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dd0ee2e102
2002-08-29 Ulrich Drepper <drepper@redhat.com> * libio/fileops.c (_IO_new_file_fopen): Recognize new mode specifier 'm' to enable mmap I/O. * libio/libio.h (_IO_FILE): Rename _blksize field to _flags2. The former wasn't used (anymore?). (_IO_FLAGS2_MMAP): New define. * libio/genops.c (_IO_no_init): Initialize _flags2 field. * libio/iofopen.c (__fopen_maybe_mmap): Use mmap callbacks only if _IO_FLAGS2_MMAP bit is set. * libio/iofdopen.c (_IO_new_fdopen): Recognize 'm' mode specifier. Enable mmap-using mode only if 'm' was set.
114 lines
3.5 KiB
C
114 lines
3.5 KiB
C
/* Copyright (C) 1993,1997,1998,1999,2000,2002 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA.
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As a special exception, if you link the code in this file with
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files compiled with a GNU compiler to produce an executable,
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that does not cause the resulting executable to be covered by
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the GNU Lesser General Public License. This exception does not
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however invalidate any other reasons why the executable file
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might be covered by the GNU Lesser General Public License.
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This exception applies to code released by its copyright holders
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in files containing the exception. */
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#include "libioP.h"
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#ifdef __STDC__
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#include <stdlib.h>
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#include <stddef.h>
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#endif
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#ifdef _LIBC
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# include <shlib-compat.h>
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#else
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# define _IO_new_fopen fopen
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#endif
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_IO_FILE *
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__fopen_maybe_mmap (fp)
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_IO_FILE *fp;
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{
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#ifdef _G_HAVE_MMAP
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if ((fp->_flags2 & _IO_FLAGS2_MMAP) && (fp->_flags & _IO_NO_WRITES))
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{
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/* Since this is read-only, we might be able to mmap the contents
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directly. We delay the decision until the first read attempt by
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giving it a jump table containing functions that choose mmap or
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vanilla file operations and reset the jump table accordingly. */
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if (fp->_mode <= 0)
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_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps_maybe_mmap;
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else
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_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps_maybe_mmap;
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fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_maybe_mmap;
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}
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#endif
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return fp;
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}
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_IO_FILE *
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__fopen_internal (filename, mode, is32)
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const char *filename;
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const char *mode;
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int is32;
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{
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struct locked_FILE
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{
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struct _IO_FILE_plus fp;
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#ifdef _IO_MTSAFE_IO
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_IO_lock_t lock;
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#endif
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struct _IO_wide_data wd;
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} *new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
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if (new_f == NULL)
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return NULL;
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#ifdef _IO_MTSAFE_IO
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new_f->fp.file._lock = &new_f->lock;
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#endif
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#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
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_IO_no_init (&new_f->fp.file, 0, 0, &new_f->wd, &INTUSE(_IO_wfile_jumps));
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#else
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_IO_no_init (&new_f->fp.file, 1, 0, NULL, NULL);
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#endif
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_IO_JUMPS (&new_f->fp) = &INTUSE(_IO_file_jumps);
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INTUSE(_IO_file_init) (&new_f->fp);
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#if !_IO_UNIFIED_JUMPTABLES
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new_f->fp.vtable = NULL;
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#endif
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if (INTUSE(_IO_file_fopen) ((_IO_FILE *) new_f, filename, mode, is32)
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!= NULL)
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return __fopen_maybe_mmap (&new_f->fp.file);
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INTUSE(_IO_un_link) (&new_f->fp);
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free (new_f);
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return NULL;
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}
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_IO_FILE *
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_IO_new_fopen (filename, mode)
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const char *filename;
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const char *mode;
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{
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return __fopen_internal (filename, mode, 1);
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}
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#ifdef _LIBC
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strong_alias (_IO_new_fopen, __new_fopen)
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versioned_symbol (libc, _IO_new_fopen, _IO_fopen, GLIBC_2_1);
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versioned_symbol (libc, __new_fopen, fopen, GLIBC_2_1);
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#endif
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