[CURATOR-459] Support for asynchronous locks in Curator Async

[jira-importer]

It would be great to have a support for asynchronous locks. Here's an interface suggestion

/**
 * A non-reentrant Lock with the ability to react when the lock is acquired async, so that the thread which
 * acquires the lock is not blocked.
 */
public interface CompletableLock {
/**

• Acquire the lock non-blocking. The resulting {@link CompletableFuture} can then be used to block
• until the lock is actually acquired. The {@link CompletableFuture#cancel(boolean)} can be used
• to abort the acquisition of the lock. As soon as the lock is actually acquired, this method has no
• effect. The Lock itself is then released with {@link Lease#unlock()}.
• Several calls results in several independent locking requests. So it is equivalent to
• call this method multiple times or get a new lock and then call the method once.
• @return an instance of {@link CompletableFuture} which represents the actual lock. */ CompletableFuture<Lease> lock();

default void withLock(Runnable body) { lock().thenAccept(lock -> { try { body.run(); } finally { lock.unlock(); } }); }

/**

• Same as {@link #lock()} but if the lock can't be acquired within the given amount of time,
• the {@link CompletableFuture} throws a {@link java.util.concurrent.ExecutionException} with a nested
• {@link java.util.concurrent.TimeoutException} when it is accessed the next time.
• @param time the maximum waiting time for acquiring the lock.
• @param unit the {@link TimeUnit} for the given time.
• @return an instance of {@link CompletableFuture} which represents the actual lock. */ CompletableFuture<Lease> lock(int time, TimeUnit unit);

/**

• Gets the lock only if possible. If lock is currently acquired, this returns immediately with an undefined option. */ Optional<Lease> tryLock();

/**

• Gets the lock only if possible. If lock is currently acquired, this returns an undefined option after the
• given timeout. */ Lease tryLock(int time, TimeUnit unit);

/**

• For unlocking a successfully acquired lock. */ interface Lease {

/**

• Releases the lock. */ void unlock(); } }

 

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Originally reported by [email protected], imported from: Support for asynchronous locks in Curator Async

• status: Open
• priority: Minor
• resolution: Unresolved
• imported: 2025-01-21

[jira-importer]

randgalt:

Curator has an async lock with LeaderSelector. What's the advantage of adding this?