Package com.ibm.asyncutil.locks

Class FairAsyncNamedLock<T>

java.lang.Object

com.ibm.asyncutil.locks.FairAsyncNamedLock<T>

All Implemented Interfaces:

AsyncNamedLock<T>

public class FairAsyncNamedLock<T>
extends Object
implements AsyncNamedLock<T>

An implementation of the AsyncNamedLock interface which enforces fair ordering in lock acquisition.

null values are not permitted for use as names.

Constructor Summary

Constructors

Constructor	Description
FairAsyncNamedLock()

Method Summary

Modifier and Type	Method	Description
CompletionStage<AsyncLock.LockToken>	acquireLock(T name)	Acquires the lock associated with the given name.
Optional<AsyncLock.LockToken>	tryLock(T name)	Attempts to immediately acquire the lock associated with the given name, returning a populated Optional if the lock is not currently held.

Methods inherited from interface com.ibm.asyncutil.locks.AsyncNamedLock

create, createFair

Methods inherited from class java.lang.Object

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

Constructor Detail

FairAsyncNamedLock

public FairAsyncNamedLock()

Method Detail

acquireLock

public CompletionStage<AsyncLock.LockToken> acquireLock(T name)

Description copied from interface: AsyncNamedLock

Acquires the lock associated with the given name. The returned stage will complete when the lock is exclusively acquired by this caller. The stage may already be complete if the lock was not held.

The AsyncLock.LockToken held by the returned stage is used to release the lock after it has been acquired and the lock-protected action has completed.

Specified by:

acquireLock in interface AsyncNamedLock<T>

Parameters:

name - to acquire exclusive access for

Returns:

A CompletionStage which will complete with a AsyncLock.LockToken when the lock associated with name has been exclusively acquired

tryLock

public Optional<AsyncLock.LockToken> tryLock(T name)

Description copied from interface: AsyncNamedLock

Attempts to immediately acquire the lock associated with the given name, returning a populated Optional if the lock is not currently held.

The AsyncLock.LockToken held by the returned Optional is used to release the lock after it has been acquired and the lock-protected action has completed.

Specified by:

tryLock in interface AsyncNamedLock<T>

Parameters:

name - to acquire exclusive access for

Returns:

An Optional holding a AsyncLock.LockToken if the lock associated with name is not held; otherwise an empty Optional