blob: d3c9638e7516dbfbdc910abc52d2aa96dcb85ba4 [file] [log] [blame]
/*
*
* Copyright (c) International Business Machines Corp., 2009
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* DESCRIPTION
* get_max_pids(): Return the maximum number of pids for this system by
* reading /proc/sys/kernel/pid_max
*
* get_free_pids(): Return number of free pids by subtracting the number
* of pids currently used ('ps -eT') from max_pids
*/
#include <fcntl.h>
#include <limits.h>
#include <sys/types.h>
#include "test.h"
#define BUFSIZE 512
int get_max_pids(void)
{
#ifdef __linux__
FILE *f;
char buf[BUFSIZE];
f = fopen("/proc/sys/kernel/pid_max", "r");
if (!f) {
tst_resm(TBROK, "Could not open /proc/sys/kernel/pid_max");
return -1;
}
if (!fgets(buf, BUFSIZE, f)) {
fclose(f);
tst_resm(TBROK, "Could not read /proc/sys/kernel/pid_max");
return -1;
}
fclose(f);
return atoi(buf);
#else
return SHRT_MAX;
#endif
}
int get_free_pids(void)
{
FILE *f;
int rc, used_pids, max_pids;
f = popen("ps -eT | wc -l", "r");
if (!f) {
tst_resm(TBROK, "Could not run 'ps' to calculate used "
"pids");
return -1;
}
rc = fscanf(f, "%i", &used_pids);
pclose(f);
if (rc != 1 || used_pids < 0) {
tst_resm(TBROK, "Could not read output of 'ps' to "
"calculate used pids");
return -1;
}
max_pids = get_max_pids();
if (max_pids < 0)
return -1;
return max_pids - used_pids;
}