ai.eloquent.raft

Interface Theseus.LongLivedLock

All Superinterfaces:

java.lang.AutoCloseable

Enclosing class:

Theseus

public static interface Theseus.LongLivedLock
extends java.lang.AutoCloseable

This holds a lock that is expected to live longer than the duration of a single method call. Usually this lock is associated with a resource that the holder is responsible for. Because forgetting/failing to release long lived locks can be catastrophic, this class packages up a number of safegaurds to ensure that the lock does eventually get released. Since locks auto-release when their owner disconnects from the cluster, this can safely be a part of Theseus, since as soon as Theseus closes these locks no longer need cleaning up anyways.

Method Summary

Modifier and Type	Method and Description
default void	close()
boolean	isCertainlyHeld() Returns true if the lock represented is still certainly held.
boolean	isPerhapsHeld() Returns true if the lock represented has a chance of being held.
java.lang.String	lockName() Returns the name of the lock that is held.
java.util.concurrent.CompletableFuture<java.lang.Boolean>	release() This releases a lock, and cleans up any resources waiting on it.

Method Detail

lockName

java.lang.String lockName()

Returns the name of the lock that is held.

isCertainlyHeld

boolean isCertainlyHeld()

Returns true if the lock represented is still certainly held. If this is true, isPerhapsHeld() is always true as well, but not visa versa.

isPerhapsHeld

boolean isPerhapsHeld()

Returns true if the lock represented has a chance of being held. This can be true even when isCertainlyHeld() is false, in cases where we are in the process of releasing the lock. Note that unlike isCertainlyHeld(), this may never revert to false in rare cases when we cannot talk to Raft effectively. Therefore, the caller should be wary of waiting on this function.

release

java.util.concurrent.CompletableFuture<java.lang.Boolean> release()

This releases a lock, and cleans up any resources waiting on it. Calling this more than once is a no-op.

close

default void close()
            throws java.lang.Exception

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.lang.Exception