].id); - //if ((recv_data->id >= n_data->id) && (recv_data->id <= n_data->fingers[0].id)) - if (is_in_interval(recv_data->id,n_data->id,n_data->fingers[0].id)) - { - INFO1("Successor Is %s",n_data->fingers[0].host_name); - //predecessor(recv_data) >>>> n_data - recv_data->pred_host_name = n_data->host_name; - recv_data->pred_id = n_data->id; - recv_data->pred_mailbox = n_data->pred_mailbox; - // successor(recv_data) >>>> n_data.finger[0] - recv_data->fingers_nb = 1; - recv_data->fingers[0].host_name = n_data->fingers[0].host_name; - recv_data->fingers[0].id = n_data->fingers[0].id; - recv_data->fingers[0].mailbox = n_data->fingers[0].mailbox; - // successor(n_data) >>>> recv_sucessor - n_data->fingers[0].id = recv_data->id; - n_data->fingers[0].host_name = recv_data->host_name; - n_data->fingers[0].mailbox = recv_data->mailbox; - // Logs - INFO1("Sending back a Join Request to %s",recv_data->host_name); - MSG_task_set_name(join_task,"Join Response"); - MSG_task_send(join_task,recv_data->mailbox); - } - - else - { - const char* closest_preceding_mailbox = find_closest_preceding(n_data,recv_data->id); - INFO1("Forwarding Join Call to mailbox %s",closest_preceding_mailbox); - MSG_task_send(join_task,closest_preceding_mailbox); - } + /* TODO + task_data_t req_data = xbt_new0(s_task_data_t, 1); + req_data->request_id = node->id; + req_data->successor_id = node->fingers[0].id; + req_data->pred_id = node->pred_id; + req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); + req_data->answer_to = NULL; + const char* task_name = NULL; + const char* to_mailbox = NULL; + if (to == 1) { // notify my successor + to_mailbox = node->fingers[0].mailbox; + INFO2("Telling my Successor %d about my departure via mailbox %s", + node->fingers[0].id, to_mailbox); + req_data->type = TASK_PREDECESSOR_LEAVING; + } + else if (to == -1) { // notify my predecessor + + if (node->pred_id == -1) { + return; + } + + to_mailbox = node->pred_mailbox; + INFO2("Telling my Predecessor %d about my departure via mailbox %s", + node->pred_id, to_mailbox); + req_data->type = TASK_SUCCESSOR_LEAVING; + } + m_task_t task = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data); + //char* mailbox = get_mailbox(to_mailbox); + msg_comm_t comm = MSG_task_isend(task, to_mailbox); + xbt_dynar_push(node->comms, &comm); + */ } -const char* find_closest_preceding(data_node* n_node,int id) +/** + * \brief Makes the current node find the successor node of an id. + * \param node the current node + * \param id the id to find + * \return the id of the successor node, or -1 if the request failed + */ +static int find_successor(node_t node, int id) { - int i; - for(i = n_node->fingers_nb-1; i >= 0 ; i--) - { - if (n_node->fingers[i].id <= id) - return n_node->fingers[i].mailbox; - } - - return n_node->mailbox; // !!!!!!!!!!!!!! + // is my successor the successor? + if (is_in_interval(id, node->id + 1, node->fingers[0].id)) { + return node->fingers[0].id; + } + + // otherwise, ask the closest preceding finger in my table + int closest = closest_preceding_node(node, id); + return remote_find_successor(node, closest, id); } -/* - * Fin successor id : used to fix finger list + +/** + * \brief Asks another node the successor node of an id. + * \param node the current node + * \param ask_to the node to ask to + * \param id the id to find + * \return the id of the successor node, or -1 if the request failed */ -static int find_successor(data_node* n_data, int id) +static int remote_find_successor(node_t node, int ask_to, int id) { - if (is_in_interval(id,n_data->id,n_data->fingers[0].id)) - return n_data->fingers[0].id; - else - return 0; + int successor = -1; + int stop = 0; + char* mailbox = get_mailbox(ask_to); + task_data_t req_data = xbt_new0(s_task_data_t, 1); + req_data->type = TASK_FIND_SUCCESSOR; + req_data->request_id = id; + req_data->answer_to = xbt_strdup(node->mailbox); + req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); + + // send a "Find Successor" request to ask_to_id + m_task_t task_sent = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data); + DEBUG3("Sending a 'Find Successor' request (task %p) to %d for id %d", task_sent, ask_to, id); + MSG_error_t res = MSG_task_send_with_timeout(task_sent, mailbox, TIMEOUT); + + if (res != MSG_OK) { + DEBUG3("Failed to send the 'Find Successor' request (task %p) to %d for id %d", + task_sent, ask_to, id); + MSG_task_destroy(task_sent); + task_data_destroy(req_data); + } + else { + + // receive the answer + DEBUG3("Sent a 'Find Successor' request (task %p) to %d for key %d, waiting for the answer", + task_sent, ask_to, id); + + do { + if (node->comm_receive == NULL) { + m_task_t task_received = NULL; + node->comm_receive = MSG_task_irecv(&task_received, node->mailbox); + } + + res = MSG_comm_wait(node->comm_receive, TIMEOUT); + + if (res != MSG_OK) { + DEBUG2("Failed to receive the answer to my 'Find Successor' request (task %p): %d", + task_sent, res); + stop = 1; + //MSG_comm_destroy(node->comm_receive); + } + else { + m_task_t task_received = MSG_comm_get_task(node->comm_receive); + DEBUG1("Received a task (%p)", task_received); + task_data_t ans_data = MSG_task_get_data(task_received); + + if (task_received != task_sent) { + // this is not the expected answer + handle_task(node, task_received); + } + else { + // this is our answer + DEBUG4("Received the answer to my 'Find Successor' request for id %d (task %p): the successor of key %d is %d", + ans_data->request_id, task_received, id, ans_data->answer_id); + successor = ans_data->answer_id; + stop = 1; + MSG_task_destroy(task_received); + task_data_destroy(req_data); + } + } + node->comm_receive = NULL; + } while (!stop); + } + xbt_free(mailbox); + return successor; } +/** + * \brief Asks another node its predecessor. + * \param node the current node + * \param ask_to the node to ask to + * \return the id of its predecessor node, or -1 if the request failed + * (or if the node does not know its predecessor) + */ +static int remote_get_predecessor(node_t node, int ask_to) +{ + int predecessor_id = -1; + int stop = 0; + char* mailbox = get_mailbox(ask_to); + task_data_t req_data = xbt_new0(s_task_data_t, 1); + req_data->type = TASK_GET_PREDECESSOR; + req_data->answer_to = xbt_strdup(node->mailbox); + req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); + + // send a "Get Predecessor" request to ask_to_id + DEBUG1("Sending a 'Get Predecessor' request to %d", ask_to); + m_task_t task_sent = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data); + MSG_error_t res = MSG_task_send_with_timeout(task_sent, mailbox, TIMEOUT); + + if (res != MSG_OK) { + DEBUG2("Failed to send the 'Get Predecessor' request (task %p) to %d", + task_sent, ask_to); + MSG_task_destroy(task_sent); + task_data_destroy(req_data); + } + else { + + // receive the answer + DEBUG3("Sent 'Get Predecessor' request (task %p) to %d, waiting for the answer on my mailbox '%s'", + task_sent, ask_to, req_data->answer_to); + + do { + if (node->comm_receive == NULL) { // FIXME simplify this + m_task_t task_received = NULL; + node->comm_receive = MSG_task_irecv(&task_received, node->mailbox); + } + + res = MSG_comm_wait(node->comm_receive, TIMEOUT); + + if (res != MSG_OK) { + DEBUG2("Failed to receive the answer to my 'Get Predecessor' request (task %p): %d", + task_sent, res); + stop = 1; + //MSG_comm_destroy(node->comm_receive); + } + else { + m_task_t task_received = MSG_comm_get_task(node->comm_receive); + task_data_t ans_data = MSG_task_get_data(task_received); + + if (task_received != task_sent) { + handle_task(node, task_received); + } + else { + DEBUG3("Received the answer to my 'Get Predecessor' request (task %p): the predecessor of node %d is %d", + task_received, ask_to, ans_data->answer_id); + predecessor_id = ans_data->answer_id; + stop = 1; + MSG_task_destroy(task_received); + task_data_destroy(req_data); + } + } + node->comm_receive = NULL; + } while (!stop); + } -/** Test function */ -MSG_error_t test_all(const char *platform_file, - const char *application_file) + xbt_free(mailbox); + return predecessor_id; +} + +/** + * \brief Returns the closest preceding finger of an id + * with respect to the finger table of the current node. + * \param node the current node + * \param id the id to find + * \return the closest preceding finger of that id + */ +int closest_preceding_node(node_t node, int id) +{ + int i; + for (i = NB_BITS - 1; i >= 0; i--) { + if (is_in_interval(node->fingers[i].id, node->id + 1, id - 1)) { + return node->fingers[i].id; + } + } + return node->id; +} + +/** + * \brief This function is called periodically. It checks the immediate + * successor of the current node. + * \param node the current node + */ +static void stabilize(node_t node) { - MSG_error_t res = MSG_OK; + DEBUG0("Stabilizing node"); - /* MSG_config("workstation/model","KCCFLN05"); */ - { /* Simulation setting */ - MSG_set_channel_number(0); - MSG_create_environment(platform_file); + // get the predecessor of my immediate successor + int candidate_id; + int successor_id = node->fingers[0].id; + if (successor_id != node->id) { + candidate_id = remote_get_predecessor(node, successor_id); + } + else { + candidate_id = node->pred_id; + } + // this node is a candidate to become my new successor + if (candidate_id != -1 + && is_in_interval(candidate_id, node->id + 1, successor_id - 1)) { + set_finger(node, 0, candidate_id); } - { /* Application deployment */ - MSG_function_register("node",node); - MSG_launch_application(application_file); + if (successor_id != node->id) { + remote_notify(node, successor_id, node->id); } - res = MSG_main(); - INFO1("Simulation time %g", MSG_get_clock()); +} + +/** + * \brief Notifies the current node that its predecessor may have changed. + * \param node the current node + * \param candidate_id the possible new predecessor + */ +static void notify(node_t node, int predecessor_candidate_id) { - return res; -} /* end_of_test_all */ + if (node->pred_id == -1 + || is_in_interval(predecessor_candidate_id, node->pred_id + 1, node->id - 1)) { -/** Main function */ -int main(int argc, char *argv[]) + set_predecessor(node, predecessor_candidate_id); + print_finger_table(node); + } + else { + DEBUG1("I don't have to change my predecessor to %d", predecessor_candidate_id); + } +} + +/** + * \brief Notifies a remote node that its predecessor may have changed. + * \param node the current node + * \param notify_id id of the node to notify + * \param candidate_id the possible new predecessor + */ +static void remote_notify(node_t node, int notify_id, int predecessor_candidate_id) { + + task_data_t req_data = xbt_new0(s_task_data_t, 1); + req_data->type = TASK_NOTIFY; + req_data->request_id = predecessor_candidate_id; + req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); + req_data->answer_to = NULL; + + // send a "Notify" request to notify_id + m_task_t task = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data); + DEBUG2("Sending a 'Notify' request (task %p) to %d", task, notify_id); + char* mailbox = get_mailbox(notify_id); + msg_comm_t comm = MSG_task_isend(task, mailbox); + xbt_dynar_push(node->comms, &comm); + xbt_free(mailbox); +} + +/** + * \brief This function is called periodically. + * It refreshes the finger table of the current node. + * \param node the current node + */ +static void fix_fingers(node_t node) { + + DEBUG0("Fixing fingers"); + int i = node->next_finger_to_fix; + int id = find_successor(node, node->id + powers2[i]); + if (id != -1) { + + if (id != node->fingers[i].id) { + set_finger(node, i, id); + print_finger_table(node); + } + node->next_finger_to_fix = (i + 1) % NB_BITS; + } +} + +/** + * \brief This function is called periodically. + * It checks whether the predecessor has failed + * \param node the current node + */ +static void check_predecessor(node_t node) { - MSG_error_t res = MSG_OK; + DEBUG0("Checking whether my predecessor is alive"); + // TODO +} - MSG_global_init(&argc, argv); +/** + * \brief Main function. + */ +int main(int argc, char *argv[]) +{ if (argc < 3) { printf("Usage: %s platform_file deployment_file\n", argv[0]); - printf("example: %s msg_platform.xml msg_deployment.xml\n", argv[0]); + printf("example: %s ../msg_platform.xml chord.xml\n", argv[0]); exit(1); } - res = test_all(argv[1], argv[2]); + + const char* platform_file = argv[1]; + const char* application_file = argv[2]; + + chord_initialize(); + + MSG_global_init(&argc, argv); + MSG_set_channel_number(0); + MSG_create_environment(platform_file); + + MSG_function_register("node", node); + MSG_launch_application(application_file); + + MSG_error_t res = MSG_main(); + INFO1("Simulation time: %g", MSG_get_clock()); + MSG_clean(); if (res == MSG_OK) return 0; else return 1; -} /* end_of_main */ +}