event-driven

In a redis datastore I have a list of keys, I want to iterate over that list of keys and get those values from redis. The catch is I am using an event driven language, javascript via node.js If javascript were procedural I could do this function getAll(callback) { var list = redis.lrange(lrange('mykey', 0, -1); for ( var i = 0; i < list.length; i+= 1 ) { list[i] = redis.hgetall(list[i]); } callback(list); } But, I cannot, therefor.. I do this? function getAll(callback) { redis.lrange('mykey', 0, -1, function(err, reply) { // convert reply into messages var list = []; var index = -1; var

What is event-driven programming and has event-driven programming anything to do with threading? I came to this question reading about servers and how they handle user requests and manage data. If user sends request, server begins to process data and writes the state in a table. Why is that so? Does server stop processing data for that user and start to process data for another user or processing for every user is run in a different thread (multithread server)? Event driven programming != Threaded programming, but they can (and should) overlap. Threaded programming is used when multiple

I would like to spawn off threads to perform certain tasks, and use a thread-safe queue to communicate with them. I would also like to be doing IO to a variety of file descriptors while I'm waiting. What's the recommended way to accomplish this? Do I have to created an inter-thread pipe and write to it when the queue goes from no elements to some elements? Isn't there a better way? And if I have to create the inter-thread pipe, why don't more libraries that implement shared queues allow you to create the shared queue and inter-thread pipe as a single entity? Does the fact I want to do this at

Event-driven and asynchronous are often used as synonyms. Are there any differences between the two? Also, what is the difference between epoll and aio ? How do they fit together? Lastly, I've read many times that AIO in Linux is horribly broken. How exactly is it broken? Thanks. c-smile Events is one of the paradigms to achieve asynchronous execution. But not all asynchronous systems use events. That is about semantic meaning of these two - one is super-entity of another. epoll and aio use different metaphors: epoll is a blocking operation ( epoll_wait() ) - you block the thread until some

I'm not very experienced in web programming, and I haven't actually coded anything in Node.js yet, just curious about the event-driven approach . It does seems good. The article explains some bad things that could happen when we use a thread-based approach to handle requests, and should opt for a event-driven approach instead. In thread-based, the cashier/thread is stuck with us until our food/resource is ready. While in event-driven, the cashier send us somewhere out of the request queue so we don't block other requests while waiting for our food. To scale the blocking thread-based, you need