1 /*
2 * Copyright (c) 2021 Alexey Dobriyan <adobriyan@gmail.com>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16 // Test that /proc/*/task never contains "".
17 #include <sys/types.h>
18 #include <dirent.h>
19 #include <signal.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <pthread.h>
25
26 static pid_t pid = -1;
27
28 static void atexit_hook(void)
29 {
30 if (pid > 0) {
31 kill(pid, SIGKILL);
32 }
33 }
34
35 static void *f(void *_)
36 {
37 return NULL;
38 }
39
40 static void sigalrm(int _)
41 {
42 exit(0);
43 }
44
45 int main(void)
46 {
47 pid = fork();
48 if (pid == 0) {
49 /* child */
50 while (1) {
51 pthread_t pth;
52 pthread_create(&pth, NULL, f, NULL);
53 pthread_join(pth, NULL);
54 }
55 } else if (pid > 0) {
56 /* parent */
57 atexit(atexit_hook);
58
59 char buf[64];
60 snprintf(buf, sizeof(buf), "/proc/%u/task", pid);
61
62 signal(SIGALRM, sigalrm);
63 alarm(1);
64
65 while (1) {
66 DIR *d = opendir(buf);
67 struct dirent *de;
68 while ((de = readdir(d))) {
69 if (strcmp(de->d_name, "") == 0) {
70 exit(1);
71 }
72 }
73 closedir(d);
74 }
75
76 return 0;
77 } else {
78 perror("fork");
79 return 1;
80 }
81 }
82
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