# include <stdio.h>
# include <math.h>
# include "/usr/include/sys/types.h"
# include "/usr/include/sys/shm.h"
# include "/usr/include/sys/ipc.h"
# include "/usr/include/sys/sem.h"
# include "forkjoin.h"
# include "sharedlib.h"
# include "spinlock.h"int main()
{
    int arr[100];
    int arrSize;        //Size of arrayint iCount;        //Counter Variableint id;            //Process IDint nProc=3;        //number of Processesfloat sum=0;
    
    float *deviation,*avg;  // Shared Variablesint *lock;        // Shared Variable for Spinlockint shmidavg,shmidlock,shmiddeviation;    // Shmid for Shared Variables
    
    printf("Enter the Size of an Array :");
    scanf("%d",&arrSize);

    for(iCount=0;iCount<arrSize;iCount++)
    {
        printf("Enter arr[%d] :",iCount);
        scanf("%d",&arr[iCount]);
    }

    /* Allocate Shared memory */

    avg=(float*)sshared(sizeof(float),&shmidavg);
    deviation=(float*)sshared(sizeof(float),&shmiddeviation);
    lock=(int*)sshared(sizeof(int),&shmidlock);

    spin_lock_init(lock);        // Spin Lock Initialization
    *avg=0;

    id=process_fork(nProc);        // Forking Processes/* Partial Sum using Loop Spliting */
for(iCount=id;iCount<arrSize;iCount=iCount+nProc)
    {
        sum = sum + arr[iCount];
    }

    spin_lock(lock);
        /* Critical Region */

        *avg = *avg + ( sum /arrSize);    // Calculate Average from Partial Sums
    spin_unlock(lock);

    /*
    ---------------------------------------------------------------------------
    Barrier Should be here, So that all Processes have to wait until Final
    Average is Calculated.
    ---------------------------------------------------------------------------
    */

    
    sum=0;
    /* Calculate Sum(Xi - Mean) Using Loop Spliting */
for(iCount=id;iCount<arrSize;iCount=iCount+nProc)
    {        
        sum = sum + pow(((float)arr[iCount] - *avg),2);
    }
    
    spin_lock(lock);
        /* Critical Region */

        *deviation = *deviation + (sum / arrSize-1); // Calculate Final Deviation
    spin_unlock(lock);

    
    process_join(nProc,id);        // Joining the Process

    *deviation=sqrt(*deviation);
    printf("Deviation : %f\n",*deviation);

    /* Cleaning the Shared Region */

    cleanup_memory(&shmidavg);
    cleanup_memory(&shmidlock);
    cleanup_memory(&shmiddeviation);    
    return 0;
}


/* Output

[divyen@localhost pp-tw3]$ cc -o Prog01 -lm Prog01.c
[divyen@localhost pp-tw3]$ ./Prog01
Enter the Size of an Array :5
Enter arr[0] :10
Enter arr[1] :20
Enter arr[2] :30
Enter arr[3] :40
Enter arr[4] :50
Deviation : 19.580603

*/