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 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 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
