incubator-nuttx/sched/task/task_restart.c

235 lines
6.8 KiB
C

/****************************************************************************
* sched/task/task_restart.c
*
* Copyright (C) 2007, 2009, 2012-2013, 2016, 2018 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 <errno.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include "sched/sched.h"
#include "group/group.h"
#include "signal/signal.h"
#include "task/task.h"
/****************************************************************************
* 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.
*
* Input Parameters:
* pid - The task ID of the task to delete. An ID of zero signifies the
* calling task.
*
* Returned Value:
* Zero (OK) on success; -1 (ERROR) on failure with the errno variable set
* appropriately.
*
* 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 struct tcb_s *rtcb;
FAR struct task_tcb_s *tcb;
FAR dq_queue_t *tasklist;
irqstate_t flags;
int errcode;
#ifdef CONFIG_SMP
int cpu;
#endif
int ret;
/* Check if the task to restart is the calling task */
rtcb = this_task();
if ((pid == 0) || (pid == rtcb->pid))
{
/* Not implemented */
errcode = ENOSYS;
goto errout;
}
/* We are restarting some other task than ourselves. Make sure that the
* task does not change its state while we are executing. In the single
* CPU state this could be done by disabling pre-emption. But we will
* a little stronger medicine on the SMP case: The task make be running
* on another CPU.
*/
flags = enter_critical_section();
/* Find for the TCB associated with matching pid */
tcb = (FAR struct task_tcb_s *)sched_gettcb(pid);
#ifndef CONFIG_DISABLE_PTHREAD
if (!tcb || (tcb->cmn.flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
#else
if (!tcb)
#endif
{
/* There is no TCB with this pid or, if there is, it is not a task. */
errcode = ESRCH;
goto errout_with_lock;
}
#ifdef CONFIG_SMP
/* If the task is running on another CPU, then pause that CPU. We can
* then manipulate the TCB of the restarted task and when we resume the
* that CPU, the restart take effect.
*/
cpu = sched_cpu_pause(&tcb->cmn);
#endif /* CONFIG_SMP */
/* Try to recover from any bad states */
task_recover((FAR struct tcb_s *)tcb);
/* Kill any children of this thread */
#ifdef HAVE_GROUP_MEMBERS
(void)group_killchildren(tcb);
#endif
/* Remove the TCB from whatever list it is in. After this point, the TCB
* should no longer be accessible to the system
*/
#ifdef CONFIG_SMP
tasklist = TLIST_HEAD(tcb->cmn.task_state, tcb->cmn.cpu);
#else
tasklist = TLIST_HEAD(tcb->cmn.task_state);
#endif
dq_rem((FAR dq_entry_t *)tcb, tasklist);
tcb->cmn.task_state = TSTATE_TASK_INVALID;
#ifndef CONFIG_DISABLE_SIGNALS
/* Deallocate anything left in the TCB's signal queues */
nxsig_cleanup((FAR struct tcb_s *)tcb); /* Deallocate Signal lists */
tcb->cmn.sigprocmask = NULL_SIGNAL_SET; /* Reset sigprocmask */
#endif
/* Reset the current task priority */
tcb->cmn.sched_priority = tcb->cmn.init_priority;
/* The task should restart with pre-emption disabled and not in a critical
* section.
*/
tcb->cmn.lockcount = 0;
#ifdef CONFIG_SMP
tcb->cmn.irqcount = 0;
#endif
/* Reset the base task priority and the number of pending reprioritizations */
#ifdef CONFIG_PRIORITY_INHERITANCE
tcb->cmn.base_priority = tcb->cmn.init_priority;
# if CONFIG_SEM_NNESTPRIO > 0
tcb->cmn.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((FAR struct tcb_s *)tcb);
/* Add the task to the inactive task list */
dq_addfirst((FAR dq_entry_t *)tcb, (FAR dq_queue_t *)&g_inactivetasks);
tcb->cmn.task_state = TSTATE_TASK_INACTIVE;
#ifdef CONFIG_SMP
/* Resume the paused CPU (if any) */
if (cpu >= 0)
{
ret = up_cpu_resume(cpu);
if (ret < 0)
{
errcode = -ret;
goto errout_with_lock;
}
}
#endif /* CONFIG_SMP */
leave_critical_section(flags);
/* Activate the task. */
ret = task_activate((FAR struct tcb_s *)tcb);
if (ret != OK)
{
(void)task_terminate(pid, true);
errcode = -ret;
goto errout_with_lock;
}
return OK;
errout_with_lock:
leave_critical_section(flags);
errout:
set_errno(errcode);
return ERROR;
}