incubator-nuttx/net/iob/iob_free_qentry.c

113 lines
4.2 KiB
C

/****************************************************************************
* net/iob/iob_free_qentry.c
*
* Copyright (C) 2014 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 <nuttx/config.h>
#if defined(CONFIG_DEBUG) && defined(CONFIG_IOB_DEBUG)
/* Force debug output (from this file only) */
# undef CONFIG_DEBUG_NET
# define CONFIG_DEBUG_NET 1
#endif
#include <semaphore.h>
#include <assert.h>
#include <nuttx/arch.h>
#include <nuttx/net/iob.h>
#include "iob.h"
#if CONFIG_IOB_NCHAINS > 0
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: iob_free_qentry
*
* Description:
* Free the I/O buffer chain container by returning it to the free list.
* The link to the next I/O buffer in the chain is return.
*
****************************************************************************/
FAR struct iob_qentry_s *iob_free_qentry(FAR struct iob_qentry_s *iobq)
{
FAR struct iob_qentry_s *nextq = iobq->qe_flink;
irqstate_t flags;
/* Free the I/O buffer chain container by adding it to the head of the free
* list. We don't know what context we are called from so we use extreme
* measures to protect the free list: We disable interrupts very briefly.
*/
flags = irqsave();
iobq->qe_flink = g_iob_freeqlist;
g_iob_freeqlist = iobq;
/* Signal that an I/O buffer chain container is available */
sem_post(&g_qentry_sem);
irqrestore(flags);
/* And return the I/O buffer chain container after the one that was freed */
return nextq;
}
#endif /* CONFIG_IOB_NCHAINS > 0 */