incubator-nuttx/sched/task/task_restart.c

250 lines
6.9 KiB
C

/****************************************************************************
* sched/task/task_restart.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 <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"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: nxtask_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; or negated errno 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.
*
****************************************************************************/
#ifndef CONFIG_BUILD_KERNEL
static int nxtask_restart(pid_t pid)
{
FAR struct tcb_s *rtcb;
FAR struct task_tcb_s *tcb;
FAR dq_queue_t *tasklist;
irqstate_t flags;
int ret;
#ifdef CONFIG_SMP
int cpu;
#endif
/* Check if the task to restart is the calling task */
rtcb = this_task();
if ((pid == 0) || (pid == rtcb->pid))
{
/* Not implemented */
ret = -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 *)nxsched_get_tcb(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. */
ret = -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 = nxsched_pause_cpu(&tcb->cmn);
#endif /* CONFIG_SMP */
/* Try to recover from any bad states */
nxtask_recover((FAR struct tcb_s *)tcb);
/* Kill any children of this thread */
#ifdef HAVE_GROUP_MEMBERS
group_kill_children((FAR struct tcb_s *)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, tcb->cmn.cpu);
#else
tasklist = TLIST_HEAD(&tcb->cmn);
#endif
dq_rem((FAR dq_entry_t *)tcb, tasklist);
tcb->cmn.task_state = TSTATE_TASK_INVALID;
/* Deallocate anything left in the TCB's signal queues */
nxsig_cleanup((FAR struct tcb_s *)tcb); /* Deallocate Signal lists */
sigemptyset(&tcb->cmn.sigprocmask); /* Reset sigprocmask */
/* 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;
tcb->cmn.boost_priority = 0;
#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, list_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)
{
goto errout_with_lock;
}
}
#endif /* CONFIG_SMP */
leave_critical_section(flags);
/* Activate the task. */
nxtask_activate((FAR struct tcb_s *)tcb);
return OK;
errout_with_lock:
leave_critical_section(flags);
errout:
return ret;
}
/****************************************************************************
* 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)
{
int ret = nxtask_restart(pid);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
return ret;
}
#endif