org.openrdf.sail.rdbms.util
Class WritePrefReadWriteLockManager

java.lang.Object
  org.openrdf.sail.rdbms.util.WritePrefReadWriteLockManager

All Implemented Interfaces:

ReadWriteLockManager

public class WritePrefReadWriteLockManager
extends Object
implements ReadWriteLockManager

A read/write lock manager with writer preference. As soon as a write lock is requested, this lock manager will block any read lock requests until the writer's request has been satisfied.

Author:

Arjohn Kampman

Constructor Summary

WritePrefReadWriteLockManager()
Creates a MultiReadSingleWriteLockManager.

WritePrefReadWriteLockManager(boolean trackLocks)
Creates a new MultiReadSingleWriteLockManager, optionally with lock tracking enabled.

Method Summary

Lock	getReadLock() Gets a read lock.
Lock	getWriteLock() Gets an exclusive write lock.
Lock	tryWriteLock() Gets an exclusive write, lock if available.

Methods inherited from class java.lang.Object

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

Constructor Detail

WritePrefReadWriteLockManager

public WritePrefReadWriteLockManager()

Creates a MultiReadSingleWriteLockManager.

WritePrefReadWriteLockManager

public WritePrefReadWriteLockManager(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

getReadLock

public Lock getReadLock()
                 throws InterruptedException

Gets a read lock. This method blocks when a write lock is in use or has been requested until the write lock is released.

Specified by:

getReadLock in interface ReadWriteLockManager

Throws:

InterruptedException

tryWriteLock

public Lock tryWriteLock()

Gets an exclusive write, lock if available. This method will return null if the write lock is in use or has already been requested. This method will return null if any read locks are active.

getWriteLock

public Lock getWriteLock()
                  throws InterruptedException

Gets an exclusive write lock. This method blocks when the write lock is in use or has already been requested until the write lock is released. This method also block when read locks are active until all of them are released.

Specified by:

getWriteLock in interface ReadWriteLockManager

Throws:

InterruptedException