/****************************************************************************
* sched/task_restart.c
*
* Copyright (C) 2007, 2009, 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 <sys/types.h>
#include <sched.h>
#include <nuttx/arch.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_restart
*
* Description:
* This function "restarts" a task. The task is first terminated and then
* reinitialized with same ID, priority, original entry point, stack size,
* and parameters it had when it was first started.
*
* Inputs:
* pid - The task ID of the task to delete. An ID of zero signifies the
* calling task.
*
* Return Value:
* OK on sucess; ERROR on failure.
*
* This function can fail if:
* (1) A pid of zero or the pid of the calling task is provided
* (functionality not implemented)
* (2) The pid is not associated with any task known to the system.
*
****************************************************************************/
int task_restart(pid_t pid)
{
FAR _TCB *rtcb;
FAR _TCB *tcb;
int status;
irqstate_t state;
/* Make sure this task does not become ready-to-run while
* we are futzing with its TCB
*/
sched_lock();
/* Check if the task to restart is the calling task */
rtcb = (FAR _TCB*)g_readytorun.head;
if ((pid == 0) || (pid == rtcb->pid))
{
/* Not implemented */
return ERROR;
}
/* We are restarting some other task than ourselves */
else
{
/* Find for the TCB associated with matching pid */
tcb = sched_gettcb(pid);
if (!tcb)
{
/* There is no TCB with this pid */
return ERROR;
}
/* Remove the TCB from whatever list it is in. At this point, the
* TCB should no longer be accessible to the system
*/
state = irqsave();
dq_rem((FAR dq_entry_t*)tcb, (dq_queue_t*)g_tasklisttable[tcb->task_state].list);
tcb->task_state = TSTATE_TASK_INVALID;
irqrestore(state);
/* Deallocate anything left in the TCB's queues */
sig_cleanup(tcb); /* Deallocate Signal lists */
/* Reset the current task priority */
tcb->sched_priority = tcb->init_priority;
/* Reset the base task priority and the number of pending reprioritizations */
#ifdef CONFIG_PRIORITY_INHERITANCE
tcb->base_priority = tcb->init_priority;
# if CONFIG_SEM_NNESTPRIO > 0
tcb->npend_reprio = 0;
# endif
#endif
/* Re-initialize the processor-specific portion of the TCB
* This will reset the entry point and the start-up parameters
*/
up_initial_state(tcb);
/* Add the task to the inactive task list */
dq_addfirst((FAR dq_entry_t*)tcb, (dq_queue_t*)&g_inactivetasks);
tcb->task_state = TSTATE_TASK_INACTIVE;
/* Activate the task */
status = task_activate(tcb);
if (status != OK)
{
dq_rem((FAR dq_entry_t*)tcb, (dq_queue_t*)&g_inactivetasks);
sched_releasetcb(tcb);
return ERROR;
}
}
sched_unlock();
return OK;
}
