incubator-nuttx/libs/libc/queue/dq_addfirst.c

55 lines
1.9 KiB
C

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