From 6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:29:51 +0200 Subject: Adding upstream version 2.06. Signed-off-by: Daniel Baumann --- grub-core/lib/gnulib/getdtablesize.c | 124 +++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 grub-core/lib/gnulib/getdtablesize.c (limited to 'grub-core/lib/gnulib/getdtablesize.c') diff --git a/grub-core/lib/gnulib/getdtablesize.c b/grub-core/lib/gnulib/getdtablesize.c new file mode 100644 index 0000000..03a9243 --- /dev/null +++ b/grub-core/lib/gnulib/getdtablesize.c @@ -0,0 +1,124 @@ +/* getdtablesize() function: Return maximum possible file descriptor value + 1. + Copyright (C) 2008-2019 Free Software Foundation, Inc. + Written by Bruno Haible , 2008. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include + +/* Specification. */ +#include + +#if defined _WIN32 && ! defined __CYGWIN__ + +# include + +# if HAVE_MSVC_INVALID_PARAMETER_HANDLER +# include "msvc-inval.h" +# endif + +# if HAVE_MSVC_INVALID_PARAMETER_HANDLER +static int +_setmaxstdio_nothrow (int newmax) +{ + int result; + + TRY_MSVC_INVAL + { + result = _setmaxstdio (newmax); + } + CATCH_MSVC_INVAL + { + result = -1; + } + DONE_MSVC_INVAL; + + return result; +} +# else +# define _setmaxstdio_nothrow _setmaxstdio +# endif + +/* Cache for the previous getdtablesize () result. Safe to cache because + Windows also lacks setrlimit. */ +static int dtablesize; + +int +getdtablesize (void) +{ + if (dtablesize == 0) + { + /* We are looking for the number N such that the valid file descriptors + are 0..N-1. It can be obtained through a loop as follows: + { + int fd; + for (fd = 3; fd < 65536; fd++) + if (dup2 (0, fd) == -1) + break; + return fd; + } + On Windows XP, the result is 2048. + The drawback of this loop is that it allocates memory for a libc + internal array that is never freed. + + The number N can also be obtained as the upper bound for + _getmaxstdio (). _getmaxstdio () returns the maximum number of open + FILE objects. The sanity check in _setmaxstdio reveals the maximum + number of file descriptors. This too allocates memory, but it is + freed when we call _setmaxstdio with the original value. */ + int orig_max_stdio = _getmaxstdio (); + unsigned int bound; + for (bound = 0x10000; _setmaxstdio_nothrow (bound) < 0; bound = bound / 2) + ; + _setmaxstdio_nothrow (orig_max_stdio); + dtablesize = bound; + } + return dtablesize; +} + +#else + +# include +# include + +# ifndef RLIM_SAVED_CUR +# define RLIM_SAVED_CUR RLIM_INFINITY +# endif +# ifndef RLIM_SAVED_MAX +# define RLIM_SAVED_MAX RLIM_INFINITY +# endif + +# ifdef __CYGWIN__ + /* Cygwin 1.7.25 auto-increases the RLIMIT_NOFILE soft limit until it + hits the compile-time constant hard limit of 3200. We might as + well just report the hard limit. */ +# define rlim_cur rlim_max +# endif + +int +getdtablesize (void) +{ + struct rlimit lim; + + if (getrlimit (RLIMIT_NOFILE, &lim) == 0 + && 0 <= lim.rlim_cur && lim.rlim_cur <= INT_MAX + && lim.rlim_cur != RLIM_INFINITY + && lim.rlim_cur != RLIM_SAVED_CUR + && lim.rlim_cur != RLIM_SAVED_MAX) + return lim.rlim_cur; + + return INT_MAX; +} + +#endif -- cgit v1.2.3