Package de.aristaflow.adept2.base.sessionmanagement

Class SessionLock.DownwardSubtreeLockCount

java.lang.Object

de.aristaflow.adept2.base.sessionmanagement.SessionLock.AbstractLockCount

de.aristaflow.adept2.base.sessionmanagement.SessionLock.ChildSessionIDLockCount

de.aristaflow.adept2.base.sessionmanagement.SessionLock.DownwardSubtreeLockCount

All Implemented Interfaces:

LockCountManager<SessionToken>

Enclosing class:

SessionLock

public static class SessionLock.DownwardSubtreeLockCount
extends SessionLock.ChildSessionIDLockCount

A LockCountManager considering session tokens and their subsessions (but not vice versa!) as equal. This resembles SessionLock.UpwardSubtreeLockCount but differs in that additional locking sessions move a subtree downwards. This prevents sibling sessions from locking concurrently but only allows for consecutive sibling locking. Locking by parent sessions (ones lying on the way from a root to the top-level session) is allowed.
The subtree will be locked until the last (child) session has unlocked.

The root of a subtree will always be the locking session token with the highest child level. When locking a subtree will move downward if locked by a descendant session and it will move upward in case a current root unlocks.

Constructor Summary

Constructors

Constructor	Description
DownwardSubtreeLockCount()	Creates a new LockCountManager for locking subtrees starting with a specific root which will move downward in case descendant sessions lock.

Method Summary

Modifier and Type	Method	Description
int	decreaseAndGetLockCount(SessionToken session)	Decreases the number of times the designated object holds the lock.
boolean	hasLock(SessionToken session)	Returns whether the designated object has a lock at least once.
int	increaseAndGetLockCount(SessionToken session)	Increases the number of times the designated object holds the lock.

Methods inherited from class de.aristaflow.adept2.base.sessionmanagement.SessionLock.AbstractLockCount

getLockOwner, hasLocks

Methods inherited from class java.lang.Object

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

Constructor Details

DownwardSubtreeLockCount

public DownwardSubtreeLockCount()

Creates a new LockCountManager for locking subtrees starting with a specific root which will move downward in case descendant sessions lock.

Method Details

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>

Overrides:

hasLock in class SessionLock.AbstractLockCount

Parameters:

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

Returns:

Whether the designated object has a lock at least once.

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>

Overrides:

increaseAndGetLockCount in class SessionLock.AbstractLockCount

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>

Overrides:

decreaseAndGetLockCount in class SessionLock.AbstractLockCount

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.