PROGRAM FOR SUM OF ARRAY USING SPIN LOCK

#include<stdio.h>
#include<sys/types.h>
#include<sys/shm.h>
#include<sys/ipc.h>
#include \"headsem.h\"
#include \"headfork.h\"

main()
{
    int tempsum=0,np,a[10];
    int *lock1,*finalsum;
    int id,n,i,sid1,sid2;

    sid1=shmget(IPC_PRIVATE,10,0666|IPC_CREAT);
    lock1=(int *)shmat(sid1,0,0);

    sid2=shmget(IPC_PRIVATE,10,0666|IPC_CREAT);
    finalsum=(int *)shmat(sid2,0,0);

    *finalsum=0;

    printf(\"Enter the size of array :\");
    scanf(\"%d\",&n);

    printf(\"Enter the array elements :\");
    for(i=0;i<n;i++)
        scanf(\"%d\",&a[i]);

    printf(\"Enter the no.of proc :\");
    scanf(\"%d\",&np);

    lock_init(lock1);

    id=p_fork(np);

    for(i=id;i<n;i+=np)
        tempsum+=a[i];

    locksem(lock1);

    *finalsum+=tempsum;

    unlock(lock1);

    p_join(np,id);
    printf(\"Sum : %d\",*finalsum);
}