src/rpc_dtablesize.c

/*
 * 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
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 */

#include <config.h>
#include <unistd.h>

#include <sys/select.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);
}