incubator-nuttx/libc/queue/sq_cat.c

80 lines
2.9 KiB
C

/****************************************************************************
* libc/queue/sq_cat.c
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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. Neither the name NuttX 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 COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <assert.h>
#include <queue.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sq_cat
*
* Description:
* Move the content of queue1 to the end of queue2.
*
****************************************************************************/
void sq_cat(FAR sq_queue_t *queue1, FAR sq_queue_t *queue2)
{
DEBUGASSERT(queue1 != NULL && queue2 != NULL);
/* If queue2 is empty, then just move queue1 to queue2 */
if (sq_empty(queue2))
{
sq_move(queue1, queue2);
}
/* Do nothing if queue1 is empty */
else if (!sq_empty(queue1))
{
/* Attach the head of queue1 to the final entry of queue2 */
queue2->tail->flink = queue1->head;
/* The tail of queue1 is the new tail of queue2 */
queue2->tail = queue1->tail;
sq_init(queue1);
}
}