summaryrefslogtreecommitdiff
path: root/nuttx/sched/task/task_delete.c
blob: ae5ab231f654f649bfbddd211d9cd193370e7809 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/****************************************************************************
 * sched/task/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
 * 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 <stdlib.h>

#include <nuttx/sched.h>

#include "sched/sched.h"
#include "task/task.h"

/****************************************************************************
 * Pre-processor 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);
}