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Diffstat (limited to 'nuttx/lib/queue/dq_addbefore.c')
-rw-r--r-- | nuttx/lib/queue/dq_addbefore.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/nuttx/lib/queue/dq_addbefore.c b/nuttx/lib/queue/dq_addbefore.c new file mode 100644 index 000000000..c49dff78b --- /dev/null +++ b/nuttx/lib/queue/dq_addbefore.c @@ -0,0 +1,69 @@ +/**************************************************************************** + * lib/queue/dq_addbefore.c + * + * Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 <queue.h> + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: dq_addbefore + * + * Description: + * dq_addbefore adds 'node' before 'next' in 'queue' + * + ****************************************************************************/ + +void dq_addbefore(FAR dq_entry_t *next, FAR dq_entry_t *node, + dq_queue_t *queue) +{ + if (!queue->head || next == queue->head) + { + dq_addfirst(node, queue); + } + else + { + FAR dq_entry_t *prev = next->blink; + node->flink = next; + node->blink = prev; + prev->flink = node; + next->blink = node; + } +} |