scheduling

This question is inspired by this other question . If multiple threads are waiting on a synchronized block, and the lock becomes available, who goes first? Is it by thread priority (and then first-come-first-served)? And do the same rules apply for notify (with multiple wait ing threads)? According to this guy: http://tutorials.jenkov.com/java-concurrency/starvation-and-fairness.html Java issues no guarantees about the sequence. So I guess it is not based on thread priority I'll try to look further for an explanation on how Java actually decides who goes first. Someone else mentioned the

Is there a full featured, job scheduling package available for PHP? I'm looking for the PHP equivalent to Java's Quartz . I'm fine having things triggered externally from cron to drive the system. The functionality I'd be looking for: Ability to register task (class/method) to be called at given intervals. Ability to specify whether a given task can be run multiple times (potentially long running methods should not be run multiple times in certain cases). All registered entries/methods could be run in parallel (jobs are backgrounded so that they do not block other timed tasks). Ability to set

After reading this SO question I got a few doubts. Please help in understanding. Scheduling involves deciding when to run a process and for what quantum of time. Does linux kernel schedule a thread or a process? As process and thread are not differentiated inside kernel how a scheduler treats them? How quantum for each thread is decided? a. If a quantum of time (say 100us) is decided for a process is that getting shared between all the threads of the process? or b. A quantum for each thread is decided by the scheduler? Note: Questions 1 and 2 are related and may look the same but just wanted

For my application i create jobs and schedule them with CronTriggers. Each job has only one trigger and both the job name and the trigger names are the same. No jobs share a trigger. Now when i create a cron trigger like this "0/1 * * * * ?" which instructs the job to execute every second, it works just fine. The problem rises when i first pause the job by calling : scheduler.pauseJob(jobName, jobGroup); and then resuming the job after let's say 50 seconds with : scheduler.resumeJob(jobName, jobGroup); What i see is that for these 50 seconds the job did not execute as requested. But the moment

Situation I have a Runnable. I have a class that schedules this Runnable for execution using a ScheduledExecutorService with scheduleWithFixedDelay . Goal I want to alter this class to schedule the Runnable for fixed delay execution either indefinitely, or until it has been run a certain number of times, depending on some parameter that is passed in to the constructor. If possible, I would like to use the same Runnable, as it is conceptually the same thing that should be "run". Possible approaches Approach #1 Have two Runnables, one that cancels the schedule after a number of executions (which