windows-xp/Source/XPSP1/NT/base/crts/crtw32/stdio/_file.c

/***
*_file.c - Definition of _iob[], initializer and terminator.
*
*       Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       Defines _iob[], the array of stdio control structures, the initializer
*       and terminator routines, and the multithread locking for stdio.
*
*Revision History:
*       04-18-84  RN    initial version
*       ??-??-??  TC    added field _bifsiz to iob2 to allow variable
*                       length buffers
*       10-02-86  SKS   _NFILE_ is now different for real-mode and prot-mode
*                       _NFILE_ must be defined by compiler -D directory
*       05-27-87  JCR   Protected mode now uses only 3 pre-defined file handles,
*                       not 5.  Added PM (prot mode) to conditionalize handles.
*       06-24-87  SKS   Make "_bufin[]" and "_bufout[]" near for Compact/Large
*                       models (MS real-mode version only)
*       07-01-87  PHG   Changed PM switch to PROTMODE
*       11-05-87  JCR   Added _buferr and modified stderr entry
*       11-09-87  SKS   Removed IBMC20 switch, Changed PROTMODE to OS2
*       01-04-88  JCR   Moved _NFILE_ definition from command line to file
*       01-11-88  JCR   Merged Mthread version into standard version
*       01-21-88  JCR   Removed reference to internal.h and added _NEAR_
*                       (thus, internal.h doesn't get released in startup
*                       sources even though _file.c does).
*       06-28-88  JCR   Remove static stdout/stderr buffers
*       07-06-88  JCR   Corrected _bufin declaration so it's always in BSS
*       08-24-88  GJF   Added check that OS2 is defined whenever M_I386 is.
*       06-08-89  GJF   Propagated SKS's fix of 02-08-89, and fixed copyright.
*       07-25-89  GJF   Cleanup (deleted DOS specific and OS/2 286 specific
*                       stuff). Now specific to the 386.
*       01-09-90  GJF   _iob[], _iob2[] merge. Also, fixed copyright
*       03-16-90  GJF   Added #include <cruntime.h> and removed some (now)
*                       useless preprocessor stuff.
*       03-26-90  GJF   Replaced _cdecl with _VARTYPE1.
*       02-14-92  GJF   Replaced _NFILE_ with _NSTREAM_ for Win32, with _NFILE
*                       for non-Win32.
*       04-06-93  SKS   Replace _CRTAPI* with __cdecl
*       05-11-93  GJF   Replaced BUFSIZ with _INTERNAL_BUFSIZ.
*       04-04-94  GJF   #ifndef-ed out for Win32S version of msvcrt*.dll.
*                       Also, deleted old conditionals for non-Win32 support.
*       08-18-94  GJF   Moved stdio terminator stuff from fflush.c to here
*                       and added an initializer which fixes the _file field
*                       of _iob[0], _iob[1] and _iob[2] when the underlying
*                       entries in _osfhnd[0], _osfhnd[1], _osfhnd[2] are
*                       invalid (0 or -1).
*       02-17-95  GJF   Appended Mac version of source file (somewhat cleaned
*                       up), with appropriate #ifdef-s.
*       03-01-95  GJF   Changes to manage streams via __piob[], rather than
*                       _iob[].
*       06-12-95  GJF   Replaced _osfhnd[] with _osfhnd() (macro referencing
*                       field in ioinfo struct).
*       06-19-97  GJF   Moved _[un]lock_file[2]() here from startup\mlock.c.
*       02-13-98  GJF   Changes for Win32: changed long cast to intptr_t.
*       04-28-99  PML   Wrap __declspec(allocate()) in _CRTALLOC macro.
*       09-26-97  BWT   Fix POSIX
*       05-17-99  PML   Remove all Macintosh support.
*       01-29-01  GB    Added _func function version of data variable used in msvcprt.lib
*                       to work with STATIC_CPPLIB
*       03-27-01  PML   .CRT$XI routines must now return 0 or _RT_* fatal
*                       error code (vs7#231220)
*
*******************************************************************************/

#include <sect_attribs.h>
#include <cruntime.h>
#include <windows.h>
#include <stdio.h>
#include <file2.h>
#include <internal.h>
#include <malloc.h>
#include <rterr.h>
#include <dbgint.h>
#include <mtdll.h>

/*
 * Buffer for stdin.
 */

char _bufin[_INTERNAL_BUFSIZ];

/*
 * FILE descriptors; preset for stdin/out/err (note that the __tmpnum field
 * is not initialized)
 */
FILE _iob[_IOB_ENTRIES] = {
        /* _ptr, _cnt, _base,  _flag, _file, _charbuf, _bufsiz */

        /* stdin (_iob[0]) */

        { _bufin, 0, _bufin, _IOREAD | _IOYOURBUF, 0, 0, _INTERNAL_BUFSIZ },

        /* stdout (_iob[1]) */

        { NULL, 0, NULL, _IOWRT, 1, 0, 0 },

        /* stderr (_iob[3]) */

        { NULL, 0, NULL, _IOWRT, 2, 0, 0 },

};


/* These functions are for enabling STATIC_CPPLIB functionality */
_CRTIMP FILE * __cdecl __iob_func(void)
{
    return _iob;
}


/*
 * Pointer to array of FILE * or _FILEX * structures.
 */
void ** __piob;

/*
 * Number of open streams (set to _NSTREAM by default)
 */
#ifdef  CRTDLL
int _nstream = _NSTREAM_;
#else
int _nstream;
#endif


/*
 * Initializer and terminator for stdio
 */
int  __cdecl __initstdio(void);
void __cdecl __endstdio(void);

#ifdef  _MSC_VER

#pragma data_seg(".CRT$XIC")
_CRTALLOC(".CRT$XIC") static _PIFV pinit = __initstdio;

#pragma data_seg(".CRT$XPX")
_CRTALLOC(".CRT$XPX") static _PVFV pterm = __endstdio;

#pragma data_seg()

#endif  /* _MSC_VER */

#ifndef CRTDLL
/*
 * _cflush is a dummy variable used to pull in _endstdio() when any STDIO
 * routine is included in the user program.
 */
int _cflush = 0;
#endif  /* CRTDLL */


/***
* __initstdio - Initialize the stdio system
*
*Purpose:
*       Create and initialize the __piob array.
*
*Entry: <void>
*
*Exit:  Returns _RT_STDIOINIT if error encountered.
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/

int __cdecl __initstdio(void)
{
        int i;

#ifndef CRTDLL
        /*
         * If the user has not supplied a definition of _nstream, set it
         * to _NSTREAM_. If the user has supplied a value that is too small
         * set _nstream to the minimum acceptable value (_IOB_ENTRIES).
         */
        if ( _nstream ==  0 )
            _nstream = _NSTREAM_;
        else if ( _nstream < _IOB_ENTRIES )
            _nstream = _IOB_ENTRIES;
#endif

        /*
         * Allocate the __piob array. Try for _nstream entries first. If this
         * fails then reset _nstream to _IOB_ENTRIES and try again. If it
         * still fails, bail out with an RTE.
         */
        if ( (__piob = (void **)_calloc_crt( _nstream, sizeof(void *) )) ==
             NULL ) {
            _nstream = _IOB_ENTRIES;
            if ( (__piob = (void **)_calloc_crt( _nstream, sizeof(void *) ))
                 == NULL )
                return _RT_STDIOINIT;
        }

        /*
         * Initialize the first _IOB_ENTRIES to point to the corresponding
         * entries in _iob[].
         */
        for ( i = 0 ; i < _IOB_ENTRIES ; i++ )
            __piob[i] = (void *)&_iob[i];

#ifndef _POSIX_
        for ( i = 0 ; i < 3 ; i++ ) {
            if ( (_osfhnd(i) == (intptr_t)INVALID_HANDLE_VALUE) ||
                 (_osfhnd(i) == 0) )
            {
                _iob[i]._file = -1;
            }
        }
#endif

        return 0;
}


/***
* __endstdio - Terminate the stdio system
*
*Purpose:
*       Terminate the stdio system
*
*       (1) Flush all streams.  (Do this even if we're going to
*       call fcloseall since that routine won't do anything to the
*       std streams.)
*
*       (2) If returning to caller, close all streams.  This is
*       not necessary if the exe is terminating because the OS will
*       close the files for us (much more efficiently, too).
*
*Entry: <void>
*
*Exit:  <void>
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/

void __cdecl __endstdio(void)
{
        /* flush all streams */
        _flushall();

        /* if in callable exit, close all streams */
        if (_exitflag)
                _fcloseall();
}


#ifdef  _MT

/***
* _lock_file - Lock a FILE
*
*Purpose:
*       Assert the lock for a stdio-level file
*
*Entry:
*       pf = __piob[] entry (pointer to a FILE or _FILEX)
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

void __cdecl _lock_file (
        void *pf
        )
{
        /*
         * The way the FILE (pointed to by pf) is locked depends on whether
         * it is part of _iob[] or not
         */
        if ( (pf >= (void *)_iob) && (pf <= (void *)(&_iob[_IOB_ENTRIES-1])) )
            /*
             * FILE lies in _iob[] so the lock lies in _locktable[].
             */
            _lock( _STREAM_LOCKS + (int)((FILE *)pf - _iob) );
        else
            /*
             * Not part of _iob[]. Therefore, *pf is a _FILEX and the
             * lock field of the struct is an initialized critical
             * section.
             */
            EnterCriticalSection( &(((_FILEX *)pf)->lock) );
}


/***
* _lock_file2(i, s) - Lock the FILE
*
*Purpose:
*       Assert the lock for a stdio-level file given by s == __piob[i].
*
*Entry:
*       s == __piob[i]
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

void __cdecl _lock_file2 (
        int i,
        void *s
        )
{
        /*
         * The way the FILE is locked depends on whether it is part of _iob[]
         * _iob[] or not
         */
        if ( i < _IOB_ENTRIES )
            /*
             * FILE lies in _iob[] so the lock lies in _locktable[].
             */
            _lock( _STREAM_LOCKS + i );
        else
            /*
             * Not part of _iob[]. Therefore, *s is a _FILEX and the
             * lock field of the struct is an initialized critical
             * section.
             */
            EnterCriticalSection( &(((_FILEX *)s)->lock) );
}


/***
* _unlock_file - Unlock a FILE
*
*Purpose:
*       Release the lock for a stdio-level file
*
*Entry:
*       pf = __piob[] entry (pointer to a FILE or _FILEX)
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

void __cdecl _unlock_file (
        void *pf
        )
{
        /*
         * The way the FILE (pointed to by pf) is unlocked depends on whether
         * it is part of _iob[] or not
         */
        if ( (pf >= (void *)_iob) && (pf <= (void *)(&_iob[_IOB_ENTRIES-1])) )
            /*
             * FILE lies in _iob[] so the lock lies in _locktable[].
             */
            _unlock( _STREAM_LOCKS + (int)((FILE *)pf - _iob) );
        else
            /*
             * Not part of _iob[]. Therefore, *pf is a _FILEX and the
             * lock field of the struct is an initialized critical
             * section.
             */
            LeaveCriticalSection( &(((_FILEX *)pf)->lock) );
}


/***
* _unlock_file2(i, s) - Lock the FILE
*
*Purpose:
*       Release the lock for a stdio-level file given by s == __piob[i].
*
*Entry:
*       s == __piob[i]
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

void __cdecl _unlock_file2 (
        int i,
        void *s
        )
{
        /*
         * The way the FILE is locked depends on whether it is part of _iob[]
         * _iob[] or not
         */
        if ( i < _IOB_ENTRIES )
            /*
             * FILE lies in _iob[] so the lock lies in _locktable[].
             */
            _unlock( _STREAM_LOCKS + i );
        else
            /*
             * Not part of _iob[]. Therefore, *s is a _FILEX and the
             * lock field of the struct is an initialized critical
             * section.
             */
            LeaveCriticalSection( &(((_FILEX *)s)->lock) );
}

#endif  /* _MT */