incubator-nuttx/sched/task/task_terminate.c

125 lines
4.0 KiB
C

/****************************************************************************
* sched/task/task_terminate.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 <assert.h>
#include <errno.h>
#include <nuttx/queue.h>
#include <nuttx/sched.h>
#include <nuttx/irq.h>
#include <nuttx/sched_note.h>
#include "sched/sched.h"
#include "signal/signal.h"
#include "task/task.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxtask_terminate
*
* Description:
* This function causes a specified task to cease to exist. Its stack and
* TCB will be deallocated. This function is the internal implementation
* of the task_delete() function. It includes and additional parameter
* to determine if blocking is permitted or not.
*
* This function is the final function called all task termination
* sequences. nxtask_terminate() is called only from task_delete() and
* from nxtask_exit().
*
* The path through nxtask_exit() supports the final stops of the exit(),
* _exit(), and pthread_exit
*
* - pthread_exit(). Calls _exit()
* - exit(). Calls _exit()
* - _exit(). Calls nxtask_exit() making the currently running task
* non-running. nxtask_exit then calls nxtask_terminate() to terminate
* the non-running task.
*
* Input Parameters:
* pid - The task ID of the task to delete. A pid of zero
* signifies the calling task.
*
* Returned Value:
* OK on success; or ERROR on failure
*
* This function can fail if the provided pid does not correspond to a
* task (errno is not set)
*
****************************************************************************/
int nxtask_terminate(pid_t pid)
{
FAR struct tcb_s *dtcb;
uint8_t task_state;
irqstate_t flags;
flags = enter_critical_section();
/* Find for the TCB associated with matching PID */
dtcb = nxsched_get_tcb(pid);
if (!dtcb)
{
leave_critical_section(flags);
return -ESRCH;
}
/* Remove dtcb from tasklist, let remove_readtorun() do the job */
task_state = dtcb->task_state;
nxsched_remove_readytorun(dtcb, false);
dtcb->task_state = task_state;
leave_critical_section(flags);
/* Perform common task termination logic. We need to do
* this as early as possible so that higher level clean-up logic
* can run in a healthy tasking environment.
*
* I suppose EXIT_SUCCESS is an appropriate return value???
*/
nxtask_exithook(dtcb, EXIT_SUCCESS);
/* Since all tasks pass through this function as the final step in their
* exit sequence, this is an appropriate place to inform any
* instrumentation layer that the task no longer exists.
*/
sched_note_stop(dtcb);
/* Deallocate its TCB */
return nxsched_release_tcb(dtcb, dtcb->flags & TCB_FLAG_TTYPE_MASK);
}