rom/dos/changemode.c

   1 /*
   2     Copyright © 1995-2008, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Change the mode of a filehandle or lock.
   6     Lang: English
   7 */
   8 #include <proto/exec.h>
   9 #include <dos/dosextens.h>
  10 #include <dos/filesystem.h>
  11 #include "dos_intern.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <proto/dos.h>
  17
  18         AROS_LH3(BOOL, ChangeMode,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(ULONG, type,    D1),
  22         AROS_LHA(BPTR,  object,  D2),
  23         AROS_LHA(ULONG, newmode, D3),
  24
  25 /*  LOCATION */
  26         struct DosLibrary *, DOSBase, 75, Dos)
  27
  28 /*  FUNCTION
  29         Try to change the access mode of a lock or filehandle.
  30
  31     INPUTS
  32         type    - CHANGE_FH or CHANGE_LOCK.
  33         object  - Filehandle or lock.
  34         newmode - New mode, either SHARED_LOCK or EXCLUSIVE_LOCK.
  35
  36     RESULT
  37         != 0 if all went well, otherwise 0. IoErr() gives additional
  38         information in the latter case.
  39
  40     NOTES
  41
  42     EXAMPLE
  43
  44     BUGS
  45
  46     SEE ALSO
  47
  48     INTERNALS
  49         Since filehandles and locks are identical under AROS the type
  50         argument is ignored.
  51
  52 *****************************************************************************/
  53 {
  54     AROS_LIBFUNC_INIT
  55
  56     /* Get pointer to filehandle */
  57     struct FileHandle *fh = (struct FileHandle *)BADDR(object);
  58
  59     /* Get pointer to I/O request. Use stackspace for now. */
  60     struct IOFileSys iofs;
  61
  62     /* Prepare I/O request. */
  63     InitIOFS(&iofs, FSA_FILE_MODE, DOSBase);
  64
  65     iofs.IOFS.io_Device = fh->fh_Device;
  66     iofs.IOFS.io_Unit   = fh->fh_Unit;
  67
  68     iofs.io_Union.io_FILE_MODE.io_FileMode =
  69         (newmode == EXCLUSIVE_LOCK) ? FMF_LOCK : 0;
  70     iofs.io_Union.io_FILE_MODE.io_Mask = FMF_LOCK;
  71
  72     /* Send the request. */
  73     DosDoIO(&iofs.IOFS);
  74
  75     /* Set error code and return */
  76     if (iofs.io_DosError != 0)
  77     {
  78         SetIoErr(iofs.io_DosError);
  79         return DOSFALSE;
  80     }
  81
  82     return DOSTRUE;
  83
  84     AROS_LIBFUNC_EXIT
  85 } /* ChangeMode */