org.apache.catalina.tribes.transport.bio.util

Class SingleRemoveSynchronizedAddLock

public class SingleRemoveSynchronizedAddLock extends Object

The class SingleRemoveSynchronizedAddLock implement locking for accessing the queue by a single remove thread and multiple add threads. A thread is only allowed to be either the remove or an add thread. The lock can either be owned by the remove thread or by a single add thread. If the remove thread tries to get the lock, but the queue is empty, it will block (poll) until an add threads adds an entry to the queue and releases the lock. If the remove thread and add threads compete for the lock and an add thread releases the lock, then the remove thread will get the lock first. The remove thread removes all entries in the queue at once and proceeses them without further polling the queue. The lock is not reentrant, in the sense, that all threads must release an owned lock before competing for the lock again!

Version: 1.1

Author: Rainer Jung Peter Rossbach

Constructor Summary
	SingleRemoveSynchronizedAddLock()
	SingleRemoveSynchronizedAddLock(boolean dataAvailable)

Method Summary
void	abortRemove() Abort any polling remover thread
long	getAddWaitTimeout()
long	getRemoveWaitTimeout()
boolean	isAddLocked() Check if an add thread owns the lock.
boolean	isDataAvailable() Check if the locked object has data available i.e. the remover can stop poling and get the lock.
boolean	isRemoveLocked() Check if the remove thread owns the lock.
boolean	isRemovePolling() Check if the remove thread is polling.
void	lockAdd() Acquires the lock by an add thread and sets the add flag.
boolean	lockRemove() Acquires the lock by the remove thread and sets the remove flag.
void	setAddWaitTimeout(long timeout) Set value of addWaitTimeout
void	setRemoveWaitTimeout(long timeout) Set value of removeWaitTimeout
void	unlockAdd(boolean dataAvailable) Releases the lock by an add thread and reset the remove flag.
void	unlockRemove() Releases the lock by the remove thread and reset the add flag.