| 1 | /* Copyright (c) 1998-2022 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 | |
| 28 | static pid_t is_initialized; |
| 29 | static struct drand48_data __rpc_lrand48_data; |
| 30 | |
| 31 | unsigned 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 (seedval: now.tv_sec ^ now.tv_nsec ^ pid, |
| 45 | buffer: &__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 |