1/* Create subprocess.
2 Copyright (C) 2019-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <stdio.h>
20#include <signal.h>
21#include <time.h>
22#include <sys/wait.h>
23#include <stdbool.h>
24#include <support/xspawn.h>
25#include <support/check.h>
26#include <support/xunistd.h>
27#include <support/subprocess.h>
28
29static struct support_subprocess
30support_suprocess_init (void)
31{
32 struct support_subprocess result;
33
34 xpipe (result.stdout_pipe);
35 TEST_VERIFY (result.stdout_pipe[0] > STDERR_FILENO);
36 TEST_VERIFY (result.stdout_pipe[1] > STDERR_FILENO);
37
38 xpipe (result.stderr_pipe);
39 TEST_VERIFY (result.stderr_pipe[0] > STDERR_FILENO);
40 TEST_VERIFY (result.stderr_pipe[1] > STDERR_FILENO);
41
42 TEST_VERIFY (fflush (stdout) == 0);
43 TEST_VERIFY (fflush (stderr) == 0);
44
45 return result;
46}
47
48struct support_subprocess
49support_subprocess (void (*callback) (void *), void *closure)
50{
51 struct support_subprocess result = support_suprocess_init ();
52
53 result.pid = xfork ();
54 if (result.pid == 0)
55 {
56 xclose (result.stdout_pipe[0]);
57 xclose (result.stderr_pipe[0]);
58 xdup2 (result.stdout_pipe[1], STDOUT_FILENO);
59 xdup2 (result.stderr_pipe[1], STDERR_FILENO);
60 xclose (result.stdout_pipe[1]);
61 xclose (result.stderr_pipe[1]);
62 callback (closure);
63 _exit (0);
64 }
65 xclose (result.stdout_pipe[1]);
66 xclose (result.stderr_pipe[1]);
67
68 return result;
69}
70
71struct support_subprocess
72support_subprogram (const char *file, char *const argv[])
73{
74 struct support_subprocess result = support_suprocess_init ();
75
76 posix_spawn_file_actions_t fa;
77 /* posix_spawn_file_actions_init does not fail. */
78 posix_spawn_file_actions_init (&fa);
79
80 xposix_spawn_file_actions_addclose (&fa, result.stdout_pipe[0]);
81 xposix_spawn_file_actions_addclose (&fa, result.stderr_pipe[0]);
82 xposix_spawn_file_actions_adddup2 (&fa, result.stdout_pipe[1], STDOUT_FILENO);
83 xposix_spawn_file_actions_adddup2 (&fa, result.stderr_pipe[1], STDERR_FILENO);
84 xposix_spawn_file_actions_addclose (&fa, result.stdout_pipe[1]);
85 xposix_spawn_file_actions_addclose (&fa, result.stderr_pipe[1]);
86
87 result.pid = xposix_spawn (file, &fa, NULL, argv, NULL);
88
89 xclose (result.stdout_pipe[1]);
90 xclose (result.stderr_pipe[1]);
91
92 return result;
93}
94
95int
96support_process_wait (struct support_subprocess *proc)
97{
98 xclose (proc->stdout_pipe[0]);
99 xclose (proc->stderr_pipe[0]);
100
101 int status;
102 xwaitpid (proc->pid, &status, 0);
103 return status;
104}
105
106
107static bool
108support_process_kill (int pid, int signo, int *status)
109{
110 /* Kill the whole process group. */
111 kill (-pid, signo);
112 /* In case setpgid failed in the child, kill it individually too. */
113 kill (pid, signo);
114
115 /* Wait for it to terminate. */
116 pid_t killed;
117 for (int i = 0; i < 5; ++i)
118 {
119 int status;
120 killed = xwaitpid (pid, &status, WNOHANG|WUNTRACED);
121 if (killed != 0)
122 break;
123
124 /* Delay, give the system time to process the kill. If the
125 nanosleep() call return prematurely, all the better. We
126 won't restart it since this probably means the child process
127 finally died. */
128 nanosleep (&((struct timespec) { 0, 100000000 }), NULL);
129 }
130 if (killed != 0 && killed != pid)
131 return false;
132
133 return true;
134}
135
136int
137support_process_terminate (struct support_subprocess *proc)
138{
139 xclose (proc->stdout_pipe[0]);
140 xclose (proc->stderr_pipe[0]);
141
142 int status;
143 pid_t killed = xwaitpid (proc->pid, &status, WNOHANG|WUNTRACED);
144 if (killed != 0 && killed == proc->pid)
145 return status;
146
147 /* Subprocess is still running, terminate it. */
148 if (!support_process_kill (proc->pid, SIGTERM, &status) )
149 support_process_kill (proc->pid, SIGKILL, &status);
150
151 return status;
152}
153