paper3—Algorithm1-Engine-Trigger-on-FCD—temp

//source code: /run/media/root/E6B2798BB279614B/.../PAPER/paper-3/twin-engine-trigger-code/server-client-pthread-c

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Description: when FCD start, this algorithm will run as a deamon

normterm: normal termination;

normterm=0, SMD is not normal termination;

normterm=1, SMD is normal termination;

smdtime: time of receiving heartbeat from SMD last;

selftime: the most current time of FCD being active;

initconn: Initial connection from SMD to FCD;

initconn=1, initial value is 1;

downtime: suppose server restart time is 30s;

select selftime from fcd_state_table where id=1;

downtime=currenttime - selftime;

update fcd_state_table set selftime=currenttime where id=1;

PROCEDURE: MAIN

socket();

bind();

listen();

while true do

accept(); //waiting for connect from SMD

pthread_create(THREAD);

done

END PROCEDURE

PROCEDURE: THREAD

receive guestname from SMD;

select normterm from user_table where username=guestname;

select processid from process_table where username=guestname and state=active and exectime≈current;

while true do //communication between FCD & SMD

select smdtime from user_table where username=guestname;

period=-1; //used to determine whether SMD access FCD continuously

if receive heartbeat from SMD then

period=currenttime - smdtime;

end if

update user_table set smdtime=currenttime where username=guestname;

if 0< period< 8 or initconn then //normal visits

send heartbeat to SMD;

send information for current process to SMD;

initconn=0;

end if

if receive finish from SMD then //normal termination

update user_table set normterm=1 where username=guestname;

exit; //guest finished his tasks

end if

//server restart, process is not normal end

//after disconnect, SMD reconnect FCD

if downtime > 30 and !normterm or receive reconnect from SMD then

FCD receive current process information from SMD;

update correlative tables where processid=processid;

end if

sleep 1s;

done

END PROCEDURE