mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-19 06:23:34 +08:00
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.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA.
|
|
|
|
As a special exception, if you link the code in this file with
|
|
files compiled with a GNU compiler to produce an executable,
|
|
that does not cause the resulting executable to be covered by
|
|
the GNU Lesser General Public License. This exception does not
|
|
however invalidate any other reasons why the executable file
|
|
might be covered by the GNU Lesser General Public License.
|
|
This exception applies to code released by its copyright holders
|
|
in files containing the exception. */
|
|
|
|
#include "libioP.h"
|
|
#ifdef __STDC__
|
|
#include <stdlib.h>
|
|
#include <stddef.h>
|
|
#endif
|
|
#ifdef _LIBC
|
|
# include <shlib-compat.h>
|
|
#else
|
|
# define _IO_new_fopen fopen
|
|
#endif
|
|
|
|
_IO_FILE *
|
|
__fopen_maybe_mmap (fp)
|
|
_IO_FILE *fp;
|
|
{
|
|
#ifdef _G_HAVE_MMAP
|
|
if ((fp->_flags2 & _IO_FLAGS2_MMAP) && (fp->_flags & _IO_NO_WRITES))
|
|
{
|
|
/* Since this is read-only, we might be able to mmap the contents
|
|
directly. We delay the decision until the first read attempt by
|
|
giving it a jump table containing functions that choose mmap or
|
|
vanilla file operations and reset the jump table accordingly. */
|
|
|
|
if (fp->_mode <= 0)
|
|
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps_maybe_mmap;
|
|
else
|
|
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps_maybe_mmap;
|
|
fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_maybe_mmap;
|
|
}
|
|
#endif
|
|
return fp;
|
|
}
|
|
|
|
|
|
_IO_FILE *
|
|
__fopen_internal (filename, mode, is32)
|
|
const char *filename;
|
|
const char *mode;
|
|
int is32;
|
|
{
|
|
struct locked_FILE
|
|
{
|
|
struct _IO_FILE_plus fp;
|
|
#ifdef _IO_MTSAFE_IO
|
|
_IO_lock_t lock;
|
|
#endif
|
|
struct _IO_wide_data wd;
|
|
} *new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
|
|
|
|
if (new_f == NULL)
|
|
return NULL;
|
|
#ifdef _IO_MTSAFE_IO
|
|
new_f->fp.file._lock = &new_f->lock;
|
|
#endif
|
|
#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
|
|
_IO_no_init (&new_f->fp.file, 0, 0, &new_f->wd, &INTUSE(_IO_wfile_jumps));
|
|
#else
|
|
_IO_no_init (&new_f->fp.file, 1, 0, NULL, NULL);
|
|
#endif
|
|
_IO_JUMPS (&new_f->fp) = &INTUSE(_IO_file_jumps);
|
|
INTUSE(_IO_file_init) (&new_f->fp);
|
|
#if !_IO_UNIFIED_JUMPTABLES
|
|
new_f->fp.vtable = NULL;
|
|
#endif
|
|
if (INTUSE(_IO_file_fopen) ((_IO_FILE *) new_f, filename, mode, is32)
|
|
!= NULL)
|
|
return __fopen_maybe_mmap (&new_f->fp.file);
|
|
|
|
INTUSE(_IO_un_link) (&new_f->fp);
|
|
free (new_f);
|
|
return NULL;
|
|
}
|
|
|
|
_IO_FILE *
|
|
_IO_new_fopen (filename, mode)
|
|
const char *filename;
|
|
const char *mode;
|
|
{
|
|
return __fopen_internal (filename, mode, 1);
|
|
}
|
|
|
|
#ifdef _LIBC
|
|
strong_alias (_IO_new_fopen, __new_fopen)
|
|
versioned_symbol (libc, _IO_new_fopen, _IO_fopen, GLIBC_2_1);
|
|
versioned_symbol (libc, __new_fopen, fopen, GLIBC_2_1);
|
|
#endif
|