for (ut = uttable; ut < &(uttable[MAX_THREAD]);ut++)
        {
        	if (ut->i_am_waiting_for == current){
        		ut->state = T_RUNNABLE;
        	}

        }



int  uthred_join(int tid){

	uthread_p ut;
	uthread_p thread_waiting_for;
	int found = 0;
	/* Check if tid parameter exist in thread pool */

	for (ut = uttable; ut < &(uttable[MAX_THREAD]);ut++)
	{
		if (ut->tid == tid){
			found = 1;
			thread_waiting_for = ut;
		}
	}
	if (found == 0){
		return -1;
	}
	/* check if waited thread already exited */
	if (thread_waiting_for->state == T_FREE){
		return 0; //exit immidietly
	}

	/*thread not exited. start waiting */
	current->i_am_waiting_for = thread_waiting_for;
	current->state = T_SLEEPING;




	return 0;

}