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/****************************************************************************
* sched/task_exithook.c
*
* Copyright (C) 2011-2012 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 <unistd.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "os_internal.h"
#include "sig_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: task_hook
*
* Description:
* This function implements some of the internal logic of exit() and
* task_delete(). This function performs some cleanup and other actions
* required when a task exists:
*
* - All open streams are flushed and closed.
* - All functions registered with atexit() and on_exit() are called, in
* the reverse order of their registration.
*
* When called from exit(), the tcb still resides at the head of the ready-
* to-run list. The following logic is safe because we will not be
* returning from the exit() call.
*
* When called from task_delete() we are operating on a different thread;
* on the thread that called task_delete(). In this case, task_delete
* will have already removed the tcb from the ready-to-run list to prevent
* any further action on this task.
*
****************************************************************************/
void task_exithook(FAR _TCB *tcb, int status)
{
/* If an exit function was registered, call it now before we do any un-
* initialized. NOTE: In the case of task_delete(), the exit function
* will *not* be called on the thread execution of the task being deleted!
*/
#ifdef CONFIG_SCHED_ATEXIT
if (tcb->atexitfunc)
{
/* Call the atexit function */
(*tcb->atexitfunc)();
/* Nullify the atexit function. task_exithook may be called more then
* once in most task exit scenarios. Nullifying the atext function
* pointer will assure that the callback is performed only once.
*/
tcb->atexitfunc = NULL;
}
#endif
#ifdef CONFIG_SCHED_ONEXIT
if (tcb->onexitfunc)
{
/* Call the on_exit function */
(*tcb->onexitfunc)(status, tcb->onexitarg);
/* Nullify the on_exit function. task_exithook may be called more then
* once in most task exit scenarios. Nullifying the on_exit function
* pointer will assure that the callback is performed only once.
*/
tcb->onexitfunc = NULL;
}
#endif
/* Wakeup any tasks waiting for this task to exit */
#ifdef CONFIG_SCHED_WAITPID /* Experimental */
while (tcb->exitsem.semcount < 0)
{
/* "If more than one thread is suspended in waitpid() awaiting
* termination of the same process, exactly one thread will return
* the process status at the time of the target process termination."
* Hmmm.. what do we return to the others?
*/
if (tcb->stat_loc)
{
*tcb->stat_loc = status << 8;
tcb->stat_loc = NULL;
}
/* Wake up the thread */
sem_post(&tcb->exitsem);
}
#endif
/* Flush all streams (File descriptors will be closed when
* the TCB is deallocated).
*/
#if CONFIG_NFILE_STREAMS > 0
(void)lib_flushall(tcb->streams);
#endif
/* Free all file-related resources now. This gets called again
* just be be certain when the TCB is delallocated. However, we
* really need to close files as soon as possible while we still
* have a functioning task.
*/
(void)sched_releasefiles(tcb);
/* Deallocate anything left in the TCB's queues */
#ifndef CONFIG_DISABLE_SIGNALS
sig_cleanup(tcb); /* Deallocate Signal lists */
#endif
}
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