org.apache.tomcat.jni
Class Pool

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

public class Pool
extends Object

Pool

Version:

$Id: Pool.java 939309 2010-04-29 13:54:26Z kkolinko $

Author:

Mladen Turk

Constructor Summary

Pool()

Method Summary

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	cleanupForExec() 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 Detail

Pool

public Pool()

Method Detail

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.

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