b76f19577d
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3441 42af7a65-404d-4744-a932-0658087f49c3
88 lines
3.0 KiB
C
88 lines
3.0 KiB
C
/************************************************************
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* lib/queue/sq_remlast.c
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*
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* Copyright (C) 2007, 2011 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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************************************************************/
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/************************************************************
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* Compilation Switches
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************************************************************/
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/************************************************************
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* Included Files
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************************************************************/
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#include <queue.h>
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/************************************************************
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* Public Functions
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************************************************************/
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/************************************************************
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* Name: sq_remlast
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*
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* Description:
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* Removes the last entry in a singly-linked queue.
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*
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************************************************************/
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FAR sq_entry_t *sq_remlast(sq_queue_t *queue)
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{
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FAR sq_entry_t *ret = queue->tail;
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if (ret)
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{
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if (queue->head == queue->tail)
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{
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queue->head = NULL;
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queue->tail = NULL;
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}
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else
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{
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FAR sq_entry_t *prev;
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for(prev = queue->head;
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prev && prev->flink != ret;
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prev = prev->flink);
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if (prev)
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{
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prev->flink = NULL;
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queue->tail = prev;
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}
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}
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ret->flink = NULL;
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}
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return ret;
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}
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