incubator-nuttx/sched/task/task_onexit.c

116 lines
3.8 KiB
C

/****************************************************************************
* sched/task/task_onexit.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* 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 "sched/sched.h"
#include "task/task.h"
#ifdef CONFIG_SCHED_ONEXIT
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: on_exit
*
* Description:
* Registers a function to be called at program exit.
* The on_exit() function registers the given function to be called
* at normal process termination, whether via exit or via return from
* the program's main(). The function is passed the status argument
* given to the last call to exit and the arg argument from on_exit().
*
* NOTE 1: This function comes from SunOS 4, but is also present in
* libc4, libc5 and glibc. It no longer occurs in Solaris (SunOS 5).
* Avoid this function, and use the standard atexit() instead.
*
* NOTE 2: CONFIG_SCHED_ONEXIT must be defined to enable this function
*
* Limitations in the current implementation:
*
* 1. Only a single on_exit function can be registered unless
* CONFIG_SCHED_ONEXIT_MAX defines a larger number.
* 2. on_exit functions are not inherited when a new task is
* created.
*
* Input Parameters:
* func - A pointer to the function to be called when the task exits.
* arg - An argument that will be provided to the on_exit() function when
* the task exits.
*
* Returned Value:
* Zero on success. Non-zero on failure.
*
****************************************************************************/
int on_exit(CODE void (*func)(int, FAR void *), FAR void *arg)
{
FAR struct tcb_s *tcb = this_task();
FAR struct task_group_s *group = tcb->group;
int index;
int ret = ENOSPC;
DEBUGASSERT(group);
/* The following must be atomic */
if (func)
{
sched_lock();
/* Search for the first available slot. on_exit() functions are
* registered from lower to higher array indices; they must be called
* in the reverse order of registration when task exists, i.e.,
* from higher to lower indices.
*/
for (index = 0; index < CONFIG_SCHED_EXIT_MAX; index++)
{
if (!group->tg_exit[index].func.on)
{
group->tg_exit[index].func.on = func;
group->tg_exit[index].arg = arg;
ret = OK;
break;
}
}
sched_unlock();
}
return ret;
}
#endif /* CONFIG_SCHED_ONEXIT */