px4-firmware/nuttx/sched/task_exithook.c

291 lines
9.6 KiB
C

/****************************************************************************
* 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/sched.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
****************************************************************************/
/****************************************************************************
* Name: task_atexit
*
* Description:
* Call any registerd atexit function(s)
*
****************************************************************************/
#if defined(CONFIG_SCHED_ATEXIT) && !defined(CONFIG_SCHED_ONEXIT)
static inline void task_atexit(FAR _TCB *tcb)
{
#if defined(CONFIG_SCHED_ATEXIT_MAX) && CONFIG_SCHED_ATEXIT_MAX > 1
int index;
/* Call each atexit function in reverse order of registration 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.
*/
for (index = CONFIG_SCHED_ATEXIT_MAX-1; index >= 0; index--)
{
if (tcb->atexitfunc[index])
{
/* Call the atexit function */
(*tcb->atexitfunc[index])();
/* 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[index] = NULL;
}
}
#else
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
#else
# define task_atexit(tcb)
#endif
/****************************************************************************
* Name: task_onexit
*
* Description:
* Call any registerd on)exit function(s)
*
****************************************************************************/
#ifdef CONFIG_SCHED_ONEXIT
static inline void task_onexit(FAR _TCB *tcb, int status)
{
#if defined(CONFIG_SCHED_ONEXIT_MAX) && CONFIG_SCHED_ONEXIT_MAX > 1
int index;
/* Call each on_exit function in reverse order of registration. on_exit()
* 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.
*/
for (index = CONFIG_SCHED_ONEXIT_MAX-1; index >= 0; index--)
{
if (tcb->onexitfunc[index])
{
/* Call the on_exit function */
(*tcb->onexitfunc[index])(status, tcb->onexitarg[index]);
/* Nullify the on_exit 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->onexitfunc[index] = NULL;
}
}
#else
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
}
#else
# define task_onexit(tcb,status)
#endif
/****************************************************************************
* Name: task_exitwakeup
*
* Description:
* Wakeup any tasks waiting for this task to exit
*
****************************************************************************/
#ifdef CONFIG_SCHED_WAITPID
static inline void task_exitwakeup(FAR _TCB *tcb, int status)
{
/* Wakeup any tasks waiting for this task to exit */
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);
}
}
#else
# define task_exitwakeup(tcb, status)
#endif
/****************************************************************************
* 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 exit function(s) were registered, call them now before we do any un-
* initialization. NOTE: In the case of task_delete(), the exit function
* will *not* be called on the thread execution of the task being deleted!
*/
task_atexit(tcb);
/* Call any registered on_exit function(s) */
task_onexit(tcb, status);
/* Wakeup any tasks waiting for this task to exit */
task_exitwakeup(tcb, status);
/* 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
}