Class Pool

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

public class Pool extends Object
Pool
Author:
Mladen Turk
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    static ByteBuffer
    alloc(long p, int size)
    Allocate a block of memory from a pool
    static ByteBuffer
    calloc(long p, int size)
    Allocate a block of memory from a pool and set all of the memory to 0
    static void
    Run all of the child_cleanups, so that any unnecessary files are closed because we are about to exec a new program
    static void
    cleanupKill(long pool, long data)
    Remove a previously registered cleanup function
    static long
    cleanupRegister(long pool, Object o)
    Register a function to be called when a pool is cleared or destroyed
    static void
    clear(long pool)
    Clear all memory in the pool and run all the cleanups.
    static long
    create(long parent)
    Create a new pool.
    static Object
    dataGet(long pool, String key)
    Return the data associated with the current pool.
    static int
    dataSet(long pool, String key, Object data)
    Set the data associated with the current pool
    static void
    destroy(long pool)
    Destroy the pool.
    static boolean
    isAncestor(long a, long b)
    Determine if pool a is an ancestor of pool b
    static void
    noteSubprocess(long a, long proc, int how)
    Register a process to be killed when a pool dies.
    static long
    parentGet(long pool)
    Get the parent pool of the specified pool.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • Pool

      public Pool()
  • Method Details

    • create

      public static long create(long parent)
      Create a new pool.
      Parameters:
      parent - The parent pool. If this is 0, the new pool is a root pool. If it is non-zero, the new pool will inherit all of its parent pool's attributes, except the apr_pool_t will be a sub-pool.
      Returns:
      The pool we have just created.
    • clear

      public static void clear(long pool)
      Clear all memory in the pool and run all the cleanups. This also destroys all subpools.
      Parameters:
      pool - The pool to clear This does not actually free the memory, it just allows the pool to re-use this memory for the next allocation.
    • destroy

      public static void destroy(long pool)
      Destroy the pool. This takes similar action as apr_pool_clear() and then frees all the memory. This will actually free the memory
      Parameters:
      pool - The pool to destroy
    • parentGet

      public static long parentGet(long pool)
      Get the parent pool of the specified pool.
      Parameters:
      pool - The pool for retrieving the parent pool.
      Returns:
      The parent of the given pool.
    • isAncestor

      public static boolean isAncestor(long a, long b)
      Determine if pool a is an ancestor of pool b
      Parameters:
      a - The pool to search
      b - The pool to search for
      Returns:
      True if a is an ancestor of b, NULL is considered an ancestor of all pools.
    • cleanupRegister

      public static long cleanupRegister(long pool, Object o)
      Register a function to be called when a pool is cleared or destroyed
      Parameters:
      pool - The pool register the cleanup with
      o - The object to call when the pool is cleared or destroyed
      Returns:
      The cleanup handler.
    • cleanupKill

      public static void cleanupKill(long pool, long data)
      Remove a previously registered cleanup function
      Parameters:
      pool - The pool remove the cleanup from
      data - The cleanup handler to remove from cleanup
    • noteSubprocess

      public static void noteSubprocess(long a, long proc, int how)
      Register a process to be killed when a pool dies.
      Parameters:
      a - The pool to use to define the processes lifetime
      proc - The process to register
      how - How to kill the process, one of:
       APR_KILL_NEVER         -- process is never sent any signals
       APR_KILL_ALWAYS        -- process is sent SIGKILL on apr_pool_t cleanup
       APR_KILL_AFTER_TIMEOUT -- SIGTERM, wait 3 seconds, SIGKILL
       APR_JUST_WAIT          -- wait forever for the process to complete
       APR_KILL_ONLY_ONCE     -- send SIGTERM and then wait
       
    • alloc

      public static ByteBuffer alloc(long p, int size)
      Allocate a block of memory from a pool
      Parameters:
      p - The pool to allocate from
      size - The amount of memory to allocate
      Returns:
      The ByteBuffer with allocated memory
    • calloc

      public static ByteBuffer calloc(long p, int size)
      Allocate a block of memory from a pool and set all of the memory to 0
      Parameters:
      p - The pool to allocate from
      size - The amount of memory to allocate
      Returns:
      The ByteBuffer with allocated memory
    • dataSet

      public static int dataSet(long pool, String key, Object data)
      Set the data associated with the current pool
      Parameters:
      data - The user data associated with the pool.
      key - The key to use for association
      pool - The current pool
      Warning : The data to be attached to the pool should have a life span at least as long as the pool it is being attached to. Object attached to the pool will be globally referenced until the pool is cleared or dataSet is called with the null data.
      Returns:
      APR Status code.
    • dataGet

      public static Object dataGet(long pool, String key)
      Return the data associated with the current pool.
      Parameters:
      key - The key for the data to retrieve
      pool - The current pool.
      Returns:
      the data
    • cleanupForExec

      public static void cleanupForExec()
      Run all of the child_cleanups, so that any unnecessary files are closed because we are about to exec a new program