source: doc/papers/IBM_CASCON19/client.cfa@ fca78f1

// 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;
}