selinux/checkpolicy/queue.h
2008-08-19 15:30:36 -04:00

63 lines
1.5 KiB
C

/* Author : Stephen Smalley, <sds@epoch.ncsc.mil> */
/* FLASK */
/*
* 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 */