New file, incorporated from 4.4BSD.
authorroland <roland>
Tue, 2 Jan 1996 06:18:15 +0000 (06:18 +0000)
committerroland <roland>
Tue, 2 Jan 1996 06:18:15 +0000 (06:18 +0000)
misc/queue.h [new file with mode: 0644]

diff --git a/misc/queue.h b/misc/queue.h
new file mode 100644 (file)
index 0000000..65612ce
--- /dev/null
@@ -0,0 +1,245 @@
+/*
+ * Copyright (c) 1991, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *     This product includes software developed by the University of
+ *     California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     @(#)queue.h     8.3 (Berkeley) 12/13/93
+ */
+
+#ifndef        _QUEUE_H_
+#define        _QUEUE_H_
+
+/*
+ * This file defines three types of data structures: lists, tail queues,
+ * and circular queues.
+ *
+ * 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
+ * traverse the list. New elements can be added to the list after
+ * an existing element or at the head of the list. A list may only be
+ * traversed in the forward direction.
+ *
+ * A tail 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 after
+ * an existing element, at the head of the list, or at the end of the
+ * list. A tail queue may only be traversed in the forward 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.
+ */
+
+/*
+ * List definitions.
+ */
+#define LIST_HEAD(name, type)                                          \
+struct name {                                                          \
+       struct type *lh_first;  /* first element */                     \
+}
+
+#define LIST_ENTRY(type)                                               \
+struct {                                                               \
+       struct type *le_next;   /* next element */                      \
+       struct type **le_prev;  /* address of previous next element */  \
+}
+
+/*
+ * List functions.
+ */
+#define        LIST_INIT(head) {                                               \
+       (head)->lh_first = NULL;                                        \
+}
+
+#define LIST_INSERT_AFTER(listelm, elm, field) {                       \
+       if (((elm)->field.le_next = (listelm)->field.le_next) != NULL)  \
+               (listelm)->field.le_next->field.le_prev =               \
+                   &(elm)->field.le_next;                              \
+       (listelm)->field.le_next = (elm);                               \
+       (elm)->field.le_prev = &(listelm)->field.le_next;               \
+}
+
+#define LIST_INSERT_HEAD(head, elm, field) {                           \
+       if (((elm)->field.le_next = (head)->lh_first) != NULL)          \
+               (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
+       (head)->lh_first = (elm);                                       \
+       (elm)->field.le_prev = &(head)->lh_first;                       \
+}
+
+#define LIST_REMOVE(elm, field) {                                      \
+       if ((elm)->field.le_next != NULL)                               \
+               (elm)->field.le_next->field.le_prev =                   \
+                   (elm)->field.le_prev;                               \
+       *(elm)->field.le_prev = (elm)->field.le_next;                   \
+}
+
+/*
+ * Tail queue definitions.
+ */
+#define TAILQ_HEAD(name, type)                                         \
+struct name {                                                          \
+       struct type *tqh_first; /* first element */                     \
+       struct type **tqh_last; /* addr of last next element */         \
+}
+
+#define TAILQ_ENTRY(type)                                              \
+struct {                                                               \
+       struct type *tqe_next;  /* next element */                      \
+       struct type **tqe_prev; /* address of previous next element */  \
+}
+
+/*
+ * Tail queue functions.
+ */
+#define        TAILQ_INIT(head) {                                              \
+       (head)->tqh_first = NULL;                                       \
+       (head)->tqh_last = &(head)->tqh_first;                          \
+}
+
+#define TAILQ_INSERT_HEAD(head, elm, field) {                          \
+       if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
+               (elm)->field.tqe_next->field.tqe_prev =                 \
+                   &(elm)->field.tqe_next;                             \
+       else                                                            \
+               (head)->tqh_last = &(elm)->field.tqe_next;              \
+       (head)->tqh_first = (elm);                                      \
+       (elm)->field.tqe_prev = &(head)->tqh_first;                     \
+}
+
+#define TAILQ_INSERT_TAIL(head, elm, field) {                          \
+       (elm)->field.tqe_next = NULL;                                   \
+       (elm)->field.tqe_prev = (head)->tqh_last;                       \
+       *(head)->tqh_last = (elm);                                      \
+       (head)->tqh_last = &(elm)->field.tqe_next;                      \
+}
+
+#define TAILQ_INSERT_AFTER(head, listelm, elm, field) {                        \
+       if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
+               (elm)->field.tqe_next->field.tqe_prev =                 \
+                   &(elm)->field.tqe_next;                             \
+       else                                                            \
+               (head)->tqh_last = &(elm)->field.tqe_next;              \
+       (listelm)->field.tqe_next = (elm);                              \
+       (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
+}
+
+#define TAILQ_REMOVE(head, elm, field) {                               \
+       if (((elm)->field.tqe_next) != NULL)                            \
+               (elm)->field.tqe_next->field.tqe_prev =                 \
+                   (elm)->field.tqe_prev;                              \
+       else                                                            \
+               (head)->tqh_last = (elm)->field.tqe_prev;               \
+       *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
+}
+
+/*
+ * Circular queue definitions.
+ */
+#define CIRCLEQ_HEAD(name, type)                                       \
+struct name {                                                          \
+       struct type *cqh_first;         /* first element */             \
+       struct type *cqh_last;          /* last element */              \
+}
+
+#define CIRCLEQ_ENTRY(type)                                            \
+struct {                                                               \
+       struct type *cqe_next;          /* next element */              \
+       struct type *cqe_prev;          /* previous element */          \
+}
+
+/*
+ * Circular queue functions.
+ */
+#define        CIRCLEQ_INIT(head) {                                            \
+       (head)->cqh_first = (void *)(head);                             \
+       (head)->cqh_last = (void *)(head);                              \
+}
+
+#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) {              \
+       (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);                              \
+}
+
+#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) {             \
+       (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);                              \
+}
+
+#define CIRCLEQ_INSERT_HEAD(head, elm, field) {                                \
+       (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);                                      \
+}
+
+#define CIRCLEQ_INSERT_TAIL(head, elm, field) {                                \
+       (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);                                       \
+}
+
+#define        CIRCLEQ_REMOVE(head, elm, field) {                              \
+       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;                              \
+}
+#endif /* !_QUEUE_H_ */