org.eclipse.rdf4j.common.concurrent.locks

Class AbstractReadWriteLockManager

java.lang.Object

org.eclipse.rdf4j.common.concurrent.locks.AbstractReadWriteLockManager

All Implemented Interfaces:

ReadWriteLockManager

Direct Known Subclasses:

ReadPrefReadWriteLockManager, WritePrefReadWriteLockManager

public abstract class AbstractReadWriteLockManager
extends Object
implements ReadWriteLockManager

An abstract base implementation of a read/write lock manager.

Author:

Arjohn Kampman, James Leigh

Constructor Summary

Constructors

Constructor and Description
AbstractReadWriteLockManager() Creates a MultiReadSingleWriteLockManager.
AbstractReadWriteLockManager(boolean trackLocks) Creates a new MultiReadSingleWriteLockManager, optionally with lock tracking enabled.

Method Summary

Modifier and Type	Method and Description
protected Lock	createReadLock() Creates a new Lock for reading and increments counter for active readers.
protected Lock	createWriteLock() Creates a new Lock for writing.
protected boolean	isReaderActive() If one or more readers are active
protected boolean	isWriterActive() If a writer is active
protected void	waitForActiveReaders() Blocks current thread until there are no reader locks active.
protected void	waitForActiveWriter() Blocks current thread until after the writer lock is released (if active).

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.common.concurrent.locks.ReadWriteLockManager

getReadLock, getWriteLock, tryReadLock, tryWriteLock

Constructor Detail

AbstractReadWriteLockManager

public AbstractReadWriteLockManager()

Creates a MultiReadSingleWriteLockManager.

AbstractReadWriteLockManager

public AbstractReadWriteLockManager(boolean trackLocks)

Creates a new MultiReadSingleWriteLockManager, optionally with lock tracking enabled.

Parameters:

trackLocks - Controls whether the lock manager will keep track of active locks. Enabling lock tracking will add some overhead, but can be very useful for debugging.

Method Detail

isWriterActive

protected boolean isWriterActive()

If a writer is active

isReaderActive

protected boolean isReaderActive()

If one or more readers are active

waitForActiveWriter

protected void waitForActiveWriter()
                            throws InterruptedException

Blocks current thread until after the writer lock is released (if active).

Throws:

InterruptedException

waitForActiveReaders

protected void waitForActiveReaders()
                             throws InterruptedException

Blocks current thread until there are no reader locks active.

Throws:

InterruptedException

createReadLock

protected Lock createReadLock()

Creates a new Lock for reading and increments counter for active readers. The lock is tracked if lock tracking is enabled. This method is not thread safe itself, the calling method is expected to handle synchronization issues.

Returns:

a read lock.

createWriteLock

protected Lock createWriteLock()

Creates a new Lock for writing. The lock is tracked if lock tracking is enabled. This method is not thread safe itself for performance reasons, the calling method is expected to handle synchronization issues.

Returns:

a write lock.