} s_node_t, *node_t;
/**
- * Task data
+ * 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 {
- int request_id;
- int request_finger;
- int answer_id;
- const char* answer_to;
- const char* issuer_host_name; // used for logging
- int successor_id; // used when quitting
- int pred_id; // used when quitting
- // FIXME: remove successor_id and pred_id, request_id is enough
+ 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)
+ const char* answer_to; // mailbox to send an answer to
+ const char* issuer_host_name; // used for logging
} s_task_data_t, *task_data_t;
static int powers2[NB_BITS];
// Chord core
static void create(node_t node);
-static void join(node_t node, int known_id);
+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 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
}
/**
- * \brief Turns an id into an equivalent id in [0, NB_KEYS[
+ * \brief Turns an id into an equivalent id in [0, NB_KEYS).
* \param id an id
* \return the corresponding normalized id
*/
* \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
- * FIXME: free the memory
*/
static char* get_mailbox(int node_id)
{
node->fingers[finger_index].id = id;
xbt_free(node->fingers[finger_index].mailbox);
node->fingers[finger_index].mailbox = get_mailbox(id);
- INFO2("My new finger #%d is %d", finger_index, id);
+ DEBUG2("My new finger #%d is %d", finger_index, id);
}
/**
node->pred_mailbox = get_mailbox(predecessor_id);
}
- INFO1("My new predecessor is %d", predecessor_id);
+ DEBUG1("My new predecessor is %d", predecessor_id);
}
/**
{
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;
if (argc == 3) { // first ring
deadline = atof(argv[2]);
create(&node);
+ join_success = 1;
}
else {
int known_id = atoi(argv[2]);
deadline = atof(argv[4]);
// sleep before starting
- INFO1("Let's sleep during %f", sleep_time);
+ DEBUG1("Let's sleep during %f", sleep_time);
MSG_process_sleep(sleep_time);
- INFO0("Hey! Let's join the system.");
+ DEBUG0("Hey! Let's join the system.");
- join(&node, known_id);
+ join_success = join(&node, known_id);
}
- while (MSG_get_clock() < init_time + deadline) {
+ if (join_success) {
+ while (MSG_get_clock() < init_time + deadline) {
- if (node.comm_receive == NULL) {
- task = NULL;
- node.comm_receive = MSG_task_irecv(&task, node.mailbox);
- // FIXME: do not make MSG_task_irecv() calls from several functions
- }
+ 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)) {
+ 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;
+ // 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 {
- // nothing to do: sleep for a while
- MSG_process_sleep(5);
- }
- }
- else {
- // a transfer has occured
+ // a transfer has occured
- MSG_error_t status = MSG_comm_get_status(node.comm_receive);
- MSG_comm_destroy(node.comm_receive);
- node.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.");
+ if (status != MSG_OK) {
+ DEBUG0("Failed to receive a task. Nevermind.");
+ }
+ else {
+ // the task was successfully received
+ handle_task(&node, task_received);
+ }
}
- else {
- // the task was successfully received
- handle_task(&node, task);
+
+ // 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);
}
}
- // 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);
- 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));
+ // 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);
+ xbt_free(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
}
- }
- // 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);
- xbt_free(MSG_task_get_data(task));
- MSG_task_destroy(task);
- MSG_comm_destroy(comm_send);
+ // leave the ring
+ leave(&node);
}
- // leave the ring and stop the simulation
- leave(&node);
+ // stop the simulation
xbt_dynar_free(&node.comms);
xbt_free(node.mailbox);
xbt_free(node.pred_mailbox);
*/
static void handle_task(node_t node, m_task_t task) {
+ DEBUG1("Handling task %p", 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",
+ 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;
+ comm = MSG_task_isend(task, task_data->answer_to);
+ xbt_dynar_push(node->comms, &comm);
+ 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);
- }
- 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 {
+ // 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;
- 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",
+ 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;
+ comm = MSG_task_isend(task, task_data->answer_to);
+ xbt_dynar_push(node->comms, &comm);
+ 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);
- }
-
- 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);
- xbt_free(task_data);
- MSG_task_destroy(task);
- }
-
- 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);
- xbt_free(task_data);
- MSG_task_destroy(task);
- /*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);
- xbt_free(task_data);
- MSG_task_destroy(task);
- /* TODO
- >> notify my new successor
- >> update my table & predecessors table */
+ 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);
+ xbt_free(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);
+ xbt_free(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);
+ xbt_free(task_data);
+ MSG_task_destroy(task);
+ /* TODO
+ >> notify my new successor
+ >> update my table & predecessors table */
+ break;
+
+ default:
+ CRITICAL1("Received an unexpected task: %d", type);
+ //xbt_abort();
}
}
*/
static void create(node_t node)
{
- INFO0("Create a new Chord ring...");
+ DEBUG0("Create a new Chord ring...");
set_predecessor(node, -1); // -1 means that I have no predecessor
print_finger_table(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
*/
-static void join(node_t 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)
- int successor_id;
- do {
- successor_id = remote_find_successor(node, known_id, node->id);
- if (successor_id == -1) {
- INFO0("I really want to join the ring. Let's try again.");
- }
- } while (successor_id == -1);
+ int successor_id = remote_find_successor(node, known_id, node->id);
+ if (successor_id == -1) {
+ DEBUG0("Cannot join the ring.");
+ }
+ else {
+ set_finger(node, 0, successor_id);
+ print_finger_table(node);
+ }
- set_finger(node, 0, successor_id);
- print_finger_table(node);
+ return successor_id != -1;
}
/**
*/
static void leave(node_t node)
{
- INFO0("Well Guys! I Think it's time for me to quit ;)");
+ 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 ...
to_mailbox = node->fingers[0].mailbox;
INFO2("Telling my Successor %d about my departure via mailbox %s",
node->fingers[0].id, to_mailbox);
- task_name = "Predecessor Leaving";
+ req_data->type = TASK_PREDECESSOR_LEAVING;
}
else if (to == -1) { // notify my predecessor
to_mailbox = node->pred_mailbox;
INFO2("Telling my Predecessor %d about my departure via mailbox %s",
node->pred_id, to_mailbox);
- task_name = "Successor Leaving";
+ req_data->type = TASK_SUCCESSOR_LEAVING;
}
- m_task_t task = MSG_task_create(task_name, COMP_SIZE, COMM_SIZE, req_data);
+ 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);
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 = 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 id %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(NULL, COMP_SIZE, COMM_SIZE, req_data);
+ DEBUG3("Sending a 'Find Successor' request (task %p) to %d for id %d", task, ask_to, id);
MSG_error_t res = MSG_task_send_with_timeout(task, mailbox, 50);
if (res != MSG_OK) {
- INFO2("Failed to send the 'Find Successor' request to %d for id %d", ask_to, id);
+ DEBUG2("Failed to send the 'Find Successor' request to %d for id %d", ask_to, id);
MSG_task_destroy(task);
xbt_free(req_data);
}
else {
// receive the answer
- INFO2("Sent a 'Find Successor' request to %d for key %d, waiting for the answer", ask_to, id);
+ DEBUG3("Sent a 'Find Successor' request (task %p) to %d for key %d, waiting for the answer",
+ task, ask_to, id);
do {
if (node->comm_receive == NULL) {
res = MSG_comm_wait(node->comm_receive, 50);
if (res != MSG_OK) {
- INFO1("Failed to receive the answer to my 'Find Successor' request: %d", res);
+ DEBUG2("Failed to receive the answer to my 'Find Successor' request (task %p): %d", task, res);
stop = 1;
// MSG_comm_destroy(node->comm_receive);
}
else {
task = MSG_comm_get_task(node->comm_receive);
- INFO1("Received a task '%s'", MSG_task_get_name(task));
+ task_data_t ans_data = MSG_task_get_data(task);
- if (strcmp(MSG_task_get_name(task), "Find Successor Answer")) {
+ if (ans_data->type != TASK_FIND_SUCCESSOR_ANSWER) {
handle_task(node, task);
}
else {
- INFO2("This is the answer to my 'Find Successor' request: the successor of key %d is %d", id, successor);
- task_data_t ans_data = MSG_task_get_data(task);
+ DEBUG3("Received the answer to my 'Find Successor' request (task %p): the successor of key %d is %d",
+ task, id, successor);
successor = ans_data->answer_id;
stop = 1;
MSG_task_destroy(task);
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 = 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);
+ DEBUG1("Sending a 'Get Predecessor' request to %d", ask_to);
+ m_task_t task = MSG_task_create(NULL, COMP_SIZE, COMM_SIZE, req_data);
MSG_error_t res = MSG_task_send_with_timeout(task, mailbox, 50);
if (res != MSG_OK) {
- INFO1("Failed to send the 'Get Predecessor' request to %d", ask_to);
+ DEBUG1("Failed to send the 'Get Predecessor' request to %d", ask_to);
MSG_task_destroy(task);
xbt_free(req_data);
}
else {
// receive the answer
- INFO2("Sent 'Get Predecessor' request to %d, waiting for the answer on my mailbox '%s'", ask_to, req_data->answer_to);
+ DEBUG2("Sent 'Get Predecessor' request to %d, waiting for the answer on my mailbox '%s'", ask_to, req_data->answer_to);
do {
if (node->comm_receive == NULL) { // FIXME simplify this
res = MSG_comm_wait(node->comm_receive, 50);
if (res != MSG_OK) {
- INFO1("Failed to receive the answer to my 'Get Predecessor' request: %d", res);
+ DEBUG1("Failed to receive the answer to my 'Get Predecessor' request: %d", res);
stop = 1;
// MSG_comm_destroy(node->comm_receive);
}
else {
task = MSG_comm_get_task(node->comm_receive);
- INFO1("Received a task '%s'", MSG_task_get_name(task));
+ task_data_t ans_data = MSG_task_get_data(task);
- if (strcmp(MSG_task_get_name(task), "Get Predecessor Answer")) {
+ if (ans_data->type != TASK_GET_PREDECESSOR_ANSWER) {
handle_task(node, task);
}
else {
- INFO2("This is the answer to my 'Get Predecessor' request: the predecessor of node %d is %d", ask_to, predecessor_id);
- task_data_t ans_data = MSG_task_get_data(task);
+ DEBUG2("Received the answer to my 'Get Predecessor' request: the predecessor of node %d is %d", ask_to, predecessor_id);
predecessor_id = ans_data->answer_id;
stop = 1;
MSG_task_destroy(task);
*/
static void stabilize(node_t node)
{
- INFO0("Stabilizing node");
+ DEBUG0("Stabilizing node");
// get the predecessor of my immediate successor
int candidate_id;
print_finger_table(node);
}
else {
- INFO1("I don't have to change my predecessor to %d", predecessor_candidate_id);
+ DEBUG1("I don't have to change my predecessor to %d", predecessor_candidate_id);
}
}
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());
// send a "Notify" request to notify_id
- INFO1("Sending a 'Notify' request to %d", notify_id);
- m_task_t task = MSG_task_create("Notify", COMP_SIZE, COMM_SIZE, req_data);
+ DEBUG1("Sending a 'Notify' request to %d", notify_id);
+ m_task_t task = MSG_task_create(NULL, 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);
*/
static void fix_fingers(node_t node) {
- INFO0("Fixing fingers");
+ DEBUG0("Fixing fingers");
int i = node->next_finger_to_fix;
int id = find_successor(node, node->id + powers2[i]);
if (id != -1) {
*/
static void check_predecessor(node_t node)
{
- INFO0("Checking whether my predecessor is alive");
+ DEBUG0("Checking whether my predecessor is alive");
// TODO
}
