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 _create_xid(void)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