incubator-nuttx/mm/iob/iob_navail.c

126 lines
3.5 KiB
C

/****************************************************************************
* mm/iob/iob_navail.c
*
* Copyright (C) 2018 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>
#include <stdbool.h>
#include <nuttx/mm/iob.h>
#include "iob.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: iob_navail
*
* Description:
* Return the number of of available IOBs.
*
****************************************************************************/
int iob_navail(bool throttled)
{
int navail = 0;
int ret;
#if CONFIG_IOB_NBUFFERS > 0
/* Get the value of the IOB counting semaphores */
ret = nxsem_getvalue(&g_iob_sem, &navail);
if (ret >= 0)
{
ret = navail;
#if CONFIG_IOB_THROTTLE > 0
/* Subtract the throttle value is so requested */
if (throttled)
{
ret -= CONFIG_IOB_THROTTLE;
}
#endif
if (ret < 0)
{
ret = 0;
}
}
#else
ret = navail;
#endif
return ret;
}
/****************************************************************************
* Name: iob_qentry_navail
*
* Description:
* Return the number of available IOB chains.
*
****************************************************************************/
int iob_qentry_navail(void)
{
int navail = 0;
int ret;
#if CONFIG_IOB_NCHAINS > 0
/* Get the value of the IOB chain qentry counting semaphores */
ret = nxsem_getvalue(&g_qentry_sem, &navail);
if (ret >= 0)
{
ret = navail;
if (ret < 0)
{
ret = 0;
}
}
#else
ret = navail;
#endif
return ret;
}