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;
27 simgrid::s4u::Host* host = nullptr;
30 static simgrid::xbt::Extension<simgrid::s4u::Host, HostChord> EXTENSION_ID;
32 explicit HostChord(simgrid::s4u::Host* ptr) : host(ptr) {}
33 HostChord(const HostChord&) = delete;
34 HostChord& operator=(const HostChord&) = delete;
38 /* Types of tasks exchanged between nodes. */
39 enum e_message_type_t {
41 FIND_SUCCESSOR_ANSWER,
43 GET_PREDECESSOR_ANSWER,
48 PREDECESSOR_ALIVE_ANSWER
53 e_message_type_t type; // type of message
54 std::string issuer_host_name; // used for logging
55 int request_id = -1; // id (used by some types of messages)
56 int request_finger = 1; // finger parameter (used by some types of messages)
57 int answer_id = -1; // answer (used by some types of messages)
58 simgrid::s4u::Mailbox* answer_to = nullptr; // mailbox to send an answer to (if any)
60 explicit ChordMessage(e_message_type_t type)
61 : type(type), issuer_host_name(simgrid::s4u::this_actor::get_host()->get_name())
65 static void destroy(void* message);
70 double start_time_ = -1;
71 double deadline_ = -1;
74 int pred_id_ = -1; // predecessor id
75 simgrid::s4u::Mailbox* mailbox_; // my mailbox
76 std::vector<int> fingers_; // finger table,(fingers[0] is my successor)
77 int next_finger_to_fix; // index of the next finger to fix in fix_fingers()
80 explicit Node(std::vector<std::string> args);
81 Node(const Node&) = delete;
82 Node& operator=(const Node&) = delete;
83 void join(int known_id);
88 void setFinger(int finger_index, int id);
90 void printFingerTable();
92 void setPredecessor(int predecessor_id);
93 void checkPredecessor();
94 int remoteGetPredecessor(int ask_to);
95 int closestPrecedingFinger(int id);
96 int findSuccessor(int id);
97 int remoteFindSuccessor(int ask_to, int id);
99 void notify(int predecessor_candidate_id);
100 void remoteNotify(int notify_id, int predecessor_candidate_id);
102 void handleMessage(ChordMessage* message);
106 simgrid::s4u::this_actor::sleep_for(start_time_);
107 if (known_id_ == -1) {
108 setPredecessor(-1); // -1 means that I have no predecessor
117 void* data = nullptr;
118 double now = simgrid::s4u::Engine::get_clock();
119 double next_stabilize_date = start_time_ + PERIODIC_STABILIZE_DELAY;
120 double next_fix_fingers_date = start_time_ + PERIODIC_FIX_FINGERS_DELAY;
121 double next_check_predecessor_date = start_time_ + PERIODIC_CHECK_PREDECESSOR_DELAY;
122 double next_lookup_date = start_time_ + PERIODIC_LOOKUP_DELAY;
123 simgrid::s4u::CommPtr comm_receive = nullptr;
124 while ((now < (start_time_ + deadline_)) && now < MAX_SIMULATION_TIME) {
125 if (comm_receive == nullptr)
126 comm_receive = mailbox_->get_async(&data);
127 while ((now < (start_time_ + deadline_)) && now < MAX_SIMULATION_TIME && not comm_receive->test()) {
128 // no task was received: make some periodic calls
129 if (now >= next_stabilize_date) {
131 next_stabilize_date = simgrid::s4u::Engine::get_clock() + PERIODIC_STABILIZE_DELAY;
132 } else if (now >= next_fix_fingers_date) {
134 next_fix_fingers_date = simgrid::s4u::Engine::get_clock() + PERIODIC_FIX_FINGERS_DELAY;
135 } else if (now >= next_check_predecessor_date) {
137 next_check_predecessor_date = simgrid::s4u::Engine::get_clock() + PERIODIC_CHECK_PREDECESSOR_DELAY;
138 } else if (now >= next_lookup_date) {
140 next_lookup_date = simgrid::s4u::Engine::get_clock() + PERIODIC_LOOKUP_DELAY;
142 // nothing to do: sleep for a while
143 simgrid::s4u::this_actor::sleep_for(SLEEP_DELAY);
145 now = simgrid::s4u::Engine::get_clock();
148 if (data != nullptr) {
149 ChordMessage* message = static_cast<ChordMessage*>(data);
150 handleMessage(message);
151 comm_receive = nullptr;
154 now = simgrid::s4u::Engine::get_clock();
156 if (comm_receive != nullptr) {
157 if (comm_receive->test())
158 delete static_cast<ChordMessage*>(data);
160 comm_receive->cancel();