//if already failed, return 1. else return 0
int Membership::failMember(std::string ip_str, int timeStamp){
membersLock.lock();
bool exist = false;
int position = 0;
for(int i=0; i<members.size(); i++){
if( members[i].ip_str.compare( ip_str )==0 && members[i].timeStamp == timeStamp ){
exist = true;
position = i;
break;
}
}
if(exist){
MemberUpdateMsg msg(MSG_LEAVE, members[position]);
pushMsgToFileSysQueue(msg);
members.erase( members.begin()+position );
}
membersLock.unlock();
checkLeader();
return !exist;
}
/*!
* Selects or deselects the agent on the given slot.
* \param agentNo
* \param addToGroup True if agent is added to the selection.
* \return True if agent has been selected or deselected.
*/
bool SquadSelection::selectAgent(size_t agentNo, bool addToGroup) {
if (isAgentSelectable(agentNo)) {
// saves the current selection to check if it changes
size_t oldSelection = selected_agents_;
if (addToGroup) {
// Add/remove to the group
selected_agents_ ^= 1 << agentNo;
// check if leader was deselected
checkLeader(agentNo);
} else {
selected_agents_ = 1 << agentNo;
leader_ = agentNo;
}
return (oldSelection != selected_agents_);
}
return false;
}
void Membership::detectThread()
{
/*
WHILE LOOP
roundId++
randomly select one node
send ping message
sleep(1)
see msgQueue, search ack
if(ack)
cout<<alive
sleep(4)
continue
send ping message to random K nodes (call spreadMessage())
sleep(4)
see msgQueue, search ack
if(ack)
cout<<alive
continue
if(!ack)
cout<<fail
delete node
send fail message to other nodes
continue
*/
bool flagFail = false;
Node failedNode;
while(!killDetectingThread)
{
roundId = (roundId+1)%255;
if (roundId % 5 == 0)
{
checkLeader();
}
logFile<< std::endl << "Detection Thread - Round: "<< roundId << " ------------" << std::endl;
logFile<<printMember();
if(members.size() < 2)
{
usleep(5 * MAX_LATENCY);
flagFail = false;
continue;
}
int select = rand()%(members.size()-1) + 1;
Node theNode = members[select];
if (flagFail == true)
{
theNode = failedNode;
}
Message msg;
msg.type = MSG_PING;
msg.TTL = 0;
msg.roundId = roundId;
ipString2Char4(theNode.ip_str, msg.carrierAdd);
msg.timeStamp = 0;
logFile<<"detectThread: checking alive or not for "<<theNode.ip_str<<" "<<theNode.timeStamp<<std::endl;
sendUDP(sockfd, theNode.ip_str, port, (char*)&msg, sizeof(Message));
bool acked = false;
if (queueSize() > 10){
std::cout << "Warning!!! queueSize = " << queueSize() << std::endl;
}
usleep(MAX_LATENCY);
msgQueueLock.lock();
acked = ackMsgQueue();
msgQueueLock.unlock();
static int count = 0;
if(acked){
logFile<<"detectThread: node alive: "<<theNode.ip_str<<" "<<theNode.timeStamp<<std::endl;
flagFail = false;
usleep(4 * MAX_LATENCY);
continue;
}
logFile<<"Hey!!! Node "<<theNode.ip_str<<" did not respond the first time!" << std::endl;
msg.type = MSG_PIGGY;
msg.TTL = 0;
spreadMessage(msg,3);
usleep(4 * MAX_LATENCY);
msgQueueLock.lock();
acked = ackMsgQueue();
msgQueueLock.unlock();
if(acked){
logFile<<"detectThread: second round found node alive: "<<theNode.ip_str<<" "<<theNode.timeStamp<<std::endl;
flagFail = false;
continue;
}
else{
logFile<< "detectThread: No ack received: node failed: "<<theNode.ip_str<<" "<<theNode.timeStamp<<std::endl;
if (flagFail == true)
{
logFile<< "detectThread: No ack received: node failed: "<<theNode.ip_str<<" "<<theNode.timeStamp<<std::endl;
failMember(theNode.ip_str, theNode.timeStamp);
Message failMsg;
failMsg.type = MSG_FAIL;
failMsg.roundId = roundId;
ipString2Char4(theNode.ip_str, failMsg.carrierAdd);
failMsg.timeStamp = theNode.timeStamp;
failMsg.TTL = 3;
spreadMessage(failMsg);
flagFail = false;
}
else
{
logFile<< "detectThread: Robust 2: It is alive: "<<theNode.ip_str<<" "<<theNode.timeStamp<<std::endl;
failedNode = theNode;
flagFail = true;
}
continue;
}
}
}
/*!
* Deselects an agent. Called when an agent died.
* \param agentNo
*/
void SquadSelection::deselectAgent(size_t agentNo) {
selected_agents_ &= ~(1 << agentNo);
// check if leader was deselected
checkLeader(agentNo);
}
