xref: /freebsd/lib/libc/rpc/rpc_dtablesize.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*	$NetBSD: rpc_dtablesize.c,v 1.14 1998/11/15 17:32:43 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009, Sun Microsystems, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are met:
9  * - Redistributions of source code must retain the above copyright notice,
10  *   this list of conditions and the following disclaimer.
11  * - Redistributions in binary form must reproduce the above copyright notice,
12  *   this list of conditions and the following disclaimer in the documentation
13  *   and/or other materials provided with the distribution.
14  * - Neither the name of Sun Microsystems, Inc. nor the names of its
15  *   contributors may be used to endorse or promote products derived
16  *   from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #if defined(LIBC_SCCS) && !defined(lint)
32 static char *sccsid2 = "@(#)rpc_dtablesize.c 1.2 87/08/11 Copyr 1987 Sun Micro";
33 static char *sccsid = "@(#)rpc_dtablesize.c	2.1 88/07/29 4.0 RPCSRC";
34 #endif
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "namespace.h"
39 #include <unistd.h>
40 #include "un-namespace.h"
41 
42 int _rpc_dtablesize(void);	/* XXX */
43 
44 /*
45  * Cache the result of getdtablesize(), so we don't have to do an
46  * expensive system call every time.
47  */
48 /*
49  * XXX In FreeBSD 2.x, you can have the maximum number of open file
50  * descriptors be greater than FD_SETSIZE (which us 256 by default).
51  *
52  * Since old programs tend to use this call to determine the first arg
53  * for _select(), having this return > FD_SETSIZE is a Bad Idea(TM)!
54  */
55 int
56 _rpc_dtablesize(void)
57 {
58 	static int size;
59 
60 	if (size == 0) {
61 		size = getdtablesize();
62 		if (size > FD_SETSIZE)
63 			size = FD_SETSIZE;
64 	}
65 	return (size);
66 }
67