org.apache.manifoldcf.crawler.system
Class ResetManager

java.lang.Object
  org.apache.manifoldcf.crawler.system.ResetManager

Direct Known Subclasses:

DocCleanupResetManager, DocDeleteResetManager, JobNotificationThread.NotificationResetManager, SeedingThread.SeedingResetManager, StartDeleteThread.DeleteStartupResetManager, StartupThread.StartupResetManager, WorkerResetManager

public abstract class ResetManager
extends java.lang.Object

The reset manager basically keeps track of threads that work together. If the threads get hosed as a result of problems, then certain resets need to be done. Each instance of this manager therefore tracks all the threads which depend or affect a condition that needs explicit resetting. When a thread recognizes that the database (or whatever resource) is potentially in a state where a reset for the particular condition is required, then the corresponding reset manager object will cause all dependent threads to block, until they are all accounted for. Then, the corrective reset is done, and the threads are released (with a signal corresponding to the fact that a reset occurred returned). This class is meant to be extended in order to implement the exact reset functionality required.

Field Summary

static java.lang.String	_rcsid
protected int	involvedThreadCount This is the count of the threads that care about this resource.
protected boolean	resetRequired Boolean which describes whether an event requiring reset has occurred.
protected int	waitingThreads This is the number of threads that are waiting for the reset.

Constructor Summary

ResetManager()
Constructor.

Method Summary

void	noteEvent() Note a resettable event.
protected abstract void	performResetLogic(IThreadContext tc) Do the reset logic.
void	registerMe() Register a thread with this reset manager.
boolean	waitForReset(IThreadContext tc) Enter "wait" state for current thread.

Methods inherited from class java.lang.Object

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

Field Detail

_rcsid

public static final java.lang.String _rcsid

See Also:

Constant Field Values

resetRequired

protected boolean resetRequired

Boolean which describes whether an event requiring reset has occurred.

involvedThreadCount

protected int involvedThreadCount

This is the count of the threads that care about this resource.

waitingThreads

protected int waitingThreads

This is the number of threads that are waiting for the reset.

Constructor Detail

ResetManager

public ResetManager()

Constructor.

Method Detail

registerMe

public void registerMe()

Register a thread with this reset manager.

noteEvent

public void noteEvent()

Note a resettable event.

waitForReset

public boolean waitForReset(IThreadContext tc)
                     throws ManifoldCFException,
                            java.lang.InterruptedException

Enter "wait" state for current thread. This method is the main logic for the reset manager. A thread calls this method, which may block until all other threads are waiting too. Then, the reset method is called by exactly ONE of the waiting threads, and they all are released.

Returns:

false if no reset took place, or true if one did.

Throws:

ManifoldCFException

java.lang.InterruptedException

performResetLogic

protected abstract void performResetLogic(IThreadContext tc)
                                   throws ManifoldCFException

Do the reset logic.

Throws:

ManifoldCFException