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/****************************************************************************
* net/iob/iob_initialize.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 <stdbool.h>
#include <semaphore.h>
#include <nuttx/net/iob.h>
#include "iob.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/* This is a pool of pre-allocated I/O buffers */
static struct iob_s g_iob_pool[CONFIG_IOB_NBUFFERS];
#if CONFIG_IOB_NCHAINS > 0
static struct iob_qentry_s g_iob_qpool[CONFIG_IOB_NCHAINS];
#endif
/****************************************************************************
* Public Data
****************************************************************************/
/* A list of all free, unallocated I/O buffers */
FAR struct iob_s *g_iob_freelist;
/* A list of all free, unallocated I/O buffer queue containers */
#if CONFIG_IOB_NCHAINS > 0
FAR struct iob_qentry_s *g_iob_freeqlist;
#endif
/* Counting semaphores that tracks the number of free IOBs/qentries */
sem_t g_iob_sem; /* Counts free I/O buffers */
#if CONFIG_IOB_THROTTLE > 0
sem_t g_throttle_sem; /* Counts available I/O buffers when throttled */
#endif
#if CONFIG_IOB_NCHAINS > 0
sem_t g_qentry_sem; /* Counts free I/O buffer queue containers */
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: iob_initialize
*
* Description:
* Set up the I/O buffers for normal operations.
*
****************************************************************************/
void iob_initialize(void)
{
static bool initialized = false;
int i;
/* Perform one-time initialization */
if (!initialized)
{
/* Add each I/O buffer to the free list */
for (i = 0; i < CONFIG_IOB_NBUFFERS; i++)
{
FAR struct iob_s *iob = &g_iob_pool[i];
/* Add the pre-allocate I/O buffer to the head of the free list */
iob->io_flink = g_iob_freelist;
g_iob_freelist = iob;
}
sem_init(&g_iob_sem, 0, CONFIG_IOB_NBUFFERS);
#if CONFIG_IOB_THROTTLE > 0
sem_init(&g_throttle_sem, 0, CONFIG_IOB_NBUFFERS - CONFIG_IOB_THROTTLE);
#endif
#if CONFIG_IOB_NCHAINS > 0
/* Add each I/O buffer chain queue container to the free list */
for (i = 0; i < CONFIG_IOB_NCHAINS; i++)
{
FAR struct iob_qentry_s *iobq = &g_iob_qpool[i];
/* Add the pre-allocate buffer container to the head of the free list */
iobq->qe_flink = g_iob_freeqlist;
g_iob_freeqlist = iobq;
}
sem_init(&g_qentry_sem, 0, CONFIG_IOB_NCHAINS);
#endif
initialized = true;
}
}
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