summaryrefslogtreecommitdiff
path: root/nuttx/sched/sched_setuptaskfiles.c
blob: fe0b14143d45bc6deaa174d7d433c871b6699a4c (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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
/****************************************************************************
 * sched/sched_setuptaskfiles.c
 *
 *   Copyright (C) 2007-2008, 2010, 2012 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 <sched.h>
#include <errno.h>

#include <nuttx/fs/fs.h>
#include <nuttx/net/net.h>

#include "os_internal.h"

#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/* Determine how many file descriptors to clone.  If CONFIG_FDCLONE_DISABLE
 * is set, no file descriptors will be cloned.  If CONFIG_FDCLONE_STDIO is
 * set, only the first three descriptors (stdin, stdout, and stderr) will
 * be cloned.  Otherwise all file descriptors will be cloned.
 */

#if defined(CONFIG_FDCLONE_STDIO) && CONFIG_NFILE_DESCRIPTORS > 3
#  define NFDS_TOCLONE 3
#else
#  define NFDS_TOCLONE CONFIG_NFILE_DESCRIPTORS
#endif

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: sched_dupfiles
 *
 * Description:
 *   Duplicate parent task's file descriptors.
 *
 * Input Parameters:
 *   tcb - tcb of the new task.
 *
 * Return Value:
 *   None
 *
 ****************************************************************************/

#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_FDCLONE_DISABLE)
static inline void sched_dupfiles(FAR _TCB *tcb)
{
  /* The parent task is the one at the head of the ready-to-run list */

  FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head;
  FAR struct file *parent;
  FAR struct file *child;
  int i;

  /* Duplicate the file descriptors.  This will be either all of the
   * file descriptors or just the first three (stdin, stdout, and stderr)
   * if CONFIG_FDCLONE_STDIO is defined.  NFSDS_TOCLONE is set
   * accordingly above.
   */

  if (rtcb->filelist)
    {
      /* Get pointers to the parent and child task file lists */

      parent = rtcb->filelist->fl_files;
      child  = tcb->filelist->fl_files;

      /* Check each file in the parent file list */

      for (i = 0; i < NFDS_TOCLONE; i++)
        {
          /* Check if this file is opened by the parent.  We can tell if
           * if the file is open because it contain a reference to a non-NULL
           * i-node structure.
           */

          if (parent[i].f_inode)
            {
              /* Yes... duplicate it for the child */

              (void)files_dup(&parent[i], &child[i]);
            }
        }
    }
}
#else /* CONFIG_NFILE_DESCRIPTORS && !CONFIG_FDCLONE_DISABLE */
#  define sched_dupfiles(tcb)
#endif /* CONFIG_NFILE_DESCRIPTORS && !CONFIG_FDCLONE_DISABLE */

/****************************************************************************
 * Name: sched_dupsockets
 *
 * Description:
 *   Duplicate the parent task's socket descriptors.
 *
 * Input Parameters:
 *   tcb - tcb of the new task.
 *
 * Return Value:
 *   None
 *
 ****************************************************************************/

#if CONFIG_NSOCKET_DESCRIPTORS > 0 && !defined(CONFIG_SDCLONE_DISABLE)
static inline void sched_dupsockets(FAR _TCB *tcb)
{
  /* The parent task is the one at the head of the ready-to-run list */

  FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head;
  FAR struct socket *parent;
  FAR struct socket *child;
  int i;

 /* Duplicate the socket descriptors of all sockets opened by the parent
  * task.
  */

  if (rtcb->sockets)
    {
      /* Get pointers to the parent and child task socket lists */

      parent = rtcb->sockets->sl_sockets;
      child  = tcb->sockets->sl_sockets;

      /* Check each socket in the parent socket list */

      for (i = 0; i < CONFIG_NSOCKET_DESCRIPTORS; i++)
        {
          /* Check if this parent socket is allocated.  We can tell if the
           * socket is allocated because it will have a positive, non-zero
           * reference count.
           */

          if (parent[i].s_crefs > 0)
            {
              /* Yes... duplicate it for the child */

              (void)net_clone(&parent[i], &child[i]);
            }
        }
    }
}
#else /* CONFIG_NSOCKET_DESCRIPTORS && !CONFIG_SDCLONE_DISABLE */
#  define sched_dupsockets(tcb)
#endif /* CONFIG_NSOCKET_DESCRIPTORS && !CONFIG_SDCLONE_DISABLE */

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: sched_setuptaskfiles
 *
 * Description:
 *   Configure a newly allocated TCB so that it will inherit
 *   file descriptors and streams from the parent task.
 *
 * Parameters:
 *   tcb - tcb of the new task.
 *
 * Return Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

int sched_setuptaskfiles(FAR _TCB *tcb)
{
  /* Allocate file descriptors for the TCB */

#if CONFIG_NFILE_DESCRIPTORS > 0
  tcb->filelist = files_alloclist();
  if (!tcb->filelist)
    {
      return -ENOMEM;
    }
#endif

  /* Allocate socket descriptors for the TCB */

#if CONFIG_NSOCKET_DESCRIPTORS > 0
  tcb->sockets = net_alloclist();
  if (!tcb->sockets)
    {
      return -ENOMEM;
    }
#endif

  /* Duplicate the parent task's file descriptors */

  sched_dupfiles(tcb);

  /* Duplicate the parent task's socket descriptors */

  sched_dupsockets(tcb);

  /* Allocate file/socket streams for the new TCB */

#if CONFIG_NFILE_STREAMS > 0
  return sched_setupstreams(tcb);
#else
  return OK;
#endif
}

#endif /* CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0*/