1/* Copyright (c) 1998-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1998.
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 <unistd.h>
20#include <stdlib.h>
21#include <sys/time.h>
22#include <libc-lock.h>
23#include <rpc/rpc.h>
24
25/* The RPC code is not threadsafe, but new code should be threadsafe. */
26
27__libc_lock_define_initialized (static, createxid_lock)
28
29static pid_t is_initialized;
30static struct drand48_data __rpc_lrand48_data;
31
32unsigned long
33_create_xid (void)
34{
35 long int res;
36
37 __libc_lock_lock (createxid_lock);
38
39 pid_t pid = getpid ();
40 if (is_initialized != pid)
41 {
42 struct timespec now;
43
44 __clock_gettime (CLOCK_REALTIME, &now);
45 __srand48_r (now.tv_sec ^ now.tv_nsec ^ pid,
46 &__rpc_lrand48_data);
47 is_initialized = pid;
48 }
49
50 lrand48_r (&__rpc_lrand48_data, &res);
51
52 __libc_lock_unlock (createxid_lock);
53
54 return res;
55}
56