aboutsummaryrefslogtreecommitdiff
path: root/support/support_subprocess.c
blob: 89e767ae47e454f191e32f6421cb3a6678e2d432 (plain)
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
/* Create subprocess.
   Copyright (C) 2019-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <stdio.h>
#include <signal.h>
#include <time.h>
#include <sys/wait.h>
#include <stdbool.h>
#include <support/xspawn.h>
#include <support/check.h>
#include <support/xunistd.h>
#include <support/subprocess.h>

static struct support_subprocess
support_subprocess_init (void)
{
  struct support_subprocess result;

  xpipe (result.stdout_pipe);
  TEST_VERIFY (result.stdout_pipe[0] > STDERR_FILENO);
  TEST_VERIFY (result.stdout_pipe[1] > STDERR_FILENO);

  xpipe (result.stderr_pipe);
  TEST_VERIFY (result.stderr_pipe[0] > STDERR_FILENO);
  TEST_VERIFY (result.stderr_pipe[1] > STDERR_FILENO);

  TEST_VERIFY (fflush (stdout) == 0);
  TEST_VERIFY (fflush (stderr) == 0);

  return result;
}

struct support_subprocess
support_subprocess (void (*callback) (void *), void *closure)
{
  struct support_subprocess result = support_subprocess_init ();

  result.pid = xfork ();
  if (result.pid == 0)
    {
      xclose (result.stdout_pipe[0]);
      xclose (result.stderr_pipe[0]);
      xdup2 (result.stdout_pipe[1], STDOUT_FILENO);
      xdup2 (result.stderr_pipe[1], STDERR_FILENO);
      xclose (result.stdout_pipe[1]);
      xclose (result.stderr_pipe[1]);
      callback (closure);
      _exit (0);
    }
  xclose (result.stdout_pipe[1]);
  xclose (result.stderr_pipe[1]);

  return result;
}

struct support_subprocess
support_subprogram (const char *file, char *const argv[])
{
  struct support_subprocess result = support_subprocess_init ();

  posix_spawn_file_actions_t fa;
  /* posix_spawn_file_actions_init does not fail.  */
  posix_spawn_file_actions_init (&fa);

  xposix_spawn_file_actions_addclose (&fa, result.stdout_pipe[0]);
  xposix_spawn_file_actions_addclose (&fa, result.stderr_pipe[0]);
  xposix_spawn_file_actions_adddup2 (&fa, result.stdout_pipe[1], STDOUT_FILENO);
  xposix_spawn_file_actions_adddup2 (&fa, result.stderr_pipe[1], STDERR_FILENO);
  xposix_spawn_file_actions_addclose (&fa, result.stdout_pipe[1]);
  xposix_spawn_file_actions_addclose (&fa, result.stderr_pipe[1]);

  result.pid = xposix_spawn (file, &fa, NULL, argv, environ);

  xclose (result.stdout_pipe[1]);
  xclose (result.stderr_pipe[1]);

  return result;
}

int
support_subprogram_wait (const char *file, char *const argv[])
{
  posix_spawn_file_actions_t fa;

  posix_spawn_file_actions_init (&fa);
  struct support_subprocess res = support_subprocess_init ();

  res.pid = xposix_spawn (file, &fa, NULL, argv, environ);

  return support_process_wait (&res);
}

int
support_process_wait (struct support_subprocess *proc)
{
  xclose (proc->stdout_pipe[0]);
  xclose (proc->stderr_pipe[0]);

  int status;
  xwaitpid (proc->pid, &status, 0);
  return status;
}


static bool
support_process_kill (int pid, int signo, int *status)
{
  /* Kill the whole process group.  */
  kill (-pid, signo);
  /* In case setpgid failed in the child, kill it individually too.  */
  kill (pid, signo);

  /* Wait for it to terminate.  */
  pid_t killed;
  for (int i = 0; i < 5; ++i)
    {
      int status;
      killed = xwaitpid (pid, &status, WNOHANG|WUNTRACED);
      if (killed != 0)
        break;

      /* Delay, give the system time to process the kill.  If the
         nanosleep() call return prematurely, all the better.  We
         won't restart it since this probably means the child process
         finally died.  */
      nanosleep (&((struct timespec) { 0, 100000000 }), NULL);
    }
  if (killed != 0 && killed != pid)
    return false;

  return true;
}

int
support_process_terminate (struct support_subprocess *proc)
{
  xclose (proc->stdout_pipe[0]);
  xclose (proc->stderr_pipe[0]);

  int status;
  pid_t killed = xwaitpid (proc->pid, &status, WNOHANG|WUNTRACED);
  if (killed != 0 && killed == proc->pid)
    return status;

  /* Subprocess is still running, terminate it.  */
  if (!support_process_kill (proc->pid, SIGTERM, &status) )
    support_process_kill (proc->pid, SIGKILL, &status);

  return status;
}