org.apache.lucene.store

## Class Lock

- java.lang.Object
- - org.apache.lucene.store.Lock

- All Implemented Interfaces:
    Closeable, AutoCloseable

      public abstract class Lock
      extends Object
      implements Closeable

  An interprocess mutex lock.

  Typical use might look like:

         try (final Lock lock = directory.obtainLock("my.lock")) {
           // ... code to execute while locked ...
         }

  See Also:
    `Directory.obtainLock(String)`
  NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `Lock()`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `abstract void` | `close()` Releases exclusive access.
    `abstract void` | `ensureValid()` Best effort check that this lock is still valid.

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### Lock

          public Lock()

  - ### Method Detail

    - #### close

          public abstract void close()
                              throws IOException

      Releases exclusive access.

      Note that exceptions thrown from close may require human intervention, as it may mean the lock was no longer valid, or that fs permissions prevent removal of the lock file, or other reasons.

      Specified by:
        `close` in interface `Closeable`
      Specified by:
        `close` in interface `AutoCloseable`
      Throws:
        `LockReleaseFailedException` - optional specific exception) if the lock could not be properly released.
        `IOException`

    - #### ensureValid

          public abstract void ensureValid()
                                    throws IOException

      Best effort check that this lock is still valid. Locks could become invalidated externally for a number of reasons, for example if a user deletes the lock file manually or when a network filesystem is in use.
      Throws:
        `IOException` - if the lock is no longer valid.

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