Lock (Apache Tomcat 9.0.120 API Documentation)
Description: declaration: package: org.apache.tomcat.jni, class: Lock

# Class Lock

java.lang.Object
org.apache.tomcat.jni.Lock

@Deprecated public class Lock extends Object
Deprecated.
The scope of the APR/Native Library will be reduced in Tomcat 9.1.x / Tomcat Native 2.x and has been reduced in Tomcat 10.1.x / Tomcat Native 2.x onwards to only include those components required to provide OpenSSL integration with the NIO and NIO2 connectors.
Lock.

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `APR_LOCK_DEFAULT`
  Deprecated.
  Use the default process lock
  `static final int`
  `APR_LOCK_FCNTL`
  Deprecated.
  fcntl()
  `static final int`
  `APR_LOCK_FLOCK`
  Deprecated.
  flock()
  `static final int`
  `APR_LOCK_POSIXSEM`
  Deprecated.
  POSIX semaphore process-based locking
  `static final int`
  `APR_LOCK_PROC_PTHREAD`
  Deprecated.
  POSIX pthread process-based locking
  `static final int`
  `APR_LOCK_SYSVSEM`
  Deprecated.
  System V Semaphores

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `Lock()`
  Deprecated.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static long`
  `childInit(String fname, long pool)`
  Deprecated.
  Re-open a mutex in a child process.
  `static long`
  `create(String fname, int mech, long pool)`
  Deprecated.
  Create and initialize a mutex that can be used to synchronize processes.
  `static String`
  `defname()`
  Deprecated.
  Display the name of the default mutex: APR_LOCK_DEFAULT
  `static int`
  `destroy(long mutex)`
  Deprecated.
  Destroy the mutex and free the memory associated with the lock.
  `static int`
  `lock(long mutex)`
  Deprecated.
  Acquire the lock for the given mutex.
  `static String`
  `lockfile(long mutex)`
  Deprecated.
  Return the name of the lockfile for the mutex, or NULL if the mutex doesn't use a lock file
  `static String`
  `name(long mutex)`
  Deprecated.
  Display the name of the mutex, as it relates to the actual method used.
  `static int`
  `trylock(long mutex)`
  Deprecated.
  Attempt to acquire the lock for the given mutex.
  `static int`
  `unlock(long mutex)`
  Deprecated.
  Release the lock for the given mutex.

  ### Methods inherited from class Object

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

- ## Field Details

  - ### APR_LOCK_FCNTL

    public static final int APR_LOCK_FCNTL
    Deprecated.
    fcntl()
    See Also:
      - Constant Field Values

  - ### APR_LOCK_FLOCK

    public static final int APR_LOCK_FLOCK
    Deprecated.
    flock()
    See Also:
      - Constant Field Values

  - ### APR_LOCK_SYSVSEM

    public static final int APR_LOCK_SYSVSEM
    Deprecated.
    System V Semaphores
    See Also:
      - Constant Field Values

  - ### APR_LOCK_PROC_PTHREAD

    public static final int APR_LOCK_PROC_PTHREAD
    Deprecated.
    POSIX pthread process-based locking
    See Also:
      - Constant Field Values

  - ### APR_LOCK_POSIXSEM

    public static final int APR_LOCK_POSIXSEM
    Deprecated.
    POSIX semaphore process-based locking
    See Also:
      - Constant Field Values

  - ### APR_LOCK_DEFAULT

    public static final int APR_LOCK_DEFAULT
    Deprecated.
    Use the default process lock
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### Lock

    public Lock()
    Deprecated.

- ## Method Details

  - ### create

    public static long create(String fname, int mech, long pool) throws Error
    Deprecated.
    Create and initialize a mutex that can be used to synchronize processes.
    Warning : Check APR_HAS_foo_SERIALIZE defines to see if the platform supports APR_LOCK_foo. Only APR_LOCK_DEFAULT is portable.
    Parameters:
      `fname` - A file name to use if the lock mechanism requires one. This argument should always be provided. The lock code itself will determine if it should be used.
      `mech` - The mechanism to use for the interprocess lock, if any; one of

                     APR_LOCK_FCNTL
                     APR_LOCK_FLOCK
                     APR_LOCK_SYSVSEM
                     APR_LOCK_POSIXSEM
                     APR_LOCK_PROC_PTHREAD
                     APR_LOCK_DEFAULT     pick the default mechanism for the platform

      `pool` - the pool from which to allocate the mutex.
    Returns:
      Newly created mutex.
    Throws:
      `Error` - An error occurred

  - ### childInit

    public static long childInit(String fname, long pool) throws Error
    Deprecated.
    Re-open a mutex in a child process. This function must be called to maintain portability, even if the underlying lock mechanism does not require it.
    Parameters:
      `fname` - A file name to use if the mutex mechanism requires one. This argument should always be provided. The mutex code itself will determine if it should be used. This filename should be the same one that was passed to apr_proc_mutex_create().
      `pool` - The pool to operate on.
    Returns:
      Newly opened mutex.
    Throws:
      `Error` - An error occurred

  - ### lock

    public static int lock(long mutex)
    Deprecated.
    Acquire the lock for the given mutex. If the mutex is already locked, the current thread will be put to sleep until the lock becomes available.
    Parameters:
      `mutex` - the mutex on which to acquire the lock.
    Returns:
      the operation status

  - ### trylock

    public static int trylock(long mutex)
    Deprecated.
    Attempt to acquire the lock for the given mutex. If the mutex has already been acquired, the call returns immediately with APR_EBUSY. Note: it is important that the APR_STATUS_IS_EBUSY(s) macro be used to determine if the return value was APR_EBUSY, for portability reasons.
    Parameters:
      `mutex` - the mutex on which to attempt the lock acquiring.
    Returns:
      the operation status

  - ### unlock

    public static int unlock(long mutex)
    Deprecated.
    Release the lock for the given mutex.
    Parameters:
      `mutex` - the mutex from which to release the lock.
    Returns:
      the operation status

  - ### destroy

    public static int destroy(long mutex)
    Deprecated.
    Destroy the mutex and free the memory associated with the lock.
    Parameters:
      `mutex` - the mutex to destroy.
    Returns:
      the operation status

  - ### lockfile

    public static String lockfile(long mutex)
    Deprecated.
    Return the name of the lockfile for the mutex, or NULL if the mutex doesn't use a lock file
    Parameters:
      `mutex` - the name of the mutex
    Returns:
      the name of the lock file

  - ### name

    public static String name(long mutex)
    Deprecated.
    Display the name of the mutex, as it relates to the actual method used. This matches the valid options for Apache's AcceptMutex directive
    Parameters:
      `mutex` - the name of the mutex
    Returns:
      the name of the mutex

  - ### defname

    public static String defname()
    Deprecated.
    Display the name of the default mutex: APR_LOCK_DEFAULT
    Returns:
      the default name