1/* Copyright (C) 1991-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <unistd.h>
20#include <hurd.h>
21#include <hurd/fd.h>
22#include <hurd/resource.h>
23
24/* Return the maximum number of file descriptors the current process
25 could possibly have (until it raises the resource limit). */
26int
27__getdtablesize (void)
28{
29 rlim_t limit;
30
31 HURD_CRITICAL_BEGIN;
32 __mutex_lock (&_hurd_rlimit_lock);
33 limit = _hurd_rlimits[RLIMIT_NOFILE].rlim_cur;
34 __mutex_unlock (&_hurd_rlimit_lock);
35 HURD_CRITICAL_END;
36
37 /* RLIM_INFINITY is not meaningful to our caller. -1 is a good choice
38 because `sysconf (_SC_OPEN_MAX)' calls us, and -1 from sysconf means
39 "no determinable limit". */
40 return limit == RLIM_INFINITY ? -1 : (int) limit;
41}
42
43weak_alias (__getdtablesize, getdtablesize)
44

source code of glibc/sysdeps/mach/hurd/getdtsz.c