Annotation of prex-old/dev/lib/queue.c, Revision 1.1
1.1 ! nbrk 1: /*-
! 2: * Copyright (c) 2005, Kohsuke Ohtani
! 3: * All rights reserved.
! 4: *
! 5: * Redistribution and use in source and binary forms, with or without
! 6: * modification, are permitted provided that the following conditions
! 7: * are met:
! 8: * 1. Redistributions of source code must retain the above copyright
! 9: * notice, this list of conditions and the following disclaimer.
! 10: * 2. Redistributions in binary form must reproduce the above copyright
! 11: * notice, this list of conditions and the following disclaimer in the
! 12: * documentation and/or other materials provided with the distribution.
! 13: * 3. Neither the name of the author nor the names of any co-contributors
! 14: * may be used to endorse or promote products derived from this software
! 15: * without specific prior written permission.
! 16: *
! 17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
! 18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 20: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
! 21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 27: * SUCH DAMAGE.
! 28: */
! 29:
! 30: /*
! 31: * queue.c - generic queue management library
! 32: */
! 33: #include <queue.h>
! 34:
! 35: /*
! 36: * Insert element at tail of queue
! 37: */
! 38: void
! 39: enqueue(queue_t head, queue_t item)
! 40: {
! 41: item->next = head;
! 42: item->prev = head->prev;
! 43: item->prev->next = item;
! 44: head->prev = item;
! 45: }
! 46:
! 47: /*
! 48: * Remove and return element of head of queue
! 49: */
! 50: queue_t
! 51: dequeue(queue_t head)
! 52: {
! 53: queue_t item;
! 54:
! 55: if (head->next == head)
! 56: return ((queue_t)0);
! 57: item = head->next;
! 58: item->next->prev = head;
! 59: head->next = item->next;
! 60: return item;
! 61: }
! 62:
! 63: /*
! 64: * Insert element after specified element
! 65: */
! 66: void
! 67: queue_insert(queue_t prev, queue_t item)
! 68: {
! 69: item->prev = prev;
! 70: item->next = prev->next;
! 71: prev->next->prev = item;
! 72: prev->next = item;
! 73: }
! 74:
! 75: /*
! 76: * Remove specified element from queue
! 77: */
! 78: void
! 79: queue_remove(queue_t item)
! 80: {
! 81: item->prev->next = item->next;
! 82: item->next->prev = item->prev;
! 83: }
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