1 /* Copyright (c) 2016-2019. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
8 #include "simgrid/s4u.hpp"
13 constexpr double MAX_SIMULATION_TIME = 1000;
14 constexpr double PERIODIC_STABILIZE_DELAY = 20;
15 constexpr double PERIODIC_FIX_FINGERS_DELAY = 120;
16 constexpr double PERIODIC_CHECK_PREDECESSOR_DELAY = 120;
17 constexpr double PERIODIC_LOOKUP_DELAY = 10;
18 constexpr double SLEEP_DELAY = 4.9999;
24 extern std::default_random_engine generator;
26 /* Types of tasks exchanged between nodes. */
27 enum e_message_type_t {
29 FIND_SUCCESSOR_ANSWER,
31 GET_PREDECESSOR_ANSWER,
36 PREDECESSOR_ALIVE_ANSWER
41 e_message_type_t type; // type of message
42 std::string issuer_host_name; // used for logging
43 int request_id = -1; // id (used by some types of messages)
44 int request_finger = 1; // finger parameter (used by some types of messages)
45 int answer_id = -1; // answer (used by some types of messages)
46 simgrid::s4u::Mailbox* answer_to = nullptr; // mailbox to send an answer to (if any)
48 explicit ChordMessage(e_message_type_t type)
49 : type(type), issuer_host_name(simgrid::s4u::this_actor::get_host()->get_name())
53 static void destroy(void* message);
58 double start_time_ = -1;
59 double deadline_ = -1;
62 int pred_id_ = -1; // predecessor id
63 simgrid::s4u::Mailbox* mailbox_; // my mailbox
64 std::vector<int> fingers_; // finger table,(fingers[0] is my successor)
65 int next_finger_to_fix; // index of the next finger to fix in fix_fingers()
68 explicit Node(std::vector<std::string> args);
69 Node(const Node&) = delete;
70 Node& operator=(const Node&) = delete;
71 void join(int known_id);
76 void setFinger(int finger_index, int id);
78 void printFingerTable();
80 void setPredecessor(int predecessor_id);
81 void checkPredecessor();
82 int remoteGetPredecessor(int ask_to);
83 int closestPrecedingFinger(int id);
84 int findSuccessor(int id);
85 int remoteFindSuccessor(int ask_to, int id);
87 void notify(int predecessor_candidate_id);
88 void remoteNotify(int notify_id, int predecessor_candidate_id);
90 void handleMessage(ChordMessage* message);
94 simgrid::s4u::this_actor::sleep_for(start_time_);
95 if (known_id_ == -1) {
96 setPredecessor(-1); // -1 means that I have no predecessor
105 void* data = nullptr;
106 double now = simgrid::s4u::Engine::get_clock();
107 double next_stabilize_date = start_time_ + PERIODIC_STABILIZE_DELAY;
108 double next_fix_fingers_date = start_time_ + PERIODIC_FIX_FINGERS_DELAY;
109 double next_check_predecessor_date = start_time_ + PERIODIC_CHECK_PREDECESSOR_DELAY;
110 double next_lookup_date = start_time_ + PERIODIC_LOOKUP_DELAY;
111 simgrid::s4u::CommPtr comm_receive = nullptr;
112 while ((now < (start_time_ + deadline_)) && now < MAX_SIMULATION_TIME) {
113 if (comm_receive == nullptr)
114 comm_receive = mailbox_->get_async(&data);
115 while ((now < (start_time_ + deadline_)) && now < MAX_SIMULATION_TIME && not comm_receive->test()) {
116 // no task was received: make some periodic calls
117 if (now >= next_stabilize_date) {
119 next_stabilize_date = simgrid::s4u::Engine::get_clock() + PERIODIC_STABILIZE_DELAY;
120 } else if (now >= next_fix_fingers_date) {
122 next_fix_fingers_date = simgrid::s4u::Engine::get_clock() + PERIODIC_FIX_FINGERS_DELAY;
123 } else if (now >= next_check_predecessor_date) {
125 next_check_predecessor_date = simgrid::s4u::Engine::get_clock() + PERIODIC_CHECK_PREDECESSOR_DELAY;
126 } else if (now >= next_lookup_date) {
128 next_lookup_date = simgrid::s4u::Engine::get_clock() + PERIODIC_LOOKUP_DELAY;
130 // nothing to do: sleep for a while
131 simgrid::s4u::this_actor::sleep_for(SLEEP_DELAY);
133 now = simgrid::s4u::Engine::get_clock();
136 if (data != nullptr) {
137 ChordMessage* message = static_cast<ChordMessage*>(data);
138 handleMessage(message);
139 comm_receive = nullptr;
142 now = simgrid::s4u::Engine::get_clock();
144 if (comm_receive != nullptr) {
145 if (comm_receive->test())
146 delete static_cast<ChordMessage*>(data);
148 comm_receive->cancel();