From 875a9034a2f6a1dc9498b921e19fa30093fba9a3 Mon Sep 17 00:00:00 2001 From: thiery Date: Thu, 16 Dec 2010 18:16:34 +0000 Subject: [PATCH 1/1] Chord finally beats the deadlocks git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@9279 48e7efb5-ca39-0410-a469-dd3cf9ba447f --- .gitignore | 1 - examples/msg/chord/chord.c | 561 ++++++++++------------------------- examples/msg/chord/chord.xml | 2 +- 3 files changed, 161 insertions(+), 403 deletions(-) diff --git a/.gitignore b/.gitignore index b20603e3b1..13d1c53ecb 100644 --- a/.gitignore +++ b/.gitignore @@ -260,7 +260,6 @@ tools/gras/gras_stub_generator tools/tesh/tesh examples/msg/tracing/categories examples/msg/tracing/ms -examples/msg/chord/chord teshsuite/simdag/platforms/is_router_test examples/msg/masterslave/masterslave_cluster examples/simdag/simdag_tracing diff --git a/examples/msg/chord/chord.c b/examples/msg/chord/chord.c index f148ca54b2..dc7c1cfb48 100644 --- a/examples/msg/chord/chord.c +++ b/examples/msg/chord/chord.c @@ -35,7 +35,8 @@ typedef struct node { 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() - xbt_dynar_t comms; // current communications pending + msg_comm_t comm_receive; // current communication to receive + xbt_dynar_t comms; // current communications being sent } s_node_t, *node_t; /** @@ -65,6 +66,7 @@ static void set_predecessor(node_t node, int predecessor_id); // process functions static int node(int argc, char *argv[]); +static void handle_task(node_t node, m_task_t task); // Chord core static void create(node_t node); @@ -81,23 +83,6 @@ static void fix_fingers(node_t node); static void check_predecessor(node_t node); static void quit_notify(node_t node, int to); -// not implemented yet -//static void remote_move_keys(node_t node, int take_from_id); - -// deprecated -/* -static void bootstrap(node_t node, int known_id); -static int find_predecessor(node_t node, int id); -static int remote_find_predecessor(node_t node, int ask_to_id, int id); -static int remote_closest_preceding_finger(int ask_to_id, int id); -static void notify_predecessors(node_t node); -static void initialize_finger_table(node_t data, int known_id); -static void update_finger_table(node_t node, int candidate_id, int finger_index); -static void remote_update_finger_table(node_t node, int ask_to_id, int candidate_id, int finger_index); -static void notify_node_joined(node_t node, int new_node_id); -static void remote_notify_node_joined(node_t node, int notify_id); -*/ - static void chord_initialize(void) { // compute the powers of 2 once for all @@ -231,9 +216,7 @@ int node(int argc, char *argv[]) double init_time = MSG_get_clock(); m_task_t task = NULL; msg_comm_t comm_send = NULL; - msg_comm_t comm_receive = NULL; int i; - char* mailbox = NULL; double deadline; double next_stabilize_date = init_time + 10; double next_fix_fingers_date = init_time + 10; @@ -276,15 +259,18 @@ int node(int argc, char *argv[]) while ((index = MSG_comm_testany(node.comms)) != -1) { comm_send = xbt_dynar_get_as(node.comms, index, msg_comm_t); xbt_dynar_remove_at(node.comms, index, &comm_send); + DEBUG3("Communication %p is finished with status %d, dynar size is now %lu", + comm_send, MSG_comm_get_status(comm_send), xbt_dynar_length(node.comms)); MSG_comm_destroy(comm_send); } - if (comm_receive == NULL) { + if (node.comm_receive == NULL) { task = NULL; - comm_receive = MSG_task_irecv(&task, node.mailbox); + node.comm_receive = MSG_task_irecv(&task, node.mailbox); + // FIXME: do not make MSG_task_irecv() calls from several functions } - if (!MSG_comm_test(comm_receive)) { + if (!MSG_comm_test(node.comm_receive)) { // no task was received: make some periodic calls if (MSG_get_clock() >= next_stabilize_date) { @@ -301,116 +287,22 @@ int node(int argc, char *argv[]) } else { // nothing to do: sleep for a while - MSG_process_sleep(5); + MSG_process_sleep(1); } } else { // a transfer has occured - MSG_error_t status = MSG_comm_get_status(comm_receive); - MSG_comm_destroy(comm_receive); - comm_receive = NULL; + MSG_error_t status = MSG_comm_get_status(node.comm_receive); + MSG_comm_destroy(node.comm_receive); + node.comm_receive = NULL; if (status != MSG_OK) { INFO0("Failed to receive a task. Nevermind."); } else { // the task was successfully received - const char* task_name = MSG_task_get_name(task); - task_data_t task_data = (task_data_t) MSG_task_get_data(task); - - if (!strcmp(task_name, "Find Successor")) { - INFO2("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->answer_id = node.fingers[0].id; - MSG_task_set_name(task, "Find Successor Answer"); - INFO3("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_send = MSG_task_isend(task, task_data->answer_to); - xbt_dynar_push(node.comms, &comm_send); - } - else { - // otherwise, forward the request to the closest preceding finger in my table - int closest = closest_preceding_node(&node, task_data->request_id); - INFO2("Forwarding the 'Find Successor' request for id %d to my closest preceding finger %d", - task_data->request_id, closest); - mailbox = get_mailbox(closest); - comm_send = MSG_task_isend(task, mailbox); - xbt_dynar_push(node.comms, &comm_send); - xbt_free(mailbox); - } - } - - else if (!strcmp(task_name, "Get Predecessor")) { - INFO1("Receiving a 'Get Predecessor' request from %s", task_data->issuer_host_name); - task_data->answer_id = node.pred_id; - MSG_task_set_name(task, "Get Predecessor Answer"); - INFO2("Sending back a 'Get Predecessor Answer' to %s: my predecessor is %d", - task_data->issuer_host_name, task_data->answer_id); - comm_send = MSG_task_isend(task, task_data->answer_to); - xbt_dynar_push(node.comms, &comm_send); - } - /* - else if (!strcmp(task_name, "Find Predecessor")) { - INFO2("Receiving a 'Find Predecessor' Request from %s for id %d", task_data->issuer_host_name, task_data->request_id); - // am I the predecessor? - if (is_in_interval(task_data->request_id, node.id + 1, node.fingers[0].id)) { - task_data->answer_id = node.id; - MSG_task_set_name(task, "Find Predecessor Answer"); - INFO3("Sending back a 'Find Predecessor' Answer to %s: the predecessor 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); - INFO2("Forwarding 'Find Predecessor' 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); - } - } - */ - - /* - else if (!strcmp(task_name, "Notify Node Joined")) { - // someone may be my new neighboor - INFO1("Receiving a 'Notify Node Joine' request from %s", task_data->issuer_host_name); - notify_node_joined(&node, task_data->request_id); - } - else if (!strcmp(task_name, "Update Finger")) { - // someone is telling me that he may be my new finger - INFO1("Receiving an 'Update Finger' request from %s", task_data->issuer_host_name); - update_finger_table(&node, task_data->request_id, task_data->request_finger); - } - */ - else if (!strcmp(task_name, "Notify")) { - // someone is telling me that he may be my new predecessor - INFO1("Receiving a 'Notify' request from %s", task_data->issuer_host_name); - notify(&node, task_data->request_id); - } - else if (!strcmp(task_name, "Predecessor Leaving")) { - // my predecessor is about to quit - INFO1("Receiving a 'Predecessor Leaving' message from %s", task_data->issuer_host_name); - // modify my predecessor - set_predecessor(&node, task_data->pred_id); - /*TODO : - >> notify my new predecessor - >> send a notify_predecessors !! - */ - } - else if (!strcmp(task_name, "Successor Leaving")) { - // my successor is about to quit - INFO1("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->successor_id); - /* TODO - >> notify my new successor - >> update my table & predecessors table */ - } + handle_task(&node, task); } } } @@ -426,6 +318,82 @@ int node(int argc, char *argv[]) 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 + */ +static void handle_task(node_t node, m_task_t task) { + + msg_comm_t comm = NULL; + char* mailbox = NULL; + const char* task_name = MSG_task_get_name(task); + task_data_t task_data = (task_data_t) MSG_task_get_data(task); + + if (!strcmp(task_name, "Find Successor")) { + INFO2("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->answer_id = node->fingers[0].id; + MSG_task_set_name(task, "Find Successor Answer"); + comm = MSG_task_isend(task, task_data->answer_to); + xbt_dynar_push(node->comms, &comm); + INFO3("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); + } + else { + // otherwise, forward the request to the closest preceding finger in my table + int closest = closest_preceding_node(node, task_data->request_id); + INFO2("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); + } + } + + else if (!strcmp(task_name, "Get Predecessor")) { + INFO1("Receiving a 'Get Predecessor' request from %s", task_data->issuer_host_name); + task_data->answer_id = node->pred_id; + MSG_task_set_name(task, "Get Predecessor Answer"); + comm = MSG_task_isend(task, task_data->answer_to); + xbt_dynar_push(node->comms, &comm); + INFO3("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); + } + + else if (!strcmp(task_name, "Notify")) { + // someone is telling me that he may be my new predecessor + INFO1("Receiving a 'Notify' request from %s", task_data->issuer_host_name); + notify(node, task_data->request_id); + } + + else if (!strcmp(task_name, "Predecessor Leaving")) { + // my predecessor is about to quit + INFO1("Receiving a 'Predecessor Leaving' message from %s", task_data->issuer_host_name); + // modify my predecessor + set_predecessor(node, task_data->pred_id); + /*TODO : + >> notify my new predecessor + >> send a notify_predecessors !! + */ + } + + else if (!strcmp(task_name, "Successor Leaving")) { + // my successor is about to quit + INFO1("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->successor_id); + /* TODO + >> notify my new successor + >> update my table & predecessors table */ + } +} + /** * \brief Initializes the current node as the first one of the system. * \param node the current node @@ -460,78 +428,6 @@ static void join(node_t node, int known_id) print_finger_table(node); } -/** - * \brief Notifies the current node that a node has just joined the network. - * \param node the current node - * \param new_node_id id of the new node in the network - */ -/* -static void notify_node_joined(node_t node, int new_node_id) -{ - INFO1("A new node %d has joined the network, let's see if it is a neighboor", new_node_id); - if (is_in_interval(new_node_id, node->id + 1, node->fingers[0].id - 1)) { - // new_node_id is my new successor - set_finger(node, 0, new_node_id); - bootstrap(node, new_node_id); - } - - if (is_in_interval(new_node_id, node->pred_id + 1, node->id - 1)) { - // new_node_id is my new predecessor - set_predecessor(node, new_node_id); - bootstrap(node, new_node_id); - } -} -*/ - -/** - * \brief Notifies a remote node that the current node has just joined - * the network. - * \param node the current node - * \param notify_id id of the remote node to notify - */ -/* -static void remote_notify_node_joined(node_t node, int notify_id) -{ - task_data_t req_data = xbt_new0(s_task_data_t, 1); - req_data->request_id = node->id; - req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); - - // send a "Notify" request to notify_id - INFO2("Sending a 'Notify' request to %d because I have joined the network with id %d", notify_id, node->id); - m_task_t task = MSG_task_create("Notify", COMP_SIZE, COMM_SIZE, req_data); - 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 Let the current node send queries to fill in its own finger table. -* \param node the current node -* \param ask_to_id id of a node to send queries to -*/ -/* -static void bootstrap(node_t node, int ask_to_id) -{ - INFO0("Filling my finger table"); - int i, pred_id, succ_id; - int pow = 1; - - for (i = 0; i < NB_BITS; i++) - { - pred_id = remote_find_successor(node, ask_to_id, pow); - do { - succ_id = pred_id; - pred_id = remote_find_predecessor(node, pred_id, pred_id); - } while (pred_id >= pow); - - pow = pow << 1; - set_finger(node, i, succ_id); - } -} -*/ - /** * \brief Makes the current node quit the system * \param node the current node @@ -586,121 +482,6 @@ static void quit_notify(node_t node, int to) xbt_dynar_push(node->comms, &comm); } -/* - * \brief Initializes my finger table, knowing the id of a node already in the system. - * \param node the current node - * \param known_id id of a node already in the system - */ -/* -static void initialize_finger_table(node_t node, int known_id) -{ - int my_id = node->id; - int i; - int pow = 1; // 2^i - - INFO0("Initializing my finger table..."); - - // ask known_id who is my immediate successor - node->fingers[0].id = remote_find_successor(node, known_id, my_id + 1); - node->fingers[0].mailbox = get_mailbox(node->fingers[0].id); - - // find all other fingers - for (i = 0; i < NB_BITS - 1; i++) { - - pow = pow << 1; // equivalent to pow = pow * 2 - if (is_in_interval(my_id + pow, my_id, node->fingers[i].id - 1)) { - // I already have the info for this finger - node->fingers[i + 1].id = node->fingers[i].id; - } - else { - // I don't have the info, ask the only guy I know - node->fingers[i + 1].id = remote_find_successor(node, known_id, my_id + pow); - } - node->fingers[i + 1].mailbox = get_mailbox(node->fingers[i + 1].id); - } - - node->pred_id = find_predecessor(node, node->id); - node->pred_mailbox = get_mailbox(node->pred_id); - - INFO0("Finger table initialized!"); - print_finger_table(node); -} -*/ - -/** - * \brief Notifies some nodes that the current node may have became their finger. - * \param node the current node, which has just joined the system - */ -/* -static void notify_predecessors(node_t node) -{ - int i, pred_id; - int pow = 1; - for (i = 0; i < NB_BITS; i++) { - // find the closest node whose finger #i can be me - pred_id = find_predecessor(node, node->id - pow + 1); // note: no "+1" in the article! - if (pred_id != node->id) { - remote_update_finger_table(node, pred_id, node->id, i); - } - pow = pow << 1; // pow = pow * 2 - } -} -*/ - -/** - * \brief Tells the current node that a node may have became its new finger. - * \param node the current node - * \param candidate_id id of the node that may be a new finger of the current node - * \param finger_index index of the finger to update - */ -/* -static void update_finger_table(node_t node, int candidate_id, int finger_index) -{ - int pow = 1; - int i; - for (i = 0; i < finger_index; i++) { - pow = pow << 1; - } - - // if (is_in_interval(candidate_id, node->id + pow, node->fingers[finger_index].id - 1)) { - if (is_in_interval(candidate_id, node->id, node->fingers[finger_index].id - 1)) { -// INFO3("Candidate %d is between %d and %d!", candidate_id, node->id + pow, node->fingers[finger_index].id - 1); - // candidate_id is my new finger - set_finger(node, finger_index, candidate_id); - print_finger_table(node); - - if (node->pred_id != node->id) { // FIXME: is this necessary? - // my predecessor may be concerned too - remote_update_finger_table(node, node->pred_id, candidate_id, finger_index); - } - } -} -*/ - -/** - * \brief Tells a remote node that a node may have became its new finger. - * \param ask_to_id id of the remote node to update - * \param candidate_id id of the node that may be a new finger of the remote node - * \param finger_index index of the finger to update - */ -/* -static void remote_update_finger_table(node_t node, int ask_to_id, int candidate_id, int finger_index) -{ - task_data_t req_data = xbt_new0(s_task_data_t, 1); - req_data->request_id = candidate_id; - req_data->request_finger = finger_index; - req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); - - // send a "Update Finger" request to ask_to_id - INFO3("Sending an 'Update Finger' request to %d: his finger #%d may be %d now", ask_to_id, finger_index, candidate_id); - m_task_t task = MSG_task_create("Update Finger", COMP_SIZE, COMM_SIZE, req_data); - char* mailbox = get_mailbox(ask_to_id); - msg_comm_t comm = MSG_task_isend(task, mailbox); - xbt_dynar_push(node->comms, &comm); - xbt_free(mailbox); -} -*/ - /** * \brief Makes the current node find the successor node of an id. * \param node the current node @@ -729,35 +510,53 @@ static int find_successor(node_t node, int id) static int remote_find_successor(node_t node, int ask_to, int id) { int successor = -1; - s_task_data_t req_data; - char* mailbox = bprintf("%s Find Successor", node->mailbox); - req_data.request_id = id; - req_data.answer_to = mailbox; - req_data.issuer_host_name = MSG_host_get_name(MSG_host_self()); + int received_answer = 0; + task_data_t req_data = xbt_new0(s_task_data_t, 1); + req_data->request_id = id; + req_data->answer_to = node->mailbox; + req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); // send a "Find Successor" request to ask_to_id INFO2("Sending a 'Find Successor' request to %d for key %d", ask_to, id); - m_task_t task = MSG_task_create("Find Successor", COMP_SIZE, COMM_SIZE, &req_data); + m_task_t task = MSG_task_create("Find Successor", COMP_SIZE, COMM_SIZE, req_data); MSG_error_t res = MSG_task_send_with_timeout(task, get_mailbox(ask_to), 200); + if (res == MSG_OK) { // receive the answer - task = NULL; - res = MSG_task_receive_with_timeout(&task, req_data.answer_to, 200); + INFO2("Sent a 'Find Successor' request to %d for key %d, waiting for the answer", ask_to, id); - if (res == MSG_OK) { + do { + if (node->comm_receive == NULL) { + task = NULL; + node->comm_receive = MSG_task_irecv(&task, node->mailbox); + } - task_data_t ans_data; - ans_data = MSG_task_get_data(task); - successor = ans_data->answer_id; - INFO2("Received the answer to my 'Find Successor' request: the successor of key %d is %d", id, successor); - } - } + res = MSG_comm_wait(node->comm_receive, 50); - if (res != MSG_OK) { - INFO2("My 'Find Successor' request to node %d for key %d has failed", ask_to, id); + if (res != MSG_OK) { + INFO1("Failed to receive the answer: %d", res); + } + else { + task = MSG_comm_get_task(node->comm_receive); + INFO1("Received a task '%s'", MSG_task_get_name(task)); + + if (strcmp(MSG_task_get_name(task), "Find Successor Answer")) { + handle_task(node, task); + } + else { + task_data_t ans_data = MSG_task_get_data(task); + successor = ans_data->answer_id; + received_answer = 1; + INFO2("This is the answer to my 'Find Successor' request: the successor of key %d is %d", id, successor); + } + MSG_comm_destroy(node->comm_receive); + node->comm_receive = NULL; +// MSG_task_destroy(task); + } + } while (!received_answer); } - xbt_free(mailbox); + return successor; } @@ -771,94 +570,54 @@ static int remote_find_successor(node_t node, int ask_to, int id) static int remote_get_predecessor(node_t node, int ask_to) { int predecessor_id = -1; - s_task_data_t req_data; - char* mailbox = bprintf("%s Get Predecessor", node->mailbox); - req_data.answer_to = mailbox; - req_data.issuer_host_name = MSG_host_get_name(MSG_host_self()); + int received_answer = 0; + task_data_t req_data = xbt_new0(s_task_data_t, 1); + req_data->answer_to = node->mailbox; + req_data->issuer_host_name = MSG_host_get_name(MSG_host_self()); // send a "Get Predecessor" request to ask_to_id INFO1("Sending a 'Get Predecessor' request to %d", ask_to); - m_task_t task = MSG_task_create("Get Predecessor", COMP_SIZE, COMM_SIZE, &req_data); - MSG_error_t res = MSG_task_send_with_timeout(task, get_mailbox(ask_to), 20); + m_task_t task = MSG_task_create("Get Predecessor", COMP_SIZE, COMM_SIZE, req_data); + MSG_error_t res = MSG_task_send_with_timeout(task, get_mailbox(ask_to), 200); if (res == MSG_OK) { // receive the answer - task = NULL; - res = MSG_task_receive_with_timeout(&task, req_data.answer_to, 20); - - if (res == MSG_OK) { + INFO2("Sent 'Get Predecessor' request to %d, waiting for the answer on my mailbox '%s'", ask_to, req_data->answer_to); - task_data_t ans_data; - ans_data = MSG_task_get_data(task); - predecessor_id = ans_data->answer_id; - INFO2("Received the answer to my 'Get Predecessor' request: the predecessor of node %d is %d", ask_to, predecessor_id); - } - } + do { + if (node->comm_receive == NULL) { // FIXME simplify this + task = NULL; + node->comm_receive = MSG_task_irecv(&task, node->mailbox); + } - if (res != MSG_OK) { - INFO1("My 'Get Predecessor' request to node %d has failed", ask_to); - } + res = MSG_comm_wait(node->comm_receive, 50); - xbt_free(mailbox); - return predecessor_id; -} - -/** - * \brief Makes the current node find the predecessor node of an id. - * \param node the current node - * \param id the id to find - * \return the id of the predecessor node - */ -/* -static int find_predecessor(node_t node, int id) -{ - if (node->id == node->fingers[0].id) { - // I am the only node in the system - return node->id; - } + if (res != MSG_OK) { + INFO1("Failed to receive the answer: %d", res); + } + else { + task = MSG_comm_get_task(node->comm_receive); + INFO1("Received a task '%s'", MSG_task_get_name(task)); - if (is_in_interval(id, node->id + 1, node->fingers[0].id)) { - return node->id; + if (strcmp(MSG_task_get_name(task), "Get Predecessor Answer")) { + handle_task(node, task); + } + else { + task_data_t ans_data = MSG_task_get_data(task); + predecessor_id = ans_data->answer_id; + received_answer = 1; + INFO2("This is the answer to my 'Get Predecessor' request: the predecessor of node %d is %d", ask_to, predecessor_id); + } + MSG_comm_destroy(node->comm_receive); + node->comm_receive = NULL; +// MSG_task_destroy(task); + } + } while (!received_answer); } - int ask_to = closest_preceding_node(node, id); - return remote_find_predecessor(node, ask_to, id); -} -*/ -/** - * \brief Asks another node the predecessor 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 predecessor node - */ -/* -static int remote_find_predecessor(node_t node, int ask_to, int id) -{ - s_task_data_t req_data; - char* mailbox = bprintf("%s Find Predecessor", node->mailbox); - req_data.request_id = id; - req_data.answer_to = mailbox; - req_data.issuer_host_name = MSG_host_get_name(MSG_host_self()); - - // send a "Find Predecessor" request to ask_to - INFO2("Sending a 'Find Predecessor' request to %d for key %d", ask_to, id); - m_task_t task = MSG_task_create("Find Predecessor", COMP_SIZE, COMM_SIZE, &req_data); - MSG_task_send(task, get_mailbox(ask_to)); - - // receive the answer - task = NULL; - MSG_task_receive(&task, req_data.answer_to); - task_data_t ans_data; - ans_data = MSG_task_get_data(task); - int predecessor = ans_data->answer_id; - xbt_free(mailbox); - INFO2("Received the answer to my 'Find Predecessor' request: the predecessor of key %d is %d", id, predecessor); - - return predecessor; + return predecessor_id; } -*/ /** * \brief Returns the closest preceding finger of an id diff --git a/examples/msg/chord/chord.xml b/examples/msg/chord/chord.xml index e235ac710c..e7aaa8a296 100644 --- a/examples/msg/chord/chord.xml +++ b/examples/msg/chord/chord.xml @@ -43,7 +43,7 @@ - + -- 2.20.1