1 /*
2 *
3 * Copyright (c) International Business Machines Corp., 2009
4 * Copyright (c) 2014 Oracle and/or its affiliates. All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
14 * the GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <fcntl.h>
22 #include <limits.h>
23 #include <sys/types.h>
24 #include "test.h"
25 #include "tst_pid.h"
26 #include "old_safe_file_ops.h"
27
28 #define PID_MAX_PATH "/proc/sys/kernel/pid_max"
29
tst_get_unused_pid_(void (* cleanup_fn)(void))30 pid_t tst_get_unused_pid_(void (*cleanup_fn) (void))
31 {
32 pid_t pid;
33
34 SAFE_FILE_SCANF(cleanup_fn, PID_MAX_PATH, "%d", &pid);
35
36 return pid;
37 }
38
tst_get_free_pids_(void (* cleanup_fn)(void))39 int tst_get_free_pids_(void (*cleanup_fn) (void))
40 {
41 FILE *f;
42 int rc, used_pids, max_pids;
43
44 f = popen("ps -eT | wc -l", "r");
45 if (!f) {
46 tst_resm(TBROK, "Could not run 'ps' to calculate used " "pids");
47 return -1;
48 }
49 rc = fscanf(f, "%i", &used_pids);
50 pclose(f);
51
52 if (rc != 1 || used_pids < 0) {
53 tst_resm(TBROK, "Could not read output of 'ps' to "
54 "calculate used pids");
55 return -1;
56 }
57
58 SAFE_FILE_SCANF(cleanup_fn, PID_MAX_PATH, "%d", &max_pids);
59
60 /* max_pids contains the maximum PID + 1,
61 * used_pids contains used PIDs + 1,
62 * so this additional '1' is eliminated by the substraction */
63 return max_pids - used_pids;
64 }
65