xref: /freebsd-11-stable/lib/libc/rpc/rpc_dtablesize.c

/*	$NetBSD: rpc_dtablesize.c,v 1.14 1998/11/15 17:32:43 christos Exp $	*/

/*-
 * Copyright (c) 2009, Sun Microsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * - Neither the name of Sun Microsystems, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char *sccsid2 = "@(#)rpc_dtablesize.c 1.2 87/08/11 Copyr 1987 Sun Micro";
static char *sccsid = "@(#)rpc_dtablesize.c	2.1 88/07/29 4.0 RPCSRC";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "namespace.h"
#include <unistd.h>
#include "un-namespace.h"

int _rpc_dtablesize(void);	/* XXX */

/*
 * Cache the result of getdtablesize(), so we don't have to do an
 * expensive system call every time.
 */
/*
 * XXX In FreeBSD 2.x, you can have the maximum number of open file
 * descriptors be greater than FD_SETSIZE (which us 256 by default).
 *
 * Since old programs tend to use this call to determine the first arg
 * for _select(), having this return > FD_SETSIZE is a Bad Idea(TM)!
 */
int
_rpc_dtablesize(void)
{
	static int size;

	if (size == 0) {
		size = getdtablesize();
		if (size > FD_SETSIZE)
			size = FD_SETSIZE;
	}
	return (size);
}