com.hazelcast.concurrent.lock

Class LockStoreProxy

java.lang.Object

com.hazelcast.concurrent.lock.LockStoreProxy

All Implemented Interfaces:

LockStore

public final class LockStoreProxy
extends Object
implements LockStore

Proxy to a LockStoreImpl. Since a LockStoreImpl may be destroyed upon service reset (eg. after a split-brain is healed), some of this proxy's methods employ get-or-create to locate the LockStoreImpl or get-or-null when creation of the LockStoreImpl is not required and its absence is interpreted as "no lock exists".

Constructor Summary

Constructors

Constructor and Description
LockStoreProxy(LockStoreContainer container, ObjectNamespace namespace)

Method Summary

Modifier and Type	Method and Description
boolean	canAcquireLock(Data key, String caller, long threadId) Return if the key can be locked by the caller and thread ID.
boolean	extendLeaseTime(Data key, String caller, long threadId, long leaseTime) Extend the lease time for an already locked key.
boolean	forceUnlock(Data key) Unlock the key regardless of the owner.
int	getLockCount(Data key) Return the number of times a key was locked by the same owner (re-entered).
int	getLockedEntryCount() Return the number of locks this store holds.
Set<Data>	getLockedKeys() Return all locked keys for this store.
String	getOwnerInfo(Data dataKey) Return a string representation of the owner of the lock for a specific key.
long	getRemainingLeaseTime(Data key) Return the remaining lease time for a specific key.
boolean	isLocked(Data key) Check if a key is locked by any caller and thread ID.
boolean	isLockedBy(Data key, String caller, long threadId) Check if a key is locked by a specific caller and thread ID.
boolean	localLock(Data key, String caller, long threadId, long referenceId, long leaseTime) Lock a specific key on a local partition only.
boolean	lock(Data key, String caller, long threadId, long referenceId, long leaseTime) Lock a specific key.
boolean	shouldBlockReads(Data key) Return whether the reads for the specific key should be blocked (see LockStore.txnLock(Data, String, long, long, long, boolean)).
boolean	txnLock(Data key, String caller, long threadId, long referenceId, long leaseTime, boolean blockReads) Lock a specific key for use inside a transaction.
boolean	unlock(Data key, String caller, long threadId, long referenceId) Unlock a specific key.

Methods inherited from class java.lang.Object

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

Constructor Detail

LockStoreProxy

public LockStoreProxy(LockStoreContainer container,
                      ObjectNamespace namespace)

Method Detail

lock

public boolean lock(Data key,
                    String caller,
                    long threadId,
                    long referenceId,
                    long leaseTime)

Description copied from interface: LockStore

Lock a specific key.

Specified by:

lock in interface LockStore

Parameters:

key - the key to lock

caller - the identifier for the caller

threadId - the identifier for the thread on the caller

referenceId - the identifier for the invocation of the caller (e.g. operation call ID)

leaseTime - the lease duration in milliseconds

Returns:

if the lock was successfully acquired

localLock

public boolean localLock(Data key,
                         String caller,
                         long threadId,
                         long referenceId,
                         long leaseTime)

Description copied from interface: LockStore

Lock a specific key on a local partition only. Does not observe LOCK_MAX_LEASE_TIME_SECONDS

Specified by:

localLock in interface LockStore

Parameters:

key - the key to lock

caller - the identifier for the caller

threadId - the identifier for the thread on the caller

referenceId - the identifier for the invocation of the caller (e.g. operation call ID)

leaseTime - the lease duration in milliseconds

Returns:

if the lock was successfully acquired

See Also:

GroupProperty.LOCK_MAX_LEASE_TIME_SECONDS

txnLock

public boolean txnLock(Data key,
                       String caller,
                       long threadId,
                       long referenceId,
                       long leaseTime,
                       boolean blockReads)

Description copied from interface: LockStore

Lock a specific key for use inside a transaction.

Specified by:

txnLock in interface LockStore

Parameters:

key - the key to lock

caller - the identifier for the caller

threadId - the identifier for the thread on the caller

referenceId - the identifier for the invocation of the caller (e.g. operation call ID)

leaseTime - the lease duration in milliseconds

blockReads - whether reads for the key should be blocked (e.g. for map and multimap)

Returns:

if the lock was successfully acquired

extendLeaseTime

public boolean extendLeaseTime(Data key,
                               String caller,
                               long threadId,
                               long leaseTime)

Description copied from interface: LockStore

Extend the lease time for an already locked key.

Specified by:

extendLeaseTime in interface LockStore

Parameters:

key - the locked key

caller - the identifier for the caller

threadId - the identifier for the thread on the caller

leaseTime - time in milliseconds for the lease to be extended

Returns:

if the lease was extended

unlock

public boolean unlock(Data key,
                      String caller,
                      long threadId,
                      long referenceId)

Description copied from interface: LockStore

Unlock a specific key.

Specified by:

unlock in interface LockStore

Parameters:

key - the locked key

caller - the identifier for the caller

threadId - the identifier for the thread on the caller

referenceId - the identifier for the invocation of the caller (e.g. operation call ID)

Returns:

if the key was unlocked

isLocked

public boolean isLocked(Data key)

Description copied from interface: LockStore

Check if a key is locked by any caller and thread ID.

Specified by:

isLocked in interface LockStore

Parameters:

key - the key

Returns:

if the key is locked

isLockedBy

public boolean isLockedBy(Data key,
                          String caller,
                          long threadId)

Description copied from interface: LockStore

Check if a key is locked by a specific caller and thread ID.

Specified by:

isLockedBy in interface LockStore

Parameters:

key - the locked key

caller - the identifier for the caller

threadId - the identifier for the thread on the caller

Returns:

if the key is locked

getLockCount

public int getLockCount(Data key)

Description copied from interface: LockStore

Return the number of times a key was locked by the same owner (re-entered).

Specified by:

getLockCount in interface LockStore

Parameters:

key - the key

Returns:

the reentry count

getLockedEntryCount

public int getLockedEntryCount()

Description copied from interface: LockStore

Return the number of locks this store holds.

Specified by:

getLockedEntryCount in interface LockStore

Returns:

the lock count

getRemainingLeaseTime

public long getRemainingLeaseTime(Data key)

Description copied from interface: LockStore

Return the remaining lease time for a specific key.

Specified by:

getRemainingLeaseTime in interface LockStore

Parameters:

key - the key

Returns:

the lease time in milliseconds, -1 if there is no lock, if the key is locked indefinitely

canAcquireLock

public boolean canAcquireLock(Data key,
                              String caller,
                              long threadId)

Description copied from interface: LockStore

Return if the key can be locked by the caller and thread ID.

Specified by:

canAcquireLock in interface LockStore

Parameters:

key - the locked key

caller - the identifier for the caller

threadId - the identifier for the thread on the caller

Returns:

if the key can be locked. Returns false if the key is already locked by a different caller or thread ID

shouldBlockReads

public boolean shouldBlockReads(Data key)

Description copied from interface: LockStore

Return whether the reads for the specific key should be blocked (see LockStore.txnLock(Data, String, long, long, long, boolean)).

Specified by:

shouldBlockReads in interface LockStore

Parameters:

key - the lock key

Returns:

if the reads should be blocked

getLockedKeys

public Set<Data> getLockedKeys()

Description copied from interface: LockStore

Return all locked keys for this store. A lock may be expired when this method returns.

Specified by:

getLockedKeys in interface LockStore

Returns:

all locked keys

forceUnlock

public boolean forceUnlock(Data key)

Description copied from interface: LockStore

Unlock the key regardless of the owner. May return true if the key is already unlocked but has waiters/signals/expired operations.

Specified by:

forceUnlock in interface LockStore

Parameters:

key - the lock key

Returns:

false if there is no lock for the given key and true otherwise

getOwnerInfo

public String getOwnerInfo(Data dataKey)

Description copied from interface: LockStore

Return a string representation of the owner of the lock for a specific key. If the key is not locked returns a default string depicting no owner.

Specified by:

getOwnerInfo in interface LockStore

Parameters:

dataKey - the key

Returns:

a string description/representation of the owner