diff options
Diffstat (limited to 'qemu-queue.h')
| -rw-r--r-- | qemu-queue.h | 74 |
1 files changed, 71 insertions, 3 deletions
diff --git a/qemu-queue.h b/qemu-queue.h index 2214230..a8ecfaa 100644 --- a/qemu-queue.h +++ b/qemu-queue.h @@ -2,8 +2,8 @@ /* * Qemu version: Copy from netbsd, removed debug code, removed some of - * the implementations. Left in lists, simple queues, tail queues and - * circular queues. + * the implementations. Left in singly-linked lists, lists, simple + * queues, tail queues and circular queues. */ /* @@ -41,9 +41,19 @@ #define QEMU_SYS_QUEUE_H_ /* - * This file defines four types of data structures: + * This file defines five types of data structures: singly-linked lists, * lists, simple queues, tail queues, and circular 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 * so that an arbitrary element can be removed without a need to @@ -161,6 +171,64 @@ struct { \ /* + * 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. */ #define QSIMPLEQ_HEAD(name, type) \ |