diff options
Diffstat (limited to 'nuttx/libc/queue/sq_remlast.c')
-rw-r--r-- | nuttx/libc/queue/sq_remlast.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/nuttx/libc/queue/sq_remlast.c b/nuttx/libc/queue/sq_remlast.c new file mode 100644 index 000000000..8f045e493 --- /dev/null +++ b/nuttx/libc/queue/sq_remlast.c @@ -0,0 +1,87 @@ +/************************************************************ + * libc/queue/sq_remlast.c + * + * Copyright (C) 2007, 2011 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. + * + ************************************************************/ + +/************************************************************ + * Compilation Switches + ************************************************************/ + +/************************************************************ + * Included Files + ************************************************************/ + +#include <queue.h> + +/************************************************************ + * Public Functions + ************************************************************/ + +/************************************************************ + * Name: sq_remlast + * + * Description: + * Removes the last entry in a singly-linked queue. + * + ************************************************************/ + +FAR sq_entry_t *sq_remlast(sq_queue_t *queue) +{ + FAR sq_entry_t *ret = queue->tail; + + if (ret) + { + if (queue->head == queue->tail) + { + queue->head = NULL; + queue->tail = NULL; + } + else + { + FAR sq_entry_t *prev; + for(prev = queue->head; + prev && prev->flink != ret; + prev = prev->flink); + + if (prev) + { + prev->flink = NULL; + queue->tail = prev; + } + } + + ret->flink = NULL; + } + + return ret; +} |