org.eclipse.rdf4j.common.concurrent.locks

Class LockManager

java.lang.Object

org.eclipse.rdf4j.common.concurrent.locks.LockManager

public class LockManager
extends Object

Manages a set of active locks. If any active lock is garbage collected it is automatically removed from the set and logged.

Author:

James Leigh

Constructor Summary

Constructors

Constructor and Description
LockManager() Create a new set of locks.
LockManager(boolean trackLocks) Creates a new set of locks, optionally with lock tracking enabled.
LockManager(boolean trackLocks, int collectionFrequency) Creates a new set of locks, optionally with lock tracking enabled.

Method Summary

Modifier and Type	Method and Description
Lock	createLock(String alias) Creates a new active lock.
boolean	isActiveLock() If any locks in this collection that are still active.
void	waitForActiveLocks() Blocks current thread until the number of active locks has reached zero.

Methods inherited from class java.lang.Object

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

Constructor Detail

LockManager

public LockManager()

Create a new set of locks.

LockManager

public LockManager(boolean trackLocks)

Creates a new set of locks, optionally with lock tracking enabled.

Parameters:

trackLocks - Controls whether to keep a stack trace of active locks. Enabling lock tracking will add some overhead, but can be very useful for debugging.

LockManager

public LockManager(boolean trackLocks,
                   int collectionFrequency)

Creates a new set of locks, optionally with lock tracking enabled.

Parameters:

trackLocks - Controls whether to keep a stack trace of active locks. Enabling lock tracking will add some overhead, but can be very useful for debugging.

collectionFrequency - Number of milliseconds to block the first thread, waiting for active locks to finish, before running the memory garbage collection, to free abandoned active locks.

Method Detail

isActiveLock

public boolean isActiveLock()

If any locks in this collection that are still active.

Returns:

true of one or more locks that have not be released.

waitForActiveLocks

public void waitForActiveLocks()
                        throws InterruptedException

Blocks current thread until the number of active locks has reached zero.

Throws:

InterruptedException - if any thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.

createLock

public Lock createLock(String alias)

Creates a new active lock. This increases the number of active locks until its Lock.release() method is called, which decreases the number of active locks by the same amount.

Parameters:

alias - a short string used to log abandon locks

Returns:

an active lock