lib/libc/rpc/rpc_dtablesize.c

   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  * @(#)rpc_dtablesize.c 1.2 87/08/11 Copyr 1987 Sun Micro
  30  * @(#)rpc_dtablesize.c 2.1 88/07/29 4.0 RPCSRC
  31  * $NetBSD: rpc_dtablesize.c,v 1.14 1998/11/15 17:32:43 christos Exp $
  32  * $FreeBSD: src/lib/libc/rpc/rpc_dtablesize.c,v 1.15 2004/10/16 06:11:35 obrien Exp $
  33  * $DragonFly: src/lib/libc/rpc/rpc_dtablesize.c,v 1.3 2005/01/31 22:29:38 dillon Exp $
  34  */
  35
  36 #include "namespace.h"
  37 #include <unistd.h>
  38 #include "un-namespace.h"
  39
  40 int _rpc_dtablesize(void);      /* XXX */
  41
  42 /*
  43  * Cache the result of getdtablesize(), so we don't have to do an
  44  * expensive system call every time.
  45  */
  46 /*
  47  * XXX In FreeBSD 2.x, you can have the maximum number of open file
  48  * descriptors be greater than FD_SETSIZE (which us 256 by default).
  49  *
  50  * Since old programs tend to use this call to determine the first arg
  51  * for _select(), having this return > FD_SETSIZE is a Bad Idea(TM)!
  52  */
  53 int
  54 _rpc_dtablesize(void)
  55 {
  56         static int size;
  57
  58         if (size == 0) {
  59                 size = getdtablesize();
  60                 if (size > FD_SETSIZE)
  61                         size = FD_SETSIZE;
  62         }
  63         return (size);
  64 }