#define NUM_THREADS 5

void *thread( void *t_id ) {
        int i;
        for ( i = 0; i < 200; ++i ) {
                pthread_mutex_lock( &data.mutex );
                ++data.value;
                printf( "thread %d: data value = %d\n",
                        t_id, data.value );
                pthread_mutex_unlock( &data.mutex );
        }
	pthread_exit( NULL );
}