#include <stdio.h>
#include <pthread.h>


int main()
{
    int i, data[5], sum;
    pthread_t tid[5];
    extern void *addfive(void *arg);

    for (i = 0; i < 5; i++) {
        data[i] = i * 5;
        pthread_create(&tid[i], NULL, addfive, &data[i]);
    }

    sum = 0;
    for (i = 0; i < 5; i++) {
        pthread_join(tid[i], NULL);  /* (wait for termination) */
        sum += data[i];
    }

    printf("%d\n", sum);

    return(0);
}


void *addfive(void *arg)
{
    int i = *(int *)arg;
    int j, sum = 0;
    for (j = 0; j < 5; j++)
        sum += i + j;
    *(int *)arg = sum;
    return(NULL);
}


/*

    also mentioned:

        pthread_exit() -- exit this thread (as an alternative to returning
            from the thread function) -- directly analogous to processes'
            calling exit() rather than returning from main().  (Whereas if
            you call the actual exit() instead of pthread_exit(), you will
            terminate the whole process, i.e. all threads!)

        pthread_cancel() -- kill another thread by tid

 */