55 lines
1.9 KiB
C
55 lines
1.9 KiB
C
/****************************************************************************
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* libs/libc/queue/dq_addbefore.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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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: dq_addbefore
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*
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* Description:
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* dq_addbefore adds 'node' before 'next' in 'queue'
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*
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****************************************************************************/
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void dq_addbefore(FAR dq_entry_t *next, FAR dq_entry_t *node,
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dq_queue_t *queue)
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{
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if (!queue->head || next == queue->head)
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{
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dq_addfirst(node, queue);
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}
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else
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{
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FAR dq_entry_t *prev = next->blink;
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node->flink = next;
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node->blink = prev;
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prev->flink = node;
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next->blink = node;
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}
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}
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