participant_subservice.cpp

#pragma once
#include <iostream>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <net/if.h>
#include <stdlib.h>

#include "socket.cpp"
#include "information_subservice.cpp"
#include "election_subservice.cpp"
#include "discovery_subservice.cpp"

#define PORT 4000
#define EXIT_PORT 4001
#define KEEPALIVE_PORT 4002
#define MAX_MISSED_KEEPALIVES 3
#define MAX_MISSED_DISCOVERY 10
#define KEEPALIVE_INTERVAL 1
#define BROADCAST_IP "255.255.255.255"

using namespace std;

string manager_ip = "", manager_mac = "", manager_hostname = "";
bool manager_changed = false;
extern bool manager;
bool keep_monitoring = true;

void becomeManager(){
  manager = true;
}

void listenForServicePackets() {
  Socket ptcp_socket;
  int send_res, recv_res;
  string mac_addr = getMacAddress();
  string hostname = getSelfHostname();

  cerr << "Entrando na listenForServicePackets" << endl;

  // ptcp_socket.setTimeoutOpt();
  ptcp_socket.listenPort(PORT);

  while(true) {
    // if (manager) {
    //   continue;
    // }
    // Listen for packets sent by the manager to PORT

    recv_res = ptcp_socket.receiveMessage();
    if (recv_res > 0) {
      // cerr << "[P] Manager (IP " << ptcp_socket.getSenderIP() << ") asked: " << ptcp_socket.getBuffer() << endl;

      // Get manager infos
      string received_ip = ptcp_socket.getSenderIP();
      string buffer = ptcp_socket.getBuffer();
      string received_mac =  buffer.substr(0,17);
      string received_hostname = buffer.substr(17);

      if (manager && received_ip != getSelfIP()) {
        // cerr << received_ip << " is another manager" << endl;
        // manager = false;
        // startManagerElection();
      }

      if (manager_ip != received_ip || manager_mac != received_mac || manager_hostname != received_hostname) {
        manager_ip = received_ip;
        manager_mac = received_mac;
        manager_hostname = received_hostname;
        manager_changed = true;
      }

      // Answers the packet received
      send_res = ptcp_socket.sendMessageToSender(mac_addr + hostname);
      if (send_res < 0)
        cerr << "[P] ERROR sendto" << endl;
    }
  }
  ptcp_socket.closeSocket();
  cerr << "[P] Exiting listenForServicePackets thread" << endl;
}

void monitorateManagerStatus() {
  Socket ptcp_socket, ptcp_socket2;
  int send_res, recv_res, missed_keepalives = 0, manager_discovery_count = 0;
  string mac_addr = getMacAddress();
  string hostname = getSelfHostname();

  // Wait for the discovery of a manager
  while(manager_ip == "" && !manager) {
    // cout << "[P] Manager not known yet" << endl;
    manager_discovery_count++;
    cerr << "[P] Manager not found. Count: " << manager_discovery_count << endl;
    if(manager_discovery_count >= MAX_MISSED_DISCOVERY) {
      startManagerElection();
      MachinesManager::Instance().createMachine(getSelfIP(), mac_addr, hostname);
      MachinesManager::Instance().setNewManager(getSelfIP());
      addParticipantsFromTable();
    }
    sleep(1);
  }

  while(true) {
    if (manager) {
      continue;
    }
    missed_keepalives = 0;
    while(keep_monitoring) {
      ptcp_socket.setSendAddr(manager_ip, KEEPALIVE_PORT);

      // Send packet querying the manager's status
      send_res = ptcp_socket.sendMessage(mac_addr + hostname);
      if (send_res < 0)
        cerr << ("[P] ERROR sendto") << endl;

      recv_res = ptcp_socket.receiveMessage();
      if (recv_res < 0) {
        missed_keepalives++;
        cerr << "[P] Manager didn't answer. Missed keepalives: " << missed_keepalives << endl;
        if (missed_keepalives >= MAX_MISSED_KEEPALIVES) {
          // ptcp_socket2.setBroadcastOpt();
	        // ptcp_socket2.setSendAddr(BROADCAST_IP, PORT);
          // cout << "[P] Starting a Manager election" << endl;
          startManagerElection();
          // if (newManager == true) {becomeManager()} // IDEA
          keep_monitoring = false;
        }
      }
      else {
        // cout << "[P] Manager " << IP << " answered: " << ptcp_socket.getBuffer() << endl;
        missed_keepalives = 0;
      }

      sleep(KEEPALIVE_INTERVAL);
    }
  }
  ptcp_socket.closeSocket();
  cerr << "[P] Exiting monitorateManagerStatus thread" << endl;
}

void sendExitPacket(){
  Socket exit_socket;
  exit_socket.setSendAddr(manager_ip, EXIT_PORT);
  //Send exit message to specified exit port
  int exit_message = exit_socket.sendMessage("sleep service exit");
}