1/* Copyright (c) 1998-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <unistd.h>
19#include <stdlib.h>
20#include <sys/time.h>
21#include <libc-lock.h>
22#include <rpc/rpc.h>
23
24/* The RPC code is not threadsafe, but new code should be threadsafe. */
25
26__libc_lock_define_initialized (static, createxid_lock)
27
28static pid_t is_initialized;
29static struct drand48_data __rpc_lrand48_data;
30
31unsigned long
32_create_xid (void)
33{
34 long int res;
35
36 __libc_lock_lock (createxid_lock);
37
38 pid_t pid = getpid ();
39 if (is_initialized != pid)
40 {
41 struct timespec now;
42
43 __clock_gettime (CLOCK_REALTIME, &now);
44 __srand48_r (now.tv_sec ^ now.tv_nsec ^ pid,
45 &__rpc_lrand48_data);
46 is_initialized = pid;
47 }
48
49 lrand48_r (&__rpc_lrand48_data, &res);
50
51 __libc_lock_unlock (createxid_lock);
52
53 return res;
54}
55