/****************************************************************************
* sched/atexit.c
*
* Copyright (C) 2007, 2009, 2011-2013 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 <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "os_internal.h"
#ifdef CONFIG_SCHED_ATEXIT
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: atexit
*
* Description:
* Registers a function to be called at program exit.
* The atexit() function registers the given function to be called
* at normal process termination, whether via exit or via return from
* the program's main().
*
* NOTE: CONFIG_SCHED_ATEXIT must be defined to enable this function
*
* Limitiations in the current implementation:
*
* 1. Only a single atexit function can be registered unless
* CONFIG_SCHED_ATEXIT_MAX defines a larger number.
* 2. atexit functions are not inherited when a new task is
* created.
* 3. If both SCHED_ONEXIT and SCHED_ATEXIT are selected, then atexit()
* is built on top of the on_exit() implementation. In that case,
* CONFIG_SCHED_ONEXIT_MAX determines the size of the combined
* number of atexit(0) and on_exit calls and SCHED_ATEXIT_MAX is
* not used.
*
* Input Parameters:
* func - A pointer to the function to be called when the task exits.
*
* Return Value:
* Zero on success. Non-zero on failure.
*
****************************************************************************/
int atexit(void (*func)(void))
{
#if defined(CONFIG_SCHED_ONEXIT)
/* atexit is equivalent to on_exit() with no argument (Assuming that the ABI
* can handle a callback function that recieves more parameters than it expects).
*/
return on_exit((onexitfunc_t)func, NULL);
#elif defined(CONFIG_SCHED_ATEXIT_MAX) && CONFIG_SCHED_ATEXIT_MAX > 1
FAR struct tcb_s *tcb = (FAR struct tcb_s*)g_readytorun.head;
FAR struct task_group_s *group = tcb->group;
int index;
int ret = ERROR;
DEBUGASSERT(group);
/* The following must be atomic */
if (func)
{
sched_lock();
/* Search for the first available slot. atexit() functions are registered
* from lower to higher arry indices; they must be called in the reverse
* order of registration when task exists, i.e., from higher to lower
* indices.
*/
available = -1;
for (index = 0; index < CONFIG_SCHED_ATEXIT_MAX; index++)
{
if (!group->tg_atexitfunc[index])
{
group->tg_atexitfunc[index] = func;
ret = OK;
break;
}
}
sched_unlock();
}
return ret;
#else
FAR struct tcb_s *tcb = (FAR struct tcb_s*)g_readytorun.head;
FAR struct task_group_s *group = tcb->group;
int ret = ERROR;
DEBUGASSERT(group);
/* The following must be atomic */
sched_lock();
if (func && !group->tg_atexitfunc)
{
group->tg_atexitfunc = func;
ret = OK;
}
sched_unlock();
return ret;
#endif
}
#endif /* CONFIG_SCHED_ATEXIT */
