Package org.infinispan.util.concurrent.locks.impl

Class DefaultLockManager

java.lang.Object

org.infinispan.util.concurrent.locks.impl.DefaultLockManager

All Implemented Interfaces:

LockManager

@MBean(objectName="LockManager",
       description="Manager that handles MVCC locks for entries")
public class DefaultLockManager
extends Object
implements LockManager

The default LockManager implementation for transactional and non-transactional caches.

Since:

8.0

Author:

Pedro Ruivo

Constructor Summary

Constructors

Constructor	Description
DefaultLockManager()

Method Summary

Modifier and Type	Method	Description
int	getConcurrencyLevel()
InfinispanLock	getLock(Object key)
int	getNumberOfLocksAvailable()
int	getNumberOfLocksHeld()
Object	getOwner(Object key)	Retrieves the owner of the lock for the key.
boolean	isLocked(Object key)	Tests if the key is locked.
KeyAwareLockPromise	lock(Object key, Object lockOwner, long time, TimeUnit unit)	Attempts to lock the key if the lock isn't already held by the lockOwner.
KeyAwareLockPromise	lockAll(Collection<?> keys, Object lockOwner, long time, TimeUnit unit)	Same as LockManager.lock(Object, Object, long, TimeUnit) but for multiple keys.
boolean	ownsLock(Object key, Object lockOwner)	Tests if the lockOwner owns a lock on the key.
String	printLockInfo()	Prints lock information for all locks.
void	unlock(Object key, Object lockOwner)	Releases the lock for the key if the lockOwner is the lock owner.
void	unlockAll(Collection<?> keys, Object lockOwner)	Same as LockManager.unlock(Object, Object) but for multiple keys.
void	unlockAll(InvocationContext context)	Same as unlockAll(context.getLockedKeys(), context.getKeyLockOwner();.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultLockManager

public DefaultLockManager()

Method Detail

lock

public KeyAwareLockPromise lock(Object key,
                                Object lockOwner,
                                long time,
                                TimeUnit unit)

Description copied from interface: LockManager

Attempts to lock the key if the lock isn't already held by the lockOwner.

This method is non-blocking and return immediately a LockPromise. The LockPromise can (and should) be used by the invoker to check when the lock is really acquired by invoking LockPromise.lock().

Specified by:

lock in interface LockManager

Parameters:

key - key to lock.

lockOwner - the owner of the lock.

time - the maximum time to wait for the lock

unit - the time unit of the time argument

Returns:

the KeyAwareLockPromise associated to this keys.

lockAll

public KeyAwareLockPromise lockAll(Collection<?> keys,
                                   Object lockOwner,
                                   long time,
                                   TimeUnit unit)

Description copied from interface: LockManager

Same as LockManager.lock(Object, Object, long, TimeUnit) but for multiple keys.

It ensures no deadlocks if the method is invoked by different lock owners for the same set (or subset) of keys.

Specified by:

lockAll in interface LockManager

Parameters:

keys - keys to lock.

lockOwner - the owner of the lock.

time - the maximum time to wait for the lock

unit - the time unit of the time argument

Returns:

the KeyAwareLockPromise associated to this keys.

unlock

public void unlock(Object key,
                   Object lockOwner)

Description copied from interface: LockManager

Releases the lock for the key if the lockOwner is the lock owner.

Note this method will unlock a lock where the key is the lockOwner

Specified by:

unlock in interface LockManager

Parameters:

key - key to unlock.

lockOwner - the owner of the lock.

unlockAll

public void unlockAll(Collection<?> keys,
                      Object lockOwner)

Description copied from interface: LockManager

Same as LockManager.unlock(Object, Object) but for multiple keys.

Note this method will not unlock a lock where the key is the lockOwner

Specified by:

unlockAll in interface LockManager

Parameters:

keys - keys to unlock.

lockOwner - the owner of the lock.

unlockAll

public void unlockAll(InvocationContext context)

Description copied from interface: LockManager

Same as unlockAll(context.getLockedKeys(), context.getKeyLockOwner();.

Note this method will not unlock a lock where the key is the lockOwner

Specified by:

unlockAll in interface LockManager

Parameters:

context - the context with the locked keys and the lock owner.

ownsLock

public boolean ownsLock(Object key,
                        Object lockOwner)

Description copied from interface: LockManager

Tests if the lockOwner owns a lock on the key.

Specified by:

ownsLock in interface LockManager

Parameters:

key - key to test.

lockOwner - the owner of the lock.

Returns:

true if the owner does own the lock on the key, false otherwise.

isLocked

public boolean isLocked(Object key)

Description copied from interface: LockManager

Tests if the key is locked.

Specified by:

isLocked in interface LockManager

Parameters:

key - key to test.

Returns:

true if the key is locked, false otherwise.

getOwner

public Object getOwner(Object key)

Description copied from interface: LockManager

Retrieves the owner of the lock for the key.

Specified by:

getOwner in interface LockManager

Returns:

the owner of the lock, or null if not locked.

printLockInfo

public String printLockInfo()

Description copied from interface: LockManager

Prints lock information for all locks.

Specified by:

printLockInfo in interface LockManager

Returns:

the lock information

getNumberOfLocksHeld

@ManagedAttribute(description="The number of exclusive locks that are held.",
                  displayName="Number of locks held")
public int getNumberOfLocksHeld()

Specified by:

getNumberOfLocksHeld in interface LockManager

Returns:

the number of locks held.

getConcurrencyLevel

@ManagedAttribute(description="The concurrency level that the MVCC Lock Manager has been configured with.",
                  displayName="Concurrency level",
                  dataType=TRAIT)
public int getConcurrencyLevel()

getNumberOfLocksAvailable

@ManagedAttribute(description="The number of exclusive locks that are available.",
                  displayName="Number of locks available")
public int getNumberOfLocksAvailable()

getLock

public InfinispanLock getLock(Object key)

Specified by:

getLock in interface LockManager