/**************************************************************************** * sched/task/task_restart.c * * Copyright (C) 2007, 2009, 2012-2013, 2016, 2018 Gregory Nutt. All * rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #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 */ nxtask_recover((FAR struct tcb_s *)tcb); /* Kill any children of this thread */ #ifdef HAVE_GROUP_MEMBERS 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; /* 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 */ /* 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) { nxtask_terminate(pid, true); errcode = -ret; goto errout_with_lock; } return OK; errout_with_lock: leave_critical_section(flags); errout: set_errno(errcode); return ERROR; }