glibc/sunrpc/create_xid.c

56 lines
1.6 KiB
C

/* Copyright (c) 1998-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <stdlib.h>
#include <sys/time.h>
#include <bits/libc-lock.h>
#include <rpc/rpc.h>
/* The RPC code is not threadsafe, but new code should be threadsafe. */
__libc_lock_define_initialized (static, createxid_lock)
static pid_t is_initialized;
static struct drand48_data __rpc_lrand48_data;
unsigned long
_create_xid (void)
{
long int res;
__libc_lock_lock (createxid_lock);
pid_t pid = getpid ();
if (is_initialized != pid)
{
struct timeval now;
__gettimeofday (&now, (struct timezone *) 0);
__srand48_r (now.tv_sec ^ now.tv_usec ^ pid,
&__rpc_lrand48_data);
is_initialized = pid;
}
lrand48_r (&__rpc_lrand48_data, &res);
__libc_lock_unlock (createxid_lock);
return res;
}