/****************************************************************************
* sched/task_delete.c
*
* Copyright (C) 2007-2009, 2011-2013 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
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*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <nuttx/sched.h>
#include "os_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: task_delete
*
* Description:
* This function causes a specified task to cease to exist. Its stack and
* TCB will be deallocated. This function is the companion to task_create().
* This is the version of the function exposed to the user; it is simply
* a wrapper around the internal, task_terminate function.
*
* The logic in this function only deletes non-running tasks. If the 'pid'
* parameter refers to to the currently runing task, then processing is
* redirected to exit(). This can only happen if a task calls task_delete()
* in order to delete itself.
*
* In fact, this function (and task_terminate) are the final functions
* called all task termination sequences. task_delete may be called
* from:
*
* - task_restart(),
* - pthread_cancel(),
* - and directly from user code.
*
* Other exit paths (exit(), _eixt(), and pthread_exit()) will go through
* task_terminate()
*
* Inputs:
* pid - The task ID of the task to delete. A pid of zero
* signifies the calling task.
*
* Return 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 task_delete(pid_t pid)
{
FAR struct tcb_s *rtcb;
/* Check if the task to delete is the calling task */
rtcb = (FAR struct tcb_s*)g_readytorun.head;
if (pid == 0 || pid == rtcb->pid)
{
/* If it is, then what we really wanted to do was exit. Note that we
* don't bother to unlock the TCB since it will be going away.
*/
exit(EXIT_SUCCESS);
}
/* Then let task_terminate do the heavy lifting */
return task_terminate(pid, false);
}
