Interface LockManager

All Known Implementing Classes:

DefaultLockManager

public interface LockManager

An interface to deal with all aspects of acquiring and releasing locks for cache entries.

Since:

4.0

Author:

Manik Surtani (manik@jboss.org), Mircea.Markus@jboss.com, Pedro Ruivo

Method Summary

Modifier and Type	Method	Description
void	addPostUnlockListener(Object key, Supplier<CompletionStage<Void>> listener)	Registers a listener that will be returned when the current lock owner releases its locks via unlock(Object, Object), unlockAll(Collection, Object), or unlockAll(InvocationContext).
InfinispanLock	getLock(Object key)
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 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.
Collection<Supplier<CompletionStage<Void>>>	unlock(Object key, Object lockOwner)	Releases the lock for the key if the lockOwner is the lock owner.
Collection<Supplier<CompletionStage<Void>>>	unlockAll(Collection<?> keys, Object lockOwner)	Same as unlock(Object, Object) but for multiple keys.
Collection<Supplier<CompletionStage<Void>>>	unlockAll(InvocationContext context)	Same as unlockAll(context.getLockedKeys(), context.getKeyLockOwner();.

Method Details

lock

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.

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().

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

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

Same as 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.

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

Collection<Supplier<CompletionStage<Void>>> unlock(Object key,
 Object lockOwner)

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

Parameters:

key - key to unlock.

lockOwner - the owner of the lock.

Returns:

any post-unlock listener suppliers that were registered for the lock owner.

unlockAll

Collection<Supplier<CompletionStage<Void>>> unlockAll(Collection<?> keys,
 Object lockOwner)

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

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

Parameters:

keys - keys to unlock.

lockOwner - the owner of the lock.

Returns:

any post-unlock listener suppliers that were registered for the unlocked keys.

unlockAll

Collection<Supplier<CompletionStage<Void>>> unlockAll(InvocationContext context)

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

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

Parameters:

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

Returns:

any post-unlock listener suppliers that were registered for the unlocked keys.

addPostUnlockListener

void addPostUnlockListener(Object key,
 Supplier<CompletionStage<Void>> listener)

Registers a listener that will be returned when the current lock owner releases its locks via unlock(Object, Object), unlockAll(Collection, Object), or unlockAll(InvocationContext).

The key must currently be locked. If it is not, an IllegalStateException is thrown. The listener is associated with the current lock owner and will only be returned when that owner's locks are released.

Note: registered listeners are not invoked when the operation that acquired the lock completes with an exception. In that case, the listeners are still drained from the map but are discarded by the interceptor chain.

Parameters:

key - the key that must be currently locked.

listener - a supplier that produces a CompletionStage to be awaited after unlock.

Throws:

IllegalStateException - if the key is not currently locked.

ownsLock

boolean ownsLock(Object key,
 Object lockOwner)

Tests if the lockOwner owns a lock on the key.

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

boolean isLocked(Object key)

Tests if the key is locked.

Parameters:

key - key to test.

Returns:

true if the key is locked, false otherwise.

getOwner

Object getOwner(Object key)

Retrieves the owner of the lock for the key.

Returns:

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

printLockInfo

String printLockInfo()

Prints lock information for all locks.

Returns:

the lock information

getNumberOfLocksHeld

int getNumberOfLocksHeld()

Returns:

the number of locks held.

getLock

InfinispanLock getLock(Object key)