// Original
void sum_many_async(int[] inputs, lambda_t callback);

// Target
int  sum_many      (int[] inputs);

//==================================

int  sum_many(int[] inputs) {
	// setup required data
	int result;
	semaphore_t sem = { 0 };

	// call async function
	sum_many_async( inputs, (int sum) {
		result = sum;
		V(sem);
	});

	// wait for result
	P(sem);

	// return
	return result;
}


int sum_many_block(int[] inputs);
int sum_many      (int[] inputs);

//==================================

struct request_t {
	int[] inputs;
	int result;
	semaphore_t sem = { 0 };
};

void * call_sum_many_block(void * args) {
	request_t * req = (request_t *) args;
	req->result = sum_many_block(req->inputs);
	V(req->sem);
}

int  sum_many(int[] inputs) {
	// setup required data
	request_t req = { inputs };

	// create thread to
	pthread_t thrd;
	int err = pthread_fork(&thrd, 0p, call_sum_many_block, &req);
	handle(err);

	// wait
	P(req.sem);

	// Cleanup pthread
	err = pthread_join(&thrd, 0p);
	handle(err);

	// get result
	return req.result;
}