com.ten60.netkernel.util
Class AsynchLock

java.lang.Object
  com.ten60.netkernel.util.AsynchLock

public class AsynchLock
extends java.lang.Object

Atomic lock request and aquire. unlock might return a released previously unaquired lock request if one exists.
not thread safe- external synchronization must be provided.

Constructor Summary

AsynchLock(int aKeyCount, int aContentionCount)
Creates a new instance of AsynchLock

Method Summary

java.util.Iterator	getPendingReferences() returns an iterator over all pending lock request references
boolean	lock(java.lang.Object aKey, java.lang.Object aReference) Attempt to gain an exclusive lock on the given key, takes a reference object to hang onto if the lock fails to be granted that is then returned on an unlock when the lock has been granted
java.lang.Object	unlock(java.lang.Object aKey) releases a lock on the given key, this method must only be called after a lock has been granted.

Methods inherited from class java.lang.Object

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

Constructor Detail

AsynchLock

public AsynchLock(int aKeyCount,
                  int aContentionCount)

Creates a new instance of AsynchLock

Parameters:

aKeyCount - size to make lock map

aContentionCount - expected lock contention count- so as to allocate a list long enough to hold them without needing to expand

Method Detail

lock

public boolean lock(java.lang.Object aKey,
                    java.lang.Object aReference)

Attempt to gain an exclusive lock on the given key, takes a reference object to hang onto if the lock fails to be granted that is then returned on an unlock when the lock has been granted

Parameters:

aKey - the key object that we want to gain an exclusive lock on

aReference - a reference object for the request to lock

Returns:

true if the lock has been granted, false if not

unlock

public java.lang.Object unlock(java.lang.Object aKey)

releases a lock on the given key, this method must only be called after a lock has been granted. The returned lock request reference must be acted on by the client and not ignored.

Parameters:

aKey - the key object that we are releasing the exclusive lock on

Returns:

a lock request reference object to a previously ungranted lock request, null if there is none.

getPendingReferences

public java.util.Iterator getPendingReferences()

returns an iterator over all pending lock request references