rpc_dtablesize.c revision 330897 
1/*	$NetBSD: rpc_dtablesize.c,v 1.14 1998/11/15 17:32:43 christos Exp $	*/
2
3/*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 2009, Sun Microsystems, Inc.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 * - Redistributions of source code must retain the above copyright notice,
12 *   this list of conditions and the following disclaimer.
13 * - Redistributions in binary form must reproduce the above copyright notice,
14 *   this list of conditions and the following disclaimer in the documentation
15 *   and/or other materials provided with the distribution.
16 * - Neither the name of Sun Microsystems, Inc. nor the names of its
17 *   contributors may be used to endorse or promote products derived
18 *   from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#if defined(LIBC_SCCS) && !defined(lint)
34static char *sccsid2 = "@(#)rpc_dtablesize.c 1.2 87/08/11 Copyr 1987 Sun Micro";
35static char *sccsid = "@(#)rpc_dtablesize.c	2.1 88/07/29 4.0 RPCSRC";
36#endif
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: stable/11/lib/libc/rpc/rpc_dtablesize.c 330897 2018-03-14 03:19:51Z eadler $");
39
40#include "namespace.h"
41#include <unistd.h>
42#include "un-namespace.h"
43
44int _rpc_dtablesize(void);	/* XXX */
45
46/*
47 * Cache the result of getdtablesize(), so we don't have to do an
48 * expensive system call every time.
49 */
50/*
51 * XXX In FreeBSD 2.x, you can have the maximum number of open file
52 * descriptors be greater than FD_SETSIZE (which us 256 by default).
53 *
54 * Since old programs tend to use this call to determine the first arg
55 * for _select(), having this return > FD_SETSIZE is a Bad Idea(TM)!
56 */
57int
58_rpc_dtablesize(void)
59{
60	static int size;
61
62	if (size == 0) {
63		size = getdtablesize();
64		if (size > FD_SETSIZE)
65			size = FD_SETSIZE;
66	}
67	return (size);
68}
69