Pool Cleanup Functions

Overview

Cleanups are performed in the reverse order they were registered. More…

// global functions

void
apr_pool_cleanup_register(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) plain_cleanup,
    apr_status_t(*)(void*) child_cleanup
);

void
apr_pool_pre_cleanup_register(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) plain_cleanup
);

void
apr_pool_cleanup_kill(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) cleanup
);

void
apr_pool_child_cleanup_set(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) plain_cleanup,
    apr_status_t(*)(void*) child_cleanup
);

apr_status_t
apr_pool_cleanup_run(
    apr_pool_t* p,
    void* data,
    apr_status_t(*)(void*) cleanup
);

apr_status_t
apr_pool_cleanup_null(void* data);

void
apr_pool_cleanup_for_exec(void);

Detailed Documentation

Cleanups are performed in the reverse order they were registered. That is: Last In, First Out. A cleanup function can safely allocate memory from the pool that is being cleaned up. It can also safely register additional cleanups which will be run LIFO, directly after the current cleanup terminates. Cleanups have to take caution in calling functions that create subpools. Subpools, created during cleanup will NOT automatically be cleaned up. In other words, cleanups are to clean up after themselves.

Global Functions

void
apr_pool_cleanup_register(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) plain_cleanup,
    apr_status_t(*)(void*) child_cleanup
)

Register a function to be called when a pool is cleared or destroyed

Parameters:

p	The pool to register the cleanup with
data	The data to pass to the cleanup function.
plain_cleanup	The function to call when the pool is cleared or destroyed
child_cleanup	The function to call when a child process is about to exec - this function is called in the child, obviously!

void
apr_pool_pre_cleanup_register(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) plain_cleanup
)

Register a function to be called when a pool is cleared or destroyed.

Unlike apr_pool_cleanup_register which registers a cleanup that is called AFTER all subpools are destroyed, this function registers a function that will be called before any of the subpools are destroyed.

Parameters:

p	The pool to register the cleanup with
data	The data to pass to the cleanup function.
plain_cleanup	The function to call when the pool is cleared or destroyed

void
apr_pool_cleanup_kill(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) cleanup
)

Remove a previously registered cleanup function.

The cleanup most recently registered with p having the same values of data and cleanup will be removed.

For some strange reason only the plain_cleanup is handled by this function

Parameters:

p	The pool to remove the cleanup from
data	The data of the registered cleanup
cleanup	The function to remove from cleanup

void
apr_pool_child_cleanup_set(
    apr_pool_t* p,
    const void* data,
    apr_status_t(*)(void*) plain_cleanup,
    apr_status_t(*)(void*) child_cleanup
)

Replace the child cleanup function of a previously registered cleanup.

The cleanup most recently registered with p having the same values of data and plain_cleanup will have the registered child cleanup function replaced with child_cleanup.

Parameters:

p	The pool of the registered cleanup
data	The data of the registered cleanup
plain_cleanup	The plain cleanup function of the registered cleanup
child_cleanup	The function to register as the child cleanup

apr_status_t
apr_pool_cleanup_run(
    apr_pool_t* p,
    void* data,
    apr_status_t(*)(void*) cleanup
)

Run the specified cleanup function immediately and unregister it.

The cleanup most recently registered with p having the same values of data and cleanup will be removed and cleanup will be called with data as the argument.

Parameters:

p	The pool to remove the cleanup from
data	The data to remove from cleanup
cleanup	The function to remove from cleanup

apr_status_t
apr_pool_cleanup_null(void* data)

An empty cleanup function.

Passed to apr_pool_cleanup_register() when no cleanup is required.

Parameters:

data	The data to cleanup, will not be used by this function.

void
apr_pool_cleanup_for_exec(void)

Run all registered child cleanups, in preparation for an exec() call in a forked child close files, etc., but don’t flush I/O buffers, don’t wait for subprocesses, and don’t free any memory.