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@rachejazz
Last active Jul 25, 2020
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This is process 1: He is annoying and will only stop once it receives a signal from his neighbour.
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
/*If he causes any problem, do a `kill -9 <Neighbour ID> on a separate terminal.*/
int shmid;
pid_t *shmptr;
void __gcov_flush(void);//check in gcc sources gcc/gcov-io.h for the prototype, in case it creates problems.
void sig1_handler(volatile sig_atomic_t usr_sig)
{
signal(usr_sig, SIG_IGN);
printf("Received instructions %u\nDumping neighbour's fight logs.\n I am happy you erred\n",usr_sig);
__gcov_flush();
shmdt(shmptr);
shmctl(shmid, IPC_RMID, NULL);
exit(1);
}
void sig2_handler(volatile sig_atomic_t usr_sig)
{
signal(usr_sig, SIG_IGN);
printf("Received instructions %u\nDumping neighbour's complaints logs.\n I am kidnapped.\n",usr_sig);
__gcov_flush();
shmdt(shmptr);
shmctl(shmid, IPC_RMID, NULL);
exit(2);
}
void sig3_handler(volatile sig_atomic_t usr_sig)
{
signal(usr_sig, SIG_IGN);
printf("Received instructions %u\nDumping neighbour's quarrel logs.\n I am killed\n",usr_sig);
__gcov_flush();
shmdt(shmptr);
shmctl(shmid, IPC_RMID, NULL);
exit(3);
}
void sig4_handler(volatile sig_atomic_t usr_sig)
{
signal(usr_sig, SIG_IGN);
printf("Received instruction %u\ndumping error logs.\n I am spared\n",usr_sig);
__gcov_flush();
shmdt(shmptr);
shmctl(shmid, IPC_RMID, NULL);
exit(4);
}
void main(int argc, char **argv[])
{
int i;
pid_t pid=getpid();
key_t keygen;
if (signal(SIGUSR1, sig1_handler)==SIG_ERR){
printf("Error1. interrupt and try again\n");
//signal(SIGINT, sigdf_handler);
exit(0);
}
if (signal(SIGINT, sig2_handler)==SIG_ERR){
printf("Error2. interrupt and try again\n");
exit(0);
}
if (signal(SIGQUIT, sig3_handler)==SIG_ERR){
printf("Error3. interrupt and try again\n");
exit(0);
}
if (signal(SIGUSR2, sig4_handler)==SIG_ERR){
printf("Error4. interrupt and try again\n");
exit(0);
}
/*This is the shared memory created to be given access to the neighbbour 2.
The signal arrives here through the following route*/
keygen=ftok(".",'s');
shmid=shmget(keygen, sizeof(pid_t), IPC_CREAT | 0666);
shmptr=(pid_t *) shmat(shmid, NULL, 0);
*shmptr=pid;
for(i=0; ;i++){
printf("I am Neighbour ID:%d:%dI like to annoy you\n",pid,i);
sleep(2);}
}
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