nuttx/arch/sim/src/up_exit.c

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/************************************************************
* up_exit.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 Gregory Nutt 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 <sys/types.h>
#include <sched.h>
#include <debug.h>
#include <nuttx/arch.h>
#include "os_internal.h"
#include "up_internal.h"
/************************************************************
* Private Definitions
************************************************************/
/************************************************************
* Private Data
************************************************************/
/************************************************************
* Private Funtions
************************************************************/
/************************************************************
* Public Funtions
************************************************************/
/************************************************************
* Name: _exit
*
* Description:
* This function causes the currently executing task to cease
* to exist. This is a special case of task_delete().
*
************************************************************/
void _exit(int status)
{
_TCB* tcb = (_TCB*)g_readytorun.head;
sdbg("TCB=%p exitting\n", tcb);
/* Remove the tcb task from the ready-to-run list. We can
* ignore the return value because we know that a context
* switch is needed.
*/
(void)sched_removereadytorun(tcb);
/* We are not in a bad stack-- the head of the ready to run task list
* does not correspond to the thread that is running. Disabling pre-
* emption on this TCB should be enough to keep things stable.
*/
sched_lock();
/* Move the TCB to the specified blocked task list and delete it */
sched_addblocked(tcb, TSTATE_TASK_INACTIVE);
task_delete(tcb->pid);
/* If there are any pending tasks, then add them to the g_readytorun
* task list now.
*/
if (g_pendingtasks.head)
{
(void)sched_mergepending();
}
/* Now calling sched_unlock() should have no effect */
sched_unlock();
/* Now, perform the context switch to the new ready-to-run task at the
* head of the list.
*/
tcb = (_TCB*)g_readytorun.head;
sdbg("New Active Task TCB=%p\n", tcb);
/* The way that we handle signals in the simulation is kind of
* a kludge. This would be unsafe in a truly multi-threaded, interrupt
* driven environment.
*/
if (tcb->xcp.sigdeliver)
{
sdbg("Delivering signals TCB=%p\n", tcb);
((sig_deliver_t)tcb->xcp.sigdeliver)(tcb);
tcb->xcp.sigdeliver = NULL;
}
/* Then switch contexts */
up_longjmp(tcb->xcp.regs, 1);
}