/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

#ifndef APR_LOCKS_H
#define APR_LOCKS_H

#include "apr_general.h"
#include "apr_errno.h"

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

typedef enum {APR_CROSS_PROCESS, APR_INTRAPROCESS, APR_LOCKALL} ap_lockscope_e;

typedef enum {APR_MUTEX, APR_READWRITE} ap_locktype_e;

typedef struct ap_lock_t           ap_lock_t;

/*   Function definitions */
/*

=head1 ap_status_t ap_create_lock(ap_lock_t **lock, ap_locktype_e type, ap_lockscope_e scope, const char *fname, ap_pool_t *cont)

B<Create a new instance of a lock structure.>

    arg 1) The newly created lock structure.
    arg 2) The type of lock to create, one of:
              APR_MUTEX
              APR_READWRITE
    arg 3) The scope of the lock to create, one of:
              APR_CROSS_PROCESS -- lock processes from the protected area.
              APR_INTRAPROCESS  -- lock threads from the protected area.
              APR_LOCKALL       -- lock processes and threads from the
                                   protected area.
    arg 4) 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.
    arg 5) The pool to operate on.

B<NOTE>:  APR_CROSS_PROCESS may lock both processes and threads, but it is
          only guaranteed to lock processes.

=cut
 */
ap_status_t ap_create_lock(ap_lock_t **lock, ap_locktype_e type, 
                           ap_lockscope_e scope, const char *fname, 
                           ap_pool_t *cont);

/*

=head1 ap_status_t ap_lock(ap_lock_t *lock)

B<Lock a protected region.>

    arg 1) The lock to set.

=cut
 */
ap_status_t ap_lock(ap_lock_t *lock);

/*

=head1 ap_status_t ap_unlock(ap_lock_t *lock)

B<Unlock a protected region.>
 
    arg 1) The lock to reset.

=cut
 */
ap_status_t ap_unlock(ap_lock_t *lock);

/*

=head1 ap_status_t ap_destroy_lock(ap_lock_t *lock)

B<Free the memory associated with a lock.>
 
    arg 1) The lock to free.

B<NOTE>:  If the lock is currently active when it is destroyed, it 
          will be unlocked first.

=cut
 */
ap_status_t ap_destroy_lock(ap_lock_t *lock);

/*

=head1 ap_status_t ap_child_init_lock(ap_lock_t **lock, const char *fname, ap_pool_t *cont)

B<Re-open a lock in a child process.>

    arg 1) The newly re-opened lock structure.
    arg 2) 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.  This filename should be the same
           one that was passed to ap_create_lock
    arg 3) The pool to operate on.

B<NOTE>:  This function doesn't always do something, it depends on the
           locking mechanism chosen for the platform, but it is a good
           idea to call it regardless, because it makes the code more
           portable. 

=cut
 */
ap_status_t ap_child_init_lock(ap_lock_t **lock, const char *fname, 
                               ap_pool_t *cont);

/*

=head1 ap_status_t ap_get_lockdata(ap_lock_t *lock, char *key, void *data)

B<Return the pool associated with the current lock.>

    arg 1) The currently open lock.
    arg 2) The key to use when retreiving data associated with this lock
    arg 3) The user data associated with the lock.

=cut
 */
ap_status_t ap_get_lockdata(ap_lock_t *lock, char *key, void *data);

/*

=head1 ap_status_t ap_set_lockdata(ap_lock_t *lock, void *data, char *key, ap_status_t (*cleanup) (void *))

B<Return the pool associated with the current lock.>

    arg 1) The currently open lock.
    arg 2) The user data to associate with the lock.
    arg 3) The key to use when associating data with this lock
    arg 4) The cleanup to use when the lock is destroyed.

=cut
 */
ap_status_t ap_set_lockdata(ap_lock_t *lock, void *data, char *key,
                            ap_status_t (*cleanup) (void *));

#ifdef __cplusplus
}
#endif

#endif  /* ! APR_LOCKS_H */