xref: /freebsd/lib/libc/rpc/rpc_dtablesize.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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)
34 static char *sccsid2 = "@(#)rpc_dtablesize.c 1.2 87/08/11 Copyr 1987 Sun Micro";
35 static char *sccsid = "@(#)rpc_dtablesize.c	2.1 88/07/29 4.0 RPCSRC";
36 #endif
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "namespace.h"
41 #include <unistd.h>
42 #include "un-namespace.h"
43 
44 int _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  */
57 int
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