thread_start.c

void * thread_start(void *arg) {
    /* init vars */
    
    /* unpack arg */
    
    while (data->finished == 0) {
        int barrier_result;
        double** temp;
        
        /* for each column. Only run columns the thread_num
            is assigned to */
        for (column_count = thread_num; column_count < dim - 1; column_count+=threads) {
            int row_count = 1;
                    
            innerloopcounter++;
            
            for (;row_count < dim - 1; row_count++) {
                /* manipulate value */
            }
        }
        
        /* barrier */
        barrier_result = pthread_barrier_wait(barrier);
        
        /* for only one thread swap the source & target */
        if (barrier_result == PTHREAD_BARRIER_SERIAL_THREAD) {
            temp = data->source;
            data->source = data->target;
            data->target = temp;
            data->changed = 0;
        }
        
        pthread_barrier_wait(barrier);
        
    }
    
    return 0;
}