queue

We are just learning about circular queue in class, and I got a few questions. Since we define the tail as the empty space next to the last value, such as shown below: |1| |3|4|5|6| The head will be pointing to the number 3, and the tail will be pointing to the empty space between 1 and 3. I am confused on what happens if that space is filled up, so for example below: |1|2|3|4|5|6| Then the head will still be pointing to 3, but the tail needs to be pointing to the next box after the blank box before, thus it will be pointing to 3, or the header. What should I do about this? When this situation

How do I queue functions in PHP? I need something that works just like Wordpress's add_action system. I want enqueue function which then runs when the time is right. Edit This seems to work perfectly. Anyone got any tips to improve my code? $enqueued_actions = array(); /** * Enqueue an action to run at a later time. * @param string $hook The hook name. * @param obj $func The function object. * @param integer $imp The level of importance from 0-9 */ function add_action($hook, $func, $imp = 0) { global $enqueued_actions; $enqueued_actions[$hook][] = array('func' => $func, 'imp' => $imp); } /** *

I'm working on a Java-based server in which I will have multiple threads (one thread for each connected user + some extra). There will be some database connection involved, so I was thinking that each time the server makes a SELECT query to the database it will start a new thread for this, to prevent blocking from the current thread. I'm planning on using a connection pool for this and I think I know how to do that. (I've looked into C3P0 ) However, there will be a lot of UPDATE statements involved also, but it's not important that these are ran directly, it's ok with a delay here. And since

Does anyone know how to run a number of processes in the background either through a job queue or parallel processing. I have a number of maintenance updates that take time to run and want to do this in the background. toske I would recomment Gearman server, it prooved quite stable, it's totally outside of Symfony2, and you have to have server up and running (don't know what your hosting options are), but it distribues jobs perfectly. In skiniest version, it just keeps all jobs in-memory, but you can configure it to use sqlite database as backup, so for any reason server reboots, or gearman

As an exercise for learning Go I am writing a basic Queue data structure. I started learning about interfaces yesterday I thought it would be cool to try and use them for this exercise. What I am trying to accomplish is to have a Queue that can accept any type that implements this interface: type Queuable interface { Next() *Queuable // This is probably not right } Basically what I want is to be able to add any type that has a Next() method to my Queue . So what I tried was: type Node struct { value interface{} next *Queuable } // Next gets the next object func (n *Node) Next() *Queuable {

How can we treat a Mysql table as a limited FIFO buffer (Queue). Objectives are : The table at a time can have only N number of rows. When a row is inserted, the oldest row shpuld be deleted to maintain the row count as N. Pls suggest approaches. UPDATE: Sorry guys, as many pointed I changed my question from STACK to FIFO queue Past Mysql 5 you could use a trigger to achieve this. http://dev.mysql.com/doc/refman/5.0/en/create-trigger.html then your triggered sql would be along the lines off: DELETE FROM foo WHERE id NOT IN (SELECT id FROM foo ORDER BY id DESC LIMIT 10) You can just get count