Files
cdesktop/cde/lib/tt/mini_isam/isfcbwatchfd.c
2018-06-30 19:10:10 -06:00

146 lines
3.0 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/*%% (c) Copyright 1993, 1994 Hewlett-Packard Company */
/*%% (c) Copyright 1993, 1994 International Business Machines Corp. */
/*%% (c) Copyright 1993, 1994 Sun Microsystems, Inc. */
/*%% (c) Copyright 1993, 1994 Novell, Inc. */
/*%% $XConsortium: isfcbwatchfd.c /main/3 1995/10/23 11:38:51 rswiston $ */
/*
* Copyright (c) 1988 by Sun Microsystems, Inc.
*/
/*
* isfcbwatchfd.c
*
* Description:
* Watch the limit on UNIX file descriptors used by the FCB module.
*/
#if defined(_AIX)
#define _POSIX_SYSCONF
#endif
#if defined(_AIX)
#define _POSIX_SYSCONF
#endif
#include "isam_impl.h"
#include <sys/time.h>
#include <sys/resource.h>
#ifdef _POSIX_SYSCONF
#include <unistd.h>
#endif /* _POSIX_SYSCONF */
static int _limit = MAXFCB_UNIXFD; /* Imposed limit */
static int _in_use = 0; /* Current number of
* open file descriptors
*/
/*
* _watchfd_incr(n)
*
* Register that n additional UNIX file descriptors were open.
*
* Return the new number of open file descriptors.
*/
int
_watchfd_incr(int n)
{
_in_use += n;
assert(_in_use <= _limit);
return (_in_use);
}
/*
* _watch_decr(n)
*
* Register that n open file descriptors were closed.
*
* Return the new number of open file descriptors.
*/
int
_watchfd_decr(int n)
{
_in_use -= n;
assert(_in_use >= 0);
return (_in_use);
}
/*
* _watch_check()
*
* Return number of fd that are still available.
*/
int
_watchfd_check(void)
{
return (_limit - _in_use);
}
/*
* _watchfd_max_set(n)
*
* Set the maximum number of UNIX fds that may be comsumed by ISAM files.
*/
int
_watchfd_max_set(int n)
{
int oldlimit = _limit;
#ifdef _POSIX_SYSCONF
if (n < 3 || n > sysconf(_SC_OPEN_MAX)) {
#else
int dtab_size = 0;
struct rlimit rl;
if (getrlimit(RLIMIT_NOFILE, &rl) == 0)
dtab_size = rl.rlim_cur;
if (n < 3 || n > dtab_size) {
#endif
_setiserrno2(EBADARG, '9', '0');
return (ISERROR);
}
_limit = n;
return (oldlimit);
}
/*
* _watchfd_max_get()
*
* Get the maximum number of UNIX fds that may be comsumed by ISAM files.
*/
int
_watchfd_max_get(void)
{
return (_limit);
}