de.aristaflow.adept2.base.sessionmanagement

Class SessionLock.SessionTreePathLockCount

java.lang.Object

de.aristaflow.adept2.base.sessionmanagement.SessionLock.SessionTreePathLockCount

All Implemented Interfaces:

LockCountManager<SessionToken>

Enclosing class:

SessionLock

public static class SessionLock.SessionTreePathLockCount
extends java.lang.Object
implements LockCountManager<SessionToken>

A LockCountManager counting session tokens considering session tokens and their subsessions (but not vice versa!) as equal but prevents locking by siblings. This means, a child session is allowed to lock if a session of a parent level has the lock but no sibling has a lock. Parent sessions may acquire or release a lock while a child keeps the lock. However, ancestors that have not locked yet, may not lock, even if one of their descendants has the lock.
This locks a specific session token path in the session token tree and therefore disallows siblings to have the lock concurrently.

Author:

Ulrich Kreher

Constructor Summary

Constructors

Constructor and Description
SessionTreePathLockCount() Creates a new LockCountManager for session tokens, which considers child sessions as equal to parent sessions but not vice versa.

Method Summary

Modifier and Type	Method and Description
int	decreaseAndGetLockCount(SessionToken session) Decreases the number of times the designated object holds the lock.
java.lang.String	getLockOwner() Returns a string representation of one object that currently has a lock.
boolean	hasLock(SessionToken session) Returns whether the designated object has a lock at least once.
boolean	hasLocks() Returns whether this lock count manager knows at least one object that has a lock.
int	increaseAndGetLockCount(SessionToken session) Increases the number of times the designated object holds the lock.

Methods inherited from class java.lang.Object

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

Constructor Detail

SessionTreePathLockCount

public SessionTreePathLockCount()

Creates a new LockCountManager for session tokens, which considers child sessions as equal to parent sessions but not vice versa.

Method Detail

hasLock

public boolean hasLock(SessionToken session)

Description copied from interface: LockCountManager

Returns whether the designated object has a lock at least once.

Specified by:

hasLock in interface LockCountManager<SessionToken>

Parameters:

session - The object which is checked whether it holds a lock.

Returns:

Whether the designated object has a lock at least once.

hasLocks

public boolean hasLocks()

Description copied from interface: LockCountManager

Returns whether this lock count manager knows at least one object that has a lock.

Specified by:

hasLocks in interface LockCountManager<SessionToken>

Returns:

Whether at least one object has a lock.

getLockOwner

public java.lang.String getLockOwner()

Description copied from interface: LockCountManager

Returns a string representation of one object that currently has a lock. This can be used for user information or tracking purpose. A locking object may not be returned since this would allow to unlock.

Specified by:

getLockOwner in interface LockCountManager<SessionToken>

Returns:

A string representation of one object that currently has a lock.

increaseAndGetLockCount

public int increaseAndGetLockCount(SessionToken session)

Description copied from interface: LockCountManager

Increases the number of times the designated object holds the lock.

Specified by:

increaseAndGetLockCount in interface LockCountManager<SessionToken>

Parameters:

session - The object which has acquired the lock (once again).

Returns:

The number of times the designated object has the lock after the increment.

decreaseAndGetLockCount

public int decreaseAndGetLockCount(SessionToken session)

Description copied from interface: LockCountManager

Decreases the number of times the designated object holds the lock. If the object does not hold the lock, the decrement will be ignored.

Specified by:

decreaseAndGetLockCount in interface LockCountManager<SessionToken>

Parameters:

session - The object which has released the lock (once again).

Returns:

The number of times the designated object has the lock after the decrement.