acl/lib_dict/bdb/include/shqueue.h
2014-11-19 00:25:21 +08:00

346 lines
12 KiB
C

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996-2004
* Sleepycat Software. All rights reserved.
*
* $Id: shqueue.h,v 11.15 2004/03/24 20:37:37 bostic Exp $
*/
#ifndef _SYS_SHQUEUE_H_
#define _SYS_SHQUEUE_H_
/*
* This file defines two types of data structures: lists and tail queues
* similarly to the include file <sys/queue.h>.
*
* The difference is that this set of macros can be used for structures that
* reside in shared memory that may be mapped at different addresses in each
* process. In most cases, the macros for shared structures exactly mirror
* the normal macros, although the macro calls require an additional type
* parameter, only used by the HEAD and ENTRY macros of the standard macros.
*
* Since we use relative offsets of type ssize_t rather than pointers, 0
* (aka NULL) is a valid offset and cannot be used to indicate the end
* of a list. Therefore, we use -1 to indicate end of list.
*
* The macros ending in "P" return pointers without checking for end or
* beginning of lists, the others check for end of list and evaluate to
* either a pointer or NULL.
*
* For details on the use of these macros, see the queue(3) manual page.
*/
#if defined(__cplusplus)
extern "C" {
#endif
/*
* Shared memory list definitions.
*/
#define SH_LIST_HEAD(name) \
struct name { \
ssize_t slh_first; /* first element */ \
}
#define SH_LIST_HEAD_INITIALIZER(head) \
{ -1 }
#define SH_LIST_ENTRY \
struct { \
ssize_t sle_next; /* relative offset to next element */ \
ssize_t sle_prev; /* relative offset of prev element */ \
}
/*
* Shared memory list functions.
*/
#define SH_LIST_EMPTY(head) \
((head)->slh_first == -1)
#define SH_LIST_FIRSTP(head, type) \
((struct type *)(((u_int8_t *)(head)) + (head)->slh_first))
#define SH_LIST_FIRST(head, type) \
(SH_LIST_EMPTY(head) ? NULL : \
((struct type *)(((u_int8_t *)(head)) + (head)->slh_first)))
#define SH_LIST_NEXTP(elm, field, type) \
((struct type *)(((u_int8_t *)(elm)) + (elm)->field.sle_next))
#define SH_LIST_NEXT(elm, field, type) \
((elm)->field.sle_next == -1 ? NULL : \
((struct type *)(((u_int8_t *)(elm)) + (elm)->field.sle_next)))
/*
*__SH_LIST_PREV_OFF is private API. It calculates the address of
* the elm->field.sle_next member of a SH_LIST structure. All offsets
* between elements are relative to that point in SH_LIST structures.
*/
#define __SH_LIST_PREV_OFF(elm, field) \
((ssize_t *)(((u_int8_t *)(elm)) + (elm)->field.sle_prev))
#define SH_LIST_PREV(elm, field, type) \
(struct type *)((ssize_t)elm - (*__SH_LIST_PREV_OFF(elm, field)))
#define SH_LIST_FOREACH(var, head, field, type) \
for ((var) = SH_LIST_FIRST((head), type); \
(var); \
(var) = SH_LIST_NEXT((var), field, type))
#define SH_PTR_TO_OFF(src, dest) \
((ssize_t)(((u_int8_t *)(dest)) - ((u_int8_t *)(src))))
/*
* Given correct A.next: B.prev = SH_LIST_NEXT_TO_PREV(A)
* in a list [A, B]
* The prev value is always the offset from an element to its preceding
* element's next location, not the beginning of the structure. To get
* to the beginning of an element structure in memory given an element
* do the following:
* A = B - (B.prev + (&B.next - B))
* Take the element's next pointer and calculate what the corresponding
* Prev pointer should be -- basically it is the negation plus the offset
* of the next field in the structure.
*/
#define SH_LIST_NEXT_TO_PREV(elm, field) \
(((elm)->field.sle_next == -1 ? 0 : -(elm)->field.sle_next) + \
SH_PTR_TO_OFF(elm, &(elm)->field.sle_next))
#define SH_LIST_INIT(head) (head)->slh_first = -1
#define SH_LIST_INSERT_BEFORE(head, listelm, elm, field, type) do { \
if (listelm == SH_LIST_FIRST(head, type)) { \
SH_LIST_INSERT_HEAD(head, elm, field, type); \
} else { \
(elm)->field.sle_next = SH_PTR_TO_OFF(elm, listelm); \
(elm)->field.sle_prev = SH_LIST_NEXT_TO_PREV( \
SH_LIST_PREV((listelm), field, type), field) + \
(elm)->field.sle_next; \
(SH_LIST_PREV(listelm, field, type))->field.sle_next = \
(SH_PTR_TO_OFF((SH_LIST_PREV(listelm, field, \
type)), elm)); \
(listelm)->field.sle_prev = SH_LIST_NEXT_TO_PREV(elm, field); \
} \
} while (0)
#define SH_LIST_INSERT_AFTER(listelm, elm, field, type) do { \
if ((listelm)->field.sle_next != -1) { \
(elm)->field.sle_next = SH_PTR_TO_OFF(elm, \
SH_LIST_NEXTP(listelm, field, type)); \
SH_LIST_NEXTP(listelm, field, type)->field.sle_prev = \
SH_LIST_NEXT_TO_PREV(elm, field); \
} else \
(elm)->field.sle_next = -1; \
(listelm)->field.sle_next = SH_PTR_TO_OFF(listelm, elm); \
(elm)->field.sle_prev = SH_LIST_NEXT_TO_PREV(listelm, field); \
} while (0)
#define SH_LIST_INSERT_HEAD(head, elm, field, type) do { \
if ((head)->slh_first != -1) { \
(elm)->field.sle_next = \
(head)->slh_first - SH_PTR_TO_OFF(head, elm); \
SH_LIST_FIRSTP(head, type)->field.sle_prev = \
SH_LIST_NEXT_TO_PREV(elm, field); \
} else \
(elm)->field.sle_next = -1; \
(head)->slh_first = SH_PTR_TO_OFF(head, elm); \
(elm)->field.sle_prev = SH_PTR_TO_OFF(elm, &(head)->slh_first); \
} while (0)
#define SH_LIST_REMOVE(elm, field, type) do { \
if ((elm)->field.sle_next != -1) { \
SH_LIST_NEXTP(elm, field, type)->field.sle_prev = \
(elm)->field.sle_prev - (elm)->field.sle_next; \
*__SH_LIST_PREV_OFF(elm, field) += (elm)->field.sle_next;\
} else \
*__SH_LIST_PREV_OFF(elm, field) = -1; \
} while (0)
#define SH_LIST_REMOVE_HEAD(head, field, type) do { \
if (!SH_LIST_EMPTY(head)) { \
SH_LIST_REMOVE(SH_LIST_FIRSTP(head, type), field, type);\
} \
} while (0)
/*
* Shared memory tail queue definitions.
*/
#define SH_TAILQ_HEAD(name) \
struct name { \
ssize_t stqh_first; /* relative offset of first element */ \
ssize_t stqh_last; /* relative offset of last's next */ \
}
#define SH_TAILQ_HEAD_INITIALIZER(head) \
{ -1, 0 }
#define SH_TAILQ_ENTRY \
struct { \
ssize_t stqe_next; /* relative offset of next element */ \
ssize_t stqe_prev; /* relative offset of prev's next */ \
}
/*
* Shared memory tail queue functions.
*/
#define SH_TAILQ_EMPTY(head) \
((head)->stqh_first == -1)
#define SH_TAILQ_FIRSTP(head, type) \
((struct type *)((u_int8_t *)(head) + (head)->stqh_first))
#define SH_TAILQ_FIRST(head, type) \
(SH_TAILQ_EMPTY(head) ? NULL : SH_TAILQ_FIRSTP(head, type))
#define SH_TAILQ_NEXTP(elm, field, type) \
((struct type *)((u_int8_t *)(elm) + (elm)->field.stqe_next))
#define SH_TAILQ_NEXT(elm, field, type) \
((elm)->field.stqe_next == -1 ? NULL : \
((struct type *)((u_int8_t *)(elm) + (elm)->field.stqe_next)))
/*
* __SH_TAILQ_PREV_OFF is private API. It calculates the address of
* the elm->field.stqe_next member of a SH_TAILQ structure. All
* offsets between elements are relative to that point in SH_TAILQ
* structures.
*/
#define __SH_TAILQ_PREV_OFF(elm, field) \
((ssize_t *)(((u_int8_t *)(elm)) + (elm)->field.stqe_prev))
#define SH_TAILQ_PREVP(elm, field, type) \
(struct type *)((ssize_t)elm - (*__SH_TAILQ_PREV_OFF(elm, field)))
#define SH_TAILQ_PREV(head, elm, field, type) \
(((elm) == SH_TAILQ_FIRST(head, type)) ? NULL : \
(struct type *)((ssize_t)elm - (*__SH_TAILQ_PREV_OFF(elm, field))))
/*
* __SH_TAILQ_LAST_OFF is private API. It calculates the address of
* the stqe_next member of a SH_TAILQ structure in the last element
* of this list. All offsets between elements are relative to that
* point in SH_TAILQ structures.
*/
#define __SH_TAILQ_LAST_OFF(head) \
((ssize_t *)(((u_int8_t *)(head)) + (head)->stqh_last))
#define SH_TAILQ_LAST(head, field, type) \
(SH_TAILQ_EMPTY(head) ? NULL : \
(struct type *)((ssize_t)(head) + \
((ssize_t)((head)->stqh_last) - \
((ssize_t)SH_PTR_TO_OFF(SH_TAILQ_FIRST(head, type), \
&(SH_TAILQ_FIRST(head, type)->field.stqe_next))))))
/*
* Given correct A.next: B.prev = SH_TAILQ_NEXT_TO_PREV(A)
* in a list [A, B]
* The prev value is always the offset from an element to its preceding
* element's next location, not the beginning of the structure. To get
* to the beginning of an element structure in memory given an element
* do the following:
* A = B - (B.prev + (&B.next - B))
*/
#define SH_TAILQ_NEXT_TO_PREV(elm, field) \
(((elm)->field.stqe_next == -1 ? 0 : \
(-(elm)->field.stqe_next) + \
SH_PTR_TO_OFF(elm, &(elm)->field.stqe_next)))
#define SH_TAILQ_FOREACH(var, head, field, type) \
for ((var) = SH_TAILQ_FIRST((head), type); \
(var); \
(var) = SH_TAILQ_NEXT((var), field, type))
#define SH_TAILQ_FOREACH_REVERSE(var, head, field, type) \
for ((var) = SH_TAILQ_LAST((head), field, type); \
(var); \
(var) = SH_TAILQ_PREV((head), (var), field, type))
#define SH_TAILQ_INIT(head) { \
(head)->stqh_first = -1; \
(head)->stqh_last = SH_PTR_TO_OFF(head, &(head)->stqh_first); \
}
#define SH_TAILQ_INSERT_HEAD(head, elm, field, type) do { \
if ((head)->stqh_first != -1) { \
(elm)->field.stqe_next = \
(head)->stqh_first - SH_PTR_TO_OFF(head, elm); \
SH_TAILQ_FIRSTP(head, type)->field.stqe_prev = \
SH_TAILQ_NEXT_TO_PREV(elm, field); \
} else { \
(head)->stqh_last = \
SH_PTR_TO_OFF(head, &(elm)->field.stqe_next); \
(elm)->field.stqe_next = -1; \
} \
(head)->stqh_first = SH_PTR_TO_OFF(head, elm); \
(elm)->field.stqe_prev = \
SH_PTR_TO_OFF(elm, &(head)->stqh_first); \
} while (0)
#define SH_TAILQ_INSERT_TAIL(head, elm, field) do { \
(elm)->field.stqe_next = -1; \
(elm)->field.stqe_prev = \
-SH_PTR_TO_OFF(head, elm) + (head)->stqh_last; \
if ((head)->stqh_last == \
SH_PTR_TO_OFF((head), &(head)->stqh_first)) \
(head)->stqh_first = SH_PTR_TO_OFF(head, elm); \
else \
*__SH_TAILQ_LAST_OFF(head) = -(head)->stqh_last + \
SH_PTR_TO_OFF((elm), &(elm)->field.stqe_next) + \
SH_PTR_TO_OFF(head, elm); \
(head)->stqh_last = \
SH_PTR_TO_OFF(head, &((elm)->field.stqe_next)); \
} while (0)
#define SH_TAILQ_INSERT_BEFORE(head, listelm, elm, field, type) do { \
if (listelm == SH_TAILQ_FIRST(head, type)) { \
SH_TAILQ_INSERT_HEAD(head, elm, field, type); \
} else { \
(elm)->field.stqe_next = SH_PTR_TO_OFF(elm, listelm); \
(elm)->field.stqe_prev = SH_TAILQ_NEXT_TO_PREV( \
SH_TAILQ_PREVP((listelm), field, type), field) + \
(elm)->field.stqe_next; \
(SH_TAILQ_PREVP(listelm, field, type))->field.stqe_next =\
(SH_PTR_TO_OFF((SH_TAILQ_PREVP(listelm, field, type)), \
elm)); \
(listelm)->field.stqe_prev = \
SH_TAILQ_NEXT_TO_PREV(elm, field); \
} \
} while (0)
#define SH_TAILQ_INSERT_AFTER(head, listelm, elm, field, type) do { \
if ((listelm)->field.stqe_next != -1) { \
(elm)->field.stqe_next = (listelm)->field.stqe_next - \
SH_PTR_TO_OFF(listelm, elm); \
SH_TAILQ_NEXTP(listelm, field, type)->field.stqe_prev = \
SH_TAILQ_NEXT_TO_PREV(elm, field); \
} else { \
(elm)->field.stqe_next = -1; \
(head)->stqh_last = \
SH_PTR_TO_OFF(head, &elm->field.stqe_next); \
} \
(listelm)->field.stqe_next = SH_PTR_TO_OFF(listelm, elm); \
(elm)->field.stqe_prev = SH_TAILQ_NEXT_TO_PREV(listelm, field); \
} while (0)
#define SH_TAILQ_REMOVE(head, elm, field, type) do { \
if ((elm)->field.stqe_next != -1) { \
SH_TAILQ_NEXTP(elm, field, type)->field.stqe_prev = \
(elm)->field.stqe_prev + \
SH_PTR_TO_OFF(SH_TAILQ_NEXTP(elm, \
field, type), elm); \
*__SH_TAILQ_PREV_OFF(elm, field) += elm->field.stqe_next;\
} else { \
(head)->stqh_last = (elm)->field.stqe_prev + \
SH_PTR_TO_OFF(head, elm); \
*__SH_TAILQ_PREV_OFF(elm, field) = -1; \
} \
} while (0)
#if defined(__cplusplus)
}
#endif
#endif /* !_SYS_SHQUEUE_H_ */