org.cache2k.core.concurrency

Class OptimisticLockStamped

java.lang.Object

org.cache2k.core.concurrency.OptimisticLockStamped

All Implemented Interfaces:

OptimisticLock

public class OptimisticLockStamped
extends Object
implements OptimisticLock

Optimistic lock backed by a Java 8 StampedLock

Author:

Jens Wilke

Constructor Summary

Constructors

Constructor and Description
OptimisticLockStamped()

Method Summary

Modifier and Type	Method and Description
long	readLock() Non-exclusively acquires the lock, blocking if necessary until available.
long	tryOptimisticRead() Returns a stamp that can later be validated, or zero if exclusively locked.
void	unlockRead(long stamp) If the lock state matches the given stamp, releases the non-exclusive lock.
void	unlockWrite(long stamp) If the lock state matches the given stamp, releases the exclusive lock.
boolean	validate(long stamp) Returns true if the lock has not been exclusively acquired since issuance of the given stamp.
long	writeLock() Exclusively acquires the lock, blocking if necessary until available.

Methods inherited from class java.lang.Object

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

Constructor Detail

OptimisticLockStamped

public OptimisticLockStamped()

Method Detail

readLock

public long readLock()

Description copied from interface: OptimisticLock

Non-exclusively acquires the lock, blocking if necessary until available.

Specified by:

readLock in interface OptimisticLock

Returns:

a stamp that can be used to unlock or convert mode

writeLock

public long writeLock()

Description copied from interface: OptimisticLock

Exclusively acquires the lock, blocking if necessary until available.

Specified by:

writeLock in interface OptimisticLock

Returns:

a stamp that can be used to unlock or convert mode

tryOptimisticRead

public long tryOptimisticRead()

Description copied from interface: OptimisticLock

Returns a stamp that can later be validated, or zero if exclusively locked. Also ensures that all stores that happened before OptimisticLock.unlockWrite(long) become visible.

Specified by:

tryOptimisticRead in interface OptimisticLock

Returns:

a stamp, or zero if exclusively locked

validate

public boolean validate(long stamp)

Description copied from interface: OptimisticLock

Returns true if the lock has not been exclusively acquired since issuance of the given stamp. Always returns false if the stamp is zero. Always returns true if the stamp represents a currently held lock. Invoking this method with a value not obtained from OptimisticLock.tryOptimisticRead() or a locking method for this lock has no defined effect or result.

Specified by:

validate in interface OptimisticLock

Parameters:

stamp - a stamp

Returns:

true if the lock has not been exclusively acquired since issuance of the given stamp; else false

unlockRead

public void unlockRead(long stamp)

Description copied from interface: OptimisticLock

If the lock state matches the given stamp, releases the non-exclusive lock.

Specified by:

unlockRead in interface OptimisticLock

Parameters:

stamp - a stamp returned by a read-lock operation

unlockWrite

public void unlockWrite(long stamp)

Description copied from interface: OptimisticLock

If the lock state matches the given stamp, releases the exclusive lock.

Specified by:

unlockWrite in interface OptimisticLock

Parameters:

stamp - a stamp returned by a write-lock operation