/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996, 1997 * Sleepycat Software. All rights reserved. * * @(#)shqueue.h 8.12 (Sleepycat) 9/10/97 * %W% (Sun) %G% */ /* * Copyright (c) 1998 by Sun Microsystems, Inc. * All rights reserved. */ #ifndef _SYS_SHQUEUE_H_ #define _SYS_SHQUEUE_H_ /* * This file defines three types of data structures: lists, tail queues, and * circular queues, similarly to the include file . * * 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. * * For details on the use of these macros, see the queue(3) manual page. */ /* * Shared list definitions. */ #define SH_LIST_HEAD(name) \ struct name { \ ssize_t slh_first; /* first element */ \ } #define SH_LIST_ENTRY \ struct { \ ssize_t sle_next; /* relative offset next element */ \ ssize_t sle_prev; /* relative offset of prev element */ \ } /* * Shared list functions. Since we use relative offsets for pointers, * 0 is a valid offset. Therefore, we use -1 to indicate end of list. * The macros ending in "P" return pointers without checking for end * of list, the others check for end of list and evaluate to either a * pointer or NULL. */ #define SH_LIST_FIRSTP(head, type) \ ((struct type *)(((u_int8_t *)(head)) + (head)->slh_first)) #define SH_LIST_FIRST(head, type) \ ((head)->slh_first == -1 ? 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))) #define SH_LIST_PREV(elm, field) \ ((ssize_t *)(((u_int8_t *)(elm)) + (elm)->field.sle_prev)) #define SH_PTR_TO_OFF(src, dest) \ ((ssize_t)(((u_int8_t *)(dest)) - ((u_int8_t *)(src)))) #define SH_LIST_END(head) NULL /* * 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 + SH_PTR_TO_OFF(elm, &(elm)->field.sle_next)) #define SH_LIST_INIT(head) (head)->slh_first = -1 #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(elm, field) += (elm)->field.sle_next; \ } else \ *SH_LIST_PREV(elm, field) = -1; \ } while (0) /* * Shared 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_ENTRY \ struct { \ ssize_t stqe_next; /* relative offset of next element */ \ ssize_t stqe_prev; /* relative offset of prev's next */ \ } /* * Shared tail queue functions. */ #define SH_TAILQ_FIRSTP(head, type) \ ((struct type *)((u_int8_t *)(head) + (head)->stqh_first)) #define SH_TAILQ_FIRST(head, type) \ ((head)->stqh_first == -1 ? 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 : SH_TAILQ_NEXTP(elm, field, type)) #define SH_TAILQ_PREVP(elm, field) \ ((ssize_t *)((u_int8_t *)(elm) + (elm)->field.stqe_prev)) #define SH_TAILQ_LAST(head) \ ((ssize_t *)(((u_int8_t *)(head)) + (head)->stqh_last)) #define SH_TAILQ_NEXT_TO_PREV(elm, field) \ (-(elm)->field.stqe_next + SH_PTR_TO_OFF(elm, &(elm)->field.stqe_next)) #define SH_TAILQ_END(head) NULL #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 { \ (elm)->field.stqe_next = -1; \ (head)->stqh_last = \ SH_PTR_TO_OFF(head, &(elm)->field.stqe_next); \ } \ (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(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_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_PREVP(elm, field) += elm->field.stqe_next; \ } else { \ (head)->stqh_last = (elm)->field.stqe_prev + \ SH_PTR_TO_OFF(head, elm); \ *SH_TAILQ_PREVP(elm, field) = -1; \ } \ } while (0) /* * Shared circular queue definitions. */ #define SH_CIRCLEQ_HEAD(name) \ struct name { \ ssize_t scqh_first; /* first element */ \ ssize_t scqh_last; /* last element */ \ } #define SH_CIRCLEQ_ENTRY \ struct { \ ssize_t scqe_next; /* next element */ \ ssize_t scqe_prev; /* previous element */ \ } /* * Shared circular queue functions. */ #define SH_CIRCLEQ_FIRSTP(head, type) \ ((struct type *)(((u_int8_t *)(head)) + (head)->scqh_first)) #define SH_CIRCLEQ_FIRST(head, type) \ ((head)->scqh_first == -1 ? \ (void *)head : SH_CIRCLEQ_FIRSTP(head, type)) #define SH_CIRCLEQ_LASTP(head, type) \ ((struct type *)(((u_int8_t *)(head)) + (head)->scqh_last)) #define SH_CIRCLEQ_LAST(head, type) \ ((head)->scqh_last == -1 ? (void *)head : SH_CIRCLEQ_LASTP(head, type)) #define SH_CIRCLEQ_NEXTP(elm, field, type) \ ((struct type *)(((u_int8_t *)(elm)) + (elm)->field.scqe_next)) #define SH_CIRCLEQ_NEXT(head, elm, field, type) \ ((elm)->field.scqe_next == SH_PTR_TO_OFF(elm, head) ? \ (void *)head : SH_CIRCLEQ_NEXTP(elm, field, type)) #define SH_CIRCLEQ_PREVP(elm, field, type) \ ((struct type *)(((u_int8_t *)(elm)) + (elm)->field.scqe_prev)) #define SH_CIRCLEQ_PREV(head, elm, field, type) \ ((elm)->field.scqe_prev == SH_PTR_TO_OFF(elm, head) ? \ (void *)head : SH_CIRCLEQ_PREVP(elm, field, type)) #define SH_CIRCLEQ_END(head) ((void *)(head)) #define SH_CIRCLEQ_INIT(head) { \ (head)->scqh_first = 0; \ (head)->scqh_last = 0; \ } #define SH_CIRCLEQ_INSERT_AFTER(head, listelm, elm, field, type) do { \ (elm)->field.scqe_prev = SH_PTR_TO_OFF(elm, listelm); \ (elm)->field.scqe_next = (listelm)->field.scqe_next + \ (elm)->field.scqe_prev; \ if (SH_CIRCLEQ_NEXTP(listelm, field, type) == (void *)head) \ (head)->scqh_last = SH_PTR_TO_OFF(head, elm); \ else \ SH_CIRCLEQ_NEXTP(listelm, \ field, type)->field.scqe_prev = \ SH_PTR_TO_OFF(SH_CIRCLEQ_NEXTP(listelm, \ field, type), elm); \ (listelm)->field.scqe_next = -(elm)->field.scqe_prev; \ } while (0) #define SH_CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field, type) do { \ (elm)->field.scqe_next = SH_PTR_TO_OFF(elm, listelm); \ (elm)->field.scqe_prev = (elm)->field.scqe_next - \ SH_CIRCLEQ_PREVP(listelm, field, type)->field.scqe_next;\ if (SH_CIRCLEQ_PREVP(listelm, field, type) == (void *)(head)) \ (head)->scqh_first = SH_PTR_TO_OFF(head, elm); \ else \ SH_CIRCLEQ_PREVP(listelm, \ field, type)->field.scqe_next = \ SH_PTR_TO_OFF(SH_CIRCLEQ_PREVP(listelm, \ field, type), elm); \ (listelm)->field.scqe_prev = -(elm)->field.scqe_next; \ } while (0) #define SH_CIRCLEQ_INSERT_HEAD(head, elm, field, type) do { \ (elm)->field.scqe_prev = SH_PTR_TO_OFF(elm, head); \ (elm)->field.scqe_next = (head)->scqh_first + \ (elm)->field.scqe_prev; \ if ((head)->scqh_last == 0) \ (head)->scqh_last = -(elm)->field.scqe_prev; \ else \ SH_CIRCLEQ_FIRSTP(head, type)->field.scqe_prev = \ SH_PTR_TO_OFF(SH_CIRCLEQ_FIRSTP(head, type), elm); \ (head)->scqh_first = -(elm)->field.scqe_prev; \ } while (0) #define SH_CIRCLEQ_INSERT_TAIL(head, elm, field, type) do { \ (elm)->field.scqe_next = SH_PTR_TO_OFF(elm, head); \ (elm)->field.scqe_prev = (head)->scqh_last + \ (elm)->field.scqe_next; \ if ((head)->scqh_first == 0) \ (head)->scqh_first = -(elm)->field.scqe_next; \ else \ SH_CIRCLEQ_LASTP(head, type)->field.scqe_next = \ SH_PTR_TO_OFF(SH_CIRCLEQ_LASTP(head, type), elm); \ (head)->scqh_last = -(elm)->field.scqe_next; \ } while (0) #define SH_CIRCLEQ_REMOVE(head, elm, field, type) do { \ if (SH_CIRCLEQ_NEXTP(elm, field, type) == (void *)(head)) \ (head)->scqh_last += (elm)->field.scqe_prev; \ else \ SH_CIRCLEQ_NEXTP(elm, field, type)->field.scqe_prev += \ (elm)->field.scqe_prev; \ if (SH_CIRCLEQ_PREVP(elm, field, type) == (void *)(head)) \ (head)->scqh_first += (elm)->field.scqe_next; \ else \ SH_CIRCLEQ_PREVP(elm, field, type)->field.scqe_next += \ (elm)->field.scqe_next; \ } while (0) #endif /* !_SYS_SHQUEUE_H_ */