oskit/oskit-20020317/security/queue.h

82 lines
2.4 KiB
C
Executable File

/* FLASK */
/*
* Copyright (c) 1999, 2000 The University of Utah and the Flux Group.
* All rights reserved.
*
* Contributed by the Computer Security Research division,
* INFOSEC Research and Technology Office, NSA.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* A double-ended queue is a singly linked list of
* elements of arbitrary type that may be accessed
* at either end.
*/
#ifndef _QUEUE_H_
#define _QUEUE_H_
typedef void *queue_element_t;
typedef struct queue_node *queue_node_ptr_t;
typedef struct queue_node {
queue_element_t element;
queue_node_ptr_t next;
} queue_node_t;
typedef struct queue_info {
queue_node_ptr_t head;
queue_node_ptr_t tail;
} queue_info_t;
typedef queue_info_t *queue_t;
queue_t queue_create(void);
int queue_insert(queue_t, queue_element_t);
int queue_push(queue_t, queue_element_t);
queue_element_t queue_remove(queue_t);
queue_element_t queue_head(queue_t);
void queue_destroy(queue_t);
/*
Applies the specified function f to each element in the
specified queue.
In addition to passing the element to f, queue_map
passes the specified void* pointer to f on each invocation.
If f returns a non-zero status, then queue_map will cease
iterating through the hash table and will propagate the error
return to its caller.
*/
int queue_map(queue_t, int (*f) (queue_element_t, void *), void *);
/*
Same as queue_map, except that if f returns a non-zero status,
then the element will be removed from the queue and the g
function will be applied to the element.
*/
void queue_map_remove_on_error(queue_t,
int (*f) (queue_element_t, void *),
void (*g) (queue_element_t, void *),
void *);
#endif
/* FLASK */