X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=qemu-queue.h;h=9288cd8e8260c183e1d328ea04dda9aae82cdf61;hb=11f66978618b542986172a62fcd6acfa36c0d178;hp=22142305a61160232b3fcb20b394c68a7bb4e6bd;hpb=e927dab1fda0eee41fa5fe51ae98293f66a86db1;p=qemu.git diff --git a/qemu-queue.h b/qemu-queue.h index 22142305a..9288cd8e8 100644 --- a/qemu-queue.h +++ b/qemu-queue.h @@ -1,9 +1,9 @@ /* $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */ /* - * Qemu version: Copy from netbsd, removed debug code, removed some of - * the implementations. Left in lists, simple queues, tail queues and - * circular queues. + * QEMU version: Copy from netbsd, removed debug code, removed some of + * the implementations. Left in singly-linked lists, lists, simple + * queues, and tail queues. */ /* @@ -41,8 +41,18 @@ #define QEMU_SYS_QUEUE_H_ /* - * This file defines four types of data structures: - * lists, simple queues, tail queues, and circular queues. + * This file defines four types of data structures: singly-linked lists, + * lists, simple queues, and tail queues. + * + * A singly-linked list is headed by a single forward pointer. The + * elements are singly linked for minimum space and pointer manipulation + * overhead at the expense of O(n) removal for arbitrary elements. New + * elements can be added to the list after an existing element or at the + * head of the list. Elements being removed from the head of the list + * should use the explicit macro for this purpose for optimum + * efficiency. A singly-linked list may only be traversed in the forward + * direction. Singly-linked lists are ideal for applications with large + * datasets and few or no removals or for implementing a LIFO queue. * * A list is headed by a single forward pointer (or an array of forward * pointers for a hash table header). The elements are doubly linked @@ -65,14 +75,6 @@ * after an existing element, at the head of the list, or at the end of * the list. A tail queue may be traversed in either direction. * - * A circle queue is headed by a pair of pointers, one to the head of the - * list and the other to the tail of the list. The elements are doubly - * linked so that an arbitrary element can be removed without a need to - * traverse the list. New elements can be added to the list before or after - * an existing element, at the head of the list, or at the end of the list. - * A circle queue may be traversed in either direction, but has a more - * complex end of list detection. - * * For details on the use of these macros, see the queue(3) manual page. */ @@ -160,6 +162,64 @@ struct { \ #define QLIST_NEXT(elm, field) ((elm)->field.le_next) +/* + * Singly-linked List definitions. + */ +#define QSLIST_HEAD(name, type) \ +struct name { \ + struct type *slh_first; /* first element */ \ +} + +#define QSLIST_HEAD_INITIALIZER(head) \ + { NULL } + +#define QSLIST_ENTRY(type) \ +struct { \ + struct type *sle_next; /* next element */ \ +} + +/* + * Singly-linked List functions. + */ +#define QSLIST_INIT(head) do { \ + (head)->slh_first = NULL; \ +} while (/*CONSTCOND*/0) + +#define QSLIST_INSERT_AFTER(slistelm, elm, field) do { \ + (elm)->field.sle_next = (slistelm)->field.sle_next; \ + (slistelm)->field.sle_next = (elm); \ +} while (/*CONSTCOND*/0) + +#define QSLIST_INSERT_HEAD(head, elm, field) do { \ + (elm)->field.sle_next = (head)->slh_first; \ + (head)->slh_first = (elm); \ +} while (/*CONSTCOND*/0) + +#define QSLIST_REMOVE_HEAD(head, field) do { \ + (head)->slh_first = (head)->slh_first->field.sle_next; \ +} while (/*CONSTCOND*/0) + +#define QSLIST_REMOVE_AFTER(slistelm, field) do { \ + (slistelm)->field.sle_next = \ + QSLIST_NEXT(QSLIST_NEXT((slistelm), field), field); \ +} while (/*CONSTCOND*/0) + +#define QSLIST_FOREACH(var, head, field) \ + for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) + +#define QSLIST_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = QSLIST_FIRST((head)); \ + (var) && ((tvar) = QSLIST_NEXT((var), field), 1); \ + (var) = (tvar)) + +/* + * Singly-linked List access methods. + */ +#define QSLIST_EMPTY(head) ((head)->slh_first == NULL) +#define QSLIST_FIRST(head) ((head)->slh_first) +#define QSLIST_NEXT(elm, field) ((elm)->field.sle_next) + + /* * Simple queue definitions. */ @@ -351,112 +411,4 @@ struct { \ #define QTAILQ_PREV(elm, headname, field) \ (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) - -/* - * Circular queue definitions. - */ -#define QCIRCLEQ_HEAD(name, type) \ -struct name { \ - struct type *cqh_first; /* first element */ \ - struct type *cqh_last; /* last element */ \ -} - -#define QCIRCLEQ_HEAD_INITIALIZER(head) \ - { (void *)&head, (void *)&head } - -#define QCIRCLEQ_ENTRY(type) \ -struct { \ - struct type *cqe_next; /* next element */ \ - struct type *cqe_prev; /* previous element */ \ -} - -/* - * Circular queue functions. - */ -#define QCIRCLEQ_INIT(head) do { \ - (head)->cqh_first = (void *)(head); \ - (head)->cqh_last = (void *)(head); \ -} while (/*CONSTCOND*/0) - -#define QCIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ - (elm)->field.cqe_next = (listelm)->field.cqe_next; \ - (elm)->field.cqe_prev = (listelm); \ - if ((listelm)->field.cqe_next == (void *)(head)) \ - (head)->cqh_last = (elm); \ - else \ - (listelm)->field.cqe_next->field.cqe_prev = (elm); \ - (listelm)->field.cqe_next = (elm); \ -} while (/*CONSTCOND*/0) - -#define QCIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ - (elm)->field.cqe_next = (listelm); \ - (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ - if ((listelm)->field.cqe_prev == (void *)(head)) \ - (head)->cqh_first = (elm); \ - else \ - (listelm)->field.cqe_prev->field.cqe_next = (elm); \ - (listelm)->field.cqe_prev = (elm); \ -} while (/*CONSTCOND*/0) - -#define QCIRCLEQ_INSERT_HEAD(head, elm, field) do { \ - (elm)->field.cqe_next = (head)->cqh_first; \ - (elm)->field.cqe_prev = (void *)(head); \ - if ((head)->cqh_last == (void *)(head)) \ - (head)->cqh_last = (elm); \ - else \ - (head)->cqh_first->field.cqe_prev = (elm); \ - (head)->cqh_first = (elm); \ -} while (/*CONSTCOND*/0) - -#define QCIRCLEQ_INSERT_TAIL(head, elm, field) do { \ - (elm)->field.cqe_next = (void *)(head); \ - (elm)->field.cqe_prev = (head)->cqh_last; \ - if ((head)->cqh_first == (void *)(head)) \ - (head)->cqh_first = (elm); \ - else \ - (head)->cqh_last->field.cqe_next = (elm); \ - (head)->cqh_last = (elm); \ -} while (/*CONSTCOND*/0) - -#define QCIRCLEQ_REMOVE(head, elm, field) do { \ - if ((elm)->field.cqe_next == (void *)(head)) \ - (head)->cqh_last = (elm)->field.cqe_prev; \ - else \ - (elm)->field.cqe_next->field.cqe_prev = \ - (elm)->field.cqe_prev; \ - if ((elm)->field.cqe_prev == (void *)(head)) \ - (head)->cqh_first = (elm)->field.cqe_next; \ - else \ - (elm)->field.cqe_prev->field.cqe_next = \ - (elm)->field.cqe_next; \ -} while (/*CONSTCOND*/0) - -#define QCIRCLEQ_FOREACH(var, head, field) \ - for ((var) = ((head)->cqh_first); \ - (var) != (const void *)(head); \ - (var) = ((var)->field.cqe_next)) - -#define QCIRCLEQ_FOREACH_REVERSE(var, head, field) \ - for ((var) = ((head)->cqh_last); \ - (var) != (const void *)(head); \ - (var) = ((var)->field.cqe_prev)) - -/* - * Circular queue access methods. - */ -#define QCIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) -#define QCIRCLEQ_FIRST(head) ((head)->cqh_first) -#define QCIRCLEQ_LAST(head) ((head)->cqh_last) -#define QCIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) -#define QCIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) - -#define QCIRCLEQ_LOOP_NEXT(head, elm, field) \ - (((elm)->field.cqe_next == (void *)(head)) \ - ? ((head)->cqh_first) \ - : (elm->field.cqe_next)) -#define QCIRCLEQ_LOOP_PREV(head, elm, field) \ - (((elm)->field.cqe_prev == (void *)(head)) \ - ? ((head)->cqh_last) \ - : (elm->field.cqe_prev)) - #endif /* !QEMU_SYS_QUEUE_H_ */