net.sourceforge.jobman

Class Scheduler

java.lang.Object

net.sourceforge.jobman.Scheduler

class Scheduler
extends java.lang.Object

This class is the book keeper of exec jobs. It is responsible to keep job queue, to schedule which jobs to run next.

Field Summary

Fields

Modifier and Type	Field and Description
private static java.util.Map<java.lang.String,java.lang.Integer>	forksPerJob The number of running Tasks for each terminal job name.
private static java.util.TreeMap<java.lang.Integer,java.util.LinkedList<Exec>>	jobQueue A map recording the job queue.
private static java.util.LinkedList<Exec>	orphans

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Scheduler() All data and methods are static.

Method Summary

Modifier and Type	Method and Description
(package private) static void	addOrphan(Exec t)
(package private) static java.lang.String	debugDump()
(package private) static int	fork() Starting running a new job in a separate process.
(package private) static int	getRunnings() Get the total number of running jobs.
(package private) static void	leaveQueue(Exec e)
(package private) static void	register(Exec inv) Register a job.
private static boolean	tryInvoke(Exec t) Try to invoke a exec job.
(package private) static void	unregister(Exec i) Report a exec task has just finished.
private static void	updateOrphans()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

jobQueue

private static final java.util.TreeMap<java.lang.Integer,java.util.LinkedList<Exec>> jobQueue

A map recording the job queue. A key is an Integer as rank. A value is LinkedList of Task.

forksPerJob

private static final java.util.Map<java.lang.String,java.lang.Integer> forksPerJob

The number of running Tasks for each terminal job name.

orphans

private static final java.util.LinkedList<Exec> orphans

Constructor Detail

Scheduler

private Scheduler()

All data and methods are static. No object instantiation is allowed.

Method Detail

debugDump

static java.lang.String debugDump()

register

static void register(Exec inv)

Register a job. This means to place the job into queue to be executed. false if the job queue is full, or the limit for this particular job is reached.

leaveQueue

static void leaveQueue(Exec e)

unregister

static void unregister(Exec i)

Report a exec task has just finished.

getRunnings

static int getRunnings()

Get the total number of running jobs.

tryInvoke

private static boolean tryInvoke(Exec t)

Try to invoke a exec job.

Returns:

true if invoke succeeded. Return false if the exec cannot be invoked due to max forks per job name is reached.

fork

static int fork()

Starting running a new job in a separate process.

Returns:

The number of processes forked.

addOrphan

static void addOrphan(Exec t)

updateOrphans

private static void updateOrphans()