NT4/private/crt32/lowio/osfinfo.c
2020-09-30 17:12:29 +02:00

320 lines
8.0 KiB
C

/***
*osfinfo.c - Win32 _osfhnd[] support routines
*
* Copyright (c) 1990-1993, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Defines the internally used routine _alloc_osfhnd()
* and the user visible routine _get_osfhandle().
*
*Revision History:
* 11-16-90 GJF What can I say? The custom heap business was getting
* a little slow...
* 12-03-90 GJF Fixed my stupid syntax errors.
* 12-06-90 SRW Changed to use _osfile and _osfhnd instead of _osfinfo
* 12-28-90 SRW Added cast of void * to char * for Mips C Compiler
* 02-18-91 SRW Fixed bug in _alloc_osfhnd with setting FOPEN bit
* (only caller should do that) [_WIN32_]
* 02-18-91 SRW Fixed bug in _alloc_osfhnd with checking against
* _NFILE_ instead of _nfile [_WIN32_]
* 02-18-91 SRW Added debug output to _alloc_osfhnd if out of
* file handles. [_WIN32_]
* 02-25-91 SRW Renamed _get_free_osfhnd to be _alloc_osfhnd [_WIN32_]
* 02-25-91 SRW Exposed _get_osfhandle and _open_osfhandle [_WIN32_]
* 08-08-91 GJF Use ANSI-fied form of constant names.
* 11-25-91 GJF Lock fh before checking whether it's free.
* 12-31-91 GJF Improved multi-thread lock usage [_WIN32_].
* 02-13-92 GJF Replaced _nfile with _nhandle
* 07-15-92 GJF Fixed setting of flags in _open_osfhnd.
* 02-19-93 GJF If GetFileType fails in _open_osfhandle, don't unlock
* fh (it wasn't locked)!
*
*******************************************************************************/
#ifdef _WIN32_
#include <cruntime.h>
#include <errno.h>
#include <internal.h>
#include <fcntl.h>
#include <msdos.h>
#include <os2dll.h>
#include <stdlib.h>
#include <oscalls.h>
/***
*int _alloc_osfhnd() - get free _osfhnd[] entry
*
*Purpose:
* Finds the first free entry in _osfhnd[], mark it in use and return
* the index of the entry to the caller.
*
*Entry:
* none
*
*Exit:
* returns index of entry in fh, if successful
* return -1, if no free entry is found in _osfhnd[].
*
* MULTITHREAD NOTE: IF SUCCESSFUL, THE HANDLE IS LOCKED WHEN IT IS
* RETURNED TO THE CALLER!
*
*Exceptions:
*
*******************************************************************************/
int _CRTAPI1 _alloc_osfhnd(
void
)
{
int fh; /* _osfhnd[] index */
_mlock(_OSFHND_LOCK); /* lock the _osfhnd[] table */
/*
* search _osfhnd[] for an entry that is not currently being used.
* if one is found, mark it in use and set the _osfhandle field to
* INVALID_HANDLE_VALUE.
*/
for ( fh = 0 ; fh < _nhandle ; fh++ ) {
if ( (_osfile[fh] & FOPEN) == 0 ) {
#ifdef MTHREAD
_lock_fh(fh);
/*
* make sure the entry is still free
*/
if ( (_osfile[fh] & FOPEN) != 0 ) {
/*
* entry now in use! release the lock and
* continue looping.
*/
_unlock_fh(fh);
continue;
}
#endif
/*
* free entry found! initialize it and
* break out of the loop
*/
_osfhnd[fh] = (long)INVALID_HANDLE_VALUE;
break;
}
}
_munlock(_OSFHND_LOCK); /* unlock the _osfhnd[] table */
#if defined(DEBUG) && defined(_WIN32_)
if (fh >= _nhandle) {
DbgPrint( "WINCRT: more than %d open files\n", _nhandle );
}
#endif
/*
* return the index of the previously free table entry, if one was
* found. return -1 otherwise.
*/
return( (fh >= _nhandle) ? -1 : fh );
}
/***
*int _set_osfhnd(int fh) - set OS file handle table value
*
*Purpose:
* If fh is in range and if _osfhnd[fh] is marked with
* INVALID_HANDLE_VALUE then set _osfhnd[fh] to the passed value.
*
*Entry:
* int fh - index of _osfhnd[] entry
* long fh - new value of this handle entry
*
*Exit:
* Returns zero if successful.
* Returns -1 and sets errno to EBADF otherwise.
*
*Exceptions:
*
*******************************************************************************/
int _CRTAPI1 _set_osfhnd (
int fh, /* index into _osfhnd[] (user's file handle) */
long value
)
{
if ( ((unsigned)fh < (unsigned)_nhandle) &&
(_osfhnd[fh] == (long)INVALID_HANDLE_VALUE)
) {
switch (fh) {
case 0: SetStdHandle( STD_INPUT_HANDLE, (HANDLE)value ); break;
case 1: SetStdHandle( STD_OUTPUT_HANDLE, (HANDLE)value ); break;
case 2: SetStdHandle( STD_ERROR_HANDLE, (HANDLE)value ); break;
}
_osfhnd[fh] = value;
return(0);
} else {
errno = EBADF; /* bad handle */
_doserrno = 0L; /* not an OS error */
return -1;
}
}
/***
*int _free_osfhnd(int fh) - free OS file handle table entry
*
*Purpose:
* If fh is in range and if _osfhnd[fh] is in use and NOT marked
* with 0xfffffff
*
*Entry:
* int fh - index of _osfhnd[] entry
*
*Exit:
* Returns zero if successful.
* Returns -1 and sets errno to EBADF otherwise.
*
*Exceptions:
*
*******************************************************************************/
int _CRTAPI1 _free_osfhnd (
int fh /* index into _osfhnd[] (user's file handle) */
)
{
if ( ((unsigned)fh < (unsigned)_nhandle) &&
(_osfile[fh] & FOPEN) &&
(_osfhnd[fh] != (long)INVALID_HANDLE_VALUE)
) {
switch (fh) {
case 0: SetStdHandle( STD_INPUT_HANDLE, NULL ); break;
case 1: SetStdHandle( STD_OUTPUT_HANDLE, NULL ); break;
case 2: SetStdHandle( STD_ERROR_HANDLE, NULL ); break;
}
_osfhnd[fh] = (long)INVALID_HANDLE_VALUE;
return(0);
} else {
errno = EBADF; /* bad handle */
_doserrno = 0L; /* not an OS error */
return -1;
}
}
/***
*long _get_osfhandle(int fh) - get OS file handle
*
*Purpose:
* If fh is in range and if _osfhnd[fh] is marked free, return
* _osfhnd[fh]
*
*Entry:
* int fh - index of _osfhnd[] entry
*
*Exit:
* Returns the OS file handle if successful.
* Returns -1 and sets errno to EBADF otherwise.
*
*Exceptions:
*
*******************************************************************************/
long _CRTAPI1 _get_osfhandle (
int fh /* index into _osfhnd[] (user's file handle) */
)
{
if ( ((unsigned)fh < (unsigned)_nhandle) && (_osfile[fh] & FOPEN) )
return(_osfhnd[fh]);
else {
errno = EBADF; /* bad handle */
_doserrno = 0L; /* not an OS error */
return -1;
}
}
/***
*int _open_osfhandle(long osfhandle, int flags) - open C Runtime file handle
*
*Purpose:
* This function allocates a free C Runtime file handle and sets it
* to point to the Win32 file handle specified by the first parameter.
*
*Entry:
* long osfhandle -Win32 file handle to associate with C Runtime file handle.
* int flags - flags to associate with C Runtime file handle.
*
*Exit:
* returns index of entry in fh, if successful
* return -1, if no free entry is found in _osfhnd[].
*
*Exceptions:
*
*******************************************************************************/
int _CRTAPI1 _open_osfhandle(
long osfhandle,
int flags
)
{
int fh;
char fileflags; /* _osfile flags */
DWORD isdev; /* device indicator in low byte */
/* copy relevant flags from second parameter */
fileflags = 0;
if ( flags & _O_APPEND )
fileflags |= FAPPEND;
if ( flags & _O_TEXT )
fileflags |= FTEXT;
/* find out what type of file (file/device/pipe) */
isdev = GetFileType((HANDLE)osfhandle);
if (isdev == FILE_TYPE_UNKNOWN) {
/* OS error */
_dosmaperr( GetLastError() ); /* map error */
return -1;
}
/* is isdev value to set flags */
if (isdev == FILE_TYPE_CHAR)
fileflags |= FDEV;
else if (isdev == FILE_TYPE_PIPE)
fileflags |= FPIPE;
/* attempt to allocate a C Runtime file handle */
if ( (fh = _alloc_osfhnd()) == -1 ) {
errno = EMFILE; /* too many open files */
_doserrno = 0L; /* not an OS error */
return -1; /* return error to caller */
}
/*
* the file is open. now, set the info in _osfhnd array
*/
_set_osfhnd(fh, osfhandle);
fileflags |= FOPEN; /* mark as open */
_osfile[fh] = fileflags; /* set osfile entry */
_unlock_fh(fh); /* unlock handle */
return fh; /* return handle */
}
#else
#error ERROR - WIN32 TARGET ONLY!
#endif