mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-28 10:56:36 +00:00
79f15092b9
This incorporates:
2018-05-21 crypto: omit stream ops Emacs doesn’t need
2018-05-13 truncate: Fix compilation error on Android
2018-05-13 imaxdiv: Fix compilation error on Android
2018-05-13 Support selective inclusion of recent mingw.org headers
2018-05-13 Add cross-compilation guesses for Linux systems sans glibc
2018-05-13 stdioext: Fix compilation errors with newer Android headers
2018-05-07 af_alg: Pacify --enable-gcc-warnings
2018-05-06 af_alg: Fix bug with streams that are not at position 0
2018-05-06 Followup to 'af_alg: New module'
2018-05-05 crypto/{md5,sha1,sha256,sha512}: simplify
2018-05-05 af_alg: New module
2018-05-05 af_alg: Improve function signature
2018-04-28 md5sum: Use AF_ALG when available
2018-04-28 sha512sum: Use AF_ALG when available
2018-04-28 sha256sum: Use AF_ALG when available
2018-04-28 sha1sum: Use AF_ALG when available
2018-05-05 all: Replace more http URLs by https URLs
2018-05-03 maint: port more modules to GCC 8
2018-05-03 Simplify code; drop support for Borland C++ on Windows
* admin/merge-gnulib (GNULIB_MODULES): Use crypto/md5-buffer
rather than crypto/md5, since Emacs doesn’t use the stream
operations that in recent Gnulib pull in other stuff Emacs doesn’t
need. Similarly for crypto/sha1-buffer, crypto/sha256-buffer,
crypto/sha512-buffer.
* build-aux/config.guess, build-aux/config.sub, lib/dosname.h:
* lib/dup2.c, lib/errno.in.h, lib/euidaccess.c, lib/fcntl.c:
* lib/fcntl.in.h, lib/fpending.c, lib/fsync.c, lib/getdtablesize.c:
* lib/getopt.c, lib/gettimeofday.c, lib/inttypes.in.h, lib/md5.c:
* lib/md5.h, lib/open.c, lib/pipe2.c, lib/putenv.c, lib/sha1.c:
* lib/sha1.h, lib/sha256.c, lib/sha256.h, lib/sha512.c:
* lib/sha512.h, lib/stat-time.h, lib/stdio-impl.h, lib/stdio.in.h:
* lib/stdlib.in.h, lib/sys_stat.in.h, lib/sys_types.in.h:
* lib/timespec.h, lib/unistd.in.h, lib/utimens.c, m4/c-strtod.m4:
* m4/gnulib-common.m4, m4/inttypes.m4, m4/lstat.m4, m4/nocrash.m4:
* m4/pselect.m4, m4/readlink.m4, m4/stdio_h.m4, m4/symlink.m4:
* m4/unistd_h.m4, m4/utimens.m4:
Copy from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
125 lines
3.3 KiB
C
125 lines
3.3 KiB
C
/* getdtablesize() function: Return maximum possible file descriptor value + 1.
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Copyright (C) 2008-2018 Free Software Foundation, Inc.
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Written by Bruno Haible <bruno@clisp.org>, 2008.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#include <config.h>
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/* Specification. */
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#include <unistd.h>
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#if defined _WIN32 && ! defined __CYGWIN__
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# include <stdio.h>
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# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
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# include "msvc-inval.h"
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# endif
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# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
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static int
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_setmaxstdio_nothrow (int newmax)
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{
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int result;
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TRY_MSVC_INVAL
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{
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result = _setmaxstdio (newmax);
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}
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CATCH_MSVC_INVAL
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{
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result = -1;
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}
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DONE_MSVC_INVAL;
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return result;
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}
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# else
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# define _setmaxstdio_nothrow _setmaxstdio
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# endif
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/* Cache for the previous getdtablesize () result. Safe to cache because
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Windows also lacks setrlimit. */
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static int dtablesize;
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int
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getdtablesize (void)
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{
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if (dtablesize == 0)
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{
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/* We are looking for the number N such that the valid file descriptors
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are 0..N-1. It can be obtained through a loop as follows:
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{
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int fd;
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for (fd = 3; fd < 65536; fd++)
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if (dup2 (0, fd) == -1)
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break;
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return fd;
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}
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On Windows XP, the result is 2048.
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The drawback of this loop is that it allocates memory for a libc
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internal array that is never freed.
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The number N can also be obtained as the upper bound for
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_getmaxstdio (). _getmaxstdio () returns the maximum number of open
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FILE objects. The sanity check in _setmaxstdio reveals the maximum
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number of file descriptors. This too allocates memory, but it is
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freed when we call _setmaxstdio with the original value. */
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int orig_max_stdio = _getmaxstdio ();
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unsigned int bound;
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for (bound = 0x10000; _setmaxstdio_nothrow (bound) < 0; bound = bound / 2)
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;
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_setmaxstdio_nothrow (orig_max_stdio);
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dtablesize = bound;
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}
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return dtablesize;
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}
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#else
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# include <limits.h>
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# include <sys/resource.h>
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# ifndef RLIM_SAVED_CUR
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# define RLIM_SAVED_CUR RLIM_INFINITY
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# endif
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# ifndef RLIM_SAVED_MAX
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# define RLIM_SAVED_MAX RLIM_INFINITY
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# endif
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# ifdef __CYGWIN__
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/* Cygwin 1.7.25 auto-increases the RLIMIT_NOFILE soft limit until it
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hits the compile-time constant hard limit of 3200. We might as
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well just report the hard limit. */
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# define rlim_cur rlim_max
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# endif
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int
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getdtablesize (void)
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{
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struct rlimit lim;
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if (getrlimit (RLIMIT_NOFILE, &lim) == 0
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&& 0 <= lim.rlim_cur && lim.rlim_cur <= INT_MAX
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&& lim.rlim_cur != RLIM_INFINITY
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&& lim.rlim_cur != RLIM_SAVED_CUR
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&& lim.rlim_cur != RLIM_SAVED_MAX)
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return lim.rlim_cur;
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return INT_MAX;
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}
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#endif
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