org.apache.commons.transaction.locking
Interface MultiLevelLock

All Known Implementing Classes:

GenericLock

public interface MultiLevelLock

A multi level lock. Depending on the implementation more than one owner may own a certain lock level on the same lock.

Version:

$Revision: 1.1 $

See Also:

LockManager

Method Summary

boolean	acquire(Object ownerId, int targetLockLevel, boolean wait, boolean reentrant, long timeoutMSecs) Tries to acquire a certain lock level on this lock.
int	getLockLevel(Object ownerId) Retuns the highest lock level the specified owner holds on this lock or 0 if it holds no locks at all.
void	release(Object ownerId) Releases any lock levels the specified owner may hold on this lock.

Method Detail

acquire

public boolean acquire(Object ownerId,
                       int targetLockLevel,
                       boolean wait,
                       boolean reentrant,
                       long timeoutMSecs)
                throws InterruptedException

Tries to acquire a certain lock level on this lock.

Parameters:

ownerId - a unique id identifying the entity that wants to acquire a certain lock level on this lock

targetLockLevel - the lock level to acquire

wait - true if this method shall block when the desired lock level can not be acquired

reentrant - true if lock levels of the same entity acquired earlier should not restrict compatibility with the lock level desired now

timeoutMSecs - if blocking is enabled by the wait parameter this specifies the maximum wait time in milliseconds

Returns:

true if the lock actually was acquired

Throws:

InterruptedException - when the thread waiting on this method is interrupted

release

public void release(Object ownerId)

Releases any lock levels the specified owner may hold on this lock.

Parameters:

ownerId - a unique id identifying the entity that wants to release all lock levels

getLockLevel

public int getLockLevel(Object ownerId)

Retuns the highest lock level the specified owner holds on this lock or 0 if it holds no locks at all.

Parameters:

ownerId - a unique id identifying the entity that wants to know its highest lock level

Returns:

the highest lock level