+++ /dev/null
-/* Copyright (c) 2012, 2014-2016. The SimGrid Team.
- * All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-#include "dht-kademlia.h"
-#include "node.h"
-#include "task.h"
-
-#include "simgrid/msg.h"
-/** @addtogroup MSG_examples
- * <b>kademlia/kademlia.c: Kademlia protocol</b>
- * Implements the Kademlia protocol, using 32 bits identifiers.
- */
-XBT_LOG_NEW_DEFAULT_CATEGORY(msg_kademlia, "Messages specific for this msg example");
-
-/* Main loop for the process */
-static void main_loop(node_t node, double deadline)
-{
- double next_lookup_time = MSG_get_clock() + random_lookup_interval;
- XBT_VERB("Main loop start");
- while (MSG_get_clock() < deadline) {
-
- if (node->receive_comm == NULL) {
- node->task_received = NULL;
- node->receive_comm = MSG_task_irecv(&node->task_received, node->mailbox);
- }
- if (node->receive_comm) {
- if (!MSG_comm_test(node->receive_comm)) {
- /* We search for a pseudo random node */
- if (MSG_get_clock() >= next_lookup_time) {
- random_lookup(node);
- next_lookup_time += random_lookup_interval;
- } else {
- //Didn't get a task: sleep for a while...
- MSG_process_sleep(1);
- }
- } else {
- //There has been a transfer, we need to handle it !
- msg_error_t status = MSG_comm_get_status(node->receive_comm);
- MSG_comm_destroy(node->receive_comm);
- node->receive_comm = NULL;
-
- if (status == MSG_OK) {
- xbt_assert((node->task_received != NULL), "We received an incorrect task");
- handle_task(node, node->task_received);
- } else {
- xbt_assert((MSG_comm_get_task(node->receive_comm) == NULL), "Comm failed but received a task.");
- XBT_DEBUG("Nevermind, the communication has failed.");
- }
- }
- } else {
- //Didn't get a comm: sleep.
- MSG_process_sleep(1);
- }
- }
- //Cleanup the receiving communication.
- if (node->receive_comm != NULL) {
- if (MSG_comm_test(node->receive_comm) && MSG_comm_get_status(node->receive_comm) == MSG_OK) {
- task_free(MSG_comm_get_task(node->receive_comm));
- }
- MSG_comm_destroy(node->receive_comm);
- }
-}
-
-/** @brief Node function
- * @param my node ID
- * @param the ID of the person I know in the system (or not)
- * @param Time before I leave the system because I'm bored
- */
-static int node(int argc, char *argv[])
-{
- unsigned int join_sucess = 1;
- double deadline;
- xbt_assert(argc == 3 || argc == 4, "Wrong number of arguments");
- /* Node initialization */
- unsigned int id = strtoul(argv[1], NULL, 0);
- node_t node = node_init(id);
-
- if (argc == 4) {
- XBT_INFO("Hi, I'm going to join the network with id %s", node->mailbox);
- unsigned int id_known = strtoul(argv[2], NULL, 0);
- join_sucess = join(node, id_known);
- deadline = strtod(argv[3], NULL);
- } else {
- deadline = strtod(argv[2], NULL);
- XBT_INFO("Hi, I'm going to create the network with id %s", node->mailbox);
- node_routing_table_update(node, node->id);
- }
- if (join_sucess) {
- XBT_VERB("Ok, I'm joining the network with id %s", node->mailbox);
- //We start the main loop
- main_loop(node, deadline);
- } else {
- XBT_INFO("I couldn't join the network :(");
- }
- XBT_DEBUG("I'm leaving the network");
- XBT_INFO("%d/%d FIND_NODE have succeeded", node->find_node_success, node->find_node_success + node->find_node_failed);
- node_free(node);
-
- return 0;
-}
-
-/**
- * @brief Tries to join the network
- * @param node node data
- * @param id_known id of the node I know in the network.
- */
-unsigned int join(node_t node, unsigned int id_known)
-{
- answer_t node_list;
- msg_error_t status;
- unsigned int trial = 0;
- unsigned int i;
- unsigned int answer_got = 0;
-
- /* Add the guy we know to our routing table and ourselves. */
- node_routing_table_update(node, node->id);
- node_routing_table_update(node, id_known);
-
- /* First step: Send a "FIND_NODE" request to the node we know */
- send_find_node(node, id_known, node->id);
- do {
- if (node->receive_comm == NULL) {
- node->task_received = NULL;
- node->receive_comm = MSG_task_irecv(&node->task_received, node->mailbox);
- }
- if (node->receive_comm) {
- if (MSG_comm_test(node->receive_comm)) {
- status = MSG_comm_get_status(node->receive_comm);
- MSG_comm_destroy(node->receive_comm);
- node->receive_comm = NULL;
- if (status == MSG_OK) {
- XBT_DEBUG("Received an answer from the node I know.");
- answer_got = 1;
- //retrieve the node list and ping them.
- task_data_t data = MSG_task_get_data(node->task_received);
- xbt_assert((data != NULL), "Null data received");
- if (data->type == TASK_FIND_NODE_ANSWER) {
- node_contact_t contact;
- node_list = data->answer;
- xbt_dynar_foreach(node_list->nodes, i, contact) {
- node_routing_table_update(node, contact->id);
- }
- task_free(node->task_received);
- } else {
- handle_task(node, node->task_received);
- }
- } else {
- trial++;
- }
- } else {
- MSG_process_sleep(1);
- }
- } else {
- MSG_process_sleep(1);
- }
- } while (answer_got == 0 && trial < max_join_trials);
- /* Second step: Send a FIND_NODE to a a random node in buckets */
- unsigned int bucket_id = routing_table_find_bucket(node->table, id_known)->id;
- for (i = 0; ((bucket_id > i) || (bucket_id + i) <= identifier_size) && i < JOIN_BUCKETS_QUERIES; i++) {
- if (bucket_id > i) {
- unsigned int id_in_bucket = get_id_in_prefix(node->id, bucket_id - i);
- find_node(node, id_in_bucket, 0);
- }
- if (bucket_id + i <= identifier_size) {
- unsigned int id_in_bucket = get_id_in_prefix(node->id, bucket_id + i);
- find_node(node, id_in_bucket, 0);
- }
- }
- return answer_got;
-}
-
-/** @brief Send a request to find a node in the node routing table.
- * @param node our node data
- * @param id_to_find the id of the node we are trying to find
- */
-unsigned int find_node(node_t node, unsigned int id_to_find, unsigned int count_in_stats)
-{
- unsigned int i = 0;
- unsigned int queries;
- unsigned int answers;
- unsigned int destination_found = 0;
- unsigned int nodes_added = 0;
- double time_beginreceive;
- double timeout;
- double global_timeout = MSG_get_clock() + find_node_global_timeout;
- unsigned int steps = 0;
-
- xbt_assert((id_to_find >= 0), "Id supplied incorrect");
-
- /* First we build a list of who we already know */
- answer_t node_list = node_find_closest(node, id_to_find);
- xbt_assert((node_list != NULL), "node_list incorrect");
-
- XBT_DEBUG("Doing a FIND_NODE on %08x", id_to_find);
-
- msg_error_t status;
-
- /* Ask the nodes on our list if they have information about the node we are trying to find */
- do {
- answers = 0;
- queries = send_find_node_to_best(node, node_list);
- nodes_added = 0;
- timeout = MSG_get_clock() + find_node_timeout;
- steps++;
- time_beginreceive = MSG_get_clock();
- do {
- if (node->receive_comm == NULL) {
- node->task_received = NULL;
- node->receive_comm = MSG_task_irecv(&node->task_received, node->mailbox);
- }
- if (node->receive_comm) {
- if (MSG_comm_test(node->receive_comm)) {
- status = MSG_comm_get_status(node->receive_comm);
- MSG_comm_destroy(node->receive_comm);
- node->receive_comm = NULL;
- if (status == MSG_OK) {
- xbt_assert((node->task_received != NULL), "Invalid task received");
- //Figure out if we received an answer or something else
- task_data_t data = MSG_task_get_data(node->task_received);
- xbt_assert((data != NULL), "No data in the task");
-
- //Check if what we have received is what we are looking for.
- if (data->type == TASK_FIND_NODE_ANSWER && data->answer->destination_id == id_to_find) {
- //Handle the answer
- node_routing_table_update(node, data->sender_id);
- node_contact_t contact;
- xbt_dynar_foreach(node_list->nodes, i, contact) {
- node_routing_table_update(node, contact->id);
- }
- answers++;
-
- nodes_added = answer_merge(node_list, data->answer);
- XBT_DEBUG("Received an answer from %s (%s) with %ld nodes on it",
- data->answer_to, data->issuer_host_name, xbt_dynar_length(data->answer->nodes));
-
- task_free(node->task_received);
- } else {
- handle_task(node, node->task_received);
- //Update the timeout if we didn't have our answer
- timeout += MSG_get_clock() - time_beginreceive;
- time_beginreceive = MSG_get_clock();
- }
- }
- } else {
- MSG_process_sleep(1);
- }
- } else {
- MSG_process_sleep(1);
- }
- } while (MSG_get_clock() < timeout && answers < queries);
- destination_found = answer_destination_found(node_list);
- } while (!destination_found && (nodes_added > 0 || answers == 0) && MSG_get_clock() < global_timeout
- && steps < MAX_STEPS);
- if (destination_found) {
- if (count_in_stats)
- node->find_node_success++;
- if (queries > 4)
- XBT_VERB("FIND_NODE on %08x success in %d steps", id_to_find, steps);
- node_routing_table_update(node, id_to_find);
- } else {
- if (count_in_stats) {
- node->find_node_failed++;
- XBT_VERB("%08x not found in %d steps", id_to_find, steps);
- }
- }
- answer_free(node_list);
- return destination_found;
-}
-
-/** @brief Pings a node in the system to see if it is online.
- * @param node Our node data
- * @param id_to_ping the id of a node we want to see if it is online.
- * @return if the ping succeded or not.
- */
-unsigned int ping(node_t node, unsigned int id_to_ping)
-{
- char mailbox[MAILBOX_NAME_SIZE];
- snprintf(mailbox,MAILBOX_NAME_SIZE, "%d", id_to_ping);
-
- double timeout = MSG_get_clock() + ping_timeout;
-
- msg_task_t ping_task = task_new_ping(node->id, node->mailbox, MSG_host_get_name(MSG_host_self()));
- msg_task_t task_received = NULL;
-
- XBT_VERB("PING %08x", id_to_ping);
-
- //Check that we aren't trying to ping ourselves
- if (id_to_ping == node->id) {
- return 1;
- }
-
- /* Sending the ping task */
- MSG_task_dsend(ping_task, mailbox, task_free_v);
- do {
- task_received = NULL;
- msg_error_t status =
- MSG_task_receive_with_timeout(&task_received, node->mailbox, ping_timeout);
- if (status == MSG_OK) {
- xbt_assert((task_received != NULL), "Invalid task received");
- //Checking if it's what we are waiting for or not.
- task_data_t data = MSG_task_get_data(task_received);
- xbt_assert((data != NULL), "didn't receive any data...");
- if (data->type == TASK_PING_ANSWER && id_to_ping == data->sender_id) {
- XBT_VERB("Ping to %s succeeded", mailbox);
- node_routing_table_update(node, data->sender_id);
- task_free(task_received);
- return 1; // Destination found, ping succeeded!
- } else {
- //If it's not our answer, we answer the query anyway.
- handle_task(node, task_received);
- }
- }
- } while (MSG_get_clock() < timeout);
-
- if (MSG_get_clock() >= timeout) {
- XBT_DEBUG("Ping to %s has timeout.", mailbox);
- return 0;
- }
- XBT_DEBUG("It seems that %s is offline...", mailbox);
- return -1;
-}
-
-/** @brief Does a pseudo-random lookup for someone in the system
- * @param node caller node data
- */
-void random_lookup(node_t node)
-{
- unsigned int id_to_look = RANDOM_LOOKUP_NODE; //Totally random.
- /* TODO: Use some pseudorandom generator like RngStream. */
- XBT_DEBUG("I'm doing a random lookup");
- find_node(node, id_to_look, 1);
-}
-
-/** @brief Send a "FIND_NODE" to a node
- * @param node sender node data
- * @param id node we are querying
- * @param destination node we are trying to find.
- */
-void send_find_node(node_t node, unsigned int id, unsigned int destination)
-{
- char mailbox[MAILBOX_NAME_SIZE];
- /* Gets the mailbox to send to */
- get_node_mailbox(id, mailbox);
- /* Build the task */
- msg_task_t task = task_new_find_node(node->id, destination, node->mailbox, MSG_host_get_name(MSG_host_self()));
- /* Send the task */
- xbt_assert((task != NULL), "Trying to send a NULL task.");
- MSG_task_dsend(task, mailbox, task_free_v);
- XBT_VERB("Asking %s for its closest nodes", mailbox);
-}
-
-/**
- * Sends to the best "kademlia_alpha" nodes in the "node_list" array a "FIND_NODE" request, to ask them for their best nodes
- */
-unsigned int send_find_node_to_best(node_t node, answer_t node_list)
-{
- unsigned int i = 0;
- unsigned int j = 0;
- unsigned int destination = node_list->destination_id;
- node_contact_t node_to_query;
- while (j < kademlia_alpha && i < node_list->size) {
- /* We need to have at most "kademlia_alpha" requests each time, according to the protocol */
- /* Gets the node we want to send the query to */
- node_to_query = xbt_dynar_get_as(node_list->nodes, i, node_contact_t);
- if (node_to_query->id != node->id) { /* No need to query ourselves */
- send_find_node(node, node_to_query->id, destination);
- j++;
- }
- i++;
- }
- return i;
-}
-
-/** @brief Handles an incoming received task */
-void handle_task(node_t node, msg_task_t task)
-{
- task_data_t data = MSG_task_get_data(task);
- xbt_assert((data != NULL), "Received NULL data");
- //Adding/updating the guy to our routing table
- node_routing_table_update(node, data->sender_id);
- switch (data->type) {
- case TASK_FIND_NODE:
- handle_find_node(node, data);
- break;
- case TASK_FIND_NODE_ANSWER:
- XBT_DEBUG("Received a wrong answer for a FIND_NODE");
- break;
- case TASK_PING:
- handle_ping(node, data);
- break;
- default:
- break;
- }
- task_free(task);
-}
-
-/** @brief Handles the answer to an incoming "find_node" task */
-void handle_find_node(node_t node, task_data_t data)
-{
- XBT_VERB("Received a FIND_NODE from %s (%s), he's trying to find %08x",
- data->answer_to, data->issuer_host_name, data->destination_id);
- //Building the answer to the request
- answer_t answer = node_find_closest(node, data->destination_id);
- //Building the task to send
- msg_task_t task = task_new_find_node_answer(node->id, data->destination_id, answer, node->mailbox,
- MSG_host_get_name(MSG_host_self()));
- //Sending the task
- MSG_task_dsend(task, data->answer_to, task_free_v);
-}
-
-/** @brief handles the answer to a ping */
-void handle_ping(node_t node, task_data_t data)
-{
- XBT_VERB("Received a PING request from %s (%s)", data->answer_to, data->issuer_host_name);
- //Building the answer to the request
- msg_task_t task = task_new_ping_answer(node->id, data->answer_to, MSG_host_get_name(MSG_host_self()));
-
- MSG_task_dsend(task, data->answer_to, task_free_v);
-}
-
-/** @brief Main function */
-int main(int argc, char *argv[])
-{
- MSG_init(&argc, argv);
-
- /* Check the arguments */
- xbt_assert(argc > 2, "Usage: %s platform_file deployment_file\n\tExample: %s msg_platform.xml msg_deployment.xml\n",
- argv[0], argv[0]);
-
- const char *platform_file = argv[1];
- const char *deployment_file = argv[2];
-
- MSG_create_environment(platform_file);
- MSG_function_register("node", node);
- MSG_launch_application(deployment_file);
-
- msg_error_t res = MSG_main();
-
- XBT_INFO("Simulated time: %g", MSG_get_clock());
-
- return res != MSG_OK;
-}
