rpc_dtablesize.c revision 8870 
1/*
2 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3 * unrestricted use provided that this legend is included on all tape
4 * media and as a part of the software program in whole or part.  Users
5 * may copy or modify Sun RPC without charge, but are not authorized
6 * to license or distribute it to anyone else except as part of a product or
7 * program developed by the user.
8 *
9 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12 *
13 * Sun RPC is provided with no support and without any obligation on the
14 * part of Sun Microsystems, Inc. to assist in its use, correction,
15 * modification or enhancement.
16 *
17 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19 * OR ANY PART THEREOF.
20 *
21 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22 * or profits or other special, indirect and consequential damages, even if
23 * Sun has been advised of the possibility of such damages.
24 *
25 * Sun Microsystems, Inc.
26 * 2550 Garcia Avenue
27 * Mountain View, California  94043
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31/*static char *sccsid = "from: @(#)rpc_dtablesize.c 1.2 87/08/11 Copyr 1987 Sun Micro";*/
32/*static char *sccsid = "from: @(#)rpc_dtablesize.c	2.1 88/07/29 4.0 RPCSRC";*/
33static char *rcsid = "rpc_dtablesize.c,v 1.1 1994/08/07 18:36:02 wollman Exp";
34#endif
35
36#include <sys/types.h>
37
38/*
39 * Cache the result of getdtablesize(), so we don't have to do an
40 * expensive system call every time.
41 */
42/*
43 * XXX In FreeBSD 2.x, you can have the maximum number of open file
44 * descriptors be greater than FD_SETSIZE (which us 256 by default).
45 * This can lead to many RPC functions getting back an EINVAL from
46 * select() and bombing all over the place.
47 *
48 * You can apparently get select() to handle values larger than 256
49 * by patching the kernel, but most people aren't likely to know
50 * that. Clamping this function at 256 is a kludge, but it'll have to
51 * do until select()'s descriptor table size can be adjusted dynamically.
52 */
53_rpc_dtablesize()
54{
55	static int size;
56
57	if (size == 0) {
58		size = getdtablesize();
59		if (size > FD_SETSIZE)
60			size = FD_SETSIZE;
61	}
62	return (size);
63}
64