nilResultAfterTimeOut

Result.m

id nilResultAfterTimeOut(int64_t timeoutInNanoSeconds, ResultBlock block) {
    dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
    dispatch_time_t timeoutTime = dispatch_time(DISPATCH_TIME_NOW, timeoutInNanoSeconds);
    __block id result = nil;
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    
    dispatch_async(queue, ^{
        result = block();
        dispatch_semaphore_signal(semaphore);
    });
    
    dispatch_semaphore_wait(semaphore, timeoutTime);
    return result;
}

// Examples

    id result = nilResultAfterTimeOut(1 * NSEC_PER_SEC, ^id{
        sleep(2);
        return @5;
    }); // returns nil
    
    id result = nilResultAfterTimeOut(3 * NSEC_PER_SEC, ^id{
        sleep(2);
        return @5;
    }); // returns @5