org.apache.commons.transaction.locking
Class AbstractLockManager<K,M>

java.lang.Object
  org.apache.commons.transaction.locking.AbstractLockManager<K,M>

All Implemented Interfaces:

LockManager<K,M>

Direct Known Subclasses:

RWLockManager, SimpleLockManager

public abstract class AbstractLockManager<K,M>
extends Object
implements LockManager<K,M>

Abstract implementation of LockManager. You can use this implementation as a base for your custom implementations.

This implementation is thread-safe.

Nested Class Summary

protected static class

AbstractLockManager.KeyEntry<K,M>

Field Summary

protected Map<Thread,Long>	effectiveGlobalTimeouts
protected Map<Thread,Set<Lock>>	locksForThreads

Constructor Summary

AbstractLockManager()

Method Summary

protected void	checkIsStarted()
protected long	computeRemainingTime(Thread thread)
void	endWork() Ends a block of work that has been started in LockManager.startWork(long, TimeUnit).
protected boolean	hasTimedOut(Thread thread)
boolean	isWorking()
void	lock(M resourceManager, K key, boolean exclusive) Locks a resource denoted by a key and a resource manager.
protected abstract void	release()
protected void	reportTimeout(Thread thread)
void	startWork(long timeout, TimeUnit unit) Starts a block of work for which a certain set of locks is required.
boolean	tryLock(M resourceManager, K key, boolean exclusive) Tries to acquire a lock on a resource denoted by a key and a resource manager.
protected abstract boolean	tryLockInternal(M resourceManager, K key, boolean exclusive, long time, TimeUnit unit)

Methods inherited from class java.lang.Object

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

Field Detail

locksForThreads

protected Map<Thread,Set<Lock>> locksForThreads

effectiveGlobalTimeouts

protected Map<Thread,Long> effectiveGlobalTimeouts

Constructor Detail

AbstractLockManager

public AbstractLockManager()

Method Detail

endWork

public void endWork()

Description copied from interface: LockManager

Ends a block of work that has been started in LockManager.startWork(long, TimeUnit). All locks acquired will be released. All registered locks will be unregistered from this lock manager.

Specified by:

endWork in interface LockManager<K,M>

release

protected abstract void release()

startWork

public void startWork(long timeout,
                      TimeUnit unit)

Description copied from interface: LockManager

Starts a block of work for which a certain set of locks is required.

Specified by:

startWork in interface LockManager<K,M>

Parameters:

timeout - the maximum time for the whole work to take before it times out

unit - the time unit of the timeout argument

checkIsStarted

protected void checkIsStarted()

computeRemainingTime

protected long computeRemainingTime(Thread thread)

isWorking

public boolean isWorking()

lock

public void lock(M resourceManager,
                 K key,
                 boolean exclusive)
          throws LockException

Description copied from interface: LockManager

Locks a resource denoted by a key and a resource manager.

Specified by:

lock in interface LockManager<K,M>

Parameters:

resourceManager - resource manager that tries to acquire a lock

key - the key for the resource to be locked

exclusive - true if this lock shall be acquired in exclusive mode, false if it can be shared by other threads

Throws:

LockException - if the lock could not be acquired, possibly because of a timeout or a deadlock

tryLock

public boolean tryLock(M resourceManager,
                       K key,
                       boolean exclusive)

Description copied from interface: LockManager

Tries to acquire a lock on a resource denoted by a key and a resource manager.

Specified by:

tryLock in interface LockManager<K,M>

Parameters:

resourceManager - resource manager that tries to acquire a lock

key - the key for the resource to be locked

exclusive - true if this lock shall be acquired in exclusive mode, false if it can be shared by other threads

Returns:

true if the lock was acquired, false otherwise

tryLockInternal

protected abstract boolean tryLockInternal(M resourceManager,
                                           K key,
                                           boolean exclusive,
                                           long time,
                                           TimeUnit unit)
                                    throws LockException

Throws:

LockException

reportTimeout

protected void reportTimeout(Thread thread)
                      throws LockException

Throws:

LockException

hasTimedOut

protected boolean hasTimedOut(Thread thread)