xref: /freebsd/lib/libc/rpc/rpc_dtablesize.c (revision a79b71281cd63ad7a6cc43a6d5673a2510b51630)
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";*/
33 static char *rcsid = "$FreeBSD$";
34 #endif
35 
36 #include <sys/types.h>
37 #include <unistd.h>
38 
39 /*
40  * Cache the result of getdtablesize(), so we don't have to do an
41  * expensive system call every time.
42  */
43 /*
44  * XXX In FreeBSD 2.x, you can have the maximum number of open file
45  * descriptors be greater than FD_SETSIZE (which us 256 by default).
46  *
47  * Since old programs tend to use this call to determine the first arg
48  * for select(), having this return > FD_SETSIZE is a Bad Idea(TM)!
49  */
50 int
51 _rpc_dtablesize(void)
52 {
53 	static int size;
54 
55 	if (size == 0) {
56 		size = getdtablesize();
57 		if (size > FD_SETSIZE)
58 			size = FD_SETSIZE;
59 	}
60 	return (size);
61 }
62