1 /* Copyright (C) 1993,1997,1998,1999,2000,2002 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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.
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.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 As a special exception, if you link the code in this file with
20 files compiled with a GNU compiler to produce an executable,
21 that does not cause the resulting executable to be covered by
22 the GNU Lesser General Public License. This exception does not
23 however invalidate any other reasons why the executable file
24 might be covered by the GNU Lesser General Public License.
25 This exception applies to code released by its copyright holders
26 in files containing the exception. */
34 # include <shlib-compat.h>
36 # define _IO_new_fopen fopen
40 __fopen_maybe_mmap (fp
)
44 if (fp
->_flags
& _IO_NO_WRITES
)
46 /* We use the file in read-only mode. This could mean we can
47 mmap the file and use it without any copying. But not all
48 file descriptors are for mmap-able objects and on 32-bit
49 machines we don't want to map files which are too large since
50 this would require too much virtual memory. */
53 if (_IO_SYSSTAT (fp
, &st
) == 0
54 && S_ISREG (st
.st_mode
) && st
.st_size
!= 0
55 /* Limit the file size to 1MB for 32-bit machines. */
56 && (sizeof (ptrdiff_t) > 4 || st
.st_size
< 1*1024*1024))
58 /* Try to map the file. */
62 p
= _G_MMAP64 (NULL
, st
.st_size
, PROT_READ
, MAP_PRIVATE
,
65 p
= __mmap (NULL
, st
.st_size
, PROT_READ
, MAP_PRIVATE
,
70 /* OK, we managed to map the file. Set the buffer up
71 and use a special jump table with simplified
72 underflow functions which never tries to read
73 anything from the file. */
74 INTUSE(_IO_setb
) (fp
, p
, (char *) p
+ st
.st_size
, 0);
75 _IO_setg (fp
, p
, p
, p
);
78 _IO_JUMPS ((struct _IO_FILE_plus
*) fp
) = &_IO_file_jumps_mmap
;
80 _IO_JUMPS ((struct _IO_FILE_plus
*) fp
) = &_IO_wfile_jumps_mmap
;
81 fp
->_wide_data
->_wide_vtable
= &_IO_wfile_jumps_mmap
;
93 __fopen_internal (filename
, mode
, is32
)
100 struct _IO_FILE_plus fp
;
104 struct _IO_wide_data wd
;
105 } *new_f
= (struct locked_FILE
*) malloc (sizeof (struct locked_FILE
));
110 new_f
->fp
.file
._lock
= &new_f
->lock
;
112 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
113 _IO_no_init (&new_f
->fp
.file
, 0, 0, &new_f
->wd
, &INTUSE(_IO_wfile_jumps
));
115 _IO_no_init (&new_f
->fp
.file
, 1, 0, NULL
, NULL
);
117 _IO_JUMPS (&new_f
->fp
) = &INTUSE(_IO_file_jumps
);
118 INTUSE(_IO_file_init
) (&new_f
->fp
);
119 #if !_IO_UNIFIED_JUMPTABLES
120 new_f
->fp
.vtable
= NULL
;
122 if (INTUSE(_IO_file_fopen
) ((_IO_FILE
*) new_f
, filename
, mode
, is32
)
124 return __fopen_maybe_mmap (&new_f
->fp
.file
);
126 INTUSE(_IO_un_link
) (&new_f
->fp
);
132 _IO_new_fopen (filename
, mode
)
133 const char *filename
;
136 return __fopen_internal (filename
, mode
, 1);
140 strong_alias (_IO_new_fopen
, __new_fopen
)
141 versioned_symbol (libc
, _IO_new_fopen
, _IO_fopen
, GLIBC_2_1
);
142 versioned_symbol (libc
, __new_fopen
, fopen
, GLIBC_2_1
);