1  /* Copyright (C) 1991-2023 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).  */
      26  int
      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  
      43  weak_alias (__getdtablesize, getdtablesize)