scheduling

Heuristic algorithm for load balancing among threads.

I'm working on a multi-threaded program where I have a number of worker threads performing tasks of unequal length. I want to load-balance the tasks to ensure that they do roughly the same amount of work. For each task Ti I have a number ci which provides a good approximation to the amount of work that is required for that task. ...

Lawler's Algorithm Implementation Assistance

UPDATE2: I think I got it now: <?php /* * @name Lawler's algorithm PHP implementation * @desc This algorithm calculates an optimal schedule of jobs to be * processed on a single machine (in reversed order) while taking * into consideration any precedence constraints. * @author Richard Knop * */ $jobs = array(1 => a...

Run a program or method at specific time in Java

I just want that my program or method should run at specific date and time. i have heard about Timer and TimerTask in java API. But don't know exactly how to use it. ...

How can I schedule tasks in a WinForms app?

QUESTION: How can I schedule tasks in a WinForms app? That is either (a) what is the best approach / .NET classes/methods to use of (b) if there is an open source component that does this well which one would be recommended. BACKGROUND: Winforms app (.NET v3.5, C#, VS2008) I'm assuming I will run the winforms application always, an...

CRON jobs in php deployed in windows platform

How to run a scheduled job scripted in php using windows? I'm using Windows XP sp3. ...

Quartz job fires multiple times

Hi, I have a building block which sets up a Quartz job to send out emails every morning. The job is fired three times every morning instead of once. We have a hosted instance of Blackboard, which I am told runs on three virtual servers. I am guessing this is what is causing the problem, as the building block was previously working fine ...

PHP queue jobs in centOS

I wrote a PHP shell script which include queuing jobs in centOS with 'at' command. The queue jobs may vary in time and contents which means the system need to keep quite a large number of jobs. The application logic will also be a bit difficult to setup with cronjob. Is there a limit in number of queue jobs in centOS or is there any alte...

project plan scheduling...

I am looking for some algorithm/library to get functionality like microsoft project caters for scheduling tasks dates as if we change any task date then its parent, predecessors and successors dates get effected. is there any help i can get... in any way.. Thanks, ...

"Work stealing" vs. "Work shrugging"?

Why is it that I can find lots of information on "work stealing" and nothing on "work shrugging" as a dynamic load-balancing strategy? By "work-shrugging" I mean pushing surplus work away from busy processors onto less loaded neighbours, rather than have idle processors pulling work from busy neighbours ("work-stealing"). I think the ...

Is Work Stealing always the most appropriate user-level thread scheduling algorithm?

I've been investigating different scheduling algorithms for a thread pool I am implementing. Due to the nature of the problem I am solving I can assume that the tasks being run in parallel are independent and do not spawn any new tasks. The tasks can be of varying sizes. I went immediately for the most popular scheduling algorithm "wo...

How to run my script x times a day? (ruby on linux)

I want to run my ruby script x times a day (the number might change) on my linux box. What would be the best way to do so if I do not want it to happen at the same time? I want the time (hour and minute) to be random I was thinking of using at command. The script would be called by at in x hours/minutes or so and then the script would s...

How to parameterize @Scheduled(fixedDelay) with Spring 3.0 expression language?

When using the Spring 3.0 capability to annotate a scheduled task, I would like to set the fixedDelay as parameter from my configuration file, instead of hard-wiring it into my task class, like currently... @Scheduled(fixedDelay=5000) public void readLog() { ... } Unfortunately it seems that with the means of the Spring Expres...

Synchronizing Asynchronous request handlers in Silverlight environment

For our senior design project my group is making a Silverlight application that utilizes graph theory concepts and stores the data in a database on the back end. We have a situation where we add a link between two nodes in the graph and upon doing so we run analysis to re-categorize our clusters of nodes. The problem is that this re-cate...

Does SetThreadPriority cause thread reschedulling?

Consider following situation, assuming single CPU system: thread A is running with a priority THREAD_PRIORITY_NORMAL, signals event E thread B with a priority THREAD_PRIORITY_LOWEST is waiting for an event E (Note: at this point the thread is not scheduled because it is runnable, but A is higher priority and runnable as well) thread A ...

notification scheduling question

Hi Stackers! I'm building an app that needs to send out notifications to users depending on user definable "notifications". So the notifications are not per event. They are arbitrary. A cron job should query the database and send out emails when it finds an event with matching criterion. The is a scheduling app. So naturally, one of th...

nptl SIGCONT and thread scheduling

Hello, I'm trying to port a code that relies on SIGCONT to stop certain threads of an application. With current linux nptl implementation seems one can't rely on that in 2.6.x kernels. I'm trying to devise a method to stop other threads. Currently I can only think on mutexes and condition variables. Any hints is appreciated. ...

Is there a scheduling algorithm that optimizes for "maker's schedules"?

You may be familiar with Paul Graham's essay, "Maker's Schedule, Manager's Schedule". The crux of the essay is that for creative and technical professionals, meetings are anathema to productivity, because they tend to lead to "schedule fragmentation", breaking up free time into chunks that are too small to acquire the focus needed to sol...

Blocking syscalls with no other load in system (linux kernel)

Hello If there is only 1 running application in the system (and default 100 sleeping process), and it do a blocking syscall (I'm interested in blocking recv or blocking read). Will linux kernel delete this application from task_t *current pointer? ...

Finding Last Fired time using a Cron Expression in Java

Is there a way in Java to find the "Last Fired Time" from a Cron Expression. E.g. If now = 25-Apr-2010 10pm, cron expression "0 15 10 ? * *" (quartz) should return me 25-Apr-2010 10:15am Note: 1) I do not care if we use standard cron expressions (like Unix and Quartz) or less popular ones if they can fetch me the correct "Last Fired Ti...

Some examples for common Real Time processes in Linux

What are some of the common SCHED_FIFO and SCHED_RR processes in Linux? Does user input falls under the cantegory of Real Time processes? ...