Constructor Detail

• Global

  public Global()

Method Detail

• create

  public static long create(String fname,
            int mech,
            long pool)
                     throws Error

  Create and initialize a mutex that can be used to synchronize both processes and threads. Note: There is considerable overhead in using this API if only cross-process or cross-thread mutual exclusion is required. See apr_proc_mutex.h and apr_thread_mutex.h for more specialized lock routines.
  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 - If an error occurred

• childInit

  public static long childInit(String fname,
               long pool)
                        throws Error

  Re-open a mutex in a child process.

  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. This function must be called to maintain portability, even if the underlying lock mechanism does not require it.

  Returns:

  Newly opened mutex.

  Throws:

  Error - If an error occurred

• lock

  public static int lock(long mutex)

  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)

  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)

  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)

  Destroy the mutex and free the memory associated with the lock.

  Parameters:

  mutex - the mutex to destroy.

  Returns:

  the operation status